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authorChristoph Hellwig <hch@lst.de>2014-01-22 15:29:29 +0100
committerChristoph Hellwig <hch@lst.de>2014-07-25 07:43:43 -0400
commit74665016086615bbaa3fa6f83af410a0a4e029ee (patch)
tree9f9d8a692bec91dce69fd303eeedf16c35b41ac6 /drivers/scsi/libiscsi.c
parent7ae65c0f9646c29432b69580b80e08632e6cd813 (diff)
downloadlinux-74665016086615bbaa3fa6f83af410a0a4e029ee.tar.bz2
scsi: convert host_busy to atomic_t
Avoid taking the host-wide host_lock to check the per-host queue limit. Instead we do an atomic_inc_return early on to grab our slot in the queue, and if necessary decrement it after finishing all checks. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Webb Scales <webbnh@hp.com> Acked-by: Jens Axboe <axboe@kernel.dk> Tested-by: Bart Van Assche <bvanassche@acm.org> Tested-by: Robert Elliott <elliott@hp.com>
Diffstat (limited to 'drivers/scsi/libiscsi.c')
-rw-r--r--drivers/scsi/libiscsi.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index f2db82beb646..f9f3a1224dfa 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -2971,7 +2971,7 @@ void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
*/
for (;;) {
spin_lock_irqsave(session->host->host_lock, flags);
- if (!session->host->host_busy) { /* OK for ERL == 0 */
+ if (!atomic_read(&session->host->host_busy)) { /* OK for ERL == 0 */
spin_unlock_irqrestore(session->host->host_lock, flags);
break;
}
@@ -2979,7 +2979,7 @@ void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
msleep_interruptible(500);
iscsi_conn_printk(KERN_INFO, conn, "iscsi conn_destroy(): "
"host_busy %d host_failed %d\n",
- session->host->host_busy,
+ atomic_read(&session->host->host_busy),
session->host->host_failed);
/*
* force eh_abort() to unblock