On Tue 28-05-13 13:19:00, Dmitry Monakhov wrote: > If filesystem was aborted after inode's write back is complete > but before its metadata was updated we may return success > results in data loss. > In order to handle fs abort correctly we have to check > fs state once we discover that it is in MS_RDONLY state > > Test case: http://patchwork.ozlabs.org/patch/244297 > > Changes from V1: > - fix spelling Still not quite ;) Search for 'shure' and 'visiable'. But feel free to add Reviewed-by: Jan Kara <jack@xxxxxxx> Honza > > Signed-off-by: Dmitry Monakhov <dmonakhov@xxxxxxxxxx> > --- > fs/ext4/fsync.c | 8 ++++++-- > fs/ext4/super.c | 12 +++++++++++- > 2 files changed, 17 insertions(+), 3 deletions(-) > > diff --git a/fs/ext4/fsync.c b/fs/ext4/fsync.c > index e0ba8a4..d7df2f1 100644 > --- a/fs/ext4/fsync.c > +++ b/fs/ext4/fsync.c > @@ -129,9 +129,13 @@ int ext4_sync_file(struct file *file, loff_t start, loff_t end, int datasync) > return ret; > mutex_lock(&inode->i_mutex); > > - if (inode->i_sb->s_flags & MS_RDONLY) > + if (inode->i_sb->s_flags & MS_RDONLY) { > + /* Make shure that we read updated s_mount_flags value */ > + smp_rmb(); > + if (EXT4_SB(inode->i_sb)->s_mount_flags & EXT4_MF_FS_ABORTED) > + ret = -EROFS; > goto out; > - > + } > ret = ext4_flush_unwritten_io(inode); > if (ret < 0) > goto out; > diff --git a/fs/ext4/super.c b/fs/ext4/super.c > index edc716d..b4154d3 100644 > --- a/fs/ext4/super.c > +++ b/fs/ext4/super.c > @@ -399,6 +399,11 @@ static void ext4_handle_error(struct super_block *sb) > } > if (test_opt(sb, ERRORS_RO)) { > ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only"); > + /* > + * Make shure updated value of ->s_mount_flags will be visiable > + * before ->s_flags update > + */ > + smp_wmb(); > sb->s_flags |= MS_RDONLY; > } > if (test_opt(sb, ERRORS_PANIC)) > @@ -571,8 +576,13 @@ void __ext4_abort(struct super_block *sb, const char *function, > > if ((sb->s_flags & MS_RDONLY) == 0) { > ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only"); > - sb->s_flags |= MS_RDONLY; > EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED; > + /* > + * Make shure updated value of ->s_mount_flags will be visiable > + * before ->s_flags update > + */ > + smp_wmb(); > + sb->s_flags |= MS_RDONLY; > if (EXT4_SB(sb)->s_journal) > jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO); > save_error_info(sb, function, line); > -- > 1.7.1 > -- Jan Kara <jack@xxxxxxx> SUSE Labs, CR -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
