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code made very faster #562
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Hi @IMPZERO! Thanks for your contribution to the Linux kernel! Linux kernel development happens on mailing lists, rather than on GitHub - this GitHub repository is a read-only mirror that isn't used for accepting contributions. So that your change can become part of Linux, please email it to us as a patch. Sending patches isn't quite as simple as sending a pull request, but fortunately it is a well documented process. Here's what to do:
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i like |
these trolls are getting better by each day. |
okay then |
i approve |
Another "put code on one line for optimization pr"? |
This guy is going places. |
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I think there are too much content in the README file. Fix that.
Hello frands chai pilo ;-) |
LOL. |
Oh gawd that face... O-O |
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👍 LGTM
I actually believed this at first until I saw this guy's profile... I should stay off XDA-developers for a bit. |
yawn Can we close this garbage now? |
Very well done sir! I really like your coding skills. |
This can be merged after the conflict with |
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I approve this PR now, not tomorrow.
We have a long standing problem with reversed keys that's detected by btrfs_set_item_key_safe. This is hard to reproduce so we'd like to capture more information for later analysis. Let's dump the leaf content before triggering BUG_ON() so that we can have some clue on what's going wrong. The output of tree locks should help us to debug such problem. Sample stacktrace: generic/522 [00:07:05] [26946.113381] run fstests generic/522 at 2019-04-16 00:07:05 [27161.474720] kernel BUG at fs/btrfs/ctree.c:3192! [27161.475923] invalid opcode: 0000 [#1] PREEMPT SMP [27161.477167] CPU: 0 PID: 15676 Comm: fsx Tainted: G W 5.1.0-rc5-default+ torvalds#562 [27161.478932] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c89-prebuilt.qemu.org 04/01/2014 [27161.481099] RIP: 0010:btrfs_set_item_key_safe+0x146/0x1c0 [btrfs] [27161.485369] RSP: 0018:ffffb087499e39b0 EFLAGS: 00010286 [27161.486464] RAX: 00000000ffffffff RBX: ffff941534d80e70 RCX: 0000000000024000 [27161.487929] RDX: 0000000000013039 RSI: ffffb087499e3aa5 RDI: ffffb087499e39c7 [27161.489289] RBP: 000000000000000e R08: ffff9414e0f49008 R09: 0000000000001000 [27161.490807] R10: 0000000000000000 R11: 0000000000000003 R12: ffff9414e0f48e70 [27161.492305] R13: ffffb087499e3aa5 R14: 0000000000000000 R15: 0000000000071000 [27161.493845] FS: 00007f8ea58d0b80(0000) GS:ffff94153d400000(0000) knlGS:0000000000000000 [27161.495608] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [27161.496717] CR2: 00007f8ea57a9000 CR3: 0000000016a33000 CR4: 00000000000006f0 [27161.498100] Call Trace: [27161.498771] __btrfs_drop_extents+0x6ec/0xdf0 [btrfs] [27161.499872] btrfs_log_changed_extents.isra.26+0x3a2/0x9e0 [btrfs] [27161.501114] btrfs_log_inode+0x7ff/0xdc0 [btrfs] [27161.502114] ? __mutex_unlock_slowpath+0x4b/0x2b0 [27161.503172] btrfs_log_inode_parent+0x237/0x9c0 [btrfs] [27161.504348] btrfs_log_dentry_safe+0x4a/0x70 [btrfs] [27161.505374] btrfs_sync_file+0x1b7/0x480 [btrfs] [27161.506371] __x64_sys_msync+0x180/0x210 [27161.507208] do_syscall_64+0x54/0x180 [27161.507932] entry_SYSCALL_64_after_hwframe+0x49/0xbe [27161.508839] RIP: 0033:0x7f8ea5aa9c61 [27161.512616] RSP: 002b:00007ffea2a06498 EFLAGS: 00000246 ORIG_RAX: 000000000000001a [27161.514161] RAX: ffffffffffffffda RBX: 000000000002a938 RCX: 00007f8ea5aa9c61 [27161.515376] RDX: 0000000000000004 RSI: 000000000001c9b2 RDI: 00007f8ea578d000 [27161.516572] RBP: 000000000001c07a R08: fffffffffffffff8 R09: 000000000002a000 [27161.517883] R10: 00007f8ea57a99b2 R11: 0000000000000246 R12: 0000000000000938 [27161.519080] R13: 00007f8ea578d000 R14: 000000000001c9b2 R15: 0000000000000000 [27161.520281] Modules linked in: btrfs libcrc32c xor zstd_decompress zstd_compress xxhash raid6_pq loop [last unloaded: scsi_debug] [27161.522272] ---[ end trace d5afec7ccac6a252 ]--- [27161.523111] RIP: 0010:btrfs_set_item_key_safe+0x146/0x1c0 [btrfs] [27161.527253] RSP: 0018:ffffb087499e39b0 EFLAGS: 00010286 [27161.528192] RAX: 00000000ffffffff RBX: ffff941534d80e70 RCX: 0000000000024000 [27161.529392] RDX: 0000000000013039 RSI: ffffb087499e3aa5 RDI: ffffb087499e39c7 [27161.530607] RBP: 000000000000000e R08: ffff9414e0f49008 R09: 0000000000001000 [27161.531802] R10: 0000000000000000 R11: 0000000000000003 R12: ffff9414e0f48e70 [27161.533018] R13: ffffb087499e3aa5 R14: 0000000000000000 R15: 0000000000071000 [27161.534405] FS: 00007f8ea58d0b80(0000) GS:ffff94153d400000(0000) knlGS:0000000000000000 [27161.536048] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [27161.537210] CR2: 00007f8ea57a9000 CR3: 0000000016a33000 CR4: 00000000000006f0 Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
Fix checkpatch warnings: WARNING: Prefer 'unsigned int' to bare use of 'unsigned' torvalds#562: FILE: drivers/tty/serial/uartlite.c:562: + unsigned retries = 1000000; WARNING: Prefer 'unsigned int' to bare use of 'unsigned' torvalds#574: FILE: drivers/tty/serial/uartlite.c:574: + const char *s, unsigned n) Signed-off-by: Enrico Weigelt <info@metux.net>
We have a long standing problem with reversed keys that's detected by btrfs_set_item_key_safe. This is hard to reproduce so we'd like to capture more information for later analysis. Let's dump the leaf content before triggering BUG_ON() so that we can have some clue on what's going wrong. The output of tree locks should help us to debug such problem. Sample stacktrace: generic/522 [00:07:05] [26946.113381] run fstests generic/522 at 2019-04-16 00:07:05 [27161.474720] kernel BUG at fs/btrfs/ctree.c:3192! [27161.475923] invalid opcode: 0000 [#1] PREEMPT SMP [27161.477167] CPU: 0 PID: 15676 Comm: fsx Tainted: G W 5.1.0-rc5-default+ torvalds#562 [27161.478932] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c89-prebuilt.qemu.org 04/01/2014 [27161.481099] RIP: 0010:btrfs_set_item_key_safe+0x146/0x1c0 [btrfs] [27161.485369] RSP: 0018:ffffb087499e39b0 EFLAGS: 00010286 [27161.486464] RAX: 00000000ffffffff RBX: ffff941534d80e70 RCX: 0000000000024000 [27161.487929] RDX: 0000000000013039 RSI: ffffb087499e3aa5 RDI: ffffb087499e39c7 [27161.489289] RBP: 000000000000000e R08: ffff9414e0f49008 R09: 0000000000001000 [27161.490807] R10: 0000000000000000 R11: 0000000000000003 R12: ffff9414e0f48e70 [27161.492305] R13: ffffb087499e3aa5 R14: 0000000000000000 R15: 0000000000071000 [27161.493845] FS: 00007f8ea58d0b80(0000) GS:ffff94153d400000(0000) knlGS:0000000000000000 [27161.495608] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [27161.496717] CR2: 00007f8ea57a9000 CR3: 0000000016a33000 CR4: 00000000000006f0 [27161.498100] Call Trace: [27161.498771] __btrfs_drop_extents+0x6ec/0xdf0 [btrfs] [27161.499872] btrfs_log_changed_extents.isra.26+0x3a2/0x9e0 [btrfs] [27161.501114] btrfs_log_inode+0x7ff/0xdc0 [btrfs] [27161.502114] ? __mutex_unlock_slowpath+0x4b/0x2b0 [27161.503172] btrfs_log_inode_parent+0x237/0x9c0 [btrfs] [27161.504348] btrfs_log_dentry_safe+0x4a/0x70 [btrfs] [27161.505374] btrfs_sync_file+0x1b7/0x480 [btrfs] [27161.506371] __x64_sys_msync+0x180/0x210 [27161.507208] do_syscall_64+0x54/0x180 [27161.507932] entry_SYSCALL_64_after_hwframe+0x49/0xbe [27161.508839] RIP: 0033:0x7f8ea5aa9c61 [27161.512616] RSP: 002b:00007ffea2a06498 EFLAGS: 00000246 ORIG_RAX: 000000000000001a [27161.514161] RAX: ffffffffffffffda RBX: 000000000002a938 RCX: 00007f8ea5aa9c61 [27161.515376] RDX: 0000000000000004 RSI: 000000000001c9b2 RDI: 00007f8ea578d000 [27161.516572] RBP: 000000000001c07a R08: fffffffffffffff8 R09: 000000000002a000 [27161.517883] R10: 00007f8ea57a99b2 R11: 0000000000000246 R12: 0000000000000938 [27161.519080] R13: 00007f8ea578d000 R14: 000000000001c9b2 R15: 0000000000000000 [27161.520281] Modules linked in: btrfs libcrc32c xor zstd_decompress zstd_compress xxhash raid6_pq loop [last unloaded: scsi_debug] [27161.522272] ---[ end trace d5afec7ccac6a252 ]--- [27161.523111] RIP: 0010:btrfs_set_item_key_safe+0x146/0x1c0 [btrfs] [27161.527253] RSP: 0018:ffffb087499e39b0 EFLAGS: 00010286 [27161.528192] RAX: 00000000ffffffff RBX: ffff941534d80e70 RCX: 0000000000024000 [27161.529392] RDX: 0000000000013039 RSI: ffffb087499e3aa5 RDI: ffffb087499e39c7 [27161.530607] RBP: 000000000000000e R08: ffff9414e0f49008 R09: 0000000000001000 [27161.531802] R10: 0000000000000000 R11: 0000000000000003 R12: ffff9414e0f48e70 [27161.533018] R13: ffffb087499e3aa5 R14: 0000000000000000 R15: 0000000000071000 [27161.534405] FS: 00007f8ea58d0b80(0000) GS:ffff94153d400000(0000) knlGS:0000000000000000 [27161.536048] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [27161.537210] CR2: 00007f8ea57a9000 CR3: 0000000016a33000 CR4: 00000000000006f0 Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
Fix checkpatch warnings: WARNING: Prefer 'unsigned int' to bare use of 'unsigned' torvalds#562: FILE: drivers/tty/serial/uartlite.c:562: + unsigned retries = 1000000; WARNING: Prefer 'unsigned int' to bare use of 'unsigned' torvalds#574: FILE: drivers/tty/serial/uartlite.c:574: + const char *s, unsigned n) Signed-off-by: Enrico Weigelt <info@metux.net> Acked-by: Peter Korsgaard <peter@korsgaard.com>
Fix checkpatch warnings: WARNING: Prefer 'unsigned int' to bare use of 'unsigned' torvalds#562: FILE: drivers/tty/serial/uartlite.c:562: + unsigned retries = 1000000; WARNING: Prefer 'unsigned int' to bare use of 'unsigned' torvalds#574: FILE: drivers/tty/serial/uartlite.c:574: + const char *s, unsigned n) Signed-off-by: Enrico Weigelt <info@metux.net> Acked-by: Peter Korsgaard <peter@korsgaard.com>
Fix checkpatch warnings: WARNING: Prefer 'unsigned int' to bare use of 'unsigned' torvalds#562: FILE: drivers/tty/serial/uartlite.c:562: + unsigned retries = 1000000; WARNING: Prefer 'unsigned int' to bare use of 'unsigned' torvalds#574: FILE: drivers/tty/serial/uartlite.c:574: + const char *s, unsigned n) Signed-off-by: Enrico Weigelt <info@metux.net> Acked-by: Peter Korsgaard <peter@korsgaard.com>
Fix checkpatch warnings: WARNING: Prefer 'unsigned int' to bare use of 'unsigned' torvalds#562: FILE: drivers/tty/serial/uartlite.c:562: + unsigned retries = 1000000; WARNING: Prefer 'unsigned int' to bare use of 'unsigned' torvalds#574: FILE: drivers/tty/serial/uartlite.c:574: + const char *s, unsigned n) Signed-off-by: Enrico Weigelt <info@metux.net>
Fix checkpatch warnings: WARNING: Prefer 'unsigned int' to bare use of 'unsigned' torvalds#562: FILE: drivers/tty/serial/uartlite.c:562: + unsigned retries = 1000000; WARNING: Prefer 'unsigned int' to bare use of 'unsigned' torvalds#574: FILE: drivers/tty/serial/uartlite.c:574: + const char *s, unsigned n) Signed-off-by: Enrico Weigelt <info@metux.net>
Fix checkpatch warnings: WARNING: Prefer 'unsigned int' to bare use of 'unsigned' torvalds#562: FILE: drivers/tty/serial/uartlite.c:562: + unsigned retries = 1000000; WARNING: Prefer 'unsigned int' to bare use of 'unsigned' torvalds#574: FILE: drivers/tty/serial/uartlite.c:574: + const char *s, unsigned n) Signed-off-by: Enrico Weigelt <info@metux.net>
Fix checkpatch warnings: WARNING: Prefer 'unsigned int' to bare use of 'unsigned' torvalds#562: FILE: drivers/tty/serial/uartlite.c:562: + unsigned retries = 1000000; WARNING: Prefer 'unsigned int' to bare use of 'unsigned' torvalds#574: FILE: drivers/tty/serial/uartlite.c:574: + const char *s, unsigned n) Signed-off-by: Enrico Weigelt <info@metux.net>
Fix checkpatch warnings: WARNING: Prefer 'unsigned int' to bare use of 'unsigned' torvalds#562: FILE: drivers/tty/serial/uartlite.c:562: + unsigned retries = 1000000; WARNING: Prefer 'unsigned int' to bare use of 'unsigned' torvalds#574: FILE: drivers/tty/serial/uartlite.c:574: + const char *s, unsigned n) Signed-off-by: Enrico Weigelt <info@metux.net>
Fix checkpatch warnings: WARNING: Prefer 'unsigned int' to bare use of 'unsigned' torvalds#562: FILE: drivers/tty/serial/uartlite.c:562: + unsigned retries = 1000000; WARNING: Prefer 'unsigned int' to bare use of 'unsigned' torvalds#574: FILE: drivers/tty/serial/uartlite.c:574: + const char *s, unsigned n) Signed-off-by: Enrico Weigelt <info@metux.net>
Fix checkpatch warnings: WARNING: Prefer 'unsigned int' to bare use of 'unsigned' torvalds#562: FILE: drivers/tty/serial/uartlite.c:562: + unsigned retries = 1000000; WARNING: Prefer 'unsigned int' to bare use of 'unsigned' torvalds#574: FILE: drivers/tty/serial/uartlite.c:574: + const char *s, unsigned n) Signed-off-by: Enrico Weigelt <info@metux.net>
Fix checkpatch warnings: WARNING: Prefer 'unsigned int' to bare use of 'unsigned' torvalds#562: FILE: drivers/tty/serial/uartlite.c:562: + unsigned retries = 1000000; WARNING: Prefer 'unsigned int' to bare use of 'unsigned' torvalds#574: FILE: drivers/tty/serial/uartlite.c:574: + const char *s, unsigned n) Signed-off-by: Enrico Weigelt <info@metux.net>
Fix checkpatch warnings: WARNING: Prefer 'unsigned int' to bare use of 'unsigned' torvalds#562: FILE: drivers/tty/serial/uartlite.c:562: + unsigned retries = 1000000; WARNING: Prefer 'unsigned int' to bare use of 'unsigned' torvalds#574: FILE: drivers/tty/serial/uartlite.c:574: + const char *s, unsigned n) Signed-off-by: Enrico Weigelt <info@metux.net>
`Makefile` cleanups
Except for initial reference, mddev->kobject is referenced by rdev->kobject, and if the last rdev is freed, there is no guarantee that mddev is still valid. Hence mddev should not be used anymore after export_rdev(). This problem can be triggered by following test for mdadm at very low rate: New file: mdadm/tests/23rdev-lifetime devname=${dev0##*/} devt=`cat /sys/block/$devname/dev` pid="" runtime=2 clean_up_test() { pill -9 $pid echo clear > /sys/block/md0/md/array_state } trap 'clean_up_test' EXIT add_by_sysfs() { while true; do echo $devt > /sys/block/md0/md/new_dev done } remove_by_sysfs(){ while true; do echo remove > /sys/block/md0/md/dev-${devname}/state done } echo md0 > /sys/module/md_mod/parameters/new_array || die "create md0 failed" add_by_sysfs & pid="$pid $!" remove_by_sysfs & pid="$pid $!" sleep $runtime exit 0 Test cmd: ./test --save-logs --logdir=/tmp/ --keep-going --dev=loop --tests=23rdev-lifetime Test result: general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6bcb: 0000 [#4] PREEMPT SMP CPU: 0 PID: 1292 Comm: test Tainted: G D W 6.5.0-rc2-00121-g01e55c376936 torvalds#562 RIP: 0010:md_wakeup_thread+0x9e/0x320 [md_mod] Call Trace: <TASK> mddev_unlock+0x1b6/0x310 [md_mod] rdev_attr_store+0xec/0x190 [md_mod] sysfs_kf_write+0x52/0x70 kernfs_fop_write_iter+0x19a/0x2a0 vfs_write+0x3b5/0x770 ksys_write+0x74/0x150 __x64_sys_write+0x22/0x30 do_syscall_64+0x40/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd Fix this problem by don't dereference mddev after export_rdev(). Fixes: 3ce94ce ("md: fix duplicate filename for rdev") Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Except for initial reference, mddev->kobject is referenced by rdev->kobject, and if the last rdev is freed, there is no guarantee that mddev is still valid. Hence mddev should not be used anymore after export_rdev(). This problem can be triggered by following test for mdadm at very low rate: New file: mdadm/tests/23rdev-lifetime devname=${dev0##*/} devt=`cat /sys/block/$devname/dev` pid="" runtime=2 clean_up_test() { pill -9 $pid echo clear > /sys/block/md0/md/array_state } trap 'clean_up_test' EXIT add_by_sysfs() { while true; do echo $devt > /sys/block/md0/md/new_dev done } remove_by_sysfs(){ while true; do echo remove > /sys/block/md0/md/dev-${devname}/state done } echo md0 > /sys/module/md_mod/parameters/new_array || die "create md0 failed" add_by_sysfs & pid="$pid $!" remove_by_sysfs & pid="$pid $!" sleep $runtime exit 0 Test cmd: ./test --save-logs --logdir=/tmp/ --keep-going --dev=loop --tests=23rdev-lifetime Test result: general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6bcb: 0000 [#4] PREEMPT SMP CPU: 0 PID: 1292 Comm: test Tainted: G D W 6.5.0-rc2-00121-g01e55c376936 torvalds#562 RIP: 0010:md_wakeup_thread+0x9e/0x320 [md_mod] Call Trace: <TASK> mddev_unlock+0x1b6/0x310 [md_mod] rdev_attr_store+0xec/0x190 [md_mod] sysfs_kf_write+0x52/0x70 kernfs_fop_write_iter+0x19a/0x2a0 vfs_write+0x3b5/0x770 ksys_write+0x74/0x150 __x64_sys_write+0x22/0x30 do_syscall_64+0x40/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd Fix this problem by don't dereference mddev after export_rdev(). Fixes: 3ce94ce ("md: fix duplicate filename for rdev") Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230825025532.1523008-2-yukuai1@huaweicloud.com
Except for initial reference, mddev->kobject is referenced by rdev->kobject, and if the last rdev is freed, there is no guarantee that mddev is still valid. Hence mddev should not be used anymore after export_rdev(). This problem can be triggered by following test for mdadm at very low rate: New file: mdadm/tests/23rdev-lifetime devname=${dev0##*/} devt=`cat /sys/block/$devname/dev` pid="" runtime=2 clean_up_test() { pill -9 $pid echo clear > /sys/block/md0/md/array_state } trap 'clean_up_test' EXIT add_by_sysfs() { while true; do echo $devt > /sys/block/md0/md/new_dev done } remove_by_sysfs(){ while true; do echo remove > /sys/block/md0/md/dev-${devname}/state done } echo md0 > /sys/module/md_mod/parameters/new_array || die "create md0 failed" add_by_sysfs & pid="$pid $!" remove_by_sysfs & pid="$pid $!" sleep $runtime exit 0 Test cmd: ./test --save-logs --logdir=/tmp/ --keep-going --dev=loop --tests=23rdev-lifetime Test result: general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6bcb: 0000 [#4] PREEMPT SMP CPU: 0 PID: 1292 Comm: test Tainted: G D W 6.5.0-rc2-00121-g01e55c376936 #562 RIP: 0010:md_wakeup_thread+0x9e/0x320 [md_mod] Call Trace: <TASK> mddev_unlock+0x1b6/0x310 [md_mod] rdev_attr_store+0xec/0x190 [md_mod] sysfs_kf_write+0x52/0x70 kernfs_fop_write_iter+0x19a/0x2a0 vfs_write+0x3b5/0x770 ksys_write+0x74/0x150 __x64_sys_write+0x22/0x30 do_syscall_64+0x40/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd Fix this problem by don't dereference mddev after export_rdev(). Fixes: 3ce94ce ("md: fix duplicate filename for rdev") Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230825025532.1523008-2-yukuai1@huaweicloud.com
[ Upstream commit 7deac11 ] Except for initial reference, mddev->kobject is referenced by rdev->kobject, and if the last rdev is freed, there is no guarantee that mddev is still valid. Hence mddev should not be used anymore after export_rdev(). This problem can be triggered by following test for mdadm at very low rate: New file: mdadm/tests/23rdev-lifetime devname=${dev0##*/} devt=`cat /sys/block/$devname/dev` pid="" runtime=2 clean_up_test() { pill -9 $pid echo clear > /sys/block/md0/md/array_state } trap 'clean_up_test' EXIT add_by_sysfs() { while true; do echo $devt > /sys/block/md0/md/new_dev done } remove_by_sysfs(){ while true; do echo remove > /sys/block/md0/md/dev-${devname}/state done } echo md0 > /sys/module/md_mod/parameters/new_array || die "create md0 failed" add_by_sysfs & pid="$pid $!" remove_by_sysfs & pid="$pid $!" sleep $runtime exit 0 Test cmd: ./test --save-logs --logdir=/tmp/ --keep-going --dev=loop --tests=23rdev-lifetime Test result: general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6bcb: 0000 [#4] PREEMPT SMP CPU: 0 PID: 1292 Comm: test Tainted: G D W 6.5.0-rc2-00121-g01e55c376936 torvalds#562 RIP: 0010:md_wakeup_thread+0x9e/0x320 [md_mod] Call Trace: <TASK> mddev_unlock+0x1b6/0x310 [md_mod] rdev_attr_store+0xec/0x190 [md_mod] sysfs_kf_write+0x52/0x70 kernfs_fop_write_iter+0x19a/0x2a0 vfs_write+0x3b5/0x770 ksys_write+0x74/0x150 __x64_sys_write+0x22/0x30 do_syscall_64+0x40/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd Fix this problem by don't dereference mddev after export_rdev(). Fixes: 3ce94ce ("md: fix duplicate filename for rdev") Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230825025532.1523008-2-yukuai1@huaweicloud.com Signed-off-by: Sasha Levin <sashal@kernel.org>
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