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authorYu Kuai <yukuai3@huawei.com>2023-08-25 04:55:32 +0200
committerSong Liu <song@kernel.org>2023-09-08 22:16:40 +0200
commit99892147f028d711f9d40fefad4f33632593864c (patch)
treedb3d8ca37ec0ea6482f8ab31132c154ae43c4501 /drivers/md/md.h
parentmd: don't dereference mddev after export_rdev() (diff)
downloadlinux-99892147f028d711f9d40fefad4f33632593864c.tar.xz
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md: fix warning for holder mismatch from export_rdev()
Commit a1d767191096 ("md: use mddev->external to select holder in export_rdev()") fix the problem that 'claim_rdev' is used for blkdev_get_by_dev() while 'rdev' is used for blkdev_put(). However, if mddev->external is changed from 0 to 1, then 'rdev' is used for blkdev_get_by_dev() while 'claim_rdev' is used for blkdev_put(). And this problem can be reporduced reliably by following: 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: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 960 at block/bdev.c:618 blkdev_put+0x27c/0x330 Modules linked in: multipath md_mod loop CPU: 0 PID: 960 Comm: test Not tainted 6.5.0-rc2-00121-g01e55c376936-dirty #50 RIP: 0010:blkdev_put+0x27c/0x330 Call Trace: <TASK> export_rdev.isra.23+0x50/0xa0 [md_mod] mddev_unlock+0x19d/0x300 [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 the problem by recording if 'rdev' is used as holder. Fixes: a1d767191096 ("md: use mddev->external to select holder in export_rdev()") Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230825025532.1523008-3-yukuai1@huaweicloud.com
Diffstat (limited to '')
-rw-r--r--drivers/md/md.h3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/md/md.h b/drivers/md/md.h
index 9bcb77bca963..7c9c13abd7ca 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -211,6 +211,9 @@ enum flag_bits {
* check if there is collision between raid1
* serial bios.
*/
+ Holder, /* rdev is used as holder while opening
+ * underlying disk exclusively.
+ */
};
static inline int is_badblock(struct md_rdev *rdev, sector_t s, int sectors,