linux-toradex.git/drivers/md/raid0.c, branch v6.5-rc4 Linux kernel for Apalis and Colibri modules md/raid0: add discard support for the 'original' layout 2023-06-30T22:43:50+00:00 Jason Baron jbaron@akamai.com 2023-06-23T18:05:23+00:00 e836007089ba8fdf24e636ef2b007651fb4582e6 We've found that using raid0 with the 'original' layout and discard enabled with different disk sizes (such that at least two zones are created) can result in data corruption. This is due to the fact that the discard handling in 'raid0_handle_discard()' assumes the 'alternate' layout. We've seen this corruption using ext4 but other filesystems are likely susceptible as well. More specifically, while multiple zones are necessary to create the corruption, the corruption may not occur with multiple zones if they layout in such a way the layout matches what the 'alternate' layout would have produced. Thus, not all raid0 devices with the 'original' layout, different size disks and discard enabled will encounter this corruption. The 3.14 kernel inadvertently changed the raid0 disk layout for different size disks. Thus, running a pre-3.14 kernel and post-3.14 kernel on the same raid0 array could corrupt data. This lead to the creation of the 'original' layout (to match the pre-3.14 layout) and the 'alternate' layout (to match the post 3.14 layout) in the 5.4 kernel time frame and an option to tell the kernel which layout to use (since it couldn't be autodetected). However, when the 'original' layout was added back to 5.4 discard support for the 'original' layout was not added leading this issue. I've been able to reliably reproduce the corruption with the following test case: 1. create raid0 array with different size disks using original layout 2. mkfs 3. mount -o discard 4. create lots of files 5. remove 1/2 the files 6. fstrim -a (or just the mount point for the raid0 array) 7. umount 8. fsck -fn /dev/md0 (spews all sorts of corruptions) Let's fix this by adding proper discard support to the 'original' layout. The fix 'maps' the 'original' layout disks to the order in which they are read/written such that we can compare the disks in the same way that the current 'alternate' layout does. A 'disk_shift' field is added to 'struct strip_zone'. This could be computed on the fly in raid0_handle_discard() but by adding this field, we save some computation in the discard path. Note we could also potentially fix this by re-ordering the disks in the zones that follow the first one, and then always read/writing them using the 'alternate' layout. However, that is seen as a more substantial change, and we are attempting the least invasive fix at this time to remedy the corruption. I've verified the change using the reproducer mentioned above. Typically, the corruption is seen after less than 3 iterations, while the patch has run 500+ iterations. Cc: NeilBrown <neilb@suse.de> Cc: Song Liu <song@kernel.org> Fixes: c84a1372df92 ("md/raid0: avoid RAID0 data corruption due to layout confusion.") Cc: stable@vger.kernel.org Signed-off-by: Jason Baron <jbaron@akamai.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230623180523.1901230-1-jbaron@akamai.com 
We've found that using raid0 with the 'original' layout and discard
enabled with different disk sizes (such that at least two zones are
created) can result in data corruption. This is due to the fact that
the discard handling in 'raid0_handle_discard()' assumes the 'alternate'
layout. We've seen this corruption using ext4 but other filesystems are
likely susceptible as well.

More specifically, while multiple zones are necessary to create the
corruption, the corruption may not occur with multiple zones if they
layout in such a way the layout matches what the 'alternate' layout
would have produced. Thus, not all raid0 devices with the 'original'
layout, different size disks and discard enabled will encounter this
corruption.

The 3.14 kernel inadvertently changed the raid0 disk layout for different
size disks. Thus, running a pre-3.14 kernel and post-3.14 kernel on the
same raid0 array could corrupt data. This lead to the creation of the
'original' layout (to match the pre-3.14 layout) and the 'alternate' layout
(to match the post 3.14 layout) in the 5.4 kernel time frame and an option
to tell the kernel which layout to use (since it couldn't be autodetected).
However, when the 'original' layout was added back to 5.4 discard support
for the 'original' layout was not added leading this issue.

I've been able to reliably reproduce the corruption with the following
test case:

1. create raid0 array with different size disks using original layout
2. mkfs
3. mount -o discard
4. create lots of files
5. remove 1/2 the files
6. fstrim -a (or just the mount point for the raid0 array)
7. umount
8. fsck -fn /dev/md0 (spews all sorts of corruptions)

Let's fix this by adding proper discard support to the 'original' layout.
The fix 'maps' the 'original' layout disks to the order in which they are
read/written such that we can compare the disks in the same way that the
current 'alternate' layout does. A 'disk_shift' field is added to
'struct strip_zone'. This could be computed on the fly in
raid0_handle_discard() but by adding this field, we save some computation
in the discard path.

Note we could also potentially fix this by re-ordering the disks in the
zones that follow the first one, and then always read/writing them using
the 'alternate' layout. However, that is seen as a more substantial change,
and we are attempting the least invasive fix at this time to remedy the
corruption.

I've verified the change using the reproducer mentioned above. Typically,
the corruption is seen after less than 3 iterations, while the patch has
run 500+ iterations.

Cc: NeilBrown <neilb@suse.de>
Cc: Song Liu <song@kernel.org>
Fixes: c84a1372df92 ("md/raid0: avoid RAID0 data corruption due to layout confusion.")
Cc: stable@vger.kernel.org
Signed-off-by: Jason Baron <jbaron@akamai.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230623180523.1901230-1-jbaron@akamai.com
md: add error_handlers for raid0 and linear 2023-04-14T05:20:24+00:00 Mariusz Tkaczyk mariusz.tkaczyk@linux.intel.com 2023-03-06T13:03:17+00:00 c31fea2f8e2a72c817f318016bbc327095175a9f After the commit 9631abdbf406c("md: Set MD_BROKEN for RAID1 and RAID10") MD_BROKEN must be set if array is failed because state_store() checks it. If it is set then -EBUSY is returned to userspace. For raid0 and linear MD_BROKEN is not set by error_handler(). As a result mdadm is unable to trigger clean-up actions. It is a regression. This patch adds appropriate error_handler for raid0 and linear. The error handler sets MD_BROKEN for this device. Reviewed-by: Xiao Ni <xni@redhat.com> Signed-off-by: Mariusz Tkaczyk <mariusz.tkaczyk@linux.intel.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230306130317.3418-1-mariusz.tkaczyk@linux.intel.com 
After the commit 9631abdbf406c("md: Set MD_BROKEN for RAID1 and RAID10")
MD_BROKEN must be set if array is failed because state_store() checks it.
If it is set then -EBUSY is returned to userspace.

For raid0 and linear MD_BROKEN is not set by error_handler(). As a result
mdadm is unable to trigger clean-up actions. It is a regression.

This patch adds appropriate error_handler for raid0 and linear. The
error handler sets MD_BROKEN for this device.

Reviewed-by: Xiao Ni <xni@redhat.com>
Signed-off-by: Mariusz Tkaczyk <mariusz.tkaczyk@linux.intel.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230306130317.3418-1-mariusz.tkaczyk@linux.intel.com
md/raid0, raid10: Don't set discard sectors for request queue 2022-11-14T18:15:34+00:00 Xiao Ni xni@redhat.com 2022-11-02T02:07:30+00:00 8e1a2279ca2b0485cc379a153d02a9793f74a48f It should use disk_stack_limits to get a proper max_discard_sectors rather than setting a value by stack drivers. And there is a bug. If all member disks are rotational devices, raid0/raid10 set max_discard_sectors. So the member devices are not ssd/nvme, but raid0/raid10 export the wrong value. It reports warning messages in function __blkdev_issue_discard when mkfs.xfs like this: [ 4616.022599] ------------[ cut here ]------------ [ 4616.027779] WARNING: CPU: 4 PID: 99634 at block/blk-lib.c:50 __blkdev_issue_discard+0x16a/0x1a0 [ 4616.140663] RIP: 0010:__blkdev_issue_discard+0x16a/0x1a0 [ 4616.146601] Code: 24 4c 89 20 31 c0 e9 fe fe ff ff c1 e8 09 8d 48 ff 4c 89 f0 4c 09 e8 48 85 c1 0f 84 55 ff ff ff b8 ea ff ff ff e9 df fe ff ff <0f> 0b 48 8d 74 24 08 e8 ea d6 00 00 48 c7 c6 20 1e 89 ab 48 c7 c7 [ 4616.167567] RSP: 0018:ffffaab88cbffca8 EFLAGS: 00010246 [ 4616.173406] RAX: ffff9ba1f9e44678 RBX: 0000000000000000 RCX: ffff9ba1c9792080 [ 4616.181376] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff9ba1c9792080 [ 4616.189345] RBP: 0000000000000cc0 R08: ffffaab88cbffd10 R09: 0000000000000000 [ 4616.197317] R10: 0000000000000012 R11: 0000000000000000 R12: 0000000000000000 [ 4616.205288] R13: 0000000000400000 R14: 0000000000000cc0 R15: ffff9ba1c9792080 [ 4616.213259] FS: 00007f9a5534e980(0000) GS:ffff9ba1b7c80000(0000) knlGS:0000000000000000 [ 4616.222298] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 4616.228719] CR2: 000055a390a4c518 CR3: 0000000123e40006 CR4: 00000000001706e0 [ 4616.236689] Call Trace: [ 4616.239428] blkdev_issue_discard+0x52/0xb0 [ 4616.244108] blkdev_common_ioctl+0x43c/0xa00 [ 4616.248883] blkdev_ioctl+0x116/0x280 [ 4616.252977] __x64_sys_ioctl+0x8a/0xc0 [ 4616.257163] do_syscall_64+0x5c/0x90 [ 4616.261164] ? handle_mm_fault+0xc5/0x2a0 [ 4616.265652] ? do_user_addr_fault+0x1d8/0x690 [ 4616.270527] ? do_syscall_64+0x69/0x90 [ 4616.274717] ? exc_page_fault+0x62/0x150 [ 4616.279097] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 4616.284748] RIP: 0033:0x7f9a55398c6b Signed-off-by: Xiao Ni <xni@redhat.com> Reported-by: Yi Zhang <yi.zhang@redhat.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Song Liu <song@kernel.org> 
It should use disk_stack_limits to get a proper max_discard_sectors
rather than setting a value by stack drivers.

And there is a bug. If all member disks are rotational devices,
raid0/raid10 set max_discard_sectors. So the member devices are
not ssd/nvme, but raid0/raid10 export the wrong value. It reports
warning messages in function __blkdev_issue_discard when mkfs.xfs
like this:

[ 4616.022599] ------------[ cut here ]------------
[ 4616.027779] WARNING: CPU: 4 PID: 99634 at block/blk-lib.c:50 __blkdev_issue_discard+0x16a/0x1a0
[ 4616.140663] RIP: 0010:__blkdev_issue_discard+0x16a/0x1a0
[ 4616.146601] Code: 24 4c 89 20 31 c0 e9 fe fe ff ff c1 e8 09 8d 48 ff 4c 89 f0 4c 09 e8 48 85 c1 0f 84 55 ff ff ff b8 ea ff ff ff e9 df fe ff ff <0f> 0b 48 8d 74 24 08 e8 ea d6 00 00 48 c7 c6 20 1e 89 ab 48 c7 c7
[ 4616.167567] RSP: 0018:ffffaab88cbffca8 EFLAGS: 00010246
[ 4616.173406] RAX: ffff9ba1f9e44678 RBX: 0000000000000000 RCX: ffff9ba1c9792080
[ 4616.181376] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff9ba1c9792080
[ 4616.189345] RBP: 0000000000000cc0 R08: ffffaab88cbffd10 R09: 0000000000000000
[ 4616.197317] R10: 0000000000000012 R11: 0000000000000000 R12: 0000000000000000
[ 4616.205288] R13: 0000000000400000 R14: 0000000000000cc0 R15: ffff9ba1c9792080
[ 4616.213259] FS:  00007f9a5534e980(0000) GS:ffff9ba1b7c80000(0000) knlGS:0000000000000000
[ 4616.222298] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 4616.228719] CR2: 000055a390a4c518 CR3: 0000000123e40006 CR4: 00000000001706e0
[ 4616.236689] Call Trace:
[ 4616.239428]  blkdev_issue_discard+0x52/0xb0
[ 4616.244108]  blkdev_common_ioctl+0x43c/0xa00
[ 4616.248883]  blkdev_ioctl+0x116/0x280
[ 4616.252977]  __x64_sys_ioctl+0x8a/0xc0
[ 4616.257163]  do_syscall_64+0x5c/0x90
[ 4616.261164]  ? handle_mm_fault+0xc5/0x2a0
[ 4616.265652]  ? do_user_addr_fault+0x1d8/0x690
[ 4616.270527]  ? do_syscall_64+0x69/0x90
[ 4616.274717]  ? exc_page_fault+0x62/0x150
[ 4616.279097]  entry_SYSCALL_64_after_hwframe+0x63/0xcd
[ 4616.284748] RIP: 0033:0x7f9a55398c6b

Signed-off-by: Xiao Ni <xni@redhat.com>
Reported-by: Yi Zhang <yi.zhang@redhat.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Song Liu <song@kernel.org>
md: Replace snprintf with scnprintf 2022-09-22T07:05:03+00:00 Saurabh Sengar ssengar@linux.microsoft.com 2022-08-23T18:51:04+00:00 1727fd5015d8f93474148f94e34cda5aa6ad4a43 Current code produces a warning as shown below when total characters in the constituent block device names plus the slashes exceeds 200. snprintf() returns the number of characters generated from the given input, which could cause the expression “200 – len” to wrap around to a large positive number. Fix this by using scnprintf() instead, which returns the actual number of characters written into the buffer. [ 1513.267938] ------------[ cut here ]------------ [ 1513.267943] WARNING: CPU: 15 PID: 37247 at <snip>/lib/vsprintf.c:2509 vsnprintf+0x2c8/0x510 [ 1513.267944] Modules linked in: <snip> [ 1513.267969] CPU: 15 PID: 37247 Comm: mdadm Not tainted 5.4.0-1085-azure #90~18.04.1-Ubuntu [ 1513.267969] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.1 05/09/2022 [ 1513.267971] RIP: 0010:vsnprintf+0x2c8/0x510 <-snip-> [ 1513.267982] Call Trace: [ 1513.267986] snprintf+0x45/0x70 [ 1513.267990] ? disk_name+0x71/0xa0 [ 1513.267993] dump_zones+0x114/0x240 [raid0] [ 1513.267996] ? _cond_resched+0x19/0x40 [ 1513.267998] raid0_run+0x19e/0x270 [raid0] [ 1513.268000] md_run+0x5e0/0xc50 [ 1513.268003] ? security_capable+0x3f/0x60 [ 1513.268005] do_md_run+0x19/0x110 [ 1513.268006] md_ioctl+0x195e/0x1f90 [ 1513.268007] blkdev_ioctl+0x91f/0x9f0 [ 1513.268010] block_ioctl+0x3d/0x50 [ 1513.268012] do_vfs_ioctl+0xa9/0x640 [ 1513.268014] ? __fput+0x162/0x260 [ 1513.268016] ksys_ioctl+0x75/0x80 [ 1513.268017] __x64_sys_ioctl+0x1a/0x20 [ 1513.268019] do_syscall_64+0x5e/0x200 [ 1513.268021] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fixes: 766038846e875 ("md/raid0: replace printk() with pr_*()") Reviewed-by: Michael Kelley <mikelley@microsoft.com> Acked-by: Guoqing Jiang <guoqing.jiang@linux.dev> Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com> Signed-off-by: Song Liu <song@kernel.org> 
Current code produces a warning as shown below when total characters
in the constituent block device names plus the slashes exceeds 200.
snprintf() returns the number of characters generated from the given
input, which could cause the expression “200 – len” to wrap around
to a large positive number. Fix this by using scnprintf() instead,
which returns the actual number of characters written into the buffer.

[ 1513.267938] ------------[ cut here ]------------
[ 1513.267943] WARNING: CPU: 15 PID: 37247 at <snip>/lib/vsprintf.c:2509 vsnprintf+0x2c8/0x510
[ 1513.267944] Modules linked in:  <snip>
[ 1513.267969] CPU: 15 PID: 37247 Comm: mdadm Not tainted 5.4.0-1085-azure #90~18.04.1-Ubuntu
[ 1513.267969] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.1 05/09/2022
[ 1513.267971] RIP: 0010:vsnprintf+0x2c8/0x510
<-snip->
[ 1513.267982] Call Trace:
[ 1513.267986]  snprintf+0x45/0x70
[ 1513.267990]  ? disk_name+0x71/0xa0
[ 1513.267993]  dump_zones+0x114/0x240 [raid0]
[ 1513.267996]  ? _cond_resched+0x19/0x40
[ 1513.267998]  raid0_run+0x19e/0x270 [raid0]
[ 1513.268000]  md_run+0x5e0/0xc50
[ 1513.268003]  ? security_capable+0x3f/0x60
[ 1513.268005]  do_md_run+0x19/0x110
[ 1513.268006]  md_ioctl+0x195e/0x1f90
[ 1513.268007]  blkdev_ioctl+0x91f/0x9f0
[ 1513.268010]  block_ioctl+0x3d/0x50
[ 1513.268012]  do_vfs_ioctl+0xa9/0x640
[ 1513.268014]  ? __fput+0x162/0x260
[ 1513.268016]  ksys_ioctl+0x75/0x80
[ 1513.268017]  __x64_sys_ioctl+0x1a/0x20
[ 1513.268019]  do_syscall_64+0x5e/0x200
[ 1513.268021]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: 766038846e875 ("md/raid0: replace printk() with pr_*()")
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Acked-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Signed-off-by: Song Liu <song@kernel.org>
md: Don't set mddev private to NULL in raid0 pers->free 2022-05-23T06:07:21+00:00 Xiao Ni xni@redhat.com 2022-05-12T09:21:08+00:00 0f2571ad7a30ff6b33cde142439f9378669f8b4f In normal stop process, it does like this: do_md_stop | __md_stop (pers->free(); mddev->private=NULL) | md_free (free mddev) __md_stop sets mddev->private to NULL after pers->free. The raid device will be stopped and mddev memory is free. But in reshape, it doesn't free the mddev and mddev will still be used in new raid. In reshape, it first sets mddev->private to new_pers and then runs old_pers->free(). Now raid0 sets mddev->private to NULL in raid0_free. The new raid can't work anymore. It will panic when dereference mddev->private because of NULL pointer dereference. It can panic like this: [63010.814972] kernel BUG at drivers/md/raid10.c:928! [63010.819778] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI [63010.825011] CPU: 3 PID: 44437 Comm: md0_resync Kdump: loaded Not tainted 5.14.0-86.el9.x86_64 #1 [63010.833789] Hardware name: Dell Inc. PowerEdge R6415/07YXFK, BIOS 1.15.0 09/11/2020 [63010.841440] RIP: 0010:raise_barrier+0x161/0x170 [raid10] [63010.865508] RSP: 0018:ffffc312408bbc10 EFLAGS: 00010246 [63010.870734] RAX: 0000000000000000 RBX: ffffa00bf7d39800 RCX: 0000000000000000 [63010.877866] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffa00bf7d39800 [63010.884999] RBP: 0000000000000000 R08: fffffa4945e74400 R09: 0000000000000000 [63010.892132] R10: ffffa00eed02f798 R11: 0000000000000000 R12: ffffa00bbc435200 [63010.899266] R13: ffffa00bf7d39800 R14: 0000000000000400 R15: 0000000000000003 [63010.906399] FS: 0000000000000000(0000) GS:ffffa00eed000000(0000) knlGS:0000000000000000 [63010.914485] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [63010.920229] CR2: 00007f5cfbe99828 CR3: 0000000105efe000 CR4: 00000000003506e0 [63010.927363] Call Trace: [63010.929822] ? bio_reset+0xe/0x40 [63010.933144] ? raid10_alloc_init_r10buf+0x60/0xa0 [raid10] [63010.938629] raid10_sync_request+0x756/0x1610 [raid10] [63010.943770] md_do_sync.cold+0x3e4/0x94c [63010.947698] md_thread+0xab/0x160 [63010.951024] ? md_write_inc+0x50/0x50 [63010.954688] kthread+0x149/0x170 [63010.957923] ? set_kthread_struct+0x40/0x40 [63010.962107] ret_from_fork+0x22/0x30 Removing the code that sets mddev->private to NULL in raid0 can fix problem. Fixes: 0c031fd37f69 (md: Move alloc/free acct bioset in to personality) Reported-by: Fine Fan <ffan@redhat.com> Signed-off-by: Xiao Ni <xni@redhat.com> Signed-off-by: Song Liu <song@kernel.org> 
In normal stop process, it does like this:
   do_md_stop
      |
   __md_stop (pers->free(); mddev->private=NULL)
      |
   md_free (free mddev)
__md_stop sets mddev->private to NULL after pers->free. The raid device
will be stopped and mddev memory is free. But in reshape, it doesn't
free the mddev and mddev will still be used in new raid.

In reshape, it first sets mddev->private to new_pers and then runs
old_pers->free(). Now raid0 sets mddev->private to NULL in raid0_free.
The new raid can't work anymore. It will panic when dereference
mddev->private because of NULL pointer dereference.

It can panic like this:
[63010.814972] kernel BUG at drivers/md/raid10.c:928!
[63010.819778] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
[63010.825011] CPU: 3 PID: 44437 Comm: md0_resync Kdump: loaded Not tainted 5.14.0-86.el9.x86_64 #1
[63010.833789] Hardware name: Dell Inc. PowerEdge R6415/07YXFK, BIOS 1.15.0 09/11/2020
[63010.841440] RIP: 0010:raise_barrier+0x161/0x170 [raid10]
[63010.865508] RSP: 0018:ffffc312408bbc10 EFLAGS: 00010246
[63010.870734] RAX: 0000000000000000 RBX: ffffa00bf7d39800 RCX: 0000000000000000
[63010.877866] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffa00bf7d39800
[63010.884999] RBP: 0000000000000000 R08: fffffa4945e74400 R09: 0000000000000000
[63010.892132] R10: ffffa00eed02f798 R11: 0000000000000000 R12: ffffa00bbc435200
[63010.899266] R13: ffffa00bf7d39800 R14: 0000000000000400 R15: 0000000000000003
[63010.906399] FS:  0000000000000000(0000) GS:ffffa00eed000000(0000) knlGS:0000000000000000
[63010.914485] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[63010.920229] CR2: 00007f5cfbe99828 CR3: 0000000105efe000 CR4: 00000000003506e0
[63010.927363] Call Trace:
[63010.929822]  ? bio_reset+0xe/0x40
[63010.933144]  ? raid10_alloc_init_r10buf+0x60/0xa0 [raid10]
[63010.938629]  raid10_sync_request+0x756/0x1610 [raid10]
[63010.943770]  md_do_sync.cold+0x3e4/0x94c
[63010.947698]  md_thread+0xab/0x160
[63010.951024]  ? md_write_inc+0x50/0x50
[63010.954688]  kthread+0x149/0x170
[63010.957923]  ? set_kthread_struct+0x40/0x40
[63010.962107]  ret_from_fork+0x22/0x30

Removing the code that sets mddev->private to NULL in raid0 can fix
problem.

Fixes: 0c031fd37f69 (md: Move alloc/free acct bioset in to personality)
Reported-by: Fine Fan <ffan@redhat.com>
Signed-off-by: Xiao Ni <xni@redhat.com>
Signed-off-by: Song Liu <song@kernel.org>
md: remove most calls to bdevname 2022-05-23T06:07:21+00:00 Christoph Hellwig hch@lst.de 2022-05-12T06:19:13+00:00 913cce5a1e588e3470ea064fe4ea336037d3a454 Use the %pg format specifier to save on stack consumption and code size. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Song Liu <song@kernel.org> 
Use the %pg format specifier to save on stack consumption and code size.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Song Liu <song@kernel.org>
md/raid0: Ignore RAID0 layout if the second zone has only one device 2022-04-25T21:00:37+00:00 Pascal Hambourg pascal@plouf.fr.eu.org 2022-04-13T06:53:56+00:00 ea23994edc4169bd90d7a9b5908c6ccefd82fa40 The RAID0 layout is irrelevant if all members have the same size so the array has only one zone. It is *also* irrelevant if the array has two zones and the second zone has only one device, for example if the array has two members of different sizes. So in that case it makes sense to allow assembly even when the layout is undefined, like what is done when the array has only one zone. Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Pascal Hambourg <pascal@plouf.fr.eu.org> Signed-off-by: Song Liu <song@kernel.org> 
The RAID0 layout is irrelevant if all members have the same size so the
array has only one zone. It is *also* irrelevant if the array has two
zones and the second zone has only one device, for example if the array
has two members of different sizes.

So in that case it makes sense to allow assembly even when the layout is
undefined, like what is done when the array has only one zone.

Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Pascal Hambourg <pascal@plouf.fr.eu.org>
Signed-off-by: Song Liu <song@kernel.org>
block: remove QUEUE_FLAG_DISCARD 2022-04-18T01:49:59+00:00 Christoph Hellwig hch@lst.de 2022-04-15T04:52:55+00:00 70200574cc229f6ba038259e8142af2aa09e6976 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> 
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>
scsi: md: Remove WRITE_SAME support 2022-02-23T02:11:08+00:00 Christoph Hellwig hch@lst.de 2022-02-09T08:28:26+00:00 10fa225c33a97385f2843e60b8e86b0ce0cd1e5f There are no more end-users of REQ_OP_WRITE_SAME left, so we can start deleting it. Link: https://lore.kernel.org/r/20220209082828.2629273-6-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> 
There are no more end-users of REQ_OP_WRITE_SAME left, so we can start
deleting it.

Link: https://lore.kernel.org/r/20220209082828.2629273-6-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
md: Move alloc/free acct bioset in to personality 2022-01-06T16:37:03+00:00 Xiao Ni xni@redhat.com 2021-12-10T09:31:15+00:00 0c031fd37f69deb0cd8c43bbfcfccd62ebd7e952 bioset acct is only needed for raid0 and raid5. Therefore, md_run only allocates it for raid0 and raid5. However, this does not cover personality takeover, which may cause uninitialized bioset. For example, the following repro steps: mdadm -CR /dev/md0 -l1 -n2 /dev/loop0 /dev/loop1 mdadm --wait /dev/md0 mkfs.xfs /dev/md0 mdadm /dev/md0 --grow -l5 mount /dev/md0 /mnt causes panic like: [ 225.933939] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 225.934903] #PF: supervisor instruction fetch in kernel mode [ 225.935639] #PF: error_code(0x0010) - not-present page [ 225.936361] PGD 0 P4D 0 [ 225.936677] Oops: 0010 [#1] PREEMPT SMP DEBUG_PAGEALLOC KASAN PTI [ 225.937525] CPU: 27 PID: 1133 Comm: mount Not tainted 5.16.0-rc3+ #706 [ 225.938416] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-2.module_el8.4.0+547+a85d02ba 04/01/2014 [ 225.939922] RIP: 0010:0x0 [ 225.940289] Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6. [ 225.941196] RSP: 0018:ffff88815897eff0 EFLAGS: 00010246 [ 225.941897] RAX: 0000000000000000 RBX: 0000000000092800 RCX: ffffffff81370a39 [ 225.942813] RDX: dffffc0000000000 RSI: 0000000000000000 RDI: 0000000000092800 [ 225.943772] RBP: 1ffff1102b12fe04 R08: fffffbfff0b43c01 R09: fffffbfff0b43c01 [ 225.944807] R10: ffffffff85a1e007 R11: fffffbfff0b43c00 R12: ffff88810eaaaf58 [ 225.945757] R13: 0000000000000000 R14: ffff88810eaaafb8 R15: ffff88815897f040 [ 225.946709] FS: 00007ff3f2505080(0000) GS:ffff888fb5e00000(0000) knlGS:0000000000000000 [ 225.947814] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 225.948556] CR2: ffffffffffffffd6 CR3: 000000015aa5a006 CR4: 0000000000370ee0 [ 225.949537] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 225.950455] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 225.951414] Call Trace: [ 225.951787] <TASK> [ 225.952120] mempool_alloc+0xe5/0x250 [ 225.952625] ? mempool_resize+0x370/0x370 [ 225.953187] ? rcu_read_lock_sched_held+0xa1/0xd0 [ 225.953862] ? rcu_read_lock_bh_held+0xb0/0xb0 [ 225.954464] ? sched_clock_cpu+0x15/0x120 [ 225.955019] ? find_held_lock+0xac/0xd0 [ 225.955564] bio_alloc_bioset+0x1ed/0x2a0 [ 225.956080] ? lock_downgrade+0x3a0/0x3a0 [ 225.956644] ? bvec_alloc+0xc0/0xc0 [ 225.957135] bio_clone_fast+0x19/0x80 [ 225.957651] raid5_make_request+0x1370/0x1b70 [ 225.958286] ? sched_clock_cpu+0x15/0x120 [ 225.958797] ? __lock_acquire+0x8b2/0x3510 [ 225.959339] ? raid5_get_active_stripe+0xce0/0xce0 [ 225.959986] ? lock_is_held_type+0xd8/0x130 [ 225.960528] ? rcu_read_lock_sched_held+0xa1/0xd0 [ 225.961135] ? rcu_read_lock_bh_held+0xb0/0xb0 [ 225.961703] ? sched_clock_cpu+0x15/0x120 [ 225.962232] ? lock_release+0x27a/0x6c0 [ 225.962746] ? do_wait_intr_irq+0x130/0x130 [ 225.963302] ? lock_downgrade+0x3a0/0x3a0 [ 225.963815] ? lock_release+0x6c0/0x6c0 [ 225.964348] md_handle_request+0x342/0x530 [ 225.964888] ? set_in_sync+0x170/0x170 [ 225.965397] ? blk_queue_split+0x133/0x150 [ 225.965988] ? __blk_queue_split+0x8b0/0x8b0 [ 225.966524] ? submit_bio_checks+0x3b2/0x9d0 [ 225.967069] md_submit_bio+0x127/0x1c0 [...] Fix this by moving alloc/free of acct bioset to pers->run and pers->free. While we are on this, properly handle md_integrity_register() error in raid0_run(). Fixes: daee2024715d (md: check level before create and exit io_acct_set) Cc: stable@vger.kernel.org Acked-by: Guoqing Jiang <guoqing.jiang@linux.dev> Signed-off-by: Xiao Ni <xni@redhat.com> Signed-off-by: Song Liu <song@kernel.org> 
bioset acct is only needed for raid0 and raid5. Therefore, md_run only
allocates it for raid0 and raid5. However, this does not cover
personality takeover, which may cause uninitialized bioset. For example,
the following repro steps:

  mdadm -CR /dev/md0 -l1 -n2 /dev/loop0 /dev/loop1
  mdadm --wait /dev/md0
  mkfs.xfs /dev/md0
  mdadm /dev/md0 --grow -l5
  mount /dev/md0 /mnt

causes panic like:

[  225.933939] BUG: kernel NULL pointer dereference, address: 0000000000000000
[  225.934903] #PF: supervisor instruction fetch in kernel mode
[  225.935639] #PF: error_code(0x0010) - not-present page
[  225.936361] PGD 0 P4D 0
[  225.936677] Oops: 0010 [#1] PREEMPT SMP DEBUG_PAGEALLOC KASAN PTI
[  225.937525] CPU: 27 PID: 1133 Comm: mount Not tainted 5.16.0-rc3+ #706
[  225.938416] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-2.module_el8.4.0+547+a85d02ba 04/01/2014
[  225.939922] RIP: 0010:0x0
[  225.940289] Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
[  225.941196] RSP: 0018:ffff88815897eff0 EFLAGS: 00010246
[  225.941897] RAX: 0000000000000000 RBX: 0000000000092800 RCX: ffffffff81370a39
[  225.942813] RDX: dffffc0000000000 RSI: 0000000000000000 RDI: 0000000000092800
[  225.943772] RBP: 1ffff1102b12fe04 R08: fffffbfff0b43c01 R09: fffffbfff0b43c01
[  225.944807] R10: ffffffff85a1e007 R11: fffffbfff0b43c00 R12: ffff88810eaaaf58
[  225.945757] R13: 0000000000000000 R14: ffff88810eaaafb8 R15: ffff88815897f040
[  225.946709] FS:  00007ff3f2505080(0000) GS:ffff888fb5e00000(0000) knlGS:0000000000000000
[  225.947814] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  225.948556] CR2: ffffffffffffffd6 CR3: 000000015aa5a006 CR4: 0000000000370ee0
[  225.949537] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  225.950455] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  225.951414] Call Trace:
[  225.951787]  <TASK>
[  225.952120]  mempool_alloc+0xe5/0x250
[  225.952625]  ? mempool_resize+0x370/0x370
[  225.953187]  ? rcu_read_lock_sched_held+0xa1/0xd0
[  225.953862]  ? rcu_read_lock_bh_held+0xb0/0xb0
[  225.954464]  ? sched_clock_cpu+0x15/0x120
[  225.955019]  ? find_held_lock+0xac/0xd0
[  225.955564]  bio_alloc_bioset+0x1ed/0x2a0
[  225.956080]  ? lock_downgrade+0x3a0/0x3a0
[  225.956644]  ? bvec_alloc+0xc0/0xc0
[  225.957135]  bio_clone_fast+0x19/0x80
[  225.957651]  raid5_make_request+0x1370/0x1b70
[  225.958286]  ? sched_clock_cpu+0x15/0x120
[  225.958797]  ? __lock_acquire+0x8b2/0x3510
[  225.959339]  ? raid5_get_active_stripe+0xce0/0xce0
[  225.959986]  ? lock_is_held_type+0xd8/0x130
[  225.960528]  ? rcu_read_lock_sched_held+0xa1/0xd0
[  225.961135]  ? rcu_read_lock_bh_held+0xb0/0xb0
[  225.961703]  ? sched_clock_cpu+0x15/0x120
[  225.962232]  ? lock_release+0x27a/0x6c0
[  225.962746]  ? do_wait_intr_irq+0x130/0x130
[  225.963302]  ? lock_downgrade+0x3a0/0x3a0
[  225.963815]  ? lock_release+0x6c0/0x6c0
[  225.964348]  md_handle_request+0x342/0x530
[  225.964888]  ? set_in_sync+0x170/0x170
[  225.965397]  ? blk_queue_split+0x133/0x150
[  225.965988]  ? __blk_queue_split+0x8b0/0x8b0
[  225.966524]  ? submit_bio_checks+0x3b2/0x9d0
[  225.967069]  md_submit_bio+0x127/0x1c0
[...]

Fix this by moving alloc/free of acct bioset to pers->run and pers->free.

While we are on this, properly handle md_integrity_register() error in
raid0_run().

Fixes: daee2024715d (md: check level before create and exit io_acct_set)
Cc: stable@vger.kernel.org
Acked-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Signed-off-by: Xiao Ni <xni@redhat.com>
Signed-off-by: Song Liu <song@kernel.org>