|author||Mikulas Patocka <email@example.com>||2019-03-21 16:46:12 -0400|
|committer||Mike Snitzer <firstname.lastname@example.org>||2019-04-01 16:20:36 -0400|
dm: revert 8f50e358153d ("dm: limit the max bio size as BIO_MAX_PAGES * PAGE_SIZE")
The limit was already incorporated to dm-crypt with commit 4e870e948fba ("dm crypt: fix error with too large bios"), so we don't need to apply it globally to all targets. The quantity BIO_MAX_PAGES * PAGE_SIZE is wrong anyway because the variable ti->max_io_len it is supposed to be in the units of 512-byte sectors not in bytes. Reduction of the limit to 1048576 sectors could even cause data corruption in rare cases - suppose that we have a dm-striped device with stripe size 768MiB. The target will call dm_set_target_max_io_len with the value 1572864. The buggy code would reduce it to 1048576. Now, the dm-core will errorneously split the bios on 1048576-sector boundary insetad of 1572864-sector boundary and pass these stripe-crossing bios to the striped target. Cc: email@example.com # v4.16+ Fixes: 8f50e358153d ("dm: limit the max bio size as BIO_MAX_PAGES * PAGE_SIZE") Signed-off-by: Mikulas Patocka <firstname.lastname@example.org> Acked-by: Ming Lei <email@example.com> Signed-off-by: Mike Snitzer <firstname.lastname@example.org>
Diffstat (limited to 'drivers/md')
1 files changed, 1 insertions, 9 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 68d24056d0b1..89b04169658d 100644
@@ -1042,15 +1042,7 @@ int dm_set_target_max_io_len(struct dm_target *ti, sector_t len)
- * BIO based queue uses its own splitting. When multipage bvecs
- * is switched on, size of the incoming bio may be too big to
- * be handled in some targets, such as crypt.
- * When these targets are ready for the big bio, we can remove
- * the limit.
- ti->max_io_len = min_t(uint32_t, len, BIO_MAX_PAGES * PAGE_SIZE);
+ ti->max_io_len = (uint32_t) len;