This is a note to let you know that I've just added the patch titled
dm cache metadata: fail operations if fail_io mode has been established
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
dm-cache-metadata-fail-operations-if-fail_io-mode-has-been-established.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 10add84e276432d9dd8044679a1028dd4084117e Mon Sep 17 00:00:00 2001
From: Mike Snitzer <snitzer@xxxxxxxxxx>
Date: Fri, 5 May 2017 14:40:13 -0400
Subject: dm cache metadata: fail operations if fail_io mode has been established
From: Mike Snitzer <snitzer@xxxxxxxxxx>
commit 10add84e276432d9dd8044679a1028dd4084117e upstream.
Otherwise it is possible to trigger crashes due to the metadata being
inaccessible yet these methods don't safely account for that possibility
without these checks.
Reported-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/md/dm-cache-metadata.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
--- a/drivers/md/dm-cache-metadata.c
+++ b/drivers/md/dm-cache-metadata.c
@@ -1383,17 +1383,19 @@ void dm_cache_metadata_set_stats(struct
int dm_cache_commit(struct dm_cache_metadata *cmd, bool clean_shutdown)
{
- int r;
+ int r = -EINVAL;
flags_mutator mutator = (clean_shutdown ? set_clean_shutdown :
clear_clean_shutdown);
WRITE_LOCK(cmd);
+ if (cmd->fail_io)
+ goto out;
+
r = __commit_transaction(cmd, mutator);
if (r)
goto out;
r = __begin_transaction(cmd);
-
out:
WRITE_UNLOCK(cmd);
return r;
@@ -1405,7 +1407,8 @@ int dm_cache_get_free_metadata_block_cou
int r = -EINVAL;
READ_LOCK(cmd);
- r = dm_sm_get_nr_free(cmd->metadata_sm, result);
+ if (!cmd->fail_io)
+ r = dm_sm_get_nr_free(cmd->metadata_sm, result);
READ_UNLOCK(cmd);
return r;
@@ -1417,7 +1420,8 @@ int dm_cache_get_metadata_dev_size(struc
int r = -EINVAL;
READ_LOCK(cmd);
- r = dm_sm_get_nr_blocks(cmd->metadata_sm, result);
+ if (!cmd->fail_io)
+ r = dm_sm_get_nr_blocks(cmd->metadata_sm, result);
READ_UNLOCK(cmd);
return r;
Patches currently in stable-queue which might be from snitzer@xxxxxxxxxx are
queue-4.9/dm-btree-fix-for-dm_btree_find_lowest_key.patch
queue-4.9/dm-bufio-avoid-a-possible-abba-deadlock.patch
queue-4.9/dm-cache-metadata-fail-operations-if-fail_io-mode-has-been-established.patch
queue-4.9/dm-raid-select-the-kconfig-option-config_md_raid0.patch
queue-4.9/dm-bufio-make-the-parameter-retain_bytes-unsigned-long.patch
queue-4.9/dm-space-map-disk-fix-some-book-keeping-in-the-disk-space-map.patch
queue-4.9/dm-mpath-split-and-rename-activate_path-to-prepare-for-its-expanded-use.patch
queue-4.9/dm-bufio-check-new-buffer-allocation-watermark-every-30-seconds.patch
queue-4.9/dm-thin-metadata-call-precommit-before-saving-the-roots.patch