diff options
| author | Yu Kuai <yukuai3@huawei.com> | 2023-08-25 05:55:32 +0300 |
|---|---|---|
| committer | Song Liu <song@kernel.org> | 2023-09-08 23:16:40 +0300 |
| commit | 99892147f028d711f9d40fefad4f33632593864c (patch) | |
| tree | db3d8ca37ec0ea6482f8ab31132c154ae43c4501 /drivers/md | |
| parent | 7deac114be5fb25a4e865212ed0feaf5f85f2a28 (diff) | |
| download | linux-99892147f028d711f9d40fefad4f33632593864c.tar.xz | |
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 'drivers/md')
| -rw-r--r-- | drivers/md/md.c | 15 | ||||
| -rw-r--r-- | drivers/md/md.h | 3 |
2 files changed, 15 insertions, 3 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c index 590aee057aca..73758b754127 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -2452,7 +2452,8 @@ static void export_rdev(struct md_rdev *rdev, struct mddev *mddev) if (test_bit(AutoDetected, &rdev->flags)) md_autodetect_dev(rdev->bdev->bd_dev); #endif - blkdev_put(rdev->bdev, mddev->external ? &claim_rdev : rdev); + blkdev_put(rdev->bdev, + test_bit(Holder, &rdev->flags) ? rdev : &claim_rdev); rdev->bdev = NULL; kobject_put(&rdev->kobj); } @@ -3632,6 +3633,7 @@ EXPORT_SYMBOL_GPL(md_rdev_init); static struct md_rdev *md_import_device(dev_t newdev, int super_format, int super_minor) { struct md_rdev *rdev; + struct md_rdev *holder; sector_t size; int err; @@ -3646,8 +3648,15 @@ static struct md_rdev *md_import_device(dev_t newdev, int super_format, int supe if (err) goto out_clear_rdev; + if (super_format == -2) { + holder = &claim_rdev; + } else { + holder = rdev; + set_bit(Holder, &rdev->flags); + } + rdev->bdev = blkdev_get_by_dev(newdev, BLK_OPEN_READ | BLK_OPEN_WRITE, - super_format == -2 ? &claim_rdev : rdev, NULL); + holder, NULL); if (IS_ERR(rdev->bdev)) { pr_warn("md: could not open device unknown-block(%u,%u).\n", MAJOR(newdev), MINOR(newdev)); @@ -3684,7 +3693,7 @@ static struct md_rdev *md_import_device(dev_t newdev, int super_format, int supe return rdev; out_blkdev_put: - blkdev_put(rdev->bdev, super_format == -2 ? &claim_rdev : rdev); + blkdev_put(rdev->bdev, holder); out_clear_rdev: md_rdev_clear(rdev); out_free_rdev: 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, |