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We are seeing the following warning in raid10_handle_discard.
[ 695.110751] =============================
[ 695.131439] WARNING: suspicious RCU usage
[ 695.151389] 4.18.0-319.el8.x86_64+debug #1 Not tainted
[ 695.174413] -----------------------------
[ 695.192603] drivers/md/raid10.c:1776 suspicious
rcu_dereference_check() usage!
[ 695.225107] other info that might help us debug this:
[ 695.260940] rcu_scheduler_active = 2, debug_locks = 1
[ 695.290157] no locks held by mkfs.xfs/10186.
In the first loop of function raid10_handle_discard. It already
determines which disk need to handle discard request and add the
rdev reference count rdev->nr_pending. So the conf->mirrors will
not change until all bios come back from underlayer disks. It
doesn't need to use rcu_dereference to get rdev.
Cc: stable@vger.kernel.org
Fixes: d30588b273 ('md/raid10: improve raid10 discard request')
Signed-off-by: Xiao Ni <xni@redhat.com>
Acked-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Signed-off-by: Song Liu <songliubraving@fb.com>
There is no need to disable interrupts in bio_copy_block, and the local
only mappings helps to avoid any sort of problems with stray writes
into the bio data.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/20210727055646.118787-8-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
benefit both the DM thinp and cache targets.
- A few small DM kcopyd efficiency improvements.
- Significant zoned related block core, DM core and DM zoned target
changes that culminate with adding zoned append emulation (which is
required to properly fix DM crypt's zoned support).
- Various DM writecache target changes that improve efficiency. Adds
an optional "metadata_only" feature that only promotes bios flagged
with REQ_META. But the most significant improvement is writecache's
ability to pause writeback, for a confiurable time, if/when the
working set is larger than the cache (and the cache is full) -- this
ensures performance is no worse than the slower origin device.
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Merge tag 'for-5.14/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Pull device mapper updates from Mike Snitzer:
- Various DM persistent-data library improvements and fixes that
benefit both the DM thinp and cache targets.
- A few small DM kcopyd efficiency improvements.
- Significant zoned related block core, DM core and DM zoned target
changes that culminate with adding zoned append emulation (which is
required to properly fix DM crypt's zoned support).
- Various DM writecache target changes that improve efficiency. Adds an
optional "metadata_only" feature that only promotes bios flagged with
REQ_META. But the most significant improvement is writecache's
ability to pause writeback, for a confiurable time, if/when the
working set is larger than the cache (and the cache is full) -- this
ensures performance is no worse than the slower origin device.
* tag 'for-5.14/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (35 commits)
dm writecache: make writeback pause configurable
dm writecache: pause writeback if cache full and origin being written directly
dm io tracker: factor out IO tracker
dm btree remove: assign new_root only when removal succeeds
dm zone: fix dm_revalidate_zones() memory allocation
dm ps io affinity: remove redundant continue statement
dm writecache: add optional "metadata_only" parameter
dm writecache: add "cleaner" and "max_age" to Documentation
dm writecache: write at least 4k when committing
dm writecache: flush origin device when writing and cache is full
dm writecache: have ssd writeback wait if the kcopyd workqueue is busy
dm writecache: use list_move instead of list_del/list_add in writecache_writeback()
dm writecache: commit just one block, not a full page
dm writecache: remove unused gfp_t argument from wc_add_block()
dm crypt: Fix zoned block device support
dm: introduce zone append emulation
dm: rearrange core declarations for extended use from dm-zone.c
block: introduce BIO_ZONE_WRITE_LOCKED bio flag
block: introduce bio zone helpers
block: improve handling of all zones reset operation
...
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Merge tag 'for-5.14/drivers-2021-06-29' of git://git.kernel.dk/linux-block
Pull block driver updates from Jens Axboe:
"Pretty calm round, mostly just NVMe and a bit of MD:
- NVMe updates (via Christoph)
- improve the APST configuration algorithm (Alexey Bogoslavsky)
- look for StorageD3Enable on companion ACPI device
(Mario Limonciello)
- allow selecting the network interface for TCP connections
(Martin Belanger)
- misc cleanups (Amit Engel, Chaitanya Kulkarni, Colin Ian King,
Christoph)
- move the ACPI StorageD3 code to drivers/acpi/ and add quirks
for certain AMD CPUs (Mario Limonciello)
- zoned device support for nvmet (Chaitanya Kulkarni)
- fix the rules for changing the serial number in nvmet
(Noam Gottlieb)
- various small fixes and cleanups (Dan Carpenter, JK Kim,
Chaitanya Kulkarni, Hannes Reinecke, Wesley Sheng, Geert
Uytterhoeven, Daniel Wagner)
- MD updates (Via Song)
- iostats rewrite (Guoqing Jiang)
- raid5 lock contention optimization (Gal Ofri)
- Fall through warning fix (Gustavo)
- Misc fixes (Gustavo, Jiapeng)"
* tag 'for-5.14/drivers-2021-06-29' of git://git.kernel.dk/linux-block: (78 commits)
nvmet: use NVMET_MAX_NAMESPACES to set nn value
loop: Fix missing discard support when using LOOP_CONFIGURE
nvme.h: add missing nvme_lba_range_type endianness annotations
nvme: remove zeroout memset call for struct
nvme-pci: remove zeroout memset call for struct
nvmet: remove zeroout memset call for struct
nvmet: add ZBD over ZNS backend support
nvmet: add Command Set Identifier support
nvmet: add nvmet_req_bio put helper for backends
nvmet: add req cns error complete helper
block: export blk_next_bio()
nvmet: remove local variable
nvmet: use nvme status value directly
nvmet: use u32 type for the local variable nsid
nvmet: use u32 for nvmet_subsys max_nsid
nvmet: use req->cmd directly in file-ns fast path
nvmet: use req->cmd directly in bdev-ns fast path
nvmet: make ver stable once connection established
nvmet: allow mn change if subsys not discovered
nvmet: make sn stable once connection was established
...
Commit 95b88f4d71 ("dm writecache: pause
writeback if cache full and origin being written directly") introduced a
code that pauses cache flushing if we are issuing writes directly to the
origin.
Improve that initial commit by making the timeout code configurable
(via the option "pause_writeback"). Also change the default from 1s to
3s because it performed better.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Implementation reuses dm_io_tracker, that until now was only used by
dm-cache, to track if any writes were issued directly to the origin
(due to cache being full) within the last second. If so writeback is
paused for a second.
This change improves performance for when the cache is full and IO is
issued directly to the origin device (rather than through the cache).
Depends-on: d53f1fafec ("dm writecache: do direct write if the cache is full")
Suggested-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
remove_raw() in dm_btree_remove() may fail due to IO read error
(e.g. read the content of origin block fails during shadowing),
and the value of shadow_spine::root is uninitialized, but
the uninitialized value is still assign to new_root in the
end of dm_btree_remove().
For dm-thin, the value of pmd->details_root or pmd->root will become
an uninitialized value, so if trying to read details_info tree again
out-of-bound memory may occur as showed below:
general protection fault, probably for non-canonical address 0x3fdcb14c8d7520
CPU: 4 PID: 515 Comm: dmsetup Not tainted 5.13.0-rc6
Hardware name: QEMU Standard PC
RIP: 0010:metadata_ll_load_ie+0x14/0x30
Call Trace:
sm_metadata_count_is_more_than_one+0xb9/0xe0
dm_tm_shadow_block+0x52/0x1c0
shadow_step+0x59/0xf0
remove_raw+0xb2/0x170
dm_btree_remove+0xf4/0x1c0
dm_pool_delete_thin_device+0xc3/0x140
pool_message+0x218/0x2b0
target_message+0x251/0x290
ctl_ioctl+0x1c4/0x4d0
dm_ctl_ioctl+0xe/0x20
__x64_sys_ioctl+0x7b/0xb0
do_syscall_64+0x40/0xb0
entry_SYSCALL_64_after_hwframe+0x44/0xae
Fixing it by only assign new_root when removal succeeds
Signed-off-by: Hou Tao <houtao1@huawei.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Make sure that the zone write pointer offset array is allocated with a
vmalloc in dm_zone_revalidate_cb() by passing GFP_KERNEL gfp flag to
kvcalloc(). However, since we do not want to trigger IOs while
revalidating zones, change dm_revalidate_zones() to have the zone scan
done in GFP_NOIO context using memalloc_noio_save/restore calls.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: bb37d77239 ("dm: introduce zone append emulation")
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The continue statement at the end of a for-loop has no effect,
remove it.
Addresses-Coverity: ("Continue has no effect")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Add a "metadata_only" parameter that when present: only metadata is
promoted to the cache. This option improves performance for heavier
REQ_META workloads (e.g. device-mapper-test-suite's "git clone and
checkout" benchmark improves from 341s to 312s).
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
SSDs perform badly with sub-4k writes (because they perfrorm
read-modify-write internally), so make sure writecache writes at least
4k when committing.
Fixes: 991bd8d7bc ("dm writecache: commit just one block, not a full page")
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Change the type and name of task_struct::state. Drop the volatile and
shrink it to an 'unsigned int'. Rename it in order to find all uses
such that we can use READ_ONCE/WRITE_ONCE as appropriate.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Link: https://lore.kernel.org/r/20210611082838.550736351@infradead.org
Commit d53f1fafec ("dm writecache: do
direct write if the cache is full") changed dm-writecache, so that it
writes directly to the origin device if the cache is full.
Unfortunately, it doesn't forward flush requests to the origin device,
so that there is a bug where flushes are being ignored.
Fix this by adding missing flush forwarding.
For PMEM mode, we fix this bug by disabling direct writes to the origin
device, because it performs better.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Fixes: d53f1fafec ("dm writecache: do direct write if the cache is full")
Cc: stable@vger.kernel.org # v5.7+
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Make dm-writecache wait if the kcopyd workqueue is busy (as will
happen if waiting for page allocation or inside submit_bio).
This change improves performance of "mkfs.ext2" by approximately 20%
on one testbed.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
There is a lock contention on device_lock in read_one_chunk().
device_lock is taken to sync conf->active_aligned_reads and
conf->quiesce.
read_one_chunk() takes the lock, then waits for quiesce=0 (resumed)
before incrementing active_aligned_reads.
raid5_quiesce() takes the lock, sets quiesce=2 (in-progress), then waits
for active_aligned_reads to be zero before setting quiesce=1
(suspended).
Introduce a fast (lockless) path in read_one_chunk(): activate aligned
read without taking device_lock. In case quiesce starts while
activating the aligned-read in fast path, deactivate it and revert to
old behavior (take device_lock and wait for quiesce to finish).
Add smp store/load in raid5_quiesce()/read_one_chunk() respectively to
gaurantee that read_one_chunk() does not miss an ongoing quiesce.
My setups:
1. 8 local nvme drives (each up to 250k iops).
2. 8 ram disks (brd).
Each setup with raid6 (6+2), 1024 io threads on a 96 cpu-cores (48 per
socket) system. Record both iops and cpu spent on this contention with
rand-read-4k. Record bw with sequential-read-128k. Note: in most cases
cpu is still busy but due to "new" bottlenecks.
nvme:
| iops | cpu | bw
-----------------------------------------------
without patch | 1.6M | ~50% | 5.5GB/s
with patch | 2M (throttled) | 0% | 16GB/s (throttled)
ram (brd):
| iops | cpu | bw
-----------------------------------------------
without patch | 2M | ~80% | 24GB/s
with patch | 4M | 0% | 55GB/s
CC: Song Liu <song@kernel.org>
CC: Neil Brown <neilb@suse.de>
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Gal Ofri <gal.ofri@storing.io>
Signed-off-by: Song Liu <song@kernel.org>
Given it is not obvious for the error handling, let's try to add some
comments here to make it clear.
Signed-off-by: Guoqing Jiang <jiangguoqing@kylinos.cn>
Signed-off-by: Song Liu <song@kernel.org>
The bio_set (io_acct_set) is used by personalities to clone bio and
trace the timestamp of bio. Some personalities such as raid1/10 don't
need the bio_set, so add check to not create it unconditionally.
Also update the comment for md_account_bio to make it more clear.
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Guoqing Jiang <jiangguoqing@kylinos.cn>
Signed-off-by: Song Liu <song@kernel.org>
The attribute_group structs are never modified, they're only passed to
sysfs_create_group() and sysfs_remove_group(). Make them const to allow
the compiler to put them in read-only memory.
Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Signed-off-by: Song Liu <song@kernel.org>
Mark the three personalities (linear, fault and multipath) as deprecated
because:
1. people can use dm multipath or nvme multipath.
2. linear is already deprecated in MODULE_ALIAS.
3. no one actively using fault.
Signed-off-by: Guoqing Jiang <jiangguoqing@kylinos.cn>
Signed-off-by: Song Liu <song@kernel.org>
For raid10, we record the start time between split bio and clone bio,
and finish the accounting in the final endio.
Also introduce start_time in r10bio accordingly.
Signed-off-by: Guoqing Jiang <jiangguoqing@kylinos.cn>
Signed-off-by: Song Liu <song@kernel.org>
For raid1, we record the start time between split bio and clone bio,
and finish the accounting in the final endio.
Also introduce start_time in r1bio accordingly.
Signed-off-by: Guoqing Jiang <jiangguoqing@kylinos.cn>
Signed-off-by: Song Liu <song@kernel.org>
The caller of raid1_read_request could pass NULL or a valid pointer for
"struct r1bio *r1_bio", so it actually means whether r1_bio is existed
or not.
Signed-off-by: Guoqing Jiang <jiangguoqing@kylinos.cn>
Signed-off-by: Song Liu <song@kernel.org>
After enable io accounting, chunk read bio could be cloned twice which
is not good. To avoid such inefficiency, let's clone align_bio from
io_acct_set too, then we need only call md_account_bio in make_request
unconditionally.
Signed-off-by: Guoqing Jiang <jiangguoqing@kylinos.cn>
Signed-off-by: Song Liu <song@kernel.org>
We don't need to clone bio if the relevant region has badblock.
Signed-off-by: Guoqing Jiang <jiangguoqing@kylinos.cn>
Signed-off-by: Song Liu <song@kernel.org>
We introduce a new bioset (io_acct_set) for raid0 and raid5 since they
don't own clone infrastructure to accounting io. And the bioset is added
to mddev instead of to raid0 and raid5 layer, because with this way, we
can put common functions to md.h and reuse them in raid0 and raid5.
Also struct md_io_acct is added accordingly which includes io start_time,
the origin bio and cloned bio. Then we can call bio_{start,end}_io_acct
to get related io status.
Signed-off-by: Guoqing Jiang <jiangguoqing@kylinos.cn>
Signed-off-by: Song Liu <song@kernel.org>
The commit 41d2d848e5 ("md: improve io stats accounting") could cause
double fault problem per the report [1], and also it is not correct to
change ->bi_end_io if md don't own it, so let's revert it.
And io stats accounting will be replemented in later commits.
[1]. https://lore.kernel.org/linux-raid/3bf04253-3fad-434a-63a7-20214e38cf26@gmail.com/T/#t
Fixes: 41d2d848e5 ("md: improve io stats accounting")
Signed-off-by: Guoqing Jiang <jiangguoqing@kylinos.cn>
Signed-off-by: Song Liu <song@kernel.org>
Some architectures have pages larger than 4k and committing a full
page causes needless overhead.
Fix this by writing a single block when committing the superblock.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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Merge tag 'block-5.13-2021-06-12' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe:
"A few fixes that should go into 5.13:
- Fix a regression deadlock introduced in this release between open
and remove of a bdev (Christoph)
- Fix an async_xor md regression in this release (Xiao)
- Fix bcache oversized read issue (Coly)"
* tag 'block-5.13-2021-06-12' of git://git.kernel.dk/linux-block:
block: loop: fix deadlock between open and remove
async_xor: check src_offs is not NULL before updating it
bcache: avoid oversized read request in cache missing code path
bcache: remove bcache device self-defined readahead
Don't return the passed in request_queue but a normal error code, and
drop the elevator_init argument in favor of just calling elevator_init_mq
directly from dm-rq.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Link: https://lore.kernel.org/r/20210602065345.355274-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
In the cache missing code path of cached device, if a proper location
from the internal B+ tree is matched for a cache miss range, function
cached_dev_cache_miss() will be called in cache_lookup_fn() in the
following code block,
[code block 1]
526 unsigned int sectors = KEY_INODE(k) == s->iop.inode
527 ? min_t(uint64_t, INT_MAX,
528 KEY_START(k) - bio->bi_iter.bi_sector)
529 : INT_MAX;
530 int ret = s->d->cache_miss(b, s, bio, sectors);
Here s->d->cache_miss() is the call backfunction pointer initialized as
cached_dev_cache_miss(), the last parameter 'sectors' is an important
hint to calculate the size of read request to backing device of the
missing cache data.
Current calculation in above code block may generate oversized value of
'sectors', which consequently may trigger 2 different potential kernel
panics by BUG() or BUG_ON() as listed below,
1) BUG_ON() inside bch_btree_insert_key(),
[code block 2]
886 BUG_ON(b->ops->is_extents && !KEY_SIZE(k));
2) BUG() inside biovec_slab(),
[code block 3]
51 default:
52 BUG();
53 return NULL;
All the above panics are original from cached_dev_cache_miss() by the
oversized parameter 'sectors'.
Inside cached_dev_cache_miss(), parameter 'sectors' is used to calculate
the size of data read from backing device for the cache missing. This
size is stored in s->insert_bio_sectors by the following lines of code,
[code block 4]
909 s->insert_bio_sectors = min(sectors, bio_sectors(bio) + reada);
Then the actual key inserting to the internal B+ tree is generated and
stored in s->iop.replace_key by the following lines of code,
[code block 5]
911 s->iop.replace_key = KEY(s->iop.inode,
912 bio->bi_iter.bi_sector + s->insert_bio_sectors,
913 s->insert_bio_sectors);
The oversized parameter 'sectors' may trigger panic 1) by BUG_ON() from
the above code block.
And the bio sending to backing device for the missing data is allocated
with hint from s->insert_bio_sectors by the following lines of code,
[code block 6]
926 cache_bio = bio_alloc_bioset(GFP_NOWAIT,
927 DIV_ROUND_UP(s->insert_bio_sectors, PAGE_SECTORS),
928 &dc->disk.bio_split);
The oversized parameter 'sectors' may trigger panic 2) by BUG() from the
agove code block.
Now let me explain how the panics happen with the oversized 'sectors'.
In code block 5, replace_key is generated by macro KEY(). From the
definition of macro KEY(),
[code block 7]
71 #define KEY(inode, offset, size) \
72 ((struct bkey) { \
73 .high = (1ULL << 63) | ((__u64) (size) << 20) | (inode), \
74 .low = (offset) \
75 })
Here 'size' is 16bits width embedded in 64bits member 'high' of struct
bkey. But in code block 1, if "KEY_START(k) - bio->bi_iter.bi_sector" is
very probably to be larger than (1<<16) - 1, which makes the bkey size
calculation in code block 5 is overflowed. In one bug report the value
of parameter 'sectors' is 131072 (= 1 << 17), the overflowed 'sectors'
results the overflowed s->insert_bio_sectors in code block 4, then makes
size field of s->iop.replace_key to be 0 in code block 5. Then the 0-
sized s->iop.replace_key is inserted into the internal B+ tree as cache
missing check key (a special key to detect and avoid a racing between
normal write request and cache missing read request) as,
[code block 8]
915 ret = bch_btree_insert_check_key(b, &s->op, &s->iop.replace_key);
Then the 0-sized s->iop.replace_key as 3rd parameter triggers the bkey
size check BUG_ON() in code block 2, and causes the kernel panic 1).
Another kernel panic is from code block 6, is by the bvecs number
oversized value s->insert_bio_sectors from code block 4,
min(sectors, bio_sectors(bio) + reada)
There are two possibility for oversized reresult,
- bio_sectors(bio) is valid, but bio_sectors(bio) + reada is oversized.
- sectors < bio_sectors(bio) + reada, but sectors is oversized.
From a bug report the result of "DIV_ROUND_UP(s->insert_bio_sectors,
PAGE_SECTORS)" from code block 6 can be 344, 282, 946, 342 and many
other values which larther than BIO_MAX_VECS (a.k.a 256). When calling
bio_alloc_bioset() with such larger-than-256 value as the 2nd parameter,
this value will eventually be sent to biovec_slab() as parameter
'nr_vecs' in following code path,
bio_alloc_bioset() ==> bvec_alloc() ==> biovec_slab()
Because parameter 'nr_vecs' is larger-than-256 value, the panic by BUG()
in code block 3 is triggered inside biovec_slab().
From the above analysis, we know that the 4th parameter 'sector' sent
into cached_dev_cache_miss() may cause overflow in code block 5 and 6,
and finally cause kernel panic in code block 2 and 3. And if result of
bio_sectors(bio) + reada exceeds valid bvecs number, it may also trigger
kernel panic in code block 3 from code block 6.
Now the almost-useless readahead size for cache missing request back to
backing device is removed, this patch can fix the oversized issue with
more simpler method.
- add a local variable size_limit, set it by the minimum value from
the max bkey size and max bio bvecs number.
- set s->insert_bio_sectors by the minimum value from size_limit,
sectors, and the sectors size of bio.
- replace sectors by s->insert_bio_sectors to do bio_next_split.
By the above method with size_limit, s->insert_bio_sectors will never
result oversized replace_key size or bio bvecs number. And split bio
'miss' from bio_next_split() will always match the size of 'cache_bio',
that is the current maximum bio size we can sent to backing device for
fetching the cache missing data.
Current problmatic code can be partially found since Linux v3.13-rc1,
therefore all maintained stable kernels should try to apply this fix.
Reported-by: Alexander Ullrich <ealex1979@gmail.com>
Reported-by: Diego Ercolani <diego.ercolani@gmail.com>
Reported-by: Jan Szubiak <jan.szubiak@linuxpolska.pl>
Reported-by: Marco Rebhan <me@dblsaiko.net>
Reported-by: Matthias Ferdinand <bcache@mfedv.net>
Reported-by: Victor Westerhuis <victor@westerhu.is>
Reported-by: Vojtech Pavlik <vojtech@suse.cz>
Reported-and-tested-by: Rolf Fokkens <rolf@rolffokkens.nl>
Reported-and-tested-by: Thorsten Knabe <linux@thorsten-knabe.de>
Signed-off-by: Coly Li <colyli@suse.de>
Cc: stable@vger.kernel.org
Cc: Christoph Hellwig <hch@lst.de>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Nix <nix@esperi.org.uk>
Cc: Takashi Iwai <tiwai@suse.com>
Link: https://lore.kernel.org/r/20210607125052.21277-3-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
For read cache missing, bcache defines a readahead size for the read I/O
request to the backing device for the missing data. This readahead size
is initialized to 0, and almost no one uses it to avoid unnecessary read
amplifying onto backing device and write amplifying onto cache device.
Considering upper layer file system code has readahead logic allready
and works fine with readahead_cache_policy sysfile interface, we don't
have to keep bcache self-defined readahead anymore.
This patch removes the bcache self-defined readahead for cache missing
request for backing device, and the readahead sysfs file interfaces are
removed as well.
This is the preparation for next patch to fix potential kernel panic due
to oversized request in a simpler method.
Reported-by: Alexander Ullrich <ealex1979@gmail.com>
Reported-by: Diego Ercolani <diego.ercolani@gmail.com>
Reported-by: Jan Szubiak <jan.szubiak@linuxpolska.pl>
Reported-by: Marco Rebhan <me@dblsaiko.net>
Reported-by: Matthias Ferdinand <bcache@mfedv.net>
Reported-by: Victor Westerhuis <victor@westerhu.is>
Reported-by: Vojtech Pavlik <vojtech@suse.cz>
Reported-and-tested-by: Rolf Fokkens <rolf@rolffokkens.nl>
Reported-and-tested-by: Thorsten Knabe <linux@thorsten-knabe.de>
Signed-off-by: Coly Li <colyli@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Nix <nix@esperi.org.uk>
Cc: Takashi Iwai <tiwai@suse.com>
Link: https://lore.kernel.org/r/20210607125052.21277-2-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Zone append BIOs (REQ_OP_ZONE_APPEND) always specify the start sector
of the zone to be written instead of the actual sector location to
write. The write location is determined by the device and returned to
the host upon completion of the operation. This interface, while simple
and efficient for writing into sequential zones of a zoned block
device, is incompatible with the use of sector values to calculate a
cypher block IV. All data written in a zone end up using the same IV
values corresponding to the first sectors of the zone, but read
operation will specify any sector within the zone resulting in an IV
mismatch between encryption and decryption.
To solve this problem, report to DM core that zone append operations are
not supported. This result in the zone append operations being emulated
using regular write operations.
Reported-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
For zoned targets that cannot support zone append operations, implement
an emulation using regular write operations. If the original BIO
submitted by the user is a zone append operation, change its clone into
a regular write operation directed at the target zone write pointer
position.
To do so, an array of write pointer offsets (write pointer position
relative to the start of a zone) is added to struct mapped_device. All
operations that modify a sequential zone write pointer (writes, zone
reset, zone finish and zone append) are intersepted in __map_bio() and
processed using the new functions dm_zone_map_bio().
Detection of the target ability to natively support zone append
operations is done from dm_table_set_restrictions() by calling the
function dm_set_zones_restrictions(). A target that does not support
zone append operation, either by explicitly declaring it using the new
struct dm_target field zone_append_not_supported, or because the device
table contains a non-zoned device, has its mapped device marked with the
new flag DMF_ZONE_APPEND_EMULATED. The helper function
dm_emulate_zone_append() is introduced to test a mapped device for this
new flag.
Atomicity of the zones write pointer tracking and updates is done using
a zone write locking mechanism based on a bitmap. This is similar to
the block layer method but based on BIOs rather than struct request.
A zone write lock is taken in dm_zone_map_bio() for any clone BIO with
an operation type that changes the BIO target zone write pointer
position. The zone write lock is released if the clone BIO is failed
before submission or when dm_zone_endio() is called when the clone BIO
completes.
The zone write lock bitmap of the mapped device, together with a bitmap
indicating zone types (conv_zones_bitmap) and the write pointer offset
array (zwp_offset) are allocated and initialized with a full device zone
report in dm_set_zones_restrictions() using the function
dm_revalidate_zones().
For failed operations that may have modified a zone write pointer, the
zone write pointer offset is marked as invalid in dm_zone_endio().
Zones with an invalid write pointer offset are checked and the write
pointer updated using an internal report zone operation when the
faulty zone is accessed again by the user.
All functions added for this emulation have a minimal overhead for
zoned targets natively supporting zone append operations. Regular
device targets are also not affected. The added code also does not
impact builds with CONFIG_BLK_DEV_ZONED disabled by stubbing out all
dm zone related functions.
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Move the definitions of struct dm_target_io, struct dm_io and the bits
of the flags field of struct mapped_device from dm.c to dm-core.h to
make them usable from dm-zone.c. For the same reason, declare
dec_pending() in dm-core.h after renaming it to dm_io_dec_pending().
And for symmetry of the function names, introduce the inline helper
dm_io_inc_pending() instead of directly using atomic_inc() calls.
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
A target map method requesting the requeue of a bio with
DM_MAPIO_REQUEUE or completing it with DM_ENDIO_REQUEUE can cause
unaligned write errors if the bio is a write operation targeting a
sequential zone. If a zoned target request such a requeue, warn about
it and kill the IO.
The function dm_is_zone_write() is introduced to detect write operations
to zoned targets.
This change does not affect the target drivers supporting zoned devices
and exposing a zoned device, namely dm-crypt, dm-linear and dm-flakey as
none of these targets ever request a requeue.
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
To simplify the implementation of the report_zones operation of a zoned
target, introduce the function dm_report_zones() to set a target
mapping start sector in struct dm_report_zones_args and call
blkdev_report_zones(). This new function is exported and the report
zones callback function dm_report_zones_cb() is not.
dm-linear, dm-flakey and dm-crypt are modified to use dm_report_zones().
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Move core and table code used for zoned targets and conditionally
defined with #ifdef CONFIG_BLK_DEV_ZONED to the new file dm-zone.c.
This file is conditionally compiled depending on CONFIG_BLK_DEV_ZONED.
The small helper dm_set_zones_restrictions() is introduced to
initialize a mapped device request queue zone attributes in
dm_table_set_restrictions().
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
In device_area_is_invalid(), use bdev_is_zoned() instead of open
coding the test on the zoned model returned by bdev_zoned_model().
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Fix dm_accept_partial_bio() to actually check that zone management
commands are not passed as explained in the function documentation
comment. Also, since a zone append operation cannot be split, add
REQ_OP_ZONE_APPEND as a forbidden command.
White lines are added around the group of BUG_ON() calls to make the
code more legible.
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The dm-zoned target cannot support zoned block devices with zones that
have a capacity smaller than the zone size (e.g. NVMe zoned namespaces)
due to the current chunk zone mapping implementation as it is assumed
that zones and chunks have the same size with all blocks usable.
If a zoned drive is found to have zones with a capacity different from
the zone size, fail the target initialization.
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Cc: stable@vger.kernel.org # v5.9+
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The only usage of dm_ksm_ll_ops is to make a copy of it to the ksm_ll_ops
field in the blk_keyslot_manager struct. Make it const to allow the
compiler to put it in read-only memory.
Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
If the DM device is suspended, interrupt the writeback sequence so
that there is no excessive suspend delay.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
If dm-writecache overwrites existing cached data, it splits the
incoming bio into many block-sized bios. The I/O scheduler does merge
these bios into one large request but this needless splitting and
merging causes performance degradation.
Fix this by avoiding bio splitting if the cache target area that is
being overwritten is contiguous.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The functions "pop", "push_head", "do_work" can only be called from
process context. Therefore, replace spin_lock_irq{save,restore} with
spin_{lock,unlock}_irq.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The functions set_bit and clear_bit are atomic. We don't need
atomicity when making flags for dm-kcopyd. So, change them to direct
manipulation of the flags.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
