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authorLinus Torvalds <torvalds@linux-foundation.org>2015-02-12 14:30:53 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2015-02-12 14:30:53 -0800
commit8494bcf5b7c4b2416687e233dd34d4c6b6fe5653 (patch)
treecebb468e170e639ecfd61ddc5ebcba86c21105fa /block
parent3e12cefbe143b4947171ff92dd50024c4841e291 (diff)
parentb042a3ca949053231950a1b15f31cccca9e305f3 (diff)
downloadlwn-8494bcf5b7c4b2416687e233dd34d4c6b6fe5653.tar.gz
lwn-8494bcf5b7c4b2416687e233dd34d4c6b6fe5653.zip
Merge branch 'for-3.20/drivers' of git://git.kernel.dk/linux-block
Pull block driver changes from Jens Axboe: "This contains: - The 4k/partition fixes for brd from Boaz/Matthew. - A few xen front/back block fixes from David Vrabel and Roger Pau Monne. - Floppy changes from Takashi, cleaning the device file creation. - Switching libata to use the new blk-mq tagging policy, removing code (and a suboptimal implementation) from libata. This will throw you a merge conflict, since a bug in the original libata tagging code was fixed since this code was branched. Trivial. From Shaohua. - Conversion of loop to blk-mq, from Ming Lei. - Cleanup of the io_schedule() handling in bsg from Peter Zijlstra. He claims it improves on unreadable code, which will cost him a beer. - Maintainer update or NDB, now handled by Markus Pargmann. - NVMe: - Optimization from me that avoids a kmalloc/kfree per IO for smaller (<= 8KB) IO. This cuts about 1% of high IOPS CPU overhead. - Removal of (now) dead RCU code, a relic from before NVMe was converted to blk-mq" * 'for-3.20/drivers' of git://git.kernel.dk/linux-block: xen-blkback: default to X86_32 ABI on x86 xen-blkfront: fix accounting of reqs when migrating xen-blkback,xen-blkfront: add myself as maintainer block: Simplify bsg complete all floppy: Avoid manual call of device_create_file() NVMe: avoid kmalloc/kfree for smaller IO MAINTAINERS: Update NBD maintainer libata: make sata_sil24 use fifo tag allocator libata: move sas ata tag allocation to libata-scsi.c libata: use blk taging NVMe: within nvme_free_queues(), delete RCU sychro/deferred free null_blk: suppress invalid partition info brd: Request from fdisk 4k alignment brd: Fix all partitions BUGs axonram: Fix bug in direct_access loop: add blk-mq.h include block: loop: don't handle REQ_FUA explicitly block: loop: introduce lo_discard() and lo_req_flush() block: loop: say goodby to bio block: loop: improve performance via blk-mq
Diffstat (limited to 'block')
-rw-r--r--block/bsg.c72
1 files changed, 25 insertions, 47 deletions
diff --git a/block/bsg.c b/block/bsg.c
index 276e869e686c..d214e929ce18 100644
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -136,42 +136,6 @@ static inline struct hlist_head *bsg_dev_idx_hash(int index)
return &bsg_device_list[index & (BSG_LIST_ARRAY_SIZE - 1)];
}
-static int bsg_io_schedule(struct bsg_device *bd)
-{
- DEFINE_WAIT(wait);
- int ret = 0;
-
- spin_lock_irq(&bd->lock);
-
- BUG_ON(bd->done_cmds > bd->queued_cmds);
-
- /*
- * -ENOSPC or -ENODATA? I'm going for -ENODATA, meaning "I have no
- * work to do", even though we return -ENOSPC after this same test
- * during bsg_write() -- there, it means our buffer can't have more
- * bsg_commands added to it, thus has no space left.
- */
- if (bd->done_cmds == bd->queued_cmds) {
- ret = -ENODATA;
- goto unlock;
- }
-
- if (!test_bit(BSG_F_BLOCK, &bd->flags)) {
- ret = -EAGAIN;
- goto unlock;
- }
-
- prepare_to_wait(&bd->wq_done, &wait, TASK_UNINTERRUPTIBLE);
- spin_unlock_irq(&bd->lock);
- io_schedule();
- finish_wait(&bd->wq_done, &wait);
-
- return ret;
-unlock:
- spin_unlock_irq(&bd->lock);
- return ret;
-}
-
static int blk_fill_sgv4_hdr_rq(struct request_queue *q, struct request *rq,
struct sg_io_v4 *hdr, struct bsg_device *bd,
fmode_t has_write_perm)
@@ -482,6 +446,30 @@ static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr,
return ret;
}
+static bool bsg_complete(struct bsg_device *bd)
+{
+ bool ret = false;
+ bool spin;
+
+ do {
+ spin_lock_irq(&bd->lock);
+
+ BUG_ON(bd->done_cmds > bd->queued_cmds);
+
+ /*
+ * All commands consumed.
+ */
+ if (bd->done_cmds == bd->queued_cmds)
+ ret = true;
+
+ spin = !test_bit(BSG_F_BLOCK, &bd->flags);
+
+ spin_unlock_irq(&bd->lock);
+ } while (!ret && spin);
+
+ return ret;
+}
+
static int bsg_complete_all_commands(struct bsg_device *bd)
{
struct bsg_command *bc;
@@ -492,17 +480,7 @@ static int bsg_complete_all_commands(struct bsg_device *bd)
/*
* wait for all commands to complete
*/
- ret = 0;
- do {
- ret = bsg_io_schedule(bd);
- /*
- * look for -ENODATA specifically -- we'll sometimes get
- * -ERESTARTSYS when we've taken a signal, but we can't
- * return until we're done freeing the queue, so ignore
- * it. The signal will get handled when we're done freeing
- * the bsg_device.
- */
- } while (ret != -ENODATA);
+ io_wait_event(bd->wq_done, bsg_complete(bd));
/*
* discard done commands