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2023-02-14dm: correct block comments format.Heinz Mauelshagen26-177/+315
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-02-14dm: address indent/space issuesHeinz Mauelshagen12-25/+24
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-02-14dm: address space issues relative to switch/while/for/...Heinz Mauelshagen7-12/+12
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-02-14dm: avoid initializing static variablesHeinz Mauelshagen4-5/+5
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-02-14dm: enclose complex macros into parentheses where possibleHeinz Mauelshagen2-4/+5
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-02-14dm: avoid assignment in if conditionsHeinz Mauelshagen4-9/+17
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-02-14dm: change "unsigned" to "unsigned int"Heinz Mauelshagen82-1016/+1016
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-02-14dm: use fsleep() instead of msleep() for deterministic sleep durationHeinz Mauelshagen4-10/+10
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-02-14dm: prefer kmap_local_page() instead of deprecated kmap_atomic()Heinz Mauelshagen2-18/+18
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-02-14dm: add missing SPDX-License-IndentifiersHeinz Mauelshagen100-14/+101
'GPL-2.0-only' is used instead of 'GPL-2.0' because SPDX has deprecated its use. Suggested-by: John Wiele <jwiele@redhat.com> Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-02-14dm: send just one event on resize, not twoMikulas Patocka3-18/+24
Device mapper sends an uevent when the device is suspended, using the function set_capacity_and_notify. However, this causes a race condition with udev. Udev skips scanning dm devices that are suspended. If we send an uevent while we are suspended, udev will be racing with device mapper resume code. If the device mapper resume code wins the race, udev will process the uevent after the device is resumed and it will properly scan the device. However, if udev wins the race, it will receive the uevent, find out that the dm device is suspended and skip scanning the device. This causes bugs such as systemd unmounting the device - see https://bugzilla.redhat.com/show_bug.cgi?id=2158628 This commit fixes this race. We replace the function set_capacity_and_notify with set_capacity, so that the uevent is not sent at this point. In do_resume, we detect if the capacity has changed and we pass a boolean variable need_resize_uevent to dm_kobject_uevent. dm_kobject_uevent adds "RESIZE=1" to the uevent if need_resize_uevent is set. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Tested-by: Peter Rajnoha <prajnoha@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-02-12dm table: check that a dm device doesn't reference itselfBenjamin Marzinski1-0/+2
If a DM device's table references itself, it will crash the kernel with an infinite recursion. Check for a self-reference in dm_get_device(). This is a quick check, but it won't catch more complicated circular references. Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-02-12dm raid: fix some spelling mistakes in commentsYu Zhe1-3/+3
Signed-off-by: Yu Zhe <yuzhe@nfschina.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-02-02dm verity: stop using WQ_UNBOUND for verify_wqNathan Huckleberry1-5/+1
Setting WQ_UNBOUND increases scheduler latency on ARM64. This is likely due to the asymmetric architecture of ARM64 processors. I've been unable to reproduce the results that claim WQ_UNBOUND gives a performance boost on x86-64. This flag is causing performance issues for multiple subsystems within Android. Notably, the same slowdown exists for decompression with EROFS. | open-prebuilt-camera | WQ_UNBOUND | ~WQ_UNBOUND | |-----------------------|------------|---------------| | verity wait time (us) | 11746 | 119 (-98%) | | erofs wait time (us) | 357805 | 174205 (-51%) | | sha256 ramdisk random read | WQ_UNBOUND | ~WQ_UNBOUND | |----------------------------|-----------=---|-------------| | arm64 (accelerated) | bw=42.4MiB/s | bw=212MiB/s | | arm64 (generic) | bw=16.5MiB/s | bw=48MiB/s | | x86_64 (generic) | bw=233MiB/s | bw=230MiB/s | Using a alloc_workqueue() @max_active arg of num_online_cpus() only made sense with WQ_UNBOUND. Switch the @max_active arg to 0 (aka default, which is 256 per-cpu). Also, eliminate 'wq_flags' since it really doesn't serve a purpose. Cc: Sami Tolvanen <samitolvanen@google.com> Cc: Eric Biggers <ebiggers@kernel.org> Signed-off-by: Nathan Huckleberry <nhuck@google.com> Reviewed-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-02-02dm integrity: Remove bi_sector that's only used by commented debug codeJiapeng Chong1-7/+0
drivers/md/dm-integrity.c:1738:13: warning: variable 'bi_sector' set but not used. Reported-by: Abaci Robot <abaci@linux.alibaba.com> Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=3895 Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-02-02dm crypt: Slightly simplify crypt_set_keyring_key()Christophe JAILLET1-1/+1
Use strchr() instead of strpbrk() when there is only 1 element in the set of characters to look for. This potentially saves a few cycles, but gcc does already account for optimizing this pattern thanks to it's fold_builtin_strpbrk(). Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-02-02dm ioctl: drop always-false conditionSergey Shtylyov1-2/+1
The expression 'indata[3] > ULONG_MAX' always evaluates to false since indata[] is declared as an array of *unsigned long* elements and #define ULONG_MAX represents the max value of that exact type... Note that gcc seems to be able to detect the dead code here and eliminate this check anyway... Found by Linux Verification Center (linuxtesting.org) with the SVACE static analysis tool. Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru> Reviewed-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-02-02dm flakey: fix logic when corrupting a bioMikulas Patocka1-10/+13
If "corrupt_bio_byte" is set to corrupt reads and corrupt_bio_flags is used, dm-flakey would erroneously return all writes as errors. Likewise, if "corrupt_bio_byte" is set to corrupt writes, dm-flakey would return errors for all reads. Fix the logic so that if fc->corrupt_bio_byte is non-zero, dm-flakey will not abort reads on writes with an error. Cc: stable@vger.kernel.org Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-02-01dm flakey: fix a bug with 32-bit highmem systemsMikulas Patocka1-1/+2
The function page_address does not work with 32-bit systems with high memory. Use bvec_kmap_local/kunmap_local instead. Cc: stable@vger.kernel.org Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-02-01dm flakey: don't corrupt the zero pageMikulas Patocka1-2/+5
When we need to zero some range on a block device, the function __blkdev_issue_zero_pages submits a write bio with the bio vector pointing to the zero page. If we use dm-flakey with corrupt bio writes option, it will corrupt the content of the zero page which results in crashes of various userspace programs. Glibc assumes that memory returned by mmap is zeroed and it uses it for calloc implementation; if the newly mapped memory is not zeroed, calloc will return non-zeroed memory. Fix this bug by testing if the page is equal to ZERO_PAGE(0) and avoiding the corruption in this case. Cc: stable@vger.kernel.org Fixes: a00f5276e266 ("dm flakey: Properly corrupt multi-page bios.") Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-01-30dm cache: Add some documentation to dm-cache-background-tracker.hJoe Thornber1-3/+37
Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-01-30dm cache: free background tracker's queued work in btracker_destroyJoe Thornber1-0/+8
Otherwise the kernel can BUG with: [ 2245.426978] ============================================================================= [ 2245.435155] BUG bt_work (Tainted: G B W ): Objects remaining in bt_work on __kmem_cache_shutdown() [ 2245.445233] ----------------------------------------------------------------------------- [ 2245.445233] [ 2245.454879] Slab 0x00000000b0ce2b30 objects=64 used=2 fp=0x000000000a3c6a4e flags=0x17ffffc0000200(slab|node=0|zone=2|lastcpupid=0x1fffff) [ 2245.467300] CPU: 7 PID: 10805 Comm: lvm Kdump: loaded Tainted: G B W 6.0.0-rc2 #19 [ 2245.476078] Hardware name: Dell Inc. PowerEdge R7525/0590KW, BIOS 2.5.6 10/06/2021 [ 2245.483646] Call Trace: [ 2245.486100] <TASK> [ 2245.488206] dump_stack_lvl+0x34/0x48 [ 2245.491878] slab_err+0x95/0xcd [ 2245.495028] __kmem_cache_shutdown.cold+0x31/0x136 [ 2245.499821] kmem_cache_destroy+0x49/0x130 [ 2245.503928] btracker_destroy+0x12/0x20 [dm_cache] [ 2245.508728] smq_destroy+0x15/0x60 [dm_cache_smq] [ 2245.513435] dm_cache_policy_destroy+0x12/0x20 [dm_cache] [ 2245.518834] destroy+0xc0/0x110 [dm_cache] [ 2245.522933] dm_table_destroy+0x5c/0x120 [dm_mod] [ 2245.527649] __dm_destroy+0x10e/0x1c0 [dm_mod] [ 2245.532102] dev_remove+0x117/0x190 [dm_mod] [ 2245.536384] ctl_ioctl+0x1a2/0x290 [dm_mod] [ 2245.540579] dm_ctl_ioctl+0xa/0x20 [dm_mod] [ 2245.544773] __x64_sys_ioctl+0x8a/0xc0 [ 2245.548524] do_syscall_64+0x5c/0x90 [ 2245.552104] ? syscall_exit_to_user_mode+0x12/0x30 [ 2245.556897] ? do_syscall_64+0x69/0x90 [ 2245.560648] ? do_syscall_64+0x69/0x90 [ 2245.564394] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 2245.569447] RIP: 0033:0x7fe52583ec6b ... [ 2245.646771] ------------[ cut here ]------------ [ 2245.651395] kmem_cache_destroy bt_work: Slab cache still has objects when called from btracker_destroy+0x12/0x20 [dm_cache] [ 2245.651408] WARNING: CPU: 7 PID: 10805 at mm/slab_common.c:478 kmem_cache_destroy+0x128/0x130 Found using: lvm2-testsuite --only "cache-single-split.sh" Ben bisected and found that commit 0495e337b703 ("mm/slab_common: Deleting kobject in kmem_cache_destroy() without holding slab_mutex/cpu_hotplug_lock") first exposed dm-cache's incomplete cleanup of its background tracker work objects. Reported-by: Benjamin Marzinski <bmarzins@redhat.com> Tested-by: Benjamin Marzinski <bmarzins@redhat.com> Cc: stable@vger.kernel.org # 6.0+ Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-01-30dm: improve shrinker debug namesMike Snitzer2-2/+2
Commit e33c267ab70d ("mm: shrinkers: provide shrinkers with names") chose some fairly bad names for DM's shrinkers. Fixes: e33c267ab70d ("mm: shrinkers: provide shrinkers with names") Signed-off-by : Mike Snitzer <snitzer@kernel.org>
2023-01-30block: Default to use cgroup support for BFQUlf Hansson1-0/+1
Assuming that both Kconfig options, BLK_CGROUP and IOSCHED_BFQ are set, we most likely want cgroup support for BFQ too (BFQ_GROUP_IOSCHED), so let's make it default y. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Link: https://lore.kernel.org/r/20230130121240.159456-1-ulf.hansson@linaro.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-30block, bfq: remove unused bfq_wr_max_time in struct bfq_dataKemeng Shi2-6/+0
bfqd->bfq_wr_max_time is set to 0 in bfq_init_queue and is never changed. It is only used in bfq_wr_duration when bfq_wr_max_time > 0 which never meets, so bfqd->bfq_wr_max_time is not used actually. Just remove it. Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20230116095153.3810101-9-shikemeng@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-30block, bfq: remove unnecessary goto tag in bfq_dispatch_rq_from_bfqqKemeng Shi1-6/+3
We jump to tag only for returning current rq. Return directly to remove this tag. Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Link: https://lore.kernel.org/r/20230116095153.3810101-8-shikemeng@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-30block, bfq: remove redundant check in bfq_put_cooperatorKemeng Shi1-2/+0
We have already avoided a circular list in bfq_setup_merge (see comments in bfq_setup_merge() for details), so bfq_queue will not appear in it's new_bfqq list. Just remove this check. Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20230116095153.3810101-7-shikemeng@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-30block, bfq: remove unnecessary dereference to get async_bfqqKemeng Shi1-1/+1
The async_bfqq is assigned with bfqq->bic->bfqq[0], use it directly. Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20230116095153.3810101-6-shikemeng@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-30block, bfq: use helper macro RQ_BFQQ to get bfqq of requestKemeng Shi1-3/+3
Use helper macro RQ_BFQQ to get bfqq of request. Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20230116095153.3810101-5-shikemeng@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-30block, bfq: initialize bfqq->decrease_time_jif correctlyKemeng Shi1-0/+2
Inject limit is updated or reset when time_is_before_eq_jiffies( decrease_time_jif + several msecs) or think-time state changes. decrease_time_jif is initialized to 0 and will be set to current jiffies when inject limit is updated or reset. If the jiffies is slightly greater than LONG_MAX, time_is_after_eq_jiffies(0) will keep for a long time, so as time_is_after_eq_jiffies(decrease_time_jif + several msecs). If the think-time state never chages, then the injection will not work as expected for long time. To be more specific: Function bfq_update_inject_limit maybe triggered when jiffies pasts decrease_time_jif + msecs_to_jiffies(10) in bfq_add_request by setting bfqd->wait_dispatch to true. Function bfq_reset_inject_limit are called in two conditions: 1. jiffies pasts bfqq->decrease_time_jif + msecs_to_jiffies(1000) in function bfq_add_request. 2. jiffies pasts bfqq->decrease_time_jif + msecs_to_jiffies(100) or bfq think-time state change from short to long. Fix this by initializing bfqq->decrease_time_jif to current jiffies to trigger service injection soon when service injection conditions are met. Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20230116095153.3810101-4-shikemeng@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-30block, bfq: remove unsed parameter reason in bfq_bfqq_is_slowKemeng Shi1-3/+2
Parameter reason is never used, just remove it. Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20230116095153.3810101-3-shikemeng@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-30block, bfq: correctly raise inject limit in bfq_choose_bfqq_for_injectionKemeng Shi1-6/+4
Function bfq_choose_bfqq_for_injection may temporarily raise inject limit to one request if current inject_limit is 0 before search of the source queue for injection. However the search below will reset inject limit to bfqd->in_service_queue which is zero for raised inject limit. Then the temporarily raised inject limit never works as expected. Assigment limit to bfqd->in_service_queue in search is needed as limit maybe overwriten to min_t(unsigned int, 1, limit) for condition that a large in-flight request is on non-rotational devices in found queue. So we need to reset limit to bfqd->in_service_queue for normal case. Actually, we have already make sure bfqd->rq_in_driver is < limit before search, then -Limit is >= 1 as bfqd->rq_in_driver is >= 0. Then min_t(unsigned int, 1, limit) is always 1. So we can simply check bfqd->rq_in_driver with 1 instead of result of min_t(unsigned int, 1, limit) for larget request in non-rotational device case to avoid overwritting limit and the bug is gone. -For normal case, we have already check bfqd->rq_in_driver is < limit, so we can return found bfqq unconditionally to remove unncessary check. Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20230116095153.3810101-2-shikemeng@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-30sbitmap: correct wake_batch recalculation to avoid potential IO hungKemeng Shi1-4/+1
Commit 180dccb0dba4f ("blk-mq: fix tag_get wait task can't be awakened") mentioned that in case of shared tags, there could be just one real active hctx(queue) because of lazy detection of tag idle. Then driver tag allocation may wait forever on this real active hctx(queue) if wake_batch is > hctx_max_depth where hctx_max_depth is available tags depth for the actve hctx(queue). However, the condition wake_batch > hctx_max_depth is not strong enough to avoid IO hung as the sbitmap_queue_wake_up will only wake up one wait queue for each wake_batch even though there is only one waiter in the woken wait queue. After this, there is only one tag to free and wake_batch may not be reached anymore. Commit 180dccb0dba4f ("blk-mq: fix tag_get wait task can't be awakened") methioned that driver tag allocation may wait forever. Actually, the inactive hctx(queue) will be truely idle after at most 30 seconds and will call blk_mq_tag_wakeup_all to wake one waiter per wait queue to break the hung. But IO hung for 30 seconds is also not acceptable. Set batch size to small enough that depth of the shared hctx(queue) is enough to wake up all of the queues like sbq_calc_wake_batch do to fix this potential IO hung. Although hctx_max_depth will be clamped to at least 4 while wake_batch recalculation does not do the clamp, the wake_batch will be always recalculated to 1 when hctx_max_depth <= 4. Fixes: 180dccb0dba4 ("blk-mq: fix tag_get wait task can't be awakened") Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Link: https://lore.kernel.org/r/20230116205059.3821738-6-shikemeng@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-30sbitmap: add sbitmap_find_bit to remove repeat code in ↵Kemeng Shi1-37/+33
__sbitmap_get/__sbitmap_get_shallow There are three differences between __sbitmap_get and __sbitmap_get_shallow when searching free bit: 1. __sbitmap_get_shallow limit number of bit to search per word. __sbitmap_get has no such limit. 2. __sbitmap_get_shallow always searches with wrap set. __sbitmap_get set wrap according to round_robin. 3. __sbitmap_get_shallow always searches from first bit in first word. __sbitmap_get searches from first bit when round_robin is not set otherwise searches from SB_NR_TO_BIT(sb, alloc_hint). Add helper function sbitmap_find_bit function to do common search while accept "limit depth per word", "wrap flag" and "first bit to search" from caller to support the need of both __sbitmap_get and __sbitmap_get_shallow. Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Link: https://lore.kernel.org/r/20230116205059.3821738-5-shikemeng@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-30sbitmap: rewrite sbitmap_find_bit_in_index to reduce repeat codeKemeng Shi1-15/+15
Rewrite sbitmap_find_bit_in_index as following: 1. Rename sbitmap_find_bit_in_index to sbitmap_find_bit_in_word 2. Accept "struct sbitmap_word *" directly instead of accepting "struct sbitmap *" and "int index" to get "struct sbitmap_word *". 3. Accept depth/shallow_depth and wrap for __sbitmap_get_word from caller to support need of both __sbitmap_get_shallow and __sbitmap_get. With helper function sbitmap_find_bit_in_word, we can remove repeat code in __sbitmap_get_shallow to find bit considring deferred clear. Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Link: https://lore.kernel.org/r/20230116205059.3821738-4-shikemeng@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-30sbitmap: remove redundant check in __sbitmap_queue_get_batchKemeng Shi1-5/+3
Commit fbb564a557809 ("lib/sbitmap: Fix invalid loop in __sbitmap_queue_get_batch()") mentioned that "Checking free bits when setting the target bits. Otherwise, it may reuse the busying bits." This commit add check to make sure all masked bits in word before cmpxchg is zero. Then the existing check after cmpxchg to check any zero bit is existing in masked bits in word is redundant. Actually, old value of word before cmpxchg is stored in val and we will filter out busy bits in val by "(get_mask & ~val)" after cmpxchg. So we will not reuse busy bits methioned in commit fbb564a557809 ("lib/sbitmap: Fix invalid loop in __sbitmap_queue_get_batch()"). Revert new-added check to remove redundant check. Fixes: fbb564a55780 ("lib/sbitmap: Fix invalid loop in __sbitmap_queue_get_batch()") Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Link: https://lore.kernel.org/r/20230116205059.3821738-3-shikemeng@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-30sbitmap: remove unnecessary calculation of alloc_hint in __sbitmap_get_shallowKemeng Shi1-7/+4
Updates to alloc_hint in the loop in __sbitmap_get_shallow() are mostly pointless and equivalent to setting alloc_hint to zero (because SB_NR_TO_BIT() considers only low sb->shift bits from alloc_hint). So simplify the logic. Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Link: https://lore.kernel.org/r/20230116205059.3821738-2-shikemeng@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-30blk-cgroup: synchronize pd_free_fn() from blkg_free_workfn() and ↵Yu Kuai2-6/+30
blkcg_deactivate_policy() Currently parent pd can be freed before child pd: t1: remove cgroup C1 blkcg_destroy_blkgs blkg_destroy list_del_init(&blkg->q_node) // remove blkg from queue list percpu_ref_kill(&blkg->refcnt) blkg_release call_rcu t2: from t1 __blkg_release blkg_free schedule_work t4: deactivate policy blkcg_deactivate_policy pd_free_fn // parent of C1 is freed first t3: from t2 blkg_free_workfn pd_free_fn If policy(for example, ioc_timer_fn() from iocost) access parent pd from child pd after pd_offline_fn(), then UAF can be triggered. Fix the problem by delaying 'list_del_init(&blkg->q_node)' from blkg_destroy() to blkg_free_workfn(), and using a new disk level mutex to synchronize blkg_free_workfn() and blkcg_deactivate_policy(). Signed-off-by: Yu Kuai <yukuai3@huawei.com> Acked-by: Tejun Heo <tj@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20230119110350.2287325-4-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-30blk-cgroup: support to track if policy is onlineYu Kuai2-7/+18
A new field 'online' is added to blkg_policy_data to fix following 2 problem: 1) In blkcg_activate_policy(), if pd_alloc_fn() with 'GFP_NOWAIT' failed, 'queue_lock' will be dropped and pd_alloc_fn() will try again without 'GFP_NOWAIT'. In the meantime, remove cgroup can race with it, and pd_offline_fn() will be called without pd_init_fn() and pd_online_fn(). This way null-ptr-deference can be triggered. 2) In order to synchronize pd_free_fn() from blkg_free_workfn() and blkcg_deactivate_policy(), 'list_del_init(&blkg->q_node)' will be delayed to blkg_free_workfn(), hence pd_offline_fn() can be called first in blkg_destroy(), and then blkcg_deactivate_policy() will call it again, we must prevent it. The new field 'online' will be set after pd_online_fn() and will be cleared after pd_offline_fn(), in the meantime pd_offline_fn() will only be called if 'online' is set. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Acked-by: Tejun Heo <tj@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20230119110350.2287325-3-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-30blk-cgroup: dropping parent refcount after pd_free_fn() is doneYu Kuai1-2/+2
Some cgroup policies will access parent pd through child pd even after pd_offline_fn() is done. If pd_free_fn() for parent is called before child, then UAF can be triggered. Hence it's better to guarantee the order of pd_free_fn(). Currently refcount of parent blkg is dropped in __blkg_release(), which is before pd_free_fn() is called in blkg_free_work_fn() while blkg_free_work_fn() is called asynchronously. This patch make sure pd_free_fn() called from removing cgroup is ordered by delaying dropping parent refcount after calling pd_free_fn() for child. BTW, pd_free_fn() will also be called from blkcg_deactivate_policy() from deleting device, and following patches will guarantee the order. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Acked-by: Tejun Heo <tj@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20230119110350.2287325-2-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-30blk-mq: cleanup unused methods: blk_mq_hw_sysfs_storeZhong Jinghua1-24/+0
We found that the blk_mq_hw_sysfs_store interface has no place to use. The object default_hw_ctx_attrs using blk_mq_hw_sysfs_ops only uses the show method and does not use the store method. Since this patch: 4a46f05ebf99 ("blk-mq: move hctx and ctx counters from sysfs to debugfs") moved the store method to debugfs, the store method is not used anymore. So let me do some tiny work to clean up unused code. Signed-off-by: Zhong Jinghua <zhongjinghua@huawei.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20230128030419.2780298-1-zhongjinghua@huawei.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-30s390/dcssblk:: don't call bio_split_to_limitsChristoph Hellwig1-4/+0
s390 iterates over the bio using bio_for_each_segment and doesn't need any bio splitting. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Link: https://lore.kernel.org/r/20230123075356.60847-1-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-30ps3vram: remove bio splittingChristoph Hellwig1-7/+0
ps3vram iterates over the bio one segment, that is page aligned and max page sized chunk, a time. Because of that there is no point in calling bio_split_to_limits, or explicitly setting the default limits that are only used by bio_split_to_limits. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Geoff Levand <geoff@infradead.org> Link: https://lore.kernel.org/r/20230123074718.57951-1-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-30block: treat poll queue enter similarly to timeoutsJens Axboe1-1/+10
We ran into an issue where a production workload would randomly grind to a halt and not continue until the pending IO had timed out. This turned out to be a complicated interaction between queue freezing and polled IO: 1) You have an application that does polled IO. At any point in time, there may be polled IO pending. 2) You have a monitoring application that issues a passthrough command, which is marked with side effects such that it needs to freeze the queue. 3) Passthrough command is started, which calls blk_freeze_queue_start() on the device. At this point the queue is marked frozen, and any attempt to enter the queue will fail (for non-blocking) or block. 4) Now the driver calls blk_mq_freeze_queue_wait(), which will return when the queue is quiesced and pending IO has completed. 5) The pending IO is polled IO, but any attempt to poll IO through the normal iocb_bio_iopoll() -> bio_poll() will fail when it gets to bio_queue_enter() as the queue is frozen. Rather than poll and complete IO, the polling threads will sit in a tight loop attempting to poll, but failing to enter the queue to do so. The end result is that progress for either application will be stalled until all pending polled IO has timed out. This causes obvious huge latency issues for the application doing polled IO, but also long delays for passthrough command. Fix this by treating queue enter for polled IO just like we do for timeouts. This allows quick quiesce of the queue as we still poll and complete this IO, while still disallowing queueing up new IO. Reviewed-by: Keith Busch <kbusch@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-30blk-iocost: change div64_u64 to DIV64_U64_ROUND_UP in ioc_refresh_params()Li Nan1-2/+2
vrate_min is calculated by DIV64_U64_ROUND_UP, but vrate_max is calculated by div64_u64. Vrate_min may be 1 greater than vrate_max if the input values min and max of cost.qos are equal. Signed-off-by: Li Nan <linan122@huawei.com> Signed-off-by: Yu Kuai <yukuai3@huawei.com> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20230117070806.3857142-6-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-30blk-iocost: fix divide by 0 error in calc_lcoefs()Li Nan1-3/+8
echo max of u64 to cost.model can cause divide by 0 error. # echo 8:0 rbps=18446744073709551615 > /sys/fs/cgroup/io.cost.model divide error: 0000 [#1] PREEMPT SMP RIP: 0010:calc_lcoefs+0x4c/0xc0 Call Trace: <TASK> ioc_refresh_params+0x2b3/0x4f0 ioc_cost_model_write+0x3cb/0x4c0 ? _copy_from_iter+0x6d/0x6c0 ? kernfs_fop_write_iter+0xfc/0x270 cgroup_file_write+0xa0/0x200 kernfs_fop_write_iter+0x17d/0x270 vfs_write+0x414/0x620 ksys_write+0x73/0x160 __x64_sys_write+0x1e/0x30 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd calc_lcoefs() uses the input value of cost.model in DIV_ROUND_UP_ULL, overflow would happen if bps plus IOC_PAGE_SIZE is greater than ULLONG_MAX, it can cause divide by 0 error. Fix the problem by setting basecost Signed-off-by: Li Nan <linan122@huawei.com> Signed-off-by: Yu Kuai <yukuai3@huawei.com> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20230117070806.3857142-5-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-30blk-iocost: read params inside lock in sysfs apisYu Kuai1-0/+4
Otherwise, user might get abnormal values if params is updated concurrently. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20230117070806.3857142-4-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-30blk-iocost: don't allow to configure bio based deviceYu Kuai1-0/+10
iocost is based on rq_qos, which can only work for request based device, thus it doesn't make sense to configure iocost for bio based device. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20230117070806.3857142-3-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-30blk-iocost: check return value of match_u64()Yu Kuai1-1/+2
This patch fixs that the return value of match_u64() from ioc_qos_write() is not checked, Signed-off-by: Yu Kuai <yukuai3@huawei.com> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20230117070806.3857142-2-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-30blk-iocost: avoid 64-bit division in ioc_timer_fnArnd Bergmann1-3/+5
The behavior of 'enum' types has changed in gcc-13, so now the UNBUSY_THR_PCT constant is interpreted as a 64-bit number because it is defined as part of the same enum definition as some other constants that do not fit within a 32-bit integer. This in turn leads to some inefficient code on 32-bit architectures as well as a link error: arm-linux-gnueabi/bin/arm-linux-gnueabi-ld: block/blk-iocost.o: in function `ioc_timer_fn': blk-iocost.c:(.text+0x68e8): undefined reference to `__aeabi_uldivmod' arm-linux-gnueabi-ld: blk-iocost.c:(.text+0x6908): undefined reference to `__aeabi_uldivmod' Split the enum definition to keep the 64-bit timing constants in a separate enum type from those constants that can clearly fit within a smaller type. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20230118080706.3303186-1-arnd@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>