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* md/r5cache: disable write back for degraded arraySong Liu2017-01-243-7/+56
| | | | | | | | | | | | | | | | | | write-back cache in degraded mode introduces corner cases to the array. Although we try to cover all these corner cases, it is safer to just disable write-back cache when the array is in degraded mode. In this patch, we disable writeback cache for degraded mode: 1. On device failure, if the array enters degraded mode, raid5_error() will submit async job r5c_disable_writeback_async to disable writeback; 2. In r5c_journal_mode_store(), it is invalid to enable writeback in degraded mode; 3. In r5c_try_caching_write(), stripes with s->failed>0 will be handled in write-through mode. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com>
* md/r5cache: shift complex rmw from read path to write pathSong Liu2017-01-241-4/+45
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Write back cache requires a complex RMW mechanism, where old data is read into dev->orig_page for prexor, and then xor is done with dev->page. This logic is already implemented in the write path. However, current read path is not awared of this requirement. When the array is optimal, the RMW is not required, as the data are read from raid disks. However, when the target stripe is degraded, complex RMW is required to generate right data. To keep read path as clean as possible, we handle read path by flushing degraded, in-journal stripes before processing reads to missing dev. Specifically, when there is read requests to a degraded stripe with data in journal, handle_stripe_fill() calls r5c_make_stripe_write_out() and exits. Then handle_stripe_dirtying() will do the complex RMW and flush the stripe to RAID disks. After that, read requests are handled. There is one more corner case when there is non-overwrite bio for the missing (or out of sync) dev. handle_stripe_dirtying() will not be able to process the non-overwrite bios without constructing the data in handle_stripe_fill(). This is fixed by delaying non-overwrite bios in handle_stripe_dirtying(). So handle_stripe_fill() works on these bios after the stripe is flushed to raid disks. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com>
* md/r5cache: flush data only stripes in r5l_recovery_log()Song Liu2017-01-242-16/+45
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | For safer operation, all arrays start in write-through mode, which has been better tested and is more mature. And actually the write-through/write-mode isn't persistent after array restarted, so we always start array in write-through mode. However, if recovery found data-only stripes before the shutdown (from previous write-back mode), it is not safe to start the array in write-through mode, as write-through mode can not handle stripes with data in write-back cache. To solve this problem, we flush all data-only stripes in r5l_recovery_log(). When r5l_recovery_log() returns, the array starts with empty cache in write-through mode. This logic is implemented in r5c_recovery_flush_data_only_stripes(): 1. enable write back cache 2. flush all stripes 3. wake up conf->mddev->thread 4. wait for all stripes get flushed (reuse wait_for_quiescent) 5. disable write back cache The wait in 4 will be waked up in release_inactive_stripe_list() when conf->active_stripes reaches 0. It is safe to wake up mddev->thread here because all the resource required for the thread has been initialized. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com>
* md/raid5: move comment of fetch_block to right locationSong Liu2017-01-241-7/+6
| | | | | Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com>
* md/r5cache: read data into orig_page for prexor of cached dataSong Liu2017-01-243-9/+42
| | | | | | | | | | | | | | With write back cache, we use orig_page to do prexor. This patch makes sure we read data into orig_page for it. Flag R5_OrigPageUPTDODATE is added to show whether orig_page has the latest data from raid disk. We introduce a helper function uptodate_for_rmw() to simplify the a couple conditions in handle_stripe_dirtying(). Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com>
* md/raid5-cache: delete meaningless codeShaohua Li2017-01-241-2/+0
| | | | | | | sector_t is unsigned long, it's never < 0 Reported-by: Julia Lawall <julia.lawall@lip6.fr> Signed-off-by: Shaohua Li <shli@fb.com>
* md/raid5: Use correct IS_ERR() variation on pointer checkJes Sorensen2017-01-091-1/+1
| | | | | | | | This fixes a build error on certain architectures, such as ppc64. Fixes: 6995f0b247e("md: takeover should clear unrelated bits") Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com> Signed-off-by: Shaohua Li <shli@fb.com>
* md: cleanup mddev flag clear for takeoverShaohua Li2017-01-054-7/+26
| | | | | | | | | | Commit 6995f0b (md: takeover should clear unrelated bits) clear unrelated bits, but it's quite fragile. To avoid error in the future, define a macro for unsupported mddev flags for each raid type and use it to clear unsupported mddev flags. This should be less error-prone. Suggested-by: NeilBrown <neilb@suse.com> Signed-off-by: Shaohua Li <shli@fb.com>
* md/r5cache: fix spelling mistake on "recoverying"Colin Ian King2017-01-051-1/+1
| | | | | | | | Trivial fix to spelling mistake "recoverying" to "recovering" in pr_dbg message. Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Shaohua Li <shli@fb.com>
* md/r5cache: assign conf->log before r5l_load_log()Song Liu2017-01-051-1/+3
| | | | | | | | | | r5l_load_log() calls functions that requires a proper conf->log, for example, r5c_is_writeback(). Therefore, we should set conf->log before calling r5l_load_log(). If r5l_load_log() fails, conf->log is set back to NULL. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com>
* md/r5cache: simplify handling of sh->log_start in recoverySong Liu2017-01-051-15/+12
| | | | | | | | | | | | | We only need to update sh->log_start at the end of recovery, which is r5c_recovery_rewrite_data_only_stripes(), so it is not necessary to set it before that. In this patch, log_start is removed from r5c_recovery_alloc_stripe(). After updating all sh->log_start, rewrite_data_only_stripes() also updates log->next_checkpoints to the last sh->log_start. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com>
* md/raid5-cache: removes unnecessary write-through mode judgmentsJackieLiu2017-01-051-3/+0
| | | | | | | | | The write-through mode has been returned in front of the function, do not need to do it again. Signed-off-by: JackieLiu <liuyun01@kylinos.cn> Reviewed-by: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com>
* md/raid10: Refactor raid10_make_requestRobert LeBlanc2017-01-031-105/+140
| | | | | | | | | | Refactor raid10_make_request into seperate read and write functions to clean up the code. Shaohua: add the recovery check back to read path Signed-off-by: Robert LeBlanc <robert@leblancnet.us> Signed-off-by: Shaohua Li <shli@fb.com>
* md/raid1: Refactor raid1_make_requestRobert LeBlanc2017-01-031-128/+139
| | | | | | | | Refactor raid1_make_request to make read and write code in their own functions to clean up the code. Signed-off-by: Robert LeBlanc <robert@leblancnet.us> Signed-off-by: Shaohua Li <shli@fb.com>
* Replace <asm/uaccess.h> with <linux/uaccess.h> globallyLinus Torvalds2016-12-241-1/+1
| | | | | | | | | | | | | This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>' sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* bcache: partition support: add 16 minors per bcacheN deviceEric Wheeler2016-12-171-1/+4
| | | | | Signed-off-by: Eric Wheeler <bcache@linux.ewheeler.net> Tested-by: Wido den Hollander <wido@widodh.nl>
* bcache: Make gc wakeup sane, remove set_task_state()Kent Overstreet2016-12-175-26/+26
| | | | Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
* linux: drop __bitwise__ everywhereMichael S. Tsirkin2016-12-161-3/+3
| | | | | | | | | | | | | __bitwise__ used to mean "yes, please enable sparse checks unconditionally", but now that we dropped __CHECK_ENDIAN__ __bitwise is exactly the same. There aren't many users, replace it by __bitwise everywhere. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Stefan Schmidt <stefan@osg.samsung.com> Acked-by: Krzysztof Kozlowski <krzk@kernel.org> Akced-by: Lee Duncan <lduncan@suse.com>
* Merge tag 'dm-4.10-changes' of ↵Linus Torvalds2016-12-1419-173/+406
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper updates from Mike Snitzer: - various fixes and improvements to request-based DM and DM multipath - some locking improvements in DM bufio - add Kconfig option to disable the DM block manager's extra locking which mainly serves as a developer tool - a few bug fixes to DM's persistent-data - a couple changes to prepare for multipage biovec support in the block layer - various improvements and cleanups in the DM core, DM cache, DM raid and DM crypt - add ability to have DM crypt use keys from the kernel key retention service - add a new "error_writes" feature to the DM flakey target, reads are left unchanged in this mode * tag 'dm-4.10-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (40 commits) dm flakey: introduce "error_writes" feature dm cache policy smq: use hash_32() instead of hash_32_generic() dm crypt: reject key strings containing whitespace chars dm space map: always set ev if sm_ll_mutate() succeeds dm space map metadata: skip useless memcpy in metadata_ll_init_index() dm space map metadata: fix 'struct sm_metadata' leak on failed create Documentation: dm raid: define data_offset status field dm raid: fix discard support regression dm raid: don't allow "write behind" with raid4/5/6 dm mpath: use hw_handler_params if attached hw_handler is same as requested dm crypt: add ability to use keys from the kernel key retention service dm array: remove a dead assignment in populate_ablock_with_values() dm ioctl: use offsetof() instead of open-coding it dm rq: simplify use_blk_mq initialization dm: use blk_set_queue_dying() in __dm_destroy() dm bufio: drop the lock when doing GFP_NOIO allocation dm bufio: don't take the lock in dm_bufio_shrink_count dm bufio: avoid sleeping while holding the dm_bufio lock dm table: simplify dm_table_determine_type() dm table: an 'all_blk_mq' table must be loaded for a blk-mq DM device ...
| * dm flakey: introduce "error_writes" featureMike Snitzer2016-12-131-9/+42
| | | | | | | | | | | | | | | | | | | | | | Recent dm-flakey fixes, to have reads error out during the "down" interval, made it so that the previous read behaviour is no longer available. It is useful to have reads complete like normal but have writes error out, so make it possible again with a new "error_writes" feature. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * dm cache policy smq: use hash_32() instead of hash_32_generic()Mike Snitzer2016-12-081-1/+1
| | | | | | | | | | | | | | Switch to using hash_32() because hash_32_generic() should only be used by the kernel's selftests. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * dm crypt: reject key strings containing whitespace charsOndrej Kozina2016-12-081-0/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Unfortunately key_string may theoretically contain whitespace even after it's processed by dm_split_args(). The reason for this is DM core supports escaping of almost all chars including any whitespace. If userspace passes a key to the kernel in format ":32:logon:my_prefix:my\ key" dm-crypt will look up key "my_prefix:my key" in kernel keyring service. So far everything's fine. Unfortunately if userspace later calls DM_TABLE_STATUS ioctl, it will not receive back expected ":32:logon:my_prefix:my\ key" but the unescaped version instead. Also userpace (most notably cryptsetup) is not ready to parse single target argument containing (even escaped) whitespace chars and any whitespace is simply taken as delimiter of another argument. This effect is mitigated by the fact libdevmapper curently performs double escaping of '\' char. Any user input in format "x\ x" is transformed into "x\\ x" before being passed to the kernel. Nonetheless dm-crypt may be used without libdevmapper. Therefore the near-term solution to this is to reject any key string containing whitespace. Signed-off-by: Ondrej Kozina <okozina@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * dm space map: always set ev if sm_ll_mutate() succeedsBenjamin Marzinski2016-12-081-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If no block was allocated or freed, sm_ll_mutate() wasn't setting *ev, leaving the variable unitialized. sm_ll_insert(), sm_disk_inc_block(), and sm_disk_new_block() all check ev to see if there was an allocation event in sm_ll_mutate(), possibly reading unitialized data. If no allocation event occured, sm_ll_mutate() should set *ev to SM_NONE. Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * dm space map metadata: skip useless memcpy in metadata_ll_init_index()Benjamin Marzinski2016-12-081-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | When metadata_ll_init_index() is called by sm_ll_new_metadata(), ll->mi_le hasn't been initialized yet. So, when metadata_ll_init_index() copies the contents of ll->mi_le into the newly allocated bitmap_root, it is just copying garbage. ll->mi_le will be allocated later in sm_ll_extend() and copied into the bitmap_root, in sm_ll_commit(). Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * dm space map metadata: fix 'struct sm_metadata' leak on failed createBenjamin Marzinski2016-12-081-8/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In dm_sm_metadata_create() we temporarily change the dm_space_map operations from 'ops' (whose .destroy function deallocates the sm_metadata) to 'bootstrap_ops' (whose .destroy function doesn't). If dm_sm_metadata_create() fails in sm_ll_new_metadata() or sm_ll_extend(), it exits back to dm_tm_create_internal(), which calls dm_sm_destroy() with the intention of freeing the sm_metadata, but it doesn't (because the dm_space_map operations is still set to 'bootstrap_ops'). Fix this by setting the dm_space_map operations back to 'ops' if dm_sm_metadata_create() fails when it is set to 'bootstrap_ops'. Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
| * dm raid: fix discard support regressionHeinz Mauelshagen2016-12-081-6/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit ecbfb9f118 ("dm raid: add raid level takeover support") moved the configure_discard_support() call from raid_ctr() to raid_preresume(). Enabling/disabling discard _must_ happen during table load (through the .ctr hook). Fix this regression by moving the configure_discard_support() call back to raid_ctr(). Fixes: ecbfb9f118 ("dm raid: add raid level takeover support") Cc: stable@vger.kernel.org # 4.8+ Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * dm raid: don't allow "write behind" with raid4/5/6Heinz Mauelshagen2016-12-081-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove CTR_FLAG_MAX_WRITE_BEHIND from raid4/5/6's valid ctr flags. Only the md raid1 personality supports setting a maximum number of "write behind" write IOs on any legs set to "write mostly". "write mostly" enhances throughput with slow links/disks. Technically the "write behind" value is a write intent bitmap property only being respected by the raid1 personality. It allows a maximum number of "write behind" writes to any "write mostly" raid1 mirror legs to be delayed and avoids reads from such legs. No other MD personalities supported via dm-raid make use of "write behind", thus setting this property is superfluous; it wouldn't cause harm but it is correct to reject it. Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * dm mpath: use hw_handler_params if attached hw_handler is same as requestedtang.junhui2016-12-081-5/+9
| | | | | | | | | | | | | | | | Let the requested m->hw_handler_params be used if the attached hardware handler is the same handler as requested with m->hw_handler_name. Signed-off-by: tang.junhui <tang.junhui@zte.com.cn> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * dm crypt: add ability to use keys from the kernel key retention serviceOndrej Kozina2016-12-081-13/+146
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The kernel key service is a generic way to store keys for the use of other subsystems. Currently there is no way to use kernel keys in dm-crypt. This patch aims to fix that. Instead of key userspace may pass a key description with preceding ':'. So message that constructs encryption mapping now looks like this: <cipher> [<key>|:<key_string>] <iv_offset> <dev_path> <start> [<#opt_params> <opt_params>] where <key_string> is in format: <key_size>:<key_type>:<key_description> Currently we only support two elementary key types: 'user' and 'logon'. Keys may be loaded in dm-crypt either via <key_string> or using classical method and pass the key in hex representation directly. dm-crypt device initialised with a key passed in hex representation may be replaced with key passed in key_string format and vice versa. (Based on original work by Andrey Ryabinin) Signed-off-by: Ondrej Kozina <okozina@redhat.com> Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * dm array: remove a dead assignment in populate_ablock_with_values()Bart Van Assche2016-12-081-2/+0
| | | | | | | | | | | | | | A value is assigned to 'nr_entries' but is never used, remove it. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * dm ioctl: use offsetof() instead of open-coding itBart Van Assche2016-12-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | Subtracting sizes is a fragile approach because the result is only correct if the compiler has not added any padding at the end of the structure. Hence use offsetof() instead of size subtraction. An additional advantage of offsetof() is that it makes the intent more clear. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * dm rq: simplify use_blk_mq initializationBart Van Assche2016-12-081-5/+1
| | | | | | | | | | | | | | | | Use a single statement to declare and initialize 'use_blk_mq' instead of two statements. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * dm: use blk_set_queue_dying() in __dm_destroy()Bart Van Assche2016-12-081-3/+1
| | | | | | | | | | | | | | | | | | | | After QUEUE_FLAG_DYING has been set any code that is waiting in get_request() should be woken up. But to get this behaviour blk_set_queue_dying() must be used instead of only setting QUEUE_FLAG_DYING. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * dm bufio: drop the lock when doing GFP_NOIO allocationMikulas Patocka2016-12-081-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | If the first allocation attempt using GFP_NOWAIT fails, drop the lock and retry using GFP_NOIO allocation (lock is dropped because the allocation can take some time). Note that we won't do GFP_NOIO allocation when we loop for the second time, because the lock shouldn't be dropped between __wait_for_free_buffer and __get_unclaimed_buffer. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * dm bufio: don't take the lock in dm_bufio_shrink_countMikulas Patocka2016-12-081-11/+2
| | | | | | | | | | | | | | | | | | | | dm_bufio_shrink_count() is called from do_shrink_slab to find out how many freeable objects are there. The reported value doesn't have to be precise, so we don't need to take the dm-bufio lock. Suggested-by: David Rientjes <rientjes@google.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * dm bufio: avoid sleeping while holding the dm_bufio lockDouglas Anderson2016-12-081-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We've seen in-field reports showing _lots_ (18 in one case, 41 in another) of tasks all sitting there blocked on: mutex_lock+0x4c/0x68 dm_bufio_shrink_count+0x38/0x78 shrink_slab.part.54.constprop.65+0x100/0x464 shrink_zone+0xa8/0x198 In the two cases analyzed, we see one task that looks like this: Workqueue: kverityd verity_prefetch_io __switch_to+0x9c/0xa8 __schedule+0x440/0x6d8 schedule+0x94/0xb4 schedule_timeout+0x204/0x27c schedule_timeout_uninterruptible+0x44/0x50 wait_iff_congested+0x9c/0x1f0 shrink_inactive_list+0x3a0/0x4cc shrink_lruvec+0x418/0x5cc shrink_zone+0x88/0x198 try_to_free_pages+0x51c/0x588 __alloc_pages_nodemask+0x648/0xa88 __get_free_pages+0x34/0x7c alloc_buffer+0xa4/0x144 __bufio_new+0x84/0x278 dm_bufio_prefetch+0x9c/0x154 verity_prefetch_io+0xe8/0x10c process_one_work+0x240/0x424 worker_thread+0x2fc/0x424 kthread+0x10c/0x114 ...and that looks to be the one holding the mutex. The problem has been reproduced on fairly easily: 0. Be running Chrome OS w/ verity enabled on the root filesystem 1. Pick test patch: http://crosreview.com/412360 2. Install launchBalloons.sh and balloon.arm from http://crbug.com/468342 ...that's just a memory stress test app. 3. On a 4GB rk3399 machine, run nice ./launchBalloons.sh 4 900 100000 ...that tries to eat 4 * 900 MB of memory and keep accessing. 4. Login to the Chrome web browser and restore many tabs With that, I've seen printouts like: DOUG: long bufio 90758 ms ...and stack trace always show's we're in dm_bufio_prefetch(). The problem is that we try to allocate memory with GFP_NOIO while we're holding the dm_bufio lock. Instead we should be using GFP_NOWAIT. Using GFP_NOIO can cause us to sleep while holding the lock and that causes the above problems. The current behavior explained by David Rientjes: It will still try reclaim initially because __GFP_WAIT (or __GFP_KSWAPD_RECLAIM) is set by GFP_NOIO. This is the cause of contention on dm_bufio_lock() that the thread holds. You want to pass GFP_NOWAIT instead of GFP_NOIO to alloc_buffer() when holding a mutex that can be contended by a concurrent slab shrinker (if count_objects didn't use a trylock, this pattern would trivially deadlock). This change significantly increases responsiveness of the system while in this state. It makes a real difference because it unblocks kswapd. In the bug report analyzed, kswapd was hung: kswapd0 D ffffffc000204fd8 0 72 2 0x00000000 Call trace: [<ffffffc000204fd8>] __switch_to+0x9c/0xa8 [<ffffffc00090b794>] __schedule+0x440/0x6d8 [<ffffffc00090bac0>] schedule+0x94/0xb4 [<ffffffc00090be44>] schedule_preempt_disabled+0x28/0x44 [<ffffffc00090d900>] __mutex_lock_slowpath+0x120/0x1ac [<ffffffc00090d9d8>] mutex_lock+0x4c/0x68 [<ffffffc000708e7c>] dm_bufio_shrink_count+0x38/0x78 [<ffffffc00030b268>] shrink_slab.part.54.constprop.65+0x100/0x464 [<ffffffc00030dbd8>] shrink_zone+0xa8/0x198 [<ffffffc00030e578>] balance_pgdat+0x328/0x508 [<ffffffc00030eb7c>] kswapd+0x424/0x51c [<ffffffc00023f06c>] kthread+0x10c/0x114 [<ffffffc000203dd0>] ret_from_fork+0x10/0x40 By unblocking kswapd memory pressure should be reduced. Suggested-by: David Rientjes <rientjes@google.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * dm table: simplify dm_table_determine_type()Bart Van Assche2016-12-081-13/+8
| | | | | | | | | | | | | | | | Use a single loop instead of two loops to determine whether or not all_blk_mq has to be set. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * dm table: an 'all_blk_mq' table must be loaded for a blk-mq DM deviceBart Van Assche2016-12-081-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | When dm_table_set_type() is used by a target to establish a DM table's type (e.g. DM_TYPE_MQ_REQUEST_BASED in the case of DM multipath) the DM core must go on to verify that the devices in the table are compatible with the established type. Fixes: e83068a5 ("dm mpath: add optional "queue_mode" feature") Cc: stable@vger.kernel.org # 4.8+ Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * dm table: fix 'all_blk_mq' inconsistency when an empty table is loadedMike Snitzer2016-12-081-6/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | An earlier DM multipath table could have been build ontop of underlying devices that were all using blk-mq. In that case, if that active multipath table is replaced with an empty DM multipath table (that reflects all paths have failed) then it is important that the 'all_blk_mq' state of the active table is transfered to the new empty DM table. Otherwise dm-rq.c:dm_old_prep_tio() will incorrectly clone a request that isn't needed by the DM multipath target when it is to issue IO to an underlying blk-mq device. Fixes: e83068a5 ("dm mpath: add optional "queue_mode" feature") Cc: stable@vger.kernel.org # 4.8+ Reported-by: Bart Van Assche <bart.vanassche@sandisk.com> Tested-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * dm mpath: do not modify *__clone if blk_mq_alloc_request() failsBart Van Assche2016-11-211-7/+8
| | | | | | | | | | | | | | | | | | Purely cleanup, avoids potential for strange coding bugs. But in reality if __multipath_map() fails the caller has no business looking at *__clone. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * dm mpath: change return type of pg_init_all_paths() from int to voidBart Van Assche2016-11-211-5/+2
| | | | | | | | | | | | | | None of the callers of pg_init_all_paths() check its return value. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * dm mpath: add checks for priority group count to avoid invalid memory accesstang.junhui2016-11-211-2/+2
| | | | | | | | | | | | | | | | | | | | This avoids the potential for invalid memory access, if/when there are no priority groups, in response to invalid arguments being sent by the user via DM message (e.g. "switch_group", "disable_group" or "enable_group"). Signed-off-by: tang.junhui <tang.junhui@zte.com.cn> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * dm mpath: add m->hw_handler_name NULL pointer check in parse_hw_handler()tang.junhui2016-11-211-0/+2
| | | | | | | | | | | | | | | | Avoids false positive of no hardware handler being specified (which is implied by a NULL m->hw_handler_name). Signed-off-by: tang.junhui <tang.junhui@zte.com.cn> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * dm flakey: return -EINVAL on interval bounds error in flakey_ctr()Wei Yongjun2016-11-211-0/+2
| | | | | | | | | | | | | | | | | | | | Fix to return error code -EINVAL instead of 0, as is done elsewhere in this function. Fixes: e80d1c805a3b ("dm: do not override error code returned from dm_get_device()") Cc: stable@vger.kernel.org # 4.3+ Signed-off-by: Wei Yongjun <weiyj.lk@gmail.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * dm crypt: constify crypt_iv_operations structuresJulia Lawall2016-11-211-8/+8
| | | | | | | | | | | | | | | | | | | | The crypt_iv_operations are never modified, so declare them as const. Done with the help of Coccinelle. Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * dm raid: correct error messages on old metadata validationHeinz Mauelshagen2016-11-211-32/+39
| | | | | | | | | | | | | | | | | | | | | | | | | | | | When target 1.9.1 gets takeover/reshape requests on devices with old superblock format not supporting such conversions and rejects them in super_init_validation(), it logs bogus error message (e.g. Reshape when a takeover is requested). Whilst on it, add messages for disk adding/removing and stripe sectors reshape requests, use the newer rs_{takeover,reshape}_requested() API, address a raid10 false positive in checking array positions and remove rs_set_new() because device members are already set proper. Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * dm cache: add missing cache device name to DMERR in set_cache_mode()Mike Snitzer2016-11-211-1/+2
| | | | | | | | Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * dm cache metadata: remove an extra newline in DMERR and codeMike Snitzer2016-11-211-2/+1
| | | | | | | | Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * dm verity: fix incorrect error messageEric Biggers2016-11-211-1/+1
| | | | | | | | | | Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * dm crypt: rename crypt_setkey_allcpus to crypt_setkeyMikulas Patocka2016-11-211-3/+3
| | | | | | | | | | | | | | | | | | | | In the past, dm-crypt used per-cpu crypto context. This has been removed in the kernel 3.15 and the crypto context is shared between all cpus. This patch renames the function crypt_setkey_allcpus to crypt_setkey, because there is really no activity that is done for all cpus. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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