[3.19.y-ckt stable] Patch "ext4: don't manipulate recovery flag when freezing no-journal fs" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    ext4: don't manipulate recovery flag when freezing no-journal fs

to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue

This patch is scheduled to be released in version 3.19.8-ckt8.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.19.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From e7eae1d1a8bb16b46f090673fe260673244e776b Mon Sep 17 00:00:00 2001
From: Eric Sandeen <sandeen at redhat.com>
Date: Sat, 15 Aug 2015 10:45:06 -0400
Subject: ext4: don't manipulate recovery flag when freezing no-journal fs

commit c642dc9e1aaed953597e7092d7df329e6234096e upstream.

At some point along this sequence of changes:

f6e63f9 ext4: fold ext4_nojournal_sops into ext4_sops
bb04457 ext4: support freezing ext2 (nojournal) file systems
9ca9238 ext4: Use separate super_operations structure for no_journal filesystems

ext4 started setting needs_recovery on filesystems without journals
when they are unfrozen.  This makes no sense, and in fact confuses
blkid to the point where it doesn't recognize the filesystem at all.

(freeze ext2; unfreeze ext2; run blkid; see no output; run dumpe2fs,
see needs_recovery set on fs w/ no journal).

To fix this, don't manipulate the INCOMPAT_RECOVER feature on
filesystems without journals.

Reported-by: Stu Mark <smark at datto.com>
Reviewed-by: Jan Kara <jack at suse.com>
Signed-off-by: Eric Sandeen <sandeen at redhat.com>
Signed-off-by: Theodore Ts'o <tytso at mit.edu>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 fs/ext4/super.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index e820414..47f678c 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -4761,10 +4761,11 @@ static int ext4_freeze(struct super_block *sb)
 		error = jbd2_journal_flush(journal);
 		if (error < 0)
 			goto out;
+
+		/* Journal blocked and flushed, clear needs_recovery flag. */
+		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 	}

-	/* Journal blocked and flushed, clear needs_recovery flag. */
-	EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 	error = ext4_commit_super(sb, 1);
 out:
 	if (journal)
@@ -4782,8 +4783,11 @@ static int ext4_unfreeze(struct super_block *sb)
 	if (sb->s_flags & MS_RDONLY)
 		return 0;

-	/* Reset the needs_recovery flag before the fs is unlocked. */
-	EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
+	if (EXT4_SB(sb)->s_journal) {
+		/* Reset the needs_recovery flag before the fs is unlocked. */
+		EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
+	}
+
 	ext4_commit_super(sb, 1);
 	return 0;
 }
--
1.9.1