diff options
| -rw-r--r-- | fs/btrfs/Makefile | 2 | ||||
| -rw-r--r-- | fs/btrfs/btrfs_inode.h | 9 | ||||
| -rw-r--r-- | fs/btrfs/direct-io.c | 1052 | ||||
| -rw-r--r-- | fs/btrfs/direct-io.h | 14 | ||||
| -rw-r--r-- | fs/btrfs/file.c | 287 | ||||
| -rw-r--r-- | fs/btrfs/file.h | 2 | ||||
| -rw-r--r-- | fs/btrfs/inode.c | 784 | ||||
| -rw-r--r-- | fs/btrfs/super.c | 4 |
8 files changed, 1095 insertions, 1059 deletions
diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile index 50b19d15e956..87617f2968bc 100644 --- a/fs/btrfs/Makefile +++ b/fs/btrfs/Makefile @@ -33,7 +33,7 @@ btrfs-y += super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \ uuid-tree.o props.o free-space-tree.o tree-checker.o space-info.o \ block-rsv.o delalloc-space.o block-group.o discard.o reflink.o \ subpage.o tree-mod-log.o extent-io-tree.o fs.o messages.o bio.o \ - lru_cache.o raid-stripe-tree.o fiemap.o + lru_cache.o raid-stripe-tree.o fiemap.o direct-io.o btrfs-$(CONFIG_BTRFS_FS_POSIX_ACL) += acl.o btrfs-$(CONFIG_BTRFS_FS_REF_VERIFY) += ref-verify.o diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h index 8b45d7e85d86..3056c8aed8ef 100644 --- a/fs/btrfs/btrfs_inode.h +++ b/fs/btrfs/btrfs_inode.h @@ -610,10 +610,6 @@ ssize_t btrfs_encoded_read(struct kiocb *iocb, struct iov_iter *iter, ssize_t btrfs_do_encoded_write(struct kiocb *iocb, struct iov_iter *from, const struct btrfs_ioctl_encoded_io_args *encoded); -ssize_t btrfs_dio_read(struct kiocb *iocb, struct iov_iter *iter, - size_t done_before); -struct iomap_dio *btrfs_dio_write(struct kiocb *iocb, struct iov_iter *iter, - size_t done_before); struct btrfs_inode *btrfs_find_first_inode(struct btrfs_root *root, u64 min_ino); extern const struct dentry_operations btrfs_dentry_operations; @@ -630,5 +626,10 @@ void btrfs_inode_unlock(struct btrfs_inode *inode, unsigned int ilock_flags); void btrfs_update_inode_bytes(struct btrfs_inode *inode, const u64 add_bytes, const u64 del_bytes); void btrfs_assert_inode_range_clean(struct btrfs_inode *inode, u64 start, u64 end); +u64 btrfs_get_extent_allocation_hint(struct btrfs_inode *inode, u64 start, + u64 num_bytes); +struct extent_map *btrfs_create_io_em(struct btrfs_inode *inode, u64 start, + const struct btrfs_file_extent *file_extent, + int type); #endif diff --git a/fs/btrfs/direct-io.c b/fs/btrfs/direct-io.c new file mode 100644 index 000000000000..f9fb2db6a1e4 --- /dev/null +++ b/fs/btrfs/direct-io.c @@ -0,0 +1,1052 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/fsverity.h> +#include <linux/iomap.h> +#include "ctree.h" +#include "delalloc-space.h" +#include "direct-io.h" +#include "extent-tree.h" +#include "file.h" +#include "fs.h" +#include "transaction.h" +#include "volumes.h" + +struct btrfs_dio_data { + ssize_t submitted; + struct extent_changeset *data_reserved; + struct btrfs_ordered_extent *ordered; + bool data_space_reserved; + bool nocow_done; +}; + +struct btrfs_dio_private { + /* Range of I/O */ + u64 file_offset; + u32 bytes; + + /* This must be last */ + struct btrfs_bio bbio; +}; + +static struct bio_set btrfs_dio_bioset; + +static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend, + struct extent_state **cached_state, + unsigned int iomap_flags) +{ + const bool writing = (iomap_flags & IOMAP_WRITE); + const bool nowait = (iomap_flags & IOMAP_NOWAIT); + struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; + struct btrfs_ordered_extent *ordered; + int ret = 0; + + while (1) { + if (nowait) { + if (!try_lock_extent(io_tree, lockstart, lockend, + cached_state)) + return -EAGAIN; + } else { + lock_extent(io_tree, lockstart, lockend, cached_state); + } + /* + * We're concerned with the entire range that we're going to be + * doing DIO to, so we need to make sure there's no ordered + * extents in this range. + */ + ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), lockstart, + lockend - lockstart + 1); + + /* + * We need to make sure there are no buffered pages in this + * range either, we could have raced between the invalidate in + * generic_file_direct_write and locking the extent. The + * invalidate needs to happen so that reads after a write do not + * get stale data. + */ + if (!ordered && + (!writing || !filemap_range_has_page(inode->i_mapping, + lockstart, lockend))) + break; + + unlock_extent(io_tree, lockstart, lockend, cached_state); + + if (ordered) { + if (nowait) { + btrfs_put_ordered_extent(ordered); + ret = -EAGAIN; + break; + } + /* + * If we are doing a DIO read and the ordered extent we + * found is for a buffered write, we can not wait for it + * to complete and retry, because if we do so we can + * deadlock with concurrent buffered writes on page + * locks. This happens only if our DIO read covers more + * than one extent map, if at this point has already + * created an ordered extent for a previous extent map + * and locked its range in the inode's io tree, and a + * concurrent write against that previous extent map's + * range and this range started (we unlock the ranges + * in the io tree only when the bios complete and + * buffered writes always lock pages before attempting + * to lock range in the io tree). + */ + if (writing || + test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags)) + btrfs_start_ordered_extent(ordered); + else + ret = nowait ? -EAGAIN : -ENOTBLK; + btrfs_put_ordered_extent(ordered); + } else { + /* + * We could trigger writeback for this range (and wait + * for it to complete) and then invalidate the pages for + * this range (through invalidate_inode_pages2_range()), + * but that can lead us to a deadlock with a concurrent + * call to readahead (a buffered read or a defrag call + * triggered a readahead) on a page lock due to an + * ordered dio extent we created before but did not have + * yet a corresponding bio submitted (whence it can not + * complete), which makes readahead wait for that + * ordered extent to complete while holding a lock on + * that page. + */ + ret = nowait ? -EAGAIN : -ENOTBLK; + } + + if (ret) + break; + + cond_resched(); + } + + return ret; +} + +static struct extent_map *btrfs_create_dio_extent(struct btrfs_inode *inode, + struct btrfs_dio_data *dio_data, + const u64 start, + const struct btrfs_file_extent *file_extent, + const int type) +{ + struct extent_map *em = NULL; + struct btrfs_ordered_extent *ordered; + + if (type != BTRFS_ORDERED_NOCOW) { + em = btrfs_create_io_em(inode, start, file_extent, type); + if (IS_ERR(em)) + goto out; + } + + ordered = btrfs_alloc_ordered_extent(inode, start, file_extent, + (1 << type) | + (1 << BTRFS_ORDERED_DIRECT)); + if (IS_ERR(ordered)) { + if (em) { + free_extent_map(em); + btrfs_drop_extent_map_range(inode, start, + start + file_extent->num_bytes - 1, false); + } + em = ERR_CAST(ordered); + } else { + ASSERT(!dio_data->ordered); + dio_data->ordered = ordered; + } + out: + + return em; +} + +static struct extent_map *btrfs_new_extent_direct(struct btrfs_inode *inode, + struct btrfs_dio_data *dio_data, + u64 start, u64 len) +{ + struct btrfs_root *root = inode->root; + struct btrfs_fs_info *fs_info = root->fs_info; + struct btrfs_file_extent file_extent; + struct extent_map *em; + struct btrfs_key ins; + u64 alloc_hint; + int ret; + + alloc_hint = btrfs_get_extent_allocation_hint(inode, start, len); +again: + ret = btrfs_reserve_extent(root, len, len, fs_info->sectorsize, + 0, alloc_hint, &ins, 1, 1); + if (ret == -EAGAIN) { + ASSERT(btrfs_is_zoned(fs_info)); + wait_on_bit_io(&inode->root->fs_info->flags, BTRFS_FS_NEED_ZONE_FINISH, + TASK_UNINTERRUPTIBLE); + goto again; + } + if (ret) + return ERR_PTR(ret); + + file_extent.disk_bytenr = ins.objectid; + file_extent.disk_num_bytes = ins.offset; + file_extent.num_bytes = ins.offset; + file_extent.ram_bytes = ins.offset; + file_extent.offset = 0; + file_extent.compression = BTRFS_COMPRESS_NONE; + em = btrfs_create_dio_extent(inode, dio_data, start, &file_extent, + BTRFS_ORDERED_REGULAR); + btrfs_dec_block_group_reservations(fs_info, ins.objectid); + if (IS_ERR(em)) + btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, + 1); + + return em; +} + +static int btrfs_get_blocks_direct_write(struct extent_map **map, + struct inode *inode, + struct btrfs_dio_data *dio_data, + u64 start, u64 *lenp, + unsigned int iomap_flags) +{ + const bool nowait = (iomap_flags & IOMAP_NOWAIT); + struct btrfs_fs_info *fs_info = inode_to_fs_info(inode); + struct btrfs_file_extent file_extent; + struct extent_map *em = *map; + int type; + u64 block_start; + struct btrfs_block_group *bg; + bool can_nocow = false; + bool space_reserved = false; + u64 len = *lenp; + u64 prev_len; + int ret = 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 ((em->flags & EXTENT_FLAG_PREALLOC) || + ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) && + em->disk_bytenr != EXTENT_MAP_HOLE)) { + if (em->flags & EXTENT_FLAG_PREALLOC) + type = BTRFS_ORDERED_PREALLOC; + else + type = BTRFS_ORDERED_NOCOW; + len = min(len, em->len - (start - em->start)); + block_start = extent_map_block_start(em) + (start - em->start); + + if (can_nocow_extent(inode, start, &len, + &file_extent, false, false) == 1) { + bg = btrfs_inc_nocow_writers(fs_info, block_start); + if (bg) + can_nocow = true; + } + } + + prev_len = len; + if (can_nocow) { + struct extent_map *em2; + + /* We can NOCOW, so only need to reserve metadata space. */ + ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode), len, len, + nowait); + if (ret < 0) { + /* Our caller expects us to free the input extent map. */ + free_extent_map(em); + *map = NULL; + btrfs_dec_nocow_writers(bg); + if (nowait && (ret == -ENOSPC || ret == -EDQUOT)) + ret = -EAGAIN; + goto out; + } + space_reserved = true; + + em2 = btrfs_create_dio_extent(BTRFS_I(inode), dio_data, start, + &file_extent, type); + btrfs_dec_nocow_writers(bg); + if (type == BTRFS_ORDERED_PREALLOC) { + free_extent_map(em); + *map = em2; + em = em2; + } + + if (IS_ERR(em2)) { + ret = PTR_ERR(em2); + goto out; + } + + dio_data->nocow_done = true; + } else { + /* Our caller expects us to free the input extent map. */ + free_extent_map(em); + *map = NULL; + + if (nowait) { + ret = -EAGAIN; + goto out; + } + + /* + * If we could not allocate data space before locking the file + * range and we can't do a NOCOW write, then we have to fail. + */ + if (!dio_data->data_space_reserved) { + ret = -ENOSPC; + goto out; + } + + /* + * We have to COW and we have already reserved data space before, + * so now we reserve only metadata. + */ + ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode), len, len, + false); + if (ret < 0) + goto out; + space_reserved = true; + + em = btrfs_new_extent_direct(BTRFS_I(inode), dio_data, start, len); + if (IS_ERR(em)) { + ret = PTR_ERR(em); + goto out; + } + *map = em; + len = min(len, em->len - (start - em->start)); + if (len < prev_len) + btrfs_delalloc_release_metadata(BTRFS_I(inode), + prev_len - len, true); + } + + /* + * We have created our ordered extent, so we can now release our reservation + * for an outstanding extent. + */ + btrfs_delalloc_release_extents(BTRFS_I(inode), prev_len); + + /* + * Need to update the i_size under the extent lock so buffered + * readers will get the updated i_size when we unlock. + */ + if (start + len > i_size_read(inode)) + i_size_write(inode, start + len); +out: + if (ret && space_reserved) { + btrfs_delalloc_release_extents(BTRFS_I(inode), len); + btrfs_delalloc_release_metadata(BTRFS_I(inode), len, true); + } + *lenp = len; + return ret; +} + +static int btrfs_dio_iomap_begin(struct inode *inode, loff_t start, + loff_t length, unsigned int flags, struct iomap *iomap, + struct iomap *srcmap) +{ + struct iomap_iter *iter = container_of(iomap, struct iomap_iter, iomap); + struct btrfs_fs_info *fs_info = inode_to_fs_info(inode); + struct extent_map *em; + struct extent_state *cached_state = NULL; + struct btrfs_dio_data *dio_data = iter->private; + u64 lockstart, lockend; + const bool write = !!(flags & IOMAP_WRITE); + int ret = 0; + u64 len = length; + const u64 data_alloc_len = length; + bool unlock_extents = false; + + /* + * We could potentially fault if we have a buffer > PAGE_SIZE, and if + * we're NOWAIT we may submit a bio for a partial range and return + * EIOCBQUEUED, which would result in an errant short read. + * + * The best way to handle this would be to allow for partial completions + * of iocb's, so we could submit the partial bio, return and fault in + * the rest of the pages, and then submit the io for the rest of the + * range. However we don't have that currently, so simply return + * -EAGAIN at this point so that the normal path is used. + */ + if (!write && (flags & IOMAP_NOWAIT) && length > PAGE_SIZE) + return -EAGAIN; + + /* + * Cap the size of reads to that usually seen in buffered I/O as we need + * to allocate a contiguous array for the checksums. + */ + if (!write) + len = min_t(u64, len, fs_info->sectorsize * BTRFS_MAX_BIO_SECTORS); + + lockstart = start; + lockend = start + len - 1; + + /* + * iomap_dio_rw() only does filemap_write_and_wait_range(), which isn't + * enough if we've written compressed pages to this area, so we need to + * flush the dirty pages again to make absolutely sure that any + * outstanding dirty pages are on disk - the first flush only starts + * compression on the data, while keeping the pages locked, so by the + * time the second flush returns we know bios for the compressed pages + * were submitted and finished, and the pages no longer under writeback. + * + * If we have a NOWAIT request and we have any pages in the range that + * are locked, likely due to compression still in progress, we don't want + * to block on page locks. We also don't want to block on pages marked as + * dirty or under writeback (same as for the non-compression case). + * iomap_dio_rw() did the same check, but after that and before we got + * here, mmap'ed writes may have happened or buffered reads started + * (readpage() and readahead(), which lock pages), as we haven't locked + * the file range yet. + */ + if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, + &BTRFS_I(inode)->runtime_flags)) { + if (flags & IOMAP_NOWAIT) { + if (filemap_range_needs_writeback(inode->i_mapping, + lockstart, lockend)) + return -EAGAIN; + } else { + ret = filemap_fdatawrite_range(inode->i_mapping, start, + start + length - 1); + if (ret) + return ret; + } + } + + memset(dio_data, 0, sizeof(*dio_data)); + + /* + * We always try to allocate data space and must do it before locking + * the file range, to avoid deadlocks with concurrent writes to the same + * range if the range has several extents and the writes don't expand the + * current i_size (the inode lock is taken in shared mode). If we fail to + * allocate data space here we continue and later, after locking the + * file range, we fail with ENOSPC only if we figure out we can not do a + * NOCOW write. + */ + if (write && !(flags & IOMAP_NOWAIT)) { + ret = btrfs_check_data_free_space(BTRFS_I(inode), + &dio_data->data_reserved, + start, data_alloc_len, false); + if (!ret) + dio_data->data_space_reserved = true; + else if (ret && !(BTRFS_I(inode)->flags & + (BTRFS_INODE_NODATACOW | BTRFS_INODE_PREALLOC))) + goto err; + } + + /* + * If this errors out it's because we couldn't invalidate pagecache for + * this range and we need to fallback to buffered IO, or we are doing a + * NOWAIT read/write and we need to block. + */ + ret = lock_extent_direct(inode, lockstart, lockend, &cached_state, flags); + if (ret < 0) + goto err; + + em = btrfs_get_extent(BTRFS_I(inode), NULL, start, len); + if (IS_ERR(em)) { + ret = PTR_ERR(em); + goto unlock_err; + } + + /* + * 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 that's 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 (extent_map_is_compressed(em) || em->disk_bytenr == EXTENT_MAP_INLINE) { + free_extent_map(em); + /* + * If we are in a NOWAIT context, return -EAGAIN in order to + * fallback to buffered IO. This is not only because we can + * block with buffered IO (no support for NOWAIT semantics at + * the moment) but also to avoid returning short reads to user + * space - this happens if we were able to read some data from + * previous non-compressed extents and then when we fallback to + * buffered IO, at btrfs_file_read_iter() by calling + * filemap_read(), we fail to fault in pages for the read buffer, + * in which case filemap_read() returns a short read (the number + * of bytes previously read is > 0, so it does not return -EFAULT). + */ + ret = (flags & IOMAP_NOWAIT) ? -EAGAIN : -ENOTBLK; + goto unlock_err; + } + + len = min(len, em->len - (start - em->start)); + + /* + * If we have a NOWAIT request and the range contains multiple extents + * (or a mix of extents and holes), then we return -EAGAIN to make the + * caller fallback to a context where it can do a blocking (without + * NOWAIT) request. This way we avoid doing partial IO and returning + * success to the caller, which is not optimal for writes and for reads + * it can result in unexpected behaviour for an application. + * + * When doing a read, because we use IOMAP_DIO_PARTIAL when calling + * iomap_dio_rw(), we can end up returning less data then what the caller + * asked for, resulting in an unexpected, and incorrect, short read. + * That is, the caller asked to read N bytes and we return less than that, + * which is wrong unless we are crossing EOF. This happens if we get a + * page fault error when trying to fault in pages for the buffer that is + * associated to the struct iov_iter passed to iomap_dio_rw(), and we + * have previously submitted bios for other extents in the range, in + * which case iomap_dio_rw() may return us EIOCBQUEUED if not all of + * those bios have completed by the time we get the page fault error, + * which we return back to our caller - we should only return EIOCBQUEUED + * after we have submitted bios for all the extents in the range. + */ + if ((flags & IOMAP_NOWAIT) && len < length) { + free_extent_map(em); + ret = -EAGAIN; + goto unlock_err; + } + + if (write) { + ret = btrfs_get_blocks_direct_write(&em, inode, dio_data, + start, &len, flags); + if (ret < 0) + goto unlock_err; + unlock_extents = true; + /* Recalc len in case the new em is smaller than requested */ + len = min(len, em->len - (start - em->start)); + if (dio_data->data_space_reserved) { + u64 release_offset; + u64 release_len = 0; + + if (dio_data->nocow_done) { + release_offset = start; + release_len = data_alloc_len; + } else if (len < data_alloc_len) { + release_offset = start + len; + release_len = data_alloc_len - len; + } + + if (release_len > 0) + btrfs_free_reserved_data_space(BTRFS_I(inode), + dio_data->data_reserved, + release_offset, + release_len); + } + } else { + /* + * We need to unlock only the end area that we aren't using. + * The rest is going to be unlocked by the endio routine. + */ + lockstart = start + len; + if (lockstart < lockend) + unlock_extents = true; + } + + if (unlock_extents) + unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend, + &cached_state); + else + free_extent_state(cached_state); + + /* + * Translate extent map information to iomap. + * We trim the extents (and move the addr) even though iomap code does + * that, since we have locked only the parts we are performing I/O in. + */ + if ((em->disk_bytenr == EXTENT_MAP_HOLE) || + ((em->flags & EXTENT_FLAG_PREALLOC) && !write)) { + iomap->addr = IOMAP_NULL_ADDR; + iomap->type = IOMAP_HOLE; + } else { + iomap->addr = extent_map_block_start(em) + (start - em->start); + iomap->type = IOMAP_MAPPED; + } + iomap->offset = start; + iomap->bdev = fs_info->fs_devices->latest_dev->bdev; + iomap->length = len; + free_extent_map(em); + + return 0; + +unlock_err: + unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend, + &cached_state); +err: + if (dio_data->data_space_reserved) { + btrfs_free_reserved_data_space(BTRFS_I(inode), + dio_data->data_reserved, + start, data_alloc_len); + extent_changeset_free(dio_data->data_reserved); + } + + return ret; +} + +static int btrfs_dio_iomap_end(struct inode *inode, loff_t pos, loff_t length, + ssize_t written, unsigned int flags, struct iomap *iomap) +{ + struct iomap_iter *iter = container_of(iomap, struct iomap_iter, iomap); + struct btrfs_dio_data *dio_data = iter->private; + size_t submitted = dio_data->submitted; + const bool write = !!(flags & IOMAP_WRITE); + int ret = 0; + + if (!write && (iomap->type == IOMAP_HOLE)) { + /* If reading from a hole, unlock and return */ + unlock_extent(&BTRFS_I(inode)->io_tree, pos, pos + length - 1, + NULL); + return 0; + } + + if (submitted < length) { + pos += submitted; + length -= submitted; + if (write) + btrfs_finish_ordered_extent(dio_data->ordered, NULL, + pos, length, false); + else + unlock_extent(&BTRFS_I(inode)->io_tree, pos, + pos + length - 1, NULL); + ret = -ENOTBLK; + } + if (write) { + btrfs_put_ordered_extent(dio_data->ordered); + dio_data->ordered = NULL; + } + + if (write) + extent_changeset_free(dio_data->data_reserved); + return ret; +} + +static void btrfs_dio_end_io(struct btrfs_bio *bbio) +{ + struct btrfs_dio_private *dip = + container_of(bbio, struct btrfs_dio_private, bbio); + struct btrfs_inode *inode = bbio->inode; + struct bio *bio = &bbio->bio; + + if (bio->bi_status) { + btrfs_warn(inode->root->fs_info, + "direct IO failed ino %llu op 0x%0x offset %#llx len %u err no %d", + btrfs_ino(inode), bio->bi_opf, + dip->file_offset, dip->bytes, bio->bi_status); + } + + if (btrfs_op(bio) == BTRFS_MAP_WRITE) { + btrfs_finish_ordered_extent(bbio->ordered, NULL, + dip->file_offset, dip->bytes, + !bio->bi_status); + } else { + unlock_extent(&inode->io_tree, dip->file_offset, + dip->file_offset + dip->bytes - 1, NULL); + } + + bbio->bio.bi_private = bbio->private; + iomap_dio_bio_end_io(bio); +} + +static int btrfs_extract_ordered_extent(struct btrfs_bio *bbio, + struct btrfs_ordered_extent *ordered) +{ + u64 start = (u64)bbio->bio.bi_iter.bi_sector << SECTOR_SHIFT; + u64 len = bbio->bio.bi_iter.bi_size; + struct btrfs_ordered_extent *new; + int ret; + + /* Must always be called for the beginning of an ordered extent. */ + if (WARN_ON_ONCE(start != ordered->disk_bytenr)) + return -EINVAL; + + /* No need to split if the ordered extent covers the entire bio. */ + if (ordered->disk_num_bytes == len) { + refcount_inc(&ordered->refs); + bbio->ordered = ordered; + return 0; + } + + /* + * Don't split the extent_map for NOCOW extents, as we're writing into + * a pre-existing one. + */ + if (!test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags)) { + ret = split_extent_map(bbio->inode, bbio->file_offset, + ordered->num_bytes, len, + ordered->disk_bytenr); + if (ret) + return ret; + } + + new = btrfs_split_ordered_extent(ordered, len); + if (IS_ERR(new)) + return PTR_ERR(new); + bbio->ordered = new; + return 0; +} + +static void btrfs_dio_submit_io(const struct iomap_iter *iter, struct bio *bio, + loff_t file_offset) +{ + struct btrfs_bio *bbio = btrfs_bio(bio); + struct btrfs_dio_private *dip = + container_of(bbio, struct btrfs_dio_private, bbio); + struct btrfs_dio_data *dio_data = iter->private; + + btrfs_bio_init(bbio, BTRFS_I(iter->inode)->root->fs_info, + btrfs_dio_end_io, bio->bi_private); + bbio->inode = BTRFS_I(iter->inode); + bbio->file_offset = file_offset; + + dip->file_offset = file_offset; + dip->bytes = bio->bi_iter.bi_size; + + dio_data->submitted += bio->bi_iter.bi_size; + + /* + * Check if we are doing a partial write. If we are, we need to split + * the ordered extent to match the submitted bio. Hang on to the + * remaining unfinishable ordered_extent in dio_data so that it can be + * cancelled in iomap_end to avoid a deadlock wherein faulting the + * remaining pages is blocked on the outstanding ordered extent. + */ + if (iter->flags & IOMAP_WRITE) { + int ret; + + ret = btrfs_extract_ordered_extent(bbio, dio_data->ordered); + if (ret) { + btrfs_finish_ordered_extent(dio_data->ordered, NULL, + file_offset, dip->bytes, + !ret); + bio->bi_status = errno_to_blk_status(ret); + iomap_dio_bio_end_io(bio); + return; + } + } + + btrfs_submit_bio(bbio, 0); +} + +static const struct iomap_ops btrfs_dio_iomap_ops = { + .iomap_begin = btrfs_dio_iomap_begin, + .iomap_end = btrfs_dio_iomap_end, +}; + +static const struct iomap_dio_ops btrfs_dio_ops = { + .submit_io = btrfs_dio_submit_io, + .bio_set = &btrfs_dio_bioset, +}; + +static ssize_t btrfs_dio_read(struct kiocb *iocb, struct iov_iter *iter, + size_t done_before) +{ + struct btrfs_dio_data data = { 0 }; + + return iomap_dio_rw(iocb, iter, &btrfs_dio_iomap_ops, &btrfs_dio_ops, + IOMAP_DIO_PARTIAL, &data, done_before); +} + +static struct iomap_dio *btrfs_dio_write(struct kiocb *iocb, struct iov_iter *iter, + size_t done_before) +{ + struct btrfs_dio_data data = { 0 }; + + return __iomap_dio_rw(iocb, iter, &btrfs_dio_iomap_ops, &btrfs_dio_ops, + IOMAP_DIO_PARTIAL, &data, done_before); +} + +static ssize_t check_direct_IO(struct btrfs_fs_info *fs_info, + const struct iov_iter *iter, loff_t offset) +{ + const u32 blocksize_mask = fs_info->sectorsize - 1; + + if (offset & blocksize_mask) + return -EINVAL; + + if (iov_iter_alignment(iter) & blocksize_mask) + return -EINVAL; + + return 0; +} + +ssize_t btrfs_direct_write(struct kiocb *iocb, struct iov_iter *from) +{ + struct file *file = iocb->ki_filp; + struct inode *inode = file_inode(file); + struct btrfs_fs_info *fs_info = inode_to_fs_info(inode); + loff_t pos; + ssize_t written = 0; + ssize_t written_buffered; + size_t prev_left = 0; + loff_t endbyte; + ssize_t ret; + unsigned int ilock_flags = 0; + struct iomap_dio *dio; + + if (iocb->ki_flags & IOCB_NOWAIT) + ilock_flags |= BTRFS_ILOCK_TRY; + + /* + * If the write DIO is within EOF, use a shared lock and also only if + * security bits will likely not be dropped by file_remove_privs() called + * from btrfs_write_check(). Either will need to be rechecked after the + * lock was acquired. + */ + if (iocb->ki_pos + iov_iter_count(from) <= i_size_read(inode) && IS_NOSEC(inode)) + ilock_flags |= BTRFS_ILOCK_SHARED; + +relock: + ret = btrfs_inode_lock(BTRFS_I(inode), ilock_flags); + if (ret < 0) + return ret; + + /* Shared lock cannot be used with security bits set. */ + if ((ilock_flags & BTRFS_ILOCK_SHARED) && !IS_NOSEC(inode)) { + btrfs_inode_unlock(BTRFS_I(inode), ilock_flags); + ilock_flags &= ~BTRFS_ILOCK_SHARED; + goto relock; + } + + ret = generic_write_checks(iocb, from); + if (ret <= 0) { + btrfs_inode_unlock(BTRFS_I(inode), ilock_flags); + return ret; + } + + ret = btrfs_write_check(iocb, from, ret); + if (ret < 0) { + btrfs_inode_unlock(BTRFS_I(inode), ilock_flags); + goto out; + } + + pos = iocb->ki_pos; + /* + * Re-check since file size may have changed just before taking the + * lock or pos may have changed because of O_APPEND in generic_write_check() + */ + if ((ilock_flags & BTRFS_ILOCK_SHARED) && + pos + iov_iter_count(from) > i_size_read(inode)) { + btrfs_inode_unlock(BTRFS_I(inode), ilock_flags); + ilock_flags &= ~BTRFS_ILOCK_SHARED; + goto relock; + } + + if (check_direct_IO(fs_info, from, pos)) { + btrfs_inode_unlock(BTRFS_I(inode), ilock_flags); + goto buffered; + } + + /* + * The iov_iter can be mapped to the same file range we are writing to. + * If that's the case, then we will deadlock in the iomap code, because + * it first calls our callback btrfs_dio_iomap_begin(), which will create + * an ordered extent, and after that it will fault in the pages that the + * iov_iter refers to. During the fault in we end up in the readahead + * pages code (starting at btrfs_readahead()), which will lock the range, + * find that ordered extent and then wait for it to complete (at + * btrfs_lock_and_flush_ordered_range()), resulting in a deadlock since + * obviously the ordered extent can never complete as we didn't submit + * yet the respective bio(s). This always happens when the buffer is + * memory mapped to the same file range, since the iomap DIO code always + * invalidates pages in the target file range (after starting and waiting + * for any writeback). + * + * So here we disable page faults in the iov_iter and then retry if we + * got -EFAULT, faulting in the pages before the retry. + */ + from->nofault = true; + dio = btrfs_dio_write(iocb, from, written); + from->nofault = false; + + /* + * iomap_dio_complete() will call btrfs_sync_file() if we have a dsync + * iocb, and that needs to lock the inode. So unlock it before calling + * iomap_dio_complete() to avoid a deadlock. + */ + btrfs_inode_unlock(BTRFS_I(inode), ilock_flags); + + if (IS_ERR_OR_NULL(dio)) + ret = PTR_ERR_OR_ZERO(dio); + else + ret = iomap_dio_complete(dio); + + /* No increment (+=) because iomap returns a cumulative value. */ + if (ret > 0) + written = ret; + + if (iov_iter_count(from) > 0 && (ret == -EFAULT || ret > 0)) { + const size_t left = iov_iter_count(from); + /* + * We have more data left to write. Try to fault in as many as + * possible of the remainder pages and retry. We do this without + * releasing and locking again the inode, to prevent races with + * truncate. + * + * Also, in case the iov refers to pages in the file range of the + * file we want to write to (due to a mmap), we could enter an + * infinite loop if we retry after faulting the pages in, since + * iomap will invalidate any pages in the range early on, before + * it tries to fault in the pages of the iov. So we keep track of + * how much was left of iov in the previous EFAULT and fallback + * to buffered IO in case we haven't made any progress. + */ + if (left == prev_left) { + ret = -ENOTBLK; + } else { + fault_in_iov_iter_readable(from, left); + prev_left = left; + goto relock; + } + } + + /* + * If 'ret' is -ENOTBLK or we have not written all data, then it means + * we must fallback to buffered IO. + */ + if ((ret < 0 && ret != -ENOTBLK) || !iov_iter_count(from)) + goto out; + +buffered: + /* + * If we are in a NOWAIT context, then return -EAGAIN to signal the caller + * it must retry the operation in a context where blocking is acceptable, + * because even if we end up not blocking during the buffered IO attempt + * below, we will block when flushing and waiting for the IO. + */ + if (iocb->ki_flags & IOCB_NOWAIT) { + ret = -EAGAIN; + goto out; + } + + pos = iocb->ki_pos; + written_buffered = btrfs_buffered_write(iocb, from); + if (written_buffered < 0) { + ret = written_buffered; + goto out; + } + /* + * Ensure all data is persisted. We want the next direct IO read to be + * able to read what was just written. + */ + endbyte = pos + written_buffered - 1; + ret = btrfs_fdatawrite_range(BTRFS_I(inode), pos, endbyte); + if (ret) + goto out; + ret = filemap_fdatawait_range(inode->i_mapping, pos, endbyte); + if (ret) + goto out; + written += written_buffered; + iocb->ki_pos = pos + written_buffered; + invalidate_mapping_pages(file->f_mapping, pos >> PAGE_SHIFT, + endbyte >> PAGE_SHIFT); +out: + return ret < 0 ? ret : written; +} + +static int check_direct_read(struct btrfs_fs_info *fs_info, + const struct iov_iter *iter, loff_t offset) +{ + int ret; + int i, seg; + + ret = check_direct_IO(fs_info, iter, offset); + if (ret < 0) + return ret; + + if (!iter_is_iovec(iter)) + return 0; + + for (seg = 0; seg < iter->nr_segs; seg++) { + for (i = seg + 1; i < iter->nr_segs; i++) { + const struct iovec *iov1 = iter_iov(iter) + seg; + const struct iovec *iov2 = iter_iov(iter) + i; + + if (iov1->iov_base == iov2->iov_base) + return -EINVAL; + } + } + return 0; +} + +ssize_t btrfs_direct_read(struct kiocb *iocb, struct iov_iter *to) +{ + struct inode *inode = file_inode(iocb->ki_filp); + size_t prev_left = 0; + ssize_t read = 0; + ssize_t ret; + + if (fsverity_active(inode)) + return 0; + + if (check_direct_read(inode_to_fs_info(inode), to, iocb->ki_pos)) + return 0; + + btrfs_inode_lock(BTRFS_I(inode), BTRFS_ILOCK_SHARED); +again: + /* + * This is similar to what we do for direct IO writes, see the comment + * at btrfs_direct_write(), but we also disable page faults in addition + * to disabling them only at the iov_iter level. This is because when + * reading from a hole or prealloc extent, iomap calls iov_iter_zero(), + * which can still trigger page fault ins despite having set ->nofault + * to true of our 'to' iov_iter. + * + * The difference to direct IO writes is that we deadlock when trying + * to lock the extent range in the inode's tree during he page reads + * triggered by the fault in (while for writes it is due to waiting for + * our own ordered extent). This is because for direct IO reads, + * btrfs_dio_iomap_begin() returns with the extent range locked, which + * is only unlocked in the endio callback (end_bio_extent_readpage()). + */ + pagefault_disable(); + to->nofault = true; + ret = btrfs_dio_read(iocb, to, read); + to->nofault = false; + pagefault_enable(); + + /* No increment (+=) because iomap returns a cumulative value. */ + if (ret > 0) + read = ret; + + if (iov_iter_count(to) > 0 && (ret == -EFAULT || ret > 0)) { + const size_t left = iov_iter_count(to); + + if (left == prev_left) { + /* + * We didn't make any progress since the last attempt, + * fallback to a buffered read for the remainder of the + * range. This is just to avoid any possibility of looping + * for too long. + */ + ret = read; + } else { + /* + * We made some progress since the last retry or this is + * the first time we are retrying. Fault in as many pages + * as possible and retry. + */ + fault_in_iov_iter_writeable(to, left); + prev_left = left; + goto again; + } + } + btrfs_inode_unlock(BTRFS_I(inode), BTRFS_ILOCK_SHARED); + return ret < 0 ? ret : read; +} + +int __init btrfs_init_dio(void) +{ + if (bioset_init(&btrfs_dio_bioset, BIO_POOL_SIZE, + offsetof(struct btrfs_dio_private, bbio.bio), + BIOSET_NEED_BVECS)) + return -ENOMEM; + + return 0; +} + +void __cold btrfs_destroy_dio(void) +{ + bioset_exit(&btrfs_dio_bioset); +} diff --git a/fs/btrfs/direct-io.h b/fs/btrfs/direct-io.h new file mode 100644 index 000000000000..3dc3ea926afe --- /dev/null +++ b/fs/btrfs/direct-io.h @@ -0,0 +1,14 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef BTRFS_DIRECT_IO_H +#define BTRFS_DIRECT_IO_H + +#include <linux/types.h> + +int __init btrfs_init_dio(void); +void __cold btrfs_destroy_dio(void); + +ssize_t btrfs_direct_write(struct kiocb *iocb, struct iov_iter *from); +ssize_t btrfs_direct_read(struct kiocb *iocb, struct iov_iter *to); + +#endif /* BTRFS_DIRECT_IO_H */ diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 5834d452677f..21381de906f6 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -17,8 +17,8 @@ #include <linux/uio.h> #include <linux/iversion.h> #include <linux/fsverity.h> -#include <linux/iomap.h> #include "ctree.h" +#include "direct-io.h" #include "disk-io.h" #include "transaction.h" #include "btrfs_inode.h" @@ -1140,8 +1140,7 @@ static void update_time_for_write(struct inode *inode) inode_inc_iversion(inode); } -static int btrfs_write_check(struct kiocb *iocb, struct iov_iter *from, - size_t count) +int btrfs_write_check(struct kiocb *iocb, struct iov_iter *from, size_t count) { struct file *file = iocb->ki_filp; struct inode *inode = file_inode(file); @@ -1187,8 +1186,7 @@ static int btrfs_write_check(struct kiocb *iocb, struct iov_iter *from, return 0; } -static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb, - struct iov_iter *i) +ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) { struct file *file = iocb->ki_filp; loff_t pos; @@ -1451,194 +1449,6 @@ out: return num_written ? num_written : ret; } -static ssize_t check_direct_IO(struct btrfs_fs_info *fs_info, - const struct iov_iter *iter, loff_t offset) -{ - const u32 blocksize_mask = fs_info->sectorsize - 1; - - if (offset & blocksize_mask) - return -EINVAL; - - if (iov_iter_alignment(iter) & blocksize_mask) - return -EINVAL; - - return 0; -} - -static ssize_t btrfs_direct_write(struct kiocb *iocb, struct iov_iter *from) -{ - struct file *file = iocb->ki_filp; - struct inode *inode = file_inode(file); - struct btrfs_fs_info *fs_info = inode_to_fs_info(inode); - loff_t pos; - ssize_t written = 0; - ssize_t written_buffered; - size_t prev_left = 0; - loff_t endbyte; - ssize_t ret; - unsigned int ilock_flags = 0; - struct iomap_dio *dio; - - if (iocb->ki_flags & IOCB_NOWAIT) - ilock_flags |= BTRFS_ILOCK_TRY; - - /* - * If the write DIO is within EOF, use a shared lock and also only if - * security bits will likely not be dropped by file_remove_privs() called - * from btrfs_write_check(). Either will need to be rechecked after the - * lock was acquired. - */ - if (iocb->ki_pos + iov_iter_count(from) <= i_size_read(inode) && IS_NOSEC(inode)) - ilock_flags |= BTRFS_ILOCK_SHARED; - -relock: - ret = btrfs_inode_lock(BTRFS_I(inode), ilock_flags); - if (ret < 0) - return ret; - - /* Shared lock cannot be used with security bits set. */ - if ((ilock_flags & BTRFS_ILOCK_SHARED) && !IS_NOSEC(inode)) { - btrfs_inode_unlock(BTRFS_I(inode), ilock_flags); - ilock_flags &= ~BTRFS_ILOCK_SHARED; - goto relock; - } - - ret = generic_write_checks(iocb, from); - if (ret <= 0) { - btrfs_inode_unlock(BTRFS_I(inode), ilock_flags); - return ret; - } - - ret = btrfs_write_check(iocb, from, ret); - if (ret < 0) { - btrfs_inode_unlock(BTRFS_I(inode), ilock_flags); - goto out; - } - - pos = iocb->ki_pos; - /* - * Re-check since file size may have changed just before taking the - * lock or pos may have changed because of O_APPEND in generic_write_check() - */ - if ((ilock_flags & BTRFS_ILOCK_SHARED) && - pos + iov_iter_count(from) > i_size_read(inode)) { - btrfs_inode_unlock(BTRFS_I(inode), ilock_flags); - ilock_flags &= ~BTRFS_ILOCK_SHARED; - goto relock; - } - - if (check_direct_IO(fs_info, from, pos)) { - btrfs_inode_unlock(BTRFS_I(inode), ilock_flags); - goto buffered; - } - - /* - * The iov_iter can be mapped to the same file range we are writing to. - * If that's the case, then we will deadlock in the iomap code, because - * it first calls our callback btrfs_dio_iomap_begin(), which will create - * an ordered extent, and after that it will fault in the pages that the - * iov_iter refers to. During the fault in we end up in the readahead - * pages code (starting at btrfs_readahead()), which will lock the range, - * find that ordered extent and then wait for it to complete (at - * btrfs_lock_and_flush_ordered_range()), resulting in a deadlock since - * obviously the ordered extent can never complete as we didn't submit - * yet the respective bio(s). This always happens when the buffer is - * memory mapped to the same file range, since the iomap DIO code always - * invalidates pages in the target file range (after starting and waiting - * for any writeback). - * - * So here we disable page faults in the iov_iter and then retry if we - * got -EFAULT, faulting in the pages before the retry. - */ - from->nofault = true; - dio = btrfs_dio_write(iocb, from, written); - from->nofault = false; - - /* - * iomap_dio_complete() will call btrfs_sync_file() if we have a dsync - * iocb, and that needs to lock the inode. So unlock it before calling - * iomap_dio_complete() to avoid a deadlock. - */ - btrfs_inode_unlock(BTRFS_I(inode), ilock_flags); - - if (IS_ERR_OR_NULL(dio)) - ret = PTR_ERR_OR_ZERO(dio); - else - ret = iomap_dio_complete(dio); - - /* No increment (+=) because iomap returns a cumulative value. */ - if (ret > 0) - written = ret; - - if (iov_iter_count(from) > 0 && (ret == -EFAULT || ret > 0)) { - const size_t left = iov_iter_count(from); - /* - * We have more data left to write. Try to fault in as many as - * possible of the remainder pages and retry. We do this without - * releasing and locking again the inode, to prevent races with - * truncate. - * - * Also, in case the iov refers to pages in the file range of the - * file we want to write to (due to a mmap), we could enter an - * infinite loop if we retry after faulting the pages in, since - * iomap will invalidate any pages in the range early on, before - * it tries to fault in the pages of the iov. So we keep track of - * how much was left of iov in the previous EFAULT and fallback - * to buffered IO in case we haven't made any progress. - */ - if (left == prev_left) { - ret = -ENOTBLK; - } else { - fault_in_iov_iter_readable(from, left); - prev_left = left; - goto relock; - } - } - - /* - * If 'ret' is -ENOTBLK or we have not written all data, then it means - * we must fallback to buffered IO. - */ - if ((ret < 0 && ret != -ENOTBLK) || !iov_iter_count(from)) - goto out; - -buffered: - /* - * If we are in a NOWAIT context, then return -EAGAIN to signal the caller - * it must retry the operation in a context where blocking is acceptable, - * because even if we end up not blocking during the buffered IO attempt - * below, we will block when flushing and waiting for the IO. - */ - if (iocb->ki_flags & IOCB_NOWAIT) { - ret = -EAGAIN; - goto out; - } - - pos = iocb->ki_pos; - written_buffered = btrfs_buffered_write(iocb, from); - if (written_buffered < 0) { - ret = written_buffered; - goto out; - } - /* - * Ensure all data is persisted. We want the next direct IO read to be - * able to read what was just written. - */ - endbyte = pos + written_buffered - 1; - ret = btrfs_fdatawrite_range(BTRFS_I(inode), pos, endbyte); - if (ret) - goto out; - ret = filemap_fdatawait_range(inode->i_mapping, pos, endbyte); - if (ret) - goto out; - written += written_buffered; - iocb->ki_pos = pos + written_buffered; - invalidate_mapping_pages(file->f_mapping, pos >> PAGE_SHIFT, - endbyte >> PAGE_SHIFT); -out: - return ret < 0 ? ret : written; -} - static ssize_t btrfs_encoded_write(struct kiocb *iocb, struct iov_iter *from, const struct btrfs_ioctl_encoded_io_args *encoded) { @@ -3914,97 +3724,6 @@ static int btrfs_file_open(struct inode *inode, struct file *filp) return generic_file_open(inode, filp); } -static int check_direct_read(struct btrfs_fs_info *fs_info, - const struct iov_iter *iter, loff_t offset) -{ - int ret; - int i, seg; - - ret = check_direct_IO(fs_info, iter, offset); - if (ret < 0) - return ret; - - if (!iter_is_iovec(iter)) - return 0; - - for (seg = 0; seg < iter->nr_segs; seg++) { - for (i = seg + 1; i < iter->nr_segs; i++) { - const struct iovec *iov1 = iter_iov(iter) + seg; - const struct iovec *iov2 = iter_iov(iter) + i; - - if (iov1->iov_base == iov2->iov_base) - return -EINVAL; - } - } - return 0; -} - -static ssize_t btrfs_direct_read(struct kiocb *iocb, struct iov_iter *to) -{ - struct inode *inode = file_inode(iocb->ki_filp); - size_t prev_left = 0; - ssize_t read = 0; - ssize_t ret; - - if (fsverity_active(inode)) - return 0; - - if (check_direct_read(inode_to_fs_info(inode), to, iocb->ki_pos)) - return 0; - - btrfs_inode_lock(BTRFS_I(inode), BTRFS_ILOCK_SHARED); -again: - /* - * This is similar to what we do for direct IO writes, see the comment - * at btrfs_direct_write(), but we also disable page faults in addition - * to disabling them only at the iov_iter level. This is because when - * reading from a hole or prealloc extent, iomap calls iov_iter_zero(), - * which can still trigger page fault ins despite having set ->nofault - * to true of our 'to' iov_iter. - * - * The difference to direct IO writes is that we deadlock when trying - * to lock the extent range in the inode's tree during he page reads - * triggered by the fault in (while for writes it is due to waiting for - * our own ordered extent). This is because for direct IO reads, - * btrfs_dio_iomap_begin() returns with the extent range locked, which - * is only unlocked in the endio callback (end_bio_extent_readpage()). - */ - pagefault_disable(); - to->nofault = true; - ret = btrfs_dio_read(iocb, to, read); - to->nofault = false; - pagefault_enable(); - - /* No increment (+=) because iomap returns a cumulative value. */ - if (ret > 0) - read = ret; - - if (iov_iter_count(to) > 0 && (ret == -EFAULT || ret > 0)) { - const size_t left = iov_iter_count(to); - - if (left == prev_left) { - /* - * We didn't make any progress since the last attempt, - * fallback to a buffered read for the remainder of the - * range. This is just to avoid any possibility of looping - * for too long. - */ - ret = read; - } else { - /* - * We made some progress since the last retry or this is - * the first time we are retrying. Fault in as many pages - * as possible and retry. - */ - fault_in_iov_iter_writeable(to, left); - prev_left = left; - goto again; - } - } - btrfs_inode_unlock(BTRFS_I(inode), BTRFS_ILOCK_SHARED); - return ret < 0 ? ret : read; -} - static ssize_t btrfs_file_read_iter(struct kiocb *iocb, struct iov_iter *to) { ssize_t ret = 0; diff --git a/fs/btrfs/file.h b/fs/btrfs/file.h index ce93ed7083ab..912254e653cf 100644 --- a/fs/btrfs/file.h +++ b/fs/btrfs/file.h @@ -44,5 +44,7 @@ void btrfs_check_nocow_unlock(struct btrfs_inode *inode); bool btrfs_find_delalloc_in_range(struct btrfs_inode *inode, u64 start, u64 end, struct extent_state **cached_state, u64 *delalloc_start_ret, u64 *delalloc_end_ret); +int btrfs_write_check(struct kiocb *iocb, struct iov_iter *from, size_t count); +ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i); #endif diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 87ab9db69976..90f26b0464b8 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -77,25 +77,6 @@ struct btrfs_iget_args { struct btrfs_root *root; }; -struct btrfs_dio_data { - ssize_t submitted; - struct extent_changeset *data_reserved; - struct btrfs_ordered_extent *ordered; - bool data_space_reserved; - bool nocow_done; -}; - -struct btrfs_dio_private { - /* Range of I/O */ - u64 file_offset; - u32 bytes; - - /* This must be last */ - struct btrfs_bio bbio; -}; - -static struct bio_set btrfs_dio_bioset; - struct btrfs_rename_ctx { /* Output field. Stores the index number of the old directory entry. */ u64 index; @@ -138,9 +119,6 @@ static noinline int run_delalloc_cow(struct btrfs_inode *inode, struct page *locked_page, u64 start, u64 end, struct writeback_control *wbc, bool pages_dirty); -static struct extent_map *create_io_em(struct btrfs_inode *inode, u64 start, - const struct btrfs_file_extent *file_extent, - int type); static int data_reloc_print_warning_inode(u64 inum, u64 offset, u64 num_bytes, u64 root, void *warn_ctx) @@ -1205,7 +1183,7 @@ static void submit_one_async_extent(struct async_chunk *async_chunk, file_extent.offset = 0; file_extent.compression = async_extent->compress_type; - em = create_io_em(inode, start, &file_extent, BTRFS_ORDERED_COMPRESSED); + em = btrfs_create_io_em(inode, start, &file_extent, BTRFS_ORDERED_COMPRESSED); if (IS_ERR(em)) { ret = PTR_ERR(em); goto out_free_reserve; @@ -1257,8 +1235,8 @@ out_free_reserve: kfree(async_extent); } -static u64 get_extent_allocation_hint(struct btrfs_inode *inode, u64 start, - u64 num_bytes) +u64 btrfs_get_extent_allocation_hint(struct btrfs_inode *inode, u64 start, + u64 num_bytes) { struct extent_map_tree *em_tree = &inode->extent_tree; struct extent_map *em; @@ -1368,7 +1346,7 @@ static noinline int cow_file_range(struct btrfs_inode *inode, } } - alloc_hint = get_extent_allocation_hint(inode, start, num_bytes); + alloc_hint = btrfs_get_extent_allocation_hint(inode, start, num_bytes); /* * Relocation relies on the relocated extents to have exactly the same @@ -1435,7 +1413,8 @@ static noinline int cow_file_range(struct btrfs_inode *inode, lock_extent(&inode->io_tree, start, start + ram_size - 1, &cached); - em = create_io_em(inode, start, &file_extent, BTRFS_ORDERED_REGULAR); + em = btrfs_create_io_em(inode, start, &file_extent, + BTRFS_ORDERED_REGULAR); if (IS_ERR(em)) { unlock_extent(&inode->io_tree, start, start + ram_size - 1, &cached); @@ -2152,8 +2131,9 @@ must_cow: if (is_prealloc) { struct extent_map *em; - em = create_io_em(inode, cur_offset, &nocow_args.file_extent, - BTRFS_ORDERED_PREALLOC); + em = btrfs_create_io_em(inode, cur_offset, + &nocow_args.file_extent, + BTRFS_ORDERED_PREALLOC); if (IS_ERR(em)) { unlock_extent(&inode->io_tree, cur_offset, nocow_end, &cached_state); @@ -2582,44 +2562,6 @@ void btrfs_clear_delalloc_extent(struct btrfs_inode *inode, } } -static int btrfs_extract_ordered_extent(struct btrfs_bio *bbio, - struct btrfs_ordered_extent *ordered) -{ - u64 start = (u64)bbio->bio.bi_iter.bi_sector << SECTOR_SHIFT; - u64 len = bbio->bio.bi_iter.bi_size; - struct btrfs_ordered_extent *new; - int ret; - - /* Must always be called for the beginning of an ordered extent. */ - if (WARN_ON_ONCE(start != ordered->disk_bytenr)) - return -EINVAL; - - /* No need to split if the ordered extent covers the entire bio. */ - if (ordered->disk_num_bytes == len) { - refcount_inc(&ordered->refs); - bbio->ordered = ordered; - return 0; - } - - /* - * Don't split the extent_map for NOCOW extents, as we're writing into - * a pre-existing one. - */ - if (!test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags)) { - ret = split_extent_map(bbio->inode, bbio->file_offset, - ordered->num_bytes, len, - ordered->disk_bytenr); - if (ret) - return ret; - } - - new = btrfs_split_ordered_extent(ordered, len); - if (IS_ERR(new)) - return PTR_ERR(new); - bbio->ordered = new; - return 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. @@ -6995,81 +6937,6 @@ out: return em; } -static struct extent_map *btrfs_create_dio_extent(struct btrfs_inode *inode, - struct btrfs_dio_data *dio_data, - const u64 start, - const struct btrfs_file_extent *file_extent, - const int type) -{ - struct extent_map *em = NULL; - struct btrfs_ordered_extent *ordered; - - if (type != BTRFS_ORDERED_NOCOW) { - em = create_io_em(inode, start, file_extent, type); - if (IS_ERR(em)) - goto out; - } - - ordered = btrfs_alloc_ordered_extent(inode, start, file_extent, - (1 << type) | - (1 << BTRFS_ORDERED_DIRECT)); - if (IS_ERR(ordered)) { - if (em) { - free_extent_map(em); - btrfs_drop_extent_map_range(inode, start, - start + file_extent->num_bytes - 1, false); - } - em = ERR_CAST(ordered); - } else { - ASSERT(!dio_data->ordered); - dio_data->ordered = ordered; - } - out: - - return em; -} - -static struct extent_map *btrfs_new_extent_direct(struct btrfs_inode *inode, - struct btrfs_dio_data *dio_data, - u64 start, u64 len) -{ - struct btrfs_root *root = inode->root; - struct btrfs_fs_info *fs_info = root->fs_info; - struct btrfs_file_extent file_extent; - struct extent_map *em; - struct btrfs_key ins; - u64 alloc_hint; - int ret; - - alloc_hint = get_extent_allocation_hint(inode, start, len); -again: - ret = btrfs_reserve_extent(root, len, len, fs_info->sectorsize, - 0, alloc_hint, &ins, 1, 1); - if (ret == -EAGAIN) { - ASSERT(btrfs_is_zoned(fs_info)); - wait_on_bit_io(&inode->root->fs_info->flags, BTRFS_FS_NEED_ZONE_FINISH, - TASK_UNINTERRUPTIBLE); - goto again; - } - if (ret) - return ERR_PTR(ret); - - file_extent.disk_bytenr = ins.objectid; - file_extent.disk_num_bytes = ins.offset; - file_extent.num_bytes = ins.offset; - file_extent.ram_bytes = ins.offset; - file_extent.offset = 0; - file_extent.compression = BTRFS_COMPRESS_NONE; - em = btrfs_create_dio_extent(inode, dio_data, start, &file_extent, - BTRFS_ORDERED_REGULAR); - btrfs_dec_block_group_reservations(fs_info, ins.objectid); - if (IS_ERR(em)) - btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, - 1); - - return em; -} - static bool btrfs_extent_readonly(struct btrfs_fs_info *fs_info, u64 bytenr) { struct btrfs_block_group *block_group; @@ -7200,103 +7067,10 @@ out: return ret; } -static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend, - struct extent_state **cached_state, - unsigned int iomap_flags) -{ - const bool writing = (iomap_flags & IOMAP_WRITE); - const bool nowait = (iomap_flags & IOMAP_NOWAIT); - struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; - struct btrfs_ordered_extent *ordered; - int ret = 0; - - while (1) { - if (nowait) { - if (!try_lock_extent(io_tree, lockstart, lockend, - cached_state)) - return -EAGAIN; - } else { - lock_extent(io_tree, lockstart, lockend, cached_state); - } - /* - * We're concerned with the entire range that we're going to be - * doing DIO to, so we need to make sure there's no ordered - * extents in this range. - */ - ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), lockstart, - lockend - lockstart + 1); - - /* - * We need to make sure there are no buffered pages in this - * range either, we could have raced between the invalidate in - * generic_file_direct_write and locking the extent. The - * invalidate needs to happen so that reads after a write do not - * get stale data. - */ - if (!ordered && - (!writing || !filemap_range_has_page(inode->i_mapping, - lockstart, lockend))) - break; - - unlock_extent(io_tree, lockstart, lockend, cached_state); - - if (ordered) { - if (nowait) { - btrfs_put_ordered_extent(ordered); - ret = -EAGAIN; - break; - } - /* - * If we are doing a DIO read and the ordered extent we - * found is for a buffered write, we can not wait for it - * to complete and retry, because if we do so we can - * deadlock with concurrent buffered writes on page - * locks. This happens only if our DIO read covers more - * than one extent map, if at this point has already - * created an ordered extent for a previous extent map - * and locked its range in the inode's io tree, and a - * concurrent write against that previous extent map's - * range and this range started (we unlock the ranges - * in the io tree only when the bios complete and - * buffered writes always lock pages before attempting - * to lock range in the io tree). - */ - if (writing || - test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags)) - btrfs_start_ordered_extent(ordered); - else - ret = nowait ? -EAGAIN : -ENOTBLK; - btrfs_put_ordered_extent(ordered); - } else { - /* - * We could trigger writeback for this range (and wait - * for it to complete) and then invalidate the pages for - * this range (through invalidate_inode_pages2_range()), - * but that can lead us to a deadlock with a concurrent - * call to readahead (a buffered read or a defrag call - * triggered a readahead) on a page lock due to an - * ordered dio extent we created before but did not have - * yet a corresponding bio submitted (whence it can not - * complete), which makes readahead wait for that - * ordered extent to complete while holding a lock on - * that page. - */ - ret = nowait ? -EAGAIN : -ENOTBLK; - } - - if (ret) - break; - - cond_resched(); - } - - return ret; -} - /* The callers of this must take lock_extent() */ -static struct extent_map *create_io_em(struct btrfs_inode *inode, u64 start, - const struct btrfs_file_extent *file_extent, - int type) +struct extent_map *btrfs_create_io_em(struct btrfs_inode *inode, u64 start, + const struct btrfs_file_extent *file_extent, + int type) { struct extent_map *em; int ret; @@ -7363,527 +7137,6 @@ static struct extent_map *create_io_em(struct btrfs_inode *inode, u64 start, return em; } - -static int btrfs_get_blocks_direct_write(struct extent_map **map, - struct inode *inode, - struct btrfs_dio_data *dio_data, - u64 start, u64 *lenp, - unsigned int iomap_flags) -{ - const bool nowait = (iomap_flags & IOMAP_NOWAIT); - struct btrfs_fs_info *fs_info = inode_to_fs_info(inode); - struct btrfs_file_extent file_extent; - struct extent_map *em = *map; - int type; - u64 block_start; - struct btrfs_block_group *bg; - bool can_nocow = false; - bool space_reserved = false; - u64 len = *lenp; - u64 prev_len; - int ret = 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 ((em->flags & EXTENT_FLAG_PREALLOC) || - ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) && - em->disk_bytenr != EXTENT_MAP_HOLE)) { - if (em->flags & EXTENT_FLAG_PREALLOC) - type = BTRFS_ORDERED_PREALLOC; - else - type = BTRFS_ORDERED_NOCOW; - len = min(len, em->len - (start - em->start)); - block_start = extent_map_block_start(em) + (start - em->start); - - if (can_nocow_extent(inode, start, &len, - &file_extent, false, false) == 1) { - bg = btrfs_inc_nocow_writers(fs_info, block_start); - if (bg) - can_nocow = true; - } - } - - prev_len = len; - if (can_nocow) { - struct extent_map *em2; - - /* We can NOCOW, so only need to reserve metadata space. */ - ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode), len, len, - nowait); - if (ret < 0) { - /* Our caller expects us to free the input extent map. */ - free_extent_map(em); - *map = NULL; - btrfs_dec_nocow_writers(bg); - if (nowait && (ret == -ENOSPC || ret == -EDQUOT)) - ret = -EAGAIN; - goto out; - } - space_reserved = true; - - em2 = btrfs_create_dio_extent(BTRFS_I(inode), dio_data, start, - &file_extent, type); - btrfs_dec_nocow_writers(bg); - if (type == BTRFS_ORDERED_PREALLOC) { - free_extent_map(em); - *map = em2; - em = em2; - } - - if (IS_ERR(em2)) { - ret = PTR_ERR(em2); - goto out; - } - - dio_data->nocow_done = true; - } else { - /* Our caller expects us to free the input extent map. */ - free_extent_map(em); - *map = NULL; - - if (nowait) { - ret = -EAGAIN; - goto out; - } - - /* - * If we could not allocate data space before locking the file - * range and we can't do a NOCOW write, then we have to fail. - */ - if (!dio_data->data_space_reserved) { - ret = -ENOSPC; - goto out; - } - - /* - * We have to COW and we have already reserved data space before, - * so now we reserve only metadata. - */ - ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode), len, len, - false); - if (ret < 0) - goto out; - space_reserved = true; - - em = btrfs_new_extent_direct(BTRFS_I(inode), dio_data, start, len); - if (IS_ERR(em)) { - ret = PTR_ERR(em); - goto out; - } - *map = em; - len = min(len, em->len - (start - em->start)); - if (len < prev_len) - btrfs_delalloc_release_metadata(BTRFS_I(inode), - prev_len - len, true); - } - - /* - * We have created our ordered extent, so we can now release our reservation - * for an outstanding extent. - */ - btrfs_delalloc_release_extents(BTRFS_I(inode), prev_len); - - /* - * Need to update the i_size under the extent lock so buffered - * readers will get the updated i_size when we unlock. - */ - if (start + len > i_size_read(inode)) - i_size_write(inode, start + len); -out: - if (ret && space_reserved) { - btrfs_delalloc_release_extents(BTRFS_I(inode), len); - btrfs_delalloc_release_metadata(BTRFS_I(inode), len, true); - } - *lenp = len; - return ret; -} - -static int btrfs_dio_iomap_begin(struct inode *inode, loff_t start, - loff_t length, unsigned int flags, struct iomap *iomap, - struct iomap *srcmap) -{ - struct iomap_iter *iter = container_of(iomap, struct iomap_iter, iomap); - struct btrfs_fs_info *fs_info = inode_to_fs_info(inode); - struct extent_map *em; - struct extent_state *cached_state = NULL; - struct btrfs_dio_data *dio_data = iter->private; - u64 lockstart, lockend; - const bool write = !!(flags & IOMAP_WRITE); - int ret = 0; - u64 len = length; - const u64 data_alloc_len = length; - bool unlock_extents = false; - - /* - * We could potentially fault if we have a buffer > PAGE_SIZE, and if - * we're NOWAIT we may submit a bio for a partial range and return - * EIOCBQUEUED, which would result in an errant short read. - * - * The best way to handle this would be to allow for partial completions - * of iocb's, so we could submit the partial bio, return and fault in - * the rest of the pages, and then submit the io for the rest of the - * range. However we don't have that currently, so simply return - * -EAGAIN at this point so that the normal path is used. - */ - if (!write && (flags & IOMAP_NOWAIT) && length > PAGE_SIZE) - return -EAGAIN; - - /* - * Cap the size of reads to that usually seen in buffered I/O as we need - * to allocate a contiguous array for the checksums. - */ - if (!write) - len = min_t(u64, len, fs_info->sectorsize * BTRFS_MAX_BIO_SECTORS); - - lockstart = start; - lockend = start + len - 1; - - /* - * iomap_dio_rw() only does filemap_write_and_wait_range(), which isn't - * enough if we've written compressed pages to this area, so we need to - * flush the dirty pages again to make absolutely sure that any - * outstanding dirty pages are on disk - the first flush only starts - * compression on the data, while keeping the pages locked, so by the - * time the second flush returns we know bios for the compressed pages - * were submitted and finished, and the pages no longer under writeback. - * - * If we have a NOWAIT request and we have any pages in the range that - * are locked, likely due to compression still in progress, we don't want - * to block on page locks. We also don't want to block on pages marked as - * dirty or under writeback (same as for the non-compression case). - * iomap_dio_rw() did the same check, but after that and before we got - * here, mmap'ed writes may have happened or buffered reads started - * (readpage() and readahead(), which lock pages), as we haven't locked - * the file range yet. - */ - if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, - &BTRFS_I(inode)->runtime_flags)) { - if (flags & IOMAP_NOWAIT) { - if (filemap_range_needs_writeback(inode->i_mapping, - lockstart, lockend)) - return -EAGAIN; - } else { - ret = filemap_fdatawrite_range(inode->i_mapping, start, - start + length - 1); - if (ret) - return ret; - } - } - - memset(dio_data, 0, sizeof(*dio_data)); - - /* - * We always try to allocate data space and must do it before locking - * the file range, to avoid deadlocks with concurrent writes to the same - * range if the range has several extents and the writes don't expand the - * current i_size (the inode lock is taken in shared mode). If we fail to - * allocate data space here we continue and later, after locking the - * file range, we fail with ENOSPC only if we figure out we can not do a - * NOCOW write. - */ - if (write && !(flags & IOMAP_NOWAIT)) { - ret = btrfs_check_data_free_space(BTRFS_I(inode), - &dio_data->data_reserved, - start, data_alloc_len, false); - if (!ret) - dio_data->data_space_reserved = true; - else if (ret && !(BTRFS_I(inode)->flags & - (BTRFS_INODE_NODATACOW | BTRFS_INODE_PREALLOC))) - goto err; - } - - /* - * If this errors out it's because we couldn't invalidate pagecache for - * this range and we need to fallback to buffered IO, or we are doing a - * NOWAIT read/write and we need to block. - */ - ret = lock_extent_direct(inode, lockstart, lockend, &cached_state, flags); - if (ret < 0) - goto err; - - em = btrfs_get_extent(BTRFS_I(inode), NULL, start, len); - if (IS_ERR(em)) { - ret = PTR_ERR(em); - goto unlock_err; - } - - /* - * 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 that's 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 (extent_map_is_compressed(em) || em->disk_bytenr == EXTENT_MAP_INLINE) { - free_extent_map(em); - /* - * If we are in a NOWAIT context, return -EAGAIN in order to - * fallback to buffered IO. This is not only because we can - * block with buffered IO (no support for NOWAIT semantics at - * the moment) but also to avoid returning short reads to user - * space - this happens if we were able to read some data from - * previous non-compressed extents and then when we fallback to - * buffered IO, at btrfs_file_read_iter() by calling - * filemap_read(), we fail to fault in pages for the read buffer, - * in which case filemap_read() returns a short read (the number - * of bytes previously read is > 0, so it does not return -EFAULT). - */ - ret = (flags & IOMAP_NOWAIT) ? -EAGAIN : -ENOTBLK; - goto unlock_err; - } - - len = min(len, em->len - (start - em->start)); - - /* - * If we have a NOWAIT request and the range contains multiple extents - * (or a mix of extents and holes), then we return -EAGAIN to make the - * caller fallback to a context where it can do a blocking (without - * NOWAIT) request. This way we avoid doing partial IO and returning - * success to the caller, which is not optimal for writes and for reads - * it can result in unexpected behaviour for an application. - * - * When doing a read, because we use IOMAP_DIO_PARTIAL when calling - * iomap_dio_rw(), we can end up returning less data then what the caller - * asked for, resulting in an unexpected, and incorrect, short read. - * That is, the caller asked to read N bytes and we return less than that, - * which is wrong unless we are crossing EOF. This happens if we get a - * page fault error when trying to fault in pages for the buffer that is - * associated to the struct iov_iter passed to iomap_dio_rw(), and we - * have previously submitted bios for other extents in the range, in - * which case iomap_dio_rw() may return us EIOCBQUEUED if not all of - * those bios have completed by the time we get the page fault error, - * which we return back to our caller - we should only return EIOCBQUEUED - * after we have submitted bios for all the extents in the range. - */ - if ((flags & IOMAP_NOWAIT) && len < length) { - free_extent_map(em); - ret = -EAGAIN; - goto unlock_err; - } - - if (write) { - ret = btrfs_get_blocks_direct_write(&em, inode, dio_data, - start, &len, flags); - if (ret < 0) - goto unlock_err; - unlock_extents = true; - /* Recalc len in case the new em is smaller than requested */ - len = min(len, em->len - (start - em->start)); - if (dio_data->data_space_reserved) { - u64 release_offset; - u64 release_len = 0; - - if (dio_data->nocow_done) { - release_offset = start; - release_len = data_alloc_len; - } else if (len < data_alloc_len) { - release_offset = start + len; - release_len = data_alloc_len - len; - } - - if (release_len > 0) - btrfs_free_reserved_data_space(BTRFS_I(inode), - dio_data->data_reserved, - release_offset, - release_len); - } - } else { - /* - * We need to unlock only the end area that we aren't using. - * The rest is going to be unlocked by the endio routine. - */ - lockstart = start + len; - if (lockstart < lockend) - unlock_extents = true; - } - - if (unlock_extents) - unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend, - &cached_state); - else - free_extent_state(cached_state); - - /* - * Translate extent map information to iomap. - * We trim the extents (and move the addr) even though iomap code does - * that, since we have locked only the parts we are performing I/O in. - */ - if ((em->disk_bytenr == EXTENT_MAP_HOLE) || - ((em->flags & EXTENT_FLAG_PREALLOC) && !write)) { - iomap->addr = IOMAP_NULL_ADDR; - iomap->type = IOMAP_HOLE; - } else { - iomap->addr = extent_map_block_start(em) + (start - em->start); - iomap->type = IOMAP_MAPPED; - } - iomap->offset = start; - iomap->bdev = fs_info->fs_devices->latest_dev->bdev; - iomap->length = len; - free_extent_map(em); - - return 0; - -unlock_err: - unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend, - &cached_state); -err: - if (dio_data->data_space_reserved) { - btrfs_free_reserved_data_space(BTRFS_I(inode), - dio_data->data_reserved, - start, data_alloc_len); - extent_changeset_free(dio_data->data_reserved); - } - - return ret; -} - -static int btrfs_dio_iomap_end(struct inode *inode, loff_t pos, loff_t length, - ssize_t written, unsigned int flags, struct iomap *iomap) -{ - struct iomap_iter *iter = container_of(iomap, struct iomap_iter, iomap); - struct btrfs_dio_data *dio_data = iter->private; - size_t submitted = dio_data->submitted; - const bool write = !!(flags & IOMAP_WRITE); - int ret = 0; - - if (!write && (iomap->type == IOMAP_HOLE)) { - /* If reading from a hole, unlock and return */ - unlock_extent(&BTRFS_I(inode)->io_tree, pos, pos + length - 1, - NULL); - return 0; - } - - if (submitted < length) { - pos += submitted; - length -= submitted; - if (write) - btrfs_finish_ordered_extent(dio_data->ordered, NULL, - pos, length, false); - else - unlock_extent(&BTRFS_I(inode)->io_tree, pos, - pos + length - 1, NULL); - ret = -ENOTBLK; - } - if (write) { - btrfs_put_ordered_extent(dio_data->ordered); - dio_data->ordered = NULL; - } - - if (write) - extent_changeset_free(dio_data->data_reserved); - return ret; -} - -static void btrfs_dio_end_io(struct btrfs_bio *bbio) -{ - struct btrfs_dio_private *dip = - container_of(bbio, struct btrfs_dio_private, bbio); - struct btrfs_inode *inode = bbio->inode; - struct bio *bio = &bbio->bio; - - if (bio->bi_status) { - btrfs_warn(inode->root->fs_info, - "direct IO failed ino %llu op 0x%0x offset %#llx len %u err no %d", - btrfs_ino(inode), bio->bi_opf, - dip->file_offset, dip->bytes, bio->bi_status); - } - - if (btrfs_op(bio) == BTRFS_MAP_WRITE) { - btrfs_finish_ordered_extent(bbio->ordered, NULL, - dip->file_offset, dip->bytes, - !bio->bi_status); - } else { - unlock_extent(&inode->io_tree, dip->file_offset, - dip->file_offset + dip->bytes - 1, NULL); - } - - bbio->bio.bi_private = bbio->private; - iomap_dio_bio_end_io(bio); -} - -static void btrfs_dio_submit_io(const struct iomap_iter *iter, struct bio *bio, - loff_t file_offset) -{ - struct btrfs_bio *bbio = btrfs_bio(bio); - struct btrfs_dio_private *dip = - container_of(bbio, struct btrfs_dio_private, bbio); - struct btrfs_dio_data *dio_data = iter->private; - - btrfs_bio_init(bbio, BTRFS_I(iter->inode)->root->fs_info, - btrfs_dio_end_io, bio->bi_private); - bbio->inode = BTRFS_I(iter->inode); - bbio->file_offset = file_offset; - - dip->file_offset = file_offset; - dip->bytes = bio->bi_iter.bi_size; - - dio_data->submitted += bio->bi_iter.bi_size; - - /* - * Check if we are doing a partial write. If we are, we need to split - * the ordered extent to match the submitted bio. Hang on to the - * remaining unfinishable ordered_extent in dio_data so that it can be - * cancelled in iomap_end to avoid a deadlock wherein faulting the - * remaining pages is blocked on the outstanding ordered extent. - */ - if (iter->flags & IOMAP_WRITE) { - int ret; - - ret = btrfs_extract_ordered_extent(bbio, dio_data->ordered); - if (ret) { - btrfs_finish_ordered_extent(dio_data->ordered, NULL, - file_offset, dip->bytes, - !ret); - bio->bi_status = errno_to_blk_status(ret); - iomap_dio_bio_end_io(bio); - return; - } - } - - btrfs_submit_bio(bbio, 0); -} - -static const struct iomap_ops btrfs_dio_iomap_ops = { - .iomap_begin = btrfs_dio_iomap_begin, - .iomap_end = btrfs_dio_iomap_end, -}; - -static const struct iomap_dio_ops btrfs_dio_ops = { - .submit_io = btrfs_dio_submit_io, - .bio_set = &btrfs_dio_bioset, -}; - -ssize_t btrfs_dio_read(struct kiocb *iocb, struct iov_iter *iter, size_t done_before) -{ - struct btrfs_dio_data data = { 0 }; - - return iomap_dio_rw(iocb, iter, &btrfs_dio_iomap_ops, &btrfs_dio_ops, - IOMAP_DIO_PARTIAL, &data, done_before); -} - -struct iomap_dio *btrfs_dio_write(struct kiocb *iocb, struct iov_iter *iter, - size_t done_before) -{ - struct btrfs_dio_data data = { 0 }; - - return __iomap_dio_rw(iocb, iter, &btrfs_dio_iomap_ops, &btrfs_dio_ops, - IOMAP_DIO_PARTIAL, &data, done_before); -} - /* * For release_folio() and invalidate_folio() we have a race window where * folio_end_writeback() is called but the subpage spinlock is not yet released. @@ -8503,7 +7756,6 @@ void __cold btrfs_destroy_cachep(void) * destroy cache. */ rcu_barrier(); - bioset_exit(&btrfs_dio_bioset); kmem_cache_destroy(btrfs_inode_cachep); } @@ -8514,17 +7766,9 @@ int __init btrfs_init_cachep(void) SLAB_RECLAIM_ACCOUNT | SLAB_ACCOUNT, init_once); if (!btrfs_inode_cachep) - goto fail; - - if (bioset_init(&btrfs_dio_bioset, BIO_POOL_SIZE, - offsetof(struct btrfs_dio_private, bbio.bio), - BIOSET_NEED_BVECS)) - goto fail; + return -ENOMEM; return 0; -fail: - btrfs_destroy_cachep(); - return -ENOMEM; } static int btrfs_getattr(struct mnt_idmap *idmap, @@ -10267,7 +9511,7 @@ ssize_t btrfs_do_encoded_write(struct kiocb *iocb, struct iov_iter *from, file_extent.ram_bytes = ram_bytes; file_extent.offset = encoded->unencoded_offset; file_extent.compression = compression; - em = create_io_em(inode, start, &file_extent, BTRFS_ORDERED_COMPRESSED); + em = btrfs_create_io_em(inode, start, &file_extent, BTRFS_ORDERED_COMPRESSED); if (IS_ERR(em)) { ret = PTR_ERR(em); goto out_free_reserved; diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 715686e8d4cb..5450a01cb69c 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -34,6 +34,7 @@ #include "disk-io.h" #include "transaction.h" #include "btrfs_inode.h" +#include "direct-io.h" #include "props.h" #include "xattr.h" #include "bio.h" @@ -2490,6 +2491,9 @@ static const struct init_sequence mod_init_seq[] = { .init_func = btrfs_init_cachep, .exit_func = btrfs_destroy_cachep, }, { + .init_func = btrfs_init_dio, + .exit_func = btrfs_destroy_dio, + }, { .init_func = btrfs_transaction_init, .exit_func = btrfs_transaction_exit, }, { |