/* * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. * Copyright (C) 2004-2007 Red Hat, Inc. All rights reserved. * * This copyrighted material is made available to anyone wishing to use, * modify, copy, or redistribute it subject to the terms and conditions * of the GNU General Public License version 2. */ #include #include #include #include #include #include #include #include #include #include #include #include #include "gfs2.h" #include "incore.h" #include "bmap.h" #include "glock.h" #include "inode.h" #include "log.h" #include "meta_io.h" #include "ops_address.h" #include "quota.h" #include "trans.h" #include "rgrp.h" #include "ops_file.h" #include "super.h" #include "util.h" #include "glops.h" static void gfs2_page_add_databufs(struct gfs2_inode *ip, struct page *page, unsigned int from, unsigned int to) { struct buffer_head *head = page_buffers(page); unsigned int bsize = head->b_size; struct buffer_head *bh; unsigned int start, end; for (bh = head, start = 0; bh != head || !start; bh = bh->b_this_page, start = end) { end = start + bsize; if (end <= from || start >= to) continue; if (gfs2_is_jdata(ip)) set_buffer_uptodate(bh); gfs2_trans_add_bh(ip->i_gl, bh, 0); } } /** * gfs2_get_block - Fills in a buffer head with details about a block * @inode: The inode * @lblock: The block number to look up * @bh_result: The buffer head to return the result in * @create: Non-zero if we may add block to the file * * Returns: errno */ int gfs2_get_block(struct inode *inode, sector_t lblock, struct buffer_head *bh_result, int create) { return gfs2_block_map(inode, lblock, create, bh_result); } /** * gfs2_get_block_noalloc - Fills in a buffer head with details about a block * @inode: The inode * @lblock: The block number to look up * @bh_result: The buffer head to return the result in * @create: Non-zero if we may add block to the file * * Returns: errno */ static int gfs2_get_block_noalloc(struct inode *inode, sector_t lblock, struct buffer_head *bh_result, int create) { int error; error = gfs2_block_map(inode, lblock, 0, bh_result); if (error) return error; if (bh_result->b_blocknr == 0) return -EIO; return 0; } static int gfs2_get_block_direct(struct inode *inode, sector_t lblock, struct buffer_head *bh_result, int create) { return gfs2_block_map(inode, lblock, 0, bh_result); } /** * gfs2_writepage - Write complete page * @page: Page to write * * Returns: errno * * Some of this is copied from block_write_full_page() although we still * call it to do most of the work. */ static int gfs2_writepage(struct page *page, struct writeback_control *wbc) { struct inode *inode = page->mapping->host; struct gfs2_inode *ip = GFS2_I(inode); struct gfs2_sbd *sdp = GFS2_SB(inode); loff_t i_size = i_size_read(inode); pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT; unsigned offset; int error; int done_trans = 0; if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl))) { unlock_page(page); return -EIO; } if (current->journal_info) goto out_ignore; /* Is the page fully outside i_size? (truncate in progress) */ offset = i_size & (PAGE_CACHE_SIZE-1); if (page->index > end_index || (page->index == end_index && !offset)) { page->mapping->a_ops->invalidatepage(page, 0); unlock_page(page); return 0; /* don't care */ } if ((sdp->sd_args.ar_data == GFS2_DATA_ORDERED || gfs2_is_jdata(ip)) && PageChecked(page)) { ClearPageChecked(page); error = gfs2_trans_begin(sdp, RES_DINODE + 1, 0); if (error) goto out_ignore; if (!page_has_buffers(page)) { create_empty_buffers(page, inode->i_sb->s_blocksize, (1 << BH_Dirty)|(1 << BH_Uptodate)); } gfs2_page_add_databufs(ip, page, 0, sdp->sd_vfs->s_blocksize-1); done_trans = 1; } error = block_write_full_page(page, gfs2_get_block_noalloc, wbc); if (done_trans) gfs2_trans_end(sdp); gfs2_meta_cache_flush(ip); return error; out_ignore: redirty_page_for_writepage(wbc, page); unlock_page(page); return 0; } /** * gfs2_writepages - Write a bunch of dirty pages back to disk * @mapping: The mapping to write * @wbc: Write-back control * * For journaled files and/or ordered writes this just falls back to the * kernel's default writepages path for now. We will probably want to change * that eventually (i.e. when we look at allocate on flush). * * For the data=writeback case though we can already ignore buffer heads * and write whole extents at once. This is a big reduction in the * number of I/O requests we send and the bmap calls we make in this case. */ static int gfs2_writepages(struct address_space *mapping, struct writeback_control *wbc) { struct inode *inode = mapping->host; struct gfs2_inode *ip = GFS2_I(inode); struct gfs2_sbd *sdp = GFS2_SB(inode); if (sdp->sd_args.ar_data == GFS2_DATA_WRITEBACK && !gfs2_is_jdata(ip)) return mpage_writepages(mapping, wbc, gfs2_get_block_noalloc); return generic_writepages(mapping, wbc); } /** * stuffed_readpage - Fill in a Linux page with stuffed file data * @ip: the inode * @page: the page * * Returns: errno */ static int stuffed_readpage(struct gfs2_inode *ip, struct page *page) { struct buffer_head *dibh; void *kaddr; int error; /* * Due to the order of unstuffing files and ->nopage(), we can be * asked for a zero page in the case of a stuffed file being extended, * so we need to supply one here. It doesn't happen often. */ if (unlikely(page->index)) { kaddr = kmap_atomic(page, KM_USER0); memset(kaddr, 0, PAGE_CACHE_SIZE); kunmap_atomic(kaddr, KM_USER0); flush_dcache_page(page); SetPageUptodate(page); return 0; } error = gfs2_meta_inode_buffer(ip, &dibh); if (error) return error; kaddr = kmap_atomic(page, KM_USER0); memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), ip->i_di.di_size); memset(kaddr + ip->i_di.di_size, 0, PAGE_CACHE_SIZE - ip->i_di.di_size); kunmap_atomic(kaddr, KM_USER0); flush_dcache_page(page); brelse(dibh); SetPageUptodate(page); return 0; } /** * gfs2_readpage - readpage with locking * @file: The file to read a page for. N.B. This may be NULL if we are * reading an internal file. * @page: The page to read * * Returns: errno */ static int gfs2_readpage(struct file *file, struct page *page) { struct gfs2_inode *ip = GFS2_I(page->mapping->host); struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host); struct gfs2_file *gf = NULL; struct gfs2_holder gh; int error; int do_unlock = 0; if (likely(file != &gfs2_internal_file_sentinel)) { if (file) { gf = file->private_data; if (test_bit(GFF_EXLOCK, &gf->f_flags)) /* gfs2_sharewrite_nopage has grabbed the ip->i_gl already */ goto skip_lock; } gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME|LM_FLAG_TRY_1CB, &gh); do_unlock = 1; error = gfs2_glock_nq_atime(&gh); if (unlikely(error)) goto out_unlock; } skip_lock: if (gfs2_is_stuffed(ip)) { error = stuffed_readpage(ip, page); unlock_page(page); } else error = mpage_readpage(page, gfs2_get_block); if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) error = -EIO; if (do_unlock) { gfs2_glock_dq_m(1, &gh); gfs2_holder_uninit(&gh); } out: return error; out_unlock: unlock_page(page); if (error == GLR_TRYFAILED) { error = AOP_TRUNCATED_PAGE; yield(); } if (do_unlock) gfs2_holder_uninit(&gh); goto out; } /** * gfs2_readpages - Read a bunch of pages at once * * Some notes: * 1. This is only for readahead, so we can simply ignore any things * which are slightly inconvenient (such as locking conflicts between * the page lock and the glock) and return having done no I/O. Its * obviously not something we'd want to do on too regular a basis. * Any I/O we ignore at this time will be done via readpage later. * 2. We don't handle stuffed files here we let readpage do the honours. * 3. mpage_readpages() does most of the heavy lifting in the common case. * 4. gfs2_get_block() is relied upon to set BH_Boundary in the right places. * 5. We use LM_FLAG_TRY_1CB here, effectively we then have lock-ahead as * well as read-ahead. */ static int gfs2_readpages(struct file *file, struct address_space *mapping, struct list_head *pages, unsigned nr_pages) { struct inode *inode = mapping->host; struct gfs2_inode *ip = GFS2_I(inode); struct gfs2_sbd *sdp = GFS2_SB(inode); struct gfs2_holder gh; int ret = 0; int do_unlock = 0; if (likely(file != &gfs2_internal_file_sentinel)) { if (file) { struct gfs2_file *gf = file->private_data; if (test_bit(GFF_EXLOCK, &gf->f_flags)) goto skip_lock; } gfs2_holder_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_TRY_1CB|GL_ATIME, &gh); do_unlock = 1; ret = gfs2_glock_nq_atime(&gh); if (ret == GLR_TRYFAILED) goto out_noerror; if (unlikely(ret)) goto out_unlock; } skip_lock: if (!gfs2_is_stuffed(ip)) ret = mpage_readpages(mapping, pages, nr_pages, gfs2_get_block); if (do_unlock) { gfs2_glock_dq_m(1, &gh); gfs2_holder_uninit(&gh); } out: if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) ret = -EIO; return ret; out_noerror: ret = 0; out_unlock: if (do_unlock) gfs2_holder_uninit(&gh); goto out; } /** * gfs2_prepare_write - Prepare to write a page to a file * @file: The file to write to * @page: The page which is to be prepared for writing * @from: From (byte range within page) * @to: To (byte range within page) * * Returns: errno */ static int gfs2_prepare_write(struct file *file, struct page *page, unsigned from, unsigned to) { struct gfs2_inode *ip = GFS2_I(page->mapping->host); struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host); unsigned int data_blocks, ind_blocks, rblocks; int alloc_required; int error = 0; loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + from; loff_t end = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to; struct gfs2_alloc *al; unsigned int write_len = to - from; gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_ATIME|LM_FLAG_TRY_1CB, &ip->i_gh); error = gfs2_glock_nq_atime(&ip->i_gh); if (unlikely(error)) { if (error == GLR_TRYFAILED) { unlock_page(page); error = AOP_TRUNCATED_PAGE; yield(); } goto out_uninit; } gfs2_write_calc_reserv(ip, write_len, &data_blocks, &ind_blocks); error = gfs2_write_alloc_required(ip, pos, write_len, &alloc_required); if (error) goto out_unlock; ip->i_alloc.al_requested = 0; if (alloc_required) { al = gfs2_alloc_get(ip); error = gfs2_quota_lock(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE); if (error) goto out_alloc_put; error = gfs2_quota_check(ip, ip->i_inode.i_uid, ip->i_inode.i_gid); if (error) goto out_qunlock; al->al_requested = data_blocks + ind_blocks; error = gfs2_inplace_reserve(ip); if (error) goto out_qunlock; } rblocks = RES_DINODE + ind_blocks; if (gfs2_is_jdata(ip)) rblocks += data_blocks ? data_blocks : 1; if (ind_blocks || data_blocks) rblocks += RES_STATFS + RES_QUOTA; error = gfs2_trans_begin(sdp, rblocks, 0); if (error) goto out; if (gfs2_is_stuffed(ip)) { if (end > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) { error = gfs2_unstuff_dinode(ip, page); if (error == 0) goto prepare_write; } else if (!PageUptodate(page)) error = stuffed_readpage(ip, page); goto out; } prepare_write: error = block_prepare_write(page, from, to, gfs2_get_block); out: if (error) { gfs2_trans_end(sdp); if (alloc_required) { gfs2_inplace_release(ip); out_qunlock: gfs2_quota_unlock(ip); out_alloc_put: gfs2_alloc_put(ip); } out_unlock: gfs2_glock_dq_m(1, &ip->i_gh); out_uninit: gfs2_holder_uninit(&ip->i_gh); } return error; } /** * adjust_fs_space - Adjusts the free space available due to gfs2_grow * @inode: the rindex inode */ static void adjust_fs_space(struct inode *inode) { struct gfs2_sbd *sdp = inode->i_sb->s_fs_info; struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master; struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local; u64 fs_total, new_free; /* Total up the file system space, according to the latest rindex. */ fs_total = gfs2_ri_total(sdp); spin_lock(&sdp->sd_statfs_spin); if (fs_total > (m_sc->sc_total + l_sc->sc_total)) new_free = fs_total - (m_sc->sc_total + l_sc->sc_total); else new_free = 0; spin_unlock(&sdp->sd_statfs_spin); fs_warn(sdp, "File system extended by %llu blocks.\n", (unsigned long long)new_free); gfs2_statfs_change(sdp, new_free, new_free, 0); } /** * gfs2_commit_write - Commit write to a file * @file: The file to write to * @page: The page containing the data * @from: From (byte range within page) * @to: To (byte range within page) * * Returns: errno */ static int gfs2_commit_write(struct file *file, struct page *page, unsigned from, unsigned to) { struct inode *inode = page->mapping->host; struct gfs2_inode *ip = GFS2_I(inode); struct gfs2_sbd *sdp = GFS2_SB(inode); int error = -EOPNOTSUPP; struct buffer_head *dibh; struct gfs2_alloc *al = &ip->i_alloc; struct gfs2_dinode *di; if (gfs2_assert_withdraw(sdp, gfs2_glock_is_locked_by_me(ip->i_gl))) goto fail_nounlock; error = gfs2_meta_inode_buffer(ip, &dibh); if (error) goto fail_endtrans; gfs2_trans_add_bh(ip->i_gl, dibh, 1); di = (struct gfs2_dinode *)dibh->b_data; if (gfs2_is_stuffed(ip)) { u64 file_size; void *kaddr; file_size = ((u64)page->index << PAGE_CACHE_SHIFT) + to; kaddr = kmap_atomic(page, KM_USER0); memcpy(dibh->b_data + sizeof(struct gfs2_dinode) + from, kaddr + from, to - from); kunmap_atomic(kaddr, KM_USER0); SetPageUptodate(page); if (inode->i_size < file_size) { i_size_write(inode, file_size); mark_inode_dirty(inode); } } else { if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED || gfs2_is_jdata(ip)) gfs2_page_add_databufs(ip, page, from, to); error = generic_commit_write(file, page, from, to); if (error) goto fail; } if (ip->i_di.di_size < inode->i_size) { ip->i_di.di_size = inode->i_size; di->di_size = cpu_to_be64(inode->i_size); } if (inode == sdp->sd_rindex) adjust_fs_space(inode); brelse(dibh); gfs2_trans_end(sdp); if (al->al_requested) { gfs2_inplace_release(ip); gfs2_quota_unlock(ip); gfs2_alloc_put(ip); } unlock_page(page); gfs2_glock_dq_m(1, &ip->i_gh); lock_page(page); gfs2_holder_uninit(&ip->i_gh); return 0; fail: brelse(dibh); fail_endtrans: gfs2_trans_end(sdp); if (al->al_requested) { gfs2_inplace_release(ip); gfs2_quota_unlock(ip); gfs2_alloc_put(ip); } unlock_page(page); gfs2_glock_dq_m(1, &ip->i_gh); lock_page(page); gfs2_holder_uninit(&ip->i_gh); fail_nounlock: ClearPageUptodate(page); return error; } /** * gfs2_set_page_dirty - Page dirtying function * @page: The page to dirty * * Returns: 1 if it dirtyed the page, or 0 otherwise */ static int gfs2_set_page_dirty(struct page *page) { struct gfs2_inode *ip = GFS2_I(page->mapping->host); struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host); if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED || gfs2_is_jdata(ip)) SetPageChecked(page); return __set_page_dirty_buffers(page); } /** * gfs2_bmap - Block map function * @mapping: Address space info * @lblock: The block to map * * Returns: The disk address for the block or 0 on hole or error */ static sector_t gfs2_bmap(struct address_space *mapping, sector_t lblock) { struct gfs2_inode *ip = GFS2_I(mapping->host); struct gfs2_holder i_gh; sector_t dblock = 0; int error; error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh); if (error) return 0; if (!gfs2_is_stuffed(ip)) dblock = generic_block_bmap(mapping, lblock, gfs2_get_block); gfs2_glock_dq_uninit(&i_gh); return dblock; } static void discard_buffer(struct gfs2_sbd *sdp, struct buffer_head *bh) { struct gfs2_bufdata *bd; gfs2_log_lock(sdp); bd = bh->b_private; if (bd) { bd->bd_bh = NULL; bh->b_private = NULL; if (!bd->bd_ail && list_empty(&bd->bd_le.le_list)) kmem_cache_free(gfs2_bufdata_cachep, bd); } gfs2_log_unlock(sdp); lock_buffer(bh); clear_buffer_dirty(bh); bh->b_bdev = NULL; clear_buffer_mapped(bh); clear_buffer_req(bh); clear_buffer_new(bh); clear_buffer_delay(bh); unlock_buffer(bh); } static void gfs2_invalidatepage(struct page *page, unsigned long offset) { struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host); struct buffer_head *head, *bh, *next; unsigned int curr_off = 0; BUG_ON(!PageLocked(page)); if (offset == 0) ClearPageChecked(page); if (!page_has_buffers(page)) return; bh = head = page_buffers(page); do { unsigned int next_off = curr_off + bh->b_size; next = bh->b_this_page; if (offset <= curr_off) discard_buffer(sdp, bh); curr_off = next_off; bh = next; } while (bh != head); if (!offset) try_to_release_page(page, 0); return; } /** * gfs2_ok_for_dio - check that dio is valid on this file * @ip: The inode * @rw: READ or WRITE * @offset: The offset at which we are reading or writing * * Returns: 0 (to ignore the i/o request and thus fall back to buffered i/o) * 1 (to accept the i/o request) */ static int gfs2_ok_for_dio(struct gfs2_inode *ip, int rw, loff_t offset) { /* * Should we return an error here? I can't see that O_DIRECT for * a journaled file makes any sense. For now we'll silently fall * back to buffered I/O, likewise we do the same for stuffed * files since they are (a) small and (b) unaligned. */ if (gfs2_is_jdata(ip)) return 0; if (gfs2_is_stuffed(ip)) return 0; if (offset > i_size_read(&ip->i_inode)) return 0; return 1; } static ssize_t gfs2_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 gfs2_inode *ip = GFS2_I(inode); struct gfs2_holder gh; int rv; /* * Deferred lock, even if its a write, since we do no allocation * on this path. All we need change is atime, and this lock mode * ensures that other nodes have flushed their buffered read caches * (i.e. their page cache entries for this inode). We do not, * unfortunately have the option of only flushing a range like * the VFS does. */ gfs2_holder_init(ip->i_gl, LM_ST_DEFERRED, GL_ATIME, &gh); rv = gfs2_glock_nq_atime(&gh); if (rv) return rv; rv = gfs2_ok_for_dio(ip, rw, offset); if (rv != 1) goto out; /* dio not valid, fall back to buffered i/o */ rv = blockdev_direct_IO_no_locking(rw, iocb, inode, inode->i_sb->s_bdev, iov, offset, nr_segs, gfs2_get_block_direct, NULL); out: gfs2_glock_dq_m(1, &gh); gfs2_holder_uninit(&gh); return rv; } /** * stuck_releasepage - We're stuck in gfs2_releasepage(). Print stuff out. * @bh: the buffer we're stuck on * */ static void stuck_releasepage(struct buffer_head *bh) { struct inode *inode = bh->b_page->mapping->host; struct gfs2_sbd *sdp = inode->i_sb->s_fs_info; struct gfs2_bufdata *bd = bh->b_private; struct gfs2_glock *gl; static unsigned limit = 0; if (limit > 3) return; limit++; fs_warn(sdp, "stuck in gfs2_releasepage() %p\n", inode); fs_warn(sdp, "blkno = %llu, bh->b_count = %d\n", (unsigned long long)bh->b_blocknr, atomic_read(&bh->b_count)); fs_warn(sdp, "pinned = %u\n", buffer_pinned(bh)); fs_warn(sdp, "bh->b_private = %s\n", (bd) ? "!NULL" : "NULL"); if (!bd) return; gl = bd->bd_gl; fs_warn(sdp, "gl = (%u, %llu)\n", gl->gl_name.ln_type, (unsigned long long)gl->gl_name.ln_number); fs_warn(sdp, "bd_list_tr = %s, bd_le.le_list = %s\n", (list_empty(&bd->bd_list_tr)) ? "no" : "yes", (list_empty(&bd->bd_le.le_list)) ? "no" : "yes"); if (gl->gl_ops == &gfs2_inode_glops) { struct gfs2_inode *ip = gl->gl_object; unsigned int x; if (!ip) return; fs_warn(sdp, "ip = %llu %llu\n", (unsigned long long)ip->i_no_formal_ino, (unsigned long long)ip->i_no_addr); for (x = 0; x < GFS2_MAX_META_HEIGHT; x++) fs_warn(sdp, "ip->i_cache[%u] = %s\n", x, (ip->i_cache[x]) ? "!NULL" : "NULL"); } } /** * gfs2_releasepage - free the metadata associated with a page * @page: the page that's being released * @gfp_mask: passed from Linux VFS, ignored by us * * Call try_to_free_buffers() if the buffers in this page can be * released. * * Returns: 0 */ int gfs2_releasepage(struct page *page, gfp_t gfp_mask) { struct inode *aspace = page->mapping->host; struct gfs2_sbd *sdp = aspace->i_sb->s_fs_info; struct buffer_head *bh, *head; struct gfs2_bufdata *bd; unsigned long t = jiffies + gfs2_tune_get(sdp, gt_stall_secs) * HZ; if (!page_has_buffers(page)) goto out; head = bh = page_buffers(page); do { while (atomic_read(&bh->b_count)) { if (!atomic_read(&aspace->i_writecount)) return 0; if (!(gfp_mask & __GFP_WAIT)) return 0; if (time_after_eq(jiffies, t)) { stuck_releasepage(bh); /* should we withdraw here? */ return 0; } yield(); } gfs2_assert_warn(sdp, !buffer_pinned(bh)); gfs2_assert_warn(sdp, !buffer_dirty(bh)); gfs2_log_lock(sdp); bd = bh->b_private; if (bd) { gfs2_assert_warn(sdp, bd->bd_bh == bh); gfs2_assert_warn(sdp, list_empty(&bd->bd_list_tr)); gfs2_assert_warn(sdp, !bd->bd_ail); bd->bd_bh = NULL; if (!list_empty(&bd->bd_le.le_list)) bd = NULL; bh->b_private = NULL; } gfs2_log_unlock(sdp); if (bd) kmem_cache_free(gfs2_bufdata_cachep, bd); bh = bh->b_this_page; } while (bh != head); out: return try_to_free_buffers(page); } const struct address_space_operations gfs2_file_aops = { .writepage = gfs2_writepage, .writepages = gfs2_writepages, .readpage = gfs2_readpage, .readpages = gfs2_readpages, .sync_page = block_sync_page, .prepare_write = gfs2_prepare_write, .commit_write = gfs2_commit_write, .set_page_dirty = gfs2_set_page_dirty, .bmap = gfs2_bmap, .invalidatepage = gfs2_invalidatepage, .releasepage = gfs2_releasepage, .direct_IO = gfs2_direct_IO, };