ext4, jbd2: add REQ_FUA flag when recording an error in the superblock

When an error condition is detected, an error status should be recorded into
superblocks of EXT4 or JBD2. However, the write request is submitted now
without REQ_FUA flag, even in "barrier=1" mode, which is followed by
panic() function in "errors=panic" mode. On mobile devices which make
whole system reset as soon as kernel panic occurs, this write request
containing an error flag will disappear just from storage cache without
written to the physical cells. Therefore, when next start, even forever,
the error flag cannot be shown in both superblocks, and e2fsck cannot fix
the filesystem problems automatically, unless e2fsck is executed in
force checking mode.

[ Changed use test_opt(sb, BARRIER) of checking the journal flags -- TYT ]

Signed-off-by: Daeho Jeong <daeho.jeong@samsung.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 14909cd91515d207d0b22f79cad193a186b719bc..a51db9ca90fd5ec3fe06a260ac00c57bd0323ba7 100644 (file)
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -4667,7 +4667,8 @@ static int ext4_commit_super(struct super_block *sb, int sync)
        ext4_superblock_csum_set(sb);
        mark_buffer_dirty(sbh);
        if (sync) {
-               error = sync_dirty_buffer(sbh);
+               error = __sync_dirty_buffer(sbh,
+                       test_opt(sb, BARRIER) ? WRITE_FUA : WRITE_SYNC);
                if (error)
                        return error;
 

diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 4ff3fad4e9e3f53ba62ded94045f2062337017c0..fe1b4bdecdfa5f5e4aadfbfbd1493db5896ecf4b 100644 (file)
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -1456,7 +1456,7 @@ void jbd2_journal_update_sb_errno(journal_t *journal)
        sb->s_errno    = cpu_to_be32(journal->j_errno);
        read_unlock(&journal->j_state_lock);
 
-       jbd2_write_superblock(journal, WRITE_SYNC);
+       jbd2_write_superblock(journal, WRITE_FUA);
 }
 EXPORT_SYMBOL(jbd2_journal_update_sb_errno);