<feed xmlns='http://www.w3.org/2005/Atom'>
<title>blaster4385/linux-IllusionX/block, branch v6.12.10</title>
<subtitle>Linux kernel with personal config changes for arch linux</subtitle>
<id>https://git.tablaster.dev/blaster4385/linux-IllusionX/atom?h=v6.12.10</id>
<link rel='self' href='https://git.tablaster.dev/blaster4385/linux-IllusionX/atom?h=v6.12.10'/>
<link rel='alternate' type='text/html' href='https://git.tablaster.dev/blaster4385/linux-IllusionX/'/>
<updated>2025-01-17T12:40:59Z</updated>
<entry>
<title>block, bfq: fix waker_bfqq UAF after bfq_split_bfqq()</title>
<updated>2025-01-17T12:40:59Z</updated>
<author>
<name>Yu Kuai</name>
<email>yukuai3@huawei.com</email>
</author>
<published>2025-01-08T08:41:48Z</published>
<link rel='alternate' type='text/html' href='https://git.tablaster.dev/blaster4385/linux-IllusionX/commit/?id=bc2aeb35ff167e0c6b0cedf0c96a5c41e6cba1ed'/>
<id>urn:sha1:bc2aeb35ff167e0c6b0cedf0c96a5c41e6cba1ed</id>
<content type='text'>
[ Upstream commit fcede1f0a043ccefe9bc6ad57f12718e42f63f1d ]

Our syzkaller report a following UAF for v6.6:

BUG: KASAN: slab-use-after-free in bfq_init_rq+0x175d/0x17a0 block/bfq-iosched.c:6958
Read of size 8 at addr ffff8881b57147d8 by task fsstress/232726

CPU: 2 PID: 232726 Comm: fsstress Not tainted 6.6.0-g3629d1885222 #39
Call Trace:
 &lt;TASK&gt;
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x91/0xf0 lib/dump_stack.c:106
 print_address_description.constprop.0+0x66/0x300 mm/kasan/report.c:364
 print_report+0x3e/0x70 mm/kasan/report.c:475
 kasan_report+0xb8/0xf0 mm/kasan/report.c:588
 hlist_add_head include/linux/list.h:1023 [inline]
 bfq_init_rq+0x175d/0x17a0 block/bfq-iosched.c:6958
 bfq_insert_request.isra.0+0xe8/0xa20 block/bfq-iosched.c:6271
 bfq_insert_requests+0x27f/0x390 block/bfq-iosched.c:6323
 blk_mq_insert_request+0x290/0x8f0 block/blk-mq.c:2660
 blk_mq_submit_bio+0x1021/0x15e0 block/blk-mq.c:3143
 __submit_bio+0xa0/0x6b0 block/blk-core.c:639
 __submit_bio_noacct_mq block/blk-core.c:718 [inline]
 submit_bio_noacct_nocheck+0x5b7/0x810 block/blk-core.c:747
 submit_bio_noacct+0xca0/0x1990 block/blk-core.c:847
 __ext4_read_bh fs/ext4/super.c:205 [inline]
 ext4_read_bh+0x15e/0x2e0 fs/ext4/super.c:230
 __read_extent_tree_block+0x304/0x6f0 fs/ext4/extents.c:567
 ext4_find_extent+0x479/0xd20 fs/ext4/extents.c:947
 ext4_ext_map_blocks+0x1a3/0x2680 fs/ext4/extents.c:4182
 ext4_map_blocks+0x929/0x15a0 fs/ext4/inode.c:660
 ext4_iomap_begin_report+0x298/0x480 fs/ext4/inode.c:3569
 iomap_iter+0x3dd/0x1010 fs/iomap/iter.c:91
 iomap_fiemap+0x1f4/0x360 fs/iomap/fiemap.c:80
 ext4_fiemap+0x181/0x210 fs/ext4/extents.c:5051
 ioctl_fiemap.isra.0+0x1b4/0x290 fs/ioctl.c:220
 do_vfs_ioctl+0x31c/0x11a0 fs/ioctl.c:811
 __do_sys_ioctl fs/ioctl.c:869 [inline]
 __se_sys_ioctl+0xae/0x190 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x70/0x120 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x78/0xe2

Allocated by task 232719:
 kasan_save_stack+0x22/0x50 mm/kasan/common.c:45
 kasan_set_track+0x25/0x30 mm/kasan/common.c:52
 __kasan_slab_alloc+0x87/0x90 mm/kasan/common.c:328
 kasan_slab_alloc include/linux/kasan.h:188 [inline]
 slab_post_alloc_hook mm/slab.h:768 [inline]
 slab_alloc_node mm/slub.c:3492 [inline]
 kmem_cache_alloc_node+0x1b8/0x6f0 mm/slub.c:3537
 bfq_get_queue+0x215/0x1f00 block/bfq-iosched.c:5869
 bfq_get_bfqq_handle_split+0x167/0x5f0 block/bfq-iosched.c:6776
 bfq_init_rq+0x13a4/0x17a0 block/bfq-iosched.c:6938
 bfq_insert_request.isra.0+0xe8/0xa20 block/bfq-iosched.c:6271
 bfq_insert_requests+0x27f/0x390 block/bfq-iosched.c:6323
 blk_mq_insert_request+0x290/0x8f0 block/blk-mq.c:2660
 blk_mq_submit_bio+0x1021/0x15e0 block/blk-mq.c:3143
 __submit_bio+0xa0/0x6b0 block/blk-core.c:639
 __submit_bio_noacct_mq block/blk-core.c:718 [inline]
 submit_bio_noacct_nocheck+0x5b7/0x810 block/blk-core.c:747
 submit_bio_noacct+0xca0/0x1990 block/blk-core.c:847
 __ext4_read_bh fs/ext4/super.c:205 [inline]
 ext4_read_bh_nowait+0x15a/0x240 fs/ext4/super.c:217
 ext4_read_bh_lock+0xac/0xd0 fs/ext4/super.c:242
 ext4_bread_batch+0x268/0x500 fs/ext4/inode.c:958
 __ext4_find_entry+0x448/0x10f0 fs/ext4/namei.c:1671
 ext4_lookup_entry fs/ext4/namei.c:1774 [inline]
 ext4_lookup.part.0+0x359/0x6f0 fs/ext4/namei.c:1842
 ext4_lookup+0x72/0x90 fs/ext4/namei.c:1839
 __lookup_slow+0x257/0x480 fs/namei.c:1696
 lookup_slow fs/namei.c:1713 [inline]
 walk_component+0x454/0x5c0 fs/namei.c:2004
 link_path_walk.part.0+0x773/0xda0 fs/namei.c:2331
 link_path_walk fs/namei.c:3826 [inline]
 path_openat+0x1b9/0x520 fs/namei.c:3826
 do_filp_open+0x1b7/0x400 fs/namei.c:3857
 do_sys_openat2+0x5dc/0x6e0 fs/open.c:1428
 do_sys_open fs/open.c:1443 [inline]
 __do_sys_openat fs/open.c:1459 [inline]
 __se_sys_openat fs/open.c:1454 [inline]
 __x64_sys_openat+0x148/0x200 fs/open.c:1454
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x70/0x120 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x78/0xe2

Freed by task 232726:
 kasan_save_stack+0x22/0x50 mm/kasan/common.c:45
 kasan_set_track+0x25/0x30 mm/kasan/common.c:52
 kasan_save_free_info+0x2b/0x50 mm/kasan/generic.c:522
 ____kasan_slab_free mm/kasan/common.c:236 [inline]
 __kasan_slab_free+0x12a/0x1b0 mm/kasan/common.c:244
 kasan_slab_free include/linux/kasan.h:164 [inline]
 slab_free_hook mm/slub.c:1827 [inline]
 slab_free_freelist_hook mm/slub.c:1853 [inline]
 slab_free mm/slub.c:3820 [inline]
 kmem_cache_free+0x110/0x760 mm/slub.c:3842
 bfq_put_queue+0x6a7/0xfb0 block/bfq-iosched.c:5428
 bfq_forget_entity block/bfq-wf2q.c:634 [inline]
 bfq_put_idle_entity+0x142/0x240 block/bfq-wf2q.c:645
 bfq_forget_idle+0x189/0x1e0 block/bfq-wf2q.c:671
 bfq_update_vtime block/bfq-wf2q.c:1280 [inline]
 __bfq_lookup_next_entity block/bfq-wf2q.c:1374 [inline]
 bfq_lookup_next_entity+0x350/0x480 block/bfq-wf2q.c:1433
 bfq_update_next_in_service+0x1c0/0x4f0 block/bfq-wf2q.c:128
 bfq_deactivate_entity+0x10a/0x240 block/bfq-wf2q.c:1188
 bfq_deactivate_bfqq block/bfq-wf2q.c:1592 [inline]
 bfq_del_bfqq_busy+0x2e8/0xad0 block/bfq-wf2q.c:1659
 bfq_release_process_ref+0x1cc/0x220 block/bfq-iosched.c:3139
 bfq_split_bfqq+0x481/0xdf0 block/bfq-iosched.c:6754
 bfq_init_rq+0xf29/0x17a0 block/bfq-iosched.c:6934
 bfq_insert_request.isra.0+0xe8/0xa20 block/bfq-iosched.c:6271
 bfq_insert_requests+0x27f/0x390 block/bfq-iosched.c:6323
 blk_mq_insert_request+0x290/0x8f0 block/blk-mq.c:2660
 blk_mq_submit_bio+0x1021/0x15e0 block/blk-mq.c:3143
 __submit_bio+0xa0/0x6b0 block/blk-core.c:639
 __submit_bio_noacct_mq block/blk-core.c:718 [inline]
 submit_bio_noacct_nocheck+0x5b7/0x810 block/blk-core.c:747
 submit_bio_noacct+0xca0/0x1990 block/blk-core.c:847
 __ext4_read_bh fs/ext4/super.c:205 [inline]
 ext4_read_bh+0x15e/0x2e0 fs/ext4/super.c:230
 __read_extent_tree_block+0x304/0x6f0 fs/ext4/extents.c:567
 ext4_find_extent+0x479/0xd20 fs/ext4/extents.c:947
 ext4_ext_map_blocks+0x1a3/0x2680 fs/ext4/extents.c:4182
 ext4_map_blocks+0x929/0x15a0 fs/ext4/inode.c:660
 ext4_iomap_begin_report+0x298/0x480 fs/ext4/inode.c:3569
 iomap_iter+0x3dd/0x1010 fs/iomap/iter.c:91
 iomap_fiemap+0x1f4/0x360 fs/iomap/fiemap.c:80
 ext4_fiemap+0x181/0x210 fs/ext4/extents.c:5051
 ioctl_fiemap.isra.0+0x1b4/0x290 fs/ioctl.c:220
 do_vfs_ioctl+0x31c/0x11a0 fs/ioctl.c:811
 __do_sys_ioctl fs/ioctl.c:869 [inline]
 __se_sys_ioctl+0xae/0x190 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x70/0x120 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x78/0xe2

commit 1ba0403ac644 ("block, bfq: fix uaf for accessing waker_bfqq after
splitting") fix the problem that if waker_bfqq is in the merge chain,
and current is the only procress, waker_bfqq can be freed from
bfq_split_bfqq(). However, the case that waker_bfqq is not in the merge
chain is missed, and if the procress reference of waker_bfqq is 0,
waker_bfqq can be freed as well.

Fix the problem by checking procress reference if waker_bfqq is not in
the merge_chain.

Fixes: 1ba0403ac644 ("block, bfq: fix uaf for accessing waker_bfqq after splitting")
Signed-off-by: Hou Tao &lt;houtao1@huawei.com&gt;
Signed-off-by: Yu Kuai &lt;yukuai3@huawei.com&gt;
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Link: https://lore.kernel.org/r/20250108084148.1549973-1-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>block: lift bio_is_zone_append to bio.h</title>
<updated>2025-01-09T12:33:32Z</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2024-11-04T06:26:31Z</published>
<link rel='alternate' type='text/html' href='https://git.tablaster.dev/blaster4385/linux-IllusionX/commit/?id=2cf5d691f849be1a9474ac43190676f0dd5b151d'/>
<id>urn:sha1:2cf5d691f849be1a9474ac43190676f0dd5b151d</id>
<content type='text'>
[ Upstream commit 0ef2b9e698dbf9ba78f67952a747f35eb7060470 ]

Make bio_is_zone_append globally available, because file systems need
to use to check for a zone append bio in their end_io handlers to deal
with the block layer emulation.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Damien Le Moal &lt;dlemoal@kernel.org&gt;
Reviewed-by: Johannes Thumshirn &lt;johannes.thumshirn@wdc.com&gt;
Link: https://lore.kernel.org/r/20241104062647.91160-4-hch@lst.de
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Stable-dep-of: 6c3864e05548 ("btrfs: use bio_is_zone_append() in the completion handler")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>blk-mq: register cpuhp callback after hctx is added to xarray table</title>
<updated>2025-01-02T09:34:20Z</updated>
<author>
<name>Ming Lei</name>
<email>ming.lei@redhat.com</email>
</author>
<published>2024-12-06T11:16:06Z</published>
<link rel='alternate' type='text/html' href='https://git.tablaster.dev/blaster4385/linux-IllusionX/commit/?id=16b54ee81d8a44781ddeb5e577262d22c4e6c853'/>
<id>urn:sha1:16b54ee81d8a44781ddeb5e577262d22c4e6c853</id>
<content type='text'>
[ Upstream commit 4bf485a7db5d82ddd0f3ad2b299893199090375e ]

We need to retrieve 'hctx' from xarray table in the cpuhp callback, so the
callback should be registered after this 'hctx' is added to xarray table.

Cc: Reinette Chatre &lt;reinette.chatre@intel.com&gt;
Cc: Fenghua Yu &lt;fenghua.yu@intel.com&gt;
Cc: Peter Newman &lt;peternewman@google.com&gt;
Cc: Babu Moger &lt;babu.moger@amd.com&gt;
Cc: Luck Tony &lt;tony.luck@intel.com&gt;
Signed-off-by: Ming Lei &lt;ming.lei@redhat.com&gt;
Tested-by: Tony Luck &lt;tony.luck@intel.com&gt;
Link: https://lore.kernel.org/r/20241206111611.978870-2-ming.lei@redhat.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>block: avoid to reuse `hctx` not removed from cpuhp callback list</title>
<updated>2024-12-27T13:02:12Z</updated>
<author>
<name>Ming Lei</name>
<email>ming.lei@redhat.com</email>
</author>
<published>2024-12-18T10:16:15Z</published>
<link rel='alternate' type='text/html' href='https://git.tablaster.dev/blaster4385/linux-IllusionX/commit/?id=b5792c162dcf6197bf3d2de2be6c8169435b73d0'/>
<id>urn:sha1:b5792c162dcf6197bf3d2de2be6c8169435b73d0</id>
<content type='text'>
[ Upstream commit 85672ca9ceeaa1dcf2777a7048af5f4aee3fd02b ]

If the 'hctx' isn't removed from cpuhp callback list, we can't reuse it,
otherwise use-after-free may be triggered.

Reported-by: kernel test robot &lt;oliver.sang@intel.com&gt;
Closes: https://lore.kernel.org/oe-lkp/202412172217.b906db7c-lkp@intel.com
Tested-by: kernel test robot &lt;oliver.sang@intel.com&gt;
Fixes: 22465bbac53c ("blk-mq: move cpuhp callback registering out of q-&gt;sysfs_lock")
Signed-off-by: Ming Lei &lt;ming.lei@redhat.com&gt;
Link: https://lore.kernel.org/r/20241218101617.3275704-3-ming.lei@redhat.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>block: Revert "block: Fix potential deadlock while freezing queue and acquiring sysfs_lock"</title>
<updated>2024-12-27T13:02:07Z</updated>
<author>
<name>Ming Lei</name>
<email>ming.lei@redhat.com</email>
</author>
<published>2024-12-18T10:16:14Z</published>
<link rel='alternate' type='text/html' href='https://git.tablaster.dev/blaster4385/linux-IllusionX/commit/?id=97701315e32ed1b218399d41b16a57bcec6c77c0'/>
<id>urn:sha1:97701315e32ed1b218399d41b16a57bcec6c77c0</id>
<content type='text'>
commit 224749be6c23efe7fb8a030854f4fc5d1dd813b3 upstream.

This reverts commit be26ba96421ab0a8fa2055ccf7db7832a13c44d2.

Commit be26ba96421a ("block: Fix potential deadlock while freezing queue and
acquiring sysfs_loc") actually reverts commit 22465bbac53c ("blk-mq: move cpuhp
callback registering out of q-&gt;sysfs_lock"), and causes the original resctrl
lockdep warning.

So revert it and we need to fix the issue in another way.

Cc: Nilay Shroff &lt;nilay@linux.ibm.com&gt;
Fixes: be26ba96421a ("block: Fix potential deadlock while freezing queue and acquiring sysfs_loc")
Signed-off-by: Ming Lei &lt;ming.lei@redhat.com&gt;
Link: https://lore.kernel.org/r/20241218101617.3275704-2-ming.lei@redhat.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>block: Fix potential deadlock while freezing queue and acquiring sysfs_lock</title>
<updated>2024-12-19T17:13:22Z</updated>
<author>
<name>Nilay Shroff</name>
<email>nilay@linux.ibm.com</email>
</author>
<published>2024-12-10T14:41:43Z</published>
<link rel='alternate' type='text/html' href='https://git.tablaster.dev/blaster4385/linux-IllusionX/commit/?id=f1a494df8350da2e673618627cb392a8669825dd'/>
<id>urn:sha1:f1a494df8350da2e673618627cb392a8669825dd</id>
<content type='text'>
[ Upstream commit be26ba96421ab0a8fa2055ccf7db7832a13c44d2 ]

For storing a value to a queue attribute, the queue_attr_store function
first freezes the queue (-&gt;q_usage_counter(io)) and then acquire
-&gt;sysfs_lock. This seems not correct as the usual ordering should be to
acquire -&gt;sysfs_lock before freezing the queue. This incorrect ordering
causes the following lockdep splat which we are able to reproduce always
simply by accessing /sys/kernel/debug file using ls command:

[   57.597146] WARNING: possible circular locking dependency detected
[   57.597154] 6.12.0-10553-gb86545e02e8c #20 Tainted: G        W
[   57.597162] ------------------------------------------------------
[   57.597168] ls/4605 is trying to acquire lock:
[   57.597176] c00000003eb56710 (&amp;mm-&gt;mmap_lock){++++}-{4:4}, at: __might_fault+0x58/0xc0
[   57.597200]
               but task is already holding lock:
[   57.597207] c0000018e27c6810 (&amp;sb-&gt;s_type-&gt;i_mutex_key#3){++++}-{4:4}, at: iterate_dir+0x94/0x1d4
[   57.597226]
               which lock already depends on the new lock.

[   57.597233]
               the existing dependency chain (in reverse order) is:
[   57.597241]
               -&gt; #5 (&amp;sb-&gt;s_type-&gt;i_mutex_key#3){++++}-{4:4}:
[   57.597255]        down_write+0x6c/0x18c
[   57.597264]        start_creating+0xb4/0x24c
[   57.597274]        debugfs_create_dir+0x2c/0x1e8
[   57.597283]        blk_register_queue+0xec/0x294
[   57.597292]        add_disk_fwnode+0x2e4/0x548
[   57.597302]        brd_alloc+0x2c8/0x338
[   57.597309]        brd_init+0x100/0x178
[   57.597317]        do_one_initcall+0x88/0x3e4
[   57.597326]        kernel_init_freeable+0x3cc/0x6e0
[   57.597334]        kernel_init+0x34/0x1cc
[   57.597342]        ret_from_kernel_user_thread+0x14/0x1c
[   57.597350]
               -&gt; #4 (&amp;q-&gt;debugfs_mutex){+.+.}-{4:4}:
[   57.597362]        __mutex_lock+0xfc/0x12a0
[   57.597370]        blk_register_queue+0xd4/0x294
[   57.597379]        add_disk_fwnode+0x2e4/0x548
[   57.597388]        brd_alloc+0x2c8/0x338
[   57.597395]        brd_init+0x100/0x178
[   57.597402]        do_one_initcall+0x88/0x3e4
[   57.597410]        kernel_init_freeable+0x3cc/0x6e0
[   57.597418]        kernel_init+0x34/0x1cc
[   57.597426]        ret_from_kernel_user_thread+0x14/0x1c
[   57.597434]
               -&gt; #3 (&amp;q-&gt;sysfs_lock){+.+.}-{4:4}:
[   57.597446]        __mutex_lock+0xfc/0x12a0
[   57.597454]        queue_attr_store+0x9c/0x110
[   57.597462]        sysfs_kf_write+0x70/0xb0
[   57.597471]        kernfs_fop_write_iter+0x1b0/0x2ac
[   57.597480]        vfs_write+0x3dc/0x6e8
[   57.597488]        ksys_write+0x84/0x140
[   57.597495]        system_call_exception+0x130/0x360
[   57.597504]        system_call_common+0x160/0x2c4
[   57.597516]
               -&gt; #2 (&amp;q-&gt;q_usage_counter(io)#21){++++}-{0:0}:
[   57.597530]        __submit_bio+0x5ec/0x828
[   57.597538]        submit_bio_noacct_nocheck+0x1e4/0x4f0
[   57.597547]        iomap_readahead+0x2a0/0x448
[   57.597556]        xfs_vm_readahead+0x28/0x3c
[   57.597564]        read_pages+0x88/0x41c
[   57.597571]        page_cache_ra_unbounded+0x1ac/0x2d8
[   57.597580]        filemap_get_pages+0x188/0x984
[   57.597588]        filemap_read+0x13c/0x4bc
[   57.597596]        xfs_file_buffered_read+0x88/0x17c
[   57.597605]        xfs_file_read_iter+0xac/0x158
[   57.597614]        vfs_read+0x2d4/0x3b4
[   57.597622]        ksys_read+0x84/0x144
[   57.597629]        system_call_exception+0x130/0x360
[   57.597637]        system_call_common+0x160/0x2c4
[   57.597647]
               -&gt; #1 (mapping.invalidate_lock#2){++++}-{4:4}:
[   57.597661]        down_read+0x6c/0x220
[   57.597669]        filemap_fault+0x870/0x100c
[   57.597677]        xfs_filemap_fault+0xc4/0x18c
[   57.597684]        __do_fault+0x64/0x164
[   57.597693]        __handle_mm_fault+0x1274/0x1dac
[   57.597702]        handle_mm_fault+0x248/0x484
[   57.597711]        ___do_page_fault+0x428/0xc0c
[   57.597719]        hash__do_page_fault+0x30/0x68
[   57.597727]        do_hash_fault+0x90/0x35c
[   57.597736]        data_access_common_virt+0x210/0x220
[   57.597745]        _copy_from_user+0xf8/0x19c
[   57.597754]        sel_write_load+0x178/0xd54
[   57.597762]        vfs_write+0x108/0x6e8
[   57.597769]        ksys_write+0x84/0x140
[   57.597777]        system_call_exception+0x130/0x360
[   57.597785]        system_call_common+0x160/0x2c4
[   57.597794]
               -&gt; #0 (&amp;mm-&gt;mmap_lock){++++}-{4:4}:
[   57.597806]        __lock_acquire+0x17cc/0x2330
[   57.597814]        lock_acquire+0x138/0x400
[   57.597822]        __might_fault+0x7c/0xc0
[   57.597830]        filldir64+0xe8/0x390
[   57.597839]        dcache_readdir+0x80/0x2d4
[   57.597846]        iterate_dir+0xd8/0x1d4
[   57.597855]        sys_getdents64+0x88/0x2d4
[   57.597864]        system_call_exception+0x130/0x360
[   57.597872]        system_call_common+0x160/0x2c4
[   57.597881]
               other info that might help us debug this:

[   57.597888] Chain exists of:
                 &amp;mm-&gt;mmap_lock --&gt; &amp;q-&gt;debugfs_mutex --&gt; &amp;sb-&gt;s_type-&gt;i_mutex_key#3

[   57.597905]  Possible unsafe locking scenario:

[   57.597911]        CPU0                    CPU1
[   57.597917]        ----                    ----
[   57.597922]   rlock(&amp;sb-&gt;s_type-&gt;i_mutex_key#3);
[   57.597932]                                lock(&amp;q-&gt;debugfs_mutex);
[   57.597940]                                lock(&amp;sb-&gt;s_type-&gt;i_mutex_key#3);
[   57.597950]   rlock(&amp;mm-&gt;mmap_lock);
[   57.597958]
                *** DEADLOCK ***

[   57.597965] 2 locks held by ls/4605:
[   57.597971]  #0: c0000000137c12f8 (&amp;f-&gt;f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0xcc/0x154
[   57.597989]  #1: c0000018e27c6810 (&amp;sb-&gt;s_type-&gt;i_mutex_key#3){++++}-{4:4}, at: iterate_dir+0x94/0x1d4

Prevent the above lockdep warning by acquiring -&gt;sysfs_lock before
freezing the queue while storing a queue attribute in queue_attr_store
function. Later, we also found[1] another function __blk_mq_update_nr_
hw_queues where we first freeze queue and then acquire the -&gt;sysfs_lock.
So we've also updated lock ordering in __blk_mq_update_nr_hw_queues
function and ensured that in all code paths we follow the correct lock
ordering i.e. acquire -&gt;sysfs_lock before freezing the queue.

[1] https://lore.kernel.org/all/CAFj5m9Ke8+EHKQBs_Nk6hqd=LGXtk4mUxZUN5==ZcCjnZSBwHw@mail.gmail.com/

Reported-by: kjain@linux.ibm.com
Fixes: af2814149883 ("block: freeze the queue in queue_attr_store")
Tested-by: kjain@linux.ibm.com
Cc: hch@lst.de
Cc: axboe@kernel.dk
Cc: ritesh.list@gmail.com
Cc: ming.lei@redhat.com
Cc: gjoyce@linux.ibm.com
Signed-off-by: Nilay Shroff &lt;nilay@linux.ibm.com&gt;
Reviewed-by: Ming Lei &lt;ming.lei@redhat.com&gt;
Link: https://lore.kernel.org/r/20241210144222.1066229-1-nilay@linux.ibm.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>blk-mq: move cpuhp callback registering out of q-&gt;sysfs_lock</title>
<updated>2024-12-19T17:13:22Z</updated>
<author>
<name>Ming Lei</name>
<email>ming.lei@redhat.com</email>
</author>
<published>2024-12-06T11:16:07Z</published>
<link rel='alternate' type='text/html' href='https://git.tablaster.dev/blaster4385/linux-IllusionX/commit/?id=c1291ea131d186296dc8d328a36c3caf38e8e159'/>
<id>urn:sha1:c1291ea131d186296dc8d328a36c3caf38e8e159</id>
<content type='text'>
[ Upstream commit 22465bbac53c821319089016f268a2437de9b00a ]

Registering and unregistering cpuhp callback requires global cpu hotplug lock,
which is used everywhere. Meantime q-&gt;sysfs_lock is used in block layer
almost everywhere.

It is easy to trigger lockdep warning[1] by connecting the two locks.

Fix the warning by moving blk-mq's cpuhp callback registering out of
q-&gt;sysfs_lock. Add one dedicated global lock for covering registering &amp;
unregistering hctx's cpuhp, and it is safe to do so because hctx is
guaranteed to be live if our request_queue is live.

[1] https://lore.kernel.org/lkml/Z04pz3AlvI4o0Mr8@agluck-desk3/

Cc: Reinette Chatre &lt;reinette.chatre@intel.com&gt;
Cc: Fenghua Yu &lt;fenghua.yu@intel.com&gt;
Cc: Peter Newman &lt;peternewman@google.com&gt;
Cc: Babu Moger &lt;babu.moger@amd.com&gt;
Reported-by: Luck Tony &lt;tony.luck@intel.com&gt;
Signed-off-by: Ming Lei &lt;ming.lei@redhat.com&gt;
Tested-by: Tony Luck &lt;tony.luck@intel.com&gt;
Link: https://lore.kernel.org/r/20241206111611.978870-3-ming.lei@redhat.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Stable-dep-of: be26ba96421a ("block: Fix potential deadlock while freezing queue and acquiring sysfs_lock")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>blk-iocost: Avoid using clamp() on inuse in __propagate_weights()</title>
<updated>2024-12-19T17:13:22Z</updated>
<author>
<name>Nathan Chancellor</name>
<email>nathan@kernel.org</email>
</author>
<published>2024-12-12T17:13:29Z</published>
<link rel='alternate' type='text/html' href='https://git.tablaster.dev/blaster4385/linux-IllusionX/commit/?id=eea698975153f1c2d99a9af49ba6fa3a63cd1ab4'/>
<id>urn:sha1:eea698975153f1c2d99a9af49ba6fa3a63cd1ab4</id>
<content type='text'>
[ Upstream commit 57e420c84f9ab55ba4c5e2ae9c5f6c8e1ea834d2 ]

After a recent change to clamp() and its variants [1] that increases the
coverage of the check that high is greater than low because it can be
done through inlining, certain build configurations (such as s390
defconfig) fail to build with clang with:

  block/blk-iocost.c:1101:11: error: call to '__compiletime_assert_557' declared with 'error' attribute: clamp() low limit 1 greater than high limit active
   1101 |                 inuse = clamp_t(u32, inuse, 1, active);
        |                         ^
  include/linux/minmax.h:218:36: note: expanded from macro 'clamp_t'
    218 | #define clamp_t(type, val, lo, hi) __careful_clamp(type, val, lo, hi)
        |                                    ^
  include/linux/minmax.h:195:2: note: expanded from macro '__careful_clamp'
    195 |         __clamp_once(type, val, lo, hi, __UNIQUE_ID(v_), __UNIQUE_ID(l_), __UNIQUE_ID(h_))
        |         ^
  include/linux/minmax.h:188:2: note: expanded from macro '__clamp_once'
    188 |         BUILD_BUG_ON_MSG(statically_true(ulo &gt; uhi),                            \
        |         ^

__propagate_weights() is called with an active value of zero in
ioc_check_iocgs(), which results in the high value being less than the
low value, which is undefined because the value returned depends on the
order of the comparisons.

The purpose of this expression is to ensure inuse is not more than
active and at least 1. This could be written more simply with a ternary
expression that uses min(inuse, active) as the condition so that the
value of that condition can be used if it is not zero and one if it is.
Do this conversion to resolve the error and add a comment to deter
people from turning this back into clamp().

Fixes: 7caa47151ab2 ("blkcg: implement blk-iocost")
Link: https://lore.kernel.org/r/34d53778977747f19cce2abb287bb3e6@AcuMS.aculab.com/ [1]
Suggested-by: David Laight &lt;david.laight@aculab.com&gt;
Reported-by: Linux Kernel Functional Testing &lt;lkft@linaro.org&gt;
Closes: https://lore.kernel.org/llvm/CA+G9fYsD7mw13wredcZn0L-KBA3yeoVSTuxnss-AEWMN3ha0cA@mail.gmail.com/
Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Closes: https://lore.kernel.org/oe-kbuild-all/202412120322.3GfVe3vF-lkp@intel.com/
Signed-off-by: Nathan Chancellor &lt;nathan@kernel.org&gt;
Acked-by: Tejun Heo &lt;tj@kernel.org&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>block: get wp_offset by bdev_offset_from_zone_start</title>
<updated>2024-12-19T17:13:16Z</updated>
<author>
<name>LongPing Wei</name>
<email>weilongping@oppo.com</email>
</author>
<published>2024-11-07T02:04:41Z</published>
<link rel='alternate' type='text/html' href='https://git.tablaster.dev/blaster4385/linux-IllusionX/commit/?id=e7b02a0febbcd76b62c6827c52fed1d035713d0d'/>
<id>urn:sha1:e7b02a0febbcd76b62c6827c52fed1d035713d0d</id>
<content type='text'>
[ Upstream commit 790eb09e59709a1ffc1c64fe4aae2789120851b0 ]

Call bdev_offset_from_zone_start() instead of open-coding it.

Fixes: dd291d77cc90 ("block: Introduce zone write plugging")
Signed-off-by: LongPing Wei &lt;weilongping@oppo.com&gt;
Reviewed-by: Damien Le Moal &lt;dlemoal@kernel.org&gt;
Reviewed-by: Bart Van Assche &lt;bvanassche@acm.org&gt;
Link: https://lore.kernel.org/r/20241107020439.1644577-1-weilongping@oppo.com
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>block: Ignore REQ_NOWAIT for zone reset and zone finish operations</title>
<updated>2024-12-19T17:13:02Z</updated>
<author>
<name>Damien Le Moal</name>
<email>dlemoal@kernel.org</email>
</author>
<published>2024-12-09T12:23:55Z</published>
<link rel='alternate' type='text/html' href='https://git.tablaster.dev/blaster4385/linux-IllusionX/commit/?id=0eae680d03fb15b8a8f461b9a80b250b7b869e03'/>
<id>urn:sha1:0eae680d03fb15b8a8f461b9a80b250b7b869e03</id>
<content type='text'>
commit 5eb3317aa5a2ffe4574ab1a12cf9bc9447ca26c0 upstream.

There are currently any issuer of REQ_OP_ZONE_RESET and
REQ_OP_ZONE_FINISH operations that set REQ_NOWAIT. However, as we cannot
handle this flag correctly due to the potential request allocation
failure that may happen in blk_mq_submit_bio() after blk_zone_plug_bio()
has handled the zone write plug write pointer updates for the targeted
zones, modify blk_zone_wplug_handle_reset_or_finish() to warn if this
flag is set and ignore it.

Fixes: dd291d77cc90 ("block: Introduce zone write plugging")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal &lt;dlemoal@kernel.org&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Martin K. Petersen &lt;martin.petersen@oracle.com&gt;
Link: https://lore.kernel.org/r/20241209122357.47838-3-dlemoal@kernel.org
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
</feed>
