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| author | Mikulas Patocka <mpatocka@redhat.com> | 2025-11-20 12:08:47 +0100 |
|---|---|---|
| committer | Mikulas Patocka <mpatocka@redhat.com> | 2025-11-20 19:50:42 +0100 |
| commit | a612d24e850b28c16384cf071636034935447e43 (patch) | |
| tree | 0dab8433a57d2bd217cd7a26757d14a56159fb12 | |
| parent | a6ee8422b4f2a591de010f4e60471060b13d4170 (diff) | |
dm: fix failure when empty flush's bi_sector points beyond the device end
An empty flush bio can have arbitrary bi_sector. The commit 2b1c6d7a890a
introduced a regression that device mapper would fail an empty flush bio
with -EIO if the sector pointed beyond the end of the device.
The commit introduced an optimization, that optimization would pass
flushes to __split_and_process_bio and __split_and_process_bio is not
prepared to handle empty bios. Fix this bug by passing only non-empty
flushes to __split_and_process_bio - non-empty flushes must have valid
bi_sector. Empty bios will go through __send_empty_flush, as they did
before the optimization.
This problem can be reproduced by running the lvm2 test:
make check_local T=lvconvert-thin.sh LVM_TEST_PREFER_BRD=0
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Fixes: 2b1c6d7a890a ("dm: optimize REQ_PREFLUSH with data when using the linear target")
Reported-by: Zdenek Kabelac <zkabelac@redhat.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
| -rw-r--r-- | drivers/md/dm.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c index f5e5e59b232b..6c83ab940af7 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -2005,7 +2005,7 @@ static void dm_split_and_process_bio(struct mapped_device *md, * linear target or multiple linear targets pointing to the same * device), we can send the flush with data directly to it. */ - if (map->flush_bypasses_map) { + if (bio->bi_iter.bi_size && map->flush_bypasses_map) { struct list_head *devices = dm_table_get_devices(map); if (devices->next == devices->prev) goto send_preflush_with_data; |