summaryrefslogtreecommitdiff
path: root/drivers/md
AgeCommit message (Collapse)Author
2020-01-14dm thin: fix use-after-free in metadata_pre_commit_callbackMike Snitzer
dm-thin uses struct pool to hold the state of the pool. There may be multiple pool_c's pointing to a given pool, each pool_c represents a loaded target. pool_c's may be created and destroyed arbitrarily and the pool contains a reference count of pool_c's pointing to it. Since commit 694cfe7f31db3 ("dm thin: Flush data device before committing metadata") a pointer to pool_c is passed to dm_pool_register_pre_commit_callback and this function stores it in pmd->pre_commit_context. If this pool_c is freed, but pool is not (because there is another pool_c referencing it), we end up in a situation where pmd->pre_commit_context structure points to freed pool_c. It causes a crash in metadata_pre_commit_callback. Fix this by moving the dm_pool_register_pre_commit_callback() from pool_ctr() to pool_preresume(). This way the in-core thin-pool metadata is only ever armed with callback data whose lifetime matches the active thin-pool target. In should be noted that this fix preserves the ability to load a thin-pool table that uses a different data block device (that contains the same data) -- though it is unclear if that capability is still useful and/or needed. Fixes: 694cfe7f31db3 ("dm thin: Flush data device before committing metadata") Cc: stable@vger.kernel.org Reported-by: Zdenek Kabelac <zkabelac@redhat.com> Reported-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-01-14dm thin metadata: use pool locking at end of dm_pool_metadata_closeMike Snitzer
Ensure that the pool is locked during calls to __commit_transaction and __destroy_persistent_data_objects. Just being consistent with locking, but reality is dm_pool_metadata_close is called once pool is being destroyed so access to pool shouldn't be contended. Also, use pmd_write_lock_in_core rather than __pmd_write_lock in dm_pool_commit_metadata and rename __pmd_write_lock to pmd_write_lock_in_core -- there was no need for the alias. In addition, verify that the pool is locked in __commit_transaction(). Fixes: 873f258becca ("dm thin metadata: do not write metadata if no changes occurred") Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-01-14dm writecache: fix incorrect flush sequence when doing SSD mode commitMikulas Patocka
When committing state, the function writecache_flush does the following: 1. write metadata (writecache_commit_flushed) 2. flush disk cache (writecache_commit_flushed) 3. wait for data writes to complete (writecache_wait_for_ios) 4. increase superblock seq_count 5. write the superblock 6. flush disk cache It may happen that at step 3, when we wait for some write to finish, the disk may report the write as finished, but the write only hit the disk cache and it is not yet stored in persistent storage. At step 5 we write the superblock - it may happen that the superblock is written before the write that we waited for in step 3. If the machine crashes, it may result in incorrect data being returned after reboot. In order to fix the bug, we must swap steps 2 and 3 in the above sequence, so that we first wait for writes to complete and then flush the disk cache. Fixes: 48debafe4f2f ("dm: add writecache target") Cc: stable@vger.kernel.org # 4.18+ Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-01-14dm crypt: fix benbi IV constructor crash if used in authenticated modeMilan Broz
If benbi IV is used in AEAD construction, for example: cryptsetup luksFormat <device> --cipher twofish-xts-benbi --key-size 512 --integrity=hmac-sha256 the constructor uses wrong skcipher function and crashes: BUG: kernel NULL pointer dereference, address: 00000014 ... EIP: crypt_iv_benbi_ctr+0x15/0x70 [dm_crypt] Call Trace: ? crypt_subkey_size+0x20/0x20 [dm_crypt] crypt_ctr+0x567/0xfc0 [dm_crypt] dm_table_add_target+0x15f/0x340 [dm_mod] Fix this by properly using crypt_aead_blocksize() in this case. Fixes: ef43aa38063a6 ("dm crypt: add cryptographic data integrity protection (authenticated encryption)") Cc: stable@vger.kernel.org # v4.12+ Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=941051 Reported-by: Jerad Simpson <jbsimpson@gmail.com> Signed-off-by: Milan Broz <gmazyland@gmail.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-01-14dm crypt: Implement Elephant diffuser for Bitlocker compatibilityMilan Broz
Add experimental support for BitLocker encryption with CBC mode and additional Elephant diffuser. The mode was used in older Windows systems and it is provided mainly for compatibility reasons. The userspace support to activate these devices is being added to cryptsetup utility. Read-write activation of such a device is very simple, for example: echo <password> | cryptsetup bitlkOpen bitlk_image.img test The Elephant diffuser uses two rotations in opposite direction for data (Diffuser A and B) and also XOR operation with Sector key over the sector data; Sector key is derived from additional key data. The original public documentation is available here: http://download.microsoft.com/download/0/2/3/0238acaf-d3bf-4a6d-b3d6-0a0be4bbb36e/bitlockercipher200608.pdf The dm-crypt implementation is embedded to "elephant" IV (similar to tcw IV construction). Because we cannot modify original bio data for write (before encryption), an additional internal flag to pre-process data is added. Signed-off-by: Milan Broz <gmazyland@gmail.com> Reviewed-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-01-14dm space map common: fix to ensure new block isn't already in useJoe Thornber
The space-maps track the reference counts for disk blocks allocated by both the thin-provisioning and cache targets. There are variants for tracking metadata blocks and data blocks. Transactionality is implemented by never touching blocks from the previous transaction, so we can rollback in the event of a crash. When allocating a new block we need to ensure the block is free (has reference count of 0) in both the current and previous transaction. Prior to this fix we were doing this by searching for a free block in the previous transaction, and relying on a 'begin' counter to track where the last allocation in the current transaction was. This 'begin' field was not being updated in all code paths (eg, increment of a data block reference count due to breaking sharing of a neighbour block in the same btree leaf). This fix keeps the 'begin' field, but now it's just a hint to speed up the search. Instead the current transaction is searched for a free block, and then the old transaction is double checked to ensure it's free. Much simpler. This fixes reports of sm_disk_new_block()'s BUG_ON() triggering when DM thin-provisioning's snapshots are heavily used. Reported-by: Eric Wheeler <dm-devel@lists.ewheeler.net> Cc: stable@vger.kernel.org Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-01-13md/raid1: introduce wait_for_serializationGuoqing Jiang
Previously, we call check_and_add_serial when serialization is enabled for write IO, but it could allocate and free memory back and forth. Now, let's just get an element from memory pool with the new function, then insert node to rb tree if no collision happens. Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com> Signed-off-by: Song Liu <songliubraving@fb.com>
2020-01-13md/raid1: use bucket based mechanism for IO serializationGuoqing Jiang
Since raid1 had already used bucket based mechanism to reduce the conflict between write IO and resync IO, it is possible to speed up performance for io serialization with refer to the same mechanism. To align with the barrier bucket mechanism, we created arrays (with the same number of BARRIER_BUCKETS_NR) for spinlock, rb tree and waitqueue. Then we can reduce lock competition with multiple spinlocks, boost search performance with multiple rb trees and also reduce thundering herd problem with multiple waitqueues. Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com> Signed-off-by: Song Liu <songliubraving@fb.com>
2020-01-13md: introduce a new struct for IO serializationGuoqing Jiang
Obviously, IO serialization could cause the degradation of performance a lot. In order to reduce the degradation, so a rb interval tree is added in raid1 to speed up the check of collision. So, a rb root is needed in md_rdev, then abstract all the serialize related members to a new struct (serial_in_rdev), embed it into md_rdev. Of course, we need to free the struct if it is not needed anymore, so rdev/rdevs_uninit_serial are added accordingly. And they should be called when destroty memory pool or can't alloc memory. And we need to consider to call mddev_destroy_serial_pool in case serialize_policy/write-behind is disabled, bitmap is destroyed or in __md_stop_writes. Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com> Signed-off-by: Song Liu <songliubraving@fb.com>
2020-01-13md: don't destroy serial_info_pool if serialize_policy is trueGuoqing Jiang
The serial_info_pool is needed if array sets serialize_policy to true, so don't destroy it. Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com> Signed-off-by: Song Liu <songliubraving@fb.com>
2020-01-13raid1: serialize the overlap writeGuoqing Jiang
Before dispatch write bio, raid1 array which enables serialize_policy need to check if overlap exists between this bio and previous on-flying bios. If there is overlap, then it has to wait until the collision is disappeared. Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com> Signed-off-by: Song Liu <songliubraving@fb.com>
2020-01-13md: reorgnize mddev_create/destroy_serial_poolGuoqing Jiang
So far, IO serialization is used for two scenarios: 1. raid1 which enables write-behind mode, and there is rdev in the array which is multi-queue device and flaged with writemostly. 2. IO serialization is enabled or disabled by change serialize_policy. So introduce rdev_need_serial to check the first scenario. And for 1, IO serialization is enabled automatically while 2 is controlled manually. And it is possible that both scenarios are true, so for create serial pool, rdev/rdevs_init_serial should be separate from check if the pool existed or not. Then for destroy pool, we need to check if the pool is needed by other rdevs due to the first scenario. Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com> Signed-off-by: Song Liu <songliubraving@fb.com>
2020-01-13md: add serialize_policy sysfs node for raid1Guoqing Jiang
With the new sysfs node, we can use it to control if raid1 array wants io serialization or not. So mddev_create_serial_pool and mddev_destroy_serial_pool are called in serialize_policy_store to enable or disable the serialization. Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com> Signed-off-by: Song Liu <songliubraving@fb.com>
2020-01-13md: prepare for enable raid1 io serializationGuoqing Jiang
1. The related resources (spin_lock, list and waitqueue) are needed for address raid1 reorder overlap issue too, in this case, rdev is set to NULL for mddev_create/destroy_serial_pool which implies all rdevs need to handle these resources. And also add "is_suspend" to mddev_destroy_serial_pool since it will be called under suspended situation, which also makes both create and destroy pool have same arguments. 2. Introduce rdevs_init_serial which is called if raid1 io serialization is enabled since all rdevs need to init related stuffs. 3. rdev_init_serial and clear_bit(CollisionCheck, &rdev->flags) should be called between suspend and resume. No need to export mddev_create_serial_pool since it is only called in md-mod module. Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com> Signed-off-by: Song Liu <songliubraving@fb.com>
2020-01-13md: fix a typo s/creat/createGuoqing Jiang
It actually means create here, so fix the typo. Reported-by: Song Liu <liu.song.a23@gmail.com> Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com> Signed-off-by: Song Liu <songliubraving@fb.com>
2020-01-13md: rename wb stuffsGuoqing Jiang
Previously, wb_info_pool and wb_list stuffs are introduced to address potential data inconsistence issue for write behind device. Now rename them to serial related name, since the same mechanism will be used to address reorder overlap write issue for raid1. Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com> Signed-off-by: Song Liu <songliubraving@fb.com>
2020-01-13raid5: remove worker_cnt_per_group argument from alloc_thread_groupsGuoqing Jiang
We can use "cnt" directly to update conf->worker_cnt_per_group if alloc_thread_groups returns 0. Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com> Signed-off-by: Song Liu <songliubraving@fb.com>
2020-01-13md-bitmap: small cleanupsZhiqiang Liu
In md_bitmap_unplug, bitmap->storage.filemap is double checked. In md_bitmap_daemon_work, bitmap->storage.filemap should be checked before reference. Signed-off-by: Zhiqiang Liu <liuzhiqiang26@huawei.com> Signed-off-by: Song Liu <songliubraving@fb.com>
2020-01-07dm verity: don't prefetch hash blocks for already-verified dataxianrong.zhou
Try to skip prefetching hash blocks that won't be needed due to the "check_at_most_once" option being enabled and the corresponding data blocks already having been verified. Since prefetching operates on a range of data blocks, do this by just trimming the two ends of the range. This doesn't skip every unneeded hash block, since data blocks in the middle of the range could also be unneeded, and hash blocks are still prefetched in large clusters as controlled by dm_verity_prefetch_cluster. But it can still help a lot. In a test on Android Q launching 91 apps every 15s repeated 21 times, prefetching was only done for 447177/4776629 = 9.36% of data blocks. Tested-by: ruxian.feng <ruxian.feng@transsion.com> Co-developed-by: yuanjiong.gao <yuanjiong.gao@transsion.com> Signed-off-by: yuanjiong.gao <yuanjiong.gao@transsion.com> Signed-off-by: xianrong.zhou <xianrong.zhou@transsion.com> [EB: simplified the 'while' loops and improved the commit message] Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-01-07dm crypt: fix GFP flags passed to skcipher_request_alloc()Mikulas Patocka
GFP_KERNEL is not supposed to be or'd with GFP_NOFS (the result is equivalent to GFP_KERNEL). Also, we use GFP_NOIO instead of GFP_NOFS because we don't want any I/O being submitted in the direct reclaim path. Fixes: 39d13a1ac41d ("dm crypt: reuse eboiv skcipher for IV generation") Cc: stable@vger.kernel.org # v5.4+ Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-01-07dm thin metadata: Fix trivial math error in on-disk format documentationJeffle Xu
Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-01-07dm thin metadata: use true/false for bool variablezhengbin
Fixes coccicheck warning: drivers/md/dm-thin-metadata.c:814:3-14: WARNING: Assignment of 0/1 to bool variable drivers/md/dm-thin-metadata.c:1109:1-12: WARNING: Assignment of 0/1 to bool variable drivers/md/dm-thin-metadata.c:1621:1-12: WARNING: Assignment of 0/1 to bool variable drivers/md/dm-thin-metadata.c:1652:1-12: WARNING: Assignment of 0/1 to bool variable drivers/md/dm-thin-metadata.c:1706:1-12: WARNING: Assignment of 0/1 to bool variable Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: zhengbin <zhengbin13@huawei.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-01-07dm snapshot: use true/false for bool variablezhengbin
Fixes coccicheck warning: drivers/md/dm-snap.c:1064:3-18: WARNING: Assignment of 0/1 to bool variable drivers/md/dm-snap.c:1152:1-16: WARNING: Assignment of 0/1 to bool variable drivers/md/dm-snap.c:1317:1-16: WARNING: Assignment of 0/1 to bool variable Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: zhengbin <zhengbin13@huawei.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-01-07dm bio prison v2: use true/false for bool variablezhengbin
Fixes coccicheck warning: drivers/md/dm-bio-prison-v2.c:327:2-22: WARNING: Assignment of 0/1 to bool variable Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: zhengbin <zhengbin13@huawei.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-01-07dm mpath: use true/false for bool variablezhengbin
Fixes coccicheck warning: drivers/md/dm-mpath.c:1447:2-13: WARNING: Assignment of 0/1 to bool variable Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: zhengbin <zhengbin13@huawei.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-01-07dm zoned: support zone sizes smaller than 128MiBDmitry Fomichev
dm-zoned is observed to log failed kernel assertions and not work correctly when operating against a device with a zone size smaller than 128MiB (e.g. 32768 bits per 4K block). The reason is that the bitmap size per zone is calculated as zero with such a small zone size. Fix this problem and also make the code related to zone bitmap management be able to handle per zone bitmaps smaller than a single block. A dm-zoned-tools patch is required to properly format dm-zoned devices with zone sizes smaller than 128MiB. Fixes: 3b1a94c88b79 ("dm zoned: drive-managed zoned block device target") Cc: stable@vger.kernel.org Signed-off-by: Dmitry Fomichev <dmitry.fomichev@wdc.com> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-01-07dm raid: table line rebuild status fixesHeinz Mauelshagen
raid_status() wasn't emitting rebuild flags on the table line properly because the rdev number was not yet set properly; index raid component devices array directly to solve. Also fix wrong argument count on emitted table line caused by 1 too many rebuild/write_mostly argument and consider any journal_(dev|mode) pairs. Link: https://bugzilla.redhat.com/1782045 Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-01-07dm dust: change ret to r in dust_map_writeBryan Gurney
In the dust_map_write() function, change the return code variable "ret" to "r", to match the convention of the other device-mapper targets. Signed-off-by: Bryan Gurney <bgurney@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-12-13Merge tag 'for-linus-20191212' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block fixes from Jens Axboe: - stable fix for the bi_size overflow. Not a corruption issue, but a case wher we could merge but disallowed (Andreas) - NVMe pull request via Keith, with various fixes. - MD pull request from Song. - Merge window regression fix for the rq passthrough stats (Logan) - Remove unused blkcg_drain_queue() function (Guoqing) * tag 'for-linus-20191212' of git://git.kernel.dk/linux-block: blk-cgroup: remove blkcg_drain_queue block: fix NULL pointer dereference in account statistics with IDE md: make sure desc_nr less than MD_SB_DISKS md: raid1: check rdev before reference in raid1_sync_request func raid5: need to set STRIPE_HANDLE for batch head block: fix "check bi_size overflow before merge" nvme/pci: Fix read queue count nvme/pci Limit write queue sizes to possible cpus nvme/pci: Fix write and poll queue types nvme/pci: Remove last_cq_head nvme: Namepace identification descriptor list is optional nvme-fc: fix double-free scenarios on hw queues nvme: else following return is not needed nvme: add error message on mismatching controller ids nvme_fc: add module to ops template to allow module references nvmet-loop: Avoid preallocating big SGL for data nvme-fc: Avoid preallocating big SGL for data nvme-rdma: Avoid preallocating big SGL for data
2019-12-13Merge tag 'for-5.5/dm-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper fixes from Mike Snitzer: - Fix DM multipath by restoring full path selector functionality for bio-based configurations that don't haave a SCSI device handler. - Fix dm-btree removal to ensure non-root btree nodes have at least (max_entries / 3) entries. This resolves userspace thin_check utility's report of "too few entries in btree_node". - Fix both the DM thin-provisioning and dm-clone targets to properly flush the data device prior to metadata commit. This resolves the potential for inconsistency across a power loss event when the data device has a volatile writeback cache. - Small documentation fixes to dm-clone and dm-integrity. * tag 'for-5.5/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: docs: dm-integrity: remove reference to ARC4 dm thin: Flush data device before committing metadata dm thin metadata: Add support for a pre-commit callback dm clone: Flush destination device before committing metadata dm clone metadata: Use a two phase commit dm clone metadata: Track exact changes per transaction dm btree: increase rebalance threshold in __rebalance2() dm: add dm-clone to the documentation index dm mpath: remove harmful bio-based optimization
2019-12-11md: make sure desc_nr less than MD_SB_DISKSYufen Yu
For super_90_load, we need to make sure 'desc_nr' less than MD_SB_DISKS, avoiding invalid memory access of 'sb->disks'. Fixes: 228fc7d76db6 ("md: avoid invalid memory access for array sb->dev_roles") Signed-off-by: Yufen Yu <yuyufen@huawei.com> Signed-off-by: Song Liu <songliubraving@fb.com>
2019-12-11md: raid1: check rdev before reference in raid1_sync_request funcZhiqiang Liu
In raid1_sync_request func, rdev should be checked before reference. Signed-off-by: Zhiqiang Liu <liuzhiqiang26@huawei.com> Signed-off-by: Song Liu <songliubraving@fb.com>
2019-12-11raid5: need to set STRIPE_HANDLE for batch headGuoqing Jiang
With commit 6ce220dd2f8ea71d6afc29b9a7524c12e39f374a ("raid5: don't set STRIPE_HANDLE to stripe which is in batch list"), we don't want to set STRIPE_HANDLE flag for sh which is already in batch list. However, the stripe which is the head of batch list should set this flag, otherwise panic could happen inside init_stripe at BUG_ON(sh->batch_head), it is reproducible with raid5 on top of nvdimm devices per Xiao oberserved. Thanks for Xiao's effort to verify the change. Fixes: 6ce220dd2f8ea ("raid5: don't set STRIPE_HANDLE to stripe which is in batch list") Reported-by: Xiao Ni <xni@redhat.com> Tested-by: Xiao Ni <xni@redhat.com> Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com> Signed-off-by: Song Liu <songliubraving@fb.com>
2019-12-09treewide: Use sizeof_field() macroPankaj Bharadiya
Replace all the occurrences of FIELD_SIZEOF() with sizeof_field() except at places where these are defined. Later patches will remove the unused definition of FIELD_SIZEOF(). This patch is generated using following script: EXCLUDE_FILES="include/linux/stddef.h|include/linux/kernel.h" git grep -l -e "\bFIELD_SIZEOF\b" | while read file; do if [[ "$file" =~ $EXCLUDE_FILES ]]; then continue fi sed -i -e 's/\bFIELD_SIZEOF\b/sizeof_field/g' $file; done Signed-off-by: Pankaj Bharadiya <pankaj.laxminarayan.bharadiya@intel.com> Link: https://lore.kernel.org/r/20190924105839.110713-3-pankaj.laxminarayan.bharadiya@intel.com Co-developed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: David Miller <davem@davemloft.net> # for net
2019-12-06dm thin: Flush data device before committing metadataNikos Tsironis
The thin provisioning target maintains per thin device mappings that map virtual blocks to data blocks in the data device. When we write to a shared block, in case of internal snapshots, or provision a new block, in case of external snapshots, we copy the shared block to a new data block (COW), update the mapping for the relevant virtual block and then issue the write to the new data block. Suppose the data device has a volatile write-back cache and the following sequence of events occur: 1. We write to a shared block 2. A new data block is allocated 3. We copy the shared block to the new data block using kcopyd (COW) 4. We insert the new mapping for the virtual block in the btree for that thin device. 5. The commit timeout expires and we commit the metadata, that now includes the new mapping from step (4). 6. The system crashes and the data device's cache has not been flushed, meaning that the COWed data are lost. The next time we read that virtual block of the thin device we read it from the data block allocated in step (2), since the metadata have been successfully committed. The data are lost due to the crash, so we read garbage instead of the old, shared data. This has the following implications: 1. In case of writes to shared blocks, with size smaller than the pool's block size (which means we first copy the whole block and then issue the smaller write), we corrupt data that the user never touched. 2. In case of writes to shared blocks, with size equal to the device's logical block size, we fail to provide atomic sector writes. When the system recovers the user will read garbage from that sector instead of the old data or the new data. 3. Even for writes to shared blocks, with size equal to the pool's block size (overwrites), after the system recovers, the written sectors will contain garbage instead of a random mix of sectors containing either old data or new data, thus we fail again to provide atomic sectors writes. 4. Even when the user flushes the thin device, because we first commit the metadata and then pass down the flush, the same risk for corruption exists (if the system crashes after the metadata have been committed but before the flush is passed down to the data device.) The only case which is unaffected is that of writes with size equal to the pool's block size and with the FUA flag set. But, because FUA writes trigger metadata commits, this case can trigger the corruption indirectly. Moreover, apart from internal and external snapshots, the same issue exists for newly provisioned blocks, when block zeroing is enabled. After the system recovers the provisioned blocks might contain garbage instead of zeroes. To solve this and avoid the potential data corruption we flush the pool's data device **before** committing its metadata. This ensures that the data blocks of any newly inserted mappings are properly written to non-volatile storage and won't be lost in case of a crash. Cc: stable@vger.kernel.org Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com> Acked-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-12-05dm thin metadata: Add support for a pre-commit callbackNikos Tsironis
Add support for one pre-commit callback which is run right before the metadata are committed. This allows the thin provisioning target to run a callback before the metadata are committed and is required by the next commit. Cc: stable@vger.kernel.org Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com> Acked-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-12-05dm clone: Flush destination device before committing metadataNikos Tsironis
dm-clone maintains an on-disk bitmap which records which regions are valid in the destination device, i.e., which regions have already been hydrated, or have been written to directly, via user I/O. Setting a bit in the on-disk bitmap meas the corresponding region is valid in the destination device and we redirect all I/O regarding it to the destination device. Suppose the destination device has a volatile write-back cache and the following sequence of events occur: 1. A region gets hydrated, either through the background hydration or because it was written to directly, via user I/O. 2. The commit timeout expires and we commit the metadata, marking that region as valid in the destination device. 3. The system crashes and the destination device's cache has not been flushed, meaning the region's data are lost. The next time we read that region we read it from the destination device, since the metadata have been successfully committed, but the data are lost due to the crash, so we read garbage instead of the old data. This has several implications: 1. In case of background hydration or of writes with size smaller than the region size (which means we first copy the whole region and then issue the smaller write), we corrupt data that the user never touched. 2. In case of writes with size equal to the device's logical block size, we fail to provide atomic sector writes. When the system recovers the user will read garbage from the sector instead of the old data or the new data. 3. In case of writes without the FUA flag set, after the system recovers, the written sectors will contain garbage instead of a random mix of sectors containing either old data or new data, thus we fail again to provide atomic sector writes. 4. Even when the user flushes the dm-clone device, because we first commit the metadata and then pass down the flush, the same risk for corruption exists (if the system crashes after the metadata have been committed but before the flush is passed down). The only case which is unaffected is that of writes with size equal to the region size and with the FUA flag set. But, because FUA writes trigger metadata commits, this case can trigger the corruption indirectly. To solve this and avoid the potential data corruption we flush the destination device **before** committing the metadata. This ensures that any freshly hydrated regions, for which we commit the metadata, are properly written to non-volatile storage and won't be lost in case of a crash. Fixes: 7431b7835f55 ("dm: add clone target") Cc: stable@vger.kernel.org # v5.4+ Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-12-05dm clone metadata: Use a two phase commitNikos Tsironis
Split the metadata commit in two parts: 1. dm_clone_metadata_pre_commit(): Prepare the current transaction for committing. After this is called, all subsequent metadata updates, done through either dm_clone_set_region_hydrated() or dm_clone_cond_set_range(), will be part of the next transaction. 2. dm_clone_metadata_commit(): Actually commit the current transaction to disk and start a new transaction. This is required by the following commit. It allows dm-clone to flush the destination device after step (1) to ensure that all freshly hydrated regions, for which we are updating the metadata, are properly written to non-volatile storage and won't be lost in case of a crash. Fixes: 7431b7835f55 ("dm: add clone target") Cc: stable@vger.kernel.org # v5.4+ Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-12-05dm clone metadata: Track exact changes per transactionNikos Tsironis
Extend struct dirty_map with a second bitmap which tracks the exact regions that were hydrated during the current metadata transaction. Moreover, fix __flush_dmap() to only commit the metadata of the regions that were hydrated during the current transaction. This is required by the following commits to fix a data corruption bug. Fixes: 7431b7835f55 ("dm: add clone target") Cc: stable@vger.kernel.org # v5.4+ Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-12-05dm btree: increase rebalance threshold in __rebalance2()Hou Tao
We got the following warnings from thin_check during thin-pool setup: $ thin_check /dev/vdb examining superblock examining devices tree missing devices: [1, 84] too few entries in btree_node: 41, expected at least 42 (block 138, max_entries = 126) examining mapping tree The phenomenon is the number of entries in one node of details_info tree is less than (max_entries / 3). And it can be easily reproduced by the following procedures: $ new a thin pool $ presume the max entries of details_info tree is 126 $ new 127 thin devices (e.g. 1~127) to make the root node being full and then split $ remove the first 43 (e.g. 1~43) thin devices to make the children reblance repeatedly $ stop the thin pool $ thin_check The root cause is that the B-tree removal procedure in __rebalance2() doesn't guarantee the invariance: the minimal number of entries in non-root node should be >= (max_entries / 3). Simply fix the problem by increasing the rebalance threshold to make sure the number of entries in each child will be greater than or equal to (max_entries / 3 + 1), so no matter which child is used for removal, the number will still be valid. Cc: stable@vger.kernel.org Signed-off-by: Hou Tao <houtao1@huawei.com> Acked-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-12-03block: don't handle bio based drivers in blk_revalidate_disk_zonesChristoph Hellwig
bio based drivers only need to update q->nr_zones. Do that manually instead of overloading blk_revalidate_disk_zones to keep that function simpler for the next round of changes that will rely even more on the request based functionality. Reviewed-by: Javier González <javier@javigon.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-12-03block: simplify blkdev_nr_zonesChristoph Hellwig
Simplify the arguments to blkdev_nr_zones by passing a gendisk instead of the block_device and capacity. This also removes the need for __blkdev_nr_zones as all callers are outside the fast path and can deal with the additional branch. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-26dm mpath: remove harmful bio-based optimizationMike Snitzer
Removes the branching for edge-case where no SCSI device handler exists. The __map_bio_fast() method was far too limited, by only selecting a new pathgroup or path IFF there was a path failure, fix this be eliminating it in favor of __map_bio(). __map_bio()'s extra SCSI device handler specific MPATHF_PG_INIT_REQUIRED test is not in the fast path anyway. This change restores full path selector functionality for bio-based configurations that don't haave a SCSI device handler. But it should be noted that the path selectors do have an impact on performance for certain networks that are extremely fast (and don't require frequent switching). Fixes: 8d47e65948dd ("dm mpath: remove unnecessary NVMe branching in favor of scsi_dh checks") Cc: stable@vger.kernel.org Reported-by: Drew Hastings <dhastings@crucialwebhost.com> Suggested-by: Martin Wilck <mwilck@suse.de> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-11-25Merge tag 'for-5.5/dm-changes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper updates from Mike Snitzer: - Fix DM core to disallow stacking request-based DM on partitions. - Fix DM raid target to properly resync raidset even if bitmap needed additional pages. - Fix DM crypt performance regression due to use of WQ_HIGHPRI for the IO and crypt workqueues. - Fix DM integrity metadata layout that was aligned on 128K boundary rather than the intended 4K boundary (removes 124K of wasted space for each metadata block). - Improve the DM thin, cache and clone targets to use spin_lock_irq rather than spin_lock_irqsave where possible. - Fix DM thin single thread performance that was lost due to needless workqueue wakeups. - Fix DM zoned target performance that was lost due to excessive backing device checks. - Add ability to trigger write failure with the DM dust test target. - Fix whitespace indentation in drivers/md/Kconfig. - Various smalls fixes and cleanups (e.g. use struct_size, fix uninitialized variable, variable renames, etc). * tag 'for-5.5/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (22 commits) Revert "dm crypt: use WQ_HIGHPRI for the IO and crypt workqueues" dm: Fix Kconfig indentation dm thin: wakeup worker only when deferred bios exist dm integrity: fix excessive alignment of metadata runs dm raid: Remove unnecessary negation of a shift in raid10_format_to_md_layout dm zoned: reduce overhead of backing device checks dm dust: add limited write failure mode dm dust: change ret to r in dust_map_read and dust_map dm dust: change result vars to r dm cache: replace spin_lock_irqsave with spin_lock_irq dm bio prison: replace spin_lock_irqsave with spin_lock_irq dm thin: replace spin_lock_irqsave with spin_lock_irq dm clone: add bucket_lock_irq/bucket_unlock_irq helpers dm clone: replace spin_lock_irqsave with spin_lock_irq dm writecache: handle REQ_FUA dm writecache: fix uninitialized variable warning dm stripe: use struct_size() in kmalloc() dm raid: streamline rs_get_progress() and its raid_status() caller side dm raid: simplify rs_setup_recovery call chain dm raid: to ensure resynchronization, perform raid set grow in preresume ...
2019-11-25Merge tag 'for-5.5/zoned-20191122' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull zoned block device update from Jens Axboe: "Enhancements and improvements to the zoned device support" * tag 'for-5.5/zoned-20191122' of git://git.kernel.dk/linux-block: scsi: sd_zbc: Remove set but not used variable 'buflen' block: rework zone reporting scsi: sd_zbc: Cleanup sd_zbc_alloc_report_buffer() null_blk: Add zone_nr_conv to features null_blk: clean up report zones null_blk: clean up the block device operations block: Remove partition support for zoned block devices block: Simplify report zones execution block: cleanup the !zoned case in blk_revalidate_disk_zones block: Enhance blk_revalidate_disk_zones()
2019-11-25Merge tag 'for-5.5/drivers-20191121' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block driver updates from Jens Axboe: "Here are the main block driver updates for 5.5. Nothing major in here, mostly just fixes. This contains: - a set of bcache changes via Coly - MD changes from Song - loop unmap write-zeroes fix (Darrick) - spelling fixes (Geert) - zoned additions cleanups to null_blk/dm (Ajay) - allow null_blk online submit queue changes (Bart) - NVMe changes via Keith, nothing major here either" * tag 'for-5.5/drivers-20191121' of git://git.kernel.dk/linux-block: (56 commits) Revert "bcache: fix fifo index swapping condition in journal_pin_cmp()" drivers/md/raid5-ppl.c: use the new spelling of RWH_WRITE_LIFE_NOT_SET drivers/md/raid5.c: use the new spelling of RWH_WRITE_LIFE_NOT_SET bcache: don't export symbols bcache: remove the extra cflags for request.o bcache: at least try to shrink 1 node in bch_mca_scan() bcache: add idle_max_writeback_rate sysfs interface bcache: add code comments in bch_btree_leaf_dirty() bcache: fix deadlock in bcache_allocator bcache: add code comment bch_keylist_pop() and bch_keylist_pop_front() bcache: deleted code comments for dead code in bch_data_insert_keys() bcache: add more accurate error messages in read_super() bcache: fix static checker warning in bcache_device_free() bcache: fix a lost wake-up problem caused by mca_cannibalize_lock bcache: fix fifo index swapping condition in journal_pin_cmp() md/raid10: prevent access of uninitialized resync_pages offset md: avoid invalid memory access for array sb->dev_roles md/raid1: avoid soft lockup under high load null_blk: add zone open, close, and finish support dm: add zone open, close and finish support ...
2019-11-20Revert "dm crypt: use WQ_HIGHPRI for the IO and crypt workqueues"Mike Snitzer
This reverts commit a1b89132dc4f61071bdeaab92ea958e0953380a1. Revert required hand-patching due to subsequent changes that were applied since commit a1b89132dc4f61071bdeaab92ea958e0953380a1. Requires: ed0302e83098d ("dm crypt: make workqueue names device-specific") Cc: stable@vger.kernel.org Bug: https://bugzilla.kernel.org/show_bug.cgi?id=199857 Reported-by: Vito Caputo <vcaputo@pengaru.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-11-20dm: Fix Kconfig indentationKrzysztof Kozlowski
Adjust indentation from spaces to tab (+optional two spaces) as in coding style with command like: $ sed -e 's/^ /\t/' -i */Kconfig Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-11-18Revert "bcache: fix fifo index swapping condition in journal_pin_cmp()"Jens Axboe
Coly says: "Guoju Fang talked to me today, he told me this change was unnecessary and I was over-thought. Then I realize fifo_idx() uses a mask to handle the array index overflow condition, so the index swap in journal_pin_cmp() won't happen. And yes, Guoju and Kent are correct. Since you already applied this patch, can you please to remove this patch from your for-next branch? This single patch does not break thing, but it is unecessary at this moment." This reverts commit c0e0954e909c17b43d176ab219fc598964616ae6. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-18dm thin: wakeup worker only when deferred bios existJeffle Xu
Single thread fio test (read, bs=4k, ioengine=libaio, iodepth=128, numjobs=1) over dm-thin device has poor performance versus bare nvme device. Further investigation with perf indicates that queue_work_on() consumes over 20% CPU time when doing IO over dm-thin device. The call stack is as follows. - 40.57% thin_map + 22.07% queue_work_on + 9.95% dm_thin_find_block + 2.80% cell_defer_no_holder 1.91% inc_all_io_entry.isra.33.part.34 + 1.78% bio_detain.isra.35 In cell_defer_no_holder(), wakeup_worker() is always called, no matter whether the tc->deferred_bio_list list is empty or not. In single thread IO model, this list is most likely empty. So skip waking up worker thread if tc->deferred_bio_list list is empty. Single thread IO performance improves from 448 MiB/s to 646 MiB/s (+44%) once the needless wake_worker() calls are properly skipped. Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>