From fe8bc91c4c30122b357d197117705cfd4fabaf28 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Fri, 16 Oct 2009 19:26:15 +0200 Subject: ext3: Wait for proper transaction commit on fsync We cannot rely on buffer dirty bits during fsync because pdflush can come before fsync is called and clear dirty bits without forcing a transaction commit. What we do is that we track which transaction has last changed the inode and which transaction last changed allocation and force it to disk on fsync. Signed-off-by: Jan Kara Reviewed-by: Aneesh Kumar K.V --- fs/ext3/fsync.c | 36 ++++++++++++++++-------------------- 1 file changed, 16 insertions(+), 20 deletions(-) (limited to 'fs/ext3/fsync.c') diff --git a/fs/ext3/fsync.c b/fs/ext3/fsync.c index 451d166bbe93..8209f266e9ad 100644 --- a/fs/ext3/fsync.c +++ b/fs/ext3/fsync.c @@ -46,19 +46,21 @@ int ext3_sync_file(struct file * file, struct dentry *dentry, int datasync) { struct inode *inode = dentry->d_inode; + struct ext3_inode_info *ei = EXT3_I(inode); + journal_t *journal = EXT3_SB(inode->i_sb)->s_journal; int ret = 0; + tid_t commit_tid; + + if (inode->i_sb->s_flags & MS_RDONLY) + return 0; J_ASSERT(ext3_journal_current_handle() == NULL); /* - * data=writeback: + * data=writeback,ordered: * The caller's filemap_fdatawrite()/wait will sync the data. - * sync_inode() will sync the metadata - * - * data=ordered: - * The caller's filemap_fdatawrite() will write the data and - * sync_inode() will write the inode if it is dirty. Then the caller's - * filemap_fdatawait() will wait on the pages. + * Metadata is in the journal, we wait for a proper transaction + * to commit here. * * data=journal: * filemap_fdatawrite won't do anything (the buffers are clean). @@ -73,22 +75,16 @@ int ext3_sync_file(struct file * file, struct dentry *dentry, int datasync) goto out; } - if (datasync && !(inode->i_state & I_DIRTY_DATASYNC)) - goto flush; + if (datasync) + commit_tid = atomic_read(&ei->i_datasync_tid); + else + commit_tid = atomic_read(&ei->i_sync_tid); - /* - * The VFS has written the file data. If the inode is unaltered - * then we need not start a commit. - */ - if (inode->i_state & (I_DIRTY_SYNC|I_DIRTY_DATASYNC)) { - struct writeback_control wbc = { - .sync_mode = WB_SYNC_ALL, - .nr_to_write = 0, /* sys_fsync did this */ - }; - ret = sync_inode(inode, &wbc); + if (log_start_commit(journal, commit_tid)) { + log_wait_commit(journal, commit_tid); goto out; } -flush: + /* * In case we didn't commit a transaction, we have to flush * disk caches manually so that data really is on persistent -- cgit v1.2.3