If filesystem was aborted we will return success due to (sb->s_flags & MS_RDONLY) which is incorrect and 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 - fix smp_rmb()/debug order Signed-off-by: Dmitry Monakhov <dmonakhov@xxxxxxxxxx> --- fs/ext3/fsync.c | 8 ++++++-- fs/ext3/super.c | 13 ++++++++++++- 2 files changed, 18 insertions(+), 3 deletions(-) diff --git a/fs/ext3/fsync.c b/fs/ext3/fsync.c index b31dbd4..5412916 100644 --- a/fs/ext3/fsync.c +++ b/fs/ext3/fsync.c @@ -48,9 +48,13 @@ int ext3_sync_file(struct file *file, loff_t start, loff_t end, int datasync) trace_ext3_sync_file_enter(file, datasync); - if (inode->i_sb->s_flags & MS_RDONLY) + if (inode->i_sb->s_flags & MS_RDONLY) { + /* Make shure that we read updated state */ + smp_rmb(); + if (EXT3_SB(inode->i_sb)->s_mount_state & EXT3_ERROR_FS) + return -EROFS; return 0; - + } ret = filemap_write_and_wait_range(inode->i_mapping, start, end); if (ret) goto out; diff --git a/fs/ext3/super.c b/fs/ext3/super.c index c8a4e17..b788bae 100644 --- a/fs/ext3/super.c +++ b/fs/ext3/super.c @@ -174,6 +174,11 @@ static void ext3_handle_error(struct super_block *sb) if (test_opt (sb, ERRORS_RO)) { ext3_msg(sb, KERN_CRIT, "error: remounting filesystem read-only"); + /* + * Make shure updated value of ->s_mount_state will be visiable + * before ->s_flags update. + */ + smp_wmb(); sb->s_flags |= MS_RDONLY; } ext3_commit_super(sb, es, 1); @@ -291,8 +296,14 @@ void ext3_abort(struct super_block *sb, const char *function, ext3_msg(sb, KERN_CRIT, "error: remounting filesystem read-only"); EXT3_SB(sb)->s_mount_state |= EXT3_ERROR_FS; - sb->s_flags |= MS_RDONLY; set_opt(EXT3_SB(sb)->s_mount_opt, ABORT); + /* + * Make shure updated value of ->s_mount_state will be visiable + * before ->s_flags update. + */ + smp_wmb(); + sb->s_flags |= MS_RDONLY; + if (EXT3_SB(sb)->s_journal) journal_abort(EXT3_SB(sb)->s_journal, -EIO); } -- 1.7.1 -- 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
