diff options
author | Mike Snitzer <snitzer@kernel.org> | 2023-10-26 02:29:03 +0300 |
---|---|---|
committer | Mike Snitzer <snitzer@kernel.org> | 2023-10-27 20:22:51 +0300 |
commit | 6f25dd1c57b8ba92d899eae4eda16573a2f78ffc (patch) | |
tree | 4b9b20253bdc2f3cec43857728f657b0813af255 /drivers | |
parent | 4a2fe2960891f1ccd7805d0973284fd44c2f12b4 (diff) | |
download | linux-6f25dd1c57b8ba92d899eae4eda16573a2f78ffc.tar.xz |
dm: respect REQ_NOWAIT flag in normal bios issued to DM
Update DM core's normal IO submission to allocate required memory
using GFP_NOWAIT if REQ_NOWAIT is set.
Tested with simple test provided in commit a9ce385344f916 ("dm: don't
attempt to queue IO under RCU protection") that was enhanced to check
error codes. Also tested using fio's pvsync2 with nowait=1.
But testing with induced GFP_NOWAIT allocation failures wasn't
performed (yet).
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/md/dm.c | 40 |
1 files changed, 29 insertions, 11 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c index b5b1b220dfd6..0dd8ddf40006 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -570,13 +570,15 @@ static void dm_end_io_acct(struct dm_io *io) dm_io_acct(io, true); } -static struct dm_io *alloc_io(struct mapped_device *md, struct bio *bio) +static struct dm_io *alloc_io(struct mapped_device *md, struct bio *bio, gfp_t gfp_mask) { struct dm_io *io; struct dm_target_io *tio; struct bio *clone; - clone = bio_alloc_clone(NULL, bio, GFP_NOIO, &md->mempools->io_bs); + clone = bio_alloc_clone(NULL, bio, gfp_mask, &md->mempools->io_bs); + if (unlikely(!clone)) + return NULL; tio = clone_to_tio(clone); tio->flags = 0; dm_tio_set_flag(tio, DM_TIO_INSIDE_DM_IO); @@ -1714,10 +1716,6 @@ static blk_status_t __split_and_process_bio(struct clone_info *ci) if (unlikely(!ti)) return BLK_STS_IOERR; - if (unlikely((ci->bio->bi_opf & REQ_NOWAIT) != 0) && - unlikely(!dm_target_supports_nowait(ti->type))) - return BLK_STS_NOTSUPP; - if (unlikely(ci->is_abnormal_io)) return __process_abnormal_io(ci, ti); @@ -1729,7 +1727,17 @@ static blk_status_t __split_and_process_bio(struct clone_info *ci) len = min_t(sector_t, max_io_len(ti, ci->sector), ci->sector_count); setup_split_accounting(ci, len); - clone = alloc_tio(ci, ti, 0, &len, GFP_NOIO); + + if (unlikely(ci->bio->bi_opf & REQ_NOWAIT)) { + if (unlikely(!dm_target_supports_nowait(ti->type))) + return BLK_STS_NOTSUPP; + + clone = alloc_tio(ci, ti, 0, &len, GFP_NOWAIT); + if (unlikely(!clone)) + return BLK_STS_AGAIN; + } else { + clone = alloc_tio(ci, ti, 0, &len, GFP_NOIO); + } __map_bio(clone); ci->sector += len; @@ -1738,11 +1746,11 @@ static blk_status_t __split_and_process_bio(struct clone_info *ci) return BLK_STS_OK; } -static void init_clone_info(struct clone_info *ci, struct mapped_device *md, +static void init_clone_info(struct clone_info *ci, struct dm_io *io, struct dm_table *map, struct bio *bio, bool is_abnormal) { ci->map = map; - ci->io = alloc_io(md, bio); + ci->io = io; ci->bio = bio; ci->is_abnormal_io = is_abnormal; ci->submit_as_polled = false; @@ -1777,8 +1785,18 @@ static void dm_split_and_process_bio(struct mapped_device *md, return; } - init_clone_info(&ci, md, map, bio, is_abnormal); - io = ci.io; + /* Only support nowait for normal IO */ + if (unlikely(bio->bi_opf & REQ_NOWAIT) && !is_abnormal) { + io = alloc_io(md, bio, GFP_NOWAIT); + if (unlikely(!io)) { + /* Unable to do anything without dm_io. */ + bio_wouldblock_error(bio); + return; + } + } else { + io = alloc_io(md, bio, GFP_NOIO); + } + init_clone_info(&ci, io, map, bio, is_abnormal); if (bio->bi_opf & REQ_PREFLUSH) { __send_empty_flush(&ci); |