- 02 6月, 2015 2 次提交
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由 Tejun Heo 提交于
cancel_dirty_page() had some issues and b9ea2515 ("page_writeback: clean up mess around cancel_dirty_page()") replaced it with account_page_cleaned() which makes the caller responsible for clearing the dirty bit; unfortunately, the planned changes for cgroup writeback support requires synchronization between dirty bit manipulation and stat updates. While we can open-code such synchronization in each account_page_cleaned() callsite, that's gonna be unnecessarily awkward and verbose. This patch revives cancel_dirty_page() but in a more restricted form. All it does is TestClearPageDirty() followed by account_page_cleaned() invocation if the page was dirty. This helper covers all account_page_cleaned() usages except for __delete_from_page_cache() which is a special case anyway and left alone. As this leaves no module user for account_page_cleaned(), EXPORT_SYMBOL() is dropped from it. This patch just revives cancel_dirty_page() as a trivial wrapper to replace equivalent usages and doesn't introduce any functional changes. Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Keith Busch 提交于
Storage controllers may expose multiple block devices that share hardware resources managed by blk-mq. This patch enhances the shared tags so a low-level driver can access the shared resources not tied to the unshared h/w contexts. This way the LLD can dynamically add and delete disks and request queues without having to track all the request_queue hctx's to iterate outstanding tags. Signed-off-by: NKeith Busch <keith.busch@intel.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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- 30 5月, 2015 2 次提交
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由 Jens Axboe 提交于
We don't need to honor chunk sizes for IO that doesn't carry any data. Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Jens Axboe 提交于
We can safely merge anything that wont generate an SG list entry, so if the bio is data-less (discard), don't look at potential SG gaps. Signed-off-by: NJens Axboe <axboe@fb.com>
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- 27 5月, 2015 1 次提交
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由 Julia Lawall 提交于
Remove unneeded variable used to store return value. Generated by: scripts/coccinelle/misc/returnvar.cocci Signed-off-by: NFengguang Wu <fengguang.wu@intel.com> Signed-off-by: NJulia Lawall <julia.lawall@lip6.fr> Signed-off-by: NJens Axboe <axboe@fb.com>
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- 22 5月, 2015 2 次提交
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由 Christoph Hellwig 提交于
Currently dm-multipath has to clone the bios for every request sent to the lower devices, which wastes cpu cycles and ties down memory. This patch instead adds a new REQ_CLONE flag that instructs req_bio_endio to not complete bios attached to a request, which we set on clone requests similar to bios in a flush sequence. With this change I/O errors on a path failure only get propagated to dm-multipath, which can then either resubmit the I/O or complete the bios on the original request. I've done some basic testing of this on a Linux target with ALUA support, and it survives path failures during I/O nicely. Signed-off-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NMike Snitzer <snitzer@redhat.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Mike Snitzer 提交于
Commit c4cf5261 ("bio: skip atomic inc/dec of ->bi_remaining for non-chains") regressed all existing callers that followed this pattern: 1) saving a bio's original bi_end_io 2) wiring up an intermediate bi_end_io 3) restoring the original bi_end_io from intermediate bi_end_io 4) calling bio_endio() to execute the restored original bi_end_io The regression was due to BIO_CHAIN only ever getting set if bio_inc_remaining() is called. For the above pattern it isn't set until step 3 above (step 2 would've needed to establish BIO_CHAIN). As such the first bio_endio(), in step 2 above, never decremented __bi_remaining before calling the intermediate bi_end_io -- leaving __bi_remaining with the value 1 instead of 0. When bio_inc_remaining() occurred during step 3 it brought it to a value of 2. When the second bio_endio() was called, in step 4 above, it should've called the original bi_end_io but it didn't because there was an extra reference that wasn't dropped (due to atomic operations being optimized away since BIO_CHAIN wasn't set upfront). Fix this issue by removing the __bi_remaining management complexity for all callers that use the above pattern -- bio_chain() is the only interface that _needs_ to be concerned with __bi_remaining. For the above pattern callers just expect the bi_end_io they set to get called! Remove bio_endio_nodec() and also remove all bio_inc_remaining() calls that aren't associated with the bio_chain() interface. Also, the bio_inc_remaining() interface has been moved local to bio.c. Fixes: c4cf5261 ("bio: skip atomic inc/dec of ->bi_remaining for non-chains") Reviewed-by: NChristoph Hellwig <hch@lst.de> Reviewed-by: NJan Kara <jack@suse.cz> Signed-off-by: NMike Snitzer <snitzer@redhat.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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- 20 5月, 2015 2 次提交
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由 Ming Lei 提交于
The only possible problem of using mutex_lock() instead of trylock is about deadlock. If there aren't any locks held before calling blkdev_reread_part(), deadlock can't be caused by this conversion. If there are locks held before calling blkdev_reread_part(), and if these locks arn't required in open, close handler and I/O path, deadlock shouldn't be caused too. Both user space's ioctl(BLKRRPART) and md_setup_drive() from init/do_mounts_md.c belongs to the 1st case, so the conversion is safe for the two cases. For loop, the previous patches in this pathset has fixed the ABBA lock dependency, so the conversion is OK. For nbd, tx_lock is held when calling the function: - both open and release won't hold the lock - when blkdev_reread_part() is run, I/O thread has been stopped already, so tx_lock won't be acquired in I/O path at that time. - so the conversion won't cause deadlock for nbd For dasd, both dasd_open(), dasd_release() and request function don't acquire any mutex/semphone, so the conversion should be safe. Reviewed-by: NChristoph Hellwig <hch@lst.de> Tested-by: NJarod Wilson <jarod@redhat.com> Acked-by: NJarod Wilson <jarod@redhat.com> Signed-off-by: NMing Lei <ming.lei@canonical.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Jarod Wilson 提交于
This patch exports blkdev_reread_part() for block drivers, also introduce __blkdev_reread_part(). For some drivers, such as loop, reread of partitions can be run from the release path, and bd_mutex may already be held prior to calling ioctl_by_bdev(bdev, BLKRRPART, 0), so introduce __blkdev_reread_part for use in such cases. CC: Christoph Hellwig <hch@lst.de> CC: Jens Axboe <axboe@kernel.dk> CC: Tejun Heo <tj@kernel.org> CC: Alexander Viro <viro@zeniv.linux.org.uk> CC: Markus Pargmann <mpa@pengutronix.de> CC: Stefan Weinhuber <wein@de.ibm.com> CC: Stefan Haberland <stefan.haberland@de.ibm.com> CC: Sebastian Ott <sebott@linux.vnet.ibm.com> CC: Fabian Frederick <fabf@skynet.be> CC: Ming Lei <ming.lei@canonical.com> CC: David Herrmann <dh.herrmann@gmail.com> CC: Andrew Morton <akpm@linux-foundation.org> CC: Peter Zijlstra <peterz@infradead.org> CC: nbd-general@lists.sourceforge.net CC: linux-s390@vger.kernel.org Reviewed-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NJarod Wilson <jarod@redhat.com> Signed-off-by: NMing Lei <ming.lei@canonical.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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- 19 5月, 2015 5 次提交
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由 Christoph Hellwig 提交于
Stop abusing struct page functionality and the swap end_io handler, and instead add a modified version of the blk-lib.c bio_batch helpers. Also move the block I/O code into swap.c as they are directly tied into each other. Signed-off-by: NChristoph Hellwig <hch@lst.de> Tested-by: NPavel Machek <pavel@ucw.cz> Tested-by: NMing Lin <mlin@kernel.org> Acked-by: NPavel Machek <pavel@ucw.cz> Acked-by: NRafael J. Wysocki <rjw@rjwysocki.net> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Jens Axboe 提交于
Various previous patches removed bits and left holes, collapse them all. Leave the reset start bit where it is, we don't need to change that. Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Christoph Hellwig 提交于
Signed-off-by: NChristoph Hellwig <hch@lst.de> Acked-by: NTejun Heo <tj@kernel.org> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Christoph Hellwig 提交于
Since the big barrier rewrite/removal in 2007 we never fail FLUSH or FUA requests, which means we can remove the magic BIO_EOPNOTSUPP flag to help propagating those to the buffer_head layer. Signed-off-by: NChristoph Hellwig <hch@lst.de> Reviewed-by: NJeff Moyer <jmoyer@redhat.com> Acked-by: NTejun Heo <tj@kernel.org> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Christoph Hellwig 提交于
lockdep gets unhappy about the not disabling irqs when using the queue_lock around it. Instead of trying to fix that up just switch to an atomic_t and get rid of the lock. Signed-off-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NJens Axboe <axboe@fb.com>
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- 09 5月, 2015 6 次提交
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由 Shaohua Li 提交于
Last patch makes plug work for multiple queue case. However it only works for single disk case, because it assumes only one request in the plug list. If a task is accessing multiple disks, eg MD/DM, the assumption is wrong. Let blk_attempt_plug_merge() record request from the same queue. V2: use NULL parameter in !mq case. Fix a bug. Add comments in blk_attempt_plug_merge to make it less (hopefully) confusion. Cc: Jens Axboe <axboe@fb.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: NShaohua Li <shli@fb.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Shaohua Li 提交于
plug is still helpful for workload with IO merge, but it can be harmful otherwise especially with multiple hardware queues, as there is (supposed) no lock contention in this case and plug can introduce latency. For multiple queues, we do limited plug, eg plug only if there is request merge. If a request doesn't have merge with following request, the requet will be dispatched immediately. V2: check blk_queue_nomerges() as suggested by Jeff. Cc: Jens Axboe <axboe@fb.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: NShaohua Li <shli@fb.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Shaohua Li 提交于
If we directly issue a request and it fails, we use blk_mq_merge_queue_io(). But we already assigned bio to a request in blk_mq_bio_to_request. blk_mq_merge_queue_io shouldn't run blk_mq_bio_to_request again. Signed-off-by: NShaohua Li <shli@fb.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Jeff Moyer 提交于
The following appears in blk_sq_make_request: /* * If we have multiple hardware queues, just go directly to * one of those for sync IO. */ We clearly don't have multiple hardware queues, here! This comment was introduced with this commit 07068d5b (blk-mq: split make request handler for multi and single queue): We want slightly different behavior from them: - On single queue devices, we currently use the per-process plug for deferred IO and for merging. - On multi queue devices, we don't use the per-process plug, but we want to go straight to hardware for SYNC IO. The old code had this: use_plug = !is_flush_fua && ((q->nr_hw_queues == 1) || !is_sync); and that was converted to: use_plug = !is_flush_fua && !is_sync; which is not equivalent. For the single queue case, that second half of the && expression is always true. So, what I think was actually inteded follows (and this more closely matches what is done in blk_queue_bio). V2: delete the 'likely', which should not be a big deal Signed-off-by: NJeff Moyer <jmoyer@redhat.com> Signed-off-by: NShaohua Li <shli@fb.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Shaohua Li 提交于
block plug callback could sleep, so we introduce a parameter 'from_schedule' and corresponding drivers can use it to destinguish a schedule plug flush or a plug finish. Unfortunately io_schedule_out still uses blk_flush_plug(). This causes below output (Note, I added a might_sleep() in raid1_unplug to make it trigger faster, but the whole thing doesn't matter if I add might_sleep). In raid1/10, this can cause deadlock. This patch makes io_schedule_out always uses blk_schedule_flush_plug. This should only impact drivers (as far as I know, raid 1/10) which are sensitive to the 'from_schedule' parameter. [ 370.817949] ------------[ cut here ]------------ [ 370.817960] WARNING: CPU: 7 PID: 145 at ../kernel/sched/core.c:7306 __might_sleep+0x7f/0x90() [ 370.817969] do not call blocking ops when !TASK_RUNNING; state=2 set at [<ffffffff81092fcf>] prepare_to_wait+0x2f/0x90 [ 370.817971] Modules linked in: raid1 [ 370.817976] CPU: 7 PID: 145 Comm: kworker/u16:9 Tainted: G W 4.0.0+ #361 [ 370.817977] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140709_153802- 04/01/2014 [ 370.817983] Workqueue: writeback bdi_writeback_workfn (flush-9:1) [ 370.817985] ffffffff81cd83be ffff8800ba8cb298 ffffffff819dd7af 0000000000000001 [ 370.817988] ffff8800ba8cb2e8 ffff8800ba8cb2d8 ffffffff81051afc ffff8800ba8cb2c8 [ 370.817990] ffffffffa00061a8 000000000000041e 0000000000000000 ffff8800ba8cba28 [ 370.817993] Call Trace: [ 370.817999] [<ffffffff819dd7af>] dump_stack+0x4f/0x7b [ 370.818002] [<ffffffff81051afc>] warn_slowpath_common+0x8c/0xd0 [ 370.818004] [<ffffffff81051b86>] warn_slowpath_fmt+0x46/0x50 [ 370.818006] [<ffffffff81092fcf>] ? prepare_to_wait+0x2f/0x90 [ 370.818008] [<ffffffff81092fcf>] ? prepare_to_wait+0x2f/0x90 [ 370.818010] [<ffffffff810776ef>] __might_sleep+0x7f/0x90 [ 370.818014] [<ffffffffa0000c03>] raid1_unplug+0xd3/0x170 [raid1] [ 370.818024] [<ffffffff81421d9a>] blk_flush_plug_list+0x8a/0x1e0 [ 370.818028] [<ffffffff819e3550>] ? bit_wait+0x50/0x50 [ 370.818031] [<ffffffff819e21b0>] io_schedule_timeout+0x130/0x140 [ 370.818033] [<ffffffff819e3586>] bit_wait_io+0x36/0x50 [ 370.818034] [<ffffffff819e31b5>] __wait_on_bit+0x65/0x90 [ 370.818041] [<ffffffff8125b67c>] ? ext4_read_block_bitmap_nowait+0xbc/0x630 [ 370.818043] [<ffffffff819e3550>] ? bit_wait+0x50/0x50 [ 370.818045] [<ffffffff819e3302>] out_of_line_wait_on_bit+0x72/0x80 [ 370.818047] [<ffffffff810935e0>] ? autoremove_wake_function+0x40/0x40 [ 370.818050] [<ffffffff811de744>] __wait_on_buffer+0x44/0x50 [ 370.818053] [<ffffffff8125ae80>] ext4_wait_block_bitmap+0xe0/0xf0 [ 370.818058] [<ffffffff812975d6>] ext4_mb_init_cache+0x206/0x790 [ 370.818062] [<ffffffff8114bc6c>] ? lru_cache_add+0x1c/0x50 [ 370.818064] [<ffffffff81297c7e>] ext4_mb_init_group+0x11e/0x200 [ 370.818066] [<ffffffff81298231>] ext4_mb_load_buddy+0x341/0x360 [ 370.818068] [<ffffffff8129a1a3>] ext4_mb_find_by_goal+0x93/0x2f0 [ 370.818070] [<ffffffff81295b54>] ? ext4_mb_normalize_request+0x1e4/0x5b0 [ 370.818072] [<ffffffff8129ab67>] ext4_mb_regular_allocator+0x67/0x460 [ 370.818074] [<ffffffff81295b54>] ? ext4_mb_normalize_request+0x1e4/0x5b0 [ 370.818076] [<ffffffff8129ca4b>] ext4_mb_new_blocks+0x4cb/0x620 [ 370.818079] [<ffffffff81290956>] ext4_ext_map_blocks+0x4c6/0x14d0 [ 370.818081] [<ffffffff812a4d4e>] ? ext4_es_lookup_extent+0x4e/0x290 [ 370.818085] [<ffffffff8126399d>] ext4_map_blocks+0x14d/0x4f0 [ 370.818088] [<ffffffff81266fbd>] ext4_writepages+0x76d/0xe50 [ 370.818094] [<ffffffff81149691>] do_writepages+0x21/0x50 [ 370.818097] [<ffffffff811d5c00>] __writeback_single_inode+0x60/0x490 [ 370.818099] [<ffffffff811d630a>] writeback_sb_inodes+0x2da/0x590 [ 370.818103] [<ffffffff811abf4b>] ? trylock_super+0x1b/0x50 [ 370.818105] [<ffffffff811abf4b>] ? trylock_super+0x1b/0x50 [ 370.818107] [<ffffffff811d665f>] __writeback_inodes_wb+0x9f/0xd0 [ 370.818109] [<ffffffff811d69db>] wb_writeback+0x34b/0x3c0 [ 370.818111] [<ffffffff811d70df>] bdi_writeback_workfn+0x23f/0x550 [ 370.818116] [<ffffffff8106bbd8>] process_one_work+0x1c8/0x570 [ 370.818117] [<ffffffff8106bb5b>] ? process_one_work+0x14b/0x570 [ 370.818119] [<ffffffff8106c09b>] worker_thread+0x11b/0x470 [ 370.818121] [<ffffffff8106bf80>] ? process_one_work+0x570/0x570 [ 370.818124] [<ffffffff81071868>] kthread+0xf8/0x110 [ 370.818126] [<ffffffff81071770>] ? kthread_create_on_node+0x210/0x210 [ 370.818129] [<ffffffff819e9322>] ret_from_fork+0x42/0x70 [ 370.818131] [<ffffffff81071770>] ? kthread_create_on_node+0x210/0x210 [ 370.818132] ---[ end trace 7b4deb71e68b6605 ]--- V2: don't change ->in_iowait Cc: NeilBrown <neilb@suse.de> Signed-off-by: NShaohua Li <shli@fb.com> Reviewed-by: NJeff Moyer <jmoyer@redhat.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Shaohua Li 提交于
Current code looks like inner plug gets flushed with a blk_finish_plug(). Actually it's a nop. All requests/callbacks are added to current->plug, while only outmost plug is assigned to current->plug. So inner plug always has empty request/callback list, which makes blk_flush_plug_list() a nop. This tries to make the code more clear. Signed-off-by: NShaohua Li <shli@fb.com> Reviewed-by: NJeff Moyer <jmoyer@redhat.com> Reviewed-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NJens Axboe <axboe@fb.com>
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- 06 5月, 2015 9 次提交
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由 Christoph Hellwig 提交于
Signed-off-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Christoph Hellwig 提交于
This removes the request types and hacks from the block code and into the old IDE driver. There is a small amunt of code duplication due to this, but it's not too bad. Signed-off-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Christoph Hellwig 提交于
Signed-off-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Christoph Hellwig 提交于
Signed-off-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Christoph Hellwig 提交于
These values are only used by the IDE driver, so move them into it by allowing drivers to take cmd_type values after the first private one. Note that we have to turn cmd_type into a plain unsigned integer so that gcc doesn't complain about mismatching enum types. Signed-off-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Christoph Hellwig 提交于
Signed-off-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Jens Axboe 提交于
Struct bio has a reference count that controls when it can be freed. Most uses cases is allocating the bio, which then returns with a single reference to it, doing IO, and then dropping that single reference. We can remove this atomic_dec_and_test() in the completion path, if nobody else is holding a reference to the bio. If someone does call bio_get() on the bio, then we flag the bio as now having valid count and that we must properly honor the reference count when it's being put. Tested-by: NRobert Elliott <elliott@hp.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Jens Axboe 提交于
Struct bio has an atomic ref count for chained bio's, and we use this to know when to end IO on the bio. However, most bio's are not chained, so we don't need to always introduce this atomic operation as part of ending IO. Add a helper to elevate the bi_remaining count, and flag the bio as now actually needing the decrement at end_io time. Rename the field to __bi_remaining to catch any current users of this doing the incrementing manually. For high IOPS workloads, this reduces the overhead of bio_endio() substantially. Tested-by: NRobert Elliott <elliott@hp.com> Acked-by: NKent Overstreet <kent.overstreet@gmail.com> Reviewed-by: NJan Kara <jack@suse.cz> Signed-off-by: NJens Axboe <axboe@fb.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6由 Linus Torvalds 提交于
Pull crypto fixes from Herbert Xu: "This fixes a build problem with bcm63xx and yet another fix to the memzero_explicit function to ensure that the memset is not elided" * git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: hwrng: bcm63xx - Fix driver compilation lib: make memzero_explicit more robust against dead store elimination
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- 05 5月, 2015 1 次提交
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git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media由 Linus Torvalds 提交于
Pull media fixes from Mauro Carvalho Chehab: "Three driver fixes: - fix for omap4, fixing a regression due to a subsystem API that got removed for 4.1 (commit efde2346); - fix for one of the formats supported by Marvel ccic driver; - fix rcar_vin driver that, when stopping abnormally, the driver can't return from wait_for_completion" * tag 'media/v4.1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: [media] v4l: omap4iss: Replace outdated OMAP4 control pad API with syscon [media] media: soc_camera: rcar_vin: Fix wait_for_completion [media] marvell-ccic: fix Y'CbCr ordering
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- 04 5月, 2015 10 次提交
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由 Álvaro Fernández Rojas 提交于
- s/clk_didsable_unprepare/clk_disable_unprepare - s/prov/priv - s/error/ret (bcm63xx_rng_probe) Fixes: 6229c160 ("hwrng: bcm63xx - make use of devm_hwrng_register") Signed-off-by: NÁlvaro Fernández Rojas <noltari@gmail.com> Acked-by: NFlorian Fainelli <f.fainelli@gmail.com> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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由 Daniel Borkmann 提交于
In commit 0b053c95 ("lib: memzero_explicit: use barrier instead of OPTIMIZER_HIDE_VAR"), we made memzero_explicit() more robust in case LTO would decide to inline memzero_explicit() and eventually find out it could be elimiated as dead store. While using barrier() works well for the case of gcc, recent efforts from LLVMLinux people suggest to use llvm as an alternative to gcc, and there, Stephan found in a simple stand-alone user space example that llvm could nevertheless optimize and thus elimitate the memset(). A similar issue has been observed in the referenced llvm bug report, which is regarded as not-a-bug. Based on some experiments, icc is a bit special on its own, while it doesn't seem to eliminate the memset(), it could do so with an own implementation, and then result in similar findings as with llvm. The fix in this patch now works for all three compilers (also tested with more aggressive optimization levels). Arguably, in the current kernel tree it's more of a theoretical issue, but imho, it's better to be pedantic about it. It's clearly visible with gcc/llvm though, with the below code: if we would have used barrier() only here, llvm would have omitted clearing, not so with barrier_data() variant: static inline void memzero_explicit(void *s, size_t count) { memset(s, 0, count); barrier_data(s); } int main(void) { char buff[20]; memzero_explicit(buff, sizeof(buff)); return 0; } $ gcc -O2 test.c $ gdb a.out (gdb) disassemble main Dump of assembler code for function main: 0x0000000000400400 <+0>: lea -0x28(%rsp),%rax 0x0000000000400405 <+5>: movq $0x0,-0x28(%rsp) 0x000000000040040e <+14>: movq $0x0,-0x20(%rsp) 0x0000000000400417 <+23>: movl $0x0,-0x18(%rsp) 0x000000000040041f <+31>: xor %eax,%eax 0x0000000000400421 <+33>: retq End of assembler dump. $ clang -O2 test.c $ gdb a.out (gdb) disassemble main Dump of assembler code for function main: 0x00000000004004f0 <+0>: xorps %xmm0,%xmm0 0x00000000004004f3 <+3>: movaps %xmm0,-0x18(%rsp) 0x00000000004004f8 <+8>: movl $0x0,-0x8(%rsp) 0x0000000000400500 <+16>: lea -0x18(%rsp),%rax 0x0000000000400505 <+21>: xor %eax,%eax 0x0000000000400507 <+23>: retq End of assembler dump. As gcc, clang, but also icc defines __GNUC__, it's sufficient to define this in compiler-gcc.h only to be picked up. For a fallback or otherwise unsupported compiler, we define it as a barrier. Similarly, for ecc which does not support gcc inline asm. Reference: https://llvm.org/bugs/show_bug.cgi?id=15495Reported-by: NStephan Mueller <smueller@chronox.de> Tested-by: NStephan Mueller <smueller@chronox.de> Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Stephan Mueller <smueller@chronox.de> Cc: Hannes Frederic Sowa <hannes@stressinduktion.org> Cc: mancha security <mancha1@zoho.com> Cc: Mark Charlebois <charlebm@gmail.com> Cc: Behan Webster <behanw@converseincode.com> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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由 Linus Torvalds 提交于
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git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4由 Linus Torvalds 提交于
Pull ext4 fixes from Ted Ts'o: "Some miscellaneous bug fixes and some final on-disk and ABI changes for ext4 encryption which provide better security and performance" * tag 'for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: fix growing of tiny filesystems ext4: move check under lock scope to close a race. ext4: fix data corruption caused by unwritten and delayed extents ext4 crypto: remove duplicated encryption mode definitions ext4 crypto: do not select from EXT4_FS_ENCRYPTION ext4 crypto: add padding to filenames before encrypting ext4 crypto: simplify and speed up filename encryption
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git://people.freedesktop.org/~airlied/linux由 Linus Torvalds 提交于
Pull drm fixes from Dave Airlie: "One intel fix, one rockchip fix, and a bunch of radeon fixes for some regressions from audio rework and vm stability" * 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: drm/i915/chv: Implement WaDisableShadowRegForCpd drm/radeon: fix userptr return value checking (v2) drm/radeon: check new address before removing old one drm/radeon: reset BOs address after clearing it. drm/radeon: fix lockup when BOs aren't part of the VM on release drm/radeon: add SI DPM quirk for Sapphire R9 270 Dual-X 2G GDDR5 drm/radeon: adjust pll when audio is not enabled drm/radeon: only enable audio streams if the monitor supports it drm/radeon: only mark audio as connected if the monitor supports it (v3) drm/radeon/audio: don't enable packets until the end drm/radeon: drop dce6_dp_enable drm/radeon: fix ordering of AVI packet setup drm/radeon: Use drm_calloc_ab for CS relocs drm/rockchip: fix error check when getting irq MAINTAINERS: add entry for Rockchip drm drivers
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git://anongit.freedesktop.org/drm-intel由 Dave Airlie 提交于
Just a single intel fix * tag 'drm-intel-fixes-2015-04-30' of git://anongit.freedesktop.org/drm-intel: drm/i915/chv: Implement WaDisableShadowRegForCpd
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https://github.com/markyzq/kernel-drm-rockchip由 Dave Airlie 提交于
one fix and maintainers update * 'drm-next0420' of https://github.com/markyzq/kernel-drm-rockchip: drm/rockchip: fix error check when getting irq MAINTAINERS: add entry for Rockchip drm drivers
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git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi由 Linus Torvalds 提交于
Pull SCSI fixes from James Bottomley: "This is three logical fixes (as 5 patches). The 3ware class of drivers were causing an oops with multiqueue by tearing down the command mappings after completing the command (where the variables in the command used to tear down the mapping were no-longer valid). There's also a fix for the qnap iscsi target which was choking on us sending it commands that were too long and a fix for the reworked aha1542 allocating GFP_KERNEL under a lock" * tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: 3w-9xxx: fix command completion race 3w-xxxx: fix command completion race 3w-sas: fix command completion race aha1542: Allocate memory before taking a lock SCSI: add 1024 max sectors black list flag
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git://git.infradead.org/users/vkoul/slave-dma由 Linus Torvalds 提交于
Pull slave dmaengine fixes from Vinod Koul: "Here are the fixes in dmaengine subsystem for rc2: - privatecnt fix for slave dma request API by Christopher - warn fix for PM ifdef in usb-dmac by Geert - fix hardware dependency for xgene by Jean" * 'next' of git://git.infradead.org/users/vkoul/slave-dma: dmaengine: increment privatecnt when using dma_get_any_slave_channel dmaengine: xgene: Set hardware dependency dmaengine: usb-dmac: Protect PM-only functions to kill warning
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git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux由 Linus Torvalds 提交于
Pull powerpc fixes from Michael Ellerman: - build fix for SMP=n in book3s_xics.c - fix for Daniel's pci_controller_ops on powernv. - revert the TM syscall abort patch for now. - CPU affinity fix from Nathan. - two EEH fixes from Gavin. - fix for CR corruption from Sam. - selftest build fix. * tag 'powerpc-4.1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux: powerpc/powernv: Restore non-volatile CRs after nap powerpc/eeh: Delay probing EEH device during hotplug powerpc/eeh: Fix race condition in pcibios_set_pcie_reset_state() powerpc/pseries: Correct cpu affinity for dlpar added cpus selftests/powerpc: Fix the pmu install rule Revert "powerpc/tm: Abort syscalls in active transactions" powerpc/powernv: Fix early pci_controller_ops loading. powerpc/kvm: Fix SMP=n build error in book3s_xics.c
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