diff options
| -rw-r--r-- | drivers/md/dm.c | 79 |
1 files changed, 67 insertions, 12 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 9ca012e..6617ce4 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -71,6 +71,19 @@ union map_info *dm_get_mapinfo(struct bio *bio) #define DMF_DELETING 4 #define DMF_NOFLUSH_SUSPENDING 5 +/* + * Work processed by per-device workqueue. + */ +struct dm_wq_req { + enum { + DM_WQ_FLUSH_ALL, + DM_WQ_FLUSH_DEFERRED, + } type; + struct work_struct work; + struct mapped_device *md; + void *context; +}; + struct mapped_device { struct rw_semaphore io_lock; struct mutex suspend_lock; @@ -96,6 +109,11 @@ struct mapped_device { struct bio_list pushback; /* + * Processing queue (flush/barriers) + */ + struct workqueue_struct *wq; + + /* * The current mapping. */ struct dm_table *map; @@ -1044,6 +1062,10 @@ static struct mapped_device *alloc_dev(int minor) add_disk(md->disk); format_dev_t(md->name, MKDEV(_major, minor)); + md->wq = create_singlethread_workqueue("kdmflush"); + if (!md->wq) + goto bad_thread; + /* Populate the mapping, nobody knows we exist yet */ spin_lock(&_minor_lock); old_md = idr_replace(&_minor_idr, md, minor); @@ -1053,6 +1075,8 @@ static struct mapped_device *alloc_dev(int minor) return md; +bad_thread: + put_disk(md->disk); bad_disk: bioset_free(md->bs); bad_no_bioset: @@ -1080,6 +1104,7 @@ static void free_dev(struct mapped_device *md) unlock_fs(md); bdput(md->suspended_bdev); } + destroy_workqueue(md->wq); mempool_destroy(md->tio_pool); mempool_destroy(md->io_pool); bioset_free(md->bs); @@ -1308,6 +1333,44 @@ static void __merge_pushback_list(struct mapped_device *md) spin_unlock_irqrestore(&md->pushback_lock, flags); } +static void dm_wq_work(struct work_struct *work) +{ + struct dm_wq_req *req = container_of(work, struct dm_wq_req, work); + struct mapped_device *md = req->md; + + down_write(&md->io_lock); + switch (req->type) { + case DM_WQ_FLUSH_ALL: + __merge_pushback_list(md); + /* pass through */ + case DM_WQ_FLUSH_DEFERRED: + __flush_deferred_io(md); + break; + default: + DMERR("dm_wq_work: unrecognised work type %d", req->type); + BUG(); + } + up_write(&md->io_lock); +} + +static void dm_wq_queue(struct mapped_device *md, int type, void *context, + struct dm_wq_req *req) +{ + req->type = type; + req->md = md; + req->context = context; + INIT_WORK(&req->work, dm_wq_work); + queue_work(md->wq, &req->work); +} + +static void dm_queue_flush(struct mapped_device *md, int type, void *context) +{ + struct dm_wq_req req; + + dm_wq_queue(md, type, context, &req); + flush_workqueue(md->wq); +} + /* * Swap in a new table (destroying old one). */ @@ -1450,9 +1513,7 @@ int dm_suspend(struct mapped_device *md, unsigned suspend_flags) /* were we interrupted ? */ if (r < 0) { - down_write(&md->io_lock); - __flush_deferred_io(md); - up_write(&md->io_lock); + dm_queue_flush(md, DM_WQ_FLUSH_DEFERRED, NULL); unlock_fs(md); goto out; /* pushback list is already flushed, so skip flush */ @@ -1463,16 +1524,12 @@ int dm_suspend(struct mapped_device *md, unsigned suspend_flags) set_bit(DMF_SUSPENDED, &md->flags); flush_and_out: - if (r && noflush) { + if (r && noflush) /* * Because there may be already I/Os in the pushback list, * flush them before return. */ - down_write(&md->io_lock); - __merge_pushback_list(md); - __flush_deferred_io(md); - up_write(&md->io_lock); - } + dm_queue_flush(md, DM_WQ_FLUSH_ALL, NULL); out: if (r && md->suspended_bdev) { @@ -1504,9 +1561,7 @@ int dm_resume(struct mapped_device *md) if (r) goto out; - down_write(&md->io_lock); - __flush_deferred_io(md); - up_write(&md->io_lock); + dm_queue_flush(md, DM_WQ_FLUSH_DEFERRED, NULL); unlock_fs(md); |