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authorDmitry Monakhov <dmonakhov@openvz.org>2013-05-28 13:19:01 +0400
committerJan Kara <jack@suse.cz>2013-07-04 19:22:55 +0200
commit3df32196519d1556b8851b610ca1aa68c5b673d3 (patch)
tree4d94cec2052684e7b2a27ca4769654aceca2ca9e
parenta1457c0ce976bad1356b9b0437f2a5c3ab8a9cfc (diff)
downloadop-kernel-dev-3df32196519d1556b8851b610ca1aa68c5b673d3.zip
op-kernel-dev-3df32196519d1556b8851b610ca1aa68c5b673d3.tar.gz
ext3: Fix fsync error handling after filesystem abort.
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@openvz.org> Signed-off-by: Jan Kara <jack@suse.cz>
-rw-r--r--fs/ext3/fsync.c8
-rw-r--r--fs/ext3/super.c13
2 files changed, 18 insertions, 3 deletions
diff --git a/fs/ext3/fsync.c b/fs/ext3/fsync.c
index b31dbd4..1cb9c7e 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 sure 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 6356665..c47f147 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 sure updated value of ->s_mount_state will be visible
+ * 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 sure updated value of ->s_mount_state will be visible
+ * 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);
}
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