* [PATCH 1/2] md: add new interface 'mk_rq' in target_type @ 2012-09-20 3:18 Robin Dong 2012-09-20 3:18 ` [PATCH 2/2] md: modify dm_io() so it could return bios instead of submitting it Robin Dong 2012-11-14 3:08 ` [PATCH 1/2] md: add new interface 'mk_rq' in target_type Robin Dong 0 siblings, 2 replies; 5+ messages in thread From: Robin Dong @ 2012-09-20 3:18 UTC (permalink / raw) To: linux-kernel, dm-devel; +Cc: Robin Dong From: Robin Dong <sanbai@taobao.com> We are now trying to modify flashcache(https://github.com/facebook/flashcache) to make it request based so that we can let cfq io-controller control the bandwidth between different io cgroups. A search in the dm directory tells me that only multipath is a request based dm target and its functionality is very simple and map_rq() is used to map the request to different underlying devices. We can't work in this way because: 1. the request which processed by map_rq() need to be issued to different lower devices (disk device and cache device, in flashcache), therefore the request can't be totally remapped by simply changing its queue and returning DM_MAPIO_REMAPPED in map_rq() like multipath_map() 2. to submit bios drectly in map_rq() (by return DM_MAPIO_SUBMITTED) will cause BUG_ON(!irqs_disabled()) in dm_request_fn() because the submit_bio()->generic_make_request()->blk_queue_bio() will definitly call spin_unlock_irq to enable the irqs As above,the interface map_rq() provided by devcie-mapper framework is not enough for an autonomous target, like flashcache. We propose to add a new mk_rq interface so that we can make the requests by ourselves. Signed-off-by: Robin Dong <sanbai@taobao.com> --- drivers/md/dm-io.c | 58 ++++++++++++++++++++++++++++-------------------- drivers/md/dm-log.c | 1 + include/linux/dm-io.h | 3 ++ 3 files changed, 38 insertions(+), 24 deletions(-) diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c index ea5dd28..f767792 100644 --- a/drivers/md/dm-io.c +++ b/drivers/md/dm-io.c @@ -287,8 +287,8 @@ static void km_dp_init(struct dpages *dp, void *data) /*----------------------------------------------------------------- * IO routines that accept a list of pages. *---------------------------------------------------------------*/ -static void do_region(int rw, unsigned region, struct dm_io_region *where, - struct dpages *dp, struct io *io) +static void do_region(struct dm_io_request *io_req, unsigned region, + struct dm_io_region *where, struct dpages *dp, struct io *io) { struct bio *bio; struct page *page; @@ -298,6 +298,7 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where, sector_t remaining = where->count; struct request_queue *q = bdev_get_queue(where->bdev); sector_t discard_sectors; + int rw = io_req->bi_rw; /* * where->count may be zero if rw holds a flush and we need to @@ -339,15 +340,26 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where, } atomic_inc(&io->count); - submit_bio(rw, bio); + if (!io_req->only_create_bio) + submit_bio(rw, bio); + else { + bio->bi_rw |= rw; + if (io_req->start) { + io_req->end->bi_next = bio; + io_req->end = bio; + } else + io_req->start = io_req->end = bio; + bio->bi_next = NULL; + } } while (remaining); } -static void dispatch_io(int rw, unsigned int num_regions, +static void dispatch_io(struct dm_io_request *io_req, unsigned int num_regions, struct dm_io_region *where, struct dpages *dp, struct io *io, int sync) { int i; + int rw = io_req->bi_rw; struct dpages old_pages = *dp; BUG_ON(num_regions > DM_IO_MAX_REGIONS); @@ -362,7 +374,7 @@ static void dispatch_io(int rw, unsigned int num_regions, for (i = 0; i < num_regions; i++) { *dp = old_pages; if (where[i].count || (rw & REQ_FLUSH)) - do_region(rw, i, where + i, dp, io); + do_region(io_req, i, where + i, dp, io); } /* @@ -372,8 +384,8 @@ static void dispatch_io(int rw, unsigned int num_regions, dec_count(io, 0, 0); } -static int sync_io(struct dm_io_client *client, unsigned int num_regions, - struct dm_io_region *where, int rw, struct dpages *dp, +static int sync_io(struct dm_io_request *io_req, unsigned int num_regions, + struct dm_io_region *where, struct dpages *dp, unsigned long *error_bits) { /* @@ -385,7 +397,7 @@ static int sync_io(struct dm_io_client *client, unsigned int num_regions, volatile char io_[sizeof(struct io) + __alignof__(struct io) - 1]; struct io *io = (struct io *)PTR_ALIGN(&io_, __alignof__(struct io)); - if (num_regions > 1 && (rw & RW_MASK) != WRITE) { + if (num_regions > 1 && (io_req->bi_rw & RW_MASK) != WRITE) { WARN_ON(1); return -EIO; } @@ -393,12 +405,12 @@ static int sync_io(struct dm_io_client *client, unsigned int num_regions, io->error_bits = 0; atomic_set(&io->count, 1); /* see dispatch_io() */ io->sleeper = current; - io->client = client; + io->client = io_req->client; io->vma_invalidate_address = dp->vma_invalidate_address; io->vma_invalidate_size = dp->vma_invalidate_size; - dispatch_io(rw, num_regions, where, dp, io, 1); + dispatch_io(io_req, num_regions, where, dp, io, 1); while (1) { set_current_state(TASK_UNINTERRUPTIBLE); @@ -416,30 +428,29 @@ static int sync_io(struct dm_io_client *client, unsigned int num_regions, return io->error_bits ? -EIO : 0; } -static int async_io(struct dm_io_client *client, unsigned int num_regions, - struct dm_io_region *where, int rw, struct dpages *dp, - io_notify_fn fn, void *context) +static int async_io(struct dm_io_request *io_req, unsigned int num_regions, + struct dm_io_region *where, struct dpages *dp) { struct io *io; - if (num_regions > 1 && (rw & RW_MASK) != WRITE) { + if (num_regions > 1 && (io_req->bi_rw & RW_MASK) != WRITE) { WARN_ON(1); - fn(1, context); + io_req->notify.fn(1, io_req->notify.context); return -EIO; } - io = mempool_alloc(client->pool, GFP_NOIO); + io = mempool_alloc(io_req->client->pool, GFP_NOIO); io->error_bits = 0; atomic_set(&io->count, 1); /* see dispatch_io() */ io->sleeper = NULL; - io->client = client; - io->callback = fn; - io->context = context; + io->client = io_req->client; + io->callback = io_req->notify.fn; + io->context = io_req->notify.context; io->vma_invalidate_address = dp->vma_invalidate_address; io->vma_invalidate_size = dp->vma_invalidate_size; - dispatch_io(rw, num_regions, where, dp, io, 0); + dispatch_io(io_req, num_regions, where, dp, io, 0); return 0; } @@ -499,11 +510,10 @@ int dm_io(struct dm_io_request *io_req, unsigned num_regions, return r; if (!io_req->notify.fn) - return sync_io(io_req->client, num_regions, where, - io_req->bi_rw, &dp, sync_error_bits); + return sync_io(io_req, num_regions, where, + &dp, sync_error_bits); - return async_io(io_req->client, num_regions, where, io_req->bi_rw, - &dp, io_req->notify.fn, io_req->notify.context); + return async_io(io_req, num_regions, where, &dp); } EXPORT_SYMBOL(dm_io); diff --git a/drivers/md/dm-log.c b/drivers/md/dm-log.c index 627d191..3bf065a 100644 --- a/drivers/md/dm-log.c +++ b/drivers/md/dm-log.c @@ -463,6 +463,7 @@ static int create_log_context(struct dm_dirty_log *log, struct dm_target *ti, kfree(lc); return r; } + lc->io_req.only_create_bio = 0; lc->disk_header = vmalloc(buf_size); if (!lc->disk_header) { diff --git a/include/linux/dm-io.h b/include/linux/dm-io.h index f4b0aa3..8782163 100644 --- a/include/linux/dm-io.h +++ b/include/linux/dm-io.h @@ -61,6 +61,9 @@ struct dm_io_request { struct dm_io_memory mem; /* Memory to use for io */ struct dm_io_notify notify; /* Synchronous if notify.fn is NULL */ struct dm_io_client *client; /* Client memory handler */ + int only_create_bio; + struct bio *start; + struct bio *end; }; /* -- 1.7.1 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH 2/2] md: modify dm_io() so it could return bios instead of submitting it 2012-09-20 3:18 [PATCH 1/2] md: add new interface 'mk_rq' in target_type Robin Dong @ 2012-09-20 3:18 ` Robin Dong 2012-11-14 3:08 ` Robin Dong 2012-11-14 3:08 ` [PATCH 1/2] md: add new interface 'mk_rq' in target_type Robin Dong 1 sibling, 1 reply; 5+ messages in thread From: Robin Dong @ 2012-09-20 3:18 UTC (permalink / raw) To: linux-kernel, dm-devel; +Cc: Robin Dong From: Robin Dong <sanbai@taobao.com> When trying to modify flashcache to request based (current it's bio based), we need to make request from bios by ourselves, but dm_io() will submit these bios directly, so we propose to modify the dm_io() to return bios instead of submiting it. This could also improve the flexibility of dm_io(). Signed-off-by: Robin Dong <sanbai@taobao.com> --- drivers/md/dm.c | 11 +++++++++++ include/linux/device-mapper.h | 3 +++ 2 files changed, 14 insertions(+), 0 deletions(-) diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 4e09b6f..bf6e3bb 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1459,11 +1459,22 @@ static int dm_request_based(struct mapped_device *md) static void dm_request(struct request_queue *q, struct bio *bio) { struct mapped_device *md = q->queuedata; + struct dm_table *map = dm_get_live_table(md); + struct dm_target *ti = dm_table_find_target(map, bio->bi_sector); + + if (ti->type->mk_rq) { + ti->type->mk_rq(ti, q, bio); + goto out; + } if (dm_request_based(md)) blk_queue_bio(q, bio); else _dm_request(q, bio); + +out: + dm_table_put(map); + return; } void dm_dispatch_request(struct request *rq) diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index 38d27a1..2386389 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -50,6 +50,8 @@ typedef int (*dm_map_fn) (struct dm_target *ti, struct bio *bio, union map_info *map_context); typedef int (*dm_map_request_fn) (struct dm_target *ti, struct request *clone, union map_info *map_context); +typedef int (*dm_make_request_fn) (struct dm_target *ti, + struct request_queue *q, struct bio *bio); /* * Returns: @@ -136,6 +138,7 @@ struct target_type { dm_dtr_fn dtr; dm_map_fn map; dm_map_request_fn map_rq; + dm_make_request_fn mk_rq; dm_endio_fn end_io; dm_request_endio_fn rq_end_io; dm_presuspend_fn presuspend; -- 1.7.1 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH 2/2] md: modify dm_io() so it could return bios instead of submitting it 2012-09-20 3:18 ` [PATCH 2/2] md: modify dm_io() so it could return bios instead of submitting it Robin Dong @ 2012-11-14 3:08 ` Robin Dong 0 siblings, 0 replies; 5+ messages in thread From: Robin Dong @ 2012-11-14 3:08 UTC (permalink / raw) To: linux-kernel, dm-devel ping 2012/9/20 Robin Dong <robin.k.dong@gmail.com>: > From: Robin Dong <sanbai@taobao.com> > > When trying to modify flashcache to request based (current it's bio based), we need > to make request from bios by ourselves, but dm_io() will submit these bios directly, > so we propose to modify the dm_io() to return bios instead of submiting it. > > This could also improve the flexibility of dm_io(). > > Signed-off-by: Robin Dong <sanbai@taobao.com> > --- > drivers/md/dm.c | 11 +++++++++++ > include/linux/device-mapper.h | 3 +++ > 2 files changed, 14 insertions(+), 0 deletions(-) > > diff --git a/drivers/md/dm.c b/drivers/md/dm.c > index 4e09b6f..bf6e3bb 100644 > --- a/drivers/md/dm.c > +++ b/drivers/md/dm.c > @@ -1459,11 +1459,22 @@ static int dm_request_based(struct mapped_device *md) > static void dm_request(struct request_queue *q, struct bio *bio) > { > struct mapped_device *md = q->queuedata; > + struct dm_table *map = dm_get_live_table(md); > + struct dm_target *ti = dm_table_find_target(map, bio->bi_sector); > + > + if (ti->type->mk_rq) { > + ti->type->mk_rq(ti, q, bio); > + goto out; > + } > > if (dm_request_based(md)) > blk_queue_bio(q, bio); > else > _dm_request(q, bio); > + > +out: > + dm_table_put(map); > + return; > } > > void dm_dispatch_request(struct request *rq) > diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h > index 38d27a1..2386389 100644 > --- a/include/linux/device-mapper.h > +++ b/include/linux/device-mapper.h > @@ -50,6 +50,8 @@ typedef int (*dm_map_fn) (struct dm_target *ti, struct bio *bio, > union map_info *map_context); > typedef int (*dm_map_request_fn) (struct dm_target *ti, struct request *clone, > union map_info *map_context); > +typedef int (*dm_make_request_fn) (struct dm_target *ti, > + struct request_queue *q, struct bio *bio); > > /* > * Returns: > @@ -136,6 +138,7 @@ struct target_type { > dm_dtr_fn dtr; > dm_map_fn map; > dm_map_request_fn map_rq; > + dm_make_request_fn mk_rq; > dm_endio_fn end_io; > dm_request_endio_fn rq_end_io; > dm_presuspend_fn presuspend; > -- > 1.7.1 > -- -- Best Regard Robin Dong ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH 1/2] md: add new interface 'mk_rq' in target_type 2012-09-20 3:18 [PATCH 1/2] md: add new interface 'mk_rq' in target_type Robin Dong 2012-09-20 3:18 ` [PATCH 2/2] md: modify dm_io() so it could return bios instead of submitting it Robin Dong @ 2012-11-14 3:08 ` Robin Dong 1 sibling, 0 replies; 5+ messages in thread From: Robin Dong @ 2012-11-14 3:08 UTC (permalink / raw) To: linux-kernel, dm-devel ping 2012/9/20 Robin Dong <robin.k.dong@gmail.com>: > From: Robin Dong <sanbai@taobao.com> > > We are now trying to modify flashcache(https://github.com/facebook/flashcache) > to make it request based so that > we can let cfq io-controller control the bandwidth between different > io cgroups. > > A search in the dm directory tells me that only multipath is a request > based dm target and its functionality > is very simple and map_rq() is used to map the request to different underlying devices. > We can't work in this way because: > > 1. the request which processed by map_rq() need to be issued to > different lower devices (disk device and cache device, in flashcache), therefore the request > can't be totally remapped by simply changing its queue and returning DM_MAPIO_REMAPPED in map_rq() like multipath_map() > 2. to submit bios drectly in map_rq() (by return DM_MAPIO_SUBMITTED) will cause BUG_ON(!irqs_disabled()) > in dm_request_fn() because the submit_bio()->generic_make_request()->blk_queue_bio() will definitly call spin_unlock_irq to enable the irqs > > As above,the interface map_rq() provided by devcie-mapper framework > is not enough for an autonomous target, like flashcache. > > We propose to add a new > mk_rq interface so that we can make the requests > by ourselves. > > Signed-off-by: Robin Dong <sanbai@taobao.com> > --- > drivers/md/dm-io.c | 58 ++++++++++++++++++++++++++++-------------------- > drivers/md/dm-log.c | 1 + > include/linux/dm-io.h | 3 ++ > 3 files changed, 38 insertions(+), 24 deletions(-) > > diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c > index ea5dd28..f767792 100644 > --- a/drivers/md/dm-io.c > +++ b/drivers/md/dm-io.c > @@ -287,8 +287,8 @@ static void km_dp_init(struct dpages *dp, void *data) > /*----------------------------------------------------------------- > * IO routines that accept a list of pages. > *---------------------------------------------------------------*/ > -static void do_region(int rw, unsigned region, struct dm_io_region *where, > - struct dpages *dp, struct io *io) > +static void do_region(struct dm_io_request *io_req, unsigned region, > + struct dm_io_region *where, struct dpages *dp, struct io *io) > { > struct bio *bio; > struct page *page; > @@ -298,6 +298,7 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where, > sector_t remaining = where->count; > struct request_queue *q = bdev_get_queue(where->bdev); > sector_t discard_sectors; > + int rw = io_req->bi_rw; > > /* > * where->count may be zero if rw holds a flush and we need to > @@ -339,15 +340,26 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where, > } > > atomic_inc(&io->count); > - submit_bio(rw, bio); > + if (!io_req->only_create_bio) > + submit_bio(rw, bio); > + else { > + bio->bi_rw |= rw; > + if (io_req->start) { > + io_req->end->bi_next = bio; > + io_req->end = bio; > + } else > + io_req->start = io_req->end = bio; > + bio->bi_next = NULL; > + } > } while (remaining); > } > > -static void dispatch_io(int rw, unsigned int num_regions, > +static void dispatch_io(struct dm_io_request *io_req, unsigned int num_regions, > struct dm_io_region *where, struct dpages *dp, > struct io *io, int sync) > { > int i; > + int rw = io_req->bi_rw; > struct dpages old_pages = *dp; > > BUG_ON(num_regions > DM_IO_MAX_REGIONS); > @@ -362,7 +374,7 @@ static void dispatch_io(int rw, unsigned int num_regions, > for (i = 0; i < num_regions; i++) { > *dp = old_pages; > if (where[i].count || (rw & REQ_FLUSH)) > - do_region(rw, i, where + i, dp, io); > + do_region(io_req, i, where + i, dp, io); > } > > /* > @@ -372,8 +384,8 @@ static void dispatch_io(int rw, unsigned int num_regions, > dec_count(io, 0, 0); > } > > -static int sync_io(struct dm_io_client *client, unsigned int num_regions, > - struct dm_io_region *where, int rw, struct dpages *dp, > +static int sync_io(struct dm_io_request *io_req, unsigned int num_regions, > + struct dm_io_region *where, struct dpages *dp, > unsigned long *error_bits) > { > /* > @@ -385,7 +397,7 @@ static int sync_io(struct dm_io_client *client, unsigned int num_regions, > volatile char io_[sizeof(struct io) + __alignof__(struct io) - 1]; > struct io *io = (struct io *)PTR_ALIGN(&io_, __alignof__(struct io)); > > - if (num_regions > 1 && (rw & RW_MASK) != WRITE) { > + if (num_regions > 1 && (io_req->bi_rw & RW_MASK) != WRITE) { > WARN_ON(1); > return -EIO; > } > @@ -393,12 +405,12 @@ static int sync_io(struct dm_io_client *client, unsigned int num_regions, > io->error_bits = 0; > atomic_set(&io->count, 1); /* see dispatch_io() */ > io->sleeper = current; > - io->client = client; > + io->client = io_req->client; > > io->vma_invalidate_address = dp->vma_invalidate_address; > io->vma_invalidate_size = dp->vma_invalidate_size; > > - dispatch_io(rw, num_regions, where, dp, io, 1); > + dispatch_io(io_req, num_regions, where, dp, io, 1); > > while (1) { > set_current_state(TASK_UNINTERRUPTIBLE); > @@ -416,30 +428,29 @@ static int sync_io(struct dm_io_client *client, unsigned int num_regions, > return io->error_bits ? -EIO : 0; > } > > -static int async_io(struct dm_io_client *client, unsigned int num_regions, > - struct dm_io_region *where, int rw, struct dpages *dp, > - io_notify_fn fn, void *context) > +static int async_io(struct dm_io_request *io_req, unsigned int num_regions, > + struct dm_io_region *where, struct dpages *dp) > { > struct io *io; > > - if (num_regions > 1 && (rw & RW_MASK) != WRITE) { > + if (num_regions > 1 && (io_req->bi_rw & RW_MASK) != WRITE) { > WARN_ON(1); > - fn(1, context); > + io_req->notify.fn(1, io_req->notify.context); > return -EIO; > } > > - io = mempool_alloc(client->pool, GFP_NOIO); > + io = mempool_alloc(io_req->client->pool, GFP_NOIO); > io->error_bits = 0; > atomic_set(&io->count, 1); /* see dispatch_io() */ > io->sleeper = NULL; > - io->client = client; > - io->callback = fn; > - io->context = context; > + io->client = io_req->client; > + io->callback = io_req->notify.fn; > + io->context = io_req->notify.context; > > io->vma_invalidate_address = dp->vma_invalidate_address; > io->vma_invalidate_size = dp->vma_invalidate_size; > > - dispatch_io(rw, num_regions, where, dp, io, 0); > + dispatch_io(io_req, num_regions, where, dp, io, 0); > return 0; > } > > @@ -499,11 +510,10 @@ int dm_io(struct dm_io_request *io_req, unsigned num_regions, > return r; > > if (!io_req->notify.fn) > - return sync_io(io_req->client, num_regions, where, > - io_req->bi_rw, &dp, sync_error_bits); > + return sync_io(io_req, num_regions, where, > + &dp, sync_error_bits); > > - return async_io(io_req->client, num_regions, where, io_req->bi_rw, > - &dp, io_req->notify.fn, io_req->notify.context); > + return async_io(io_req, num_regions, where, &dp); > } > EXPORT_SYMBOL(dm_io); > > diff --git a/drivers/md/dm-log.c b/drivers/md/dm-log.c > index 627d191..3bf065a 100644 > --- a/drivers/md/dm-log.c > +++ b/drivers/md/dm-log.c > @@ -463,6 +463,7 @@ static int create_log_context(struct dm_dirty_log *log, struct dm_target *ti, > kfree(lc); > return r; > } > + lc->io_req.only_create_bio = 0; > > lc->disk_header = vmalloc(buf_size); > if (!lc->disk_header) { > diff --git a/include/linux/dm-io.h b/include/linux/dm-io.h > index f4b0aa3..8782163 100644 > --- a/include/linux/dm-io.h > +++ b/include/linux/dm-io.h > @@ -61,6 +61,9 @@ struct dm_io_request { > struct dm_io_memory mem; /* Memory to use for io */ > struct dm_io_notify notify; /* Synchronous if notify.fn is NULL */ > struct dm_io_client *client; /* Client memory handler */ > + int only_create_bio; > + struct bio *start; > + struct bio *end; > }; > > /* > -- > 1.7.1 > -- -- Best Regard Robin Dong ^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH 1/2] md: add new interface 'mk_rq' in target_type @ 2012-09-03 2:12 Robin Dong 2012-09-03 2:12 ` [PATCH 2/2] md: modify dm_io() so it could return bios instead of submitting it Robin Dong 0 siblings, 1 reply; 5+ messages in thread From: Robin Dong @ 2012-09-03 2:12 UTC (permalink / raw) To: dm-devel, linux-kernel; +Cc: Robin Dong From: Robin Dong <sanbai@taobao.com> We are now trying to modify flashcache(https://github.com/facebook/flashcache) to make it request based so that we can let cfq io-controller control the bandwidth between different io cgroups. A search in the dm directory tells me that only multipath is a request based dm target and its functionality is very simple and map_rq() is used to map the request to different underlying devices. We can't work in this way because: 1. the request which processed by map_rq() need to be issued to different lower devices (disk device and cache device, in flashcache), therefore the request can't be totally remapped by simply changing its queue and returning DM_MAPIO_REMAPPED in map_rq() like multipath_map() 2. to submit bios drectly in map_rq() (by return DM_MAPIO_SUBMITTED) will cause BUG_ON(!irqs_disabled()) in dm_request_fn() because the submit_bio()->generic_make_request()->blk_queue_bio() will definitly call spin_unlock_irq to enable the irqs As above,the interface map_rq() provided by devcie-mapper framework is not enough for an autonomous target, like flashcache. We propose to add a new mk_rq interface so that we can make the requests by ourselves. Signed-off-by: Robin Dong <sanbai@taobao.com> --- drivers/md/dm.c | 10 ++++++++++ include/linux/device-mapper.h | 3 +++ 2 files changed, 13 insertions(+), 0 deletions(-) diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 4e09b6f..3ae67de 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1459,11 +1459,21 @@ static int dm_request_based(struct mapped_device *md) static void dm_request(struct request_queue *q, struct bio *bio) { struct mapped_device *md = q->queuedata; + struct dm_table *map = dm_get_live_table(md); + struct dm_target *ti = dm_table_find_target(map, bio->bi_sector); + + if (ti->type->mk_rq) { + ti->type->mk_rq(ti, q, bio); + goto out; + } if (dm_request_based(md)) blk_queue_bio(q, bio); else _dm_request(q, bio); + +out: + dm_table_put(map); } void dm_dispatch_request(struct request *rq) diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index 38d27a1..2386389 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -50,6 +50,8 @@ typedef int (*dm_map_fn) (struct dm_target *ti, struct bio *bio, union map_info *map_context); typedef int (*dm_map_request_fn) (struct dm_target *ti, struct request *clone, union map_info *map_context); +typedef int (*dm_make_request_fn) (struct dm_target *ti, + struct request_queue *q, struct bio *bio); /* * Returns: @@ -136,6 +138,7 @@ struct target_type { dm_dtr_fn dtr; dm_map_fn map; dm_map_request_fn map_rq; + dm_make_request_fn mk_rq; dm_endio_fn end_io; dm_request_endio_fn rq_end_io; dm_presuspend_fn presuspend; -- 1.7.1 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH 2/2] md: modify dm_io() so it could return bios instead of submitting it 2012-09-03 2:12 Robin Dong @ 2012-09-03 2:12 ` Robin Dong 0 siblings, 0 replies; 5+ messages in thread From: Robin Dong @ 2012-09-03 2:12 UTC (permalink / raw) To: dm-devel, linux-kernel; +Cc: Robin Dong From: Robin Dong <sanbai@taobao.com> When trying to modify flashcache to request based (current it's bio based), we need to make request from bios by ourselves, but dm_io() will submit these bios directly, so we propose to modify the dm_io() to return bios instead of submiting it. This could also improve the flexibility of dm_io(). Signed-off-by: Robin Dong <sanbai@taobao.com> --- drivers/md/dm-bufio.c | 2 + drivers/md/dm-io.c | 58 +++++++++++++++++++++++---------------- drivers/md/dm-kcopyd.c | 1 + drivers/md/dm-log.c | 1 + drivers/md/dm-raid1.c | 3 ++ drivers/md/dm-snap-persistent.c | 1 + include/linux/dm-io.h | 3 ++ 7 files changed, 45 insertions(+), 24 deletions(-) diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c index cc06a1e..f5867b9 100644 --- a/drivers/md/dm-bufio.c +++ b/drivers/md/dm-bufio.c @@ -487,6 +487,7 @@ static void use_dmio(struct dm_buffer *b, int rw, sector_t block, .notify.fn = dmio_complete, .notify.context = b, .client = b->c->dm_io, + .submit_bio = 1, }; struct dm_io_region region = { .bdev = b->c->bdev, @@ -1200,6 +1201,7 @@ int dm_bufio_issue_flush(struct dm_bufio_client *c) .mem.type = DM_IO_KMEM, .mem.ptr.addr = NULL, .client = c->dm_io, + .submit_bio = 1, }; struct dm_io_region io_reg = { .bdev = c->bdev, diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c index ea5dd28..f235182 100644 --- a/drivers/md/dm-io.c +++ b/drivers/md/dm-io.c @@ -287,8 +287,8 @@ static void km_dp_init(struct dpages *dp, void *data) /*----------------------------------------------------------------- * IO routines that accept a list of pages. *---------------------------------------------------------------*/ -static void do_region(int rw, unsigned region, struct dm_io_region *where, - struct dpages *dp, struct io *io) +static void do_region(struct dm_io_request *io_req, unsigned region, + struct dm_io_region *where, struct dpages *dp, struct io *io) { struct bio *bio; struct page *page; @@ -298,6 +298,7 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where, sector_t remaining = where->count; struct request_queue *q = bdev_get_queue(where->bdev); sector_t discard_sectors; + int rw = io_req->bi_rw; /* * where->count may be zero if rw holds a flush and we need to @@ -339,15 +340,26 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where, } atomic_inc(&io->count); - submit_bio(rw, bio); + if (io_req->submit_bio) + submit_bio(rw, bio); + else { + bio->bi_rw |= rw; + if (io_req->start) { + io_req->end->bi_next = bio; + io_req->end = bio; + } else + io_req->start = io_req->end = bio; + bio->bi_next = NULL; + } } while (remaining); } -static void dispatch_io(int rw, unsigned int num_regions, +static void dispatch_io(struct dm_io_request *io_req, unsigned int num_regions, struct dm_io_region *where, struct dpages *dp, struct io *io, int sync) { int i; + int rw = io_req->bi_rw; struct dpages old_pages = *dp; BUG_ON(num_regions > DM_IO_MAX_REGIONS); @@ -362,7 +374,7 @@ static void dispatch_io(int rw, unsigned int num_regions, for (i = 0; i < num_regions; i++) { *dp = old_pages; if (where[i].count || (rw & REQ_FLUSH)) - do_region(rw, i, where + i, dp, io); + do_region(io_req, i, where + i, dp, io); } /* @@ -372,8 +384,8 @@ static void dispatch_io(int rw, unsigned int num_regions, dec_count(io, 0, 0); } -static int sync_io(struct dm_io_client *client, unsigned int num_regions, - struct dm_io_region *where, int rw, struct dpages *dp, +static int sync_io(struct dm_io_request *io_req, unsigned int num_regions, + struct dm_io_region *where, struct dpages *dp, unsigned long *error_bits) { /* @@ -385,7 +397,7 @@ static int sync_io(struct dm_io_client *client, unsigned int num_regions, volatile char io_[sizeof(struct io) + __alignof__(struct io) - 1]; struct io *io = (struct io *)PTR_ALIGN(&io_, __alignof__(struct io)); - if (num_regions > 1 && (rw & RW_MASK) != WRITE) { + if (num_regions > 1 && (io_req->bi_rw & RW_MASK) != WRITE) { WARN_ON(1); return -EIO; } @@ -393,12 +405,12 @@ static int sync_io(struct dm_io_client *client, unsigned int num_regions, io->error_bits = 0; atomic_set(&io->count, 1); /* see dispatch_io() */ io->sleeper = current; - io->client = client; + io->client = io_req->client; io->vma_invalidate_address = dp->vma_invalidate_address; io->vma_invalidate_size = dp->vma_invalidate_size; - dispatch_io(rw, num_regions, where, dp, io, 1); + dispatch_io(io_req, num_regions, where, dp, io, 1); while (1) { set_current_state(TASK_UNINTERRUPTIBLE); @@ -416,30 +428,29 @@ static int sync_io(struct dm_io_client *client, unsigned int num_regions, return io->error_bits ? -EIO : 0; } -static int async_io(struct dm_io_client *client, unsigned int num_regions, - struct dm_io_region *where, int rw, struct dpages *dp, - io_notify_fn fn, void *context) +static int async_io(struct dm_io_request *io_req, unsigned int num_regions, + struct dm_io_region *where, struct dpages *dp) { struct io *io; - if (num_regions > 1 && (rw & RW_MASK) != WRITE) { + if (num_regions > 1 && (io_req->bi_rw & RW_MASK) != WRITE) { WARN_ON(1); - fn(1, context); + io_req->notify.fn(1, io_req->notify.context); return -EIO; } - io = mempool_alloc(client->pool, GFP_NOIO); + io = mempool_alloc(io_req->client->pool, GFP_NOIO); io->error_bits = 0; atomic_set(&io->count, 1); /* see dispatch_io() */ io->sleeper = NULL; - io->client = client; - io->callback = fn; - io->context = context; + io->client = io_req->client; + io->callback = io_req->notify.fn; + io->context = io_req->notify.context; io->vma_invalidate_address = dp->vma_invalidate_address; io->vma_invalidate_size = dp->vma_invalidate_size; - dispatch_io(rw, num_regions, where, dp, io, 0); + dispatch_io(io_req, num_regions, where, dp, io, 0); return 0; } @@ -499,11 +510,10 @@ int dm_io(struct dm_io_request *io_req, unsigned num_regions, return r; if (!io_req->notify.fn) - return sync_io(io_req->client, num_regions, where, - io_req->bi_rw, &dp, sync_error_bits); + return sync_io(io_req, num_regions, where, + &dp, sync_error_bits); - return async_io(io_req->client, num_regions, where, io_req->bi_rw, - &dp, io_req->notify.fn, io_req->notify.context); + return async_io(io_req, num_regions, where, &dp); } EXPORT_SYMBOL(dm_io); diff --git a/drivers/md/dm-kcopyd.c b/drivers/md/dm-kcopyd.c index bed444c..6a8ecc9 100644 --- a/drivers/md/dm-kcopyd.c +++ b/drivers/md/dm-kcopyd.c @@ -387,6 +387,7 @@ static int run_io_job(struct kcopyd_job *job) .notify.fn = complete_io, .notify.context = job, .client = job->kc->io_client, + .submit_bio = 1, }; if (job->rw == READ) diff --git a/drivers/md/dm-log.c b/drivers/md/dm-log.c index 627d191..8425e84 100644 --- a/drivers/md/dm-log.c +++ b/drivers/md/dm-log.c @@ -463,6 +463,7 @@ static int create_log_context(struct dm_dirty_log *log, struct dm_target *ti, kfree(lc); return r; } + lc->io_req.submit_bio = 1; lc->disk_header = vmalloc(buf_size); if (!lc->disk_header) { diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c index bc5ddba..338d726 100644 --- a/drivers/md/dm-raid1.c +++ b/drivers/md/dm-raid1.c @@ -261,6 +261,7 @@ static int mirror_flush(struct dm_target *ti) .mem.type = DM_IO_KMEM, .mem.ptr.addr = NULL, .client = ms->io_client, + .submit_bio = 1, }; for (i = 0, m = ms->mirror; i < ms->nr_mirrors; i++, m++) { @@ -530,6 +531,7 @@ static void read_async_bio(struct mirror *m, struct bio *bio) .notify.fn = read_callback, .notify.context = bio, .client = m->ms->io_client, + .submit_bio = 1, }; map_region(&io, m, bio); @@ -633,6 +635,7 @@ static void do_write(struct mirror_set *ms, struct bio *bio) .notify.fn = write_callback, .notify.context = bio, .client = ms->io_client, + .submit_bio = 1, }; if (bio->bi_rw & REQ_DISCARD) { diff --git a/drivers/md/dm-snap-persistent.c b/drivers/md/dm-snap-persistent.c index 3ac4156..0600e1d 100644 --- a/drivers/md/dm-snap-persistent.c +++ b/drivers/md/dm-snap-persistent.c @@ -241,6 +241,7 @@ static int chunk_io(struct pstore *ps, void *area, chunk_t chunk, int rw, .mem.ptr.vma = area, .client = ps->io_client, .notify.fn = NULL, + .submit_bio = 1, }; struct mdata_req req; diff --git a/include/linux/dm-io.h b/include/linux/dm-io.h index f4b0aa3..45f576b 100644 --- a/include/linux/dm-io.h +++ b/include/linux/dm-io.h @@ -61,6 +61,9 @@ struct dm_io_request { struct dm_io_memory mem; /* Memory to use for io */ struct dm_io_notify notify; /* Synchronous if notify.fn is NULL */ struct dm_io_client *client; /* Client memory handler */ + int submit_bio; + struct bio *start; + struct bio *end; }; /* -- 1.7.1 ^ permalink raw reply related [flat|nested] 5+ messages in thread
end of thread, other threads:[~2012-11-14 3:08 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2012-09-20 3:18 [PATCH 1/2] md: add new interface 'mk_rq' in target_type Robin Dong 2012-09-20 3:18 ` [PATCH 2/2] md: modify dm_io() so it could return bios instead of submitting it Robin Dong 2012-11-14 3:08 ` Robin Dong 2012-11-14 3:08 ` [PATCH 1/2] md: add new interface 'mk_rq' in target_type Robin Dong -- strict thread matches above, loose matches on Subject: below -- 2012-09-03 2:12 Robin Dong 2012-09-03 2:12 ` [PATCH 2/2] md: modify dm_io() so it could return bios instead of submitting it Robin Dong
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