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[ Upstream commit 1e46ed947ec658f89f1a910d880cd05e42d3763e ]
1. LINE#1794 - LINE#1887 is some codes about function of
bch_cache_set_alloc().
2. LINE#2078 - LINE#2142 is some codes about function of
register_cache_set().
3. register_cache_set() will call bch_cache_set_alloc() in LINE#2098.
1794 struct cache_set *bch_cache_set_alloc(struct cache_sb *sb)
1795 {
...
1860 if (!(c->devices = kcalloc(c->nr_uuids, sizeof(void *), GFP_KERNEL)) ||
1861 mempool_init_slab_pool(&c->search, 32, bch_search_cache) ||
1862 mempool_init_kmalloc_pool(&c->bio_meta, 2,
1863 sizeof(struct bbio) + sizeof(struct bio_vec) *
1864 bucket_pages(c)) ||
1865 mempool_init_kmalloc_pool(&c->fill_iter, 1, iter_size) ||
1866 bioset_init(&c->bio_split, 4, offsetof(struct bbio, bio),
1867 BIOSET_NEED_BVECS|BIOSET_NEED_RESCUER) ||
1868 !(c->uuids = alloc_bucket_pages(GFP_KERNEL, c)) ||
1869 !(c->moving_gc_wq = alloc_workqueue("bcache_gc",
1870 WQ_MEM_RECLAIM, 0)) ||
1871 bch_journal_alloc(c) ||
1872 bch_btree_cache_alloc(c) ||
1873 bch_open_buckets_alloc(c) ||
1874 bch_bset_sort_state_init(&c->sort, ilog2(c->btree_pages)))
1875 goto err;
^^^^^^^^
1876
...
1883 return c;
1884 err:
1885 bch_cache_set_unregister(c);
^^^^^^^^^^^^^^^^^^^^^^^^^^^
1886 return NULL;
1887 }
...
2078 static const char *register_cache_set(struct cache *ca)
2079 {
...
2098 c = bch_cache_set_alloc(&ca->sb);
2099 if (!c)
2100 return err;
^^^^^^^^^^
...
2128 ca->set = c;
2129 ca->set->cache[ca->sb.nr_this_dev] = ca;
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...
2138 return NULL;
2139 err:
2140 bch_cache_set_unregister(c);
2141 return err;
2142 }
(1) If LINE#1860 - LINE#1874 is true, then do 'goto err'(LINE#1875) and
call bch_cache_set_unregister()(LINE#1885).
(2) As (1) return NULL(LINE#1886), LINE#2098 - LINE#2100 would return.
(3) As (2) has returned, LINE#2128 - LINE#2129 would do *not* give the
value to c->cache[], it means that c->cache[] is NULL.
LINE#1624 - LINE#1665 is some codes about function of cache_set_flush().
As (1), in LINE#1885 call
bch_cache_set_unregister()
---> bch_cache_set_stop()
---> closure_queue()
-.-> cache_set_flush() (as below LINE#1624)
1624 static void cache_set_flush(struct closure *cl)
1625 {
...
1654 for_each_cache(ca, c, i)
1655 if (ca->alloc_thread)
^^
1656 kthread_stop(ca->alloc_thread);
...
1665 }
(4) In LINE#1655 ca is NULL(see (3)) in cache_set_flush() then the
kernel crash occurred as below:
[ 846.712887] bcache: register_cache() error drbd6: cannot allocate memory
[ 846.713242] bcache: register_bcache() error : failed to register device
[ 846.713336] bcache: cache_set_free() Cache set 2f84bdc1-498a-4f2f-98a7-01946bf54287 unregistered
[ 846.713768] BUG: unable to handle kernel NULL pointer dereference at 00000000000009f8
[ 846.714790] PGD 0 P4D 0
[ 846.715129] Oops: 0000 [#1] SMP PTI
[ 846.715472] CPU: 19 PID: 5057 Comm: kworker/19:16 Kdump: loaded Tainted: G OE --------- - - 4.18.0-147.5.1.el8_1.5es.3.x86_64 #1
[ 846.716082] Hardware name: ESPAN GI-25212/X11DPL-i, BIOS 2.1 06/15/2018
[ 846.716451] Workqueue: events cache_set_flush [bcache]
[ 846.716808] RIP: 0010:cache_set_flush+0xc9/0x1b0 [bcache]
[ 846.717155] Code: 00 4c 89 a5 b0 03 00 00 48 8b 85 68 f6 ff ff a8 08 0f 84 88 00 00 00 31 db 66 83 bd 3c f7 ff ff 00 48 8b 85 48 ff ff ff 74 28 <48> 8b b8 f8 09 00 00 48 85 ff 74 05 e8 b6 58 a2 e1 0f b7 95 3c f7
[ 846.718026] RSP: 0018:ffffb56dcf85fe70 EFLAGS: 00010202
[ 846.718372] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[ 846.718725] RDX: 0000000000000001 RSI: 0000000040000001 RDI: 0000000000000000
[ 846.719076] RBP: ffffa0ccc0f20df8 R08: ffffa0ce1fedb118 R09: 000073746e657665
[ 846.719428] R10: 8080808080808080 R11: 0000000000000000 R12: ffffa0ce1fee8700
[ 846.719779] R13: ffffa0ccc0f211a8 R14: ffffa0cd1b902840 R15: ffffa0ccc0f20e00
[ 846.720132] FS: 0000000000000000(0000) GS:ffffa0ce1fec0000(0000) knlGS:0000000000000000
[ 846.720726] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 846.721073] CR2: 00000000000009f8 CR3: 00000008ba00a005 CR4: 00000000007606e0
[ 846.721426] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 846.721778] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 846.722131] PKRU: 55555554
[ 846.722467] Call Trace:
[ 846.722814] process_one_work+0x1a7/0x3b0
[ 846.723157] worker_thread+0x30/0x390
[ 846.723501] ? create_worker+0x1a0/0x1a0
[ 846.723844] kthread+0x112/0x130
[ 846.724184] ? kthread_flush_work_fn+0x10/0x10
[ 846.724535] ret_from_fork+0x35/0x40
Now, check whether that ca is NULL in LINE#1655 to fix the issue.
Signed-off-by: Linggang Zeng <linggang.zeng@easystack.cn>
Signed-off-by: Mingzhe Zou <mingzhe.zou@easystack.cn>
Signed-off-by: Coly Li <colyli@kernel.org>
Link: https://lore.kernel.org/r/20250527051601.74407-2-colyli@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit b2e382ae12a63560fca35050498e19e760adf8c0 upstream.
Commit 028ddcac477b ("bcache: Remove unnecessary NULL point check in
node allocations") leads a NULL pointer deference in cache_set_flush().
1721 if (!IS_ERR_OR_NULL(c->root))
1722 list_add(&c->root->list, &c->btree_cache);
>From the above code in cache_set_flush(), if previous registration code
fails before allocating c->root, it is possible c->root is NULL as what
it is initialized. __bch_btree_node_alloc() never returns NULL but
c->root is possible to be NULL at above line 1721.
This patch replaces IS_ERR() by IS_ERR_OR_NULL() to fix this.
Fixes: 028ddcac477b ("bcache: Remove unnecessary NULL point check in node allocations")
Signed-off-by: Liequan Che <cheliequan@inspur.com>
Cc: stable@vger.kernel.org
Cc: Zheng Wang <zyytlz.wz@163.com>
Reviewed-by: Mingzhe Zou <mingzhe.zou@easystack.cn>
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20241202115638.28957-1-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 339b84ab6b1d66900c27bd999271cb2ae40ce812 ]
If a BUG_ON() can be hit in the wild, it shouldn't be a BUG_ON()
For reference, this has popped up once in the CI, and we'll need more
info to debug it:
03240 ------------[ cut here ]------------
03240 kernel BUG at lib/closure.c:21!
03240 kernel BUG at lib/closure.c:21!
03240 Internal error: Oops - BUG: 00000000f2000800 [#1] SMP
03240 Modules linked in:
03240 CPU: 15 PID: 40534 Comm: kworker/u80:1 Not tainted 6.10.0-rc4-ktest-ga56da69799bd #25570
03240 Hardware name: linux,dummy-virt (DT)
03240 Workqueue: btree_update btree_interior_update_work
03240 pstate: 00001005 (nzcv daif -PAN -UAO -TCO -DIT +SSBS BTYPE=--)
03240 pc : closure_put+0x224/0x2a0
03240 lr : closure_put+0x24/0x2a0
03240 sp : ffff0000d12071c0
03240 x29: ffff0000d12071c0 x28: dfff800000000000 x27: ffff0000d1207360
03240 x26: 0000000000000040 x25: 0000000000000040 x24: 0000000000000040
03240 x23: ffff0000c1f20180 x22: 0000000000000000 x21: ffff0000c1f20168
03240 x20: 0000000040000000 x19: ffff0000c1f20140 x18: 0000000000000001
03240 x17: 0000000000003aa0 x16: 0000000000003ad0 x15: 1fffe0001c326974
03240 x14: 0000000000000a1e x13: 0000000000000000 x12: 1fffe000183e402d
03240 x11: ffff6000183e402d x10: dfff800000000000 x9 : ffff6000183e402e
03240 x8 : 0000000000000001 x7 : 00009fffe7c1bfd3 x6 : ffff0000c1f2016b
03240 x5 : ffff0000c1f20168 x4 : ffff6000183e402e x3 : ffff800081391954
03240 x2 : 0000000000000001 x1 : 0000000000000000 x0 : 00000000a8000000
03240 Call trace:
03240 closure_put+0x224/0x2a0
03240 bch2_check_for_deadlock+0x910/0x1028
03240 bch2_six_check_for_deadlock+0x1c/0x30
03240 six_lock_slowpath.isra.0+0x29c/0xed0
03240 six_lock_ip_waiter+0xa8/0xf8
03240 __bch2_btree_node_lock_write+0x14c/0x298
03240 bch2_trans_lock_write+0x6d4/0xb10
03240 __bch2_trans_commit+0x135c/0x5520
03240 btree_interior_update_work+0x1248/0x1c10
03240 process_scheduled_works+0x53c/0xd90
03240 worker_thread+0x370/0x8c8
03240 kthread+0x258/0x2e8
03240 ret_from_fork+0x10/0x20
03240 Code: aa1303e0 d63f0020 a94363f7 17ffff8c (d4210000)
03240 ---[ end trace 0000000000000000 ]---
03240 Kernel panic - not syncing: Oops - BUG: Fatal exception
03240 SMP: stopping secondary CPUs
03241 SMP: failed to stop secondary CPUs 13,15
03241 Kernel Offset: disabled
03241 CPU features: 0x00,00000003,80000008,4240500b
03241 Memory Limit: none
03241 ---[ end Kernel panic - not syncing: Oops - BUG: Fatal exception ]---
03246 ========= FAILED TIMEOUT copygc_torture_no_checksum in 7200s
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
[ Resolve minor conflicts to fix CVE-2024-42252 ]
Signed-off-by: Bin Lan <bin.lan.cn@windriver.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 3a861560ccb35f2a4f0a4b8207fa7c2a35fc7f31 upstream.
btree_iter is used in two ways: either allocated on the stack with a
fixed size MAX_BSETS, or from a mempool with a dynamic size based on the
specific cache set. Previously, the struct had a fixed-length array of
size MAX_BSETS which was indexed out-of-bounds for the dynamically-sized
iterators, which causes UBSAN to complain.
This patch uses the same approach as in bcachefs's sort_iter and splits
the iterator into a btree_iter with a flexible array member and a
btree_iter_stack which embeds a btree_iter as well as a fixed-length
data array.
Cc: stable@vger.kernel.org
Closes: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2039368
Signed-off-by: Matthew Mirvish <matthew@mm12.xyz>
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20240509011117.2697-3-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 3eba5e0b2422aec3c9e79822029599961fdcab97 ]
In run_cache_set() after c->root returned from bch_btree_node_get(), it
is checked by IS_ERR_OR_NULL(). Indeed it is unncessary to check NULL
because bch_btree_node_get() will not return NULL pointer to caller.
This patch replaces IS_ERR_OR_NULL() by IS_ERR() for the above reason.
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20231120052503.6122-11-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 31f5b956a197d4ec25c8a07cb3a2ab69d0c0b82f ]
This patch adds code comments to bch_btree_node_get() and
__bch_btree_node_alloc() that NULL pointer will not be returned and it
is unnecessary to check NULL pointer by the callers of these routines.
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20231120052503.6122-10-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit be93825f0e6428c2d3f03a6e4d447dc48d33d7ff ]
Variable cur_idx is being initialized with a value that is never read,
it is being re-assigned later in a while-loop. Remove the redundant
assignment. Cleans up clang scan build warning:
drivers/md/bcache/writeback.c:916:2: warning: Value stored to 'cur_idx'
is never read [deadcode.DeadStores]
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: Coly Li <colyli@suse.de>
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20231120052503.6122-4-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit baf8fb7e0e5ec54ea0839f0c534f2cdcd79bea9c ]
Arraies bcache->stripe_sectors_dirty and bcache->full_dirty_stripes are
used for dirty data writeback, their sizes are decided by backing device
capacity and stripe size. Larger backing device capacity or smaller
stripe size make these two arraies occupies more dynamic memory space.
Currently bcache->stripe_size is directly inherited from
queue->limits.io_opt of underlying storage device. For normal hard
drives, its limits.io_opt is 0, and bcache sets the corresponding
stripe_size to 1TB (1<<31 sectors), it works fine 10+ years. But for
devices do declare value for queue->limits.io_opt, small stripe_size
(comparing to 1TB) becomes an issue for oversize memory allocations of
bcache->stripe_sectors_dirty and bcache->full_dirty_stripes, while the
capacity of hard drives gets much larger in recent decade.
For example a raid5 array assembled by three 20TB hardrives, the raid
device capacity is 40TB with typical 512KB limits.io_opt. After the math
calculation in bcache code, these two arraies will occupy 400MB dynamic
memory. Even worse Andrea Tomassetti reports that a 4KB limits.io_opt is
declared on a new 2TB hard drive, then these two arraies request 2GB and
512MB dynamic memory from kzalloc(). The result is that bcache device
always fails to initialize on his system.
To avoid the oversize memory allocation, bcache->stripe_size should not
directly inherited by queue->limits.io_opt from the underlying device.
This patch defines BCH_MIN_STRIPE_SZ (4MB) as minimal bcache stripe size
and set bcache device's stripe size against the declared limits.io_opt
value from the underlying storage device,
- If the declared limits.io_opt > BCH_MIN_STRIPE_SZ, bcache device will
set its stripe size directly by this limits.io_opt value.
- If the declared limits.io_opt < BCH_MIN_STRIPE_SZ, bcache device will
set its stripe size by a value multiplying limits.io_opt and euqal or
large than BCH_MIN_STRIPE_SZ.
Then the minimal stripe size of a bcache device will always be >= 4MB.
For a 40TB raid5 device with 512KB limits.io_opt, memory occupied by
bcache->stripe_sectors_dirty and bcache->full_dirty_stripes will be 50MB
in total. For a 2TB hard drive with 4KB limits.io_opt, memory occupied
by these two arraies will be 2.5MB in total.
Such mount of memory allocated for bcache->stripe_sectors_dirty and
bcache->full_dirty_stripes is reasonable for most of storage devices.
Reported-by: Andrea Tomassetti <andrea.tomassetti-opensource@devo.com>
Signed-off-by: Coly Li <colyli@suse.de>
Reviewed-by: Eric Wheeler <bcache@lists.ewheeler.net>
Link: https://lore.kernel.org/r/20231120052503.6122-2-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit bb6cc253861bd5a7cf8439e2118659696df9619f upstream.
Commit 028ddcac477b ("bcache: Remove unnecessary NULL point check in
node allocations") replaced IS_ERR_OR_NULL by IS_ERR. This leads to a
NULL pointer dereference.
BUG: kernel NULL pointer dereference, address: 0000000000000080
Call Trace:
? __die_body.cold+0x1a/0x1f
? page_fault_oops+0xd2/0x2b0
? exc_page_fault+0x70/0x170
? asm_exc_page_fault+0x22/0x30
? btree_node_free+0xf/0x160 [bcache]
? up_write+0x32/0x60
btree_gc_coalesce+0x2aa/0x890 [bcache]
? bch_extent_bad+0x70/0x170 [bcache]
btree_gc_recurse+0x130/0x390 [bcache]
? btree_gc_mark_node+0x72/0x230 [bcache]
bch_btree_gc+0x5da/0x600 [bcache]
? cpuusage_read+0x10/0x10
? bch_btree_gc+0x600/0x600 [bcache]
bch_gc_thread+0x135/0x180 [bcache]
The relevant code starts with:
new_nodes[0] = NULL;
for (i = 0; i < nodes; i++) {
if (__bch_keylist_realloc(&keylist, bkey_u64s(&r[i].b->key)))
goto out_nocoalesce;
// ...
out_nocoalesce:
// ...
for (i = 0; i < nodes; i++)
if (!IS_ERR(new_nodes[i])) { // IS_ERR_OR_NULL before
028ddcac477b
btree_node_free(new_nodes[i]); // new_nodes[0] is NULL
rw_unlock(true, new_nodes[i]);
}
This patch replaces IS_ERR() by IS_ERR_OR_NULL() to fix this.
Fixes: 028ddcac477b ("bcache: Remove unnecessary NULL point check in node allocations")
Link: https://lore.kernel.org/all/3DF4A87A-2AC1-4893-AE5F-E921478419A9@suse.de/
Cc: stable@vger.kernel.org
Cc: Zheng Wang <zyytlz.wz@163.com>
Cc: Coly Li <colyli@suse.de>
Signed-off-by: Markus Weippert <markus@gekmihesg.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit e34820f984512b433ee1fc291417e60c47d56727 upstream.
We had a problem with io hung because it was waiting for c->root to
release the lock.
crash> cache_set.root -l cache_set.list ffffa03fde4c0050
root = 0xffff802ef454c800
crash> btree -o 0xffff802ef454c800 | grep rw_semaphore
[ffff802ef454c858] struct rw_semaphore lock;
crash> struct rw_semaphore ffff802ef454c858
struct rw_semaphore {
count = {
counter = -4294967297
},
wait_list = {
next = 0xffff00006786fc28,
prev = 0xffff00005d0efac8
},
wait_lock = {
raw_lock = {
{
val = {
counter = 0
},
{
locked = 0 '\000',
pending = 0 '\000'
},
{
locked_pending = 0,
tail = 0
}
}
}
},
osq = {
tail = {
counter = 0
}
},
owner = 0xffffa03fdc586603
}
The "counter = -4294967297" means that lock count is -1 and a write lock
is being attempted. Then, we found that there is a btree with a counter
of 1 in btree_cache_freeable.
crash> cache_set -l cache_set.list ffffa03fde4c0050 -o|grep btree_cache
[ffffa03fde4c1140] struct list_head btree_cache;
[ffffa03fde4c1150] struct list_head btree_cache_freeable;
[ffffa03fde4c1160] struct list_head btree_cache_freed;
[ffffa03fde4c1170] unsigned int btree_cache_used;
[ffffa03fde4c1178] wait_queue_head_t btree_cache_wait;
[ffffa03fde4c1190] struct task_struct *btree_cache_alloc_lock;
crash> list -H ffffa03fde4c1140|wc -l
973
crash> list -H ffffa03fde4c1150|wc -l
1123
crash> cache_set.btree_cache_used -l cache_set.list ffffa03fde4c0050
btree_cache_used = 2097
crash> list -s btree -l btree.list -H ffffa03fde4c1140|grep -E -A2 "^ lock = {" > btree_cache.txt
crash> list -s btree -l btree.list -H ffffa03fde4c1150|grep -E -A2 "^ lock = {" > btree_cache_freeable.txt
[root@node-3 127.0.0.1-2023-08-04-16:40:28]# pwd
/var/crash/127.0.0.1-2023-08-04-16:40:28
[root@node-3 127.0.0.1-2023-08-04-16:40:28]# cat btree_cache.txt|grep counter|grep -v "counter = 0"
[root@node-3 127.0.0.1-2023-08-04-16:40:28]# cat btree_cache_freeable.txt|grep counter|grep -v "counter = 0"
counter = 1
We found that this is a bug in bch_sectors_dirty_init() when locking c->root:
(1). Thread X has locked c->root(A) write.
(2). Thread Y failed to lock c->root(A), waiting for the lock(c->root A).
(3). Thread X bch_btree_set_root() changes c->root from A to B.
(4). Thread X releases the lock(c->root A).
(5). Thread Y successfully locks c->root(A).
(6). Thread Y releases the lock(c->root B).
down_write locked ---(1)----------------------┐
| |
| down_read waiting ---(2)----┐ |
| | ┌-------------┐ ┌-------------┐
bch_btree_set_root ===(3)========>> | c->root A | | c->root B |
| | └-------------┘ └-------------┘
up_write ---(4)---------------------┘ | |
| | |
down_read locked ---(5)-----------┘ |
| |
up_read ---(6)-----------------------------┘
Since c->root may change, the correct steps to lock c->root should be
the same as bch_root_usage(), compare after locking.
static unsigned int bch_root_usage(struct cache_set *c)
{
unsigned int bytes = 0;
struct bkey *k;
struct btree *b;
struct btree_iter iter;
goto lock_root;
do {
rw_unlock(false, b);
lock_root:
b = c->root;
rw_lock(false, b, b->level);
} while (b != c->root);
for_each_key_filter(&b->keys, k, &iter, bch_ptr_bad)
bytes += bkey_bytes(k);
rw_unlock(false, b);
return (bytes * 100) / btree_bytes(c);
}
Fixes: b144e45fc576 ("bcache: make bch_sectors_dirty_init() to be multithreaded")
Signed-off-by: Mingzhe Zou <mingzhe.zou@easystack.cn>
Cc: <stable@vger.kernel.org>
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20231120052503.6122-7-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 7cc47e64d3d69786a2711a4767e26b26ba63d7ed upstream.
We found that after long run, the dirty_data of the bcache device
will have errors. This error cannot be eliminated unless re-register.
We also found that reattach after detach, this error can accumulate.
In bch_sectors_dirty_init(), all inode <= d->id keys will be recounted
again. This is wrong, we only need to count the keys of the current
device.
Fixes: b144e45fc576 ("bcache: make bch_sectors_dirty_init() to be multithreaded")
Signed-off-by: Mingzhe Zou <mingzhe.zou@easystack.cn>
Cc: <stable@vger.kernel.org>
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20231120052503.6122-6-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 2c7f497ac274a14330208b18f6f734000868ebf9 upstream.
In SHOW(), the variable 'n' is of type 'size_t.' While there is a
conditional check to verify that 'n' is not equal to zero before
executing the 'do_div' macro, concerns arise regarding potential
division by zero error in 64-bit environments.
The concern arises when 'n' is 64 bits in size, greater than zero, and
the lower 32 bits of it are zeros. In such cases, the conditional check
passes because 'n' is non-zero, but the 'do_div' macro casts 'n' to
'uint32_t,' effectively truncating it to its lower 32 bits.
Consequently, the 'n' value becomes zero.
To fix this potential division by zero error and ensure precise
division handling, this commit replaces the 'do_div' macro with
div64_u64(). div64_u64() is designed to work with 64-bit operands,
guaranteeing that division is performed correctly.
This change enhances the robustness of the code, ensuring that division
operations yield accurate results in all scenarios, eliminating the
possibility of division by zero, and improving compatibility across
different 64-bit environments.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Signed-off-by: Rand Deeb <rand.sec96@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20231120052503.6122-5-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 777967e7e9f6f5f3e153abffb562bffaf4430d26 upstream.
In btree_gc_rewrite_node(), pointer 'n' is not checked after it returns
from btree_gc_rewrite_node(). There is potential possibility that 'n' is
a non NULL ERR_PTR(), referencing such error code is not permitted in
following code. Therefore a return value checking is necessary after 'n'
is back from btree_node_alloc_replacement().
Signed-off-by: Coly Li <colyli@suse.de>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20231120052503.6122-3-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 2faac25d7958c4761bb8cec54adb79f806783ad6 upstream.
We get a kernel crash about "unable to handle kernel paging request":
```dmesg
[368033.032005] BUG: unable to handle kernel paging request at ffffffffad9ae4b5
[368033.032007] PGD fc3a0d067 P4D fc3a0d067 PUD fc3a0e063 PMD 8000000fc38000e1
[368033.032012] Oops: 0003 [#1] SMP PTI
[368033.032015] CPU: 23 PID: 55090 Comm: bch_dirtcnt[0] Kdump: loaded Tainted: G OE --------- - - 4.18.0-147.5.1.es8_24.x86_64 #1
[368033.032017] Hardware name: Tsinghua Tongfang THTF Chaoqiang Server/072T6D, BIOS 2.4.3 01/17/2017
[368033.032027] RIP: 0010:native_queued_spin_lock_slowpath+0x183/0x1d0
[368033.032029] Code: 8b 02 48 85 c0 74 f6 48 89 c1 eb d0 c1 e9 12 83 e0
03 83 e9 01 48 c1 e0 05 48 63 c9 48 05 c0 3d 02 00 48 03 04 cd 60 68 93
ad <48> 89 10 8b 42 08 85 c0 75 09 f3 90 8b 42 08 85 c0 74 f7 48 8b 02
[368033.032031] RSP: 0018:ffffbb48852abe00 EFLAGS: 00010082
[368033.032032] RAX: ffffffffad9ae4b5 RBX: 0000000000000246 RCX: 0000000000003bf3
[368033.032033] RDX: ffff97b0ff8e3dc0 RSI: 0000000000600000 RDI: ffffbb4884743c68
[368033.032034] RBP: 0000000000000001 R08: 0000000000000000 R09: 000007ffffffffff
[368033.032035] R10: ffffbb486bb01000 R11: 0000000000000001 R12: ffffffffc068da70
[368033.032036] R13: 0000000000000003 R14: 0000000000000000 R15: 0000000000000000
[368033.032038] FS: 0000000000000000(0000) GS:ffff97b0ff8c0000(0000) knlGS:0000000000000000
[368033.032039] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[368033.032040] CR2: ffffffffad9ae4b5 CR3: 0000000fc3a0a002 CR4: 00000000003626e0
[368033.032042] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[368033.032043] bcache: bch_cached_dev_attach() Caching rbd479 as bcache462 on set 8cff3c36-4a76-4242-afaa-7630206bc70b
[368033.032045] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[368033.032046] Call Trace:
[368033.032054] _raw_spin_lock_irqsave+0x32/0x40
[368033.032061] __wake_up_common_lock+0x63/0xc0
[368033.032073] ? bch_ptr_invalid+0x10/0x10 [bcache]
[368033.033502] bch_dirty_init_thread+0x14c/0x160 [bcache]
[368033.033511] ? read_dirty_submit+0x60/0x60 [bcache]
[368033.033516] kthread+0x112/0x130
[368033.033520] ? kthread_flush_work_fn+0x10/0x10
[368033.034505] ret_from_fork+0x35/0x40
```
The crash occurred when call wake_up(&state->wait), and then we want
to look at the value in the state. However, bch_sectors_dirty_init()
is not found in the stack of any task. Since state is allocated on
the stack, we guess that bch_sectors_dirty_init() has exited, causing
bch_dirty_init_thread() to be unable to handle kernel paging request.
In order to verify this idea, we added some printing information during
wake_up(&state->wait). We find that "wake up" is printed twice, however
we only expect the last thread to wake up once.
```dmesg
[ 994.641004] alcache: bch_dirty_init_thread() wake up
[ 994.641018] alcache: bch_dirty_init_thread() wake up
[ 994.641523] alcache: bch_sectors_dirty_init() init exit
```
There is a race. If bch_sectors_dirty_init() exits after the first wake
up, the second wake up will trigger this bug("unable to handle kernel
paging request").
Proceed as follows:
bch_sectors_dirty_init
kthread_run ==============> bch_dirty_init_thread(bch_dirtcnt[0])
... ...
atomic_inc(&state.started) ...
... ...
atomic_read(&state.enough) ...
... atomic_set(&state->enough, 1)
kthread_run ======================================================> bch_dirty_init_thread(bch_dirtcnt[1])
... atomic_dec_and_test(&state->started) ...
atomic_inc(&state.started) ... ...
... wake_up(&state->wait) ...
atomic_read(&state.enough) atomic_dec_and_test(&state->started)
... ...
wait_event(state.wait, atomic_read(&state.started) == 0) ...
return ...
wake_up(&state->wait)
We believe it is very common to wake up twice if there is no dirty, but
crash is an extremely low probability event. It's hard for us to reproduce
this issue. We attached and detached continuously for a week, with a total
of more than one million attaches and only one crash.
Putting atomic_inc(&state.started) before kthread_run() can avoid waking
up twice.
Fixes: b144e45fc576 ("bcache: make bch_sectors_dirty_init() to be multithreaded")
Signed-off-by: Mingzhe Zou <mingzhe.zou@easystack.cn>
Cc: <stable@vger.kernel.org>
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20231120052503.6122-8-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit f72f4312d4388376fc8a1f6cf37cb21a0d41758b upstream.
Commit 028ddcac477b ("bcache: Remove unnecessary NULL point check in
node allocations") do the following change inside btree_gc_coalesce(),
31 @@ -1340,7 +1340,7 @@ static int btree_gc_coalesce(
32 memset(new_nodes, 0, sizeof(new_nodes));
33 closure_init_stack(&cl);
34
35 - while (nodes < GC_MERGE_NODES && !IS_ERR_OR_NULL(r[nodes].b))
36 + while (nodes < GC_MERGE_NODES && !IS_ERR(r[nodes].b))
37 keys += r[nodes++].keys;
38
39 blocks = btree_default_blocks(b->c) * 2 / 3;
At line 35 the original r[nodes].b is not always allocatored from
__bch_btree_node_alloc(), and possibly initialized as NULL pointer by
caller of btree_gc_coalesce(). Therefore the change at line 36 is not
correct.
This patch replaces the mistaken IS_ERR() by IS_ERR_OR_NULL() to avoid
potential issue.
Fixes: 028ddcac477b ("bcache: Remove unnecessary NULL point check in node allocations")
Cc: <stable@vger.kernel.org> # 6.5+
Cc: Zheng Wang <zyytlz.wz@163.com>
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20231120052503.6122-9-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 80fca8a10b604afad6c14213fdfd816c4eda3ee4 upstream.
In some specific situations, the return value of __bch_btree_node_alloc
may be NULL. This may lead to a potential NULL pointer dereference in
caller function like a calling chain :
btree_split->bch_btree_node_alloc->__bch_btree_node_alloc.
Fix it by initializing the return value in __bch_btree_node_alloc.
Fixes: cafe56359144 ("bcache: A block layer cache")
Cc: stable@vger.kernel.org
Signed-off-by: Zheng Wang <zyytlz.wz@163.com>
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20230615121223.22502-6-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 028ddcac477b691dd9205c92f991cc15259d033e upstream.
Due to the previous fix of __bch_btree_node_alloc, the return value will
never be a NULL pointer. So IS_ERR is enough to handle the failure
situation. Fix it by replacing IS_ERR_OR_NULL check by an IS_ERR check.
Fixes: cafe56359144 ("bcache: A block layer cache")
Cc: stable@vger.kernel.org
Signed-off-by: Zheng Wang <zyytlz.wz@163.com>
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20230615121223.22502-5-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit f0854489fc07d2456f7cc71a63f4faf9c716ffbe upstream.
We get a kernel crash about "list_add corruption. next->prev should be
prev (ffff9c801bc01210), but was ffff9c77b688237c.
(next=ffffae586d8afe68)."
crash> struct list_head 0xffff9c801bc01210
struct list_head {
next = 0xffffae586d8afe68,
prev = 0xffffae586d8afe68
}
crash> struct list_head 0xffff9c77b688237c
struct list_head {
next = 0x0,
prev = 0x0
}
crash> struct list_head 0xffffae586d8afe68
struct list_head struct: invalid kernel virtual address: ffffae586d8afe68 type: "gdb_readmem_callback"
Cannot access memory at address 0xffffae586d8afe68
[230469.019492] Call Trace:
[230469.032041] prepare_to_wait+0x8a/0xb0
[230469.044363] ? bch_btree_keys_free+0x6c/0xc0 [escache]
[230469.056533] mca_cannibalize_lock+0x72/0x90 [escache]
[230469.068788] mca_alloc+0x2ae/0x450 [escache]
[230469.080790] bch_btree_node_get+0x136/0x2d0 [escache]
[230469.092681] bch_btree_check_thread+0x1e1/0x260 [escache]
[230469.104382] ? finish_wait+0x80/0x80
[230469.115884] ? bch_btree_check_recurse+0x1a0/0x1a0 [escache]
[230469.127259] kthread+0x112/0x130
[230469.138448] ? kthread_flush_work_fn+0x10/0x10
[230469.149477] ret_from_fork+0x35/0x40
bch_btree_check_thread() and bch_dirty_init_thread() may call
mca_cannibalize() to cannibalize other cached btree nodes. Only one thread
can do it at a time, so the op of other threads will be added to the
btree_cache_wait list.
We must call finish_wait() to remove op from btree_cache_wait before free
it's memory address. Otherwise, the list will be damaged. Also should call
bch_cannibalize_unlock() to release the btree_cache_alloc_lock and wake_up
other waiters.
Fixes: 8e7102273f59 ("bcache: make bch_btree_check() to be multithreaded")
Fixes: b144e45fc576 ("bcache: make bch_sectors_dirty_init() to be multithreaded")
Cc: stable@vger.kernel.org
Signed-off-by: Mingzhe Zou <mingzhe.zou@easystack.cn>
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20230615121223.22502-7-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
[ Upstream commit be0d8f48ad97f5b775b0af3310343f676dbf318a ]
struct bkey has internal padding in a union, but it isn't always named
the same (e.g. key ## _pad, key_p, etc). This makes it extremely hard
for the compiler to reason about the available size of copies done
against such keys. Use unsafe_memcpy() for now, to silence the many
run-time false positive warnings:
memcpy: detected field-spanning write (size 264) of single field "&i->j" at drivers/md/bcache/journal.c:152 (size 240)
memcpy: detected field-spanning write (size 24) of single field "&b->key" at drivers/md/bcache/btree.c:939 (size 16)
memcpy: detected field-spanning write (size 24) of single field "&temp.key" at drivers/md/bcache/extents.c:428 (size 16)
Reported-by: Alexandre Pereira <alexpereira@disroot.org>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216785
Acked-by: Coly Li <colyli@suse.de>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: linux-bcache@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230106060229.never.047-kees@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
Rather than incurring a division or requesting too many random bytes for
the given range, use the prandom_u32_max() function, which only takes
the minimum required bytes from the RNG and avoids divisions. This was
done mechanically with this coccinelle script:
@basic@
expression E;
type T;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
typedef u64;
@@
(
- ((T)get_random_u32() % (E))
+ prandom_u32_max(E)
|
- ((T)get_random_u32() & ((E) - 1))
+ prandom_u32_max(E * XXX_MAKE_SURE_E_IS_POW2)
|
- ((u64)(E) * get_random_u32() >> 32)
+ prandom_u32_max(E)
|
- ((T)get_random_u32() & ~PAGE_MASK)
+ prandom_u32_max(PAGE_SIZE)
)
@multi_line@
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
identifier RAND;
expression E;
@@
- RAND = get_random_u32();
... when != RAND
- RAND %= (E);
+ RAND = prandom_u32_max(E);
// Find a potential literal
@literal_mask@
expression LITERAL;
type T;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
position p;
@@
((T)get_random_u32()@p & (LITERAL))
// Add one to the literal.
@script:python add_one@
literal << literal_mask.LITERAL;
RESULT;
@@
value = None
if literal.startswith('0x'):
value = int(literal, 16)
elif literal[0] in '123456789':
value = int(literal, 10)
if value is None:
print("I don't know how to handle %s" % (literal))
cocci.include_match(False)
elif value == 2**32 - 1 or value == 2**31 - 1 or value == 2**24 - 1 or value == 2**16 - 1 or value == 2**8 - 1:
print("Skipping 0x%x for cleanup elsewhere" % (value))
cocci.include_match(False)
elif value & (value + 1) != 0:
print("Skipping 0x%x because it's not a power of two minus one" % (value))
cocci.include_match(False)
elif literal.startswith('0x'):
coccinelle.RESULT = cocci.make_expr("0x%x" % (value + 1))
else:
coccinelle.RESULT = cocci.make_expr("%d" % (value + 1))
// Replace the literal mask with the calculated result.
@plus_one@
expression literal_mask.LITERAL;
position literal_mask.p;
expression add_one.RESULT;
identifier FUNC;
@@
- (FUNC()@p & (LITERAL))
+ prandom_u32_max(RESULT)
@collapse_ret@
type T;
identifier VAR;
expression E;
@@
{
- T VAR;
- VAR = (E);
- return VAR;
+ return E;
}
@drop_var@
type T;
identifier VAR;
@@
{
- T VAR;
... when != VAR
}
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: KP Singh <kpsingh@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz> # for ext4 and sbitmap
Reviewed-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> # for drbd
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
|
|
Inside set_at_max_writeback_rate() the calculation in following if()
check is wrong,
if (atomic_inc_return(&c->idle_counter) <
atomic_read(&c->attached_dev_nr) * 6)
Because each attached backing device has its own writeback thread
running and increasing c->idle_counter, the counter increates much
faster than expected. The correct calculation should be,
(counter / dev_nr) < dev_nr * 6
which equals to,
counter < dev_nr * dev_nr * 6
This patch fixes the above mistake with correct calculation, and helper
routine idle_counter_exceeded() is added to make code be more clear.
Reported-by: Mingzhe Zou <mingzhe.zou@easystack.cn>
Signed-off-by: Coly Li <colyli@suse.de>
Acked-by: Mingzhe Zou <mingzhe.zou@easystack.cn>
Link: https://lore.kernel.org/r/20220919161647.81238-6-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Delete the redundant word 'we'.
Signed-off-by: Jilin Yuan <yuanjilin@cdjrlc.com>
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20220919161647.81238-5-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Remove the redundant word `by`, correct the typo `creaated`.
CC: Kent Overstreet <kent.overstreet@gmail.com>
CC: linux-bcache@vger.kernel.org
Signed-off-by: Jules Maselbas <jmaselbas@kalray.eu>
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20220919161647.81238-4-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
This is a cleanup for commit 1616a4c2ab1a ("bcache: remove bcache device
self-defined readahead")', currently no user for
bch_mark_cache_readahead() since that commit.
Signed-off-by: Lin Feng <linf@wangsu.com>
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20220919161647.81238-3-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
All pending works will be drained by destroy_workqueue(), no need to call
flush_workqueue() explicitly.
Signed-off-by: Li Lei <lilei@szsandstone.com>
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20220919161647.81238-2-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
"Most of the MM queue. A few things are still pending.
Liam's maple tree rework didn't make it. This has resulted in a few
other minor patch series being held over for next time.
Multi-gen LRU still isn't merged as we were waiting for mapletree to
stabilize. The current plan is to merge MGLRU into -mm soon and to
later reintroduce mapletree, with a view to hopefully getting both
into 6.1-rc1.
Summary:
- The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe
Lin, Yang Shi, Anshuman Khandual and Mike Rapoport
- Some kmemleak fixes from Patrick Wang and Waiman Long
- DAMON updates from SeongJae Park
- memcg debug/visibility work from Roman Gushchin
- vmalloc speedup from Uladzislau Rezki
- more folio conversion work from Matthew Wilcox
- enhancements for coherent device memory mapping from Alex Sierra
- addition of shared pages tracking and CoW support for fsdax, from
Shiyang Ruan
- hugetlb optimizations from Mike Kravetz
- Mel Gorman has contributed some pagealloc changes to improve
latency and realtime behaviour.
- mprotect soft-dirty checking has been improved by Peter Xu
- Many other singleton patches all over the place"
[ XFS merge from hell as per Darrick Wong in
https://lore.kernel.org/all/YshKnxb4VwXycPO8@magnolia/ ]
* tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (282 commits)
tools/testing/selftests/vm/hmm-tests.c: fix build
mm: Kconfig: fix typo
mm: memory-failure: convert to pr_fmt()
mm: use is_zone_movable_page() helper
hugetlbfs: fix inaccurate comment in hugetlbfs_statfs()
hugetlbfs: cleanup some comments in inode.c
hugetlbfs: remove unneeded header file
hugetlbfs: remove unneeded hugetlbfs_ops forward declaration
hugetlbfs: use helper macro SZ_1{K,M}
mm: cleanup is_highmem()
mm/hmm: add a test for cross device private faults
selftests: add soft-dirty into run_vmtests.sh
selftests: soft-dirty: add test for mprotect
mm/mprotect: fix soft-dirty check in can_change_pte_writable()
mm: memcontrol: fix potential oom_lock recursion deadlock
mm/gup.c: fix formatting in check_and_migrate_movable_page()
xfs: fail dax mount if reflink is enabled on a partition
mm/memcontrol.c: remove the redundant updating of stats_flush_threshold
userfaultfd: don't fail on unrecognized features
hugetlb_cgroup: fix wrong hugetlb cgroup numa stat
...
|
|
registration'
The "Asynchronous device registration (EXPERIMENTAL)" Kconfig option is
for 2+ years, it is used when registration takes too much time for
massive amount of cached data, to avoid udev task timeout during boot
time.
Many users and products enable this Kconfig option for quite long time
(e.g. SUSE Linux) and it works as expected and no issue reported.
It is time to remove the "EXPERIMENTAL" tag from this Kconfig item.
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20220719042724.8498-2-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Improve uniformity in the kernel of handling of request operation and
flags by passing these as a single argument.
Cc: Coly Li <colyli@suse.de>
Cc: Mingzhe Zou <mingzhe.zou@easystack.cn>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220714180729.1065367-34-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Improve uniformity in the kernel of handling of request operation and
flags by passing these as a single argument.
Cc: Coly Li <colyli@suse.de>
Cc: Mingzhe Zou <mingzhe.zou@easystack.cn>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220714180729.1065367-33-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Currently shrinkers are anonymous objects. For debugging purposes they
can be identified by count/scan function names, but it's not always
useful: e.g. for superblock's shrinkers it's nice to have at least an
idea of to which superblock the shrinker belongs.
This commit adds names to shrinkers. register_shrinker() and
prealloc_shrinker() functions are extended to take a format and arguments
to master a name.
In some cases it's not possible to determine a good name at the time when
a shrinker is allocated. For such cases shrinker_debugfs_rename() is
provided.
The expected format is:
<subsystem>-<shrinker_type>[:<instance>]-<id>
For some shrinkers an instance can be encoded as (MAJOR:MINOR) pair.
After this change the shrinker debugfs directory looks like:
$ cd /sys/kernel/debug/shrinker/
$ ls
dquota-cache-16 sb-devpts-28 sb-proc-47 sb-tmpfs-42
mm-shadow-18 sb-devtmpfs-5 sb-proc-48 sb-tmpfs-43
mm-zspool:zram0-34 sb-hugetlbfs-17 sb-pstore-31 sb-tmpfs-44
rcu-kfree-0 sb-hugetlbfs-33 sb-rootfs-2 sb-tmpfs-49
sb-aio-20 sb-iomem-12 sb-securityfs-6 sb-tracefs-13
sb-anon_inodefs-15 sb-mqueue-21 sb-selinuxfs-22 sb-xfs:vda1-36
sb-bdev-3 sb-nsfs-4 sb-sockfs-8 sb-zsmalloc-19
sb-bpf-32 sb-pipefs-14 sb-sysfs-26 thp-deferred_split-10
sb-btrfs:vda2-24 sb-proc-25 sb-tmpfs-1 thp-zero-9
sb-cgroup2-30 sb-proc-39 sb-tmpfs-27 xfs-buf:vda1-37
sb-configfs-23 sb-proc-41 sb-tmpfs-29 xfs-inodegc:vda1-38
sb-dax-11 sb-proc-45 sb-tmpfs-35
sb-debugfs-7 sb-proc-46 sb-tmpfs-40
[roman.gushchin@linux.dev: fix build warnings]
Link: https://lkml.kernel.org/r/Yr+ZTnLb9lJk6fJO@castle
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lkml.kernel.org/r/20220601032227.4076670-4-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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blk_cleanup_disk is nothing but a trivial wrapper for put_disk now,
so remove it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20220619060552.1850436-7-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Pull more block driver updates from Jens Axboe:
"A collection of stragglers that were late on sending in their changes
and just followup fixes.
- NVMe fixes pull request via Christoph:
- set controller enable bit in a separate write (Niklas Cassel)
- disable namespace identifiers for the MAXIO MAP1001 (Christoph)
- fix a comment typo (Julia Lawall)"
- MD fixes pull request via Song:
- Remove uses of bdevname (Christoph Hellwig)
- Bug fixes (Guoqing Jiang, and Xiao Ni)
- bcache fixes series (Coly)
- null_blk zoned write fix (Damien)
- nbd fixes (Yu, Zhang)
- Fix for loop partition scanning (Christoph)"
* tag 'for-5.19/drivers-2022-06-02' of git://git.kernel.dk/linux-block: (23 commits)
block: null_blk: Fix null_zone_write()
nvmet: fix typo in comment
nvme: set controller enable bit in a separate write
nvme-pci: disable namespace identifiers for the MAXIO MAP1001
bcache: avoid unnecessary soft lockup in kworker update_writeback_rate()
nbd: use pr_err to output error message
nbd: fix possible overflow on 'first_minor' in nbd_dev_add()
nbd: fix io hung while disconnecting device
nbd: don't clear 'NBD_CMD_INFLIGHT' flag if request is not completed
nbd: fix race between nbd_alloc_config() and module removal
nbd: call genl_unregister_family() first in nbd_cleanup()
md: bcache: check the return value of kzalloc() in detached_dev_do_request()
bcache: memset on stack variables in bch_btree_check() and bch_sectors_dirty_init()
block, loop: support partitions without scanning
bcache: avoid journal no-space deadlock by reserving 1 journal bucket
bcache: remove incremental dirty sector counting for bch_sectors_dirty_init()
bcache: improve multithreaded bch_sectors_dirty_init()
bcache: improve multithreaded bch_btree_check()
md: fix double free of io_acct_set bioset
md: Don't set mddev private to NULL in raid0 pers->free
...
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The kworker routine update_writeback_rate() is schedued to update the
writeback rate in every 5 seconds by default. Before calling
__update_writeback_rate() to do real job, semaphore dc->writeback_lock
should be held by the kworker routine.
At the same time, bcache writeback thread routine bch_writeback_thread()
also needs to hold dc->writeback_lock before flushing dirty data back
into the backing device. If the dirty data set is large, it might be
very long time for bch_writeback_thread() to scan all dirty buckets and
releases dc->writeback_lock. In such case update_writeback_rate() can be
starved for long enough time so that kernel reports a soft lockup warn-
ing started like:
watchdog: BUG: soft lockup - CPU#246 stuck for 23s! [kworker/246:31:179713]
Such soft lockup condition is unnecessary, because after the writeback
thread finishes its job and releases dc->writeback_lock, the kworker
update_writeback_rate() may continue to work and everything is fine
indeed.
This patch avoids the unnecessary soft lockup by the following method,
- Add new member to struct cached_dev
- dc->rate_update_retry (0 by default)
- In update_writeback_rate() call down_read_trylock(&dc->writeback_lock)
firstly, if it fails then lock contention happens.
- If dc->rate_update_retry <= BCH_WBRATE_UPDATE_MAX_SKIPS (15), doesn't
acquire the lock and reschedules the kworker for next try.
- If dc->rate_update_retry > BCH_WBRATE_UPDATE_MAX_SKIPS, no retry
anymore and call down_read(&dc->writeback_lock) to wait for the lock.
By the above method, at worst case update_writeback_rate() may retry for
1+ minutes before blocking on dc->writeback_lock by calling down_read().
For a 4TB cache device with 1TB dirty data, 90%+ of the unnecessary soft
lockup warning message can be avoided.
When retrying to acquire dc->writeback_lock in update_writeback_rate(),
of course the writeback rate cannot be updated. It is fair, because when
the kworker is blocked on the lock contention of dc->writeback_lock, the
writeback rate cannot be updated neither.
This change follows Jens Axboe's suggestion to a more clear and simple
version.
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20220528124550.32834-2-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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The function kzalloc() in detached_dev_do_request() can fail, so its
return value should be checked.
Fixes: bc082a55d25c ("bcache: fix inaccurate io state for detached bcache devices")
Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20220527152818.27545-4-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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bch_sectors_dirty_init()
The local variables check_state (in bch_btree_check()) and state (in
bch_sectors_dirty_init()) should be fully filled by 0, because before
allocating them on stack, they were dynamically allocated by kzalloc().
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20220527152818.27545-2-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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The journal no-space deadlock was reported time to time. Such deadlock
can happen in the following situation.
When all journal buckets are fully filled by active jset with heavy
write I/O load, the cache set registration (after a reboot) will load
all active jsets and inserting them into the btree again (which is
called journal replay). If a journaled bkey is inserted into a btree
node and results btree node split, new journal request might be
triggered. For example, the btree grows one more level after the node
split, then the root node record in cache device super block will be
upgrade by bch_journal_meta() from bch_btree_set_root(). But there is no
space in journal buckets, the journal replay has to wait for new journal
bucket to be reclaimed after at least one journal bucket replayed. This
is one example that how the journal no-space deadlock happens.
The solution to avoid the deadlock is to reserve 1 journal bucket in
run time, and only permit the reserved journal bucket to be used during
cache set registration procedure for things like journal replay. Then
the journal space will never be fully filled, there is no chance for
journal no-space deadlock to happen anymore.
This patch adds a new member "bool do_reserve" in struct journal, it is
inititalized to 0 (false) when struct journal is allocated, and set to
1 (true) by bch_journal_space_reserve() when all initialization done in
run_cache_set(). In the run time when journal_reclaim() tries to
allocate a new journal bucket, free_journal_buckets() is called to check
whether there are enough free journal buckets to use. If there is only
1 free journal bucket and journal->do_reserve is 1 (true), the last
bucket is reserved and free_journal_buckets() will return 0 to indicate
no free journal bucket. Then journal_reclaim() will give up, and try
next time to see whetheer there is free journal bucket to allocate. By
this method, there is always 1 jouranl bucket reserved in run time.
During the cache set registration, journal->do_reserve is 0 (false), so
the reserved journal bucket can be used to avoid the no-space deadlock.
Reported-by: Nikhil Kshirsagar <nkshirsagar@gmail.com>
Signed-off-by: Coly Li <colyli@suse.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220524102336.10684-5-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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After making bch_sectors_dirty_init() being multithreaded, the existing
incremental dirty sector counting in bch_root_node_dirty_init() doesn't
release btree occupation after iterating 500000 (INIT_KEYS_EACH_TIME)
bkeys. Because a read lock is added on btree root node to prevent the
btree to be split during the dirty sectors counting, other I/O requester
has no chance to gain the write lock even restart bcache_btree().
That is to say, the incremental dirty sectors counting is incompatible
to the multhreaded bch_sectors_dirty_init(). We have to choose one and
drop another one.
In my testing, with 512 bytes random writes, I generate 1.2T dirty data
and a btree with 400K nodes. With single thread and incremental dirty
sectors counting, it takes 30+ minites to register the backing device.
And with multithreaded dirty sectors counting, the backing device
registration can be accomplished within 2 minutes.
The 30+ minutes V.S. 2- minutes difference makes me decide to keep
multithreaded bch_sectors_dirty_init() and drop the incremental dirty
sectors counting. This is what this patch does.
But INIT_KEYS_EACH_TIME is kept, in sectors_dirty_init_fn() the CPU
will be released by cond_resched() after every INIT_KEYS_EACH_TIME keys
iterated. This is to avoid the watchdog reports a bogus soft lockup
warning.
Fixes: b144e45fc576 ("bcache: make bch_sectors_dirty_init() to be multithreaded")
Signed-off-by: Coly Li <colyli@suse.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220524102336.10684-4-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
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Commit b144e45fc576 ("bcache: make bch_sectors_dirty_init() to be
multithreaded") makes bch_sectors_dirty_init() to be much faster
when counting dirty sectors by iterating all dirty keys in the btree.
But it isn't in ideal shape yet, still can be improved.
This patch does the following changes to improve current parallel dirty
keys iteration on the btree,
- Add read lock to root node when multiple threads iterating the btree,
to prevent the root node gets split by I/Os from other registered
bcache devices.
- Remove local variable "char name[32]" and generate kernel thread name
string directly when calling kthread_run().
- Allocate "struct bch_dirty_init_state state" directly on stack and
avoid the unnecessary dynamic memory allocation for it.
- Decrease BCH_DIRTY_INIT_THRD_MAX from 64 to 12 which is enough indeed.
- Increase &state->started to count created kernel thread after it
succeeds to create.
- When wait for all dirty key counting threads to finish, use
wait_event() to replace wait_event_interruptible().
With the above changes, the code is more clear, and some potential error
conditions are avoided.
Fixes: b144e45fc576 ("bcache: make bch_sectors_dirty_init() to be multithreaded")
Signed-off-by: Coly Li <colyli@suse.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220524102336.10684-3-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
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Commit 8e7102273f59 ("bcache: make bch_btree_check() to be
multithreaded") makes bch_btree_check() to be much faster when checking
all btree nodes during cache device registration. But it isn't in ideal
shap yet, still can be improved.
This patch does the following thing to improve current parallel btree
nodes check by multiple threads in bch_btree_check(),
- Add read lock to root node while checking all the btree nodes with
multiple threads. Although currently it is not mandatory but it is
good to have a read lock in code logic.
- Remove local variable 'char name[32]', and generate kernel thread name
string directly when calling kthread_run().
- Allocate local variable "struct btree_check_state check_state" on the
stack and avoid unnecessary dynamic memory allocation for it.
- Reduce BCH_BTR_CHKTHREAD_MAX from 64 to 12 which is enough indeed.
- Increase check_state->started to count created kernel thread after it
succeeds to create.
- When wait for all checking kernel threads to finish, use wait_event()
to replace wait_event_interruptible().
With this change, the code is more clear, and some potential error
conditions are avoided.
Fixes: 8e7102273f59 ("bcache: make bch_btree_check() to be multithreaded")
Signed-off-by: Coly Li <colyli@suse.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220524102336.10684-2-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Pull block updates from Jens Axboe:
"Here are the core block changes for 5.19. This contains:
- blk-throttle accounting fix (Laibin)
- Series removing redundant assignments (Michal)
- Expose bio cache via the bio_set, so that DM can use it (Mike)
- Finish off the bio allocation interface cleanups by dealing with
the weirdest member of the family. bio_kmalloc combines a kmalloc
for the bio and bio_vecs with a hidden bio_init call and magic
cleanup semantics (Christoph)
- Clean up the block layer API so that APIs consumed by file systems
are (almost) only struct block_device based, so that file systems
don't have to poke into block layer internals like the
request_queue (Christoph)
- Clean up the blk_execute_rq* API (Christoph)
- Clean up various lose end in the blk-cgroup code to make it easier
to follow in preparation of reworking the blkcg assignment for bios
(Christoph)
- Fix use-after-free issues in BFQ when processes with merged queues
get moved to different cgroups (Jan)
- BFQ fixes (Jan)
- Various fixes and cleanups (Bart, Chengming, Fanjun, Julia, Ming,
Wolfgang, me)"
* tag 'for-5.19/block-2022-05-22' of git://git.kernel.dk/linux-block: (83 commits)
blk-mq: fix typo in comment
bfq: Remove bfq_requeue_request_body()
bfq: Remove superfluous conversion from RQ_BIC()
bfq: Allow current waker to defend against a tentative one
bfq: Relax waker detection for shared queues
blk-cgroup: delete rcu_read_lock_held() WARN_ON_ONCE()
blk-throttle: Set BIO_THROTTLED when bio has been throttled
blk-cgroup: Remove unnecessary rcu_read_lock/unlock()
blk-cgroup: always terminate io.stat lines
block, bfq: make bfq_has_work() more accurate
block, bfq: protect 'bfqd->queued' by 'bfqd->lock'
block: cleanup the VM accounting in submit_bio
block: Fix the bio.bi_opf comment
block: reorder the REQ_ flags
blk-iocost: combine local_stat and desc_stat to stat
block: improve the error message from bio_check_eod
block: allow passing a NULL bdev to bio_alloc_clone/bio_init_clone
block: remove superfluous calls to blkcg_bio_issue_init
kthread: unexport kthread_blkcg
blk-cgroup: cleanup blkcg_maybe_throttle_current
...
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Commit abfc426d1b2f ("block: pass a block_device to bio_clone_fast")
calls the modified bio_alloc_clone() in bcache code as:
bio_init_clone(bio->bi_bdev, bio, orig_bio, GFP_NOIO);
But the first parameter is wrong, where bio->bi_bdev should be
orig_bio->bi_bdev. The wrong bi_bdev panics the kernel when submitting
cache bio.
This patch fixes the wrong bdev parameter usage and avoid the panic.
Fixes: abfc426d1b2f ("block: pass a block_device to bio_clone_fast")
Signed-off-by: Coly Li <colyli@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Mike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220419160425.4148-3-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
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Commit a7c50c940477 ("block: pass a block_device and opf to bio_reset")
moves bch_bio_map() inside journal_write_unlocked() next to the location
where the modified bio_reset() was called.
This change is wrong because calling bch_bio_map() immediately after
bio_reset(), a BUG_ON(!bio->bi_iter.bi_size) inside bch_bio_map() will
be triggered and panic the kernel.
This patch puts bch_bio_map() back to its original correct location in
journal_write_unlocked() and avoid the BUG_ON().
Fixes: a7c50c940477 ("block: pass a block_device and opf to bio_reset")
Signed-off-by: Coly Li <colyli@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220419160425.4148-2-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
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Secure erase is a very different operation from discard in that it is
a data integrity operation vs hint. Fully split the limits and helper
infrastructure to make the separation more clear.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> [drbd]
Acked-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> [nifs2]
Acked-by: Jaegeuk Kim <jaegeuk@kernel.org> [f2fs]
Acked-by: Coly Li <colyli@suse.de> [bcache]
Acked-by: David Sterba <dsterba@suse.com> [btrfs]
Acked-by: Chao Yu <chao@kernel.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220415045258.199825-27-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Just use a non-zero max_discard_sectors as an indicator for discard
support, similar to what is done for write zeroes.
The only places where needs special attention is the RAID5 driver,
which must clear discard support for security reasons by default,
even if the default stacking rules would allow for it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> [drbd]
Acked-by: Jan Höppner <hoeppner@linux.ibm.com> [s390]
Acked-by: Coly Li <colyli@suse.de> [bcache]
Acked-by: David Sterba <dsterba@suse.com> [btrfs]
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220415045258.199825-25-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Remove the magic autofree semantics and require the callers to explicitly
call bio_init to initialize the bio.
This allows bio_free to catch accidental bio_put calls on bio_init()ed
bios as well.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Coly Li <colyli@suse.de>
Acked-by: Mike Snitzer <snitzer@kernel.org>
Link: https://lore.kernel.org/r/20220406061228.410163-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core updates from Greg KH:
"Here is the set of driver core changes for 5.18-rc1.
Not much here, primarily it was a bunch of cleanups and small updates:
- kobj_type cleanups for default_groups
- documentation updates
- firmware loader minor changes
- component common helper added and take advantage of it in many
drivers (the largest part of this pull request).
All of these have been in linux-next for a while with no reported
problems"
* tag 'driver-core-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (54 commits)
Documentation: update stable review cycle documentation
drivers/base/dd.c : Remove the initial value of the global variable
Documentation: update stable tree link
Documentation: add link to stable release candidate tree
devres: fix typos in comments
Documentation: add note block surrounding security patch note
samples/kobject: Use sysfs_emit instead of sprintf
base: soc: Make soc_device_match() simpler and easier to read
driver core: dd: fix return value of __setup handler
driver core: Refactor sysfs and drv/bus remove hooks
driver core: Refactor multiple copies of device cleanup
scripts: get_abi.pl: Fix typo in help message
kernfs: fix typos in comments
kernfs: remove unneeded #if 0 guard
ALSA: hda/realtek: Make use of the helper component_compare_dev_name
video: omapfb: dss: Make use of the helper component_compare_dev
power: supply: ab8500: Make use of the helper component_compare_dev
ASoC: codecs: wcd938x: Make use of the helper component_compare/release_of
iommu/mediatek: Make use of the helper component_compare/release_of
drm: of: Make use of the helper component_release_of
...
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When multiple threads to check btree nodes in parallel, the main
thread wait for all threads to stop or CACHE_SET_IO_DISABLE flag:
wait_event_interruptible(check_state->wait,
atomic_read(&check_state->started) == 0 ||
test_bit(CACHE_SET_IO_DISABLE, &c->flags));
However, the bch_btree_node_read and bch_btree_node_read_done
maybe call bch_cache_set_error, then the CACHE_SET_IO_DISABLE
will be set. If the flag already set, the main thread return
error. At the same time, maybe some threads still running and
read NULL pointer, the kernel will crash.
This patch change the event wait condition, the main thread must
wait for all threads to stop.
Fixes: 8e7102273f597 ("bcache: make bch_btree_check() to be multithreaded")
Signed-off-by: Mingzhe Zou <mingzhe.zou@easystack.cn>
Cc: stable@vger.kernel.org # v5.7+
Signed-off-by: Coly Li <colyli@suse.de>
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When attaching a cached device (a.k.a backing device) to a cache
device, bch_sectors_dirty_init() is called to count dirty sectors
and stripes (see what bcache_dev_sectors_dirty_add() does) on the
cache device.
When bcache_dev_sectors_dirty_add() is called, set_bit(stripe,
d->full_dirty_stripes) or clear_bit(stripe, d->full_dirty_stripes)
operation will always be performed. In full_dirty_stripes, each 1bit
represents stripe_size (8192) sectors (512B), so 1bit=4MB (8192*512),
and each CPU cache line=64B=512bit=2048MB. When 20 threads process
a cached disk with 100G dirty data, a single thread processes about
23M at a time, and 20 threads total 460M. These full_dirty_stripes
bits corresponding to the 460M data is likely to fall in the same CPU
cache line. When one of these threads performs a set_bit or clear_bit
operation, the same CPU cache line of other threads will become invalid
and must read the full_dirty_stripes from the main memory again. Compared
with single thread, the time of a bcache_dev_sectors_dirty_add()
call is increased by about 50 times in our test (100G dirty data,
20 threads, bcache_dev_sectors_dirty_add() is called more than
20 million times).
This patch tries to test_bit before set_bit or clear_bit operation.
Therefore, a lot of force set and clear operations will be avoided,
and most of bcache_dev_sectors_dirty_add() calls will only read CPU
cache line.
Signed-off-by: Mingzhe Zou <mingzhe.zou@easystack.cn>
Signed-off-by: Coly Li <colyli@suse.de>
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Using local kmaps slightly reduces the chances to stray writes, and
the bvec interface cleans up the code a little bit.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/20220303111905.321089-8-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Pass a block_device to bio_clone_fast and __bio_clone_fast and give
the functions more suitable names.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220202160109.108149-14-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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