kernel/git/next/linux-next.git/drivers/md/dm-bufio.c, branch akpm

mm: shrinkers: provide shrinkers with names

2022-06-27T20:45:17+00:00

Currently shrinkers are anonymous objects. For debugging purposes they can be identified by count/scan function names, but it's not always useful: e.g. for superblock's shrinkers it's nice to have at least an idea of to which superblock the shrinker belongs. This commit adds names to shrinkers. register_shrinker() and prealloc_shrinker() functions are extended to take a format and arguments to master a name. In some cases it's not possible to determine a good name at the time when a shrinker is allocated. For such cases shrinker_debugfs_rename() is provided. The expected format is: -[:]- For some shrinkers an instance can be encoded as (MAJOR:MINOR) pair. After this change the shrinker debugfs directory looks like: $ cd /sys/kernel/debug/shrinker/ $ ls dquota-cache-16 sb-devpts-28 sb-proc-47 sb-tmpfs-42 mm-shadow-18 sb-devtmpfs-5 sb-proc-48 sb-tmpfs-43 mm-zspool:zram0-34 sb-hugetlbfs-17 sb-pstore-31 sb-tmpfs-44 rcu-kfree-0 sb-hugetlbfs-33 sb-rootfs-2 sb-tmpfs-49 sb-aio-20 sb-iomem-12 sb-securityfs-6 sb-tracefs-13 sb-anon_inodefs-15 sb-mqueue-21 sb-selinuxfs-22 sb-xfs:vda1-36 sb-bdev-3 sb-nsfs-4 sb-sockfs-8 sb-zsmalloc-19 sb-bpf-32 sb-pipefs-14 sb-sysfs-26 thp-deferred_split-10 sb-btrfs:vda2-24 sb-proc-25 sb-tmpfs-1 thp-zero-9 sb-cgroup2-30 sb-proc-39 sb-tmpfs-27 xfs-buf:vda1-37 sb-configfs-23 sb-proc-41 sb-tmpfs-29 xfs-inodegc:vda1-38 sb-dax-11 sb-proc-45 sb-tmpfs-35 sb-debugfs-7 sb-proc-46 sb-tmpfs-40 Link: https://lkml.kernel.org/r/20220601032227.4076670-4-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin Cc: Christophe JAILLET Cc: Dave Chinner Cc: Hillf Danton Cc: Kent Overstreet Cc: Muchun Song Signed-off-by: Andrew Morton

block: turn bio_kmalloc into a simple kmalloc wrapper

2022-04-18T01:30:41+00:00

Remove the magic autofree semantics and require the callers to explicitly call bio_init to initialize the bio. This allows bio_free to catch accidental bio_put calls on bio_init()ed bios as well. Signed-off-by: Christoph Hellwig Acked-by: Coly Li Acked-by: Mike Snitzer Link: https://lore.kernel.org/r/20220406061228.410163-5-hch@lst.de Signed-off-by: Jens Axboe

Merge tag 'for-5.16/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

2021-11-09T19:02:04+00:00

Pull device mapper updates from Mike Snitzer: - Add DM core support for emitting audit events through the audit subsystem. Also enhance both the integrity and crypt targets to emit events to via dm-audit. - Various other simple code improvements and cleanups. * tag 'for-5.16/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm table: log table creation error code dm: make workqueue names device-specific dm writecache: Make use of the helper macro kthread_run() dm crypt: Make use of the helper macro kthread_run() dm verity: use bvec_kmap_local in verity_for_bv_block dm log writes: use memcpy_from_bvec in log_writes_map dm integrity: use bvec_kmap_local in __journal_read_write dm integrity: use bvec_kmap_local in integrity_metadata dm: add add_disk() error handling dm: Remove redundant flush_workqueue() calls dm crypt: log aead integrity violations to audit subsystem dm integrity: log audit events for dm-integrity target dm: introduce audit event module for device mapper

dm: Remove redundant flush_workqueue() calls

2021-11-01T17:28:43+00:00

destroy_workqueue() already drains the queue before destroying it, so there is no need to flush it explicitly. Remove the redundant flush_workqueue() calls. This was generated with coccinelle: @@ expression E; @@ - flush_workqueue(E); destroy_workqueue(E); Signed-off-by: Christophe JAILLET Signed-off-by: Mike Snitzer

dm: use bdev_nr_sectors and bdev_nr_bytes instead of open coding them

2021-10-18T20:43:22+00:00

Use the proper helpers to read the block device size. Signed-off-by: Christoph Hellwig Reviewed-by: Kees Cook Acked-by: Mike Snitzer Link: https://lore.kernel.org/r/20211018101130.1838532-6-hch@lst.de Signed-off-by: Jens Axboe

dm bufio: subtract the number of initial sectors in dm_bufio_get_device_size

2021-03-04T19:53:54+00:00

dm_bufio_get_device_size returns the device size in blocks. Before returning the value, we must subtract the nubmer of starting sectors. The number of starting sectors may not be divisible by block size. Note that currently, no target is using dm_bufio_set_sector_offset and dm_bufio_get_device_size simultaneously, so this change has no effect. However, an upcoming dm-verity-fec fix needs this change. Signed-off-by: Mikulas Patocka Reviewed-by: Milan Broz Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer

dm integrity: fix flush with external metadata device

2021-01-08T20:57:29+00:00

With external metadata device, flush requests are not passed down to the data device. Fix this by submitting the flush request in dm_integrity_flush_buffers. In order to not degrade performance, we overlap the data device flush with the metadata device flush. Reported-by: Lukas Straub Signed-off-by: Mikulas Patocka Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer

dm bufio: do buffer cleanup from a workqueue

2020-07-20T15:17:43+00:00

Until now, DM bufio's waiting for IO from reclaim context in its shrinker has caused kswapd to block; which results in systemic IO stalls and even deadlock, e.g.: https://www.redhat.com/archives/dm-devel/2020-March/msg00025.html Here is Dave Chinner's problem description that motivated this fix, from: https://lore.kernel.org/linux-fsdevel/20190809215733.GZ7777@dread.disaster.area/ "Waiting for IO in kswapd reclaim context is considered harmful - kswapd context shrinker reclaim should be as non-blocking as possible, and any back-off to wait for IO to complete should be done by the high level reclaim core once it's completed an entire reclaim scan cycle of everything.... What follows from that, and is pertinent in this situation, is that if you don't block kswapd, then other reclaim contexts are not going to get stuck waiting for it regardless of the reclaim context they use." Continued elsewhere: "The only way to fix this problem once and for all is to stop using the shrinker as a mechanism to issue and wait on IO. If you need background writeback of dirty buffers, do it from a WQ_MEM_RECLAIM workqueue that isn't directly in the memory reclaim path and so can issue writeback and block safely from a GFP_KERNEL context. Kick the workqueue from the shrinker context, but get rid of the IO submission and waiting from the shrinker and all the GFP_NOFS memory reclaim recursion problems go away." As such, this commit moves buffer cleanup to a workqueue. Suggested-by: Dave Chinner Reported-by: Tahsin Erdogan Signed-off-by: Mikulas Patocka Tested-by: Gabriel Krisman Bertazi Signed-off-by: Mike Snitzer

Merge tag 'for-5.8/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

2020-06-05T22:45:03+00:00

Pull device mapper updates from Mike Snitzer: - The largest change for this cycle is the DM zoned target's metadata version 2 feature that adds support for pairing regular block devices with a zoned device to ease the performance impact associated with finite random zones of zoned device. The changes came in three batches: the first prepared for and then added the ability to pair a single regular block device, the second was a batch of fixes to improve zoned's reclaim heuristic, and the third removed the limitation of only adding a single additional regular block device to allow many devices. Testing has shown linear scaling as more devices are added. - Add new emulated block size (ebs) target that emulates a smaller logical_block_size than a block device supports The primary use-case is to emulate "512e" devices that have 512 byte logical_block_size and 4KB physical_block_size. This is useful to some legacy applications that otherwise wouldn't be able to be used on 4K devices because they depend on issuing IO in 512 byte granularity. - Add discard interfaces to DM bufio. First consumer of the interface is the dm-ebs target that makes heavy use of dm-bufio. - Fix DM crypt's block queue_limits stacking to not truncate logic_block_size. - Add Documentation for DM integrity's status line. - Switch DMDEBUG from a compile time config option to instead use dynamic debug via pr_debug. - Fix DM multipath target's hueristic for how it manages "queue_if_no_path" state internally. DM multipath now avoids disabling "queue_if_no_path" unless it is actually needed (e.g. in response to configure timeout or explicit "fail_if_no_path" message). This fixes reports of spurious -EIO being reported back to userspace application during fault tolerance testing with an NVMe backend. Added various dynamic DMDEBUG messages to assist with debugging queue_if_no_path in the future. - Add a new DM multipath "Historical Service Time" Path Selector. - Fix DM multipath's dm_blk_ioctl() to switch paths on IO error. - Improve DM writecache target performance by using explicit cache flushing for target's single-threaded usecase and a small cleanup to remove unnecessary test in persistent_memory_claim. - Other small cleanups in DM core, dm-persistent-data, and DM integrity. * tag 'for-5.8/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (62 commits) dm crypt: avoid truncating the logical block size dm mpath: add DM device name to Failing/Reinstating path log messages dm mpath: enhance queue_if_no_path debugging dm mpath: restrict queue_if_no_path state machine dm mpath: simplify __must_push_back dm zoned: check superblock location dm zoned: prefer full zones for reclaim dm zoned: select reclaim zone based on device index dm zoned: allocate zone by device index dm zoned: support arbitrary number of devices dm zoned: move random and sequential zones into struct dmz_dev dm zoned: per-device reclaim dm zoned: add metadata pointer to struct dmz_dev dm zoned: add device pointer to struct dm_zone dm zoned: allocate temporary superblock for tertiary devices dm zoned: convert to xarray dm zoned: add a 'reserved' zone flag dm zoned: improve logging messages for reclaim dm zoned: avoid unnecessary device recalulation for secondary superblock dm zoned: add debugging message for reading superblocks ...

dm bufio: introduce forget_buffer_locked

2020-06-05T18:59:41+00:00

Introduce a function forget_buffer_locked that forgets a range of buffers. It is more efficient than calling forget_buffer in a loop. Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer