lkml.org 
[lkml]   [2004]   [Aug]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Subject[PATCH 1/3] blk_queue_free_tags
From
Date

This is a resend of three ll_rw_blk patches related to tagged queuing.

Currently blk_queue_free_tags cannot be called with ops outstanding. The
scsi_tcq API defined to LLD scsi drivers allows for scsi_deactivate_tcq
to be called (which calls blk_queue_free_tags) with ops outstanding. Change
blk_queue_free_tags to no longer free the tags, but rather just disable
tagged queuing and also modify blk_queue_init_tags to handle re-enabling
tagged queuing after it has been disabled.

Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Brian King <brking@us.ibm.com>
---

linux-2.6.8-rc3-mm2-bjking1/drivers/block/ll_rw_blk.c | 35 ++++++++++++++----
1 files changed, 28 insertions(+), 7 deletions(-)

diff -puN drivers/block/ll_rw_blk.c~blk_queue_free_tags drivers/block/ll_rw_blk.c
--- linux-2.6.8-rc3-mm2/drivers/block/ll_rw_blk.c~blk_queue_free_tags 2004-08-09 14:10:50.000000000 -0500
+++ linux-2.6.8-rc3-mm2-bjking1/drivers/block/ll_rw_blk.c 2004-08-09 14:48:18.000000000 -0500
@@ -521,15 +521,14 @@ struct request *blk_queue_find_tag(reque
EXPORT_SYMBOL(blk_queue_find_tag);

/**
- * blk_queue_free_tags - release tag maintenance info
+ * __blk_queue_free_tags - release tag maintenance info
* @q: the request queue for the device
*
* Notes:
* blk_cleanup_queue() will take care of calling this function, if tagging
- * has been used. So there's usually no need to call this directly, unless
- * tagging is just being disabled but the queue remains in function.
+ * has been used. So there's no need to call this directly.
**/
-void blk_queue_free_tags(request_queue_t *q)
+static void __blk_queue_free_tags(request_queue_t *q)
{
struct blk_queue_tag *bqt = q->queue_tags;

@@ -553,6 +552,19 @@ void blk_queue_free_tags(request_queue_t
q->queue_flags &= ~(1 << QUEUE_FLAG_QUEUED);
}

+/**
+ * blk_queue_free_tags - release tag maintenance info
+ * @q: the request queue for the device
+ *
+ * Notes:
+ * This is used to disabled tagged queuing to a device, yet leave
+ * queue in function.
+ **/
+void blk_queue_free_tags(request_queue_t *q)
+{
+ clear_bit(QUEUE_FLAG_QUEUED, &q->queue_flags);
+}
+
EXPORT_SYMBOL(blk_queue_free_tags);

static int
@@ -603,13 +615,22 @@ fail:
int blk_queue_init_tags(request_queue_t *q, int depth,
struct blk_queue_tag *tags)
{
- if (!tags) {
+ int rc;
+
+ BUG_ON(tags && q->queue_tags && tags != q->queue_tags);
+
+ if (!tags && !q->queue_tags) {
tags = kmalloc(sizeof(struct blk_queue_tag), GFP_ATOMIC);
if (!tags)
goto fail;

if (init_tag_map(q, tags, depth))
goto fail;
+ } else if (q->queue_tags) {
+ if ((rc = blk_queue_resize_tags(q, depth)))
+ return rc;
+ set_bit(QUEUE_FLAG_QUEUED, &q->queue_flags);
+ return 0;
} else
atomic_inc(&tags->refcnt);

@@ -1373,8 +1394,8 @@ void blk_cleanup_queue(request_queue_t *
if (rl->rq_pool)
mempool_destroy(rl->rq_pool);

- if (blk_queue_tagged(q))
- blk_queue_free_tags(q);
+ if (q->queue_tags)
+ __blk_queue_free_tags(q);

kmem_cache_free(requestq_cachep, q);
}
_
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
\
 
 \ /
  Last update: 2005-03-22 14:05    [W:0.022 / U:23.564 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site