linux/block, branch v2.6.37

Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block

2010-12-20T17:19:46Z

* 'for-linus' of git://git.kernel.dk/linux-2.6-block: cciss: fix cciss_revalidate panic block: max hardware sectors limit wrapper block: Deprecate QUEUE_FLAG_CLUSTER and use queue_limits instead blk-throttle: Correct the placement of smp_rmb() blk-throttle: Trim/adjust slice_end once a bio has been dispatched block: check for proper length of iov entries earlier in blk_rq_map_user_iov() drbd: fix for spin_lock_irqsave in endio callback drbd: don't recvmsg with zero length

block: max hardware sectors limit wrapper

2010-12-17T07:36:01Z

Implement blk_limits_max_hw_sectors() and make blk_queue_max_hw_sectors() a wrapper around it. DM needs this to avoid setting queue_limits' max_hw_sectors and max_sectors directly. dm_set_device_limits() now leverages blk_limits_max_hw_sectors() logic to establish the appropriate max_hw_sectors minimum (PAGE_SIZE). Fixes issue where DM was incorrectly setting max_sectors rather than max_hw_sectors (which caused dm_merge_bvec()'s max_hw_sectors check to be ineffective). Signed-off-by: Mike Snitzer Cc: stable@kernel.org Acked-by: Martin K. Petersen Signed-off-by: Jens Axboe

block: Deprecate QUEUE_FLAG_CLUSTER and use queue_limits instead

2010-12-17T07:35:53Z

When stacking devices, a request_queue is not always available. This forced us to have a no_cluster flag in the queue_limits that could be used as a carrier until the request_queue had been set up for a metadevice. There were several problems with that approach. First of all it was up to the stacking device to remember to set queue flag after stacking had completed. Also, the queue flag and the queue limits had to be kept in sync at all times. We got that wrong, which could lead to us issuing commands that went beyond the max scatterlist limit set by the driver. The proper fix is to avoid having two flags for tracking the same thing. We deprecate QUEUE_FLAG_CLUSTER and use the queue limit directly in the block layer merging functions. The queue_limit 'no_cluster' is turned into 'cluster' to avoid double negatives and to ease stacking. Clustering defaults to being enabled as before. The queue flag logic is removed from the stacking function, and explicitly setting the cluster flag is no longer necessary in DM and MD. Reported-by: Ed Lin Signed-off-by: Martin K. Petersen Acked-by: Mike Snitzer Cc: stable@kernel.org Signed-off-by: Jens Axboe

[SCSI] bsg: correct fault if queue object removed while dev_t open

2010-12-09T15:41:14Z

This patch corrects an issue in bsg that results in a general protection fault if an LLD is removed while an application is using an open file handle to a bsg device, and the application issues an ioctl. The fault occurs because the class_dev is NULL, having been cleared in bsg_unregister_queue() when the driver was removed. With this patch, a check is made for the class_dev, and the application will receive ENXIO if the related object is gone. Signed-off-by: Carl Lajeunesse Signed-off-by: James Smart Signed-off-by: James Bottomley

blk-throttle: Correct the placement of smp_rmb()

2010-12-01T18:34:52Z

o I was discussing what are the variable being updated without spin lock and why do we need barriers and Oleg pointed out that location of smp_rmb() should be between read of td->limits_changed and tg->limits_changed. This patch fixes it. o Following is one possible sequence of events. Say cpu0 is executing throtl_update_blkio_group_read_bps() and cpu1 is executing throtl_process_limit_change(). cpu0 cpu1 tg->limits_changed = true; smp_mb__before_atomic_inc(); atomic_inc(&td->limits_changed); if (!atomic_read(&td->limits_changed)) return; if (tg->limits_changed) do_something; If cpu0 has updated tg->limits_changed and td->limits_changed, we want to make sure that if update to td->limits_changed is visible on cpu1, then update to tg->limits_changed should also be visible. Oleg pointed out to ensure that we need to insert an smp_rmb() between td->limits_changed read and tg->limits_changed read. o I had erroneously put smp_rmb() before atomic_read(&td->limits_changed). This patch fixes it. Reported-by: Oleg Nesterov Signed-off-by: Vivek Goyal Signed-off-by: Jens Axboe

blk-throttle: Trim/adjust slice_end once a bio has been dispatched

2010-12-01T18:34:46Z

o During some testing I did following and noticed throttling stops working. - Put a very low limit on a cgroup, say 1 byte per second. - Start some reads, this will set slice_end to a very high value. - Change the limit to higher value say 1MB/s - Now IO unthrottles and finishes as expected. - Try to do the read again but IO is not limited to 1MB/s as expected. o What is happening. - Initially low value of limit sets slice_end to a very high value. - During updation of limit, slice_end is not being truncated. - Very high value of slice_end leads to keeping the existing slice valid for a very long time and new slice does not start. - tg_may_dispatch() is called in blk_throtle_bio(), and trim_slice() is not called in this path. So slice_start is some old value and practically we are able to do huge amount of IO. o There are many ways it can be fixed. I have fixed it by trying to adjust/cleanup slice_end in trim_slice(). Generally we extend slices if bio is big and can't be dispatched in one slice. After dispatch of bio, readjust the slice_end to make sure we don't end up with huge values. Signed-off-by: Vivek Goyal Signed-off-by: Jens Axboe

block: check for proper length of iov entries earlier in blk_rq_map_user_iov()

2010-11-29T09:04:50Z

commit 9284bcf checks for proper length of iov entries in blk_rq_map_user_iov(). But if the map is unaligned, kernel will break out the loop without checking for the proper length. So we need to check the proper length before the unalign check. Signed-off-by: Xiaotian Feng Cc: stable@kernel.org Signed-off-by: Jens Axboe

Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block

2010-11-26T22:17:50Z

* 'for-linus' of git://git.kernel.dk/linux-2.6-block: cciss: fix build for PROC_FS disabled block: fix amiga and atari floppy driver compile warning blk-throttle: Fix calculation of max number of WRITES to be dispatched ioprio: grab rcu_read_lock in sys_ioprio_{set,get}() xen/blkfront: cope with backend that fail empty BLKIF_OP_WRITE_BARRIER requests xen/blkfront: Implement FUA with BLKIF_OP_WRITE_BARRIER xen/blkfront: change blk_shadow.request to proper pointer xen/blkfront: map REQ_FLUSH into a full barrier

BKL: remove extraneous #include

2010-11-17T16:59:32Z

The big kernel lock has been removed from all these files at some point, leaving only the #include. Remove this too as a cleanup. Signed-off-by: Arnd Bergmann Signed-off-by: Linus Torvalds

blk-throttle: Fix calculation of max number of WRITES to be dispatched

2010-11-15T18:32:42Z

o Currently we try to dispatch more READS and less WRITES (75%, 25%) in one dispatch round. ummy pointed out that there is a bug in max_nr_writes calculation. This patch fixes it. Reported-by: ummy y Signed-off-by: Vivek Goyal Signed-off-by: Jens Axboe