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2012-01-19Merge commit 'v2.6.35.14' into del-5.8/mainAlex Gonzalez
Conflicts: arch/arm/plat-mxc/include/mach/gpio.h arch/x86/kernel/cpu/mtrr/main.c drivers/mmc/core/core.c drivers/net/smsc911x.c fs/proc/task_mmu.c include/linux/pm_runtime.h mm/memory.c mm/mlock.c Signed-off-by: Alex Gonzalez <alex.gonzalez@digi.com>
2011-08-01fix crash in scsi_dispatch_cmd()James Bottomley
[ upstream commit bfe159a51203c15d23cb3158fffdc25ec4b4dda1 ] USB surprise removal of sr is triggering an oops in scsi_dispatch_command(). What seems to be happening is that USB is hanging on to a queue reference until the last close of the upper device, so the crash is caused by surprise remove of a mounted CD followed by attempted unmount. The problem is that USB doesn't issue its final commands as part of the SCSI teardown path, but on last close when the block queue is long gone. The long term fix is probably to make sr do the teardown in the same way as sd (so remove all the lower bits on ejection, but keep the upper disk alive until last close of user space). However, the current oops can be simply fixed by not allowing any commands to be sent to a dead queue. Cc: stable@kernel.org Signed-off-by: James Bottomley <JBottomley@Parallels.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2011-08-01cfq-iosched: fix a rcu warningShaohua Li
commit 3181faa85bda3dc3f5e630a1846526c9caaa38e3 upstream. I got a rcu warnning at boot. the ioc->ioc_data is rcu_deferenced, but doesn't hold rcu_read_lock. Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2011-08-01cfq-iosched: fix locking around ioc->ioc_data assignmentJens Axboe
commit ab4bd22d3cce6977dc039664cc2d052e3147d662 upstream. Since we are modifying this RCU pointer, we need to hold the lock protecting it around it. This fixes a potential reuse and double free of a cfq io_context structure. The bug has been in CFQ for a long time, it hit very few people but those it did hit seemed to see it a lot. Tracked in RH bugzilla here: https://bugzilla.redhat.com/show_bug.cgi?id=577968 Credit goes to Paul Bolle for figuring out that the issue was around the one-hit ioc->ioc_data cache. Thanks to his hard work the issue is now fixed. Signed-off-by: Jens Axboe <jaxboe@fusionio.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2011-08-01block: export blk_{get,put}_queue()Jens Axboe
commit d86e0e83b32bc84600adb0b6ea1fce389b266682 upstream. We need them in SCSI to fix a bug, but currently they are not exported to modules. Export them. Signed-off-by: Jens Axboe <jaxboe@fusionio.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2011-08-01block: add proper state guards to __elv_next_requestJames Bottomley
commit 0a58e077eb600d1efd7e54ad9926a75a39d7f8ae upstream. blk_cleanup_queue() calls elevator_exit() and after this, we can't touch the elevator without oopsing. __elv_next_request() must check for this state because in the refcounted queue model, we can still call it after blk_cleanup_queue() has been called. This was reported as causing an oops attributable to scsi. Signed-off-by: James Bottomley <James.Bottomley@suse.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2011-04-28block, blk-sysfs: Fix an err return path in blk_register_queue()Liu Yuan
commit ed5302d3c25006a9edc7a7fbea97a30483f89ef7 upstream. We do not call blk_trace_remove_sysfs() in err return path if kobject_add() fails. This path fixes it. Signed-off-by: Liu Yuan <tailai.ly@taobao.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2011-02-06block: Deprecate QUEUE_FLAG_CLUSTER and use queue_limits insteadMartin K. Petersen
commit e692cb668fdd5a712c6ed2a2d6f2a36ee83997b4 upstream. 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 <ed.lin@promise.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2011-01-17Android block: genhd: Add disk/partition specific uevent callbacks for ↵San Mehat
partition info For disk devices, a new uevent parameter 'NPARTS' specifies the number of partitions detected by the kernel. Partition devices get 'PARTN' which specifies the partitions index in the table. Signed-off-by: San Mehat <san@google.com>
2010-12-14block: check for proper length of iov entries in blk_rq_map_user_iov()Jens Axboe
commit 9284bcf4e335e5f18a8bc7b26461c33ab60d0689 upstream. Ensure that we pass down properly validated iov segments before calling into the mapping or copy functions. Reported-by: Dan Rosenberg <drosenberg@vsecurity.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2010-12-14block: take care not to overflow when calculating total iov lengthJens Axboe
commit 9f864c80913467312c7b8690e41fb5ebd1b50e92 upstream. Reported-by: Dan Rosenberg <drosenberg@vsecurity.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2010-12-14block: Fix race during disk initializationJan Kara
commit 01ea50638bc04ca5259f5711fcdedefcdde1cf43 upstream. When a new disk is being discovered, add_disk() first ties the bdev to gendisk (via register_disk()->blkdev_get()) and only after that calls bdi_register_bdev(). Because register_disk() also creates disk's kobject, it can happen that userspace manages to open and modify the device's data (or inode) before its BDI is properly initialized leading to a warning in __mark_inode_dirty(). Fix the problem by registering BDI early enough. This patch addresses https://bugzilla.kernel.org/show_bug.cgi?id=16312 Reported-by: Larry Finger <Larry.Finger@lwfinger.net> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <jaxboe@fusionio.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2010-12-14block: Ensure physical block size is unsigned intMartin K. Petersen
commit 892b6f90db81cccb723d5d92f4fddc2d68b206e1 upstream. Physical block size was declared unsigned int to accomodate the maximum size reported by READ CAPACITY(16). Make sure we use the right type in the related functions. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2010-10-28bsg: fix incorrect device_status valueFUJITA Tomonori
commit 478971600e47cb83ff2d3c63c5c24f2b04b0d6a1 upstream. bsg incorrectly returns sg's masked_status value for device_status. [jejb: fix up expression logic] Reported-by: Douglas Gilbert <dgilbert@interlog.com> Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: James Bottomley <James.Bottomley@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-06-24block: Don't count_vm_events for discard bio in submit_bio.Tao Ma
In submit_bio, we count vm events by check READ/WRITE. But actually DISCARD_NOBARRIER also has the WRITE flag set. It looks as if in blkdev_issue_discard, we also add a page as the payload and the bio_has_data check isn't enough. So add another check for discard bio. Signed-off-by: Tao Ma <tao.ma@oracle.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-06-21cfq: fix recursive call in cfq_blkiocg_update_completion_stats()Jens Axboe
e98ef89b has a typo, causing cfq_blkiocg_update_completion_stats() to call itself instead of blkiocg_update_completion_stats(). Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-06-18cfq-iosched: Fixed boot warning with BLK_CGROUP=y and CFQ_GROUP_IOSCHED=nVivek Goyal
Hi Jens, Few days back Ingo noticed a CFQ boot time warning. This patch fixes it. The issue here is that with CFQ_GROUP_IOSCHED=n, CFQ should not really be making blkio stat related calls. > Hm, it's still not entirely fixed, as of 2.6.35-rc2-00131-g7908a9e. With > some > configs i get bad spinlock warnings during bootup: > > [ 28.968013] initcall net_olddevs_init+0x0/0x82 returned 0 after 93750 > usecs > [ 28.972003] calling b44_init+0x0/0x55 @ 1 > [ 28.976009] bus: 'pci': add driver b44 > [ 28.976374] sda: > [ 28.978157] BUG: spinlock bad magic on CPU#1, async/0/117 > [ 28.980000] lock: 7e1c5bbc, .magic: 00000000, .owner: <none>/-1, +.owner_cpu: 0 > [ 28.980000] Pid: 117, comm: async/0 Not tainted +2.6.35-rc2-tip-01092-g010e7ef-dirty #8183 > [ 28.980000] Call Trace: > [ 28.980000] [<41ba6d55>] ? printk+0x20/0x24 > [ 28.980000] [<4134b7b7>] spin_bug+0x7c/0x87 > [ 28.980000] [<4134b853>] do_raw_spin_lock+0x1e/0x123 > [ 28.980000] [<41ba92ca>] ? _raw_spin_lock_irqsave+0x12/0x20 > [ 28.980000] [<41ba92d2>] _raw_spin_lock_irqsave+0x1a/0x20 > [ 28.980000] [<4133476f>] blkiocg_update_io_add_stats+0x25/0xfb > [ 28.980000] [<41335dae>] ? cfq_prio_tree_add+0xb1/0xc1 > [ 28.980000] [<41337bc7>] cfq_insert_request+0x8c/0x425 Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-06-17cfq: Don't allow queue merges for queues that have no process referencesJeff Moyer
Hi, A user reported a kernel bug when running a particular program that did the following: created 32 threads - each thread took a mutex, grabbed a global offset, added a buffer size to that offset, released the lock - read from the given offset in the file - created a new thread to do the same - exited The result is that cfq's close cooperator logic would trigger, as the threads were issuing I/O within the mean seek distance of one another. This workload managed to routinely trigger a use after free bug when walking the list of merge candidates for a particular cfqq (cfqq->new_cfqq). The logic used for merging queues looks like this: static void cfq_setup_merge(struct cfq_queue *cfqq, struct cfq_queue *new_cfqq) { int process_refs, new_process_refs; struct cfq_queue *__cfqq; /* Avoid a circular list and skip interim queue merges */ while ((__cfqq = new_cfqq->new_cfqq)) { if (__cfqq == cfqq) return; new_cfqq = __cfqq; } process_refs = cfqq_process_refs(cfqq); /* * If the process for the cfqq has gone away, there is no * sense in merging the queues. */ if (process_refs == 0) return; /* * Merge in the direction of the lesser amount of work. */ new_process_refs = cfqq_process_refs(new_cfqq); if (new_process_refs >= process_refs) { cfqq->new_cfqq = new_cfqq; atomic_add(process_refs, &new_cfqq->ref); } else { new_cfqq->new_cfqq = cfqq; atomic_add(new_process_refs, &cfqq->ref); } } When a merge candidate is found, we add the process references for the queue with less references to the queue with more. The actual merging of queues happens when a new request is issued for a given cfqq. In the case of the test program, it only does a single pread call to read in 1MB, so the actual merge never happens. Normally, this is fine, as when the queue exits, we simply drop the references we took on the other cfqqs in the merge chain: /* * If this queue was scheduled to merge with another queue, be * sure to drop the reference taken on that queue (and others in * the merge chain). See cfq_setup_merge and cfq_merge_cfqqs. */ __cfqq = cfqq->new_cfqq; while (__cfqq) { if (__cfqq == cfqq) { WARN(1, "cfqq->new_cfqq loop detected\n"); break; } next = __cfqq->new_cfqq; cfq_put_queue(__cfqq); __cfqq = next; } However, there is a hole in this logic. Consider the following (and keep in mind that each I/O keeps a reference to the cfqq): q1->new_cfqq = q2 // q2 now has 2 process references q3->new_cfqq = q2 // q2 now has 3 process references // the process associated with q2 exits // q2 now has 2 process references // queue 1 exits, drops its reference on q2 // q2 now has 1 process reference // q3 exits, so has 0 process references, and hence drops its references // to q2, which leaves q2 also with 0 process references q4 comes along and wants to merge with q3 q3->new_cfqq still points at q2! We follow that link and end up at an already freed cfqq. So, the fix is to not follow a merge chain if the top-most queue does not have a process reference, otherwise any queue in the chain could be already freed. I also changed the logic to disallow merging with a queue that does not have any process references. Previously, we did this check for one of the merge candidates, but not the other. That doesn't really make sense. Without the attached patch, my system would BUG within a couple of seconds of running the reproducer program. With the patch applied, my system ran the program for over an hour without issues. This addresses the following bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=16217 Thanks a ton to Phil Carns for providing the bug report and an excellent reproducer. [ Note for stable: this applies to 2.6.32/33/34 ]. Signed-off-by: Jeff Moyer <jmoyer@redhat.com> Reported-by: Phil Carns <carns@mcs.anl.gov> Cc: stable@kernel.org Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-06-17block: fix DISCARD_BARRIER requestsChristoph Hellwig
Filesystems assume that DISCARD_BARRIER are full barriers, so that they don't have to track in-progress discard operation when submitting new I/O. But currently we only treat them as elevator barriers, which don't actually do the nessecary queue drains. Also remove the unlikely around both the DISCARD and BARRIER requests - the happen far too often for a static mispredict. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-06-04block: make blk_init_free_list and elevator_init idempotentMike Snitzer
blk_init_allocated_queue_node may fail and the caller _could_ retry. Accommodate the unlikely event that blk_init_allocated_queue_node is called on an already initialized (possibly partially) request_queue. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-06-04block: avoid unconditionally freeing previously allocated request_queueMike Snitzer
On blk_init_allocated_queue_node failure, only free the request_queue if it is wasn't previously allocated outside the block layer (e.g. blk_init_queue_node was blk_init_allocated_queue_node caller). This addresses an interface bug introduced by the following commit: 01effb0 block: allow initialization of previously allocated request_queue Otherwise the request_queue may be free'd out from underneath a caller that is managing the request_queue directly (e.g. caller uses blk_alloc_queue + blk_init_allocated_queue_node). Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-05-25cfq-iosched: fix an oops caused by slab leakShaohua Li
I got below oops when unloading cfq-iosched. Considering scenario: queue A merge to B, C merge to D and B will be merged to D. Before B is merged to D, we do split B. We should put B's reference for D. [ 807.768536] ============================================================================= [ 807.768539] BUG cfq_queue: Objects remaining on kmem_cache_close() [ 807.768541] ----------------------------------------------------------------------------- [ 807.768543] [ 807.768546] INFO: Slab 0xffffea0003e6b4e0 objects=26 used=1 fp=0xffff88011d584fd8 flags=0x200000000004082 [ 807.768550] Pid: 5946, comm: rmmod Tainted: G W 2.6.34-07097-gf4b87de-dirty #724 [ 807.768552] Call Trace: [ 807.768560] [<ffffffff81104e8d>] slab_err+0x8f/0x9d [ 807.768564] [<ffffffff811059e1>] ? flush_cpu_slab+0x0/0x93 [ 807.768569] [<ffffffff8164be52>] ? add_preempt_count+0xe/0xca [ 807.768572] [<ffffffff8164bd9c>] ? sub_preempt_count+0xe/0xb6 [ 807.768577] [<ffffffff81648871>] ? _raw_spin_unlock+0x15/0x30 [ 807.768580] [<ffffffff8164bd9c>] ? sub_preempt_count+0xe/0xb6 [ 807.768584] [<ffffffff811061bc>] list_slab_objects+0x9b/0x19f [ 807.768588] [<ffffffff8164bf0a>] ? add_preempt_count+0xc6/0xca [ 807.768591] [<ffffffff81109e27>] kmem_cache_destroy+0x13f/0x21d [ 807.768597] [<ffffffffa000ff13>] cfq_slab_kill+0x1a/0x43 [cfq_iosched] [ 807.768601] [<ffffffffa000ffcf>] cfq_exit+0x93/0x9e [cfq_iosched] [ 807.768606] [<ffffffff810973a2>] sys_delete_module+0x1b1/0x219 [ 807.768612] [<ffffffff8102fb5b>] system_call_fastpath+0x16/0x1b [ 807.768618] INFO: Object 0xffff88011d584618 @offset=1560 [ 807.768622] INFO: Allocated in cfq_get_queue+0x11e/0x274 [cfq_iosched] age=7173 cpu=1 pid=5496 [ 807.768626] ============================================================================= Cc: stable@kernel.org Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-24block: Adjust elv_iosched_show to return "none" for bio-based DMMike Snitzer
Bio-based DM doesn't use an elevator (queue is !blk_queue_stackable()). Longer-term DM will not allocate an elevator for bio-based DM. But even then there will be small potential for an elevator to be allocated for a request-based DM table only to have a bio-based table be loaded in the end. Displaying "none" for bio-based DM will help avoid user confusion. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-24cfq-iosched: compact io_context radix_treeKonstantin Khlebnikov
Use small consequent indexes as radix tree keys instead of sparse cfqd address. This change will reduce radix tree depth from 11 (6 for 32-bit hosts) to 1 if host have <=64 disks under cfq control, or to 0 if there only one disk. So, this patch save 10*560 bytes for each process (5*296 for 32-bit hosts) For each cfqd allocate cic index from ida. To unlink dead cic from tree without cfqd access store index into ->key. (bit 0 -- dead mark, bits 1..30 -- index: ida produce id in range 0..2^31-1) Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-24cfq-iosched: remove dead_key from cfq_io_contextKonstantin Khlebnikov
Remove ->dead_key field from cfq_io_context to shrink its size to 128 bytes. (64 bytes for 32-bit hosts) Use lower bit in ->key as dead-mark, instead of moving key to separate field. After this for dead cfq_io_context we got cic->key != cfqd automatically. Thus, io_context's last-hit cache should work without changing. Now to check ->key for non-dead state compare it with cfqd, instead of checking ->key for non-null value as it was before. Plus remove obsolete race protection in cfq_cic_lookup. This race gone after v2.6.24-1728-g4ac845a Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-21Merge branch 'master' into for-2.6.35Jens Axboe
Conflicts: fs/ext3/fsync.c Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-21block: remove all rcu head initializationsPaul E. McKenney
Remove all rcu head inits. We don't care about the RCU head state before passing it to call_rcu() anyway. Only leave the "on_stack" variants so debugobjects can keep track of objects on stack. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-11block: allow initialization of previously allocated request_queueMike Snitzer
blk_init_queue() allocates the request_queue structure and then initializes it as needed (request_fn, elevator, etc). Split initialization out to blk_init_allocated_queue_node. Introduce blk_init_allocated_queue wrapper function to model existing blk_init_queue and blk_init_queue_node interfaces. Export elv_register_queue to allow a newly added elevator to be registered with sysfs. Export elv_unregister_queue for symmetry. These changes allow DM to initialize a device's request_queue with more precision. In particular, DM no longer unconditionally initializes a full request_queue (elevator et al). It only does so for a request-based DM device. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-07blk-cgroup: Fix an RCU warning in blkiocg_create()Li Zefan
with CONFIG_PROVE_RCU=y, a warning can be triggered: # mount -t cgroup -o blkio xxx /mnt # mkdir /mnt/subgroup ... kernel/cgroup.c:4442 invoked rcu_dereference_check() without protection! ... To fix this, we avoid caling css_depth() here, which is a bit simpler than the original code. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-06blk-cgroup: Fix RCU correctness warning in cfq_init_queue()Vivek Goyal
It is necessary to be in an RCU read-side critical section when invoking css_id(), so this patch adds one to blkiocg_add_blkio_group(). This is actually a false positive, because this is called at initialization time and hence always refers to the root cgroup, which cannot go away. [ 103.790505] =================================================== [ 103.790509] [ INFO: suspicious rcu_dereference_check() usage. ] [ 103.790511] --------------------------------------------------- [ 103.790514] kernel/cgroup.c:4432 invoked rcu_dereference_check() without protection! [ 103.790517] [ 103.790517] other info that might help us debug this: [ 103.790519] [ 103.790521] [ 103.790521] rcu_scheduler_active = 1, debug_locks = 1 [ 103.790524] 4 locks held by bash/4422: [ 103.790526] #0: (&buffer->mutex){+.+.+.}, at: [<ffffffff8114befa>] sysfs_write_file+0x3c/0x144 [ 103.790537] #1: (s_active#102){.+.+.+}, at: [<ffffffff8114bfa5>] sysfs_write_file+0xe7/0x144 [ 103.790544] #2: (&q->sysfs_lock){+.+.+.}, at: [<ffffffff812263b1>] queue_attr_store+0x49/0x8f [ 103.790552] #3: (&(&blkcg->lock)->rlock){......}, at: [<ffffffff8122e4db>] blkiocg_add_blkio_group+0x2b/0xad [ 103.790560] [ 103.790561] stack backtrace: [ 103.790564] Pid: 4422, comm: bash Not tainted 2.6.34-rc4-blkio-second-crash #81 [ 103.790567] Call Trace: [ 103.790572] [<ffffffff81068f57>] lockdep_rcu_dereference+0x9d/0xa5 [ 103.790577] [<ffffffff8107fac1>] css_id+0x44/0x57 [ 103.790581] [<ffffffff8122e503>] blkiocg_add_blkio_group+0x53/0xad [ 103.790586] [<ffffffff81231936>] cfq_init_queue+0x139/0x32c [ 103.790591] [<ffffffff8121f2d0>] elv_iosched_store+0xbf/0x1bf [ 103.790595] [<ffffffff812263d8>] queue_attr_store+0x70/0x8f [ 103.790599] [<ffffffff8114bfa5>] ? sysfs_write_file+0xe7/0x144 [ 103.790603] [<ffffffff8114bfc6>] sysfs_write_file+0x108/0x144 [ 103.790609] [<ffffffff810f527f>] vfs_write+0xae/0x10b [ 103.790612] [<ffffffff81069863>] ? trace_hardirqs_on_caller+0x10c/0x130 [ 103.790616] [<ffffffff810f539c>] sys_write+0x4a/0x6e [ 103.790622] [<ffffffff81002b5b>] system_call_fastpath+0x16/0x1b [ 103.790625] Located-by: Miles Lane <miles.lane@gmail.com> Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-03block: kill some useless goto's in blk-cgroup.cJens Axboe
goto has its place, but lets cut back on some of the more frivolous uses of it. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-29block: fix bad use of min() on different typesJens Axboe
Just cast the page size to sector_t, that will always fit. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-28cfq-iosched: fix broken cfq_ref_get_cfqf() for CONFIG_BLK_CGROUP=y && ↵Dmitry Monakhov
CFQ_GROUP_IOSCHED=n We should return the cfq_group for this case, not NULL. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-28blkdev: add blkdev_issue_zeroout helper functionDmitry Monakhov
- Add bio_batch helper primitive. This is rather generic primitive for submitting/waiting a complex request which consists of several bios. - blkdev_issue_zeroout() generate number of zero filed write bios. Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-28blkdev: move blkdev_issue helper functions to separate fileDmitry Monakhov
Move blkdev_issue_discard from blk-barrier.c because it is not barrier related. Later the file will be populated by other helpers. Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-28blkdev: allow async blkdev_issue_flush requestsDmitry Monakhov
In some places caller don't want to wait a request to complete. Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-28blkdev: generalize flags for blkdev_issue_fn functionsDmitry Monakhov
The patch just convert all blkdev_issue_xxx function to common set of flags. Wait/allocation semantics preserved. Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-26blk-cgroup: config options re-arrangementVivek Goyal
This patch fixes few usability and configurability issues. o All the cgroup based controller options are configurable from "Genral Setup/Control Group Support/" menu. blkio is the only exception. Hence make this option visible in above menu and make it configurable from there to bring it inline with rest of the cgroup based controllers. o Get rid of CONFIG_DEBUG_CFQ_IOSCHED. This option currently does two things. - Enable printing of cgroup paths in blktrace - Enables CONFIG_DEBUG_BLK_CGROUP, which in turn displays additional stat files in cgroup. If we are using group scheduling, blktrace data is of not really much use if cgroup information is not present. To get this data, currently one has to also enable CONFIG_DEBUG_CFQ_IOSCHED, which in turn brings the overhead of all the additional debug stat files which is not desired. Hence, this patch moves printing of cgroup paths under CONFIG_CFQ_GROUP_IOSCHED. This allows us to get rid of CONFIG_DEBUG_CFQ_IOSCHED completely. Now all the debug stat files are controlled only by CONFIG_DEBUG_BLK_CGROUP which can be enabled through config menu. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Divyesh Shah <dpshah@google.com> Reviewed-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-26blkio: Fix another BUG_ON() crash due to cfqq movement across groupsVivek Goyal
o Once in a while, I was hitting a BUG_ON() in blkio code. empty_time was assuming that upon slice expiry, group can't be marked empty already (except forced dispatch). But this assumption is broken if cfqq can move (group_isolation=0) across groups after receiving a request. I think most likely in this case we got a request in a cfqq and accounted the rq in one group, later while adding the cfqq to tree, we moved the queue to a different group which was already marked empty and after dispatch from slice we found group already marked empty and raised alarm. This patch does not error out if group is already marked empty. This can introduce some empty_time stat error only in case of group_isolation=0. This is better than crashing. In case of group_isolation=1 we should still get same stats as before this patch. [ 222.308546] ------------[ cut here ]------------ [ 222.309311] kernel BUG at block/blk-cgroup.c:236! [ 222.309311] invalid opcode: 0000 [#1] SMP [ 222.309311] last sysfs file: /sys/devices/virtual/block/dm-3/queue/scheduler [ 222.309311] CPU 1 [ 222.309311] Modules linked in: dm_round_robin dm_multipath qla2xxx scsi_transport_fc dm_zero dm_mirror dm_region_hash dm_log dm_mod [last unloaded: scsi_wait_scan] [ 222.309311] [ 222.309311] Pid: 4780, comm: fio Not tainted 2.6.34-rc4-blkio-config #68 0A98h/HP xw8600 Workstation [ 222.309311] RIP: 0010:[<ffffffff8121ad88>] [<ffffffff8121ad88>] blkiocg_set_start_empty_time+0x50/0x83 [ 222.309311] RSP: 0018:ffff8800ba6e79f8 EFLAGS: 00010002 [ 222.309311] RAX: 0000000000000082 RBX: ffff8800a13b7990 RCX: ffff8800a13b7808 [ 222.309311] RDX: 0000000000002121 RSI: 0000000000000082 RDI: ffff8800a13b7a30 [ 222.309311] RBP: ffff8800ba6e7a18 R08: 0000000000000000 R09: 0000000000000001 [ 222.309311] R10: 000000000002f8c8 R11: ffff8800ba6e7ad8 R12: ffff8800a13b78ff [ 222.309311] R13: ffff8800a13b7990 R14: 0000000000000001 R15: ffff8800a13b7808 [ 222.309311] FS: 00007f3beec476f0(0000) GS:ffff880001e40000(0000) knlGS:0000000000000000 [ 222.309311] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 222.309311] CR2: 000000000040e7f0 CR3: 00000000a12d5000 CR4: 00000000000006e0 [ 222.309311] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 222.309311] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 222.309311] Process fio (pid: 4780, threadinfo ffff8800ba6e6000, task ffff8800b3d6bf00) [ 222.309311] Stack: [ 222.309311] 0000000000000001 ffff8800bab17a48 ffff8800bab17a48 ffff8800a13b7800 [ 222.309311] <0> ffff8800ba6e7a68 ffffffff8121da35 ffff880000000001 00ff8800ba5c5698 [ 222.309311] <0> ffff8800ba6e7a68 ffff8800a13b7800 0000000000000000 ffff8800bab17a48 [ 222.309311] Call Trace: [ 222.309311] [<ffffffff8121da35>] __cfq_slice_expired+0x2af/0x3ec [ 222.309311] [<ffffffff8121fd7b>] cfq_dispatch_requests+0x2c8/0x8e8 [ 222.309311] [<ffffffff8120f1cd>] ? spin_unlock_irqrestore+0xe/0x10 [ 222.309311] [<ffffffff8120fb1a>] ? blk_insert_cloned_request+0x70/0x7b [ 222.309311] [<ffffffff81210461>] blk_peek_request+0x191/0x1a7 [ 222.309311] [<ffffffffa0002799>] dm_request_fn+0x38/0x14c [dm_mod] [ 222.309311] [<ffffffff810ae61f>] ? sync_page_killable+0x0/0x35 [ 222.309311] [<ffffffff81210fd4>] __generic_unplug_device+0x32/0x37 [ 222.309311] [<ffffffff81211274>] generic_unplug_device+0x2e/0x3c [ 222.309311] [<ffffffffa00011a6>] dm_unplug_all+0x42/0x5b [dm_mod] [ 222.309311] [<ffffffff8120ca37>] blk_unplug+0x29/0x2d [ 222.309311] [<ffffffff8120ca4d>] blk_backing_dev_unplug+0x12/0x14 [ 222.309311] [<ffffffff81109a7a>] block_sync_page+0x35/0x39 [ 222.309311] [<ffffffff810ae616>] sync_page+0x41/0x4a [ 222.309311] [<ffffffff810ae62d>] sync_page_killable+0xe/0x35 [ 222.309311] [<ffffffff8158aa59>] __wait_on_bit_lock+0x46/0x8f [ 222.309311] [<ffffffff810ae4f5>] __lock_page_killable+0x66/0x6d [ 222.309311] [<ffffffff81056f9c>] ? wake_bit_function+0x0/0x33 [ 222.309311] [<ffffffff810ae528>] lock_page_killable+0x2c/0x2e [ 222.309311] [<ffffffff810afbc5>] generic_file_aio_read+0x361/0x4f0 [ 222.309311] [<ffffffff810ea044>] do_sync_read+0xcb/0x108 [ 222.309311] [<ffffffff811e42f7>] ? security_file_permission+0x16/0x18 [ 222.309311] [<ffffffff810ea6ab>] vfs_read+0xab/0x108 [ 222.309311] [<ffffffff810ea7c8>] sys_read+0x4a/0x6e [ 222.309311] [<ffffffff81002b5b>] system_call_fastpath+0x16/0x1b [ 222.309311] Code: 58 01 00 00 00 48 89 c6 75 0a 48 83 bb 60 01 00 00 00 74 09 48 8d bb a0 00 00 00 eb 35 41 fe cc 74 0d f6 83 c0 01 00 00 04 74 04 <0f> 0b eb fe 48 89 75 e8 e8 be e0 de ff 66 83 8b c0 01 00 00 04 [ 222.309311] RIP [<ffffffff8121ad88>] blkiocg_set_start_empty_time+0x50/0x83 [ 222.309311] RSP <ffff8800ba6e79f8> [ 222.309311] ---[ end trace 32b4f71dffc15712 ]--- Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Divyesh Shah <dpshah@google.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-21blkio: Fix blkio crash during rq stat updateVivek Goyal
blkio + cfq was crashing even when two sequential readers were put in two separate cgroups (group_isolation=0). The reason being that cfqq can migrate across groups based on its being sync-noidle or not, it can happen that at request insertion time, cfqq belonged to one cfqg and at request dispatch time, it belonged to root group. In this case request stats per cgroup can go wrong and it also runs into BUG_ON(). This patch implements rq stashing away a cfq group pointer and not relying on cfqq->cfqg pointer alone for rq stat accounting. [ 65.163523] ------------[ cut here ]------------ [ 65.164301] kernel BUG at block/blk-cgroup.c:117! [ 65.164301] invalid opcode: 0000 [#1] SMP [ 65.164301] last sysfs file: /sys/devices/pci0000:00/0000:00:05.0/0000:60:00.1/host9/rport-9:0-0/target9:0:0/9:0:0:2/block/sde/stat [ 65.164301] CPU 1 [ 65.164301] Modules linked in: dm_round_robin dm_multipath qla2xxx scsi_transport_fc dm_zero dm_mirror dm_region_hash dm_log dm_mod [last unloaded: scsi_wait_scan] [ 65.164301] [ 65.164301] Pid: 4505, comm: fio Not tainted 2.6.34-rc4-blk-for-35 #34 0A98h/HP xw8600 Workstation [ 65.164301] RIP: 0010:[<ffffffff8121924f>] [<ffffffff8121924f>] blkiocg_update_io_remove_stats+0x5b/0xaf [ 65.164301] RSP: 0018:ffff8800ba5a79e8 EFLAGS: 00010046 [ 65.164301] RAX: 0000000000000096 RBX: ffff8800bb268d60 RCX: 0000000000000000 [ 65.164301] RDX: ffff8800bb268eb8 RSI: 0000000000000000 RDI: ffff8800bb268e00 [ 65.164301] RBP: ffff8800ba5a7a08 R08: 0000000000000064 R09: 0000000000000001 [ 65.164301] R10: 0000000000079640 R11: ffff8800a0bd5bf0 R12: ffff8800bab4af01 [ 65.164301] R13: ffff8800bab4af00 R14: ffff8800bb1d8928 R15: 0000000000000000 [ 65.164301] FS: 00007f18f75056f0(0000) GS:ffff880001e40000(0000) knlGS:0000000000000000 [ 65.164301] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 65.164301] CR2: 000000000040e7f0 CR3: 00000000ba52b000 CR4: 00000000000006e0 [ 65.164301] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 65.164301] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 65.164301] Process fio (pid: 4505, threadinfo ffff8800ba5a6000, task ffff8800ba45ae80) [ 65.164301] Stack: [ 65.164301] ffff8800ba5a7a08 ffff8800ba722540 ffff8800bab4af68 ffff8800bab4af68 [ 65.164301] <0> ffff8800ba5a7a38 ffffffff8121d814 ffff8800ba722540 ffff8800bab4af68 [ 65.164301] <0> ffff8800ba722540 ffff8800a08f6800 ffff8800ba5a7a68 ffffffff8121d8ca [ 65.164301] Call Trace: [ 65.164301] [<ffffffff8121d814>] cfq_remove_request+0xe4/0x116 [ 65.164301] [<ffffffff8121d8ca>] cfq_dispatch_insert+0x84/0xe1 [ 65.164301] [<ffffffff8121e833>] cfq_dispatch_requests+0x767/0x8e8 [ 65.164301] [<ffffffff8120e524>] ? submit_bio+0xc3/0xcc [ 65.164301] [<ffffffff810ad657>] ? sync_page_killable+0x0/0x35 [ 65.164301] [<ffffffff8120ea8d>] blk_peek_request+0x191/0x1a7 [ 65.164301] [<ffffffffa000109c>] ? dm_get_live_table+0x44/0x4f [dm_mod] [ 65.164301] [<ffffffffa0002799>] dm_request_fn+0x38/0x14c [dm_mod] [ 65.164301] [<ffffffff810ad657>] ? sync_page_killable+0x0/0x35 [ 65.164301] [<ffffffff8120f600>] __generic_unplug_device+0x32/0x37 [ 65.164301] [<ffffffff8120f8a0>] generic_unplug_device+0x2e/0x3c [ 65.164301] [<ffffffffa00011a6>] dm_unplug_all+0x42/0x5b [dm_mod] [ 65.164301] [<ffffffff8120b063>] blk_unplug+0x29/0x2d [ 65.164301] [<ffffffff8120b079>] blk_backing_dev_unplug+0x12/0x14 [ 65.164301] [<ffffffff81108a82>] block_sync_page+0x35/0x39 [ 65.164301] [<ffffffff810ad64e>] sync_page+0x41/0x4a [ 65.164301] [<ffffffff810ad665>] sync_page_killable+0xe/0x35 [ 65.164301] [<ffffffff81589027>] __wait_on_bit_lock+0x46/0x8f [ 65.164301] [<ffffffff810ad52d>] __lock_page_killable+0x66/0x6d [ 65.164301] [<ffffffff81055fd4>] ? wake_bit_function+0x0/0x33 [ 65.164301] [<ffffffff810ad560>] lock_page_killable+0x2c/0x2e [ 65.164301] [<ffffffff810aebfd>] generic_file_aio_read+0x361/0x4f0 [ 65.164301] [<ffffffff810e906c>] do_sync_read+0xcb/0x108 [ 65.164301] [<ffffffff811e32a3>] ? security_file_permission+0x16/0x18 [ 65.164301] [<ffffffff810e96d3>] vfs_read+0xab/0x108 [ 65.164301] [<ffffffff810e97f0>] sys_read+0x4a/0x6e [ 65.164301] [<ffffffff81002b5b>] system_call_fastpath+0x16/0x1b [ 65.164301] Code: 00 74 1c 48 8b 8b 60 01 00 00 48 85 c9 75 04 0f 0b eb fe 48 ff c9 48 89 8b 60 01 00 00 eb 1a 48 8b 8b 58 01 00 00 48 85 c9 75 04 <0f> 0b eb fe 48 ff c9 48 89 8b 58 01 00 00 45 84 e4 74 16 48 8b [ 65.164301] RIP [<ffffffff8121924f>] blkiocg_update_io_remove_stats+0x5b/0xaf [ 65.164301] RSP <ffff8800ba5a79e8> [ 65.164301] ---[ end trace 1b2b828753032e68 ]--- Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-21block: ensure jiffies wrap is handled correctly in blk_rq_timed_out_timerRichard Kennedy
blk_rq_timed_out_timer() relied on blk_add_timer() never returning a timer value of zero, but commit 7838c15b8dd18e78a523513749e5b54bda07b0cb removed the code that bumped this value when it was zero. Therefore when jiffies is near wrap we could get unlucky & not set the timeout value correctly. This patch uses a flag to indicate that the timeout value was set and so handles jiffies wrap correctly, and it keeps all the logic in one function so should be easier to maintain in the future. Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk> Cc: stable@kernel.org Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-16blkio: Initialize blkg->stats_lock for the root cfqg tooDivyesh Shah
This fixes the lockdep warning reported by Gui Jianfeng. Signed-off-by: Divyesh Shah <dpshah@google.com> Reviewed-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-15blkio: fix for modular blk-cgroup buildDivyesh Shah
After merging the block tree, 20100414's linux-next build (x86_64 allmodconfig) failed like this: ERROR: "get_gendisk" [block/blk-cgroup.ko] undefined! ERROR: "sched_clock" [block/blk-cgroup.ko] undefined! This happens because the two symbols aren't exported and hence not available when blk-cgroup code is built as a module. I've tried to stay consistent with the use of EXPORT_SYMBOL or EXPORT_SYMBOL_GPL with the other symbols in the respective files. Signed-off-by: Divyesh Shah <dpshah@google.com> Acked-by: Gui Jianfeng <guijianfeng@cn.fujitsu.cn> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-14block: ensure jiffies wrap is handled correctly in blk_rq_timed_out_timerRichard Kennedy
blk_rq_timed_out_timer() relied on blk_add_timer() never returning a timer value of zero, but commit 7838c15b8dd18e78a523513749e5b54bda07b0cb removed the code that bumped this value when it was zero. Therefore when jiffies is near wrap we could get unlucky & not set the timeout value correctly. This patch uses a flag to indicate that the timeout value was set and so handles jiffies wrap correctly, and it keeps all the logic in one function so should be easier to maintain in the future. Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-14blkio: Fix compile errorsDivyesh Shah
Fixes compile errors in blk-cgroup code for empty_time stat and a merge fix in CFQ. The first error was when CONFIG_DEBUG_CFQ_IOSCHED is not set. Signed-off-by: Divyesh Shah <dpshah@google.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-13Merge branch 'master' into for-2.6.35Jens Axboe
Conflicts: block/blk-cgroup.c block/cfq-iosched.c Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-13block: Update to io-controller statsDivyesh Shah
Changelog from v1: o Call blkiocg_update_idle_time_stats() at cfq_rq_enqueued() instead of at dispatch time. Changelog from original patchset: (in response to Vivek Goyal's comments) o group blkiocg_update_blkio_group_dequeue_stats() with other DEBUG functions o rename blkiocg_update_set_active_queue_stats() to blkiocg_update_avg_queue_size_stats() o s/request/io/ in blkiocg_update_request_add_stats() and blkiocg_update_request_remove_stats() o Call cfq_del_timer() at request dispatch() instead of blkiocg_update_idle_time_stats() Signed-off-by: Divyesh Shah<dpshah@google.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-13io-controller: Add a new interface "weight_device" for IO-ControllerGui Jianfeng
Currently, IO Controller makes use of blkio.weight to assign weight for all devices. Here a new user interface "blkio.weight_device" is introduced to assign different weights for different devices. blkio.weight becomes the default value for devices which are not configured by "blkio.weight_device" You can use the following format to assigned specific weight for a given device: #echo "major:minor weight" > blkio.weight_device major:minor represents device number. And you can remove weight for a given device as following: #echo "major:minor 0" > blkio.weight_device V1->V2 changes: - use user interface "weight_device" instead of "policy" suggested by Vivek - rename some struct suggested by Vivek - rebase to 2.6-block "for-linus" branch - remove an useless list_empty check pointed out by Li Zefan - some trivial typo fix V2->V3 changes: - Move policy_*_node() functions up to get rid of forward declarations - rename related functions by adding prefix "blkio_" Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-09Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds
* 'for-linus' of git://git.kernel.dk/linux-2.6-block: (34 commits) cfq-iosched: Fix the incorrect timeslice accounting with forced_dispatch loop: Update mtime when writing using aops block: expose the statistics in blkio.time and blkio.sectors for the root cgroup backing-dev: Handle class_create() failure Block: Fix block/elevator.c elevator_get() off-by-one error drbd: lc_element_by_index() never returns NULL cciss: unlock on error path cfq-iosched: Do not merge queues of BE and IDLE classes cfq-iosched: Add additional blktrace log messages in CFQ for easier debugging i2o: Remove the dangerous kobj_to_i2o_device macro block: remove 16 bytes of padding from struct request on 64bits cfq-iosched: fix a kbuild regression block: make CONFIG_BLK_CGROUP visible Remove GENHD_FL_DRIVERFS block: Export max number of segments and max segment size in sysfs block: Finalize conversion of block limits functions block: Fix overrun in lcm() and move it to lib vfs: improve writeback_inodes_wb() paride: fix off-by-one test drbd: fix al-to-on-disk-bitmap for 4k logical_block_size ...
2010-04-09cfq-iosched: Fix the incorrect timeslice accounting with forced_dispatchDivyesh Shah
When CFQ dispatches requests forcefully due to a barrier or changing iosched, it runs through all cfqq's dispatching requests and then expires each queue. However, it does not activate a cfqq before flushing its IOs resulting in using stale values for computing slice_used. This patch fixes it by calling activate queue before flushing reuqests from each queue. This is useful mostly for barrier requests because when the iosched is changing it really doesnt matter if we have incorrect accounting since we're going to break down all structures anyway. We also now expire the current timeslice before moving on with the dispatch to accurately account slice used for that cfqq. Signed-off-by: Divyesh Shah<dpshah@google.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>