diff options
author | Kent Overstreet <kent.overstreet@gmail.com> | 2015-04-24 05:37:18 (GMT) |
---|---|---|
committer | Jens Axboe <axboe@fb.com> | 2015-08-13 18:31:33 (GMT) |
commit | 54efd50bfd873e2dbf784e0b21a8027ba4299a3e (patch) | |
tree | 37bcd2d148b99b0f53f5a093eecd5cb3d8c9887c /drivers | |
parent | 41609892701e26724b8617201f43254cadf2e7ae (diff) | |
download | linux-54efd50bfd873e2dbf784e0b21a8027ba4299a3e.tar.xz |
block: make generic_make_request handle arbitrarily sized bios
The way the block layer is currently written, it goes to great lengths
to avoid having to split bios; upper layer code (such as bio_add_page())
checks what the underlying device can handle and tries to always create
bios that don't need to be split.
But this approach becomes unwieldy and eventually breaks down with
stacked devices and devices with dynamic limits, and it adds a lot of
complexity. If the block layer could split bios as needed, we could
eliminate a lot of complexity elsewhere - particularly in stacked
drivers. Code that creates bios can then create whatever size bios are
convenient, and more importantly stacked drivers don't have to deal with
both their own bio size limitations and the limitations of the
(potentially multiple) devices underneath them. In the future this will
let us delete merge_bvec_fn and a bunch of other code.
We do this by adding calls to blk_queue_split() to the various
make_request functions that need it - a few can already handle arbitrary
size bios. Note that we add the call _after_ any call to
blk_queue_bounce(); this means that blk_queue_split() and
blk_recalc_rq_segments() don't need to be concerned with bouncing
affecting segment merging.
Some make_request_fn() callbacks were simple enough to audit and verify
they don't need blk_queue_split() calls. The skipped ones are:
* nfhd_make_request (arch/m68k/emu/nfblock.c)
* axon_ram_make_request (arch/powerpc/sysdev/axonram.c)
* simdisk_make_request (arch/xtensa/platforms/iss/simdisk.c)
* brd_make_request (ramdisk - drivers/block/brd.c)
* mtip_submit_request (drivers/block/mtip32xx/mtip32xx.c)
* loop_make_request
* null_queue_bio
* bcache's make_request fns
Some others are almost certainly safe to remove now, but will be left
for future patches.
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ming Lei <ming.lei@canonical.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: dm-devel@redhat.com
Cc: Lars Ellenberg <drbd-dev@lists.linbit.com>
Cc: drbd-user@lists.linbit.com
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Jim Paris <jim@jtan.com>
Cc: Philip Kelleher <pjk1939@linux.vnet.ibm.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Oleg Drokin <oleg.drokin@intel.com>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Acked-by: NeilBrown <neilb@suse.de> (for the 'md/md.c' bits)
Acked-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
[dpark: skip more mq-based drivers, resolve merge conflicts, etc.]
Signed-off-by: Dongsu Park <dpark@posteo.net>
Signed-off-by: Ming Lin <ming.l@ssi.samsung.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/block/drbd/drbd_req.c | 2 | ||||
-rw-r--r-- | drivers/block/pktcdvd.c | 6 | ||||
-rw-r--r-- | drivers/block/ps3vram.c | 2 | ||||
-rw-r--r-- | drivers/block/rsxx/dev.c | 2 | ||||
-rw-r--r-- | drivers/block/umem.c | 2 | ||||
-rw-r--r-- | drivers/block/zram/zram_drv.c | 2 | ||||
-rw-r--r-- | drivers/md/dm.c | 2 | ||||
-rw-r--r-- | drivers/md/md.c | 2 | ||||
-rw-r--r-- | drivers/s390/block/dcssblk.c | 2 | ||||
-rw-r--r-- | drivers/s390/block/xpram.c | 2 | ||||
-rw-r--r-- | drivers/staging/lustre/lustre/llite/lloop.c | 2 |
11 files changed, 24 insertions, 2 deletions
diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c index 9cb4116..923c857 100644 --- a/drivers/block/drbd/drbd_req.c +++ b/drivers/block/drbd/drbd_req.c @@ -1499,6 +1499,8 @@ void drbd_make_request(struct request_queue *q, struct bio *bio) struct drbd_device *device = (struct drbd_device *) q->queuedata; unsigned long start_jif; + blk_queue_split(q, &bio, q->bio_split); + start_jif = jiffies; /* diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c index a7a259e..ee7ad5e 100644 --- a/drivers/block/pktcdvd.c +++ b/drivers/block/pktcdvd.c @@ -2447,6 +2447,10 @@ static void pkt_make_request(struct request_queue *q, struct bio *bio) char b[BDEVNAME_SIZE]; struct bio *split; + blk_queue_bounce(q, &bio); + + blk_queue_split(q, &bio, q->bio_split); + pd = q->queuedata; if (!pd) { pr_err("%s incorrect request queue\n", @@ -2477,8 +2481,6 @@ static void pkt_make_request(struct request_queue *q, struct bio *bio) goto end_io; } - blk_queue_bounce(q, &bio); - do { sector_t zone = get_zone(bio->bi_iter.bi_sector, pd); sector_t last_zone = get_zone(bio_end_sector(bio) - 1, pd); diff --git a/drivers/block/ps3vram.c b/drivers/block/ps3vram.c index 49b4706..d89fcac 100644 --- a/drivers/block/ps3vram.c +++ b/drivers/block/ps3vram.c @@ -606,6 +606,8 @@ static void ps3vram_make_request(struct request_queue *q, struct bio *bio) dev_dbg(&dev->core, "%s\n", __func__); + blk_queue_split(q, &bio, q->bio_split); + spin_lock_irq(&priv->lock); busy = !bio_list_empty(&priv->list); bio_list_add(&priv->list, bio); diff --git a/drivers/block/rsxx/dev.c b/drivers/block/rsxx/dev.c index 63b9d2f..3163e4cdc 100644 --- a/drivers/block/rsxx/dev.c +++ b/drivers/block/rsxx/dev.c @@ -151,6 +151,8 @@ static void rsxx_make_request(struct request_queue *q, struct bio *bio) struct rsxx_bio_meta *bio_meta; int st = -EINVAL; + blk_queue_split(q, &bio, q->bio_split); + might_sleep(); if (!card) diff --git a/drivers/block/umem.c b/drivers/block/umem.c index 3b3afd2..04d6579 100644 --- a/drivers/block/umem.c +++ b/drivers/block/umem.c @@ -531,6 +531,8 @@ static void mm_make_request(struct request_queue *q, struct bio *bio) (unsigned long long)bio->bi_iter.bi_sector, bio->bi_iter.bi_size); + blk_queue_split(q, &bio, q->bio_split); + spin_lock_irq(&card->lock); *card->biotail = bio; bio->bi_next = NULL; diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 68c3d48..aec781a 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -900,6 +900,8 @@ static void zram_make_request(struct request_queue *queue, struct bio *bio) if (unlikely(!zram_meta_get(zram))) goto error; + blk_queue_split(queue, &bio, queue->bio_split); + if (!valid_io_request(zram, bio->bi_iter.bi_sector, bio->bi_iter.bi_size)) { atomic64_inc(&zram->stats.invalid_io); diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 7f367fc..069f8d7 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1799,6 +1799,8 @@ static void dm_make_request(struct request_queue *q, struct bio *bio) map = dm_get_live_table(md, &srcu_idx); + blk_queue_split(q, &bio, q->bio_split); + generic_start_io_acct(rw, bio_sectors(bio), &dm_disk(md)->part0); /* if we're suspended, we have to queue this io for later */ diff --git a/drivers/md/md.c b/drivers/md/md.c index ac4381a..e1d8723 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -257,6 +257,8 @@ static void md_make_request(struct request_queue *q, struct bio *bio) unsigned int sectors; int cpu; + blk_queue_split(q, &bio, q->bio_split); + if (mddev == NULL || mddev->pers == NULL || !mddev->ready) { bio_io_error(bio); diff --git a/drivers/s390/block/dcssblk.c b/drivers/s390/block/dcssblk.c index 8bcb822..29ea239 100644 --- a/drivers/s390/block/dcssblk.c +++ b/drivers/s390/block/dcssblk.c @@ -826,6 +826,8 @@ dcssblk_make_request(struct request_queue *q, struct bio *bio) unsigned long source_addr; unsigned long bytes_done; + blk_queue_split(q, &bio, q->bio_split); + bytes_done = 0; dev_info = bio->bi_bdev->bd_disk->private_data; if (dev_info == NULL) diff --git a/drivers/s390/block/xpram.c b/drivers/s390/block/xpram.c index 93856b9..02871f1 100644 --- a/drivers/s390/block/xpram.c +++ b/drivers/s390/block/xpram.c @@ -190,6 +190,8 @@ static void xpram_make_request(struct request_queue *q, struct bio *bio) unsigned long page_addr; unsigned long bytes; + blk_queue_split(q, &bio, q->bio_split); + if ((bio->bi_iter.bi_sector & 7) != 0 || (bio->bi_iter.bi_size & 4095) != 0) /* Request is not page-aligned. */ diff --git a/drivers/staging/lustre/lustre/llite/lloop.c b/drivers/staging/lustre/lustre/llite/lloop.c index cc00fd1..1e33d54 100644 --- a/drivers/staging/lustre/lustre/llite/lloop.c +++ b/drivers/staging/lustre/lustre/llite/lloop.c @@ -340,6 +340,8 @@ static void loop_make_request(struct request_queue *q, struct bio *old_bio) int rw = bio_rw(old_bio); int inactive; + blk_queue_split(q, &old_bio, q->bio_split); + if (!lo) goto err; |