kernel/linux.git/drivers/md/bcache/sysfs.c, branch v5.6.17

bcache: add readahead cache policy options via sysfs interface

2020-02-01T14:55:39+00:00

In year 2007 high performance SSD was still expensive, in order to save more space for real workload or meta data, the readahead I/Os for non-meta data was bypassed and not cached on SSD. In now days, SSD price drops a lot and people can find larger size SSD with more comfortable price. It is unncessary to alway bypass normal readahead I/Os to save SSD space for now. This patch adds options for readahead data cache policies via sysfs file /sys/block/bcache/readahead_cache_policy, the options are, - "all": cache all readahead data I/Os. - "meta-only": only cache meta data, and bypass other regular I/Os. If users want to make bcache continue to only cache readahead request for metadata and bypass regular data readahead, please set "meta-only" to this sysfs file. By default, bcache will back to cache all read- ahead requests now. Cc: stable@vger.kernel.org Signed-off-by: Coly Li Acked-by: Eric Wheeler Cc: Michael Lyle Signed-off-by: Jens Axboe

bcache: add idle_max_writeback_rate sysfs interface

2019-11-13T22:42:50+00:00

For writeback mode, if there is no regular I/O request for a while, the writeback rate will be set to the maximum value (1TB/s for now). This is good for most of the storage workload, but there are still people don't what the maximum writeback rate in I/O idle time. This patch adds a sysfs interface file idle_max_writeback_rate to permit people to disable maximum writeback rate. Then the minimum writeback rate can be advised by writeback_rate_minimum in the bcache device's sysfs interface. Reported-by: Christian Balzer Signed-off-by: Coly Li Signed-off-by: Jens Axboe

Merge tag 'for-5.4/block-2019-09-16' of git://git.kernel.dk/linux-block

2019-09-17T23:57:47+00:00

Pull block updates from Jens Axboe: - Two NVMe pull requests: - ana log parse fix from Anton - nvme quirks support for Apple devices from Ben - fix missing bio completion tracing for multipath stack devices from Hannes and Mikhail - IP TOS settings for nvme rdma and tcp transports from Israel - rq_dma_dir cleanups from Israel - tracing for Get LBA Status command from Minwoo - Some nvme-tcp cleanups from Minwoo, Potnuri and Myself - Some consolidation between the fabrics transports for handling the CAP register - reset race with ns scanning fix for fabrics (move fabrics commands to a dedicated request queue with a different lifetime from the admin request queue)." - controller reset and namespace scan races fixes - nvme discovery log change uevent support - naming improvements from Keith - multiple discovery controllers reject fix from James - some regular cleanups from various people - Series fixing (and re-fixing) null_blk debug printing and nr_devices checks (André) - A few pull requests from Song, with fixes from Andy, Guoqing, Guilherme, Neil, Nigel, and Yufen. - REQ_OP_ZONE_RESET_ALL support (Chaitanya) - Bio merge handling unification (Christoph) - Pick default elevator correctly for devices with special needs (Damien) - Block stats fixes (Hou) - Timeout and support devices nbd fixes (Mike) - Series fixing races around elevator switching and device add/remove (Ming) - sed-opal cleanups (Revanth) - Per device weight support for BFQ (Fam) - Support for blk-iocost, a new model that can properly account cost of IO workloads. (Tejun) - blk-cgroup writeback fixes (Tejun) - paride queue init fixes (zhengbin) - blk_set_runtime_active() cleanup (Stanley) - Block segment mapping optimizations (Bart) - lightnvm fixes (Hans/Minwoo/YueHaibing) - Various little fixes and cleanups * tag 'for-5.4/block-2019-09-16' of git://git.kernel.dk/linux-block: (186 commits) null_blk: format pr_* logs with pr_fmt null_blk: match the type of parameter nr_devices null_blk: do not fail the module load with zero devices block: also check RQF_STATS in blk_mq_need_time_stamp() block: make rq sector size accessible for block stats bfq: Fix bfq linkage error raid5: use bio_end_sector in r5_next_bio raid5: remove STRIPE_OPS_REQ_PENDING md: add feature flag MD_FEATURE_RAID0_LAYOUT md/raid0: avoid RAID0 data corruption due to layout confusion. raid5: don't set STRIPE_HANDLE to stripe which is in batch list raid5: don't increment read_errors on EILSEQ return nvmet: fix a wrong error status returned in error log page nvme: send discovery log page change events to userspace nvme: add uevent variables for controller devices nvme: enable aen regardless of the presence of I/O queues nvme-fabrics: allow discovery subsystems accept a kato nvmet: Use PTR_ERR_OR_ZERO() in nvmet_init_discovery() nvme: Remove redundant assignment of cq vector nvme: Assign subsys instance from first ctrl ...

bcache: add cond_resched() in __bch_cache_cmp()

2019-09-03T14:08:28+00:00

Read /sys/fs/bcache//cacheN/priority_stats can take very long time with huge cache after long run. Signed-off-by: Shile Zhang Tested-by: Heitor Alves de Siqueira Signed-off-by: Coly Li Signed-off-by: Jens Axboe

bcache: Revert "bcache: use sysfs_match_string() instead of __sysfs_match_string()"

2019-08-09T13:37:33+00:00

This reverts commit 89e0341af082dbc170019f908846f4a424efc86b. In drivers/md/bcache/sysfs.c:bch_snprint_string_list(), NULL pointer at the end of list is necessary. Remove the NULL from last element of each lists will cause the following panic, [ 4340.455652] bcache: register_cache() registered cache device nvme0n1 [ 4340.464603] bcache: register_bdev() registered backing device sdk [ 4421.587335] bcache: bch_cached_dev_run() cached dev sdk is running already [ 4421.587348] bcache: bch_cached_dev_attach() Caching sdk as bcache0 on set 354e1d46-d99f-4d8b-870b-078b80dc88a6 [ 5139.247950] general protection fault: 0000 [#1] SMP NOPTI [ 5139.247970] CPU: 9 PID: 5896 Comm: cat Not tainted 4.12.14-95.29-default #1 SLE12-SP4 [ 5139.247988] Hardware name: HPE ProLiant DL380 Gen10/ProLiant DL380 Gen10, BIOS U30 04/18/2019 [ 5139.248006] task: ffff888fb25c0b00 task.stack: ffff9bbacc704000 [ 5139.248021] RIP: 0010:string+0x21/0x70 [ 5139.248030] RSP: 0018:ffff9bbacc707bf0 EFLAGS: 00010286 [ 5139.248043] RAX: ffffffffa7e432e3 RBX: ffff8881c20da02a RCX: ffff0a00ffffff04 [ 5139.248058] RDX: 3f00656863616362 RSI: ffff8881c20db000 RDI: ffffffffffffffff [ 5139.248075] RBP: ffff8881c20db000 R08: 0000000000000000 R09: ffff8881c20da02a [ 5139.248090] R10: 0000000000000004 R11: 0000000000000000 R12: ffff9bbacc707c48 [ 5139.248104] R13: 0000000000000fd6 R14: ffffffffc0665855 R15: ffffffffc0665855 [ 5139.248119] FS: 00007faf253b8700(0000) GS:ffff88903f840000(0000) knlGS:0000000000000000 [ 5139.248137] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 5139.248149] CR2: 00007faf25395008 CR3: 0000000f72150006 CR4: 00000000007606e0 [ 5139.248164] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 5139.248179] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 5139.248193] PKRU: 55555554 [ 5139.248200] Call Trace: [ 5139.248210] vsnprintf+0x1fb/0x510 [ 5139.248221] snprintf+0x39/0x40 [ 5139.248238] bch_snprint_string_list.constprop.15+0x5b/0x90 [bcache] [ 5139.248256] __bch_cached_dev_show+0x44d/0x5f0 [bcache] [ 5139.248270] ? __alloc_pages_nodemask+0xb2/0x210 [ 5139.248284] bch_cached_dev_show+0x2c/0x50 [bcache] [ 5139.248297] sysfs_kf_seq_show+0xbb/0x190 [ 5139.248308] seq_read+0xfc/0x3c0 [ 5139.248317] __vfs_read+0x26/0x140 [ 5139.248327] vfs_read+0x87/0x130 [ 5139.248336] SyS_read+0x42/0x90 [ 5139.248346] do_syscall_64+0x74/0x160 [ 5139.248358] entry_SYSCALL_64_after_hwframe+0x3d/0xa2 [ 5139.248370] RIP: 0033:0x7faf24eea370 [ 5139.248379] RSP: 002b:00007fff82d03f38 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 5139.248395] RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007faf24eea370 [ 5139.248411] RDX: 0000000000020000 RSI: 00007faf25396000 RDI: 0000000000000003 [ 5139.248426] RBP: 00007faf25396000 R08: 00000000ffffffff R09: 0000000000000000 [ 5139.248441] R10: 000000007c9d4d41 R11: 0000000000000246 R12: 00007faf25396000 [ 5139.248456] R13: 0000000000000003 R14: 0000000000000000 R15: 0000000000000fff [ 5139.248892] Code: ff ff ff 0f 1f 80 00 00 00 00 49 89 f9 48 89 cf 48 c7 c0 e3 32 e4 a7 48 c1 ff 30 48 81 fa ff 0f 00 00 48 0f 46 d0 48 85 ff 74 45 <44> 0f b6 02 48 8d 42 01 45 84 c0 74 38 48 01 fa 4c 89 cf eb 0e The simplest way to fix is to revert commit 89e0341af082 ("bcache: use sysfs_match_string() instead of __sysfs_match_string()"). This bug was introduced in Linux v5.2, so this fix only applies to Linux v5.2 is enough for stable tree maintainer. Fixes: 89e0341af082 ("bcache: use sysfs_match_string() instead of __sysfs_match_string()") Cc: stable@vger.kernel.org Cc: Alexandru Ardelean Reported-by: Peifeng Lin Acked-by: Alexandru Ardelean Signed-off-by: Coly Li Signed-off-by: Jens Axboe

bcache: add reclaimed_journal_buckets to struct cache_set

2019-06-28T13:39:18+00:00

Now we have counters for how many times jouranl is reclaimed, how many times cached dirty btree nodes are flushed, but we don't know how many jouranl buckets are really reclaimed. This patch adds reclaimed_journal_buckets into struct cache_set, this is an increasing only counter, to tell how many journal buckets are reclaimed since cache set runs. From all these three counters (reclaim, reclaimed_journal_buckets, flush_write), we can have idea how well current journal space reclaim code works. Signed-off-by: Coly Li Signed-off-by: Jens Axboe

bcache: remove retry_flush_write from struct cache_set

2019-06-28T13:39:18+00:00

In struct cache_set, retry_flush_write is added for commit c4dc2497d50d ("bcache: fix high CPU occupancy during journal") which is reverted in previous patch. Now it is useless anymore, and this patch removes it from bcache code. Signed-off-by: Coly Li Signed-off-by: Jens Axboe

bcache: avoid a deadlock in bcache_reboot()

2019-06-28T13:39:16+00:00

It is quite frequently to observe deadlock in bcache_reboot() happens and hang the system reboot process. The reason is, in bcache_reboot() when calling bch_cache_set_stop() and bcache_device_stop() the mutex bch_register_lock is held. But in the process to stop cache set and bcache device, bch_register_lock will be acquired again. If this mutex is held here, deadlock will happen inside the stopping process. The aftermath of the deadlock is, whole system reboot gets hung. The fix is to avoid holding bch_register_lock for the following loops in bcache_reboot(), list_for_each_entry_safe(c, tc, &bch_cache_sets, list) bch_cache_set_stop(c); list_for_each_entry_safe(dc, tdc, &uncached_devices, list) bcache_device_stop(&dc->disk); A module range variable 'bcache_is_reboot' is added, it sets to true in bcache_reboot(). In register_bcache(), if bcache_is_reboot is checked to be true, reject the registration by returning -EBUSY immediately. Signed-off-by: Coly Li Signed-off-by: Jens Axboe

bcache: fix mistaken sysfs entry for io_error counter

2019-06-28T13:39:16+00:00

In bch_cached_dev_files[] from driver/md/bcache/sysfs.c, sysfs_errors is incorrectly inserted in. The correct entry should be sysfs_io_errors. This patch fixes the problem and now I/O errors of cached device can be read from /sys/block/bcache/bcache/io_errors. Fixes: c7b7bd07404c5 ("bcache: add io_disable to struct cached_dev") Signed-off-by: Coly Li Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe

bcache: add return value check to bch_cached_dev_run()

2019-06-28T13:39:14+00:00

This patch adds return value check to bch_cached_dev_run(), now if there is error happens inside bch_cached_dev_run(), it can be catched. Signed-off-by: Coly Li Signed-off-by: Jens Axboe