ext4: fix synchronization of quota files in journal=data mode From: Jan Kara In journal=data mode, it is not enough to do write_inode_now as done in vfs_quota_on() to write all data to their final location (which is needed for quota_read to work correctly). Calling journal_flush() does its job. Cc: Signed-off-by: Jan Kara Signed-off-by: Andrew Morton Signed-off-by: Mingming Cao Signed-off-by: "Theodore Ts'o" --- fs/ext4/super.c | 35 +++++++++++++++++++++++++++-------- 1 file changed, 27 insertions(+), 8 deletions(-) Index: linux-2.6.26-rc1/fs/ext4/super.c =================================================================== --- linux-2.6.26-rc1.orig/fs/ext4/super.c 2008-05-05 17:10:11.000000000 -0700 +++ linux-2.6.26-rc1/fs/ext4/super.c 2008-05-05 17:10:12.000000000 -0700 @@ -3170,23 +3170,42 @@ static int ext4_quota_on(struct super_bl if (!test_opt(sb, QUOTA)) return -EINVAL; - /* Not journalling quota? */ - if ((!EXT4_SB(sb)->s_qf_names[USRQUOTA] && - !EXT4_SB(sb)->s_qf_names[GRPQUOTA]) || remount) + /* When remounting, no checks are needed and in fact, path is NULL */ + if (remount) return vfs_quota_on(sb, type, format_id, path, remount); + err = path_lookup(path, LOOKUP_FOLLOW, &nd); if (err) return err; + /* Quotafile not on the same filesystem? */ if (nd.path.mnt->mnt_sb != sb) { path_put(&nd.path); return -EXDEV; } - /* Quotafile not of fs root? */ - if (nd.path.dentry->d_parent->d_inode != sb->s_root->d_inode) - printk(KERN_WARNING - "EXT4-fs: Quota file not on filesystem root. " - "Journalled quota will not work.\n"); + /* Journaling quota? */ + if (EXT4_SB(sb)->s_qf_names[type]) { + /* Quotafile not of fs root? */ + if (nd.path.dentry->d_parent->d_inode != sb->s_root->d_inode) + printk(KERN_WARNING + "EXT4-fs: Quota file not on filesystem root. " + "Journaled quota will not work.\n"); + } + + /* + * When we journal data on quota file, we have to flush journal to see + * all updates to the file when we bypass pagecache... + */ + if (ext4_should_journal_data(nd.path.dentry->d_inode)) { + /* + * We don't need to lock updates but journal_flush() could + * otherwise be livelocked... + */ + jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal); + jbd2_journal_flush(EXT4_SB(sb)->s_journal); + jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal); + } + path_put(&nd.path); return vfs_quota_on(sb, type, format_id, path, remount); }