kernel/drivers/md/md.c, branch linux-5.1.y

md: fix for divide error in status_resync

2019-07-14T06:09:45Z

[ Upstream commit 9642fa73d073527b0cbc337cc17a47d545d82cd2 ] Stopping external metadata arrays during resync/recovery causes retries, loop of interrupting and starting reconstruction, until it hit at good moment to stop completely. While these retries curr_mark_cnt can be small- especially on HDD drives, so subtraction result can be smaller than 0. However it is casted to uint without checking. As a result of it the status bar in /proc/mdstat while stopping is strange (it jumps between 0% and 99%). The real problem occurs here after commit 72deb455b5ec ("block: remove CONFIG_LBDAF"). Sector_div() macro has been changed, now the divisor is casted to uint32. For db = -8 the divisior(db/32-1) becomes 0. Check if db value can be really counted and replace these macro by div64_u64() inline. Signed-off-by: Mariusz Tkaczyk Signed-off-by: Song Liu Signed-off-by: Sasha Levin

md: add a missing endianness conversion in check_sb_changes

2019-05-25T16:16:24Z

commit ed4d0a4ea11e19863952ac6a7cea3bbb27ccd452 upstream. The on-disk value is little endian and we need to convert it to native endian before storing the value in the in-core structure. Fixes: 7564beda19b36 ("md-cluster/raid10: support add disk under grow mode") Cc: # 4.20+ Acked-by: Guoqing Jiang Signed-off-by: Christoph Hellwig Signed-off-by: Song Liu Signed-off-by: Greg Kroah-Hartman

md: add mddev->pers to avoid potential NULL pointer dereference

2019-05-25T16:16:24Z

commit ee37e62191a59d253fc916b9fc763deb777211e2 upstream. When doing re-add, we need to ensure rdev->mddev->pers is not NULL, which can avoid potential NULL pointer derefence in fallowing add_bound_rdev(). Fixes: a6da4ef85cef ("md: re-add a failed disk") Cc: Xiao Ni Cc: NeilBrown Cc: # 4.4+ Reviewed-by: NeilBrown Signed-off-by: Yufen Yu Signed-off-by: Song Liu Signed-off-by: Greg Kroah-Hartman

md: batch flush requests.

2019-05-25T16:16:23Z

commit 2bc13b83e6298486371761de503faeffd15b7534 upstream. Currently if many flush requests are submitted to an md device is quick succession, they are serialized and can take a long to process them all. We don't really need to call flush all those times - a single flush call can satisfy all requests submitted before it started. So keep track of when the current flush started and when it finished, allow any pending flush that was requested before the flush started to complete without waiting any more. Test results from Xiao: Test is done on a raid10 device which is created by 4 SSDs. The tool is dbench. 1. The latest linux stable kernel Operation Count AvgLat MaxLat -------------------------------------------------- Deltree 768 10.509 78.305 Flush 2078376 0.013 10.094 Close 21787697 0.019 18.821 LockX 96580 0.007 3.184 Mkdir 384 0.008 0.062 Rename 1255883 0.191 23.534 ReadX 46495589 0.020 14.230 WriteX 14790591 7.123 60.706 Unlink 5989118 0.440 54.551 UnlockX 96580 0.005 2.736 FIND_FIRST 10393845 0.042 12.079 SET_FILE_INFORMATION 2415558 0.129 10.088 QUERY_FILE_INFORMATION 4711725 0.005 8.462 QUERY_PATH_INFORMATION 26883327 0.032 21.715 QUERY_FS_INFORMATION 4929409 0.010 8.238 NTCreateX 29660080 0.100 53.268 Throughput 1034.88 MB/sec (sync open) 128 clients 128 procs max_latency=60.712 ms 2. With patch1 "Revert "MD: fix lock contention for flush bios"" Operation Count AvgLat MaxLat -------------------------------------------------- Deltree 256 8.326 36.761 Flush 693291 3.974 180.269 Close 7266404 0.009 36.929 LockX 32160 0.006 0.840 Mkdir 128 0.008 0.021 Rename 418755 0.063 29.945 ReadX 15498708 0.007 7.216 WriteX 4932310 22.482 267.928 Unlink 1997557 0.109 47.553 UnlockX 32160 0.004 1.110 FIND_FIRST 3465791 0.036 7.320 SET_FILE_INFORMATION 805825 0.015 1.561 QUERY_FILE_INFORMATION 1570950 0.005 2.403 QUERY_PATH_INFORMATION 8965483 0.013 14.277 QUERY_FS_INFORMATION 1643626 0.009 3.314 NTCreateX 9892174 0.061 41.278 Throughput 345.009 MB/sec (sync open) 128 clients 128 procs max_latency=267.939 m 3. With patch1 and patch2 Operation Count AvgLat MaxLat -------------------------------------------------- Deltree 768 9.570 54.588 Flush 2061354 0.666 15.102 Close 21604811 0.012 25.697 LockX 95770 0.007 1.424 Mkdir 384 0.008 0.053 Rename 1245411 0.096 12.263 ReadX 46103198 0.011 12.116 WriteX 14667988 7.375 60.069 Unlink 5938936 0.173 30.905 UnlockX 95770 0.005 4.147 FIND_FIRST 10306407 0.041 11.715 SET_FILE_INFORMATION 2395987 0.048 7.640 QUERY_FILE_INFORMATION 4672371 0.005 9.291 QUERY_PATH_INFORMATION 26656735 0.018 19.719 QUERY_FS_INFORMATION 4887940 0.010 7.654 NTCreateX 29410811 0.059 28.551 Throughput 1026.21 MB/sec (sync open) 128 clients 128 procs max_latency=60.075 ms Cc: # v4.19+ Tested-by: Xiao Ni Signed-off-by: NeilBrown Signed-off-by: Song Liu Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

Revert "MD: fix lock contention for flush bios"

2019-05-25T16:16:23Z

commit 4bc034d35377196c854236133b07730a777c4aba upstream. This reverts commit 5a409b4f56d50b212334f338cb8465d65550cd85. This patch has two problems. 1/ it make multiple calls to submit_bio() from inside a make_request_fn. The bios thus submitted will be queued on current->bio_list and not submitted immediately. As the bios are allocated from a mempool, this can theoretically result in a deadlock - all the pool of requests could be in various ->bio_list queues and a subsequent mempool_alloc could block waiting for one of them to be released. 2/ It aims to handle a case when there are many concurrent flush requests. It handles this by submitting many requests in parallel - all of which are identical and so most of which do nothing useful. It would be more efficient to just send one lower-level request, but allow that to satisfy multiple upper-level requests. Fixes: 5a409b4f56d5 ("MD: fix lock contention for flush bios") Cc: # v4.19+ Tested-by: Xiao Ni Signed-off-by: NeilBrown Signed-off-by: Song Liu Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

md: Make bio_alloc_mddev use bio_alloc_bioset

2019-01-14T13:31:56Z

bio_alloc_bioset returns a bio pointer or NULL, so we can avoid storing the returned data into a new variable. Acked-by: Guoqing Jiang Acked-by: Artur Paszkiewicz Signed-off-by: Marcos Paulo de Souza Signed-off-by: Jens Axboe

Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md into for-linus

2019-01-03T15:21:02Z

Pull the pending 4.21 changes for md from Shaohua. * 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md: md: fix raid10 hang issue caused by barrier raid10: refactor common wait code from regular read/write request md: remvoe redundant condition check lib/raid6: add option to skip algo benchmarking lib/raid6: sort algos in rough performance order lib/raid6: check for assembler SSSE3 support lib/raid6: avoid __attribute_const__ redefinition lib/raid6: add missing include for raid6test md: remove set but not used variable 'bi_rdev'

md: remvoe redundant condition check

2018-12-20T16:53:24Z

mempool_destroy() can handle NULL pointer correctly, so there is no need to check NULL pointer before calling mempool_destroy(). Signed-off-by: Chengguang Xu Signed-off-by: Shaohua Li

md: remove set but not used variable 'bi_rdev'

2018-12-20T16:53:23Z

Fixes gcc '-Wunused-but-set-variable' warning: drivers/md/md.c: In function 'md_integrity_add_rdev': drivers/md/md.c:2149:24: warning: variable 'bi_rdev' set but not used [-Wunused-but-set-variable] It not used any more after commit 1501efadc524 ("md/raid: only permit hot-add of compatible integrity profiles") Signed-off-by: Yue Haibing Signed-off-by: Shaohua Li

block: stop passing 'cpu' to all percpu stats methods

2018-12-10T15:30:37Z

All of part_stat_* and related methods are used with preempt disabled, so there is no need to pass cpu around to allow of them. Just call smp_processor_id() as needed. Suggested-by: Jens Axboe Signed-off-by: Mike Snitzer Signed-off-by: Jens Axboe