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path: root/drivers/md/dm-zoned-target.c
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2019-08-26dm zoned: fix invalid memory accessMikulas Patocka1-2/+0
Commit 75d66ffb48efb30f2dd42f041ba8b39c5b2bd115 ("dm zoned: properly handle backing device failure") triggers a coverity warning: *** CID 1452808: Memory - illegal accesses (USE_AFTER_FREE) /drivers/md/dm-zoned-target.c: 137 in dmz_submit_bio() 131 clone->bi_private = bioctx; 132 133 bio_advance(bio, clone->bi_iter.bi_size); 134 135 refcount_inc(&bioctx->ref); 136 generic_make_request(clone); >>> CID 1452808: Memory - illegal accesses (USE_AFTER_FREE) >>> Dereferencing freed pointer "clone". 137 if (clone->bi_status == BLK_STS_IOERR) 138 return -EIO; 139 140 if (bio_op(bio) == REQ_OP_WRITE && dmz_is_seq(zone)) 141 zone->wp_block += nr_blocks; 142 The "clone" bio may be processed and freed before the check "clone->bi_status == BLK_STS_IOERR" - so this check can access invalid memory. Fixes: 75d66ffb48efb3 ("dm zoned: properly handle backing device failure") Cc: stable@vger.kernel.org Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-08-15dm zoned: add SPDX license identifiersDmitry Fomichev1-0/+1
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>
2019-08-15dm zoned: properly handle backing device failureDmitry Fomichev1-2/+43
dm-zoned is observed to lock up or livelock in case of hardware failure or some misconfiguration of the backing zoned device. This patch adds a new dm-zoned target function that checks the status of the backing device. If the request queue of the backing device is found to be in dying state or the SCSI backing device enters offline state, the health check code sets a dm-zoned target flag prompting all further incoming I/O to be rejected. In order to detect backing device failures timely, this new function is called in the request mapping path, at the beginning of every reclaim run and before performing any metadata I/O. The proper way out of this situation is to do dmsetup remove <dm-zoned target> and recreate the target when the problem with the backing device is resolved. 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>
2019-08-15dm zoned: improve error handling in i/o map codeDmitry Fomichev1-6/+16
Some errors are ignored in the I/O path during queueing chunks for processing by chunk works. Since at least these errors are transient in nature, it should be possible to retry the failed incoming commands. The fix - Errors that can happen while queueing chunks are carried upwards to the main mapping function and it now returns DM_MAPIO_REQUEUE for any incoming requests that can not be properly queued. Error logging/debug messages are added where needed. 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>
2019-04-18dm zoned: Silence a static checker warningDan Carpenter1-1/+2
My static checker complains about this line from dmz_get_zoned_device() aligned_capacity = dev->capacity & ~(blk_queue_zone_sectors(q) - 1); The problem is that "aligned_capacity" and "dev->capacity" are sector_t type (which is a u64 under most configs) but blk_queue_zone_sectors(q) returns a u32 so the higher 32 bits in aligned_capacity are cleared to zero. This patch adds a cast to address the issue. Fixes: 114e025968b5 ("dm zoned: ignore last smaller runt zone") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-02-20dm: eliminate 'split_discard_bios' flag from DM target interfaceMike Snitzer1-1/+0
There is no need to have DM core split discards on behalf of a DM target now that blk_queue_split() handles splitting discards based on the queue_limits. A DM target just needs to set max_discard_sectors, discard_granularity, etc, in queue_limits. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-12-07dm zoned: Fix target BIO completion handlingDamien Le Moal1-84/+38
struct bioctx includes the ref refcount_t to track the number of I/O fragments used to process a target BIO as well as ensure that the zone of the BIO is kept in the active state throughout the lifetime of the BIO. However, since decrementing of this reference count is done in the target .end_io method, the function bio_endio() must be called multiple times for read and write target BIOs, which causes problems with the value of the __bi_remaining struct bio field for chained BIOs (e.g. the clone BIO passed by dm core is large and splits into fragments by the block layer), resulting in incorrect values and inconsistencies with the BIO_CHAIN flag setting. This is turn triggers the BUG_ON() call: BUG_ON(atomic_read(&bio->__bi_remaining) <= 0); in bio_remaining_done() called from bio_endio(). Fix this ensuring that bio_endio() is called only once for any target BIO by always using internal clone BIOs for processing any read or write target BIO. This allows reference counting using the target BIO context counter to trigger the target BIO completion bio_endio() call once all data, metadata and other zone work triggered by the BIO complete. Overall, this simplifies the code too as the target .end_io becomes unnecessary and differences between read and write BIO issuing and completion processing disappear. Fixes: 3b1a94c88b79 ("dm zoned: drive-managed zoned block device target") Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-10-26Merge tag 'for-4.20/dm-changes' of ↵Linus Torvalds1-10/+10
git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper updates from Mike Snitzer: - The biggest change this cycle is to remove support for the legacy IO path (.request_fn) from request-based DM. Jens has already started preparing for complete removal of the legacy IO path in 4.21 but this earlier removal of support from DM has been coordinated with Jens (as evidenced by the commit being attributed to him). Making request-based DM exclussively blk-mq only cleans up that portion of DM core quite nicely. - Convert the thinp and zoned targets over to using refcount_t where applicable. - A couple fixes to the DM zoned target for refcounting and other races buried in the implementation of metadata block creation and use. - Small cleanups to remove redundant unlikely() around a couple WARN_ON_ONCE(). - Simplify how dm-ioctl copies from userspace, eliminating some potential for a malicious user trying to change the executed ioctl after its processing has begun. - Tweaked DM crypt target to use the DM device name when naming the various workqueues created for a particular DM crypt device (makes the N workqueues for a DM crypt device more easily understood and enhances user's accounting capabilities at a glance via "ps") - Small fixup to remove dead branch in DM writecache's memory_entry(). * tag 'for-4.20/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm writecache: remove disabled code in memory_entry() dm zoned: fix various dmz_get_mblock() issues dm zoned: fix metadata block ref counting dm raid: avoid bitmap with raid4/5/6 journal device dm crypt: make workqueue names device-specific dm: add dm_table_device_name() dm ioctl: harden copy_params()'s copy_from_user() from malicious users dm: remove unnecessary unlikely() around WARN_ON_ONCE() dm zoned: target: use refcount_t for dm zoned reference counters dm thin: use refcount_t for thin_c reference counting dm table: require that request-based DM be layered on blk-mq devices dm: rename DM_TYPE_MQ_REQUEST_BASED to DM_TYPE_REQUEST_BASED dm: remove legacy request-based IO path
2018-10-25block: Introduce blkdev_nr_zones() helperDamien Le Moal1-2/+1
Introduce the blkdev_nr_zones() helper function to get the total number of zones of a zoned block device. This number is always 0 for a regular block device (q->limits.zoned == BLK_ZONED_NONE case). Replace hard-coded number of zones calculation in dmz_get_zoned_device() with a call to this helper. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-10-16dm zoned: target: use refcount_t for dm zoned reference countersJohn Pittman1-10/+10
The API surrounding refcount_t should be used in place of atomic_t when variables are being used as reference counters. This API can prevent issues such as counter overflows and use-after-free conditions. Within the dm zoned target stack, the atomic_t API is used for bioctx->ref and cw->refcount. Change these to use refcount_t, avoiding the issues mentioned. Signed-off-by: John Pittman <jpittman@redhat.com> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Tested-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-06-22dm zoned: avoid triggering reclaim from inside dmz_map()Bart Van Assche1-1/+1
This patch avoids that lockdep reports the following: ====================================================== WARNING: possible circular locking dependency detected 4.18.0-rc1 #62 Not tainted ------------------------------------------------------ kswapd0/84 is trying to acquire lock: 00000000c313516d (&xfs_nondir_ilock_class){++++}, at: xfs_free_eofblocks+0xa2/0x1e0 but task is already holding lock: 00000000591c83ae (fs_reclaim){+.+.}, at: __fs_reclaim_acquire+0x5/0x30 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (fs_reclaim){+.+.}: kmem_cache_alloc+0x2c/0x2b0 radix_tree_node_alloc.constprop.19+0x3d/0xc0 __radix_tree_create+0x161/0x1c0 __radix_tree_insert+0x45/0x210 dmz_map+0x245/0x2d0 [dm_zoned] __map_bio+0x40/0x260 __split_and_process_non_flush+0x116/0x220 __split_and_process_bio+0x81/0x180 __dm_make_request.isra.32+0x5a/0x100 generic_make_request+0x36e/0x690 submit_bio+0x6c/0x140 mpage_readpages+0x19e/0x1f0 read_pages+0x6d/0x1b0 __do_page_cache_readahead+0x21b/0x2d0 force_page_cache_readahead+0xc4/0x100 generic_file_read_iter+0x7c6/0xd20 __vfs_read+0x102/0x180 vfs_read+0x9b/0x140 ksys_read+0x55/0xc0 do_syscall_64+0x5a/0x1f0 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #1 (&dmz->chunk_lock){+.+.}: dmz_map+0x133/0x2d0 [dm_zoned] __map_bio+0x40/0x260 __split_and_process_non_flush+0x116/0x220 __split_and_process_bio+0x81/0x180 __dm_make_request.isra.32+0x5a/0x100 generic_make_request+0x36e/0x690 submit_bio+0x6c/0x140 _xfs_buf_ioapply+0x31c/0x590 xfs_buf_submit_wait+0x73/0x520 xfs_buf_read_map+0x134/0x2f0 xfs_trans_read_buf_map+0xc3/0x580 xfs_read_agf+0xa5/0x1e0 xfs_alloc_read_agf+0x59/0x2b0 xfs_alloc_pagf_init+0x27/0x60 xfs_bmap_longest_free_extent+0x43/0xb0 xfs_bmap_btalloc_nullfb+0x7f/0xf0 xfs_bmap_btalloc+0x428/0x7c0 xfs_bmapi_write+0x598/0xcc0 xfs_iomap_write_allocate+0x15a/0x330 xfs_map_blocks+0x1cf/0x3f0 xfs_do_writepage+0x15f/0x7b0 write_cache_pages+0x1ca/0x540 xfs_vm_writepages+0x65/0xa0 do_writepages+0x48/0xf0 __writeback_single_inode+0x58/0x730 writeback_sb_inodes+0x249/0x5c0 wb_writeback+0x11e/0x550 wb_workfn+0xa3/0x670 process_one_work+0x228/0x670 worker_thread+0x3c/0x390 kthread+0x11c/0x140 ret_from_fork+0x3a/0x50 -> #0 (&xfs_nondir_ilock_class){++++}: down_read_nested+0x43/0x70 xfs_free_eofblocks+0xa2/0x1e0 xfs_fs_destroy_inode+0xac/0x270 dispose_list+0x51/0x80 prune_icache_sb+0x52/0x70 super_cache_scan+0x127/0x1a0 shrink_slab.part.47+0x1bd/0x590 shrink_node+0x3b5/0x470 balance_pgdat+0x158/0x3b0 kswapd+0x1ba/0x600 kthread+0x11c/0x140 ret_from_fork+0x3a/0x50 other info that might help us debug this: Chain exists of: &xfs_nondir_ilock_class --> &dmz->chunk_lock --> fs_reclaim Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(fs_reclaim); lock(&dmz->chunk_lock); lock(fs_reclaim); lock(&xfs_nondir_ilock_class); *** DEADLOCK *** 3 locks held by kswapd0/84: #0: 00000000591c83ae (fs_reclaim){+.+.}, at: __fs_reclaim_acquire+0x5/0x30 #1: 000000000f8208f5 (shrinker_rwsem){++++}, at: shrink_slab.part.47+0x3f/0x590 #2: 00000000cacefa54 (&type->s_umount_key#43){.+.+}, at: trylock_super+0x16/0x50 stack backtrace: CPU: 7 PID: 84 Comm: kswapd0 Not tainted 4.18.0-rc1 #62 Hardware name: Supermicro Super Server/X10SRL-F, BIOS 2.0 12/17/2015 Call Trace: dump_stack+0x85/0xcb print_circular_bug.isra.36+0x1ce/0x1db __lock_acquire+0x124e/0x1310 lock_acquire+0x9f/0x1f0 down_read_nested+0x43/0x70 xfs_free_eofblocks+0xa2/0x1e0 xfs_fs_destroy_inode+0xac/0x270 dispose_list+0x51/0x80 prune_icache_sb+0x52/0x70 super_cache_scan+0x127/0x1a0 shrink_slab.part.47+0x1bd/0x590 shrink_node+0x3b5/0x470 balance_pgdat+0x158/0x3b0 kswapd+0x1ba/0x600 kthread+0x11c/0x140 ret_from_fork+0x3a/0x50 Reported-by: Masato Suzuki <masato.suzuki@wdc.com> Fixes: 4218a9554653 ("dm zoned: use GFP_NOIO in I/O path") Cc: <stable@vger.kernel.org> Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-06-08dm: adjust structure members to improve alignmentMike Snitzer1-1/+1
Eliminate most holes in DM data structures that were modified by commit 6f1c819c21 ("dm: convert to bioset_init()/mempool_init()"). Also prevent structure members from unnecessarily spanning cache lines. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-05-30dm: convert to bioset_init()/mempool_init()Kent Overstreet1-7/+6
Convert dm to embedded bio sets. Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-04-04dm: remove fmode_t argument from .prepare_ioctl hookMike Snitzer1-2/+1
Use the fmode_t that is passed to dm_blk_ioctl() rather than inconsistently (varies across targets) drop it on the floor by overriding it with the fmode_t stored in 'struct dm_dev'. All the persistent reservation functions weren't using the fmode_t they got back from .prepare_ioctl so remove them. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-01-17dm: backfill missing calls to mutex_destroy()Mike Snitzer1-0/+3
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-11-10dm zoned: ignore last smaller runt zoneDamien Le Moal1-4/+9
The SCSI layer allows ZBC drives to have a smaller last runt zone. For such a device, specifying the entire capacity for a dm-zoned target table entry fails because the specified capacity is not aligned on a device zone size indicated in the request queue structure of the device. Fix this problem by ignoring the last runt zone in the entry length when seting up the dm-zoned target (ctr method) and when iterating table entries of the target (iterate_devices method). This allows dm-zoned users to still easily setup a target using the entire device capacity (as mandated by dm-zoned) or the aligned capacity excluding the last runt zone. While at it, replace direct references to the device queue chunk_sectors limit with calls to the accessor blk_queue_zone_sectors(). Reported-by: Peter Desnoyers <pjd@ccs.neu.edu> Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-08-23block: replace bi_bdev with a gendisk pointer and partitions indexChristoph Hellwig1-2/+2
This way we don't need a block_device structure to submit I/O. The block_device has different life time rules from the gendisk and request_queue and is usually only available when the block device node is open. Other callers need to explicitly create one (e.g. the lightnvm passthrough code, or the new nvme multipathing code). For the actual I/O path all that we need is the gendisk, which exists once per block device. But given that the block layer also does partition remapping we additionally need a partition index, which is used for said remapping in generic_make_request. Note that all the block drivers generally want request_queue or sometimes the gendisk, so this removes a layer of indirection all over the stack. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-07-26dm zoned: use GFP_NOIO in I/O pathDamien Le Moal1-2/+2
Use GFP_NOIO for memory allocations in the I/O path. Other memory allocations in the initialization path can use GFP_KERNEL. Reported-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-07-25dm zoned: remove test for impossible REQ_OP_FLUSH conditionsMikulas Patocka1-2/+2
The value REQ_OP_FLUSH is only used by the block code for request-based devices. Remove the tests for REQ_OP_FLUSH from the bio-based dm-zoned-target. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-06-19dm zoned: drive-managed zoned block device targetDamien Le Moal1-0/+967
The dm-zoned device mapper target provides transparent write access to zoned block devices (ZBC and ZAC compliant block devices). dm-zoned hides to the device user (a file system or an application doing raw block device accesses) any constraint imposed on write requests by the device, equivalent to a drive-managed zoned block device model. Write requests are processed using a combination of on-disk buffering using the device conventional zones and direct in-place processing for requests aligned to a zone sequential write pointer position. A background reclaim process implemented using dm_kcopyd_copy ensures that conventional zones are always available for executing unaligned write requests. The reclaim process overhead is minimized by managing buffer zones in a least-recently-written order and first targeting the oldest buffer zones. Doing so, blocks under regular write access (such as metadata blocks of a file system) remain stored in conventional zones, resulting in no apparent overhead. dm-zoned implementation focus on simplicity and on minimizing overhead (CPU, memory and storage overhead). For a 14TB host-managed disk with 256 MB zones, dm-zoned memory usage per disk instance is at most about 3 MB and as little as 5 zones will be used internally for storing metadata and performing buffer zone reclaim operations. This is achieved using zone level indirection rather than a full block indirection system for managing block movement between zones. dm-zoned primary target is host-managed zoned block devices but it can also be used with host-aware device models to mitigate potential device-side performance degradation due to excessive random writing. Zoned block devices can be formatted and checked for use with the dm-zoned target using the dmzadm utility available at: https://github.com/hgst/dm-zoned-tools Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> [Mike Snitzer partly refactored Damien's original work to cleanup the code] Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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