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2023-06-23dm ioctl: structs and parameter strings must not overlapDemi Marie Obenour1-7/+21
The NUL terminator for each target parameter string must precede the following 'struct dm_target_spec'. Otherwise, dm_split_args() might corrupt this struct. Furthermore, the first 'struct dm_target_spec' must come after the 'struct dm_ioctl', as if it overlaps too much dm_split_args() could corrupt the 'struct dm_ioctl'. Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com> Reviewed-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-06-23dm ioctl: Avoid pointer arithmetic overflowDemi Marie Obenour1-0/+16
Especially on 32-bit systems, it is possible for the pointer arithmetic to overflow and cause a userspace pointer to be dereferenced in the kernel. Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com> Reviewed-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-06-23dm ioctl: Check dm_target_spec is sufficiently alignedDemi Marie Obenour1-0/+9
Otherwise subsequent code, if given malformed input, could dereference a misaligned 'struct dm_target_spec *'. Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> # use %zu Reviewed-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-06-23dm integrity: Use %*ph for printing hexdump of a small bufferAndy Shevchenko1-18/+3
The kernel already has a helper to print a hexdump of a small buffer via pointer extension. Use that instead of open coded variant. In long term it helps to kill pr_cont() or at least narrow down its use. Note, the format is slightly changed, i.e. the trailing space is always printed. Also the IV dump is limited by 64 bytes which seems fine. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-06-21Merge tag 'mm-hotfixes-stable-2023-06-20-12-31' of ↵Linus Torvalds2-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull hotfixes from Andrew Morton: "19 hotfixes. 8 of these are cc:stable. This includes a wholesale reversion of the post-6.4 series 'make slab shrink lockless'. After input from Dave Chinner it has been decided that we should go a different way [1]" Link: https://lkml.kernel.org/r/ZH6K0McWBeCjaf16@dread.disaster.area [1] * tag 'mm-hotfixes-stable-2023-06-20-12-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: selftests/mm: fix cross compilation with LLVM mailmap: add entries for Ben Dooks nilfs2: prevent general protection fault in nilfs_clear_dirty_page() Revert "mm: vmscan: make global slab shrink lockless" Revert "mm: vmscan: make memcg slab shrink lockless" Revert "mm: vmscan: add shrinker_srcu_generation" Revert "mm: shrinkers: make count and scan in shrinker debugfs lockless" Revert "mm: vmscan: hold write lock to reparent shrinker nr_deferred" Revert "mm: vmscan: remove shrinker_rwsem from synchronize_shrinkers()" Revert "mm: shrinkers: convert shrinker_rwsem to mutex" nilfs2: fix buffer corruption due to concurrent device reads scripts/gdb: fix SB_* constants parsing scripts: fix the gfp flags header path in gfp-translate udmabuf: revert 'Add support for mapping hugepages (v4)' mm/khugepaged: fix iteration in collapse_file memfd: check for non-NULL file_seals in memfd_create() syscall mm/vmalloc: do not output a spurious warning when huge vmalloc() fails mm/mprotect: fix do_mprotect_pkey() limit check writeback: fix dereferencing NULL mapping->host on writeback_page_template
2023-06-20dm-crypt: use ARCH_DMA_MINALIGN instead of ARCH_KMALLOC_MINALIGNCatalin Marinas1-1/+1
ARCH_DMA_MINALIGN represents the minimum (static) alignment for safe DMA operations while ARCH_KMALLOC_MINALIGN is the minimum kmalloc() objects alignment. Link: https://lkml.kernel.org/r/20230612153201.554742-10-catalin.marinas@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Isaac J. Manjarres <isaacmanjarres@google.com> Cc: Alasdair Kergon <agk@redhat.com> Cc: Mike Snitzer <snitzer@kernel.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Jerry Snitselaar <jsnitsel@redhat.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Jonathan Cameron <jic23@kernel.org> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Lars-Peter Clausen <lars@metafoo.de> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Mark Brown <broonie@kernel.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Saravana Kannan <saravanak@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-19Revert "mm: shrinkers: convert shrinker_rwsem to mutex"Qi Zheng2-2/+2
Patch series "revert shrinker_srcu related changes". This patch (of 7): This reverts commit cf2e309ebca7bb0916771839f9b580b06c778530. Kernel test robot reports -88.8% regression in stress-ng.ramfs.ops_per_sec test case [1], which is caused by commit f95bdb700bc6 ("mm: vmscan: make global slab shrink lockless"). The root cause is that SRCU has to be careful to not frequently check for SRCU read-side critical section exits. Therefore, even if no one is currently in the SRCU read-side critical section, synchronize_srcu() cannot return quickly. That's why unregister_shrinker() has become slower. After discussion, we will try to use the refcount+RCU method [2] proposed by Dave Chinner to continue to re-implement the lockless slab shrink. So revert the shrinker_mutex back to shrinker_rwsem first. [1]. https://lore.kernel.org/lkml/202305230837.db2c233f-yujie.liu@intel.com/ [2]. https://lore.kernel.org/lkml/ZIJhou1d55d4H1s0@dread.disaster.area/ Link: https://lkml.kernel.org/r/20230609081518.3039120-1-qi.zheng@linux.dev Link: https://lkml.kernel.org/r/20230609081518.3039120-2-qi.zheng@linux.dev Reported-by: kernel test robot <yujie.liu@intel.com> Closes: https://lore.kernel.org/oe-lkp/202305230837.db2c233f-yujie.liu@intel.com Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Kirill Tkhai <tkhai@ya.ru> Cc: Muchun Song <muchun.song@linux.dev> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yujie Liu <yujie.liu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-17dm thin: disable discards for thin-pool if no_discard_passdownMike Snitzer1-8/+5
Also rename disable_passdown_if_not_supported to disable_discard_passdown_if_not_supported. And fold passdown_enabled() into only caller. Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-06-17dm: remove stale/redundant dm_internal_{suspend,resume} prototypes in dm.hMike Snitzer1-3/+0
dm_internal_suspend() no longer exists. Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-06-17dm: skip dm-stats work in alloc_io() unless neededMike Snitzer1-1/+2
Don't dm_stats_record_start() if dm_stats_used() is false. Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-06-17dm: avoid needless dm_io access if all IO accounting is disabledMike Snitzer1-22/+21
Update dm_io_acct() to eliminate most dm_io struct accesses if both block core's IO stats and dm-stats are disabled. Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-06-17dm: support turning off block-core's io stats accountingLi Nan2-6/+13
Commit bc58ba9468d9 ("block: add sysfs file for controlling io stats accounting") allowed users to turn off disk stat accounting completely by checking if queue flag QUEUE_FLAG_IO_STAT is set. In dm, this flag is neither set nor checked: so block-core's io stats are continuously counted and cannot be turned off. Add support for turning off block-core's io stats accounting for dm. Set QUEUE_FLAG_IO_STAT for dm's request_queue. If QUEUE_FLAG_IO_STAT is set when an io starts, record the need for block core's io stats by setting the DM_IO_BLK_STAT dm_io flag to avoid io stats being disabled in the middle of the io. DM statistics (dm-stats) is independent of block-core's io stats and remains unchanged. Signed-off-by: Li Nan <linan122@huawei.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-06-17dm zone: Use the bitmap API to allocate bitmapsChristophe JAILLET1-8/+7
Use bitmap_zalloc()/bitmap_free() instead of hand-writing them. It is less verbose and it improves the semantic. Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-06-17dm thin metadata: Fix ABBA deadlock by resetting dm_bufio_clientLi Lingfeng6-34/+44
As described in commit 8111964f1b85 ("dm thin: Fix ABBA deadlock between shrink_slab and dm_pool_abort_metadata"), ABBA deadlocks will be triggered because shrinker_rwsem currently needs to held by dm_pool_abort_metadata() as a side-effect of thin-pool metadata operation failure. The following three problem scenarios have been noticed: 1) Described by commit 8111964f1b85 ("dm thin: Fix ABBA deadlock between shrink_slab and dm_pool_abort_metadata") 2) shrinker_rwsem and throttle->lock P1(drop cache) P2(kworker) drop_caches_sysctl_handler drop_slab shrink_slab down_read(&shrinker_rwsem) - LOCK A do_shrink_slab super_cache_scan prune_icache_sb dispose_list evict ext4_evict_inode ext4_clear_inode ext4_discard_preallocations ext4_mb_load_buddy_gfp ext4_mb_init_cache ext4_wait_block_bitmap __ext4_error ext4_handle_error ext4_commit_super ... dm_submit_bio do_worker throttle_work_update down_write(&t->lock) -- LOCK B process_deferred_bios commit metadata_operation_failed dm_pool_abort_metadata dm_block_manager_create dm_bufio_client_create register_shrinker down_write(&shrinker_rwsem) -- LOCK A thin_map thin_bio_map thin_defer_bio_with_throttle throttle_lock down_read(&t->lock) - LOCK B 3) shrinker_rwsem and wait_on_buffer P1(drop cache) P2(kworker) drop_caches_sysctl_handler drop_slab shrink_slab down_read(&shrinker_rwsem) - LOCK A do_shrink_slab ... ext4_wait_block_bitmap __ext4_error ext4_handle_error jbd2_journal_abort jbd2_journal_update_sb_errno jbd2_write_superblock submit_bh // LOCK B // RELEASE B do_worker throttle_work_update down_write(&t->lock) - LOCK B process_deferred_bios process_bio commit metadata_operation_failed dm_pool_abort_metadata dm_block_manager_create dm_bufio_client_create register_shrinker register_shrinker_prepared down_write(&shrinker_rwsem) - LOCK A bio_endio wait_on_buffer __wait_on_buffer Fix these by resetting dm_bufio_client without holding shrinker_rwsem. Fixes: 8111964f1b85 ("dm thin: Fix ABBA deadlock between shrink_slab and dm_pool_abort_metadata") Cc: stable@vger.kernel.org Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-06-17dm crypt: fix crypt_ctr_cipher_new return value on invalid AEAD cipherMikulas Patocka1-1/+1
If the user specifies invalid AEAD cipher, dm-crypt should return the error returned from crypt_ctr_auth_spec, not -ENOMEM. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-06-17dm thin: update .io_hints methods to not require handling discards lastMike Snitzer1-14/+12
Removes assumptions about what might follow the discard setup code (previously the code would return early if discards not enabled). Makes it possible to add more capabilites to the end of each .io_hints method (which is the natural thing to do when adding new features). Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-06-17dm thin: remove return code variable in pool_mapMike Snitzer1-3/+1
Always returns DM_MAPIO_REMAPPED so no need for variable. Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-06-17dm flakey: introduce random_read_corrupt and random_write_corrupt optionsMikulas Patocka1-20/+100
The random_read_corrupt and random_write_corrupt options corrupt a random byte in a bio with the provided probability. The corruption only happens in the "down" interval. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-06-17dm flakey: clone pages on write bio before corrupting themMikulas Patocka1-9/+95
dm-flakey has an option to corrupt write bios. It corrupts the memory that is being written. This can cause system crashes or security bugs - for example, if the user writes a shared library code with O_DIRECT flag to a dm-flakey device, it corrupts the memory for all users that have the shared library mapped. Fix this bug by cloning the bio and corrupting the clone rather than the original. Also drop the test for ZERO_PAGE(0) - it can't happen because we write the cloned pages. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-06-17dm crypt: allocate compound pages if possibleMikulas Patocka1-14/+35
It was reported that allocating pages for the write buffer in dm-crypt causes measurable overhead [1]. Change dm-crypt to allocate compound pages if they are available. If not, fall back to the mempool. [1] https://listman.redhat.com/archives/dm-devel/2023-February/053284.html Suggested-by: Matthew Wilcox <willy@infradead.org> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-06-16Merge tag 'for-6.4/dm-fixes' of ↵Linus Torvalds4-23/+34
git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper fixes from Mike Snitzer: - Fix DM thinp discard performance regression introduced during this merge window where DM core was splitting large discards every 128K (max_sectors_kb) rather than every 64M (discard_max_bytes). - Extend DM core LOCKFS fix, made during 6.4 merge, to also fix race between do_mount and dm's do_suspend (in addition to the earlier fix's do_mount race with dm's do_resume). - Fix DM thin metadata operations to first check if the thin-pool is in "fail_io" mode; otherwise UAF can occur. - Fix DM thinp's call to __blkdev_issue_discard to use GFP_NOIO rather than GFP_NOWAIT (__blkdev_issue_discard cannot handle NULL return from bio_alloc). * tag 'for-6.4/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm: use op specific max_sectors when splitting abnormal io dm thin: fix issue_discard to pass GFP_NOIO to __blkdev_issue_discard dm thin metadata: check fail_io before using data_sm dm: don't lock fs when the map is NULL during suspend or resume
2023-06-15dm: use op specific max_sectors when splitting abnormal ioMike Snitzer1-9/+16
Split abnormal IO in terms of the corresponding operation specific max_sectors (max_discard_sectors, max_secure_erase_sectors or max_write_zeroes_sectors). This fixes a significant dm-thinp discard performance regression that was introduced with commit e2dd8aca2d76 ("dm bio prison v1: improve concurrent IO performance"). Relative to discard: max_discard_sectors is used instead of max_sectors; which fixes excessive discard splitting (e.g. max_sectors=128K vs max_discard_sectors=64M). Tested by discarding an 1 Petabyte dm-thin device: lvcreate -V 1125899906842624B -T test/pool -n thin time blkdiscard /dev/test/thin Before this fix (splitting discards every 128K): ~116m After this fix (splitting discards every 64M) : 0m33.460s Reported-by: Zorro Lang <zlang@redhat.com> Fixes: 06961c487a33 ("dm: split discards further if target sets max_discard_granularity") Requires: 13f6facf3fae ("dm: allow targets to require splitting WRITE_ZEROES and SECURE_ERASE") Fixes: e2dd8aca2d76 ("dm bio prison v1: improve concurrent IO performance") Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-06-15dm thin: fix issue_discard to pass GFP_NOIO to __blkdev_issue_discardMike Snitzer1-2/+1
issue_discard() passes GFP_NOWAIT to __blkdev_issue_discard() despite its code assuming bio_alloc() always succeeds. Commit 3dba53a958a75 ("dm thin: use __blkdev_issue_discard for async discard support") clearly shows where things went bad: Before commit 3dba53a958a75, dm-thin.c's open-coded __blkdev_issue_discard_async() properly handled using GFP_NOWAIT. Unfortunately __blkdev_issue_discard() doesn't and it was missed during review. Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-06-15dm thin metadata: check fail_io before using data_smLi Lingfeng1-8/+12
Must check pmd->fail_io before using pmd->data_sm since pmd->data_sm may be destroyed by other processes. P1(kworker) P2(message) do_worker process_prepared process_prepared_discard_passdown_pt2 dm_pool_dec_data_range pool_message commit dm_pool_commit_metadata ↓ // commit failed metadata_operation_failed abort_transaction dm_pool_abort_metadata __open_or_format_metadata ↓ dm_sm_disk_open ↓ // open failed // pmd->data_sm is NULL dm_sm_dec_blocks ↓ // try to access pmd->data_sm --> UAF As shown above, if dm_pool_commit_metadata() and dm_pool_abort_metadata() fail in pool_message process, kworker may trigger UAF. Fixes: be500ed721a6 ("dm space maps: improve performance with inc/dec on ranges of blocks") Cc: stable@vger.kernel.org Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-06-15dm: don't lock fs when the map is NULL during suspend or resumeLi Lingfeng2-4/+5
As described in commit 38d11da522aa ("dm: don't lock fs when the map is NULL in process of resume"), a deadlock may be triggered between do_resume() and do_mount(). This commit preserves the fix from commit 38d11da522aa but moves it to where it also serves to fix a similar deadlock between do_suspend() and do_mount(). It does so, if the active map is NULL, by clearing DM_SUSPEND_LOCKFS_FLAG in dm_suspend() which is called by both do_suspend() and do_resume(). Fixes: 38d11da522aa ("dm: don't lock fs when the map is NULL in process of resume") Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-06-15bcache: fixup btree_cache_wait list damageMingzhe Zou3-1/+21
We get a kernel crash about "list_add corruption. next->prev should be prev (ffff9c801bc01210), but was ffff9c77b688237c. (next=ffffae586d8afe68)." crash> struct list_head 0xffff9c801bc01210 struct list_head { next = 0xffffae586d8afe68, prev = 0xffffae586d8afe68 } crash> struct list_head 0xffff9c77b688237c struct list_head { next = 0x0, prev = 0x0 } crash> struct list_head 0xffffae586d8afe68 struct list_head struct: invalid kernel virtual address: ffffae586d8afe68 type: "gdb_readmem_callback" Cannot access memory at address 0xffffae586d8afe68 [230469.019492] Call Trace: [230469.032041] prepare_to_wait+0x8a/0xb0 [230469.044363] ? bch_btree_keys_free+0x6c/0xc0 [escache] [230469.056533] mca_cannibalize_lock+0x72/0x90 [escache] [230469.068788] mca_alloc+0x2ae/0x450 [escache] [230469.080790] bch_btree_node_get+0x136/0x2d0 [escache] [230469.092681] bch_btree_check_thread+0x1e1/0x260 [escache] [230469.104382] ? finish_wait+0x80/0x80 [230469.115884] ? bch_btree_check_recurse+0x1a0/0x1a0 [escache] [230469.127259] kthread+0x112/0x130 [230469.138448] ? kthread_flush_work_fn+0x10/0x10 [230469.149477] ret_from_fork+0x35/0x40 bch_btree_check_thread() and bch_dirty_init_thread() may call mca_cannibalize() to cannibalize other cached btree nodes. Only one thread can do it at a time, so the op of other threads will be added to the btree_cache_wait list. We must call finish_wait() to remove op from btree_cache_wait before free it's memory address. Otherwise, the list will be damaged. Also should call bch_cannibalize_unlock() to release the btree_cache_alloc_lock and wake_up other waiters. Fixes: 8e7102273f59 ("bcache: make bch_btree_check() to be multithreaded") Fixes: b144e45fc576 ("bcache: make bch_sectors_dirty_init() to be multithreaded") Cc: stable@vger.kernel.org Signed-off-by: Mingzhe Zou <mingzhe.zou@easystack.cn> Signed-off-by: Coly Li <colyli@suse.de> Link: https://lore.kernel.org/r/20230615121223.22502-7-colyli@suse.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-15bcache: Fix __bch_btree_node_alloc to make the failure behavior consistentZheng Wang1-1/+3
In some specific situations, the return value of __bch_btree_node_alloc may be NULL. This may lead to a potential NULL pointer dereference in caller function like a calling chain : btree_split->bch_btree_node_alloc->__bch_btree_node_alloc. Fix it by initializing the return value in __bch_btree_node_alloc. Fixes: cafe56359144 ("bcache: A block layer cache") Cc: stable@vger.kernel.org Signed-off-by: Zheng Wang <zyytlz.wz@163.com> Signed-off-by: Coly Li <colyli@suse.de> Link: https://lore.kernel.org/r/20230615121223.22502-6-colyli@suse.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-15bcache: Remove unnecessary NULL point check in node allocationsZheng Wang2-7/+7
Due to the previous fix of __bch_btree_node_alloc, the return value will never be a NULL pointer. So IS_ERR is enough to handle the failure situation. Fix it by replacing IS_ERR_OR_NULL check by an IS_ERR check. Fixes: cafe56359144 ("bcache: A block layer cache") Cc: stable@vger.kernel.org Signed-off-by: Zheng Wang <zyytlz.wz@163.com> Signed-off-by: Coly Li <colyli@suse.de> Link: https://lore.kernel.org/r/20230615121223.22502-5-colyli@suse.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-15bcache: Remove dead references to cache_readaheadsAndrea Tomassetti1-1/+0
The cache_readaheads stat counter is not used anymore and should be removed. Signed-off-by: Andrea Tomassetti <andrea.tomassetti-opensource@devo.com> Signed-off-by: Coly Li <colyli@suse.de> Link: https://lore.kernel.org/r/20230615121223.22502-4-colyli@suse.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-15bcache: make kobj_type structures constantThomas Weißschuh2-6/+6
Since commit ee6d3dd4ed48 ("driver core: make kobj_type constant.") the driver core allows the usage of const struct kobj_type. Take advantage of this to constify the structure definitions to prevent modification at runtime. Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Signed-off-by: Coly Li <colyli@suse.de> Link: https://lore.kernel.org/r/20230615121223.22502-3-colyli@suse.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-15bcache: Convert to use sysfs_emit()/sysfs_emit_at() APIsye xingchen1-16/+15
Follow the advice of the Documentation/filesystems/sysfs.rst and show() should only use sysfs_emit() or sysfs_emit_at() when formatting the value to be returned to user space. Signed-off-by: ye xingchen <ye.xingchen@zte.com.cn> Signed-off-by: Coly Li <colyli@suse.de> Link: https://lore.kernel.org/r/20230615121223.22502-2-colyli@suse.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-14md/raid1-10: limit the number of plugged bioYu Kuai3-3/+10
bio can be added to plug infinitely, and following writeback test can trigger huge amount of plugged bio: Test script: modprobe brd rd_nr=4 rd_size=10485760 mdadm -CR /dev/md0 -l10 -n4 /dev/ram[0123] --assume-clean --bitmap=internal echo 0 > /proc/sys/vm/dirty_background_ratio fio -filename=/dev/md0 -ioengine=libaio -rw=write -bs=4k -numjobs=1 -iodepth=128 -name=test Test result: Monitor /sys/block/md0/inflight will found that inflight keep increasing until fio finish writing, after running for about 2 minutes: [root@fedora ~]# cat /sys/block/md0/inflight 0 4474191 Fix the problem by limiting the number of plugged bio based on the number of copies for original bio. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230529131106.2123367-8-yukuai1@huaweicloud.com
2023-06-14md/raid1-10: don't handle pluged bio by daemon threadYu Kuai3-7/+19
current->bio_list will be set under submit_bio() context, in this case bitmap io will be added to the list and wait for current io submission to finish, while current io submission must wait for bitmap io to be done. commit 874807a83139 ("md/raid1{,0}: fix deadlock in bitmap_unplug.") fix the deadlock by handling plugged bio by daemon thread. On the one hand, the deadlock won't exist after commit a214b949d8e3 ("blk-mq: only flush requests from the plug in blk_mq_submit_bio"). On the other hand, current solution makes it impossible to flush plugged bio in raid1/10_make_request(), because this will cause that all the writes will goto daemon thread. In order to limit the number of plugged bio, commit 874807a83139 ("md/raid1{,0}: fix deadlock in bitmap_unplug.") is reverted, and the deadlock is fixed by handling bitmap io asynchronously. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230529131106.2123367-7-yukuai1@huaweicloud.com
2023-06-14md/md-bitmap: add a new helper to unplug bitmap asynchrouslyYu Kuai4-0/+40
If bitmap is enabled, bitmap must update before submitting write io, this is why unplug callback must move these io to 'conf->pending_io_list' if 'current->bio_list' is not empty, which will suffer performance degradation. A new helper md_bitmap_unplug_async() is introduced to submit bitmap io in a kworker, so that submit bitmap io in raid10_unplug() doesn't require that 'current->bio_list' is empty. This patch prepare to limit the number of plugged bio. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230529131106.2123367-6-yukuai1@huaweicloud.com
2023-06-14md/raid1-10: submit write io directly if bitmap is not enabledYu Kuai3-5/+19
Commit 6cce3b23f6f8 ("[PATCH] md: write intent bitmap support for raid10") add bitmap support, and it changed that write io is submitted through daemon thread because bitmap need to be updated before write io. And later, plug is used to fix performance regression because all the write io will go to demon thread, which means io can't be issued concurrently. However, if bitmap is not enabled, the write io should not go to daemon thread in the first place, and plug is not needed as well. Fixes: 6cce3b23f6f8 ("[PATCH] md: write intent bitmap support for raid10") Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230529131106.2123367-5-yukuai1@huaweicloud.com
2023-06-14md/raid1-10: factor out a helper to submit normal writeYu Kuai3-33/+23
There are multiple places to do the same thing, factor out a helper to prevent redundant code, and the helper will be used in following patch as well. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230529131106.2123367-4-yukuai1@huaweicloud.com
2023-06-14md/raid1-10: factor out a helper to add bio to plugYu Kuai3-21/+18
The code in raid1 and raid10 is identical, prepare to limit the number of plugged bios. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230529131106.2123367-3-yukuai1@huaweicloud.com
2023-06-14md/raid10: prevent soft lockup while flush writesYu Kuai1-0/+2
Currently, there is no limit for raid1/raid10 plugged bio. While flushing writes, raid1 has cond_resched() while raid10 doesn't, and too many writes can cause soft lockup. Follow up soft lockup can be triggered easily with writeback test for raid10 with ramdisks: watchdog: BUG: soft lockup - CPU#10 stuck for 27s! [md0_raid10:1293] Call Trace: <TASK> call_rcu+0x16/0x20 put_object+0x41/0x80 __delete_object+0x50/0x90 delete_object_full+0x2b/0x40 kmemleak_free+0x46/0xa0 slab_free_freelist_hook.constprop.0+0xed/0x1a0 kmem_cache_free+0xfd/0x300 mempool_free_slab+0x1f/0x30 mempool_free+0x3a/0x100 bio_free+0x59/0x80 bio_put+0xcf/0x2c0 free_r10bio+0xbf/0xf0 raid_end_bio_io+0x78/0xb0 one_write_done+0x8a/0xa0 raid10_end_write_request+0x1b4/0x430 bio_endio+0x175/0x320 brd_submit_bio+0x3b9/0x9b7 [brd] __submit_bio+0x69/0xe0 submit_bio_noacct_nocheck+0x1e6/0x5a0 submit_bio_noacct+0x38c/0x7e0 flush_pending_writes+0xf0/0x240 raid10d+0xac/0x1ed0 Fix the problem by adding cond_resched() to raid10 like what raid1 did. Note that unlimited plugged bio still need to be optimized, for example, in the case of lots of dirty pages writeback, this will take lots of memory and io will spend a long time in plug, hence io latency is bad. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230529131106.2123367-2-yukuai1@huaweicloud.com
2023-06-14md/raid10: fix io loss while replacement replace rdevLi Nan1-4/+18
When removing a disk with replacement, the replacement will be used to replace rdev. During this process, there is a brief window in which both rdev and replacement are read as NULL in raid10_write_request(). This will result in io not being submitted but it should be. //remove //write raid10_remove_disk raid10_write_request mirror->rdev = NULL read rdev -> NULL mirror->rdev = mirror->replacement mirror->replacement = NULL read replacement -> NULL Fix it by reading replacement first and rdev later, meanwhile, use smp_mb() to prevent memory reordering. Fixes: 475b0321a4df ("md/raid10: writes should get directed to replacement as well as original.") Signed-off-by: Li Nan <linan122@huawei.com> Reviewed-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230602091839.743798-3-linan666@huaweicloud.com
2023-06-14md/raid10: Do not add spare disk when recovery failsLi Nan1-2/+18
In raid10_sync_request(), if data cannot be read from any disk for recovery, it will go to 'giveup' and let 'chunks_skipped' + 1. After multiple 'giveup', when 'chunks_skipped >= geo.raid_disks', it will return 'max_sector', indicating that the recovery has been completed. However, the recovery is just aborted and the data remains inconsistent. Fix it by setting mirror->recovery_disabled, which will prevent the spare disk from being added to this mirror. The same issue also exists during resync, it will be fixed afterwards. Signed-off-by: Li Nan <linan122@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230602091839.743798-2-linan666@huaweicloud.com
2023-06-14md/raid10: clean up md_add_new_disk()Li Nan1-1/+0
Commit 1a855a060665 ("md: fix bug with re-adding of partially recovered device.") only add device which is set to In_sync. But it let devices without metadata cannot be added when they should be. Commit bf572541ab44 ("md: fix regression with re-adding devices to arrays with no metadata") fix the above issue, it set device without metadata to In_sync when add new disk. However, after commit f466722ca614 ("md: Change handling of save_raid_disk and metadata update during recovery.") deletes changes of the first patch, setting In_sync for devcie without metadata is meanless because the flag will be cleared soon and will not be used during this period. Clean it up. Signed-off-by: Li Nan <linan122@huawei.com> Reviewed-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230527101851.3266500-2-linan666@huaweicloud.com
2023-06-14md/raid10: prioritize adding disk to 'removed' mirrorLi Nan1-15/+20
When add a new disk to raid10, it will traverse conf->mirror from start and find one of the following mirror to add: 1. mirror->rdev is set to WantReplacement and it have no replacement, set new disk to mirror->replacement. 2. no mirror->rdev, set new disk to mirror->rdev. There is a array as below (sda is set to WantReplacement): Number Major Minor RaidDevice State 0 8 0 0 active sync set-A /dev/sda - 0 0 1 removed 2 8 32 2 active sync set-A /dev/sdc 3 8 48 3 active sync set-B /dev/sdd Use 'mdadm --add' to add a new disk to this array, the new disk will become sda's replacement instead of add to removed position, which is confusing for users. Meanwhile, after new disk recovery success, sda will be set to Faulty. Prioritize adding disk to 'removed' mirror is a better choice. In the above scenario, the behavior is the same as before, except sda will not be deleted. Before other disks are added, continued use sda is more reliable. Signed-off-by: Li Nan <linan122@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230527092007.3008856-1-linan666@huaweicloud.com
2023-06-14md/raid10: improve code of mrdev in raid10_sync_requestLi Nan1-11/+12
'need_recover' and 'mrdev' are equivalent in raid10_sync_request(), and inc mrdev->nr_pending is unreasonable if don't need recovery. Replace 'need_recover' with 'mrdev', and only inc nr_pending when needed. Signed-off-by: Li Nan <linan122@huawei.com> Reviewed-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230527072218.2365857-3-linan666@huaweicloud.com
2023-06-14md/raid10: fix null-ptr-deref of mreplace in raid10_sync_requestLi Nan1-9/+5
There are two check of 'mreplace' in raid10_sync_request(). In the first check, 'need_replace' will be set and 'mreplace' will be used later if no-Faulty 'mreplace' exists, In the second check, 'mreplace' will be set to NULL if it is Faulty, but 'need_replace' will not be changed accordingly. null-ptr-deref occurs if Faulty is set between two check. Fix it by merging two checks into one. And replace 'need_replace' with 'mreplace' because their values are always the same. Fixes: ee37d7314a32 ("md/raid10: Fix raid10 replace hang when new added disk faulty") Signed-off-by: Li Nan <linan122@huawei.com> Reviewed-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230527072218.2365857-2-linan666@huaweicloud.com
2023-06-14md/raid5: don't start reshape when recovery or replace is in progressYu Kuai1-0/+8
When recovery is interrupted (reboot, etc.) check for MD_RECOVERY_RUNNING is not enough to tell recovery is in progress. Also check recovery_cp before starting reshape. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230529133410.2125914-1-yukuai1@huaweicloud.com
2023-06-14md: protect md_thread with rcuYu Kuai12-81/+97
Currently, there are many places that md_thread can be accessed without protection, following are known scenarios that can cause null-ptr-dereference or uaf: 1) sync_thread that is allocated and started from md_start_sync() 2) mddev->thread can be accessed directly from timeout_store() and md_bitmap_daemon_work() 3) md_unregister_thread() from action_store(). Currently, a global spinlock 'pers_lock' is borrowed to protect 'mddev->thread' in some places, this problem can be fixed likewise, however, use a global lock for all the cases is not good. Fix this problem by protecting all md_thread with rcu. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230523021017.3048783-6-yukuai1@huaweicloud.com
2023-06-14md/bitmap: factor out a helper to set timeoutYu Kuai1-16/+19
Register/unregister 'mddev->thread' are both under 'reconfig_mutex', however, some context didn't hold the mutex to access mddev->thread, which can cause null-ptr-deference: 1) md_bitmap_daemon_work() can be called from md_check_recovery() where 'reconfig_mutex' is not held, deference 'mddev->thread' might cause null-ptr-deference, because md_unregister_thread() reset the pointer before stopping the thread. 2) timeout_store() access 'mddev->thread' multiple times, null-ptr-deference can be triggered if 'mddev->thread' is reset in the middle. This patch factor out a helper to set timeout, the new helper always check if 'mddev->thread' is null first, so that problem 1 can be fixed. Now that this helper only access 'mddev->thread' once, but it's possible that 'mddev->thread' can be freed while this helper is still in progress, hence the problem is not fixed yet. Follow up patches will fix this by protecting md_thread with rcu. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230523021017.3048783-5-yukuai1@huaweicloud.com
2023-06-14md/bitmap: always wake up md_thread in timeout_storeYu Kuai1-3/+3
md_wakeup_thread() can handle the case that pass in md_thread is NULL, the only difference is that md_wakeup_thread() will be called when current timeout is 'MAX_SCHEDULE_TIMEOUT', this should not matter because timeout_store() is not hot path, and the daemon process is woke up more than demand from other context already. Prepare to factor out a helper to set timeout. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230523021017.3048783-4-yukuai1@huaweicloud.com
2023-06-14dm-raid: remove useless checking in raid_message()Yu Kuai1-2/+2
md_wakeup_thread() handle the case that pass in md_thread is NULL, there is no need to check this. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230523021017.3048783-3-yukuai1@huaweicloud.com
2023-06-14md: factor out a helper to wake up md_thread directlyYu Kuai1-8/+19
md_wakeup_thread() can't wakeup md_thread->tsk if md_thread->run is still in progress, and in some cases md_thread->tsk need to be woke up directly, like md_set_readonly() and do_md_stop(). Commit 9dfbdafda3b3 ("md: unlock mddev before reap sync_thread in action_store") introduce a new scenario where unregister sync_thread is not protected by 'reconfig_mutex', this can cause null-ptr-deference in theroy: t1: md_set_readonly t2: action_store md_unregister_thread // 'reconfig_mutex' is not held // 'reconfig_mutex' is held by caller if (mddev->sync_thread) thread = *threadp *threadp = NULL wake_up_process(mddev->sync_thread->tsk) // null-ptr-deference Fix this problem by factoring out a helper to wake up md_thread directly, so that 'sync_thread' won't be accessed multiple times from the reader side. This helper also prepare to protect md_thread with rcu. Noted that later patches is going to fix that unregister sync_thread is not protected by 'reconfig_mutex' from action_store(). Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230523021017.3048783-2-yukuai1@huaweicloud.com