From: Theodore Ts'o <tytso@mit.edu>
Date: Sun, 5 Aug 2012 23:04:57 +0000 (-0400)
Subject: ext4: make sure the journal sb is written in ext4_clear_journal_err()
X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=d796c52ef0b71a988364f6109aeb63d79c5b116b;p=openwrt%2Fstaging%2Fblogic.git

ext4: make sure the journal sb is written in ext4_clear_journal_err()

After we transfer set the EXT4_ERROR_FS bit in the file system
superblock, it's not enough to call jbd2_journal_clear_err() to clear
the error indication from journal superblock --- we need to call
jbd2_journal_update_sb_errno() as well.  Otherwise, when the root file
system is mounted read-only, the journal is replayed, and the error
indicator is transferred to the superblock --- but the s_errno field
in the jbd2 superblock is left set (since although we cleared it in
memory, we never flushed it out to disk).

This can end up confusing e2fsck.  We should make e2fsck more robust
in this case, but the kernel shouldn't be leaving things in this
confused state, either.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
---

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index d76ec8277d3f..ccc4bcad5616 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -4430,6 +4430,7 @@ static void ext4_clear_journal_err(struct super_block *sb,
 		ext4_commit_super(sb, 1);
 
 		jbd2_journal_clear_err(journal);
+		jbd2_journal_update_sb_errno(journal);
 	}
 }
 
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index e9a3c4c85594..bd23f2ebaa67 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -1377,7 +1377,7 @@ static void jbd2_mark_journal_empty(journal_t *journal)
  * Update a journal's errno.  Write updated superblock to disk waiting for IO
  * to complete.
  */
-static void jbd2_journal_update_sb_errno(journal_t *journal)
+void jbd2_journal_update_sb_errno(journal_t *journal)
 {
 	journal_superblock_t *sb = journal->j_superblock;
 
@@ -1390,6 +1390,7 @@ static void jbd2_journal_update_sb_errno(journal_t *journal)
 
 	jbd2_write_superblock(journal, WRITE_SYNC);
 }
+EXPORT_SYMBOL(jbd2_journal_update_sb_errno);
 
 /*
  * Read the superblock for a given journal, performing initial
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index f334c7fab967..3efc43f3f162 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -1125,6 +1125,7 @@ extern int	   jbd2_journal_destroy    (journal_t *);
 extern int	   jbd2_journal_recover    (journal_t *journal);
 extern int	   jbd2_journal_wipe       (journal_t *, int);
 extern int	   jbd2_journal_skip_recovery	(journal_t *);
+extern void	   jbd2_journal_update_sb_errno(journal_t *);
 extern void	   jbd2_journal_update_sb_log_tail	(journal_t *, tid_t,
 				unsigned long, int);
 extern void	   __jbd2_journal_abort_hard	(journal_t *);