diff options
| author | Christoph Hellwig <hch@lst.de> | 2015-05-22 09:14:04 -0400 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2015-05-22 08:58:57 -0600 |
| commit | 5f1b670d0bef508a5554d92525f5f6d00d640b38 (patch) | |
| tree | 18aaa4b5ead87568214b3d9c0f501d8a98c2a787 /drivers/md/dm.h | |
| parent | 326e1dbb57368087a36607aaebe9795b8d5453e5 (diff) | |
block, dm: don't copy bios for request clones
Currently dm-multipath has to clone the bios for every request sent
to the lower devices, which wastes cpu cycles and ties down memory.
This patch instead adds a new REQ_CLONE flag that instructs req_bio_endio
to not complete bios attached to a request, which we set on clone
requests similar to bios in a flush sequence. With this change I/O
errors on a path failure only get propagated to dm-multipath, which
can then either resubmit the I/O or complete the bios on the original
request.
I've done some basic testing of this on a Linux target with ALUA support,
and it survives path failures during I/O nicely.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'drivers/md/dm.h')
| -rw-r--r-- | drivers/md/dm.h | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/md/dm.h b/drivers/md/dm.h index 6123c2bf9150..e6e66d087b26 100644 --- a/drivers/md/dm.h +++ b/drivers/md/dm.h @@ -222,8 +222,9 @@ void dm_kcopyd_exit(void); /* * Mempool operations */ -struct dm_md_mempools *dm_alloc_md_mempools(struct mapped_device *md, unsigned type, - unsigned integrity, unsigned per_bio_data_size); +struct dm_md_mempools *dm_alloc_bio_mempools(unsigned integrity, + unsigned per_bio_data_size); +struct dm_md_mempools *dm_alloc_rq_mempools(struct mapped_device *md, unsigned type); void dm_free_md_mempools(struct dm_md_mempools *pools); /* |