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gfs2-utils: Wrong hash value used to clean journals

PATCH New Bob Peterson 2 participants 2 messages Dec 14, 2018 1 message not in the archive

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Bob Peterson

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PATCH 1/1 gfs2-utils: Wrong hash value used to clean journals

Hi,

When fsck.gfs2 sees a dirty journal, (one that does not have a log header with the UNMOUNT flag set at the wrap-point), it replays the journal and writes a log header out to "clean" the journal. Unfortunately, before this patch, it was using the wrong hash value. So every time fsck.gfs2 was run, it would not recognize its own log header because of the wrong hash, and therefore it would always see the journal as dirty with every run (until the file system is mounted and unmounted, which would write a new correct log header). Therefore, multiple runs of fsck.gfs2 would always result in a replay of the journal, which remains "dirty."

This patch changes function clean_journal so that it uses the correct hash function. Therefore, the journal will be truly clean and consecutive runs (or mounts) will find the journal clean.

Signed-off-by Bob Peterson <[email protected]>
---
 gfs2/libgfs2/recovery.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
gfs2/libgfs2/recovery.c +1 -1
index 6b14bf94..06f81116 100644
@@ -241,7 +241,7 @@ int clean_journal(struct gfs2_inode *ip, struct gfs2_log_header *head)
 	lh->lh_sequence = cpu_to_be64(head->lh_sequence + 1);
 	lh->lh_flags = cpu_to_be32(GFS2_LOG_HEAD_UNMOUNT);
 	lh->lh_blkno = cpu_to_be32(lblock);
-	hash = gfs2_disk_hash((const char *)lh, sizeof(struct gfs2_log_header));
+	hash = lgfs2_log_header_hash(bh->b_data);
 	lh->lh_hash = cpu_to_be32(hash);
 	bmodified(bh);
 	brelse(bh);
#2 lore raw

PATCH 1/1 gfs2-utils: Wrong hash value used to clean journals

Quoted 28 lines · Bob Peterson

Hi,

When fsck.gfs2 sees a dirty journal, (one that does not have a log header with the UNMOUNT flag set at the wrap-point), it replays the journal and writes a log header out to "clean" the journal. Unfortunately, before this patch, it was using the wrong hash value. So every time fsck.gfs2 was run, it would not recognize its own log header because of the wrong hash, and therefore it would always see the journal as dirty with every run (until the file system is mounted and unmounted, which would write a new correct log header). Therefore, multiple runs of fsck.gfs2 would always result in a replay of the journal, which remains "dirty."

This patch changes function clean_journal so that it uses the correct hash function. Therefore, the journal will be truly clean and consecutive runs (or mounts) will find the journal clean.

Signed-off-by Bob Peterson <[email protected]>
---
  gfs2/libgfs2/recovery.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)
gfs2/libgfs2/recovery.c +0 -0
index 6b14bf94..06f81116 100644

gfs2/libgfs2/recovery.c int clean_journal(struct gfs2_inode *ip, struct gfs2_log_header *head) · line 247

Quoted 8 lines
gfs2/libgfs2/recovery.c +1 -1
@@ -241,7 +241,7 @@ int clean_journal(struct gfs2_inode *ip, struct gfs2_log_header *head)
  	lh->lh_sequence = cpu_to_be64(head->lh_sequence + 1);
  	lh->lh_flags = cpu_to_be32(GFS2_LOG_HEAD_UNMOUNT);
  	lh->lh_blkno = cpu_to_be32(lblock);
-	hash = gfs2_disk_hash((const char *)lh, sizeof(struct gfs2_log_header));
+	hash = lgfs2_log_header_hash(bh->b_data);
  	lh->lh_hash = cpu_to_be32(hash);
  	bmodified(bh);
  	brelse(bh);

Thanks Bob, I've pushed the patch as it's a clear fix.

Andy