From b436b9bef84de6893e86346d8fbf7104bc520645 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Tue, 8 Dec 2009 23:51:10 -0500 Subject: ext4: 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 Signed-off-by: "Theodore Ts'o" --- fs/ext4/fsync.c | 46 +++++++++++++++++----------------------------- 1 file changed, 17 insertions(+), 29 deletions(-) (limited to 'fs/ext4/fsync.c') diff --git a/fs/ext4/fsync.c b/fs/ext4/fsync.c index a3c25076aef1..0b22497d92e1 100644 --- a/fs/ext4/fsync.c +++ b/fs/ext4/fsync.c @@ -51,25 +51,30 @@ int ext4_sync_file(struct file *file, struct dentry *dentry, int datasync) { struct inode *inode = dentry->d_inode; + struct ext4_inode_info *ei = EXT4_I(inode); journal_t *journal = EXT4_SB(inode->i_sb)->s_journal; - int err, ret = 0; + int ret; + tid_t commit_tid; J_ASSERT(ext4_journal_current_handle() == NULL); trace_ext4_sync_file(file, dentry, datasync); + if (inode->i_sb->s_flags & MS_RDONLY) + return 0; + ret = flush_aio_dio_completed_IO(inode); if (ret < 0) return ret; + + if (!journal) + return simple_fsync(file, dentry, datasync); + /* - * 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 proper transaction to + * commit here. * * data=journal: * filemap_fdatawrite won't do anything (the buffers are clean). @@ -82,27 +87,10 @@ int ext4_sync_file(struct file *file, struct dentry *dentry, int datasync) if (ext4_should_journal_data(inode)) return ext4_force_commit(inode->i_sb); - if (!journal) - ret = sync_mapping_buffers(inode->i_mapping); - - if (datasync && !(inode->i_state & I_DIRTY_DATASYNC)) - goto out; - - /* - * 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 */ - }; - err = sync_inode(inode, &wbc); - if (ret == 0) - ret = err; - } -out: - if (journal && (journal->j_flags & JBD2_BARRIER)) + commit_tid = datasync ? ei->i_datasync_tid : ei->i_sync_tid; + if (jbd2_log_start_commit(journal, commit_tid)) + jbd2_log_wait_commit(journal, commit_tid); + else if (journal->j_flags & JBD2_BARRIER) blkdev_issue_flush(inode->i_sb->s_bdev, NULL); return ret; } -- cgit v1.2.3