Add Kill blk_attempt_remerge() patch, oops on ide-cd access with CFQ,

fwd from Dave Jones.

diff --git a/queue/kill-blk_attempt_remerge.patch b/queue/kill-blk_attempt_remerge.patch
new file mode 100644 (file)
index 0000000..6e7f682
--- /dev/null
+++ b/queue/kill-blk_attempt_remerge.patch
@@ -0,0 +1,92 @@
+From stable-bounces@linux.kernel.org  Thu Jan 12 19:27:22 2006
+Date: Mon, 9 Jan 2006 11:15:33 -0800
+From: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
+Subject: [BLOCK] Kill blk_attempt_remerge()
+
+From: Jens Axboe <axboe@suse.de>
+
+[BLOCK] Kill blk_attempt_remerge()
+
+It's a broken interface, it's done way too late. And apparently it triggers
+slab problems in recent kernels as well (most likely after the generic dispatch
+code was merged). So kill it, ide-cd is the only user of it.
+
+Signed-off-by: Jens Axboe <axboe@suse.de>
+chrisw: backport to 2.6.15 tree
+Signed-off-by: Chris Wright <chrisw@sous-sol.org>
+---
+
+ block/ll_rw_blk.c      |   24 ------------------------
+ drivers/ide/ide-cd.c   |   10 ----------
+ include/linux/blkdev.h |    1 -
+ 3 files changed, 35 deletions(-)
+
+--- linux-2.6.15.y.orig/block/ll_rw_blk.c
++++ linux-2.6.15.y/block/ll_rw_blk.c
+@@ -2609,30 +2609,6 @@ static inline int attempt_front_merge(re
+       return 0;
+ }
+ 
+-/**
+- * blk_attempt_remerge  - attempt to remerge active head with next request
+- * @q:    The &request_queue_t belonging to the device
+- * @rq:   The head request (usually)
+- *
+- * Description:
+- *    For head-active devices, the queue can easily be unplugged so quickly
+- *    that proper merging is not done on the front request. This may hurt
+- *    performance greatly for some devices. The block layer cannot safely
+- *    do merging on that first request for these queues, but the driver can
+- *    call this function and make it happen any way. Only the driver knows
+- *    when it is safe to do so.
+- **/
+-void blk_attempt_remerge(request_queue_t *q, struct request *rq)
+-{
+-      unsigned long flags;
+-
+-      spin_lock_irqsave(q->queue_lock, flags);
+-      attempt_back_merge(q, rq);
+-      spin_unlock_irqrestore(q->queue_lock, flags);
+-}
+-
+-EXPORT_SYMBOL(blk_attempt_remerge);
+-
+ static int __make_request(request_queue_t *q, struct bio *bio)
+ {
+       struct request *req;
+--- linux-2.6.15.y.orig/drivers/ide/ide-cd.c
++++ linux-2.6.15.y/drivers/ide/ide-cd.c
+@@ -1332,8 +1332,6 @@ static ide_startstop_t cdrom_start_read 
+       if (cdrom_read_from_buffer(drive))
+               return ide_stopped;
+ 
+-      blk_attempt_remerge(drive->queue, rq);
+-
+       /* Clear the local sector buffer. */
+       info->nsectors_buffered = 0;
+ 
+@@ -1874,14 +1872,6 @@ static ide_startstop_t cdrom_start_write
+               return ide_stopped;
+       }
+ 
+-      /*
+-       * for dvd-ram and such media, it's a really big deal to get
+-       * big writes all the time. so scour the queue and attempt to
+-       * remerge requests, often the plugging will not have had time
+-       * to do this properly
+-       */
+-      blk_attempt_remerge(drive->queue, rq);
+-
+       info->nsectors_buffered = 0;
+ 
+       /* use dma, if possible. we don't need to check more, since we
+--- linux-2.6.15.y.orig/include/linux/blkdev.h
++++ linux-2.6.15.y/include/linux/blkdev.h
+@@ -559,7 +559,6 @@ extern void register_disk(struct gendisk
+ extern void generic_make_request(struct bio *bio);
+ extern void blk_put_request(struct request *);
+ extern void blk_end_sync_rq(struct request *rq);
+-extern void blk_attempt_remerge(request_queue_t *, struct request *);
+ extern struct request *blk_get_request(request_queue_t *, int, gfp_t);
+ extern void blk_insert_request(request_queue_t *, struct request *, int, void *);
+ extern void blk_requeue_request(request_queue_t *, struct request *);

diff --git a/queue/series b/queue/series
index dde6a13c4e99b6bd390a0e2ef014f984838c5985..0eb618ba4a0fb49a5adb9055a382f21ebbb0fdf9 100644 (file)
--- a/queue/series
+++ b/queue/series
@@ -1 +1,2 @@
 usb-audio-dont-use-empty-packets-at-start-of-playback.patch
+kill-blk_attempt_remerge.patch