/* * Copyright (C) 2007 Oracle. All rights reserved. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public * License v2 as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public * License along with this program; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 021110-1307, USA. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "compat.h" #include "ctree.h" #include "disk-io.h" #include "transaction.h" #include "btrfs_inode.h" #include "ioctl.h" #include "print-tree.h" #include "volumes.h" #include "ordered-data.h" #include "xattr.h" #include "tree-log.h" #include "compression.h" #include "locking.h" #include "free-space-cache.h" #include "inode-map.h" struct btrfs_iget_args { u64 ino; struct btrfs_root *root; }; static const struct inode_operations btrfs_dir_inode_operations; static const struct inode_operations btrfs_symlink_inode_operations; static const struct inode_operations btrfs_dir_ro_inode_operations; static const struct inode_operations btrfs_special_inode_operations; static const struct inode_operations btrfs_file_inode_operations; static const struct address_space_operations btrfs_aops; static const struct address_space_operations btrfs_symlink_aops; static const struct file_operations btrfs_dir_file_operations; static struct extent_io_ops btrfs_extent_io_ops; static struct kmem_cache *btrfs_inode_cachep; struct kmem_cache *btrfs_trans_handle_cachep; struct kmem_cache *btrfs_transaction_cachep; struct kmem_cache *btrfs_path_cachep; struct kmem_cache *btrfs_free_space_cachep; #define S_SHIFT 12 static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = { [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE, [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR, [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV, [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV, [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO, [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK, [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK, }; static int btrfs_setsize(struct inode *inode, loff_t newsize); static int btrfs_truncate(struct inode *inode); static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end); static noinline int cow_file_range(struct inode *inode, struct page *locked_page, u64 start, u64 end, int *page_started, unsigned long *nr_written, int unlock); static int btrfs_init_inode_security(struct btrfs_trans_handle *trans, struct inode *inode, struct inode *dir, const struct qstr *qstr) { int err; err = btrfs_init_acl(trans, inode, dir); if (!err) err = btrfs_xattr_security_init(trans, inode, dir, qstr); return err; } /* * this does all the hard work for inserting an inline extent into * the btree. The caller should have done a btrfs_drop_extents so that * no overlapping inline items exist in the btree */ static noinline int insert_inline_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct inode *inode, u64 start, size_t size, size_t compressed_size, int compress_type, struct page **compressed_pages) { struct btrfs_key key; struct btrfs_path *path; struct extent_buffer *leaf; struct page *page = NULL; char *kaddr; unsigned long ptr; struct btrfs_file_extent_item *ei; int err = 0; int ret; size_t cur_size = size; size_t datasize; unsigned long offset; if (compressed_size && compressed_pages) cur_size = compressed_size; path = btrfs_alloc_path(); if (!path) return -ENOMEM; path->leave_spinning = 1; key.objectid = btrfs_ino(inode); key.offset = start; btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY); datasize = btrfs_file_extent_calc_inline_size(cur_size); inode_add_bytes(inode, size); ret = btrfs_insert_empty_item(trans, root, path, &key, datasize); BUG_ON(ret); if (ret) { err = ret; goto fail; } leaf = path->nodes[0]; ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); btrfs_set_file_extent_generation(leaf, ei, trans->transid); btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE); btrfs_set_file_extent_encryption(leaf, ei, 0); btrfs_set_file_extent_other_encoding(leaf, ei, 0); btrfs_set_file_extent_ram_bytes(leaf, ei, size); ptr = btrfs_file_extent_inline_start(ei); if (compress_type != BTRFS_COMPRESS_NONE) { struct page *cpage; int i = 0; while (compressed_size > 0) { cpage = compressed_pages[i]; cur_size = min_t(unsigned long, compressed_size, PAGE_CACHE_SIZE); kaddr = kmap_atomic(cpage, KM_USER0); write_extent_buffer(leaf, kaddr, ptr, cur_size); kunmap_atomic(kaddr, KM_USER0); i++; ptr += cur_size; compressed_size -= cur_size; } btrfs_set_file_extent_compression(leaf, ei, compress_type); } else { page = find_get_page(inode->i_mapping, start >> PAGE_CACHE_SHIFT); btrfs_set_file_extent_compression(leaf, ei, 0); kaddr = kmap_atomic(page, KM_USER0); offset = start & (PAGE_CACHE_SIZE - 1); write_extent_buffer(leaf, kaddr + offset, ptr, size); kunmap_atomic(kaddr, KM_USER0); page_cache_release(page); } btrfs_mark_buffer_dirty(leaf); btrfs_free_path(path); /* * we're an inline extent, so nobody can * extend the file past i_size without locking * a page we already have locked. * * We must do any isize and inode updates * before we unlock the pages. Otherwise we * could end up racing with unlink. */ BTRFS_I(inode)->disk_i_size = inode->i_size; btrfs_update_inode(trans, root, inode); return 0; fail: btrfs_free_path(path); return err; } /* * conditionally insert an inline extent into the file. This * does the checks required to make sure the data is small enough * to fit as an inline extent. */ static noinline int cow_file_range_inline(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct inode *inode, u64 start, u64 end, size_t compressed_size, int compress_type, struct page **compressed_pages) { u64 isize = i_size_read(inode); u64 actual_end = min(end + 1, isize); u64 inline_len = actual_end - start; u64 aligned_end = (end + root->sectorsize - 1) & ~((u64)root->sectorsize - 1); u64 hint_byte; u64 data_len = inline_len; int ret; if (compressed_size) data_len = compressed_size; if (start > 0 || actual_end >= PAGE_CACHE_SIZE || data_len >= BTRFS_MAX_INLINE_DATA_SIZE(root) || (!compressed_size && (actual_end & (root->sectorsize - 1)) == 0) || end + 1 < isize || data_len > root->fs_info->max_inline) { return 1; } ret = btrfs_drop_extents(trans, inode, start, aligned_end, &hint_byte, 1); BUG_ON(ret); if (isize > actual_end) inline_len = min_t(u64, isize, actual_end); ret = insert_inline_extent(trans, root, inode, start, inline_len, compressed_size, compress_type, compressed_pages); BUG_ON(ret); btrfs_delalloc_release_metadata(inode, end + 1 - start); btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0); return 0; } struct async_extent { u64 start; u64 ram_size; u64 compressed_size; struct page **pages; unsigned long nr_pages; int compress_type; struct list_head list; }; struct async_cow { struct inode *inode; struct btrfs_root *root; struct page *locked_page; u64 start; u64 end; struct list_head extents; struct btrfs_work work; }; static noinline int add_async_extent(struct async_cow *cow, u64 start, u64 ram_size, u64 compressed_size, struct page **pages, unsigned long nr_pages, int compress_type) { struct async_extent *async_extent; async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS); BUG_ON(!async_extent); async_extent->start = start; async_extent->ram_size = ram_size; async_extent->compressed_size = compressed_size; async_extent->pages = pages; async_extent->nr_pages = nr_pages; async_extent->compress_type = compress_type; list_add_tail(&async_extent->list, &cow->extents); return 0; } /* * we create compressed extents in two phases. The first * phase compresses a range of pages that have already been * locked (both pages and state bits are locked). * * This is done inside an ordered work queue, and the compression * is spread across many cpus. The actual IO submission is step * two, and the ordered work queue takes care of making sure that * happens in the same order things were put onto the queue by * writepages and friends. * * If this code finds it can't get good compression, it puts an * entry onto the work queue to write the uncompressed bytes. This * makes sure that both compressed inodes and uncompressed inodes * are written in the same order that pdflush sent them down. */ static noinline int compress_file_range(struct inode *inode, struct page *locked_page, u64 start, u64 end, struct async_cow *async_cow, int *num_added) { struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_trans_handle *trans; u64 num_bytes; u64 blocksize = root->sectorsize; u64 actual_end; u64 isize = i_size_read(inode); int ret = 0; struct page **pages = NULL; unsigned long nr_pages; unsigned long nr_pages_ret = 0; unsigned long total_compressed = 0; unsigned long total_in = 0; unsigned long max_compressed = 128 * 1024; unsigned long max_uncompressed = 128 * 1024; int i; int will_compress; int compress_type = root->fs_info->compress_type; /* if this is a small write inside eof, kick off a defragbot */ if (end <= BTRFS_I(inode)->disk_i_size && (end - start + 1) < 16 * 1024) btrfs_add_inode_defrag(NULL, inode); actual_end = min_t(u64, isize, end + 1); again: will_compress = 0; nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1; nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE); /* * we don't want to send crud past the end of i_size through * compression, that's just a waste of CPU time. So, if the * end of the file is before the start of our current * requested range of bytes, we bail out to the uncompressed * cleanup code that can deal with all of this. * * It isn't really the fastest way to fix things, but this is a * very uncommon corner. */ if (actual_end <= start) goto cleanup_and_bail_uncompressed; total_compressed = actual_end - start; /* we want to make sure that amount of ram required to uncompress * an extent is reasonable, so we limit the total size in ram * of a compressed extent to 128k. This is a crucial number * because it also controls how easily we can spread reads across * cpus for decompression. * * We also want to make sure the amount of IO required to do * a random read is reasonably small, so we limit the size of * a compressed extent to 128k. */ total_compressed = min(total_compressed, max_uncompressed); num_bytes = (end - start + blocksize) & ~(blocksize - 1); num_bytes = max(blocksize, num_bytes); total_in = 0; ret = 0; /* * we do compression for mount -o compress and when the * inode has not been flagged as nocompress. This flag can * change at any time if we discover bad compression ratios. */ if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) && (btrfs_test_opt(root, COMPRESS) || (BTRFS_I(inode)->force_compress) || (BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS))) { WARN_ON(pages); pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS); BUG_ON(!pages); if (BTRFS_I(inode)->force_compress) compress_type = BTRFS_I(inode)->force_compress; ret = btrfs_compress_pages(compress_type, inode->i_mapping, start, total_compressed, pages, nr_pages, &nr_pages_ret, &total_in, &total_compressed, max_compressed); if (!ret) { unsigned long offset = total_compressed & (PAGE_CACHE_SIZE - 1); struct page *page = pages[nr_pages_ret - 1]; char *kaddr; /* zero the tail end of the last page, we might be * sending it down to disk */ if (offset) { kaddr = kmap_atomic(page, KM_USER0); memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset); kunmap_atomic(kaddr, KM_USER0); } will_compress = 1; } } if (start == 0) { trans = btrfs_join_transaction(root); BUG_ON(IS_ERR(trans)); trans->block_rsv = &root->fs_info->delalloc_block_rsv; /* lets try to make an inline extent */ if (ret || total_in < (actual_end - start)) { /* we didn't compress the entire range, try * to make an uncompressed inline extent. */ ret = cow_file_range_inline(trans, root, inode, start, end, 0, 0, NULL); } else { /* try making a compressed inline extent */ ret = cow_file_range_inline(trans, root, inode, start, end, total_compressed, compress_type, pages); } if (ret == 0) { /* * inline extent creation worked, we don't need * to create any more async work items. Unlock * and free up our temp pages. */ extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree, start, end, NULL, EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY | EXTENT_CLEAR_DELALLOC | EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK); btrfs_end_transaction(trans, root); goto free_pages_out; } btrfs_end_transaction(trans, root); } if (will_compress) { /* * we aren't doing an inline extent round the compressed size * up to a block size boundary so the allocator does sane * things */ total_compressed = (total_compressed + blocksize - 1) & ~(blocksize - 1); /* * one last check to make sure the compression is really a * win, compare the page count read with the blocks on disk */ total_in = (total_in + PAGE_CACHE_SIZE - 1) & ~(PAGE_CACHE_SIZE - 1); if (total_compressed >= total_in) { will_compress = 0; } else { num_bytes = total_in; } } if (!will_compress && pages) { /* * the compression code ran but failed to make things smaller, * free any pages it allocated and our page pointer array */ for (i = 0; i < nr_pages_ret; i++) { WARN_ON(pages[i]->mapping); page_cache_release(pages[i]); } kfree(pages); pages = NULL; total_compressed = 0; nr_pages_ret = 0; /* flag the file so we don't compress in the future */ if (!btrfs_test_opt(root, FORCE_COMPRESS) && !(BTRFS_I(inode)->force_compress)) { BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS; } } if (will_compress) { *num_added += 1; /* the async work queues will take care of doing actual * allocation on disk for these compressed pages, * and will submit them to the elevator. */ add_async_extent(async_cow, start, num_bytes, total_compressed, pages, nr_pages_ret, compress_type); if (start + num_bytes < end) { start += num_bytes; pages = NULL; cond_resched(); goto again; } } else { cleanup_and_bail_uncompressed: /* * No compression, but we still need to write the pages in * the file we've been given so far. redirty the locked * page if it corresponds to our extent and set things up * for the async work queue to run cow_file_range to do * the normal delalloc dance */ if (page_offset(locked_page) >= start && page_offset(locked_page) <= end) { __set_page_dirty_nobuffers(locked_page); /* unlocked later on in the async handlers */ } add_async_extent(async_cow, start, end - start + 1, 0, NULL, 0, BTRFS_COMPRESS_NONE); *num_added += 1; } out: return 0; free_pages_out: for (i = 0; i < nr_pages_ret; i++) { WARN_ON(pages[i]->mapping); page_cache_release(pages[i]); } kfree(pages); goto out; } /* * phase two of compressed writeback. This is the ordered portion * of the code, which only gets called in the order the work was * queued. We walk all the async extents created by compress_file_range * and send them down to the disk. */ static noinline int submit_compressed_extents(struct inode *inode, struct async_cow *async_cow) { struct async_extent *async_extent; u64 alloc_hint = 0; struct btrfs_trans_handle *trans; struct btrfs_key ins; struct extent_map *em; struct btrfs_root *root = BTRFS_I(inode)->root; struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; struct extent_io_tree *io_tree; int ret = 0; if (list_empty(&async_cow->extents)) return 0; while (!list_empty(&async_cow->extents)) { async_extent = list_entry(async_cow->extents.next, struct async_extent, list); list_del(&async_extent->list); io_tree = &BTRFS_I(inode)->io_tree; retry: /* did the compression code fall back to uncompressed IO? */ if (!async_extent->pages) { int page_started = 0; unsigned long nr_written = 0; lock_extent(io_tree, async_extent->start, async_extent->start + async_extent->ram_size - 1, GFP_NOFS); /* allocate blocks */ ret = cow_file_range(inode, async_cow->locked_page, async_extent->start, async_extent->start + async_extent->ram_size - 1, &page_started, &nr_written, 0); /* * if page_started, cow_file_range inserted an * inline extent and took care of all the unlocking * and IO for us. Otherwise, we need to submit * all those pages down to the drive. */ if (!page_started && !ret) extent_write_locked_range(io_tree, inode, async_extent->start, async_extent->start + async_extent->ram_size - 1, btrfs_get_extent, WB_SYNC_ALL); kfree(async_extent); cond_resched(); continue; } lock_extent(io_tree, async_extent->start, async_extent->start + async_extent->ram_size - 1, GFP_NOFS); trans = btrfs_join_transaction(root); BUG_ON(IS_ERR(trans)); trans->block_rsv = &root->fs_info->delalloc_block_rsv; ret = btrfs_reserve_extent(trans, root, async_extent->compressed_size, async_extent->compressed_size, 0, alloc_hint, (u64)-1, &ins, 1); btrfs_end_transaction(trans, root); if (ret) { int i; for (i = 0; i < async_extent->nr_pages; i++) { WARN_ON(async_extent->pages[i]->mapping); page_cache_release(async_extent->pages[i]); } kfree(async_extent->pages); async_extent->nr_pages = 0; async_extent->pages = NULL; unlock_extent(io_tree, async_extent->start, async_extent->start + async_extent->ram_size - 1, GFP_NOFS); goto retry; } /* * here we're doing allocation and writeback of the * compressed pages */ btrfs_drop_extent_cache(inode, async_extent->start, async_extent->start + async_extent->ram_size - 1, 0); em = alloc_extent_map(); BUG_ON(!em); em->start = async_extent->start; em->len = async_extent->ram_size; em->orig_start = em->start; em->block_start = ins.objectid; em->block_len = ins.offset; em->bdev = root->fs_info->fs_devices->latest_bdev; em->compress_type = async_extent->compress_type; set_bit(EXTENT_FLAG_PINNED, &em->flags); set_bit(EXTENT_FLAG_COMPRESSED, &em->flags); while (1) { write_lock(&em_tree->lock); ret = add_extent_mapping(em_tree, em); write_unlock(&em_tree->lock); if (ret != -EEXIST) { free_extent_map(em); break; } btrfs_drop_extent_cache(inode, async_extent->start, async_extent->start + async_extent->ram_size - 1, 0); } ret = btrfs_add_ordered_extent_compress(inode, async_extent->start, ins.objectid, async_extent->ram_size, ins.offset, BTRFS_ORDERED_COMPRESSED, async_extent->compress_type); BUG_ON(ret); /* * clear dirty, set writeback and unlock the pages. */ extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree, async_extent->start, async_extent->start + async_extent->ram_size - 1, NULL, EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC | EXTENT_CLEAR_DIRTY | EXTENT_SET_WRITEBACK); ret = btrfs_submit_compressed_write(inode, async_extent->start, async_extent->ram_size, ins.objectid, ins.offset, async_extent->pages, async_extent->nr_pages); BUG_ON(ret); alloc_hint = ins.objectid + ins.offset; kfree(async_extent); cond_resched(); } return 0; } static u64 get_extent_allocation_hint(struct inode *inode, u64 start, u64 num_bytes) { struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; struct extent_map *em; u64 alloc_hint = 0; read_lock(&em_tree->lock); em = search_extent_mapping(em_tree, start, num_bytes); if (em) { /* * if block start isn't an actual block number then find the * first block in this inode and use that as a hint. If that * block is also bogus then just don't worry about it. */ if (em->block_start >= EXTENT_MAP_LAST_BYTE) { free_extent_map(em); em = search_extent_mapping(em_tree, 0, 0); if (em && em->block_start < EXTENT_MAP_LAST_BYTE) alloc_hint = em->block_start; if (em) free_extent_map(em); } else { alloc_hint = em->block_start; free_extent_map(em); } } read_unlock(&em_tree->lock); return alloc_hint; } /* * when extent_io.c finds a delayed allocation range in the file, * the call backs end up in this code. The basic idea is to * allocate extents on disk for the range, and create ordered data structs * in ram to track those extents. * * locked_page is the page that writepage had locked already. We use * it to make sure we don't do extra locks or unlocks. * * *page_started is set to one if we unlock locked_page and do everything * required to start IO on it. It may be clean and already done with * IO when we return. */ static noinline int cow_file_range(struct inode *inode, struct page *locked_page, u64 start, u64 end, int *page_started, unsigned long *nr_written, int unlock) { struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_trans_handle *trans; u64 alloc_hint = 0; u64 num_bytes; unsigned long ram_size; u64 disk_num_bytes; u64 cur_alloc_size; u64 blocksize = root->sectorsize; struct btrfs_key ins; struct extent_map *em; struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; int ret = 0; BUG_ON(btrfs_is_free_space_inode(root, inode)); trans = btrfs_join_transaction(root); BUG_ON(IS_ERR(trans)); trans->block_rsv = &root->fs_info->delalloc_block_rsv; num_bytes = (end - start + blocksize) & ~(blocksize - 1); num_bytes = max(blocksize, num_bytes); disk_num_bytes = num_bytes; ret = 0; /* if this is a small write inside eof, kick off defrag */ if (end <= BTRFS_I(inode)->disk_i_size && num_bytes < 64 * 1024) btrfs_add_inode_defrag(trans, inode); if (start == 0) { /* lets try to make an inline extent */ ret = cow_file_range_inline(trans, root, inode, start, end, 0, 0, NULL); if (ret == 0) { extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree, start, end, NULL, EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC | EXTENT_CLEAR_DIRTY | EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK); *nr_written = *nr_written + (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE; *page_started = 1; ret = 0; goto out; } } BUG_ON(disk_num_bytes > btrfs_super_total_bytes(&root->fs_info->super_copy)); alloc_hint = get_extent_allocation_hint(inode, start, num_bytes); btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0); while (disk_num_bytes > 0) { unsigned long op; cur_alloc_size = disk_num_bytes; ret = btrfs_reserve_extent(trans, root, cur_alloc_size, root->sectorsize, 0, alloc_hint, (u64)-1, &ins, 1); BUG_ON(ret); em = alloc_extent_map(); BUG_ON(!em); em->start = start; em->orig_start = em->start; ram_size = ins.offset; em->len = ins.offset; em->block_start = ins.objectid; em->block_len = ins.offset; em->bdev = root->fs_info->fs_devices->latest_bdev; set_bit(EXTENT_FLAG_PINNED, &em->flags); while (1) { write_lock(&em_tree->lock); ret = add_extent_mapping(em_tree, em); write_unlock(&em_tree->lock); if (ret != -EEXIST) { free_extent_map(em); break; } btrfs_drop_extent_cache(inode, start, start + ram_size - 1, 0); } cur_alloc_size = ins.offset; ret = btrfs_add_ordered_extent(inode, start, ins.objectid, ram_size, cur_alloc_size, 0); BUG_ON(ret); if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID) { ret = btrfs_reloc_clone_csums(inode, start, cur_alloc_size); BUG_ON(ret); } if (disk_num_bytes < cur_alloc_size) break; /* we're not doing compressed IO, don't unlock the first * page (which the caller expects to stay locked), don't * clear any dirty bits and don't set any writeback bits * * Do set the Private2 bit so we know this page was properly * setup for writepage */ op = unlock ? EXTENT_CLEAR_UNLOCK_PAGE : 0; op |= EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC | EXTENT_SET_PRIVATE2; extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree, start, start + ram_size - 1, locked_page, op); disk_num_bytes -= cur_alloc_size; num_bytes -= cur_alloc_size; alloc_hint = ins.objectid + ins.offset; start += cur_alloc_size; } out: ret = 0; btrfs_end_transaction(trans, root); return ret; } /* * work queue call back to started compression on a file and pages */ static noinline void async_cow_start(struct btrfs_work *work) { struct async_cow *async_cow; int num_added = 0; async_cow = container_of(work, struct async_cow, work); compress_file_range(async_cow->inode, async_cow->locked_page, async_cow->start, async_cow->end, async_cow, &num_added); if (num_added == 0) async_cow->inode = NULL; } /* * work queue call back to submit previously compressed pages */ static noinline void async_cow_submit(struct btrfs_work *work) { struct async_cow *async_cow; struct btrfs_root *root; unsigned long nr_pages; async_cow = container_of(work, struct async_cow, work); root = async_cow->root; nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >> PAGE_CACHE_SHIFT; atomic_sub(nr_pages, &root->fs_info->async_delalloc_pages); if (atomic_read(&root->fs_info->async_delalloc_pages) < 5 * 1042 * 1024 && waitqueue_active(&root->fs_info->async_submit_wait)) wake_up(&root->fs_info->async_submit_wait); if (async_cow->inode) submit_compressed_extents(async_cow->inode, async_cow); } static noinline void async_cow_free(struct btrfs_work *work) { struct async_cow *async_cow; async_cow = container_of(work, struct async_cow, work); kfree(async_cow); } static int cow_file_range_async(struct inode *inode, struct page *locked_page, u64 start, u64 end, int *page_started, unsigned long *nr_written) { struct async_cow *async_cow; struct btrfs_root *root = BTRFS_I(inode)->root; unsigned long nr_pages; u64 cur_end; int limit = 10 * 1024 * 1042; clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED, 1, 0, NULL, GFP_NOFS); while (start < end) { async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS); BUG_ON(!async_cow); async_cow->inode = inode; async_cow->root = root; async_cow->locked_page = locked_page; async_cow->start = start; if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) cur_end = end; else cur_end = min(end, start + 512 * 1024 - 1); async_cow->end = cur_end; INIT_LIST_HEAD(&async_cow->extents); async_cow->work.func = async_cow_start; async_cow->work.ordered_func = async_cow_submit; async_cow->work.ordered_free = async_cow_free; async_cow->work.flags = 0; nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >> PAGE_CACHE_SHIFT; atomic_add(nr_pages, &root->fs_info->async_delalloc_pages); btrfs_queue_worker(&root->fs_info->delalloc_workers, &async_cow->work); if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) { wait_event(root->fs_info->async_submit_wait, (atomic_read(&root->fs_info->async_delalloc_pages) < limit)); } while (atomic_read(&root->fs_info->async_submit_draining) && atomic_read(&root->fs_info->async_delalloc_pages)) { wait_event(root->fs_info->async_submit_wait, (atomic_read(&root->fs_info->async_delalloc_pages) == 0)); } *nr_written += nr_pages; start = cur_end + 1; } *page_started = 1; return 0; } static noinline int csum_exist_in_range(struct btrfs_root *root, u64 bytenr, u64 num_bytes) { int ret; struct btrfs_ordered_sum *sums; LIST_HEAD(list); ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr, bytenr + num_bytes - 1, &list, 0); if (ret == 0 && list_empty(&list)) return 0; while (!list_empty(&list)) { sums = list_entry(list.next, struct btrfs_ordered_sum, list); list_del(&sums->list); kfree(sums); } return 1; } /* * when nowcow writeback call back. This checks for snapshots or COW copies * of the extents that exist in the file, and COWs the file as required. * * If no cow copies or snapshots exist, we write directly to the existing * blocks on disk */ static noinline int run_delalloc_nocow(struct inode *inode, struct page *locked_page, u64 start, u64 end, int *page_started, int force, unsigned long *nr_written) { struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_trans_handle *trans; struct extent_buffer *leaf; struct btrfs_path *path; struct btrfs_file_extent_item *fi; struct btrfs_key found_key; u64 cow_start; u64 cur_offset; u64 extent_end; u64 extent_offset; u64 disk_bytenr; u64 num_bytes; int extent_type; int ret; int type; int nocow; int check_prev = 1; bool nolock; u64 ino = btrfs_ino(inode); path = btrfs_alloc_path(); BUG_ON(!path); nolock = btrfs_is_free_space_inode(root, inode); if (nolock) trans = btrfs_join_transaction_nolock(root); else trans = btrfs_join_transaction(root); BUG_ON(IS_ERR(trans)); trans->block_rsv = &root->fs_info->delalloc_block_rsv; cow_start = (u64)-1; cur_offset = start; while (1) { ret = btrfs_lookup_file_extent(trans, root, path, ino, cur_offset, 0); BUG_ON(ret < 0); if (ret > 0 && path->slots[0] > 0 && check_prev) { leaf = path->nodes[0]; btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0] - 1); if (found_key.objectid == ino && found_key.type == BTRFS_EXTENT_DATA_KEY) path->slots[0]--; } check_prev = 0; next_slot: leaf = path->nodes[0]; if (path->slots[0] >= btrfs_header_nritems(leaf)) { ret = btrfs_next_leaf(root, path); if (ret < 0) BUG_ON(1); if (ret > 0) break; leaf = path->nodes[0]; } nocow = 0; disk_bytenr = 0; num_bytes = 0; btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); if (found_key.objectid > ino || found_key.type > BTRFS_EXTENT_DATA_KEY || found_key.offset > end) break; if (found_key.offset > cur_offset) { extent_end = found_key.offset; extent_type = 0; goto out_check; } fi = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); extent_type = btrfs_file_extent_type(leaf, fi); if (extent_type == BTRFS_FILE_EXTENT_REG || extent_type == BTRFS_FILE_EXTENT_PREALLOC) { disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); extent_offset = btrfs_file_extent_offset(leaf, fi); extent_end = found_key.offset + btrfs_file_extent_num_bytes(leaf, fi); if (extent_end <= start) { path->slots[0]++; goto next_slot; } if (disk_bytenr == 0) goto out_check; if (btrfs_file_extent_compression(leaf, fi) || btrfs_file_extent_encryption(leaf, fi) || btrfs_file_extent_other_encoding(leaf, fi)) goto out_check; if (extent_type == BTRFS_FILE_EXTENT_REG && !force) goto out_check; if (btrfs_extent_readonly(root, disk_bytenr)) goto out_check; if (btrfs_cross_ref_exist(trans, root, ino, found_key.offset - extent_offset, disk_bytenr)) goto out_check; disk_bytenr += extent_offset; disk_bytenr += cur_offset - found_key.offset; num_bytes = min(end + 1, extent_end) - cur_offset; /* * force cow if csum exists in the range. * this ensure that csum for a given extent are * either valid or do not exist. */ if (csum_exist_in_range(root, disk_bytenr, num_bytes)) goto out_check; nocow = 1; } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { extent_end = found_key.offset + btrfs_file_extent_inline_len(leaf, fi); extent_end = ALIGN(extent_end, root->sectorsize); } else { BUG_ON(1); } out_check: if (extent_end <= start) { path->slots[0]++; goto next_slot; } if (!nocow) { if (cow_start == (u64)-1) cow_start = cur_offset; cur_offset = extent_end; if (cur_offset > end) break; path->slots[0]++; goto next_slot; } btrfs_release_path(path); if (cow_start != (u64)-1) { ret = cow_file_range(inode, locked_page, cow_start, found_key.offset - 1, page_started, nr_written, 1); BUG_ON(ret); cow_start = (u64)-1; } if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) { struct extent_map *em; struct extent_map_tree *em_tree; em_tree = &BTRFS_I(inode)->extent_tree; em = alloc_extent_map(); BUG_ON(!em); em->start = cur_offset; em->orig_start = em->start; em->len = num_bytes; em->block_len = num_bytes; em->block_start = disk_bytenr; em->bdev = root->fs_info->fs_devices->latest_bdev; set_bit(EXTENT_FLAG_PINNED, &em->flags); while (1) { write_lock(&em_tree->lock); ret = add_extent_mapping(em_tree, em); write_unlock(&em_tree->lock); if (ret != -EEXIST) { free_extent_map(em); break; } btrfs_drop_extent_cache(inode, em->start, em->start + em->len - 1, 0); } type = BTRFS_ORDERED_PREALLOC; } else { type = BTRFS_ORDERED_NOCOW; } ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr, num_bytes, num_bytes, type); BUG_ON(ret); if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID) { ret = btrfs_reloc_clone_csums(inode, cur_offset, num_bytes); BUG_ON(ret); } extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree, cur_offset, cur_offset + num_bytes - 1, locked_page, EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC | EXTENT_SET_PRIVATE2); cur_offset = extent_end; if (cur_offset > end) break; } btrfs_release_path(path); if (cur_offset <= end && cow_start == (u64)-1) cow_start = cur_offset; if (cow_start != (u64)-1) { ret = cow_file_range(inode, locked_page, cow_start, end, page_started, nr_written, 1); BUG_ON(ret); } if (nolock) { ret = btrfs_end_transaction_nolock(trans, root); BUG_ON(ret); } else { ret = btrfs_end_transaction(trans, root); BUG_ON(ret); } btrfs_free_path(path); return 0; } /* * extent_io.c call back to do delayed allocation processing */ static int run_delalloc_range(struct inode *inode, struct page *locked_page, u64 start, u64 end, int *page_started, unsigned long *nr_written) { int ret; struct btrfs_root *root = BTRFS_I(inode)->root; if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) ret = run_delalloc_nocow(inode, locked_page, start, end, page_started, 1, nr_written); else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC) ret = run_delalloc_nocow(inode, locked_page, start, end, page_started, 0, nr_written); else if (!btrfs_test_opt(root, COMPRESS) && !(BTRFS_I(inode)->force_compress) && !(BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS)) ret = cow_file_range(inode, locked_page, start, end, page_started, nr_written, 1); else ret = cow_file_range_async(inode, locked_page, start, end, page_started, nr_written); return ret; } static int btrfs_split_extent_hook(struct inode *inode, struct extent_state *orig, u64 split) { /* not delalloc, ignore it */ if (!(orig->state & EXTENT_DELALLOC)) return 0; spin_lock(&BTRFS_I(inode)->lock); BTRFS_I(inode)->outstanding_extents++; spin_unlock(&BTRFS_I(inode)->lock); return 0; } /* * extent_io.c merge_extent_hook, used to track merged delayed allocation * extents so we can keep track of new extents that are just merged onto old * extents, such as when we are doing sequential writes, so we can properly * account for the metadata space we'll need. */ static int btrfs_merge_extent_hook(struct inode *inode, struct extent_state *new, struct extent_state *other) { /* not delalloc, ignore it */ if (!(other->state & EXTENT_DELALLOC)) return 0; spin_lock(&BTRFS_I(inode)->lock); BTRFS_I(inode)->outstanding_extents--; spin_unlock(&BTRFS_I(inode)->lock); return 0; } /* * extent_io.c set_bit_hook, used to track delayed allocation * bytes in this file, and to maintain the list of inodes that * have pending delalloc work to be done. */ static int btrfs_set_bit_hook(struct inode *inode, struct extent_state *state, int *bits) { /* * set_bit and clear bit hooks normally require _irqsave/restore * but in this case, we are only testing for the DELALLOC * bit, which is only set or cleared with irqs on */ if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) { struct btrfs_root *root = BTRFS_I(inode)->root; u64 len = state->end + 1 - state->start; bool do_list = !btrfs_is_free_space_inode(root, inode); if (*bits & EXTENT_FIRST_DELALLOC) { *bits &= ~EXTENT_FIRST_DELALLOC; } else { spin_lock(&BTRFS_I(inode)->lock); BTRFS_I(inode)->outstanding_extents++; spin_unlock(&BTRFS_I(inode)->lock); } spin_lock(&root->fs_info->delalloc_lock); BTRFS_I(inode)->delalloc_bytes += len; root->fs_info->delalloc_bytes += len; if (do_list && list_empty(&BTRFS_I(inode)->delalloc_inodes)) { list_add_tail(&BTRFS_I(inode)->delalloc_inodes, &root->fs_info->delalloc_inodes); } spin_unlock(&root->fs_info->delalloc_lock); } return 0; } /* * extent_io.c clear_bit_hook, see set_bit_hook for why */ static int btrfs_clear_bit_hook(struct inode *inode, struct extent_state *state, int *bits) { /* * set_bit and clear bit hooks normally require _irqsave/restore * but in this case, we are only testing for the DELALLOC * bit, which is only set or cleared with irqs on */ if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) { struct btrfs_root *root = BTRFS_I(inode)->root; u64 len = state->end + 1 - state->start; bool do_list = !btrfs_is_free_space_inode(root, inode); if (*bits & EXTENT_FIRST_DELALLOC) { *bits &= ~EXTENT_FIRST_DELALLOC; } else if (!(*bits & EXTENT_DO_ACCOUNTING)) { spin_lock(&BTRFS_I(inode)->lock); BTRFS_I(inode)->outstanding_extents--; spin_unlock(&BTRFS_I(inode)->lock); } if (*bits & EXTENT_DO_ACCOUNTING) btrfs_delalloc_release_metadata(inode, len); if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID && do_list) btrfs_free_reserved_data_space(inode, len); spin_lock(&root->fs_info->delalloc_lock); root->fs_info->delalloc_bytes -= len; BTRFS_I(inode)->delalloc_bytes -= len; if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 && !list_empty(&BTRFS_I(inode)->delalloc_inodes)) { list_del_init(&BTRFS_I(inode)->delalloc_inodes); } spin_unlock(&root->fs_info->delalloc_lock); } return 0; } /* * extent_io.c merge_bio_hook, this must check the chunk tree to make sure * we don't create bios that span stripes or chunks */ int btrfs_merge_bio_hook(struct page *page, unsigned long offset, size_t size, struct bio *bio, unsigned long bio_flags) { struct btrfs_root *root = BTRFS_I(page->mapping->host)->root; struct btrfs_mapping_tree *map_tree; u64 logical = (u64)bio->bi_sector << 9; u64 length = 0; u64 map_length; int ret; if (bio_flags & EXTENT_BIO_COMPRESSED) return 0; length = bio->bi_size; map_tree = &root->fs_info->mapping_tree; map_length = length; ret = btrfs_map_block(map_tree, READ, logical, &map_length, NULL, 0); if (map_length < length + size) return 1; return ret; } /* * in order to insert checksums into the metadata in large chunks, * we wait until bio submission time. All the pages in the bio are * checksummed and sums are attached onto the ordered extent record. * * At IO completion time the cums attached on the ordered extent record * are inserted into the btree */ static int __btrfs_submit_bio_start(struct inode *inode, int rw, struct bio *bio, int mirror_num, unsigned long bio_flags, u64 bio_offset) { struct btrfs_root *root = BTRFS_I(inode)->root; int ret = 0; ret = btrfs_csum_one_bio(root, inode, bio, 0, 0); BUG_ON(ret); return 0; } /* * in order to insert checksums into the metadata in large chunks, * we wait until bio submission time. All the pages in the bio are * checksummed and sums are attached onto the ordered extent record. * * At IO completion time the cums attached on the ordered extent record * are inserted into the btree */ static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio, int mirror_num, unsigned long bio_flags, u64 bio_offset) { struct btrfs_root *root = BTRFS_I(inode)->root; return btrfs_map_bio(root, rw, bio, mirror_num, 1); } /* * extent_io.c submission hook. This does the right thing for csum calculation * on write, or reading the csums from the tree before a read */ static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio, int mirror_num, unsigned long bio_flags, u64 bio_offset) { struct btrfs_root *root = BTRFS_I(inode)->root; int ret = 0; int skip_sum; skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM; if (btrfs_is_free_space_inode(root, inode)) ret = btrfs_bio_wq_end_io(root->fs_info, bio, 2); else ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0); BUG_ON(ret); if (!(rw & REQ_WRITE)) { if (bio_flags & EXTENT_BIO_COMPRESSED) { return btrfs_submit_compressed_read(inode, bio, mirror_num, bio_flags); } else if (!skip_sum) { ret = btrfs_lookup_bio_sums(root, inode, bio, NULL); if (ret) return ret; } goto mapit; } else if (!skip_sum) { /* csum items have already been cloned */ if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID) goto mapit; /* we're doing a write, do the async checksumming */ return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info, inode, rw, bio, mirror_num, bio_flags, bio_offset, __btrfs_submit_bio_start, __btrfs_submit_bio_done); } mapit: return btrfs_map_bio(root, rw, bio, mirror_num, 0); } /* * given a list of ordered sums record them in the inode. This happens * at IO completion time based on sums calculated at bio submission time. */ static noinline int add_pending_csums(struct btrfs_trans_handle *trans, struct inode *inode, u64 file_offset, struct list_head *list) { struct btrfs_ordered_sum *sum; list_for_each_entry(sum, list, list) { btrfs_csum_file_blocks(trans, BTRFS_I(inode)->root->fs_info->csum_root, sum); } return 0; } int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end, struct extent_state **cached_state) { if ((end & (PAGE_CACHE_SIZE - 1)) == 0) WARN_ON(1); return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end, cached_state, GFP_NOFS); } /* see btrfs_writepage_start_hook for details on why this is required */ struct btrfs_writepage_fixup { struct page *page; struct btrfs_work work; }; static void btrfs_writepage_fixup_worker(struct btrfs_work *work) { struct btrfs_writepage_fixup *fixup; struct btrfs_ordered_extent *ordered; struct extent_state *cached_state = NULL; struct page *page; struct inode *inode; u64 page_start; u64 page_end; fixup = container_of(work, struct btrfs_writepage_fixup, work); page = fixup->page; again: lock_page(page); if (!page->mapping || !PageDirty(page) || !PageChecked(page)) { ClearPageChecked(page); goto out_page; } inode = page->mapping->host; page_start = page_offset(page); page_end = page_offset(page) + PAGE_CACHE_SIZE - 1; lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, 0, &cached_state, GFP_NOFS); /* already ordered? We're done */ if (PagePrivate2(page)) goto out; ordered = btrfs_lookup_ordered_extent(inode, page_start); if (ordered) { unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end, &cached_state, GFP_NOFS); unlock_page(page); btrfs_start_ordered_extent(inode, ordered, 1); goto again; } BUG(); btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state); ClearPageChecked(page); out: unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end, &cached_state, GFP_NOFS); out_page: unlock_page(page); page_cache_release(page); kfree(fixup); } /* * There are a few paths in the higher layers of the kernel that directly * set the page dirty bit without asking the filesystem if it is a * good idea. This causes problems because we want to make sure COW * properly happens and the data=ordered rules are followed. * * In our case any range that doesn't have the ORDERED bit set * hasn't been properly setup for IO. We kick off an async process * to fix it up. The async helper will wait for ordered extents, set * the delalloc bit and make it safe to write the page. */ static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end) { struct inode *inode = page->mapping->host; struct btrfs_writepage_fixup *fixup; struct btrfs_root *root = BTRFS_I(inode)->root; /* this page is properly in the ordered list */ if (TestClearPagePrivate2(page)) return 0; if (PageChecked(page)) return -EAGAIN; fixup = kzalloc(sizeof(*fixup), GFP_NOFS); if (!fixup) return -EAGAIN; SetPageChecked(page); page_cache_get(page); fixup->work.func = btrfs_writepage_fixup_worker; fixup->page = page; btrfs_queue_worker(&root->fs_info->fixup_workers, &fixup->work); return -EAGAIN; } static int insert_reserved_file_extent(struct btrfs_trans_handle *trans, struct inode *inode, u64 file_pos, u64 disk_bytenr, u64 disk_num_bytes, u64 num_bytes, u64 ram_bytes, u8 compression, u8 encryption, u16 other_encoding, int extent_type) { struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_file_extent_item *fi; struct btrfs_path *path; struct extent_buffer *leaf; struct btrfs_key ins; u64 hint; int ret; path = btrfs_alloc_path(); BUG_ON(!path); path->leave_spinning = 1; /* * we may be replacing one extent in the tree with another. * The new extent is pinned in the extent map, and we don't want * to drop it from the cache until it is completely in the btree. * * So, tell btrfs_drop_extents to leave this extent in the cache. * the caller is expected to unpin it and allow it to be merged * with the others. */ ret = btrfs_drop_extents(trans, inode, file_pos, file_pos + num_bytes, &hint, 0); BUG_ON(ret); ins.objectid = btrfs_ino(inode); ins.offset = file_pos; ins.type = BTRFS_EXTENT_DATA_KEY; ret = btrfs_insert_empty_item(trans, root, path, &ins, sizeof(*fi)); BUG_ON(ret); leaf = path->nodes[0]; fi = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); btrfs_set_file_extent_generation(leaf, fi, trans->transid); btrfs_set_file_extent_type(leaf, fi, extent_type); btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr); btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes); btrfs_set_file_extent_offset(leaf, fi, 0); btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes); btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes); btrfs_set_file_extent_compression(leaf, fi, compression); btrfs_set_file_extent_encryption(leaf, fi, encryption); btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding); btrfs_unlock_up_safe(path, 1); btrfs_set_lock_blocking(leaf); btrfs_mark_buffer_dirty(leaf); inode_add_bytes(inode, num_bytes); ins.objectid = disk_bytenr; ins.offset = disk_num_bytes; ins.type = BTRFS_EXTENT_ITEM_KEY; ret = btrfs_alloc_reserved_file_extent(trans, root, root->root_key.objectid, btrfs_ino(inode), file_pos, &ins); BUG_ON(ret); btrfs_free_path(path); return 0; } /* * helper function for btrfs_finish_ordered_io, this * just reads in some of the csum leaves to prime them into ram * before we start the transaction. It limits the amount of btree * reads required while inside the transaction. */ /* as ordered data IO finishes, this gets called so we can finish * an ordered extent if the range of bytes in the file it covers are * fully written. */ static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end) { struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_trans_handle *trans = NULL; struct btrfs_ordered_extent *ordered_extent = NULL; struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; struct extent_state *cached_state = NULL; int compress_type = 0; int ret; bool nolock; ret = btrfs_dec_test_ordered_pending(inode, &ordered_extent, start, end - start + 1); if (!ret) return 0; BUG_ON(!ordered_extent); nolock = btrfs_is_free_space_inode(root, inode); if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) { BUG_ON(!list_empty(&ordered_extent->list)); ret = btrfs_ordered_update_i_size(inode, 0, ordered_extent); if (!ret) { if (nolock) trans = btrfs_join_transaction_nolock(root); else trans = btrfs_join_transaction(root); BUG_ON(IS_ERR(trans)); trans->block_rsv = &root->fs_info->delalloc_block_rsv; ret = btrfs_update_inode(trans, root, inode); BUG_ON(ret); } goto out; } lock_extent_bits(io_tree, ordered_extent->file_offset, ordered_extent->file_offset + ordered_extent->len - 1, 0, &cached_state, GFP_NOFS); if (nolock) trans = btrfs_join_transaction_nolock(root); else trans = btrfs_join_transaction(root); BUG_ON(IS_ERR(trans)); trans->block_rsv = &root->fs_info->delalloc_block_rsv; if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags)) compress_type = ordered_extent->compress_type; if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) { BUG_ON(compress_type); ret = btrfs_mark_extent_written(trans, inode, ordered_extent->file_offset, ordered_extent->file_offset + ordered_extent->len); BUG_ON(ret); } else { BUG_ON(root == root->fs_info->tree_root); ret = insert_reserved_file_extent(trans, inode, ordered_extent->file_offset, ordered_extent->start, ordered_extent->disk_len, ordered_extent->len, ordered_extent->len, compress_type, 0, 0, BTRFS_FILE_EXTENT_REG); unpin_extent_cache(&BTRFS_I(inode)->extent_tree, ordered_extent->file_offset, ordered_extent->len); BUG_ON(ret); } unlock_extent_cached(io_tree, ordered_extent->file_offset, ordered_extent->file_offset + ordered_extent->len - 1, &cached_state, GFP_NOFS); add_pending_csums(trans, inode, ordered_extent->file_offset, &ordered_extent->list); ret = btrfs_ordered_update_i_size(inode, 0, ordered_extent); if (!ret) { ret = btrfs_update_inode(trans, root, inode); BUG_ON(ret); } ret = 0; out: if (nolock) { if (trans) btrfs_end_transaction_nolock(trans, root); } else { btrfs_delalloc_release_metadata(inode, ordered_extent->len); if (trans) btrfs_end_transaction(trans, root); } /* once for us */ btrfs_put_ordered_extent(ordered_extent); /* once for the tree */ btrfs_put_ordered_extent(ordered_extent); return 0; } static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end, struct extent_state *state, int uptodate) { trace_btrfs_writepage_end_io_hook(page, start, end, uptodate); ClearPagePrivate2(page); return btrfs_finish_ordered_io(page->mapping->host, start, end); } /* * When IO fails, either with EIO or csum verification fails, we * try other mirrors that might have a good copy of the data. This * io_failure_record is used to record state as we go through all the * mirrors. If another mirror has good data, the page is set up to date * and things continue. If a good mirror can't be found, the original * bio end_io callback is called to indicate things have failed. */ struct io_failure_record { struct page *page; u64 start; u64 len; u64 logical; unsigned long bio_flags; int last_mirror; }; static int btrfs_io_failed_hook(struct bio *failed_bio, struct page *page, u64 start, u64 end, struct extent_state *state) { struct io_failure_record *failrec = NULL; u64 private; struct extent_map *em; struct inode *inode = page->mapping->host; struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree; struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; struct bio *bio; int num_copies; int ret; int rw; u64 logical; ret = get_state_private(failure_tree, start, &private); if (ret) { failrec = kmalloc(sizeof(*failrec), GFP_NOFS); if (!failrec) return -ENOMEM; failrec->start = start; failrec->len = end - start + 1; failrec->last_mirror = 0; failrec->bio_flags = 0; read_lock(&em_tree->lock); em = lookup_extent_mapping(em_tree, start, failrec->len); if (em->start > start || em->start + em->len < start) { free_extent_map(em); em = NULL; } read_unlock(&em_tree->lock); if (IS_ERR_OR_NULL(em)) { kfree(failrec); return -EIO; } logical = start - em->start; logical = em->block_start + logical; if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) { logical = em->block_start; failrec->bio_flags = EXTENT_BIO_COMPRESSED; extent_set_compress_type(&failrec->bio_flags, em->compress_type); } failrec->logical = logical; free_extent_map(em); set_extent_bits(failure_tree, start, end, EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS); set_state_private(failure_tree, start, (u64)(unsigned long)failrec); } else { failrec = (struct io_failure_record *)(unsigned long)private; } num_copies = btrfs_num_copies( &BTRFS_I(inode)->root->fs_info->mapping_tree, failrec->logical, failrec->len); failrec->last_mirror++; if (!state) { spin_lock(&BTRFS_I(inode)->io_tree.lock); state = find_first_extent_bit_state(&BTRFS_I(inode)->io_tree, failrec->start, EXTENT_LOCKED); if (state && state->start != failrec->start) state = NULL; spin_unlock(&BTRFS_I(inode)->io_tree.lock); } if (!state || failrec->last_mirror > num_copies) { set_state_private(failure_tree, failrec->start, 0); clear_extent_bits(failure_tree, failrec->start, failrec->start + failrec->len - 1, EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS); kfree(failrec); return -EIO; } bio = bio_alloc(GFP_NOFS, 1); bio->bi_private = state; bio->bi_end_io = failed_bio->bi_end_io; bio->bi_sector = failrec->logical >> 9; bio->bi_bdev = failed_bio->bi_bdev; bio->bi_size = 0; bio_add_page(bio, page, failrec->len, start - page_offset(page)); if (failed_bio->bi_rw & REQ_WRITE) rw = WRITE; else rw = READ; ret = BTRFS_I(inode)->io_tree.ops->submit_bio_hook(inode, rw, bio, failrec->last_mirror, failrec->bio_flags, 0); return ret; } /* * each time an IO finishes, we do a fast check in the IO failure tree * to see if we need to process or clean up an io_failure_record */ static int btrfs_clean_io_failures(struct inode *inode, u64 start) { u64 private; u64 private_failure; struct io_failure_record *failure; int ret; private = 0; if (count_range_bits(&BTRFS_I(inode)->io_failure_tree, &private, (u64)-1, 1, EXTENT_DIRTY, 0)) { ret = get_state_private(&BTRFS_I(inode)->io_failure_tree, start, &private_failure); if (ret == 0) { failure = (struct io_failure_record *)(unsigned long) private_failure; set_state_private(&BTRFS_I(inode)->io_failure_tree, failure->start, 0); clear_extent_bits(&BTRFS_I(inode)->io_failure_tree, failure->start, failure->start + failure->len - 1, EXTENT_DIRTY | EXTENT_LOCKED, GFP_NOFS); kfree(failure); } } return 0; } /* * when reads are done, we need to check csums to verify the data is correct * if there's a match, we allow the bio to finish. If not, we go through * the io_failure_record routines to find good copies */ static int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end, struct extent_state *state) { size_t offset = start - ((u64)page->index << PAGE_CACHE_SHIFT); struct inode *inode = page->mapping->host; struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; char *kaddr; u64 private = ~(u32)0; int ret; struct btrfs_root *root = BTRFS_I(inode)->root; u32 csum = ~(u32)0; if (PageChecked(page)) { ClearPageChecked(page); goto good; } if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM) goto good; if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID && test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) { clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM, GFP_NOFS); return 0; } if (state && state->start == start) { private = state->private; ret = 0; } else { ret = get_state_private(io_tree, start, &private); } kaddr = kmap_atomic(page, KM_USER0); if (ret) goto zeroit; csum = btrfs_csum_data(root, kaddr + offset, csum, end - start + 1); btrfs_csum_final(csum, (char *)&csum); if (csum != private) goto zeroit; kunmap_atomic(kaddr, KM_USER0); good: /* if the io failure tree for this inode is non-empty, * check to see if we've recovered from a failed IO */ btrfs_clean_io_failures(inode, start); return 0; zeroit: printk_ratelimited(KERN_INFO "btrfs csum failed ino %llu off %llu csum %u " "private %llu\n", (unsigned long long)btrfs_ino(page->mapping->host), (unsigned long long)start, csum, (unsigned long long)private); memset(kaddr + offset, 1, end - start + 1); flush_dcache_page(page); kunmap_atomic(kaddr, KM_USER0); if (private == 0) return 0; return -EIO; } struct delayed_iput { struct list_head list; struct inode *inode; }; void btrfs_add_delayed_iput(struct inode *inode) { struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info; struct delayed_iput *delayed; if (atomic_add_unless(&inode->i_count, -1, 1)) return; delayed = kmalloc(sizeof(*delayed), GFP_NOFS | __GFP_NOFAIL); delayed->inode = inode; spin_lock(&fs_info->delayed_iput_lock); list_add_tail(&delayed->list, &fs_info->delayed_iputs); spin_unlock(&fs_info->delayed_iput_lock); } void btrfs_run_delayed_iputs(struct btrfs_root *root) { LIST_HEAD(list); struct btrfs_fs_info *fs_info = root->fs_info; struct delayed_iput *delayed; int empty; spin_lock(&fs_info->delayed_iput_lock); empty = list_empty(&fs_info->delayed_iputs); spin_unlock(&fs_info->delayed_iput_lock); if (empty) return; down_read(&root->fs_info->cleanup_work_sem); spin_lock(&fs_info->delayed_iput_lock); list_splice_init(&fs_info->delayed_iputs, &list); spin_unlock(&fs_info->delayed_iput_lock); while (!list_empty(&list)) { delayed = list_entry(list.next, struct delayed_iput, list); list_del(&delayed->list); iput(delayed->inode); kfree(delayed); } up_read(&root->fs_info->cleanup_work_sem); } /* * calculate extra metadata reservation when snapshotting a subvolume * contains orphan files. */ void btrfs_orphan_pre_snapshot(struct btrfs_trans_handle *trans, struct btrfs_pending_snapshot *pending, u64 *bytes_to_reserve) { struct btrfs_root *root; struct btrfs_block_rsv *block_rsv; u64 num_bytes; int index; root = pending->root; if (!root->orphan_block_rsv || list_empty(&root->orphan_list)) return; block_rsv = root->orphan_block_rsv; /* orphan block reservation for the snapshot */ num_bytes = block_rsv->size; /* * after the snapshot is created, COWing tree blocks may use more * space than it frees. So we should make sure there is enough * reserved space. */ index = trans->transid & 0x1; if (block_rsv->reserved + block_rsv->freed[index] < block_rsv->size) { num_bytes += block_rsv->size - (block_rsv->reserved + block_rsv->freed[index]); } *bytes_to_reserve += num_bytes; } void btrfs_orphan_post_snapshot(struct btrfs_trans_handle *trans, struct btrfs_pending_snapshot *pending) { struct btrfs_root *root = pending->root; struct btrfs_root *snap = pending->snap; struct btrfs_block_rsv *block_rsv; u64 num_bytes; int index; int ret; if (!root->orphan_block_rsv || list_empty(&root->orphan_list)) return; /* refill source subvolume's orphan block reservation */ block_rsv = root->orphan_block_rsv; index = trans->transid & 0x1; if (block_rsv->reserved + block_rsv->freed[index] < block_rsv->size) { num_bytes = block_rsv->size - (block_rsv->reserved + block_rsv->freed[index]); ret = btrfs_block_rsv_migrate(&pending->block_rsv, root->orphan_block_rsv, num_bytes); BUG_ON(ret); } /* setup orphan block reservation for the snapshot */ block_rsv = btrfs_alloc_block_rsv(snap); BUG_ON(!block_rsv); btrfs_add_durable_block_rsv(root->fs_info, block_rsv); snap->orphan_block_rsv = block_rsv; num_bytes = root->orphan_block_rsv->size; ret = btrfs_block_rsv_migrate(&pending->block_rsv, block_rsv, num_bytes); BUG_ON(ret); #if 0 /* insert orphan item for the snapshot */ WARN_ON(!root->orphan_item_inserted); ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root, snap->root_key.objectid); BUG_ON(ret); snap->orphan_item_inserted = 1; #endif } enum btrfs_orphan_cleanup_state { ORPHAN_CLEANUP_STARTED = 1, ORPHAN_CLEANUP_DONE = 2, }; /* * This is called in transaction commmit time. If there are no orphan * files in the subvolume, it removes orphan item and frees block_rsv * structure. */ void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans, struct btrfs_root *root) { int ret; if (!list_empty(&root->orphan_list) || root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) return; if (root->orphan_item_inserted && btrfs_root_refs(&root->root_item) > 0) { ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root, root->root_key.objectid); BUG_ON(ret); root->orphan_item_inserted = 0; } if (root->orphan_block_rsv) { WARN_ON(root->orphan_block_rsv->size > 0); btrfs_free_block_rsv(root, root->orphan_block_rsv); root->orphan_block_rsv = NULL; } } /* * This creates an orphan entry for the given inode in case something goes * wrong in the middle of an unlink/truncate. * * NOTE: caller of this function should reserve 5 units of metadata for * this function. */ int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode) { struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_block_rsv *block_rsv = NULL; int reserve = 0; int insert = 0; int ret; if (!root->orphan_block_rsv) { block_rsv = btrfs_alloc_block_rsv(root); BUG_ON(!block_rsv); } spin_lock(&root->orphan_lock); if (!root->orphan_block_rsv) { root->orphan_block_rsv = block_rsv; } else if (block_rsv) { btrfs_free_block_rsv(root, block_rsv); block_rsv = NULL; } if (list_empty(&BTRFS_I(inode)->i_orphan)) { list_add(&BTRFS_I(inode)->i_orphan, &root->orphan_list); #if 0 /* * For proper ENOSPC handling, we should do orphan * cleanup when mounting. But this introduces backward * compatibility issue. */ if (!xchg(&root->orphan_item_inserted, 1)) insert = 2; else insert = 1; #endif insert = 1; } if (!BTRFS_I(inode)->orphan_meta_reserved) { BTRFS_I(inode)->orphan_meta_reserved = 1; reserve = 1; } spin_unlock(&root->orphan_lock); if (block_rsv) btrfs_add_durable_block_rsv(root->fs_info, block_rsv); /* grab metadata reservation from transaction handle */ if (reserve) { ret = btrfs_orphan_reserve_metadata(trans, inode); BUG_ON(ret); } /* insert an orphan item to track this unlinked/truncated file */ if (insert >= 1) { ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode)); BUG_ON(ret); } /* insert an orphan item to track subvolume contains orphan files */ if (insert >= 2) { ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root, root->root_key.objectid); BUG_ON(ret); } return 0; } /* * We have done the truncate/delete so we can go ahead and remove the orphan * item for this particular inode. */ int btrfs_orphan_del(struct btrfs_trans_handle *trans, struct inode *inode) { struct btrfs_root *root = BTRFS_I(inode)->root; int delete_item = 0; int release_rsv = 0; int ret = 0; spin_lock(&root->orphan_lock); if (!list_empty(&BTRFS_I(inode)->i_orphan)) { list_del_init(&BTRFS_I(inode)->i_orphan); delete_item = 1; } if (BTRFS_I(inode)->orphan_meta_reserved) { BTRFS_I(inode)->orphan_meta_reserved = 0; release_rsv = 1; } spin_unlock(&root->orphan_lock); if (trans && delete_item) { ret = btrfs_del_orphan_item(trans, root, btrfs_ino(inode)); BUG_ON(ret); } if (release_rsv) btrfs_orphan_release_metadata(inode); return 0; } /* * this cleans up any orphans that may be left on the list from the last use * of this root. */ int btrfs_orphan_cleanup(struct btrfs_root *root) { struct btrfs_path *path; struct extent_buffer *leaf; struct btrfs_key key, found_key; struct btrfs_trans_handle *trans; struct inode *inode; int ret = 0, nr_unlink = 0, nr_truncate = 0; if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED)) return 0; path = btrfs_alloc_path(); if (!path) { ret = -ENOMEM; goto out; } path->reada = -1; key.objectid = BTRFS_ORPHAN_OBJECTID; btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY); key.offset = (u64)-1; while (1) { ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) goto out; /* * if ret == 0 means we found what we were searching for, which * is weird, but possible, so only screw with path if we didn't * find the key and see if we have stuff that matches */ if (ret > 0) { ret = 0; if (path->slots[0] == 0) break; path->slots[0]--; } /* pull out the item */ leaf = path->nodes[0]; btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); /* make sure the item matches what we want */ if (found_key.objectid != BTRFS_ORPHAN_OBJECTID) break; if (btrfs_key_type(&found_key) != BTRFS_ORPHAN_ITEM_KEY) break; /* release the path since we're done with it */ btrfs_release_path(path); /* * this is where we are basically btrfs_lookup, without the * crossing root thing. we store the inode number in the * offset of the orphan item. */ found_key.objectid = found_key.offset; found_key.type = BTRFS_INODE_ITEM_KEY; found_key.offset = 0; inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL); if (IS_ERR(inode)) { ret = PTR_ERR(inode); goto out; } /* * add this inode to the orphan list so btrfs_orphan_del does * the proper thing when we hit it */ spin_lock(&root->orphan_lock); list_add(&BTRFS_I(inode)->i_orphan, &root->orphan_list); spin_unlock(&root->orphan_lock); /* * if this is a bad inode, means we actually succeeded in * removing the inode, but not the orphan record, which means * we need to manually delete the orphan since iput will just * do a destroy_inode */ if (is_bad_inode(inode)) { trans = btrfs_start_transaction(root, 0); if (IS_ERR(trans)) { ret = PTR_ERR(trans); goto out; } btrfs_orphan_del(trans, inode); btrfs_end_transaction(trans, root); iput(inode); continue; } /* if we have links, this was a truncate, lets do that */ if (inode->i_nlink) { if (!S_ISREG(inode->i_mode)) { WARN_ON(1); iput(inode); continue; } nr_truncate++; ret = btrfs_truncate(inode); } else { nr_unlink++; } /* this will do delete_inode and everything for us */ iput(inode); if (ret) goto out; } root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE; if (root->orphan_block_rsv) btrfs_block_rsv_release(root, root->orphan_block_rsv, (u64)-1); if (root->orphan_block_rsv || root->orphan_item_inserted) { trans = btrfs_join_transaction(root); if (!IS_ERR(trans)) btrfs_end_transaction(trans, root); } if (nr_unlink) printk(KERN_INFO "btrfs: unlinked %d orphans\n", nr_unlink); if (nr_truncate) printk(KERN_INFO "btrfs: truncated %d orphans\n", nr_truncate); out: if (ret) printk(KERN_CRIT "btrfs: could not do orphan cleanup %d\n", ret); btrfs_free_path(path); return ret; } /* * very simple check to peek ahead in the leaf looking for xattrs. If we * don't find any xattrs, we know there can't be any acls. * * slot is the slot the inode is in, objectid is the objectid of the inode */ static noinline int acls_after_inode_item(struct extent_buffer *leaf, int slot, u64 objectid) { u32 nritems = btrfs_header_nritems(leaf); struct btrfs_key found_key; int scanned = 0; slot++; while (slot < nritems) { btrfs_item_key_to_cpu(leaf, &found_key, slot); /* we found a different objectid, there must not be acls */ if (found_key.objectid != objectid) return 0; /* we found an xattr, assume we've got an acl */ if (found_key.type == BTRFS_XATTR_ITEM_KEY) return 1; /* * we found a key greater than an xattr key, there can't * be any acls later on */ if (found_key.type > BTRFS_XATTR_ITEM_KEY) return 0; slot++; scanned++; /* * it goes inode, inode backrefs, xattrs, extents, * so if there are a ton of hard links to an inode there can * be a lot of backrefs. Don't waste time searching too hard, * this is just an optimization */ if (scanned >= 8) break; } /* we hit the end of the leaf before we found an xattr or * something larger than an xattr. We have to assume the inode * has acls */ return 1; } /* * read an inode from the btree into the in-memory inode */ static void btrfs_read_locked_inode(struct inode *inode) { struct btrfs_path *path; struct extent_buffer *leaf; struct btrfs_inode_item *inode_item; struct btrfs_timespec *tspec; struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_key location; int maybe_acls; u32 rdev; int ret; bool filled = false; ret = btrfs_fill_inode(inode, &rdev); if (!ret) filled = true; path = btrfs_alloc_path(); BUG_ON(!path); path->leave_spinning = 1; memcpy(&location, &BTRFS_I(inode)->location, sizeof(location)); ret = btrfs_lookup_inode(NULL, root, path, &location, 0); if (ret) goto make_bad; leaf = path->nodes[0]; if (filled) goto cache_acl; inode_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item); inode->i_mode = btrfs_inode_mode(leaf, inode_item); inode->i_nlink = btrfs_inode_nlink(leaf, inode_item); inode->i_uid = btrfs_inode_uid(leaf, inode_item); inode->i_gid = btrfs_inode_gid(leaf, inode_item); btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item)); tspec = btrfs_inode_atime(inode_item); inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec); inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec); tspec = btrfs_inode_mtime(inode_item); inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec); inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec); tspec = btrfs_inode_ctime(inode_item); inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec); inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec); inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item)); BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item); BTRFS_I(inode)->sequence = btrfs_inode_sequence(leaf, inode_item); inode->i_generation = BTRFS_I(inode)->generation; inode->i_rdev = 0; rdev = btrfs_inode_rdev(leaf, inode_item); BTRFS_I(inode)->index_cnt = (u64)-1; BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item); cache_acl: /* * try to precache a NULL acl entry for files that don't have * any xattrs or acls */ maybe_acls = acls_after_inode_item(leaf, path->slots[0], btrfs_ino(inode)); if (!maybe_acls) cache_no_acl(inode); btrfs_free_path(path); switch (inode->i_mode & S_IFMT) { case S_IFREG: inode->i_mapping->a_ops = &btrfs_aops; inode->i_mapping->backing_dev_info = &root->fs_info->bdi; BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; inode->i_fop = &btrfs_file_operations; inode->i_op = &btrfs_file_inode_operations; break; case S_IFDIR: inode->i_fop = &btrfs_dir_file_operations; if (root == root->fs_info->tree_root) inode->i_op = &btrfs_dir_ro_inode_operations; else inode->i_op = &btrfs_dir_inode_operations; break; case S_IFLNK: inode->i_op = &btrfs_symlink_inode_operations; inode->i_mapping->a_ops = &btrfs_symlink_aops; inode->i_mapping->backing_dev_info = &root->fs_info->bdi; break; default: inode->i_op = &btrfs_special_inode_operations; init_special_inode(inode, inode->i_mode, rdev); break; } btrfs_update_iflags(inode); return; make_bad: btrfs_free_path(path); make_bad_inode(inode); } /* * given a leaf and an inode, copy the inode fields into the leaf */ static void fill_inode_item(struct btrfs_trans_handle *trans, struct extent_buffer *leaf, struct btrfs_inode_item *item, struct inode *inode) { btrfs_set_inode_uid(leaf, item, inode->i_uid); btrfs_set_inode_gid(leaf, item, inode->i_gid); btrfs_set_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size); btrfs_set_inode_mode(leaf, item, inode->i_mode); btrfs_set_inode_nlink(leaf, item, inode->i_nlink); btrfs_set_timespec_sec(leaf, btrfs_inode_atime(item), inode->i_atime.tv_sec); btrfs_set_timespec_nsec(leaf, btrfs_inode_atime(item), inode->i_atime.tv_nsec); btrfs_set_timespec_sec(leaf, btrfs_inode_mtime(item), inode->i_mtime.tv_sec); btrfs_set_timespec_nsec(leaf, btrfs_inode_mtime(item), inode->i_mtime.tv_nsec); btrfs_set_timespec_sec(leaf, btrfs_inode_ctime(item), inode->i_ctime.tv_sec); btrfs_set_timespec_nsec(leaf, btrfs_inode_ctime(item), inode->i_ctime.tv_nsec); btrfs_set_inode_nbytes(leaf, item, inode_get_bytes(inode)); btrfs_set_inode_generation(leaf, item, BTRFS_I(inode)->generation); btrfs_set_inode_sequence(leaf, item, BTRFS_I(inode)->sequence); btrfs_set_inode_transid(leaf, item, trans->transid); btrfs_set_inode_rdev(leaf, item, inode->i_rdev); btrfs_set_inode_flags(leaf, item, BTRFS_I(inode)->flags); btrfs_set_inode_block_group(leaf, item, 0); } /* * copy everything in the in-memory inode into the btree. */ noinline int btrfs_update_inode(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct inode *inode) { struct btrfs_inode_item *inode_item; struct btrfs_path *path; struct extent_buffer *leaf; int ret; /* * If the inode is a free space inode, we can deadlock during commit * if we put it into the delayed code. * * The data relocation inode should also be directly updated * without delay */ if (!btrfs_is_free_space_inode(root, inode) && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID) { ret = btrfs_delayed_update_inode(trans, root, inode); if (!ret) btrfs_set_inode_last_trans(trans, inode); return ret; } path = btrfs_alloc_path(); if (!path) return -ENOMEM; path->leave_spinning = 1; ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location, 1); if (ret) { if (ret > 0) ret = -ENOENT; goto failed; } btrfs_unlock_up_safe(path, 1); leaf = path->nodes[0]; inode_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item); fill_inode_item(trans, leaf, inode_item, inode); btrfs_mark_buffer_dirty(leaf); btrfs_set_inode_last_trans(trans, inode); ret = 0; failed: btrfs_free_path(path); return ret; } /* * unlink helper that gets used here in inode.c and in the tree logging * recovery code. It remove a link in a directory with a given name, and * also drops the back refs in the inode to the directory */ static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct inode *dir, struct inode *inode, const char *name, int name_len) { struct btrfs_path *path; int ret = 0; struct extent_buffer *leaf; struct btrfs_dir_item *di; struct btrfs_key key; u64 index; u64 ino = btrfs_ino(inode); u64 dir_ino = btrfs_ino(dir); path = btrfs_alloc_path(); if (!path) { ret = -ENOMEM; goto out; } path->leave_spinning = 1; di = btrfs_lookup_dir_item(trans, root, path, dir_ino, name, name_len, -1); if (IS_ERR(di)) { ret = PTR_ERR(di); goto err; } if (!di) { ret = -ENOENT; goto err; } leaf = path->nodes[0]; btrfs_dir_item_key_to_cpu(leaf, di, &key); ret = btrfs_delete_one_dir_name(trans, root, path, di); if (ret) goto err; btrfs_release_path(path); ret = btrfs_del_inode_ref(trans, root, name, name_len, ino, dir_ino, &index); if (ret) { printk(KERN_INFO "btrfs failed to delete reference to %.*s, " "inode %llu parent %llu\n", name_len, name, (unsigned long long)ino, (unsigned long long)dir_ino); goto err; } ret = btrfs_delete_delayed_dir_index(trans, root, dir, index); if (ret) goto err; ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len, inode, dir_ino); BUG_ON(ret != 0 && ret != -ENOENT); ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len, dir, index); if (ret == -ENOENT) ret = 0; err: btrfs_free_path(path); if (ret) goto out; btrfs_i_size_write(dir, dir->i_size - name_len * 2); inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME; btrfs_update_inode(trans, root, dir); out: return ret; } int btrfs_unlink_inode(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct inode *dir, struct inode *inode, const char *name, int name_len) { int ret; ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len); if (!ret) { btrfs_drop_nlink(inode); ret = btrfs_update_inode(trans, root, inode); } return ret; } /* helper to check if there is any shared block in the path */ static int check_path_shared(struct btrfs_root *root, struct btrfs_path *path) { struct extent_buffer *eb; int level; u64 refs = 1; for (level = 0; level < BTRFS_MAX_LEVEL; level++) { int ret; if (!path->nodes[level]) break; eb = path->nodes[level]; if (!btrfs_block_can_be_shared(root, eb)) continue; ret = btrfs_lookup_extent_info(NULL, root, eb->start, eb->len, &refs, NULL); if (refs > 1) return 1; } return 0; } /* * helper to start transaction for unlink and rmdir. * * unlink and rmdir are special in btrfs, they do not always free space. * so in enospc case, we should make sure they will free space before * allowing them to use the global metadata reservation. */ static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir, struct dentry *dentry) { struct btrfs_trans_handle *trans; struct btrfs_root *root = BTRFS_I(dir)->root; struct btrfs_path *path; struct btrfs_inode_ref *ref; struct btrfs_dir_item *di; struct inode *inode = dentry->d_inode; u64 index; int check_link = 1; int err = -ENOSPC; int ret; u64 ino = btrfs_ino(inode); u64 dir_ino = btrfs_ino(dir); trans = btrfs_start_transaction(root, 10); if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC) return trans; if (ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) return ERR_PTR(-ENOSPC); /* check if there is someone else holds reference */ if (S_ISDIR(inode->i_mode) && atomic_read(&inode->i_count) > 1) return ERR_PTR(-ENOSPC); if (atomic_read(&inode->i_count) > 2) return ERR_PTR(-ENOSPC); if (xchg(&root->fs_info->enospc_unlink, 1)) return ERR_PTR(-ENOSPC); path = btrfs_alloc_path(); if (!path) { root->fs_info->enospc_unlink = 0; return ERR_PTR(-ENOMEM); } trans = btrfs_start_transaction(root, 0); if (IS_ERR(trans)) { btrfs_free_path(path); root->fs_info->enospc_unlink = 0; return trans; } path->skip_locking = 1; path->search_commit_root = 1; ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(dir)->location, 0); if (ret < 0) { err = ret; goto out; } if (ret == 0) { if (check_path_shared(root, path)) goto out; } else { check_link = 0; } btrfs_release_path(path); ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location, 0); if (ret < 0) { err = ret; goto out; } if (ret == 0) { if (check_path_shared(root, path)) goto out; } else { check_link = 0; } btrfs_release_path(path); if (ret == 0 && S_ISREG(inode->i_mode)) { ret = btrfs_lookup_file_extent(trans, root, path, ino, (u64)-1, 0); if (ret < 0) { err = ret; goto out; } BUG_ON(ret == 0); if (check_path_shared(root, path)) goto out; btrfs_release_path(path); } if (!check_link) { err = 0; goto out; } di = btrfs_lookup_dir_item(trans, root, path, dir_ino, dentry->d_name.name, dentry->d_name.len, 0); if (IS_ERR(di)) { err = PTR_ERR(di); goto out; } if (di) { if (check_path_shared(root, path)) goto out; } else { err = 0; goto out; } btrfs_release_path(path); ref = btrfs_lookup_inode_ref(trans, root, path, dentry->d_name.name, dentry->d_name.len, ino, dir_ino, 0); if (IS_ERR(ref)) { err = PTR_ERR(ref); goto out; } BUG_ON(!ref); if (check_path_shared(root, path)) goto out; index = btrfs_inode_ref_index(path->nodes[0], ref); btrfs_release_path(path); /* * This is a commit root search, if we can lookup inode item and other * relative items in the commit root, it means the transaction of * dir/file creation has been committed, and the dir index item that we * delay to insert has also been inserted into the commit root. So * we needn't worry about the delayed insertion of the dir index item * here. */ di = btrfs_lookup_dir_index_item(trans, root, path, dir_ino, index, dentry->d_name.name, dentry->d_name.len, 0); if (IS_ERR(di)) { err = PTR_ERR(di); goto out; } BUG_ON(ret == -ENOENT); if (check_path_shared(root, path)) goto out; err = 0; out: btrfs_free_path(path); if (err) { btrfs_end_transaction(trans, root); root->fs_info->enospc_unlink = 0; return ERR_PTR(err); } trans->block_rsv = &root->fs_info->global_block_rsv; return trans; } static void __unlink_end_trans(struct btrfs_trans_handle *trans, struct btrfs_root *root) { if (trans->block_rsv == &root->fs_info->global_block_rsv) { BUG_ON(!root->fs_info->enospc_unlink); root->fs_info->enospc_unlink = 0; } btrfs_end_transaction_throttle(trans, root); } static int btrfs_unlink(struct inode *dir, struct dentry *dentry) { struct btrfs_root *root = BTRFS_I(dir)->root; struct btrfs_trans_handle *trans; struct inode *inode = dentry->d_inode; int ret; unsigned long nr = 0; trans = __unlink_start_trans(dir, dentry); if (IS_ERR(trans)) return PTR_ERR(trans); btrfs_record_unlink_dir(trans, dir, dentry->d_inode, 0); ret = btrfs_unlink_inode(trans, root, dir, dentry->d_inode, dentry->d_name.name, dentry->d_name.len); BUG_ON(ret); if (inode->i_nlink == 0) { ret = btrfs_orphan_add(trans, inode); BUG_ON(ret); } nr = trans->blocks_used; __unlink_end_trans(trans, root); btrfs_btree_balance_dirty(root, nr); return ret; } int btrfs_unlink_subvol(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct inode *dir, u64 objectid, const char *name, int name_len) { struct btrfs_path *path; struct extent_buffer *leaf; struct btrfs_dir_item *di; struct btrfs_key key; u64 index; int ret; u64 dir_ino = btrfs_ino(dir); path = btrfs_alloc_path(); if (!path) return -ENOMEM; di = btrfs_lookup_dir_item(trans, root, path, dir_ino, name, name_len, -1); BUG_ON(IS_ERR_OR_NULL(di)); leaf = path->nodes[0]; btrfs_dir_item_key_to_cpu(leaf, di, &key); WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid); ret = btrfs_delete_one_dir_name(trans, root, path, di); BUG_ON(ret); btrfs_release_path(path); ret = btrfs_del_root_ref(trans, root->fs_info->tree_root, objectid, root->root_key.objectid, dir_ino, &index, name, name_len); if (ret < 0) { BUG_ON(ret != -ENOENT); di = btrfs_search_dir_index_item(root, path, dir_ino, name, name_len); BUG_ON(IS_ERR_OR_NULL(di)); leaf = path->nodes[0]; btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); btrfs_release_path(path); index = key.offset; } btrfs_release_path(path); ret = btrfs_delete_delayed_dir_index(trans, root, dir, index); BUG_ON(ret); btrfs_i_size_write(dir, dir->i_size - name_len * 2); dir->i_mtime = dir->i_ctime = CURRENT_TIME; ret = btrfs_update_inode(trans, root, dir); BUG_ON(ret); btrfs_free_path(path); return 0; } static int btrfs_rmdir(struct inode *dir, struct dentry *dentry) { struct inode *inode = dentry->d_inode; int err = 0; struct btrfs_root *root = BTRFS_I(dir)->root; struct btrfs_trans_handle *trans; unsigned long nr = 0; if (inode->i_size > BTRFS_EMPTY_DIR_SIZE || btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID) return -ENOTEMPTY; trans = __unlink_start_trans(dir, dentry); if (IS_ERR(trans)) return PTR_ERR(trans); if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) { err = btrfs_unlink_subvol(trans, root, dir, BTRFS_I(inode)->location.objectid, dentry->d_name.name, dentry->d_name.len); goto out; } err = btrfs_orphan_add(trans, inode); if (err) goto out; /* now the directory is empty */ err = btrfs_unlink_inode(trans, root, dir, dentry->d_inode, dentry->d_name.name, dentry->d_name.len); if (!err) btrfs_i_size_write(inode, 0); out: nr = trans->blocks_used; __unlink_end_trans(trans, root); btrfs_btree_balance_dirty(root, nr); return err; } /* * this can truncate away extent items, csum items and directory items. * It starts at a high offset and removes keys until it can't find * any higher than new_size * * csum items that cross the new i_size are truncated to the new size * as well. * * min_type is the minimum key type to truncate down to. If set to 0, this * will kill all the items on this inode, including the INODE_ITEM_KEY. */ int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct inode *inode, u64 new_size, u32 min_type) { struct btrfs_path *path; struct extent_buffer *leaf; struct btrfs_file_extent_item *fi; struct btrfs_key key; struct btrfs_key found_key; u64 extent_start = 0; u64 extent_num_bytes = 0; u64 extent_offset = 0; u64 item_end = 0; u64 mask = root->sectorsize - 1; u32 found_type = (u8)-1; int found_extent; int del_item; int pending_del_nr = 0; int pending_del_slot = 0; int extent_type = -1; int encoding; int ret; int err = 0; u64 ino = btrfs_ino(inode); BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY); if (root->ref_cows || root == root->fs_info->tree_root) btrfs_drop_extent_cache(inode, new_size & (~mask), (u64)-1, 0); /* * This function is also used to drop the items in the log tree before * we relog the inode, so if root != BTRFS_I(inode)->root, it means * it is used to drop the loged items. So we shouldn't kill the delayed * items. */ if (min_type == 0 && root == BTRFS_I(inode)->root) btrfs_kill_delayed_inode_items(inode); path = btrfs_alloc_path(); BUG_ON(!path); path->reada = -1; key.objectid = ino; key.offset = (u64)-1; key.type = (u8)-1; search_again: path->leave_spinning = 1; ret = btrfs_search_slot(trans, root, &key, path, -1, 1); if (ret < 0) { err = ret; goto out; } if (ret > 0) { /* there are no items in the tree for us to truncate, we're * done */ if (path->slots[0] == 0) goto out; path->slots[0]--; } while (1) { fi = NULL; leaf = path->nodes[0]; btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); found_type = btrfs_key_type(&found_key); encoding = 0; if (found_key.objectid != ino) break; if (found_type < min_type) break; item_end = found_key.offset; if (found_type == BTRFS_EXTENT_DATA_KEY) { fi = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); extent_type = btrfs_file_extent_type(leaf, fi); encoding = btrfs_file_extent_compression(leaf, fi); encoding |= btrfs_file_extent_encryption(leaf, fi); encoding |= btrfs_file_extent_other_encoding(leaf, fi); if (extent_type != BTRFS_FILE_EXTENT_INLINE) { item_end += btrfs_file_extent_num_bytes(leaf, fi); } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { item_end += btrfs_file_extent_inline_len(leaf, fi); } item_end--; } if (found_type > min_type) { del_item = 1; } else { if (item_end < new_size) break; if (found_key.offset >= new_size) del_item = 1; else del_item = 0; } found_extent = 0; /* FIXME, shrink the extent if the ref count is only 1 */ if (found_type != BTRFS_EXTENT_DATA_KEY) goto delete; if (extent_type != BTRFS_FILE_EXTENT_INLINE) { u64 num_dec; extent_start = btrfs_file_extent_disk_bytenr(leaf, fi); if (!del_item && !encoding) { u64 orig_num_bytes = btrfs_file_extent_num_bytes(leaf, fi); extent_num_bytes = new_size - found_key.offset + root->sectorsize - 1; extent_num_bytes = extent_num_bytes & ~((u64)root->sectorsize - 1); btrfs_set_file_extent_num_bytes(leaf, fi, extent_num_bytes); num_dec = (orig_num_bytes - extent_num_bytes); if (root->ref_cows && extent_start != 0) inode_sub_bytes(inode, num_dec); btrfs_mark_buffer_dirty(leaf); } else { extent_num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi); extent_offset = found_key.offset - btrfs_file_extent_offset(leaf, fi); /* FIXME blocksize != 4096 */ num_dec = btrfs_file_extent_num_bytes(leaf, fi); if (extent_start != 0) { found_extent = 1; if (root->ref_cows) inode_sub_bytes(inode, num_dec); } } } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { /* * we can't truncate inline items that have had * special encodings */ if (!del_item && btrfs_file_extent_compression(leaf, fi) == 0 && btrfs_file_extent_encryption(leaf, fi) == 0 && btrfs_file_extent_other_encoding(leaf, fi) == 0) { u32 size = new_size - found_key.offset; if (root->ref_cows) { inode_sub_bytes(inode, item_end + 1 - new_size); } size = btrfs_file_extent_calc_inline_size(size); ret = btrfs_truncate_item(trans, root, path, size, 1); } else if (root->ref_cows) { inode_sub_bytes(inode, item_end + 1 - found_key.offset); } } delete: if (del_item) { if (!pending_del_nr) { /* no pending yet, add ourselves */ pending_del_slot = path->slots[0]; pending_del_nr = 1; } else if (pending_del_nr && path->slots[0] + 1 == pending_del_slot) { /* hop on the pending chunk */ pending_del_nr++; pending_del_slot = path->slots[0]; } else { BUG(); } } else { break; } if (found_extent && (root->ref_cows || root == root->fs_info->tree_root)) { btrfs_set_path_blocking(path); ret = btrfs_free_extent(trans, root, extent_start, extent_num_bytes, 0, btrfs_header_owner(leaf), ino, extent_offset); BUG_ON(ret); } if (found_type == BTRFS_INODE_ITEM_KEY) break; if (path->slots[0] == 0 || path->slots[0] != pending_del_slot) { if (root->ref_cows && BTRFS_I(inode)->location.objectid != BTRFS_FREE_INO_OBJECTID) { err = -EAGAIN; goto out; } if (pending_del_nr) { ret = btrfs_del_items(trans, root, path, pending_del_slot, pending_del_nr); BUG_ON(ret); pending_del_nr = 0; } btrfs_release_path(path); goto search_again; } else { path->slots[0]--; } } out: if (pending_del_nr) { ret = btrfs_del_items(trans, root, path, pending_del_slot, pending_del_nr); BUG_ON(ret); } btrfs_free_path(path); return err; } /* * taken from block_truncate_page, but does cow as it zeros out * any bytes left in the last page in the file. */ static int btrfs_truncate_page(struct address_space *mapping, loff_t from) { struct inode *inode = mapping->host; struct btrfs_root *root = BTRFS_I(inode)->root; struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; struct btrfs_ordered_extent *ordered; struct extent_state *cached_state = NULL; char *kaddr; u32 blocksize = root->sectorsize; pgoff_t index = from >> PAGE_CACHE_SHIFT; unsigned offset = from & (PAGE_CACHE_SIZE-1); struct page *page; int ret = 0; u64 page_start; u64 page_end; if ((offset & (blocksize - 1)) == 0) goto out; ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE); if (ret) goto out; ret = -ENOMEM; again: page = find_or_create_page(mapping, index, GFP_NOFS); if (!page) { btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE); goto out; } page_start = page_offset(page); page_end = page_start + PAGE_CACHE_SIZE - 1; if (!PageUptodate(page)) { ret = btrfs_readpage(NULL, page); lock_page(page); if (page->mapping != mapping) { unlock_page(page); page_cache_release(page); goto again; } if (!PageUptodate(page)) { ret = -EIO; goto out_unlock; } } wait_on_page_writeback(page); lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state, GFP_NOFS); set_page_extent_mapped(page); ordered = btrfs_lookup_ordered_extent(inode, page_start); if (ordered) { unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS); unlock_page(page); page_cache_release(page); btrfs_start_ordered_extent(inode, ordered, 1); btrfs_put_ordered_extent(ordered); goto again; } clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end, EXTENT_DIRTY | EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING, 0, 0, &cached_state, GFP_NOFS); ret = btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state); if (ret) { unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS); goto out_unlock; } ret = 0; if (offset != PAGE_CACHE_SIZE) { kaddr = kmap(page); memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset); flush_dcache_page(page); kunmap(page); } ClearPageChecked(page); set_page_dirty(page); unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS); out_unlock: if (ret) btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE); unlock_page(page); page_cache_release(page); out: return ret; } /* * This function puts in dummy file extents for the area we're creating a hole * for. So if we are truncating this file to a larger size we need to insert * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for * the range between oldsize and size */ int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size) { struct btrfs_trans_handle *trans; struct btrfs_root *root = BTRFS_I(inode)->root; struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; struct extent_map *em = NULL; struct extent_state *cached_state = NULL; u64 mask = root->sectorsize - 1; u64 hole_start = (oldsize + mask) & ~mask; u64 block_end = (size + mask) & ~mask; u64 last_byte; u64 cur_offset; u64 hole_size; int err = 0; if (size <= hole_start) return 0; while (1) { struct btrfs_ordered_extent *ordered; btrfs_wait_ordered_range(inode, hole_start, block_end - hole_start); lock_extent_bits(io_tree, hole_start, block_end - 1, 0, &cached_state, GFP_NOFS); ordered = btrfs_lookup_ordered_extent(inode, hole_start); if (!ordered) break; unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state, GFP_NOFS); btrfs_put_ordered_extent(ordered); } cur_offset = hole_start; while (1) { em = btrfs_get_extent(inode, NULL, 0, cur_offset, block_end - cur_offset, 0); BUG_ON(IS_ERR_OR_NULL(em)); last_byte = min(extent_map_end(em), block_end); last_byte = (last_byte + mask) & ~mask; if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) { u64 hint_byte = 0; hole_size = last_byte - cur_offset; trans = btrfs_start_transaction(root, 2); if (IS_ERR(trans)) { err = PTR_ERR(trans); break; } err = btrfs_drop_extents(trans, inode, cur_offset, cur_offset + hole_size, &hint_byte, 1); if (err) break; err = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), cur_offset, 0, 0, hole_size, 0, hole_size, 0, 0, 0); if (err) break; btrfs_drop_extent_cache(inode, hole_start, last_byte - 1, 0); btrfs_end_transaction(trans, root); } free_extent_map(em); em = NULL; cur_offset = last_byte; if (cur_offset >= block_end) break; } free_extent_map(em); unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state, GFP_NOFS); return err; } static int btrfs_setsize(struct inode *inode, loff_t newsize) { loff_t oldsize = i_size_read(inode); int ret; if (newsize == oldsize) return 0; if (newsize > oldsize) { i_size_write(inode, newsize); btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL); truncate_pagecache(inode, oldsize, newsize); ret = btrfs_cont_expand(inode, oldsize, newsize); if (ret) { btrfs_setsize(inode, oldsize); return ret; } mark_inode_dirty(inode); } else { /* * We're truncating a file that used to have good data down to * zero. Make sure it gets into the ordered flush list so that * any new writes get down to disk quickly. */ if (newsize == 0) BTRFS_I(inode)->ordered_data_close = 1; /* we don't support swapfiles, so vmtruncate shouldn't fail */ truncate_setsize(inode, newsize); ret = btrfs_truncate(inode); } return ret; } static int btrfs_setattr(struct dentry *dentry, struct iattr *attr) { struct inode *inode = dentry->d_inode; struct btrfs_root *root = BTRFS_I(inode)->root; int err; if (btrfs_root_readonly(root)) return -EROFS; err = inode_change_ok(inode, attr); if (err) return err; if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) { err = btrfs_setsize(inode, attr->ia_size); if (err) return err; } if (attr->ia_valid) { setattr_copy(inode, attr); mark_inode_dirty(inode); if (attr->ia_valid & ATTR_MODE) err = btrfs_acl_chmod(inode); } return err; } void btrfs_evict_inode(struct inode *inode) { struct btrfs_trans_handle *trans; struct btrfs_root *root = BTRFS_I(inode)->root; unsigned long nr; int ret; trace_btrfs_inode_evict(inode); truncate_inode_pages(&inode->i_data, 0); if (inode->i_nlink && (btrfs_root_refs(&root->root_item) != 0 || btrfs_is_free_space_inode(root, inode))) goto no_delete; if (is_bad_inode(inode)) { btrfs_orphan_del(NULL, inode); goto no_delete; } /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */ btrfs_wait_ordered_range(inode, 0, (u64)-1); if (root->fs_info->log_root_recovering) { BUG_ON(!list_empty(&BTRFS_I(inode)->i_orphan)); goto no_delete; } if (inode->i_nlink > 0) { BUG_ON(btrfs_root_refs(&root->root_item) != 0); goto no_delete; } btrfs_i_size_write(inode, 0); while (1) { trans = btrfs_join_transaction(root); BUG_ON(IS_ERR(trans)); trans->block_rsv = root->orphan_block_rsv; ret = btrfs_block_rsv_check(trans, root, root->orphan_block_rsv, 0, 5); if (ret) { BUG_ON(ret != -EAGAIN); ret = btrfs_commit_transaction(trans, root); BUG_ON(ret); continue; } ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0); if (ret != -EAGAIN) break; nr = trans->blocks_used; btrfs_end_transaction(trans, root); trans = NULL; btrfs_btree_balance_dirty(root, nr); } if (ret == 0) { ret = btrfs_orphan_del(trans, inode); BUG_ON(ret); } if (!(root == root->fs_info->tree_root || root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)) btrfs_return_ino(root, btrfs_ino(inode)); nr = trans->blocks_used; btrfs_end_transaction(trans, root); btrfs_btree_balance_dirty(root, nr); no_delete: end_writeback(inode); return; } /* * this returns the key found in the dir entry in the location pointer. * If no dir entries were found, location->objectid is 0. */ static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry, struct btrfs_key *location) { const char *name = dentry->d_name.name; int namelen = dentry->d_name.len; struct btrfs_dir_item *di; struct btrfs_path *path; struct btrfs_root *root = BTRFS_I(dir)->root; int ret = 0; path = btrfs_alloc_path(); BUG_ON(!path); di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name, namelen, 0); if (IS_ERR(di)) ret = PTR_ERR(di); if (IS_ERR_OR_NULL(di)) goto out_err; btrfs_dir_item_key_to_cpu(path->nodes[0], di, location); out: btrfs_free_path(path); return ret; out_err: location->objectid = 0; goto out; } /* * when we hit a tree root in a directory, the btrfs part of the inode * needs to be changed to reflect the root directory of the tree root. This * is kind of like crossing a mount point. */ static int fixup_tree_root_location(struct btrfs_root *root, struct inode *dir, struct dentry *dentry, struct btrfs_key *location, struct btrfs_root **sub_root) { struct btrfs_path *path; struct btrfs_root *new_root; struct btrfs_root_ref *ref; struct extent_buffer *leaf; int ret; int err = 0; path = btrfs_alloc_path(); if (!path) { err = -ENOMEM; goto out; } err = -ENOENT; ret = btrfs_find_root_ref(root->fs_info->tree_root, path, BTRFS_I(dir)->root->root_key.objectid, location->objectid); if (ret) { if (ret < 0) err = ret; goto out; } leaf = path->nodes[0]; ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref); if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) || btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len) goto out; ret = memcmp_extent_buffer(leaf, dentry->d_name.name, (unsigned long)(ref + 1), dentry->d_name.len); if (ret) goto out; btrfs_release_path(path); new_root = btrfs_read_fs_root_no_name(root->fs_info, location); if (IS_ERR(new_root)) { err = PTR_ERR(new_root); goto out; } if (btrfs_root_refs(&new_root->root_item) == 0) { err = -ENOENT; goto out; } *sub_root = new_root; location->objectid = btrfs_root_dirid(&new_root->root_item); location->type = BTRFS_INODE_ITEM_KEY; location->offset = 0; err = 0; out: btrfs_free_path(path); return err; } static void inode_tree_add(struct inode *inode) { struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_inode *entry; struct rb_node **p; struct rb_node *parent; u64 ino = btrfs_ino(inode); again: p = &root->inode_tree.rb_node; parent = NULL; if (inode_unhashed(inode)) return; spin_lock(&root->inode_lock); while (*p) { parent = *p; entry = rb_entry(parent, struct btrfs_inode, rb_node); if (ino < btrfs_ino(&entry->vfs_inode)) p = &parent->rb_left; else if (ino > btrfs_ino(&entry->vfs_inode)) p = &parent->rb_right; else { WARN_ON(!(entry->vfs_inode.i_state & (I_WILL_FREE | I_FREEING))); rb_erase(parent, &root->inode_tree); RB_CLEAR_NODE(parent); spin_unlock(&root->inode_lock); goto again; } } rb_link_node(&BTRFS_I(inode)->rb_node, parent, p); rb_insert_color(&BTRFS_I(inode)->rb_node, &root->inode_tree); spin_unlock(&root->inode_lock); } static void inode_tree_del(struct inode *inode) { struct btrfs_root *root = BTRFS_I(inode)->root; int empty = 0; spin_lock(&root->inode_lock); if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) { rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree); RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node); empty = RB_EMPTY_ROOT(&root->inode_tree); } spin_unlock(&root->inode_lock); /* * Free space cache has inodes in the tree root, but the tree root has a * root_refs of 0, so this could end up dropping the tree root as a * snapshot, so we need the extra !root->fs_info->tree_root check to * make sure we don't drop it. */ if (empty && btrfs_root_refs(&root->root_item) == 0 && root != root->fs_info->tree_root) { synchronize_srcu(&root->fs_info->subvol_srcu); spin_lock(&root->inode_lock); empty = RB_EMPTY_ROOT(&root->inode_tree); spin_unlock(&root->inode_lock); if (empty) btrfs_add_dead_root(root); } } int btrfs_invalidate_inodes(struct btrfs_root *root) { struct rb_node *node; struct rb_node *prev; struct btrfs_inode *entry; struct inode *inode; u64 objectid = 0; WARN_ON(btrfs_root_refs(&root->root_item) != 0); spin_lock(&root->inode_lock); again: node = root->inode_tree.rb_node; prev = NULL; while (node) { prev = node; entry = rb_entry(node, struct btrfs_inode, rb_node); if (objectid < btrfs_ino(&entry->vfs_inode)) node = node->rb_left; else if (objectid > btrfs_ino(&entry->vfs_inode)) node = node->rb_right; else break; } if (!node) { while (prev) { entry = rb_entry(prev, struct btrfs_inode, rb_node); if (objectid <= btrfs_ino(&entry->vfs_inode)) { node = prev; break; } prev = rb_next(prev); } } while (node) { entry = rb_entry(node, struct btrfs_inode, rb_node); objectid = btrfs_ino(&entry->vfs_inode) + 1; inode = igrab(&entry->vfs_inode); if (inode) { spin_unlock(&root->inode_lock); if (atomic_read(&inode->i_count) > 1) d_prune_aliases(inode); /* * btrfs_drop_inode will have it removed from * the inode cache when its usage count * hits zero. */ iput(inode); cond_resched(); spin_lock(&root->inode_lock); goto again; } if (cond_resched_lock(&root->inode_lock)) goto again; node = rb_next(node); } spin_unlock(&root->inode_lock); return 0; } static int btrfs_init_locked_inode(struct inode *inode, void *p) { struct btrfs_iget_args *args = p; inode->i_ino = args->ino; BTRFS_I(inode)->root = args->root; btrfs_set_inode_space_info(args->root, inode); return 0; } static int btrfs_find_actor(struct inode *inode, void *opaque) { struct btrfs_iget_args *args = opaque; return args->ino == btrfs_ino(inode) && args->root == BTRFS_I(inode)->root; } static struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid, struct btrfs_root *root) { struct inode *inode; struct btrfs_iget_args args; args.ino = objectid; args.root = root; inode = iget5_locked(s, objectid, btrfs_find_actor, btrfs_init_locked_inode, (void *)&args); return inode; } /* Get an inode object given its location and corresponding root. * Returns in *is_new if the inode was read from disk */ struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location, struct btrfs_root *root, int *new) { struct inode *inode; inode = btrfs_iget_locked(s, location->objectid, root); if (!inode) return ERR_PTR(-ENOMEM); if (inode->i_state & I_NEW) { BTRFS_I(inode)->root = root; memcpy(&BTRFS_I(inode)->location, location, sizeof(*location)); btrfs_read_locked_inode(inode); inode_tree_add(inode); unlock_new_inode(inode); if (new) *new = 1; } return inode; } static struct inode *new_simple_dir(struct super_block *s, struct btrfs_key *key, struct btrfs_root *root) { struct inode *inode = new_inode(s); if (!inode) return ERR_PTR(-ENOMEM); BTRFS_I(inode)->root = root; memcpy(&BTRFS_I(inode)->location, key, sizeof(*key)); BTRFS_I(inode)->dummy_inode = 1; inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID; inode->i_op = &simple_dir_inode_operations; inode->i_fop = &simple_dir_operations; inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO; inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; return inode; } struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry) { struct inode *inode; struct btrfs_root *root = BTRFS_I(dir)->root; struct btrfs_root *sub_root = root; struct btrfs_key location; int index; int ret; if (dentry->d_name.len > BTRFS_NAME_LEN) return ERR_PTR(-ENAMETOOLONG); ret = btrfs_inode_by_name(dir, dentry, &location); if (ret < 0) return ERR_PTR(ret); if (location.objectid == 0) return NULL; if (location.type == BTRFS_INODE_ITEM_KEY) { inode = btrfs_iget(dir->i_sb, &location, root, NULL); return inode; } BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY); index = srcu_read_lock(&root->fs_info->subvol_srcu); ret = fixup_tree_root_location(root, dir, dentry, &location, &sub_root); if (ret < 0) { if (ret != -ENOENT) inode = ERR_PTR(ret); else inode = new_simple_dir(dir->i_sb, &location, sub_root); } else { inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL); } srcu_read_unlock(&root->fs_info->subvol_srcu, index); if (!IS_ERR(inode) && root != sub_root) { down_read(&root->fs_info->cleanup_work_sem); if (!(inode->i_sb->s_flags & MS_RDONLY)) ret = btrfs_orphan_cleanup(sub_root); up_read(&root->fs_info->cleanup_work_sem); if (ret) inode = ERR_PTR(ret); } return inode; } static int btrfs_dentry_delete(const struct dentry *dentry) { struct btrfs_root *root; if (!dentry->d_inode && !IS_ROOT(dentry)) dentry = dentry->d_parent; if (dentry->d_inode) { root = BTRFS_I(dentry->d_inode)->root; if (btrfs_root_refs(&root->root_item) == 0) return 1; } return 0; } static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) { struct inode *inode; inode = btrfs_lookup_dentry(dir, dentry); if (IS_ERR(inode)) return ERR_CAST(inode); return d_splice_alias(inode, dentry); } unsigned char btrfs_filetype_table[] = { DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK }; static int btrfs_real_readdir(struct file *filp, void *dirent, filldir_t filldir) { struct inode *inode = filp->f_dentry->d_inode; struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_item *item; struct btrfs_dir_item *di; struct btrfs_key key; struct btrfs_key found_key; struct btrfs_path *path; struct list_head ins_list; struct list_head del_list; int ret; struct extent_buffer *leaf; int slot; unsigned char d_type; int over = 0; u32 di_cur; u32 di_total; u32 di_len; int key_type = BTRFS_DIR_INDEX_KEY; char tmp_name[32]; char *name_ptr; int name_len; int is_curr = 0; /* filp->f_pos points to the current index? */ /* FIXME, use a real flag for deciding about the key type */ if (root->fs_info->tree_root == root) key_type = BTRFS_DIR_ITEM_KEY; /* special case for "." */ if (filp->f_pos == 0) { over = filldir(dirent, ".", 1, 1, btrfs_ino(inode), DT_DIR); if (over) return 0; filp->f_pos = 1; } /* special case for .., just use the back ref */ if (filp->f_pos == 1) { u64 pino = parent_ino(filp->f_path.dentry); over = filldir(dirent, "..", 2, 2, pino, DT_DIR); if (over) return 0; filp->f_pos = 2; } path = btrfs_alloc_path(); if (!path) return -ENOMEM; path->reada = 1; if (key_type == BTRFS_DIR_INDEX_KEY) { INIT_LIST_HEAD(&ins_list); INIT_LIST_HEAD(&del_list); btrfs_get_delayed_items(inode, &ins_list, &del_list); } btrfs_set_key_type(&key, key_type); key.offset = filp->f_pos; key.objectid = btrfs_ino(inode); ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) goto err; while (1) { leaf = path->nodes[0]; slot = path->slots[0]; if (slot >= btrfs_header_nritems(leaf)) { ret = btrfs_next_leaf(root, path); if (ret < 0) goto err; else if (ret > 0) break; continue; } item = btrfs_item_nr(leaf, slot); btrfs_item_key_to_cpu(leaf, &found_key, slot); if (found_key.objectid != key.objectid) break; if (btrfs_key_type(&found_key) != key_type) break; if (found_key.offset < filp->f_pos) goto next; if (key_type == BTRFS_DIR_INDEX_KEY && btrfs_should_delete_dir_index(&del_list, found_key.offset)) goto next; filp->f_pos = found_key.offset; is_curr = 1; di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item); di_cur = 0; di_total = btrfs_item_size(leaf, item); while (di_cur < di_total) { struct btrfs_key location; if (verify_dir_item(root, leaf, di)) break; name_len = btrfs_dir_name_len(leaf, di); if (name_len <= sizeof(tmp_name)) { name_ptr = tmp_name; } else { name_ptr = kmalloc(name_len, GFP_NOFS); if (!name_ptr) { ret = -ENOMEM; goto err; } } read_extent_buffer(leaf, name_ptr, (unsigned long)(di + 1), name_len); d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)]; btrfs_dir_item_key_to_cpu(leaf, di, &location); /* is this a reference to our own snapshot? If so * skip it */ if (location.type == BTRFS_ROOT_ITEM_KEY && location.objectid == root->root_key.objectid) { over = 0; goto skip; } over = filldir(dirent, name_ptr, name_len, found_key.offset, location.objectid, d_type); skip: if (name_ptr != tmp_name) kfree(name_ptr); if (over) goto nopos; di_len = btrfs_dir_name_len(leaf, di) + btrfs_dir_data_len(leaf, di) + sizeof(*di); di_cur += di_len; di = (struct btrfs_dir_item *)((char *)di + di_len); } next: path->slots[0]++; } if (key_type == BTRFS_DIR_INDEX_KEY) { if (is_curr) filp->f_pos++; ret = btrfs_readdir_delayed_dir_index(filp, dirent, filldir, &ins_list); if (ret) goto nopos; } /* Reached end of directory/root. Bump pos past the last item. */ if (key_type == BTRFS_DIR_INDEX_KEY) /* * 32-bit glibc will use getdents64, but then strtol - * so the last number we can serve is this. */ filp->f_pos = 0x7fffffff; else filp->f_pos++; nopos: ret = 0; err: if (key_type == BTRFS_DIR_INDEX_KEY) btrfs_put_delayed_items(&ins_list, &del_list); btrfs_free_path(path); return ret; } int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc) { struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_trans_handle *trans; int ret = 0; bool nolock = false; if (BTRFS_I(inode)->dummy_inode) return 0; if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(root, inode)) nolock = true; if (wbc->sync_mode == WB_SYNC_ALL) { if (nolock) trans = btrfs_join_transaction_nolock(root); else trans = btrfs_join_transaction(root); if (IS_ERR(trans)) return PTR_ERR(trans); if (nolock) ret = btrfs_end_transaction_nolock(trans, root); else ret = btrfs_commit_transaction(trans, root); } return ret; } /* * This is somewhat expensive, updating the tree every time the * inode changes. But, it is most likely to find the inode in cache. * FIXME, needs more benchmarking...there are no reasons other than performance * to keep or drop this code. */ void btrfs_dirty_inode(struct inode *inode, int flags) { struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_trans_handle *trans; int ret; if (BTRFS_I(inode)->dummy_inode) return; trans = btrfs_join_transaction(root); BUG_ON(IS_ERR(trans)); ret = btrfs_update_inode(trans, root, inode); if (ret && ret == -ENOSPC) { /* whoops, lets try again with the full transaction */ btrfs_end_transaction(trans, root); trans = btrfs_start_transaction(root, 1); if (IS_ERR(trans)) { printk_ratelimited(KERN_ERR "btrfs: fail to " "dirty inode %llu error %ld\n", (unsigned long long)btrfs_ino(inode), PTR_ERR(trans)); return; } ret = btrfs_update_inode(trans, root, inode); if (ret) { printk_ratelimited(KERN_ERR "btrfs: fail to " "dirty inode %llu error %d\n", (unsigned long long)btrfs_ino(inode), ret); } } btrfs_end_transaction(trans, root); if (BTRFS_I(inode)->delayed_node) btrfs_balance_delayed_items(root); } /* * find the highest existing sequence number in a directory * and then set the in-memory index_cnt variable to reflect * free sequence numbers */ static int btrfs_set_inode_index_count(struct inode *inode) { struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_key key, found_key; struct btrfs_path *path; struct extent_buffer *leaf; int ret; key.objectid = btrfs_ino(inode); btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY); key.offset = (u64)-1; path = btrfs_alloc_path(); if (!path) return -ENOMEM; ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) goto out; /* FIXME: we should be able to handle this */ if (ret == 0) goto out; ret = 0; /* * MAGIC NUMBER EXPLANATION: * since we search a directory based on f_pos we have to start at 2 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody * else has to start at 2 */ if (path->slots[0] == 0) { BTRFS_I(inode)->index_cnt = 2; goto out; } path->slots[0]--; leaf = path->nodes[0]; btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); if (found_key.objectid != btrfs_ino(inode) || btrfs_key_type(&found_key) != BTRFS_DIR_INDEX_KEY) { BTRFS_I(inode)->index_cnt = 2; goto out; } BTRFS_I(inode)->index_cnt = found_key.offset + 1; out: btrfs_free_path(path); return ret; } /* * helper to find a free sequence number in a given directory. This current * code is very simple, later versions will do smarter things in the btree */ int btrfs_set_inode_index(struct inode *dir, u64 *index) { int ret = 0; if (BTRFS_I(dir)->index_cnt == (u64)-1) { ret = btrfs_inode_delayed_dir_index_count(dir); if (ret) { ret = btrfs_set_inode_index_count(dir); if (ret) return ret; } } *index = BTRFS_I(dir)->index_cnt; BTRFS_I(dir)->index_cnt++; return ret; } static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct inode *dir, const char *name, int name_len, u64 ref_objectid, u64 objectid, int mode, u64 *index) { struct inode *inode; struct btrfs_inode_item *inode_item; struct btrfs_key *location; struct btrfs_path *path; struct btrfs_inode_ref *ref; struct btrfs_key key[2]; u32 sizes[2]; unsigned long ptr; int ret; int owner; path = btrfs_alloc_path(); BUG_ON(!path); inode = new_inode(root->fs_info->sb); if (!inode) { btrfs_free_path(path); return ERR_PTR(-ENOMEM); } /* * we have to initialize this early, so we can reclaim the inode * number if we fail afterwards in this function. */ inode->i_ino = objectid; if (dir) { trace_btrfs_inode_request(dir); ret = btrfs_set_inode_index(dir, index); if (ret) { btrfs_free_path(path); iput(inode); return ERR_PTR(ret); } } /* * index_cnt is ignored for everything but a dir, * btrfs_get_inode_index_count has an explanation for the magic * number */ BTRFS_I(inode)->index_cnt = 2; BTRFS_I(inode)->root = root; BTRFS_I(inode)->generation = trans->transid; inode->i_generation = BTRFS_I(inode)->generation; btrfs_set_inode_space_info(root, inode); if (mode & S_IFDIR) owner = 0; else owner = 1; key[0].objectid = objectid; btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY); key[0].offset = 0; key[1].objectid = objectid; btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY); key[1].offset = ref_objectid; sizes[0] = sizeof(struct btrfs_inode_item); sizes[1] = name_len + sizeof(*ref); path->leave_spinning = 1; ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2); if (ret != 0) goto fail; inode_init_owner(inode, dir, mode); inode_set_bytes(inode, 0); inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_inode_item); fill_inode_item(trans, path->nodes[0], inode_item, inode); ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1, struct btrfs_inode_ref); btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len); btrfs_set_inode_ref_index(path->nodes[0], ref, *index); ptr = (unsigned long)(ref + 1); write_extent_buffer(path->nodes[0], name, ptr, name_len); btrfs_mark_buffer_dirty(path->nodes[0]); btrfs_free_path(path); location = &BTRFS_I(inode)->location; location->objectid = objectid; location->offset = 0; btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY); btrfs_inherit_iflags(inode, dir); if ((mode & S_IFREG)) { if (btrfs_test_opt(root, NODATASUM)) BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM; if (btrfs_test_opt(root, NODATACOW) || (BTRFS_I(dir)->flags & BTRFS_INODE_NODATACOW)) BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW; } insert_inode_hash(inode); inode_tree_add(inode); trace_btrfs_inode_new(inode); btrfs_set_inode_last_trans(trans, inode); return inode; fail: if (dir) BTRFS_I(dir)->index_cnt--; btrfs_free_path(path); iput(inode); return ERR_PTR(ret); } static inline u8 btrfs_inode_type(struct inode *inode) { return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT]; } /* * utility function to add 'inode' into 'parent_inode' with * a give name and a given sequence number. * if 'add_backref' is true, also insert a backref from the * inode to the parent directory. */ int btrfs_add_link(struct btrfs_trans_handle *trans, struct inode *parent_inode, struct inode *inode, const char *name, int name_len, int add_backref, u64 index) { int ret = 0; struct btrfs_key key; struct btrfs_root *root = BTRFS_I(parent_inode)->root; u64 ino = btrfs_ino(inode); u64 parent_ino = btrfs_ino(parent_inode); if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) { memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key)); } else { key.objectid = ino; btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY); key.offset = 0; } if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) { ret = btrfs_add_root_ref(trans, root->fs_info->tree_root, key.objectid, root->root_key.objectid, parent_ino, index, name, name_len); } else if (add_backref) { ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino, parent_ino, index); } if (ret == 0) { ret = btrfs_insert_dir_item(trans, root, name, name_len, parent_inode, &key, btrfs_inode_type(inode), index); BUG_ON(ret); btrfs_i_size_write(parent_inode, parent_inode->i_size + name_len * 2); parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME; ret = btrfs_update_inode(trans, root, parent_inode); } return ret; } static int btrfs_add_nondir(struct btrfs_trans_handle *trans, struct inode *dir, struct dentry *dentry, struct inode *inode, int backref, u64 index) { int err = btrfs_add_link(trans, dir, inode, dentry->d_name.name, dentry->d_name.len, backref, index); if (!err) { d_instantiate(dentry, inode); return 0; } if (err > 0) err = -EEXIST; return err; } static int btrfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev) { struct btrfs_trans_handle *trans; struct btrfs_root *root = BTRFS_I(dir)->root; struct inode *inode = NULL; int err; int drop_inode = 0; u64 objectid; unsigned long nr = 0; u64 index = 0; if (!new_valid_dev(rdev)) return -EINVAL; /* * 2 for inode item and ref * 2 for dir items * 1 for xattr if selinux is on */ trans = btrfs_start_transaction(root, 5); if (IS_ERR(trans)) return PTR_ERR(trans); err = btrfs_find_free_ino(root, &objectid); if (err) goto out_unlock; inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, dentry->d_name.len, btrfs_ino(dir), objectid, mode, &index); if (IS_ERR(inode)) { err = PTR_ERR(inode); goto out_unlock; } err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); if (err) { drop_inode = 1; goto out_unlock; } err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index); if (err) drop_inode = 1; else { inode->i_op = &btrfs_special_inode_operations; init_special_inode(inode, inode->i_mode, rdev); btrfs_update_inode(trans, root, inode); } out_unlock: nr = trans->blocks_used; btrfs_end_transaction_throttle(trans, root); btrfs_btree_balance_dirty(root, nr); if (drop_inode) { inode_dec_link_count(inode); iput(inode); } return err; } static int btrfs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd) { struct btrfs_trans_handle *trans; struct btrfs_root *root = BTRFS_I(dir)->root; struct inode *inode = NULL; int drop_inode = 0; int err; unsigned long nr = 0; u64 objectid; u64 index = 0; /* * 2 for inode item and ref * 2 for dir items * 1 for xattr if selinux is on */ trans = btrfs_start_transaction(root, 5); if (IS_ERR(trans)) return PTR_ERR(trans); err = btrfs_find_free_ino(root, &objectid); if (err) goto out_unlock; inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, dentry->d_name.len, btrfs_ino(dir), objectid, mode, &index); if (IS_ERR(inode)) { err = PTR_ERR(inode); goto out_unlock; } err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); if (err) { drop_inode = 1; goto out_unlock; } err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index); if (err) drop_inode = 1; else { inode->i_mapping->a_ops = &btrfs_aops; inode->i_mapping->backing_dev_info = &root->fs_info->bdi; inode->i_fop = &btrfs_file_operations; inode->i_op = &btrfs_file_inode_operations; BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; } out_unlock: nr = trans->blocks_used; btrfs_end_transaction_throttle(trans, root); if (drop_inode) { inode_dec_link_count(inode); iput(inode); } btrfs_btree_balance_dirty(root, nr); return err; } static int btrfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry) { struct btrfs_trans_handle *trans; struct btrfs_root *root = BTRFS_I(dir)->root; struct inode *inode = old_dentry->d_inode; u64 index; unsigned long nr = 0; int err; int drop_inode = 0; /* do not allow sys_link's with other subvols of the same device */ if (root->objectid != BTRFS_I(inode)->root->objectid) return -EXDEV; if (inode->i_nlink == ~0U) return -EMLINK; err = btrfs_set_inode_index(dir, &index); if (err) goto fail; /* * 2 items for inode and inode ref * 2 items for dir items * 1 item for parent inode */ trans = btrfs_start_transaction(root, 5); if (IS_ERR(trans)) { err = PTR_ERR(trans); goto fail; } btrfs_inc_nlink(inode); inode->i_ctime = CURRENT_TIME; ihold(inode); err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index); if (err) { drop_inode = 1; } else { struct dentry *parent = dget_parent(dentry); err = btrfs_update_inode(trans, root, inode); BUG_ON(err); btrfs_log_new_name(trans, inode, NULL, parent); dput(parent); } nr = trans->blocks_used; btrfs_end_transaction_throttle(trans, root); fail: if (drop_inode) { inode_dec_link_count(inode); iput(inode); } btrfs_btree_balance_dirty(root, nr); return err; } static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) { struct inode *inode = NULL; struct btrfs_trans_handle *trans; struct btrfs_root *root = BTRFS_I(dir)->root; int err = 0; int drop_on_err = 0; u64 objectid = 0; u64 index = 0; unsigned long nr = 1; /* * 2 items for inode and ref * 2 items for dir items * 1 for xattr if selinux is on */ trans = btrfs_start_transaction(root, 5); if (IS_ERR(trans)) return PTR_ERR(trans); err = btrfs_find_free_ino(root, &objectid); if (err) goto out_fail; inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, dentry->d_name.len, btrfs_ino(dir), objectid, S_IFDIR | mode, &index); if (IS_ERR(inode)) { err = PTR_ERR(inode); goto out_fail; } drop_on_err = 1; err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); if (err) goto out_fail; inode->i_op = &btrfs_dir_inode_operations; inode->i_fop = &btrfs_dir_file_operations; btrfs_i_size_write(inode, 0); err = btrfs_update_inode(trans, root, inode); if (err) goto out_fail; err = btrfs_add_link(trans, dir, inode, dentry->d_name.name, dentry->d_name.len, 0, index); if (err) goto out_fail; d_instantiate(dentry, inode); drop_on_err = 0; out_fail: nr = trans->blocks_used; btrfs_end_transaction_throttle(trans, root); if (drop_on_err) iput(inode); btrfs_btree_balance_dirty(root, nr); return err; } /* helper for btfs_get_extent. Given an existing extent in the tree, * and an extent that you want to insert, deal with overlap and insert * the new extent into the tree. */ static int merge_extent_mapping(struct extent_map_tree *em_tree, struct extent_map *existing, struct extent_map *em, u64 map_start, u64 map_len) { u64 start_diff; BUG_ON(map_start < em->start || map_start >= extent_map_end(em)); start_diff = map_start - em->start; em->start = map_start; em->len = map_len; if (em->block_start < EXTENT_MAP_LAST_BYTE && !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) { em->block_start += start_diff; em->block_len -= start_diff; } return add_extent_mapping(em_tree, em); } static noinline int uncompress_inline(struct btrfs_path *path, struct inode *inode, struct page *page, size_t pg_offset, u64 extent_offset, struct btrfs_file_extent_item *item) { int ret; struct extent_buffer *leaf = path->nodes[0]; char *tmp; size_t max_size; unsigned long inline_size; unsigned long ptr; int compress_type; WARN_ON(pg_offset != 0); compress_type = btrfs_file_extent_compression(leaf, item); max_size = btrfs_file_extent_ram_bytes(leaf, item); inline_size = btrfs_file_extent_inline_item_len(leaf, btrfs_item_nr(leaf, path->slots[0])); tmp = kmalloc(inline_size, GFP_NOFS); if (!tmp) return -ENOMEM; ptr = btrfs_file_extent_inline_start(item); read_extent_buffer(leaf, tmp, ptr, inline_size); max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size); ret = btrfs_decompress(compress_type, tmp, page, extent_offset, inline_size, max_size); if (ret) { char *kaddr = kmap_atomic(page, KM_USER0); unsigned long copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset, max_size - extent_offset); memset(kaddr + pg_offset, 0, copy_size); kunmap_atomic(kaddr, KM_USER0); } kfree(tmp); return 0; } /* * a bit scary, this does extent mapping from logical file offset to the disk. * the ugly parts come from merging extents from the disk with the in-ram * representation. This gets more complex because of the data=ordered code, * where the in-ram extents might be locked pending data=ordered completion. * * This also copies inline extents directly into the page. */ struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page, size_t pg_offset, u64 start, u64 len, int create) { int ret; int err = 0; u64 bytenr; u64 extent_start = 0; u64 extent_end = 0; u64 objectid = btrfs_ino(inode); u32 found_type; struct btrfs_path *path = NULL; struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_file_extent_item *item; struct extent_buffer *leaf; struct btrfs_key found_key; struct extent_map *em = NULL; struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; struct btrfs_trans_handle *trans = NULL; int compress_type; again: read_lock(&em_tree->lock); em = lookup_extent_mapping(em_tree, start, len); if (em) em->bdev = root->fs_info->fs_devices->latest_bdev; read_unlock(&em_tree->lock); if (em) { if (em->start > start || em->start + em->len <= start) free_extent_map(em); else if (em->block_start == EXTENT_MAP_INLINE && page) free_extent_map(em); else goto out; } em = alloc_extent_map(); if (!em) { err = -ENOMEM; goto out; } em->bdev = root->fs_info->fs_devices->latest_bdev; em->start = EXTENT_MAP_HOLE; em->orig_start = EXTENT_MAP_HOLE; em->len = (u64)-1; em->block_len = (u64)-1; if (!path) { path = btrfs_alloc_path(); if (!path) { err = -ENOMEM; goto out; } /* * Chances are we'll be called again, so go ahead and do * readahead */ path->reada = 1; } ret = btrfs_lookup_file_extent(trans, root, path, objectid, start, trans != NULL); if (ret < 0) { err = ret; goto out; } if (ret != 0) { if (path->slots[0] == 0) goto not_found; path->slots[0]--; } leaf = path->nodes[0]; item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); /* are we inside the extent that was found? */ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); found_type = btrfs_key_type(&found_key); if (found_key.objectid != objectid || found_type != BTRFS_EXTENT_DATA_KEY) { goto not_found; } found_type = btrfs_file_extent_type(leaf, item); extent_start = found_key.offset; compress_type = btrfs_file_extent_compression(leaf, item); if (found_type == BTRFS_FILE_EXTENT_REG || found_type == BTRFS_FILE_EXTENT_PREALLOC) { extent_end = extent_start + btrfs_file_extent_num_bytes(leaf, item); } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { size_t size; size = btrfs_file_extent_inline_len(leaf, item); extent_end = (extent_start + size + root->sectorsize - 1) & ~((u64)root->sectorsize - 1); } if (start >= extent_end) { path->slots[0]++; if (path->slots[0] >= btrfs_header_nritems(leaf)) { ret = btrfs_next_leaf(root, path); if (ret < 0) { err = ret; goto out; } if (ret > 0) goto not_found; leaf = path->nodes[0]; } btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); if (found_key.objectid != objectid || found_key.type != BTRFS_EXTENT_DATA_KEY) goto not_found; if (start + len <= found_key.offset) goto not_found; em->start = start; em->len = found_key.offset - start; goto not_found_em; } if (found_type == BTRFS_FILE_EXTENT_REG || found_type == BTRFS_FILE_EXTENT_PREALLOC) { em->start = extent_start; em->len = extent_end - extent_start; em->orig_start = extent_start - btrfs_file_extent_offset(leaf, item); bytenr = btrfs_file_extent_disk_bytenr(leaf, item); if (bytenr == 0) { em->block_start = EXTENT_MAP_HOLE; goto insert; } if (compress_type != BTRFS_COMPRESS_NONE) { set_bit(EXTENT_FLAG_COMPRESSED, &em->flags); em->compress_type = compress_type; em->block_start = bytenr; em->block_len = btrfs_file_extent_disk_num_bytes(leaf, item); } else { bytenr += btrfs_file_extent_offset(leaf, item); em->block_start = bytenr; em->block_len = em->len; if (found_type == BTRFS_FILE_EXTENT_PREALLOC) set_bit(EXTENT_FLAG_PREALLOC, &em->flags); } goto insert; } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { unsigned long ptr; char *map; size_t size; size_t extent_offset; size_t copy_size; em->block_start = EXTENT_MAP_INLINE; if (!page || create) { em->start = extent_start; em->len = extent_end - extent_start; goto out; } size = btrfs_file_extent_inline_len(leaf, item); extent_offset = page_offset(page) + pg_offset - extent_start; copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset, size - extent_offset); em->start = extent_start + extent_offset; em->len = (copy_size + root->sectorsize - 1) & ~((u64)root->sectorsize - 1); em->orig_start = EXTENT_MAP_INLINE; if (compress_type) { set_bit(EXTENT_FLAG_COMPRESSED, &em->flags); em->compress_type = compress_type; } ptr = btrfs_file_extent_inline_start(item) + extent_offset; if (create == 0 && !PageUptodate(page)) { if (btrfs_file_extent_compression(leaf, item) != BTRFS_COMPRESS_NONE) { ret = uncompress_inline(path, inode, page, pg_offset, extent_offset, item); BUG_ON(ret); } else { map = kmap(page); read_extent_buffer(leaf, map + pg_offset, ptr, copy_size); if (pg_offset + copy_size < PAGE_CACHE_SIZE) { memset(map + pg_offset + copy_size, 0, PAGE_CACHE_SIZE - pg_offset - copy_size); } kunmap(page); } flush_dcache_page(page); } else if (create && PageUptodate(page)) { WARN_ON(1); if (!trans) { kunmap(page); free_extent_map(em); em = NULL; btrfs_release_path(path); trans = btrfs_join_transaction(root); if (IS_ERR(trans)) return ERR_CAST(trans); goto again; } map = kmap(page); write_extent_buffer(leaf, map + pg_offset, ptr, copy_size); kunmap(page); btrfs_mark_buffer_dirty(leaf); } set_extent_uptodate(io_tree, em->start, extent_map_end(em) - 1, NULL, GFP_NOFS); goto insert; } else { printk(KERN_ERR "btrfs unknown found_type %d\n", found_type); WARN_ON(1); } not_found: em->start = start; em->len = len; not_found_em: em->block_start = EXTENT_MAP_HOLE; set_bit(EXTENT_FLAG_VACANCY, &em->flags); insert: btrfs_release_path(path); if (em->start > start || extent_map_end(em) <= start) { printk(KERN_ERR "Btrfs: bad extent! em: [%llu %llu] passed " "[%llu %llu]\n", (unsigned long long)em->start, (unsigned long long)em->len, (unsigned long long)start, (unsigned long long)len); err = -EIO; goto out; } err = 0; write_lock(&em_tree->lock); ret = add_extent_mapping(em_tree, em); /* it is possible that someone inserted the extent into the tree * while we had the lock dropped. It is also possible that * an overlapping map exists in the tree */ if (ret == -EEXIST) { struct extent_map *existing; ret = 0; existing = lookup_extent_mapping(em_tree, start, len); if (existing && (existing->start > start || existing->start + existing->len <= start)) { free_extent_map(existing); existing = NULL; } if (!existing) { existing = lookup_extent_mapping(em_tree, em->start, em->len); if (existing) { err = merge_extent_mapping(em_tree, existing, em, start, root->sectorsize); free_extent_map(existing); if (err) { free_extent_map(em); em = NULL; } } else { err = -EIO; free_extent_map(em); em = NULL; } } else { free_extent_map(em); em = existing; err = 0; } } write_unlock(&em_tree->lock); out: trace_btrfs_get_extent(root, em); if (path) btrfs_free_path(path); if (trans) { ret = btrfs_end_transaction(trans, root); if (!err) err = ret; } if (err) { free_extent_map(em); return ERR_PTR(err); } return em; } struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page, size_t pg_offset, u64 start, u64 len, int create) { struct extent_map *em; struct extent_map *hole_em = NULL; u64 range_start = start; u64 end; u64 found; u64 found_end; int err = 0; em = btrfs_get_extent(inode, page, pg_offset, start, len, create); if (IS_ERR(em)) return em; if (em) { /* * if our em maps to a hole, there might * actually be delalloc bytes behind it */ if (em->block_start != EXTENT_MAP_HOLE) return em; else hole_em = em; } /* check to see if we've wrapped (len == -1 or similar) */ end = start + len; if (end < start) end = (u64)-1; else end -= 1; em = NULL; /* ok, we didn't find anything, lets look for delalloc */ found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start, end, len, EXTENT_DELALLOC, 1); found_end = range_start + found; if (found_end < range_start) found_end = (u64)-1; /* * we didn't find anything useful, return * the original results from get_extent() */ if (range_start > end || found_end <= start) { em = hole_em; hole_em = NULL; goto out; } /* adjust the range_start to make sure it doesn't * go backwards from the start they passed in */ range_start = max(start,range_start); found = found_end - range_start; if (found > 0) { u64 hole_start = start; u64 hole_len = len; em = alloc_extent_map(); if (!em) { err = -ENOMEM; goto out; } /* * when btrfs_get_extent can't find anything it * returns one huge hole * * make sure what it found really fits our range, and * adjust to make sure it is based on the start from * the caller */ if (hole_em) { u64 calc_end = extent_map_end(hole_em); if (calc_end <= start || (hole_em->start > end)) { free_extent_map(hole_em); hole_em = NULL; } else { hole_start = max(hole_em->start, start); hole_len = calc_end - hole_start; } } em->bdev = NULL; if (hole_em && range_start > hole_start) { /* our hole starts before our delalloc, so we * have to return just the parts of the hole * that go until the delalloc starts */ em->len = min(hole_len, range_start - hole_start); em->start = hole_start; em->orig_start = hole_start; /* * don't adjust block start at all, * it is fixed at EXTENT_MAP_HOLE */ em->block_start = hole_em->block_start; em->block_len = hole_len; } else { em->start = range_start; em->len = found; em->orig_start = range_start; em->block_start = EXTENT_MAP_DELALLOC; em->block_len = found; } } else if (hole_em) { return hole_em; } out: free_extent_map(hole_em); if (err) { free_extent_map(em); return ERR_PTR(err); } return em; } static struct extent_map *btrfs_new_extent_direct(struct inode *inode, struct extent_map *em, u64 start, u64 len) { struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_trans_handle *trans; struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; struct btrfs_key ins; u64 alloc_hint; int ret; bool insert = false; /* * Ok if the extent map we looked up is a hole and is for the exact * range we want, there is no reason to allocate a new one, however if * it is not right then we need to free this one and drop the cache for * our range. */ if (em->block_start != EXTENT_MAP_HOLE || em->start != start || em->len != len) { free_extent_map(em); em = NULL; insert = true; btrfs_drop_extent_cache(inode, start, start + len - 1, 0); } trans = btrfs_join_transaction(root); if (IS_ERR(trans)) return ERR_CAST(trans); if (start <= BTRFS_I(inode)->disk_i_size && len < 64 * 1024) btrfs_add_inode_defrag(trans, inode); trans->block_rsv = &root->fs_info->delalloc_block_rsv; alloc_hint = get_extent_allocation_hint(inode, start, len); ret = btrfs_reserve_extent(trans, root, len, root->sectorsize, 0, alloc_hint, (u64)-1, &ins, 1); if (ret) { em = ERR_PTR(ret); goto out; } if (!em) { em = alloc_extent_map(); if (!em) { em = ERR_PTR(-ENOMEM); goto out; } } em->start = start; em->orig_start = em->start; em->len = ins.offset; em->block_start = ins.objectid; em->block_len = ins.offset; em->bdev = root->fs_info->fs_devices->latest_bdev; /* * We need to do this because if we're using the original em we searched * for, we could have EXTENT_FLAG_VACANCY set, and we don't want that. */ em->flags = 0; set_bit(EXTENT_FLAG_PINNED, &em->flags); while (insert) { write_lock(&em_tree->lock); ret = add_extent_mapping(em_tree, em); write_unlock(&em_tree->lock); if (ret != -EEXIST) break; btrfs_drop_extent_cache(inode, start, start + em->len - 1, 0); } ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid, ins.offset, ins.offset, 0); if (ret) { btrfs_free_reserved_extent(root, ins.objectid, ins.offset); em = ERR_PTR(ret); } out: btrfs_end_transaction(trans, root); return em; } /* * returns 1 when the nocow is safe, < 1 on error, 0 if the * block must be cow'd */ static noinline int can_nocow_odirect(struct btrfs_trans_handle *trans, struct inode *inode, u64 offset, u64 len) { struct btrfs_path *path; int ret; struct extent_buffer *leaf; struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_file_extent_item *fi; struct btrfs_key key; u64 disk_bytenr; u64 backref_offset; u64 extent_end; u64 num_bytes; int slot; int found_type; path = btrfs_alloc_path(); if (!path) return -ENOMEM; ret = btrfs_lookup_file_extent(trans, root, path, btrfs_ino(inode), offset, 0); if (ret < 0) goto out; slot = path->slots[0]; if (ret == 1) { if (slot == 0) { /* can't find the item, must cow */ ret = 0; goto out; } slot--; } ret = 0; leaf = path->nodes[0]; btrfs_item_key_to_cpu(leaf, &key, slot); if (key.objectid != btrfs_ino(inode) || key.type != BTRFS_EXTENT_DATA_KEY) { /* not our file or wrong item type, must cow */ goto out; } if (key.offset > offset) { /* Wrong offset, must cow */ goto out; } fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); found_type = btrfs_file_extent_type(leaf, fi); if (found_type != BTRFS_FILE_EXTENT_REG && found_type != BTRFS_FILE_EXTENT_PREALLOC) { /* not a regular extent, must cow */ goto out; } disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); backref_offset = btrfs_file_extent_offset(leaf, fi); extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi); if (extent_end < offset + len) { /* extent doesn't include our full range, must cow */ goto out; } if (btrfs_extent_readonly(root, disk_bytenr)) goto out; /* * look for other files referencing this extent, if we * find any we must cow */ if (btrfs_cross_ref_exist(trans, root, btrfs_ino(inode), key.offset - backref_offset, disk_bytenr)) goto out; /* * adjust disk_bytenr and num_bytes to cover just the bytes * in this extent we are about to write. If there * are any csums in that range we have to cow in order * to keep the csums correct */ disk_bytenr += backref_offset; disk_bytenr += offset - key.offset; num_bytes = min(offset + len, extent_end) - offset; if (csum_exist_in_range(root, disk_bytenr, num_bytes)) goto out; /* * all of the above have passed, it is safe to overwrite this extent * without cow */ ret = 1; out: btrfs_free_path(path); return ret; } static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) { struct extent_map *em; struct btrfs_root *root = BTRFS_I(inode)->root; u64 start = iblock << inode->i_blkbits; u64 len = bh_result->b_size; struct btrfs_trans_handle *trans; em = btrfs_get_extent(inode, NULL, 0, start, len, 0); if (IS_ERR(em)) return PTR_ERR(em); /* * Ok for INLINE and COMPRESSED extents we need to fallback on buffered * io. INLINE is special, and we could probably kludge it in here, but * it's still buffered so for safety lets just fall back to the generic * buffered path. * * For COMPRESSED we _have_ to read the entire extent in so we can * decompress it, so there will be buffering required no matter what we * do, so go ahead and fallback to buffered. * * We return -ENOTBLK because thats what makes DIO go ahead and go back * to buffered IO. Don't blame me, this is the price we pay for using * the generic code. */ if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) || em->block_start == EXTENT_MAP_INLINE) { free_extent_map(em); return -ENOTBLK; } /* Just a good old fashioned hole, return */ if (!create && (em->block_start == EXTENT_MAP_HOLE || test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) { free_extent_map(em); /* DIO will do one hole at a time, so just unlock a sector */ unlock_extent(&BTRFS_I(inode)->io_tree, start, start + root->sectorsize - 1, GFP_NOFS); return 0; } /* * We don't allocate a new extent in the following cases * * 1) The inode is marked as NODATACOW. In this case we'll just use the * existing extent. * 2) The extent is marked as PREALLOC. We're good to go here and can * just use the extent. * */ if (!create) { len = em->len - (start - em->start); goto map; } if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) || ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) && em->block_start != EXTENT_MAP_HOLE)) { int type; int ret; u64 block_start; if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) type = BTRFS_ORDERED_PREALLOC; else type = BTRFS_ORDERED_NOCOW; len = min(len, em->len - (start - em->start)); block_start = em->block_start + (start - em->start); /* * we're not going to log anything, but we do need * to make sure the current transaction stays open * while we look for nocow cross refs */ trans = btrfs_join_transaction(root); if (IS_ERR(trans)) goto must_cow; if (can_nocow_odirect(trans, inode, start, len) == 1) { ret = btrfs_add_ordered_extent_dio(inode, start, block_start, len, len, type); btrfs_end_transaction(trans, root); if (ret) { free_extent_map(em); return ret; } goto unlock; } btrfs_end_transaction(trans, root); } must_cow: /* * this will cow the extent, reset the len in case we changed * it above */ len = bh_result->b_size; em = btrfs_new_extent_direct(inode, em, start, len); if (IS_ERR(em)) return PTR_ERR(em); len = min(len, em->len - (start - em->start)); unlock: clear_extent_bit(&BTRFS_I(inode)->io_tree, start, start + len - 1, EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DIRTY, 1, 0, NULL, GFP_NOFS); map: bh_result->b_blocknr = (em->block_start + (start - em->start)) >> inode->i_blkbits; bh_result->b_size = len; bh_result->b_bdev = em->bdev; set_buffer_mapped(bh_result); if (create && !test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) set_buffer_new(bh_result); free_extent_map(em); return 0; } struct btrfs_dio_private { struct inode *inode; u64 logical_offset; u64 disk_bytenr; u64 bytes; u32 *csums; void *private; /* number of bios pending for this dio */ atomic_t pending_bios; /* IO errors */ int errors; struct bio *orig_bio; }; static void btrfs_endio_direct_read(struct bio *bio, int err) { struct btrfs_dio_private *dip = bio->bi_private; struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1; struct bio_vec *bvec = bio->bi_io_vec; struct inode *inode = dip->inode; struct btrfs_root *root = BTRFS_I(inode)->root; u64 start; u32 *private = dip->csums; start = dip->logical_offset; do { if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) { struct page *page = bvec->bv_page; char *kaddr; u32 csum = ~(u32)0; unsigned long flags; local_irq_save(flags); kaddr = kmap_atomic(page, KM_IRQ0); csum = btrfs_csum_data(root, kaddr + bvec->bv_offset, csum, bvec->bv_len); btrfs_csum_final(csum, (char *)&csum); kunmap_atomic(kaddr, KM_IRQ0); local_irq_restore(flags); flush_dcache_page(bvec->bv_page); if (csum != *private) { printk(KERN_ERR "btrfs csum failed ino %llu off" " %llu csum %u private %u\n", (unsigned long long)btrfs_ino(inode), (unsigned long long)start, csum, *private); err = -EIO; } } start += bvec->bv_len; private++; bvec++; } while (bvec <= bvec_end); unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset, dip->logical_offset + dip->bytes - 1, GFP_NOFS); bio->bi_private = dip->private; kfree(dip->csums); kfree(dip); /* If we had a csum failure make sure to clear the uptodate flag */ if (err) clear_bit(BIO_UPTODATE, &bio->bi_flags); dio_end_io(bio, err); } static void btrfs_endio_direct_write(struct bio *bio, int err) { struct btrfs_dio_private *dip = bio->bi_private; struct inode *inode = dip->inode; struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_trans_handle *trans; struct btrfs_ordered_extent *ordered = NULL; struct extent_state *cached_state = NULL; u64 ordered_offset = dip->logical_offset; u64 ordered_bytes = dip->bytes; int ret; if (err) goto out_done; again: ret = btrfs_dec_test_first_ordered_pending(inode, &ordered, &ordered_offset, ordered_bytes); if (!ret) goto out_test; BUG_ON(!ordered); trans = btrfs_join_transaction(root); if (IS_ERR(trans)) { err = -ENOMEM; goto out; } trans->block_rsv = &root->fs_info->delalloc_block_rsv; if (test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags)) { ret = btrfs_ordered_update_i_size(inode, 0, ordered); if (!ret) ret = btrfs_update_inode(trans, root, inode); err = ret; goto out; } lock_extent_bits(&BTRFS_I(inode)->io_tree, ordered->file_offset, ordered->file_offset + ordered->len - 1, 0, &cached_state, GFP_NOFS); if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags)) { ret = btrfs_mark_extent_written(trans, inode, ordered->file_offset, ordered->file_offset + ordered->len); if (ret) { err = ret; goto out_unlock; } } else { ret = insert_reserved_file_extent(trans, inode, ordered->file_offset, ordered->start, ordered->disk_len, ordered->len, ordered->len, 0, 0, 0, BTRFS_FILE_EXTENT_REG); unpin_extent_cache(&BTRFS_I(inode)->extent_tree, ordered->file_offset, ordered->len); if (ret) { err = ret; WARN_ON(1); goto out_unlock; } } add_pending_csums(trans, inode, ordered->file_offset, &ordered->list); ret = btrfs_ordered_update_i_size(inode, 0, ordered); if (!ret) btrfs_update_inode(trans, root, inode); ret = 0; out_unlock: unlock_extent_cached(&BTRFS_I(inode)->io_tree, ordered->file_offset, ordered->file_offset + ordered->len - 1, &cached_state, GFP_NOFS); out: btrfs_delalloc_release_metadata(inode, ordered->len); btrfs_end_transaction(trans, root); ordered_offset = ordered->file_offset + ordered->len; btrfs_put_ordered_extent(ordered); btrfs_put_ordered_extent(ordered); out_test: /* * our bio might span multiple ordered extents. If we haven't * completed the accounting for the whole dio, go back and try again */ if (ordered_offset < dip->logical_offset + dip->bytes) { ordered_bytes = dip->logical_offset + dip->bytes - ordered_offset; goto again; } out_done: bio->bi_private = dip->private; kfree(dip->csums); kfree(dip); /* If we had an error make sure to clear the uptodate flag */ if (err) clear_bit(BIO_UPTODATE, &bio->bi_flags); dio_end_io(bio, err); } static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw, struct bio *bio, int mirror_num, unsigned long bio_flags, u64 offset) { int ret; struct btrfs_root *root = BTRFS_I(inode)->root; ret = btrfs_csum_one_bio(root, inode, bio, offset, 1); BUG_ON(ret); return 0; } static void btrfs_end_dio_bio(struct bio *bio, int err) { struct btrfs_dio_private *dip = bio->bi_private; if (err) { printk(KERN_ERR "btrfs direct IO failed ino %llu rw %lu " "sector %#Lx len %u err no %d\n", (unsigned long long)btrfs_ino(dip->inode), bio->bi_rw, (unsigned long long)bio->bi_sector, bio->bi_size, err); dip->errors = 1; /* * before atomic variable goto zero, we must make sure * dip->errors is perceived to be set. */ smp_mb__before_atomic_dec(); } /* if there are more bios still pending for this dio, just exit */ if (!atomic_dec_and_test(&dip->pending_bios)) goto out; if (dip->errors) bio_io_error(dip->orig_bio); else { set_bit(BIO_UPTODATE, &dip->orig_bio->bi_flags); bio_endio(dip->orig_bio, 0); } out: bio_put(bio); } static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev, u64 first_sector, gfp_t gfp_flags) { int nr_vecs = bio_get_nr_vecs(bdev); return btrfs_bio_alloc(bdev, first_sector, nr_vecs, gfp_flags); } static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode, int rw, u64 file_offset, int skip_sum, u32 *csums, int async_submit) { int write = rw & REQ_WRITE; struct btrfs_root *root = BTRFS_I(inode)->root; int ret; bio_get(bio); ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0); if (ret) goto err; if (skip_sum) goto map; if (write && async_submit) { ret = btrfs_wq_submit_bio(root->fs_info, inode, rw, bio, 0, 0, file_offset, __btrfs_submit_bio_start_direct_io, __btrfs_submit_bio_done); goto err; } else if (write) { /* * If we aren't doing async submit, calculate the csum of the * bio now. */ ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1); if (ret) goto err; } else if (!skip_sum) { ret = btrfs_lookup_bio_sums_dio(root, inode, bio, file_offset, csums); if (ret) goto err; } map: ret = btrfs_map_bio(root, rw, bio, 0, async_submit); err: bio_put(bio); return ret; } static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip, int skip_sum) { struct inode *inode = dip->inode; struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree; struct bio *bio; struct bio *orig_bio = dip->orig_bio; struct bio_vec *bvec = orig_bio->bi_io_vec; u64 start_sector = orig_bio->bi_sector; u64 file_offset = dip->logical_offset; u64 submit_len = 0; u64 map_length; int nr_pages = 0; u32 *csums = dip->csums; int ret = 0; int async_submit = 0; int write = rw & REQ_WRITE; map_length = orig_bio->bi_size; ret = btrfs_map_block(map_tree, READ, start_sector << 9, &map_length, NULL, 0); if (ret) { bio_put(orig_bio); return -EIO; } if (map_length >= orig_bio->bi_size) { bio = orig_bio; goto submit; } async_submit = 1; bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS); if (!bio) return -ENOMEM; bio->bi_private = dip; bio->bi_end_io = btrfs_end_dio_bio; atomic_inc(&dip->pending_bios); while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) { if (unlikely(map_length < submit_len + bvec->bv_len || bio_add_page(bio, bvec->bv_page, bvec->bv_len, bvec->bv_offset) < bvec->bv_len)) { /* * inc the count before we submit the bio so * we know the end IO handler won't happen before * we inc the count. Otherwise, the dip might get freed * before we're done setting it up */ atomic_inc(&dip->pending_bios); ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum, csums, async_submit); if (ret) { bio_put(bio); atomic_dec(&dip->pending_bios); goto out_err; } /* Write's use the ordered csums */ if (!write && !skip_sum) csums = csums + nr_pages; start_sector += submit_len >> 9; file_offset += submit_len; submit_len = 0; nr_pages = 0; bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS); if (!bio) goto out_err; bio->bi_private = dip; bio->bi_end_io = btrfs_end_dio_bio; map_length = orig_bio->bi_size; ret = btrfs_map_block(map_tree, READ, start_sector << 9, &map_length, NULL, 0); if (ret) { bio_put(bio); goto out_err; } } else { submit_len += bvec->bv_len; nr_pages ++; bvec++; } } submit: ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum, csums, async_submit); if (!ret) return 0; bio_put(bio); out_err: dip->errors = 1; /* * before atomic variable goto zero, we must * make sure dip->errors is perceived to be set. */ smp_mb__before_atomic_dec(); if (atomic_dec_and_test(&dip->pending_bios)) bio_io_error(dip->orig_bio); /* bio_end_io() will handle error, so we needn't return it */ return 0; } static void btrfs_submit_direct(int rw, struct bio *bio, struct inode *inode, loff_t file_offset) { struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_dio_private *dip; struct bio_vec *bvec = bio->bi_io_vec; int skip_sum; int write = rw & REQ_WRITE; int ret = 0; skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM; dip = kmalloc(sizeof(*dip), GFP_NOFS); if (!dip) { ret = -ENOMEM; goto free_ordered; } dip->csums = NULL; /* Write's use the ordered csum stuff, so we don't need dip->csums */ if (!write && !skip_sum) { dip->csums = kmalloc(sizeof(u32) * bio->bi_vcnt, GFP_NOFS); if (!dip->csums) { kfree(dip); ret = -ENOMEM; goto free_ordered; } } dip->private = bio->bi_private; dip->inode = inode; dip->logical_offset = file_offset; dip->bytes = 0; do { dip->bytes += bvec->bv_len; bvec++; } while (bvec <= (bio->bi_io_vec + bio->bi_vcnt - 1)); dip->disk_bytenr = (u64)bio->bi_sector << 9; bio->bi_private = dip; dip->errors = 0; dip->orig_bio = bio; atomic_set(&dip->pending_bios, 0); if (write) bio->bi_end_io = btrfs_endio_direct_write; else bio->bi_end_io = btrfs_endio_direct_read; ret = btrfs_submit_direct_hook(rw, dip, skip_sum); if (!ret) return; free_ordered: /* * If this is a write, we need to clean up the reserved space and kill * the ordered extent. */ if (write) { struct btrfs_ordered_extent *ordered; ordered = btrfs_lookup_ordered_extent(inode, file_offset); if (!test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags) && !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags)) btrfs_free_reserved_extent(root, ordered->start, ordered->disk_len); btrfs_put_ordered_extent(ordered); btrfs_put_ordered_extent(ordered); } bio_endio(bio, ret); } static ssize_t check_direct_IO(struct btrfs_root *root, int rw, struct kiocb *iocb, const struct iovec *iov, loff_t offset, unsigned long nr_segs) { int seg; int i; size_t size; unsigned long addr; unsigned blocksize_mask = root->sectorsize - 1; ssize_t retval = -EINVAL; loff_t end = offset; if (offset & blocksize_mask) goto out; /* Check the memory alignment. Blocks cannot straddle pages */ for (seg = 0; seg < nr_segs; seg++) { addr = (unsigned long)iov[seg].iov_base; size = iov[seg].iov_len; end += size; if ((addr & blocksize_mask) || (size & blocksize_mask)) goto out; /* If this is a write we don't need to check anymore */ if (rw & WRITE) continue; /* * Check to make sure we don't have duplicate iov_base's in this * iovec, if so return EINVAL, otherwise we'll get csum errors * when reading back. */ for (i = seg + 1; i < nr_segs; i++) { if (iov[seg].iov_base == iov[i].iov_base) goto out; } } retval = 0; out: return retval; } static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, loff_t offset, unsigned long nr_segs) { struct file *file = iocb->ki_filp; struct inode *inode = file->f_mapping->host; struct btrfs_ordered_extent *ordered; struct extent_state *cached_state = NULL; u64 lockstart, lockend; ssize_t ret; int writing = rw & WRITE; int write_bits = 0; size_t count = iov_length(iov, nr_segs); if (check_direct_IO(BTRFS_I(inode)->root, rw, iocb, iov, offset, nr_segs)) { return 0; } lockstart = offset; lockend = offset + count - 1; if (writing) { ret = btrfs_delalloc_reserve_space(inode, count); if (ret) goto out; } while (1) { lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend, 0, &cached_state, GFP_NOFS); /* * We're concerned with the entire range that we're going to be * doing DIO to, so we need to make sure theres no ordered * extents in this range. */ ordered = btrfs_lookup_ordered_range(inode, lockstart, lockend - lockstart + 1); if (!ordered) break; unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend, &cached_state, GFP_NOFS); btrfs_start_ordered_extent(inode, ordered, 1); btrfs_put_ordered_extent(ordered); cond_resched(); } /* * we don't use btrfs_set_extent_delalloc because we don't want * the dirty or uptodate bits */ if (writing) { write_bits = EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING; ret = set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend, EXTENT_DELALLOC, 0, NULL, &cached_state, GFP_NOFS); if (ret) { clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend, EXTENT_LOCKED | write_bits, 1, 0, &cached_state, GFP_NOFS); goto out; } } free_extent_state(cached_state); cached_state = NULL; ret = __blockdev_direct_IO(rw, iocb, inode, BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev, iov, offset, nr_segs, btrfs_get_blocks_direct, NULL, btrfs_submit_direct, 0); if (ret < 0 && ret != -EIOCBQUEUED) { clear_extent_bit(&BTRFS_I(inode)->io_tree, offset, offset + iov_length(iov, nr_segs) - 1, EXTENT_LOCKED | write_bits, 1, 0, &cached_state, GFP_NOFS); } else if (ret >= 0 && ret < iov_length(iov, nr_segs)) { /* * We're falling back to buffered, unlock the section we didn't * do IO on. */ clear_extent_bit(&BTRFS_I(inode)->io_tree, offset + ret, offset + iov_length(iov, nr_segs) - 1, EXTENT_LOCKED | write_bits, 1, 0, &cached_state, GFP_NOFS); } out: free_extent_state(cached_state); return ret; } static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, __u64 start, __u64 len) { return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap); } int btrfs_readpage(struct file *file, struct page *page) { struct extent_io_tree *tree; tree = &BTRFS_I(page->mapping->host)->io_tree; return extent_read_full_page(tree, page, btrfs_get_extent); } static int btrfs_writepage(struct page *page, struct writeback_control *wbc) { struct extent_io_tree *tree; if (current->flags & PF_MEMALLOC) { redirty_page_for_writepage(wbc, page); unlock_page(page); return 0; } tree = &BTRFS_I(page->mapping->host)->io_tree; return extent_write_full_page(tree, page, btrfs_get_extent, wbc); } int btrfs_writepages(struct address_space *mapping, struct writeback_control *wbc) { struct extent_io_tree *tree; tree = &BTRFS_I(mapping->host)->io_tree; return extent_writepages(tree, mapping, btrfs_get_extent, wbc); } static int btrfs_readpages(struct file *file, struct address_space *mapping, struct list_head *pages, unsigned nr_pages) { struct extent_io_tree *tree; tree = &BTRFS_I(mapping->host)->io_tree; return extent_readpages(tree, mapping, pages, nr_pages, btrfs_get_extent); } static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags) { struct extent_io_tree *tree; struct extent_map_tree *map; int ret; tree = &BTRFS_I(page->mapping->host)->io_tree; map = &BTRFS_I(page->mapping->host)->extent_tree; ret = try_release_extent_mapping(map, tree, page, gfp_flags); if (ret == 1) { ClearPagePrivate(page); set_page_private(page, 0); page_cache_release(page); } return ret; } static int btrfs_releasepage(struct page *page, gfp_t gfp_flags) { if (PageWriteback(page) || PageDirty(page)) return 0; return __btrfs_releasepage(page, gfp_flags & GFP_NOFS); } static void btrfs_invalidatepage(struct page *page, unsigned long offset) { struct extent_io_tree *tree; struct btrfs_ordered_extent *ordered; struct extent_state *cached_state = NULL; u64 page_start = page_offset(page); u64 page_end = page_start + PAGE_CACHE_SIZE - 1; /* * we have the page locked, so new writeback can't start, * and the dirty bit won't be cleared while we are here. * * Wait for IO on this page so that we can safely clear * the PagePrivate2 bit and do ordered accounting */ wait_on_page_writeback(page); tree = &BTRFS_I(page->mapping->host)->io_tree; if (offset) { btrfs_releasepage(page, GFP_NOFS); return; } lock_extent_bits(tree, page_start, page_end, 0, &cached_state, GFP_NOFS); ordered = btrfs_lookup_ordered_extent(page->mapping->host, page_offset(page)); if (ordered) { /* * IO on this page will never be started, so we need * to account for any ordered extents now */ clear_extent_bit(tree, page_start, page_end, EXTENT_DIRTY | EXTENT_DELALLOC | EXTENT_LOCKED | EXTENT_DO_ACCOUNTING, 1, 0, &cached_state, GFP_NOFS); /* * whoever cleared the private bit is responsible * for the finish_ordered_io */ if (TestClearPagePrivate2(page)) { btrfs_finish_ordered_io(page->mapping->host, page_start, page_end); } btrfs_put_ordered_extent(ordered); cached_state = NULL; lock_extent_bits(tree, page_start, page_end, 0, &cached_state, GFP_NOFS); } clear_extent_bit(tree, page_start, page_end, EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING, 1, 1, &cached_state, GFP_NOFS); __btrfs_releasepage(page, GFP_NOFS); ClearPageChecked(page); if (PagePrivate(page)) { ClearPagePrivate(page); set_page_private(page, 0); page_cache_release(page); } } /* * btrfs_page_mkwrite() is not allowed to change the file size as it gets * called from a page fault handler when a page is first dirtied. Hence we must * be careful to check for EOF conditions here. We set the page up correctly * for a written page which means we get ENOSPC checking when writing into * holes and correct delalloc and unwritten extent mapping on filesystems that * support these features. * * We are not allowed to take the i_mutex here so we have to play games to * protect against truncate races as the page could now be beyond EOF. Because * vmtruncate() writes the inode size before removing pages, once we have the * page lock we can determine safely if the page is beyond EOF. If it is not * beyond EOF, then the page is guaranteed safe against truncation until we * unlock the page. */ int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) { struct page *page = vmf->page; struct inode *inode = fdentry(vma->vm_file)->d_inode; struct btrfs_root *root = BTRFS_I(inode)->root; struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; struct btrfs_ordered_extent *ordered; struct extent_state *cached_state = NULL; char *kaddr; unsigned long zero_start; loff_t size; int ret; u64 page_start; u64 page_end; ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE); if (ret) { if (ret == -ENOMEM) ret = VM_FAULT_OOM; else /* -ENOSPC, -EIO, etc */ ret = VM_FAULT_SIGBUS; goto out; } ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */ again: lock_page(page); size = i_size_read(inode); page_start = page_offset(page); page_end = page_start + PAGE_CACHE_SIZE - 1; if ((page->mapping != inode->i_mapping) || (page_start >= size)) { /* page got truncated out from underneath us */ goto out_unlock; } wait_on_page_writeback(page); lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state, GFP_NOFS); set_page_extent_mapped(page); /* * we can't set the delalloc bits if there are pending ordered * extents. Drop our locks and wait for them to finish */ ordered = btrfs_lookup_ordered_extent(inode, page_start); if (ordered) { unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS); unlock_page(page); btrfs_start_ordered_extent(inode, ordered, 1); btrfs_put_ordered_extent(ordered); goto again; } /* * XXX - page_mkwrite gets called every time the page is dirtied, even * if it was already dirty, so for space accounting reasons we need to * clear any delalloc bits for the range we are fixing to save. There * is probably a better way to do this, but for now keep consistent with * prepare_pages in the normal write path. */ clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end, EXTENT_DIRTY | EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING, 0, 0, &cached_state, GFP_NOFS); ret = btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state); if (ret) { unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS); ret = VM_FAULT_SIGBUS; goto out_unlock; } ret = 0; /* page is wholly or partially inside EOF */ if (page_start + PAGE_CACHE_SIZE > size) zero_start = size & ~PAGE_CACHE_MASK; else zero_start = PAGE_CACHE_SIZE; if (zero_start != PAGE_CACHE_SIZE) { kaddr = kmap(page); memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start); flush_dcache_page(page); kunmap(page); } ClearPageChecked(page); set_page_dirty(page); SetPageUptodate(page); BTRFS_I(inode)->last_trans = root->fs_info->generation; BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid; unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS); out_unlock: if (!ret) return VM_FAULT_LOCKED; unlock_page(page); btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE); out: return ret; } static int btrfs_truncate(struct inode *inode) { struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_block_rsv *rsv; int ret; int err = 0; struct btrfs_trans_handle *trans; unsigned long nr; u64 mask = root->sectorsize - 1; ret = btrfs_truncate_page(inode->i_mapping, inode->i_size); if (ret) return ret; btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1); btrfs_ordered_update_i_size(inode, inode->i_size, NULL); /* * Yes ladies and gentelment, this is indeed ugly. The fact is we have * 3 things going on here * * 1) We need to reserve space for our orphan item and the space to * delete our orphan item. Lord knows we don't want to have a dangling * orphan item because we didn't reserve space to remove it. * * 2) We need to reserve space to update our inode. * * 3) We need to have something to cache all the space that is going to * be free'd up by the truncate operation, but also have some slack * space reserved in case it uses space during the truncate (thank you * very much snapshotting). * * And we need these to all be seperate. The fact is we can use alot of * space doing the truncate, and we have no earthly idea how much space * we will use, so we need the truncate reservation to be seperate so it * doesn't end up using space reserved for updating the inode or * removing the orphan item. We also need to be able to stop the * transaction and start a new one, which means we need to be able to * update the inode several times, and we have no idea of knowing how * many times that will be, so we can't just reserve 1 item for the * entirety of the opration, so that has to be done seperately as well. * Then there is the orphan item, which does indeed need to be held on * to for the whole operation, and we need nobody to touch this reserved * space except the orphan code. * * So that leaves us with * * 1) root->orphan_block_rsv - for the orphan deletion. * 2) rsv - for the truncate reservation, which we will steal from the * transaction reservation. * 3) fs_info->trans_block_rsv - this will have 1 items worth left for * updating the inode. */ rsv = btrfs_alloc_block_rsv(root); if (!rsv) return -ENOMEM; btrfs_add_durable_block_rsv(root->fs_info, rsv); trans = btrfs_start_transaction(root, 4); if (IS_ERR(trans)) { err = PTR_ERR(trans); goto out; } /* * Reserve space for the truncate process. Truncate should be adding * space, but if there are snapshots it may end up using space. */ ret = btrfs_truncate_reserve_metadata(trans, root, rsv); BUG_ON(ret); ret = btrfs_orphan_add(trans, inode); if (ret) { btrfs_end_transaction(trans, root); goto out; } nr = trans->blocks_used; btrfs_end_transaction(trans, root); btrfs_btree_balance_dirty(root, nr); /* * Ok so we've already migrated our bytes over for the truncate, so here * just reserve the one slot we need for updating the inode. */ trans = btrfs_start_transaction(root, 1); if (IS_ERR(trans)) { err = PTR_ERR(trans); goto out; } trans->block_rsv = rsv; /* * setattr is responsible for setting the ordered_data_close flag, * but that is only tested during the last file release. That * could happen well after the next commit, leaving a great big * window where new writes may get lost if someone chooses to write * to this file after truncating to zero * * The inode doesn't have any dirty data here, and so if we commit * this is a noop. If someone immediately starts writing to the inode * it is very likely we'll catch some of their writes in this * transaction, and the commit will find this file on the ordered * data list with good things to send down. * * This is a best effort solution, there is still a window where * using truncate to replace the contents of the file will * end up with a zero length file after a crash. */ if (inode->i_size == 0 && BTRFS_I(inode)->ordered_data_close) btrfs_add_ordered_operation(trans, root, inode); while (1) { if (!trans) { trans = btrfs_start_transaction(root, 3); if (IS_ERR(trans)) { err = PTR_ERR(trans); goto out; } ret = btrfs_truncate_reserve_metadata(trans, root, rsv); BUG_ON(ret); trans->block_rsv = rsv; } ret = btrfs_truncate_inode_items(trans, root, inode, inode->i_size, BTRFS_EXTENT_DATA_KEY); if (ret != -EAGAIN) { err = ret; break; } trans->block_rsv = &root->fs_info->trans_block_rsv; ret = btrfs_update_inode(trans, root, inode); if (ret) { err = ret; break; } nr = trans->blocks_used; btrfs_end_transaction(trans, root); trans = NULL; btrfs_btree_balance_dirty(root, nr); } if (ret == 0 && inode->i_nlink > 0) { trans->block_rsv = root->orphan_block_rsv; ret = btrfs_orphan_del(trans, inode); if (ret) err = ret; } else if (ret && inode->i_nlink > 0) { /* * Failed to do the truncate, remove us from the in memory * orphan list. */ ret = btrfs_orphan_del(NULL, inode); } trans->block_rsv = &root->fs_info->trans_block_rsv; ret = btrfs_update_inode(trans, root, inode); if (ret && !err) err = ret; nr = trans->blocks_used; ret = btrfs_end_transaction_throttle(trans, root); btrfs_btree_balance_dirty(root, nr); out: btrfs_free_block_rsv(root, rsv); if (ret && !err) err = ret; return err; } /* * create a new subvolume directory/inode (helper for the ioctl). */ int btrfs_create_subvol_root(struct btrfs_trans_handle *trans, struct btrfs_root *new_root, u64 new_dirid) { struct inode *inode; int err; u64 index = 0; inode = btrfs_new_inode(trans, new_root, NULL, "..", 2, new_dirid, new_dirid, S_IFDIR | 0700, &index); if (IS_ERR(inode)) return PTR_ERR(inode); inode->i_op = &btrfs_dir_inode_operations; inode->i_fop = &btrfs_dir_file_operations; inode->i_nlink = 1; btrfs_i_size_write(inode, 0); err = btrfs_update_inode(trans, new_root, inode); BUG_ON(err); iput(inode); return 0; } /* helper function for file defrag and space balancing. This * forces readahead on a given range of bytes in an inode */ unsigned long btrfs_force_ra(struct address_space *mapping, struct file_ra_state *ra, struct file *file, pgoff_t offset, pgoff_t last_index) { pgoff_t req_size = last_index - offset + 1; page_cache_sync_readahead(mapping, ra, file, offset, req_size); return offset + req_size; } struct inode *btrfs_alloc_inode(struct super_block *sb) { struct btrfs_inode *ei; struct inode *inode; ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS); if (!ei) return NULL; ei->root = NULL; ei->space_info = NULL; ei->generation = 0; ei->sequence = 0; ei->last_trans = 0; ei->last_sub_trans = 0; ei->logged_trans = 0; ei->delalloc_bytes = 0; ei->reserved_bytes = 0; ei->disk_i_size = 0; ei->flags = 0; ei->index_cnt = (u64)-1; ei->last_unlink_trans = 0; spin_lock_init(&ei->lock); ei->outstanding_extents = 0; ei->reserved_extents = 0; ei->ordered_data_close = 0; ei->orphan_meta_reserved = 0; ei->dummy_inode = 0; ei->in_defrag = 0; ei->force_compress = BTRFS_COMPRESS_NONE; ei->delayed_node = NULL; inode = &ei->vfs_inode; extent_map_tree_init(&ei->extent_tree); extent_io_tree_init(&ei->io_tree, &inode->i_data); extent_io_tree_init(&ei->io_failure_tree, &inode->i_data); mutex_init(&ei->log_mutex); btrfs_ordered_inode_tree_init(&ei->ordered_tree); INIT_LIST_HEAD(&ei->i_orphan); INIT_LIST_HEAD(&ei->delalloc_inodes); INIT_LIST_HEAD(&ei->ordered_operations); RB_CLEAR_NODE(&ei->rb_node); return inode; } static void btrfs_i_callback(struct rcu_head *head) { struct inode *inode = container_of(head, struct inode, i_rcu); INIT_LIST_HEAD(&inode->i_dentry); kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode)); } void btrfs_destroy_inode(struct inode *inode) { struct btrfs_ordered_extent *ordered; struct btrfs_root *root = BTRFS_I(inode)->root; WARN_ON(!list_empty(&inode->i_dentry)); WARN_ON(inode->i_data.nrpages); WARN_ON(BTRFS_I(inode)->outstanding_extents); WARN_ON(BTRFS_I(inode)->reserved_extents); /* * This can happen where we create an inode, but somebody else also * created the same inode and we need to destroy the one we already * created. */ if (!root) goto free; /* * Make sure we're properly removed from the ordered operation * lists. */ smp_mb(); if (!list_empty(&BTRFS_I(inode)->ordered_operations)) { spin_lock(&root->fs_info->ordered_extent_lock); list_del_init(&BTRFS_I(inode)->ordered_operations); spin_unlock(&root->fs_info->ordered_extent_lock); } spin_lock(&root->orphan_lock); if (!list_empty(&BTRFS_I(inode)->i_orphan)) { printk(KERN_INFO "BTRFS: inode %llu still on the orphan list\n", (unsigned long long)btrfs_ino(inode)); list_del_init(&BTRFS_I(inode)->i_orphan); } spin_unlock(&root->orphan_lock); while (1) { ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1); if (!ordered) break; else { printk(KERN_ERR "btrfs found ordered " "extent %llu %llu on inode cleanup\n", (unsigned long long)ordered->file_offset, (unsigned long long)ordered->len); btrfs_remove_ordered_extent(inode, ordered); btrfs_put_ordered_extent(ordered); btrfs_put_ordered_extent(ordered); } } inode_tree_del(inode); btrfs_drop_extent_cache(inode, 0, (u64)-1, 0); free: btrfs_remove_delayed_node(inode); call_rcu(&inode->i_rcu, btrfs_i_callback); } int btrfs_drop_inode(struct inode *inode) { struct btrfs_root *root = BTRFS_I(inode)->root; if (btrfs_root_refs(&root->root_item) == 0 && !btrfs_is_free_space_inode(root, inode)) return 1; else return generic_drop_inode(inode); } static void init_once(void *foo) { struct btrfs_inode *ei = (struct btrfs_inode *) foo; inode_init_once(&ei->vfs_inode); } void btrfs_destroy_cachep(void) { if (btrfs_inode_cachep) kmem_cache_destroy(btrfs_inode_cachep); if (btrfs_trans_handle_cachep) kmem_cache_destroy(btrfs_trans_handle_cachep); if (btrfs_transaction_cachep) kmem_cache_destroy(btrfs_transaction_cachep); if (btrfs_path_cachep) kmem_cache_destroy(btrfs_path_cachep); if (btrfs_free_space_cachep) kmem_cache_destroy(btrfs_free_space_cachep); } int btrfs_init_cachep(void) { btrfs_inode_cachep = kmem_cache_create("btrfs_inode_cache", sizeof(struct btrfs_inode), 0, SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, init_once); if (!btrfs_inode_cachep) goto fail; btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle_cache", sizeof(struct btrfs_trans_handle), 0, SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); if (!btrfs_trans_handle_cachep) goto fail; btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction_cache", sizeof(struct btrfs_transaction), 0, SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); if (!btrfs_transaction_cachep) goto fail; btrfs_path_cachep = kmem_cache_create("btrfs_path_cache", sizeof(struct btrfs_path), 0, SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); if (!btrfs_path_cachep) goto fail; btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space_cache", sizeof(struct btrfs_free_space), 0, SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); if (!btrfs_free_space_cachep) goto fail; return 0; fail: btrfs_destroy_cachep(); return -ENOMEM; } static int btrfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) { struct inode *inode = dentry->d_inode; generic_fillattr(inode, stat); stat->dev = BTRFS_I(inode)->root->anon_super.s_dev; stat->blksize = PAGE_CACHE_SIZE; stat->blocks = (inode_get_bytes(inode) + BTRFS_I(inode)->delalloc_bytes) >> 9; return 0; } /* * If a file is moved, it will inherit the cow and compression flags of the new * directory. */ static void fixup_inode_flags(struct inode *dir, struct inode *inode) { struct btrfs_inode *b_dir = BTRFS_I(dir); struct btrfs_inode *b_inode = BTRFS_I(inode); if (b_dir->flags & BTRFS_INODE_NODATACOW) b_inode->flags |= BTRFS_INODE_NODATACOW; else b_inode->flags &= ~BTRFS_INODE_NODATACOW; if (b_dir->flags & BTRFS_INODE_COMPRESS) b_inode->flags |= BTRFS_INODE_COMPRESS; else b_inode->flags &= ~BTRFS_INODE_COMPRESS; } static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry) { struct btrfs_trans_handle *trans; struct btrfs_root *root = BTRFS_I(old_dir)->root; struct btrfs_root *dest = BTRFS_I(new_dir)->root; struct inode *new_inode = new_dentry->d_inode; struct inode *old_inode = old_dentry->d_inode; struct timespec ctime = CURRENT_TIME; u64 index = 0; u64 root_objectid; int ret; u64 old_ino = btrfs_ino(old_inode); if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) return -EPERM; /* we only allow rename subvolume link between subvolumes */ if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest) return -EXDEV; if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID || (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID)) return -ENOTEMPTY; if (S_ISDIR(old_inode->i_mode) && new_inode && new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) return -ENOTEMPTY; /* * we're using rename to replace one file with another. * and the replacement file is large. Start IO on it now so * we don't add too much work to the end of the transaction */ if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size && old_inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT) filemap_flush(old_inode->i_mapping); /* close the racy window with snapshot create/destroy ioctl */ if (old_ino == BTRFS_FIRST_FREE_OBJECTID) down_read(&root->fs_info->subvol_sem); /* * We want to reserve the absolute worst case amount of items. So if * both inodes are subvols and we need to unlink them then that would * require 4 item modifications, but if they are both normal inodes it * would require 5 item modifications, so we'll assume their normal * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items * should cover the worst case number of items we'll modify. */ trans = btrfs_start_transaction(root, 20); if (IS_ERR(trans)) { ret = PTR_ERR(trans); goto out_notrans; } if (dest != root) btrfs_record_root_in_trans(trans, dest); ret = btrfs_set_inode_index(new_dir, &index); if (ret) goto out_fail; if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) { /* force full log commit if subvolume involved. */ root->fs_info->last_trans_log_full_commit = trans->transid; } else { ret = btrfs_insert_inode_ref(trans, dest, new_dentry->d_name.name, new_dentry->d_name.len, old_ino, btrfs_ino(new_dir), index); if (ret) goto out_fail; /* * this is an ugly little race, but the rename is required * to make sure that if we crash, the inode is either at the * old name or the new one. pinning the log transaction lets * us make sure we don't allow a log commit to come in after * we unlink the name but before we add the new name back in. */ btrfs_pin_log_trans(root); } /* * make sure the inode gets flushed if it is replacing * something. */ if (new_inode && new_inode->i_size && S_ISREG(old_inode->i_mode)) btrfs_add_ordered_operation(trans, root, old_inode); old_dir->i_ctime = old_dir->i_mtime = ctime; new_dir->i_ctime = new_dir->i_mtime = ctime; old_inode->i_ctime = ctime; if (old_dentry->d_parent != new_dentry->d_parent) btrfs_record_unlink_dir(trans, old_dir, old_inode, 1); if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) { root_objectid = BTRFS_I(old_inode)->root->root_key.objectid; ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid, old_dentry->d_name.name, old_dentry->d_name.len); } else { ret = __btrfs_unlink_inode(trans, root, old_dir, old_dentry->d_inode, old_dentry->d_name.name, old_dentry->d_name.len); if (!ret) ret = btrfs_update_inode(trans, root, old_inode); } BUG_ON(ret); if (new_inode) { new_inode->i_ctime = CURRENT_TIME; if (unlikely(btrfs_ino(new_inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) { root_objectid = BTRFS_I(new_inode)->location.objectid; ret = btrfs_unlink_subvol(trans, dest, new_dir, root_objectid, new_dentry->d_name.name, new_dentry->d_name.len); BUG_ON(new_inode->i_nlink == 0); } else { ret = btrfs_unlink_inode(trans, dest, new_dir, new_dentry->d_inode, new_dentry->d_name.name, new_dentry->d_name.len); } BUG_ON(ret); if (new_inode->i_nlink == 0) { ret = btrfs_orphan_add(trans, new_dentry->d_inode); BUG_ON(ret); } } fixup_inode_flags(new_dir, old_inode); ret = btrfs_add_link(trans, new_dir, old_inode, new_dentry->d_name.name, new_dentry->d_name.len, 0, index); BUG_ON(ret); if (old_ino != BTRFS_FIRST_FREE_OBJECTID) { struct dentry *parent = dget_parent(new_dentry); btrfs_log_new_name(trans, old_inode, old_dir, parent); dput(parent); btrfs_end_log_trans(root); } out_fail: btrfs_end_transaction_throttle(trans, root); out_notrans: if (old_ino == BTRFS_FIRST_FREE_OBJECTID) up_read(&root->fs_info->subvol_sem); return ret; } /* * some fairly slow code that needs optimization. This walks the list * of all the inodes with pending delalloc and forces them to disk. */ int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput) { struct list_head *head = &root->fs_info->delalloc_inodes; struct btrfs_inode *binode; struct inode *inode; if (root->fs_info->sb->s_flags & MS_RDONLY) return -EROFS; spin_lock(&root->fs_info->delalloc_lock); while (!list_empty(head)) { binode = list_entry(head->next, struct btrfs_inode, delalloc_inodes); inode = igrab(&binode->vfs_inode); if (!inode) list_del_init(&binode->delalloc_inodes); spin_unlock(&root->fs_info->delalloc_lock); if (inode) { filemap_flush(inode->i_mapping); if (delay_iput) btrfs_add_delayed_iput(inode); else iput(inode); } cond_resched(); spin_lock(&root->fs_info->delalloc_lock); } spin_unlock(&root->fs_info->delalloc_lock); /* the filemap_flush will queue IO into the worker threads, but * we have to make sure the IO is actually started and that * ordered extents get created before we return */ atomic_inc(&root->fs_info->async_submit_draining); while (atomic_read(&root->fs_info->nr_async_submits) || atomic_read(&root->fs_info->async_delalloc_pages)) { wait_event(root->fs_info->async_submit_wait, (atomic_read(&root->fs_info->nr_async_submits) == 0 && atomic_read(&root->fs_info->async_delalloc_pages) == 0)); } atomic_dec(&root->fs_info->async_submit_draining); return 0; } static int btrfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname) { struct btrfs_trans_handle *trans; struct btrfs_root *root = BTRFS_I(dir)->root; struct btrfs_path *path; struct btrfs_key key; struct inode *inode = NULL; int err; int drop_inode = 0; u64 objectid; u64 index = 0 ; int name_len; int datasize; unsigned long ptr; struct btrfs_file_extent_item *ei; struct extent_buffer *leaf; unsigned long nr = 0; name_len = strlen(symname) + 1; if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root)) return -ENAMETOOLONG; /* * 2 items for inode item and ref * 2 items for dir items * 1 item for xattr if selinux is on */ trans = btrfs_start_transaction(root, 5); if (IS_ERR(trans)) return PTR_ERR(trans); err = btrfs_find_free_ino(root, &objectid); if (err) goto out_unlock; inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, dentry->d_name.len, btrfs_ino(dir), objectid, S_IFLNK|S_IRWXUGO, &index); if (IS_ERR(inode)) { err = PTR_ERR(inode); goto out_unlock; } err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); if (err) { drop_inode = 1; goto out_unlock; } err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index); if (err) drop_inode = 1; else { inode->i_mapping->a_ops = &btrfs_aops; inode->i_mapping->backing_dev_info = &root->fs_info->bdi; inode->i_fop = &btrfs_file_operations; inode->i_op = &btrfs_file_inode_operations; BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; } if (drop_inode) goto out_unlock; path = btrfs_alloc_path(); BUG_ON(!path); key.objectid = btrfs_ino(inode); key.offset = 0; btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY); datasize = btrfs_file_extent_calc_inline_size(name_len); err = btrfs_insert_empty_item(trans, root, path, &key, datasize); if (err) { drop_inode = 1; btrfs_free_path(path); goto out_unlock; } leaf = path->nodes[0]; ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); btrfs_set_file_extent_generation(leaf, ei, trans->transid); btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE); btrfs_set_file_extent_encryption(leaf, ei, 0); btrfs_set_file_extent_compression(leaf, ei, 0); btrfs_set_file_extent_other_encoding(leaf, ei, 0); btrfs_set_file_extent_ram_bytes(leaf, ei, name_len); ptr = btrfs_file_extent_inline_start(ei); write_extent_buffer(leaf, symname, ptr, name_len); btrfs_mark_buffer_dirty(leaf); btrfs_free_path(path); inode->i_op = &btrfs_symlink_inode_operations; inode->i_mapping->a_ops = &btrfs_symlink_aops; inode->i_mapping->backing_dev_info = &root->fs_info->bdi; inode_set_bytes(inode, name_len); btrfs_i_size_write(inode, name_len - 1); err = btrfs_update_inode(trans, root, inode); if (err) drop_inode = 1; out_unlock: nr = trans->blocks_used; btrfs_end_transaction_throttle(trans, root); if (drop_inode) { inode_dec_link_count(inode); iput(inode); } btrfs_btree_balance_dirty(root, nr); return err; } static int __btrfs_prealloc_file_range(struct inode *inode, int mode, u64 start, u64 num_bytes, u64 min_size, loff_t actual_len, u64 *alloc_hint, struct btrfs_trans_handle *trans) { struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_key ins; u64 cur_offset = start; u64 i_size; int ret = 0; bool own_trans = true; if (trans) own_trans = false; while (num_bytes > 0) { if (own_trans) { trans = btrfs_start_transaction(root, 3); if (IS_ERR(trans)) { ret = PTR_ERR(trans); break; } } ret = btrfs_reserve_extent(trans, root, num_bytes, min_size, 0, *alloc_hint, (u64)-1, &ins, 1); if (ret) { if (own_trans) btrfs_end_transaction(trans, root); break; } ret = insert_reserved_file_extent(trans, inode, cur_offset, ins.objectid, ins.offset, ins.offset, ins.offset, 0, 0, 0, BTRFS_FILE_EXTENT_PREALLOC); BUG_ON(ret); btrfs_drop_extent_cache(inode, cur_offset, cur_offset + ins.offset -1, 0); num_bytes -= ins.offset; cur_offset += ins.offset; *alloc_hint = ins.objectid + ins.offset; inode->i_ctime = CURRENT_TIME; BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC; if (!(mode & FALLOC_FL_KEEP_SIZE) && (actual_len > inode->i_size) && (cur_offset > inode->i_size)) { if (cur_offset > actual_len) i_size = actual_len; else i_size = cur_offset; i_size_write(inode, i_size); btrfs_ordered_update_i_size(inode, i_size, NULL); } ret = btrfs_update_inode(trans, root, inode); BUG_ON(ret); if (own_trans) btrfs_end_transaction(trans, root); } return ret; } int btrfs_prealloc_file_range(struct inode *inode, int mode, u64 start, u64 num_bytes, u64 min_size, loff_t actual_len, u64 *alloc_hint) { return __btrfs_prealloc_file_range(inode, mode, start, num_bytes, min_size, actual_len, alloc_hint, NULL); } int btrfs_prealloc_file_range_trans(struct inode *inode, struct btrfs_trans_handle *trans, int mode, u64 start, u64 num_bytes, u64 min_size, loff_t actual_len, u64 *alloc_hint) { return __btrfs_prealloc_file_range(inode, mode, start, num_bytes, min_size, actual_len, alloc_hint, trans); } static int btrfs_set_page_dirty(struct page *page) { return __set_page_dirty_nobuffers(page); } static int btrfs_permission(struct inode *inode, int mask, unsigned int flags) { struct btrfs_root *root = BTRFS_I(inode)->root; if (btrfs_root_readonly(root) && (mask & MAY_WRITE)) return -EROFS; if ((BTRFS_I(inode)->flags & BTRFS_INODE_READONLY) && (mask & MAY_WRITE)) return -EACCES; return generic_permission(inode, mask, flags, btrfs_check_acl); } static const struct inode_operations btrfs_dir_inode_operations = { .getattr = btrfs_getattr, .lookup = btrfs_lookup, .create = btrfs_create, .unlink = btrfs_unlink, .link = btrfs_link, .mkdir = btrfs_mkdir, .rmdir = btrfs_rmdir, .rename = btrfs_rename, .symlink = btrfs_symlink, .setattr = btrfs_setattr, .mknod = btrfs_mknod, .setxattr = btrfs_setxattr, .getxattr = btrfs_getxattr, .listxattr = btrfs_listxattr, .removexattr = btrfs_removexattr, .permission = btrfs_permission, }; static const struct inode_operations btrfs_dir_ro_inode_operations = { .lookup = btrfs_lookup, .permission = btrfs_permission, }; static const struct file_operations btrfs_dir_file_operations = { .llseek = generic_file_llseek, .read = generic_read_dir, .readdir = btrfs_real_readdir, .unlocked_ioctl = btrfs_ioctl, #ifdef CONFIG_COMPAT .compat_ioctl = btrfs_ioctl, #endif .release = btrfs_release_file, .fsync = btrfs_sync_file, }; static struct extent_io_ops btrfs_extent_io_ops = { .fill_delalloc = run_delalloc_range, .submit_bio_hook = btrfs_submit_bio_hook, .merge_bio_hook = btrfs_merge_bio_hook, .readpage_end_io_hook = btrfs_readpage_end_io_hook, .writepage_end_io_hook = btrfs_writepage_end_io_hook, .writepage_start_hook = btrfs_writepage_start_hook, .readpage_io_failed_hook = btrfs_io_failed_hook, .set_bit_hook = btrfs_set_bit_hook, .clear_bit_hook = btrfs_clear_bit_hook, .merge_extent_hook = btrfs_merge_extent_hook, .split_extent_hook = btrfs_split_extent_hook, }; /* * btrfs doesn't support the bmap operation because swapfiles * use bmap to make a mapping of extents in the file. They assume * these extents won't change over the life of the file and they * use the bmap result to do IO directly to the drive. * * the btrfs bmap call would return logical addresses that aren't * suitable for IO and they also will change frequently as COW * operations happen. So, swapfile + btrfs == corruption. * * For now we're avoiding this by dropping bmap. */ static const struct address_space_operations btrfs_aops = { .readpage = btrfs_readpage, .writepage = btrfs_writepage, .writepages = btrfs_writepages, .readpages = btrfs_readpages, .direct_IO = btrfs_direct_IO, .invalidatepage = btrfs_invalidatepage, .releasepage = btrfs_releasepage, .set_page_dirty = btrfs_set_page_dirty, .error_remove_page = generic_error_remove_page, }; static const struct address_space_operations btrfs_symlink_aops = { .readpage = btrfs_readpage, .writepage = btrfs_writepage, .invalidatepage = btrfs_invalidatepage, .releasepage = btrfs_releasepage, }; static const struct inode_operations btrfs_file_inode_operations = { .getattr = btrfs_getattr, .setattr = btrfs_setattr, .setxattr = btrfs_setxattr, .getxattr = btrfs_getxattr, .listxattr = btrfs_listxattr, .removexattr = btrfs_removexattr, .permission = btrfs_permission, .fiemap = btrfs_fiemap, }; static const struct inode_operations btrfs_special_inode_operations = { .getattr = btrfs_getattr, .setattr = btrfs_setattr, .permission = btrfs_permission, .setxattr = btrfs_setxattr, .getxattr = btrfs_getxattr, .listxattr = btrfs_listxattr, .removexattr = btrfs_removexattr, }; static const struct inode_operations btrfs_symlink_inode_operations = { .readlink = generic_readlink, .follow_link = page_follow_link_light, .put_link = page_put_link, .getattr = btrfs_getattr, .permission = btrfs_permission, .setxattr = btrfs_setxattr, .getxattr = btrfs_getxattr, .listxattr = btrfs_listxattr, .removexattr = btrfs_removexattr, }; const struct dentry_operations btrfs_dentry_operations = { .d_delete = btrfs_dentry_delete, };