* [PATCH -next] block: don't allow a disk link holder to its ancestor
@ 2023-04-25 7:55 Li Lingfeng
2023-04-25 8:13 ` Chaitanya Kulkarni
2023-10-08 1:14 ` Li Lingfeng
0 siblings, 2 replies; 4+ messages in thread
From: Li Lingfeng @ 2023-04-25 7:55 UTC (permalink / raw)
To: hch, axboe
Cc: linux-block, linux-kernel, yukuai1, houtao1, yi.zhang, lilingfeng
From: Li Lingfeng <lilingfeng3@huawei.com>
Previously commit 077a4033541f ("block: don't allow a disk link holder
to itself") prevent user from reloading dm with itself. However, user
can reload dm with its ancestor which will trigger dead loop and result
in oom.
Test procedures:
1) dmsetup create test --table "0 20971520 linear /dev/sdd 0"
2) dmsetup create test1 --table "0 20971520 linear /dev/sdd 20971520"
3) dmsetup suspend test
4) dmsetup reload test --table "0 2048 linear /dev/mapper/test1 0"
5) dmsetup resume test
6) dmsetup suspend test1
7) dmsetup reload test1 --table "0 2048 linear /dev/mapper/test 0"
8) dmsetup resume test1
Dead loop:
[ 229.681231] Call Trace:
[ 229.681232] dm_dax_supported+0x5b/0xa0
[ 229.681233] dax_supported+0x28/0x50
[ 229.681234] device_not_dax_capable+0x45/0x70
[ 229.681235] ? realloc_argv+0xa0/0xa0
[ 229.681236] linear_iterate_devices+0x25/0x30
[ 229.681237] dm_table_supports_dax+0x42/0xd0
[ 229.681238] dm_dax_supported+0x5b/0xa0
[ 229.681238] dax_supported+0x28/0x50
[ 229.681239] device_not_dax_capable+0x45/0x70
......(a lot of same lines)
[ 229.681423] ? realloc_argv+0xa0/0xa0
[ 229.681424] linear_iterate_devices+0x25/0x30
[ 229.681425] dm_table_supports_dax+0x42/0xd0
[ 229.681426] dm
[ 229.681428] Lost 437 message(s)!
[ 229.825588] ---[ end trace 0f2a9db839ed5b56 ]---
OOM:
[ 189.270011] Call Trace:
[ 189.270274] <TASK>
[ 189.270511] dump_stack_lvl+0xc1/0x170
[ 189.270899] dump_stack+0x14/0x20
[ 189.271222] dump_header+0x5a/0x710
[ 189.271590] oom_kill_process+0x16b/0x500
[ 189.272018] out_of_memory+0x333/0xad0
[ 189.272453] __alloc_pages_slowpath.constprop.0+0x18b4/0x1c40
[ 189.273130] ? find_held_lock+0x33/0xf0
[ 189.273637] __alloc_pages+0x598/0x660
[ 189.274106] alloc_pages+0x95/0x240
[ 189.274482] folio_alloc+0x1f/0x60
[ 189.274835] filemap_alloc_folio+0x223/0x350
[ 189.275348] __filemap_get_folio+0x21e/0x770
[ 189.275916] filemap_fault+0x72d/0xdc0
[ 189.276454] __do_fault+0x41/0x360
[ 189.276820] do_fault+0x263/0x8f0
[ 189.277175] __handle_mm_fault+0x9af/0x1b20
[ 189.277810] handle_mm_fault+0x128/0x570
[ 189.278243] do_user_addr_fault+0x2af/0xea0
[ 189.278733] exc_page_fault+0x73/0x340
[ 189.279133] asm_exc_page_fault+0x22/0x30
[ 189.279523] RIP: 0033:0x561e82ac67f0
Forbidding a disk to create link to its ancestor can solve the problem.
What's more, limit device depth to prevent recursive overflow.
Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com>
---
block/holder.c | 42 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 42 insertions(+)
diff --git a/block/holder.c b/block/holder.c
index 37d18c13d958..6a8571b7d9c5 100644
--- a/block/holder.c
+++ b/block/holder.c
@@ -2,9 +2,13 @@
#include <linux/blkdev.h>
#include <linux/slab.h>
+#define DEVICE_DEPTH 5
+static DEFINE_MUTEX(slave_bdevs_lock);
+
struct bd_holder_disk {
struct list_head list;
struct kobject *holder_dir;
+ struct gendisk *slave_disk;
int refcnt;
};
@@ -29,6 +33,32 @@ static void del_symlink(struct kobject *from, struct kobject *to)
sysfs_remove_link(from, kobject_name(to));
}
+static struct gendisk *iterate_slave_disk(struct gendisk *disk,
+ struct gendisk *target, int depth)
+{
+ struct bd_holder_disk *holder;
+ struct gendisk *iter_slave;
+
+ if (!depth)
+ return target;
+
+ if (list_empty_careful(&disk->slave_bdevs))
+ return NULL;
+
+ depth--;
+ list_for_each_entry(holder, &disk->slave_bdevs, list) {
+ if (holder->slave_disk == target)
+ return target;
+
+ iter_slave = iterate_slave_disk(holder->slave_disk, target, depth);
+ if (iter_slave)
+ return iter_slave;
+
+ cond_resched();
+ }
+ return NULL;
+}
+
/**
* bd_link_disk_holder - create symlinks between holding disk and slave bdev
* @bdev: the claimed slave bdev
@@ -62,6 +92,13 @@ int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk)
struct bd_holder_disk *holder;
int ret = 0;
+ mutex_lock(&slave_bdevs_lock);
+ if (iterate_slave_disk(bdev->bd_disk, disk, DEVICE_DEPTH)) {
+ mutex_unlock(&slave_bdevs_lock);
+ return -EINVAL;
+ }
+ mutex_unlock(&slave_bdevs_lock);
+
if (WARN_ON_ONCE(!disk->slave_dir))
return -EINVAL;
@@ -81,6 +118,7 @@ int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk)
mutex_unlock(&bdev->bd_disk->open_mutex);
mutex_lock(&disk->open_mutex);
+ mutex_lock(&slave_bdevs_lock);
WARN_ON_ONCE(!bdev->bd_holder);
holder = bd_find_holder_disk(bdev, disk);
@@ -106,8 +144,10 @@ int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk)
ret = add_symlink(bdev->bd_holder_dir, &disk_to_dev(disk)->kobj);
if (ret)
goto out_del_symlink;
+ holder->slave_disk = bdev->bd_disk;
list_add(&holder->list, &disk->slave_bdevs);
+ mutex_unlock(&slave_bdevs_lock);
mutex_unlock(&disk->open_mutex);
return 0;
@@ -141,6 +181,7 @@ void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk)
return;
mutex_lock(&disk->open_mutex);
+ mutex_lock(&slave_bdevs_lock);
holder = bd_find_holder_disk(bdev, disk);
if (!WARN_ON_ONCE(holder == NULL) && !--holder->refcnt) {
del_symlink(disk->slave_dir, bdev_kobj(bdev));
@@ -149,6 +190,7 @@ void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk)
list_del_init(&holder->list);
kfree(holder);
}
+ mutex_unlock(&slave_bdevs_lock);
mutex_unlock(&disk->open_mutex);
}
EXPORT_SYMBOL_GPL(bd_unlink_disk_holder);
--
2.31.1
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH -next] block: don't allow a disk link holder to its ancestor
2023-04-25 7:55 [PATCH -next] block: don't allow a disk link holder to its ancestor Li Lingfeng
@ 2023-04-25 8:13 ` Chaitanya Kulkarni
2023-10-08 1:14 ` Li Lingfeng
1 sibling, 0 replies; 4+ messages in thread
From: Chaitanya Kulkarni @ 2023-04-25 8:13 UTC (permalink / raw)
To: Li Lingfeng
Cc: linux-block, linux-kernel, yukuai1, houtao1, yi.zhang, axboe, hch
Li,
On 4/25/23 00:55, Li Lingfeng wrote:
> From: Li Lingfeng <lilingfeng3@huawei.com>
>
> Previously commit 077a4033541f ("block: don't allow a disk link holder
> to itself") prevent user from reloading dm with itself. However, user
> can reload dm with its ancestor which will trigger dead loop and result
> in oom.
>
> Test procedures:
> 1) dmsetup create test --table "0 20971520 linear /dev/sdd 0"
> 2) dmsetup create test1 --table "0 20971520 linear /dev/sdd 20971520"
> 3) dmsetup suspend test
> 4) dmsetup reload test --table "0 2048 linear /dev/mapper/test1 0"
> 5) dmsetup resume test
> 6) dmsetup suspend test1
> 7) dmsetup reload test1 --table "0 2048 linear /dev/mapper/test 0"
> 8) dmsetup resume test1
>
Can you please add blktest for this one ?
-ck
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH -next] block: don't allow a disk link holder to its ancestor
2023-04-25 7:55 [PATCH -next] block: don't allow a disk link holder to its ancestor Li Lingfeng
2023-04-25 8:13 ` Chaitanya Kulkarni
@ 2023-10-08 1:14 ` Li Lingfeng
2023-11-13 6:08 ` Li Lingfeng
1 sibling, 1 reply; 4+ messages in thread
From: Li Lingfeng @ 2023-10-08 1:14 UTC (permalink / raw)
To: hch, axboe
Cc: linux-block, linux-kernel, yukuai1, houtao1, yi.zhang,
lilingfeng3, yangerkun
Friendly ping ...
Thanks
在 2023/4/25 15:55, Li Lingfeng 写道:
> From: Li Lingfeng <lilingfeng3@huawei.com>
>
> Previously commit 077a4033541f ("block: don't allow a disk link holder
> to itself") prevent user from reloading dm with itself. However, user
> can reload dm with its ancestor which will trigger dead loop and result
> in oom.
>
> Test procedures:
> 1) dmsetup create test --table "0 20971520 linear /dev/sdd 0"
> 2) dmsetup create test1 --table "0 20971520 linear /dev/sdd 20971520"
> 3) dmsetup suspend test
> 4) dmsetup reload test --table "0 2048 linear /dev/mapper/test1 0"
> 5) dmsetup resume test
> 6) dmsetup suspend test1
> 7) dmsetup reload test1 --table "0 2048 linear /dev/mapper/test 0"
> 8) dmsetup resume test1
>
> Dead loop:
> [ 229.681231] Call Trace:
> [ 229.681232] dm_dax_supported+0x5b/0xa0
> [ 229.681233] dax_supported+0x28/0x50
> [ 229.681234] device_not_dax_capable+0x45/0x70
> [ 229.681235] ? realloc_argv+0xa0/0xa0
> [ 229.681236] linear_iterate_devices+0x25/0x30
> [ 229.681237] dm_table_supports_dax+0x42/0xd0
> [ 229.681238] dm_dax_supported+0x5b/0xa0
> [ 229.681238] dax_supported+0x28/0x50
> [ 229.681239] device_not_dax_capable+0x45/0x70
> ......(a lot of same lines)
> [ 229.681423] ? realloc_argv+0xa0/0xa0
> [ 229.681424] linear_iterate_devices+0x25/0x30
> [ 229.681425] dm_table_supports_dax+0x42/0xd0
> [ 229.681426] dm
> [ 229.681428] Lost 437 message(s)!
> [ 229.825588] ---[ end trace 0f2a9db839ed5b56 ]---
>
> OOM:
> [ 189.270011] Call Trace:
> [ 189.270274] <TASK>
> [ 189.270511] dump_stack_lvl+0xc1/0x170
> [ 189.270899] dump_stack+0x14/0x20
> [ 189.271222] dump_header+0x5a/0x710
> [ 189.271590] oom_kill_process+0x16b/0x500
> [ 189.272018] out_of_memory+0x333/0xad0
> [ 189.272453] __alloc_pages_slowpath.constprop.0+0x18b4/0x1c40
> [ 189.273130] ? find_held_lock+0x33/0xf0
> [ 189.273637] __alloc_pages+0x598/0x660
> [ 189.274106] alloc_pages+0x95/0x240
> [ 189.274482] folio_alloc+0x1f/0x60
> [ 189.274835] filemap_alloc_folio+0x223/0x350
> [ 189.275348] __filemap_get_folio+0x21e/0x770
> [ 189.275916] filemap_fault+0x72d/0xdc0
> [ 189.276454] __do_fault+0x41/0x360
> [ 189.276820] do_fault+0x263/0x8f0
> [ 189.277175] __handle_mm_fault+0x9af/0x1b20
> [ 189.277810] handle_mm_fault+0x128/0x570
> [ 189.278243] do_user_addr_fault+0x2af/0xea0
> [ 189.278733] exc_page_fault+0x73/0x340
> [ 189.279133] asm_exc_page_fault+0x22/0x30
> [ 189.279523] RIP: 0033:0x561e82ac67f0
>
> Forbidding a disk to create link to its ancestor can solve the problem.
> What's more, limit device depth to prevent recursive overflow.
>
> Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com>
> ---
> block/holder.c | 42 ++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 42 insertions(+)
>
> diff --git a/block/holder.c b/block/holder.c
> index 37d18c13d958..6a8571b7d9c5 100644
> --- a/block/holder.c
> +++ b/block/holder.c
> @@ -2,9 +2,13 @@
> #include <linux/blkdev.h>
> #include <linux/slab.h>
>
> +#define DEVICE_DEPTH 5
> +static DEFINE_MUTEX(slave_bdevs_lock);
> +
> struct bd_holder_disk {
> struct list_head list;
> struct kobject *holder_dir;
> + struct gendisk *slave_disk;
> int refcnt;
> };
>
> @@ -29,6 +33,32 @@ static void del_symlink(struct kobject *from, struct kobject *to)
> sysfs_remove_link(from, kobject_name(to));
> }
>
> +static struct gendisk *iterate_slave_disk(struct gendisk *disk,
> + struct gendisk *target, int depth)
> +{
> + struct bd_holder_disk *holder;
> + struct gendisk *iter_slave;
> +
> + if (!depth)
> + return target;
> +
> + if (list_empty_careful(&disk->slave_bdevs))
> + return NULL;
> +
> + depth--;
> + list_for_each_entry(holder, &disk->slave_bdevs, list) {
> + if (holder->slave_disk == target)
> + return target;
> +
> + iter_slave = iterate_slave_disk(holder->slave_disk, target, depth);
> + if (iter_slave)
> + return iter_slave;
> +
> + cond_resched();
> + }
> + return NULL;
> +}
> +
> /**
> * bd_link_disk_holder - create symlinks between holding disk and slave bdev
> * @bdev: the claimed slave bdev
> @@ -62,6 +92,13 @@ int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk)
> struct bd_holder_disk *holder;
> int ret = 0;
>
> + mutex_lock(&slave_bdevs_lock);
> + if (iterate_slave_disk(bdev->bd_disk, disk, DEVICE_DEPTH)) {
> + mutex_unlock(&slave_bdevs_lock);
> + return -EINVAL;
> + }
> + mutex_unlock(&slave_bdevs_lock);
> +
> if (WARN_ON_ONCE(!disk->slave_dir))
> return -EINVAL;
>
> @@ -81,6 +118,7 @@ int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk)
> mutex_unlock(&bdev->bd_disk->open_mutex);
>
> mutex_lock(&disk->open_mutex);
> + mutex_lock(&slave_bdevs_lock);
> WARN_ON_ONCE(!bdev->bd_holder);
>
> holder = bd_find_holder_disk(bdev, disk);
> @@ -106,8 +144,10 @@ int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk)
> ret = add_symlink(bdev->bd_holder_dir, &disk_to_dev(disk)->kobj);
> if (ret)
> goto out_del_symlink;
> + holder->slave_disk = bdev->bd_disk;
> list_add(&holder->list, &disk->slave_bdevs);
>
> + mutex_unlock(&slave_bdevs_lock);
> mutex_unlock(&disk->open_mutex);
> return 0;
>
> @@ -141,6 +181,7 @@ void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk)
> return;
>
> mutex_lock(&disk->open_mutex);
> + mutex_lock(&slave_bdevs_lock);
> holder = bd_find_holder_disk(bdev, disk);
> if (!WARN_ON_ONCE(holder == NULL) && !--holder->refcnt) {
> del_symlink(disk->slave_dir, bdev_kobj(bdev));
> @@ -149,6 +190,7 @@ void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk)
> list_del_init(&holder->list);
> kfree(holder);
> }
> + mutex_unlock(&slave_bdevs_lock);
> mutex_unlock(&disk->open_mutex);
> }
> EXPORT_SYMBOL_GPL(bd_unlink_disk_holder);
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH -next] block: don't allow a disk link holder to its ancestor
2023-10-08 1:14 ` Li Lingfeng
@ 2023-11-13 6:08 ` Li Lingfeng
0 siblings, 0 replies; 4+ messages in thread
From: Li Lingfeng @ 2023-11-13 6:08 UTC (permalink / raw)
To: hch, axboe
Cc: linux-block, linux-kernel, yukuai1, houtao1, yi.zhang,
lilingfeng3, yangerkun
Ping again
Thanks
在 2023/10/8 9:14, Li Lingfeng 写道:
> Friendly ping ...
>
> Thanks
>
> 在 2023/4/25 15:55, Li Lingfeng 写道:
>> From: Li Lingfeng <lilingfeng3@huawei.com>
>>
>> Previously commit 077a4033541f ("block: don't allow a disk link holder
>> to itself") prevent user from reloading dm with itself. However, user
>> can reload dm with its ancestor which will trigger dead loop and result
>> in oom.
>>
>> Test procedures:
>> 1) dmsetup create test --table "0 20971520 linear /dev/sdd 0"
>> 2) dmsetup create test1 --table "0 20971520 linear /dev/sdd 20971520"
>> 3) dmsetup suspend test
>> 4) dmsetup reload test --table "0 2048 linear /dev/mapper/test1 0"
>> 5) dmsetup resume test
>> 6) dmsetup suspend test1
>> 7) dmsetup reload test1 --table "0 2048 linear /dev/mapper/test 0"
>> 8) dmsetup resume test1
>>
>> Dead loop:
>> [ 229.681231] Call Trace:
>> [ 229.681232] dm_dax_supported+0x5b/0xa0
>> [ 229.681233] dax_supported+0x28/0x50
>> [ 229.681234] device_not_dax_capable+0x45/0x70
>> [ 229.681235] ? realloc_argv+0xa0/0xa0
>> [ 229.681236] linear_iterate_devices+0x25/0x30
>> [ 229.681237] dm_table_supports_dax+0x42/0xd0
>> [ 229.681238] dm_dax_supported+0x5b/0xa0
>> [ 229.681238] dax_supported+0x28/0x50
>> [ 229.681239] device_not_dax_capable+0x45/0x70
>> ......(a lot of same lines)
>> [ 229.681423] ? realloc_argv+0xa0/0xa0
>> [ 229.681424] linear_iterate_devices+0x25/0x30
>> [ 229.681425] dm_table_supports_dax+0x42/0xd0
>> [ 229.681426] dm
>> [ 229.681428] Lost 437 message(s)!
>> [ 229.825588] ---[ end trace 0f2a9db839ed5b56 ]---
>>
>> OOM:
>> [ 189.270011] Call Trace:
>> [ 189.270274] <TASK>
>> [ 189.270511] dump_stack_lvl+0xc1/0x170
>> [ 189.270899] dump_stack+0x14/0x20
>> [ 189.271222] dump_header+0x5a/0x710
>> [ 189.271590] oom_kill_process+0x16b/0x500
>> [ 189.272018] out_of_memory+0x333/0xad0
>> [ 189.272453] __alloc_pages_slowpath.constprop.0+0x18b4/0x1c40
>> [ 189.273130] ? find_held_lock+0x33/0xf0
>> [ 189.273637] __alloc_pages+0x598/0x660
>> [ 189.274106] alloc_pages+0x95/0x240
>> [ 189.274482] folio_alloc+0x1f/0x60
>> [ 189.274835] filemap_alloc_folio+0x223/0x350
>> [ 189.275348] __filemap_get_folio+0x21e/0x770
>> [ 189.275916] filemap_fault+0x72d/0xdc0
>> [ 189.276454] __do_fault+0x41/0x360
>> [ 189.276820] do_fault+0x263/0x8f0
>> [ 189.277175] __handle_mm_fault+0x9af/0x1b20
>> [ 189.277810] handle_mm_fault+0x128/0x570
>> [ 189.278243] do_user_addr_fault+0x2af/0xea0
>> [ 189.278733] exc_page_fault+0x73/0x340
>> [ 189.279133] asm_exc_page_fault+0x22/0x30
>> [ 189.279523] RIP: 0033:0x561e82ac67f0
>>
>> Forbidding a disk to create link to its ancestor can solve the problem.
>> What's more, limit device depth to prevent recursive overflow.
>>
>> Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com>
>> ---
>> block/holder.c | 42 ++++++++++++++++++++++++++++++++++++++++++
>> 1 file changed, 42 insertions(+)
>>
>> diff --git a/block/holder.c b/block/holder.c
>> index 37d18c13d958..6a8571b7d9c5 100644
>> --- a/block/holder.c
>> +++ b/block/holder.c
>> @@ -2,9 +2,13 @@
>> #include <linux/blkdev.h>
>> #include <linux/slab.h>
>> +#define DEVICE_DEPTH 5
>> +static DEFINE_MUTEX(slave_bdevs_lock);
>> +
>> struct bd_holder_disk {
>> struct list_head list;
>> struct kobject *holder_dir;
>> + struct gendisk *slave_disk;
>> int refcnt;
>> };
>> @@ -29,6 +33,32 @@ static void del_symlink(struct kobject *from,
>> struct kobject *to)
>> sysfs_remove_link(from, kobject_name(to));
>> }
>> +static struct gendisk *iterate_slave_disk(struct gendisk *disk,
>> + struct gendisk *target, int depth)
>> +{
>> + struct bd_holder_disk *holder;
>> + struct gendisk *iter_slave;
>> +
>> + if (!depth)
>> + return target;
>> +
>> + if (list_empty_careful(&disk->slave_bdevs))
>> + return NULL;
>> +
>> + depth--;
>> + list_for_each_entry(holder, &disk->slave_bdevs, list) {
>> + if (holder->slave_disk == target)
>> + return target;
>> +
>> + iter_slave = iterate_slave_disk(holder->slave_disk, target,
>> depth);
>> + if (iter_slave)
>> + return iter_slave;
>> +
>> + cond_resched();
>> + }
>> + return NULL;
>> +}
>> +
>> /**
>> * bd_link_disk_holder - create symlinks between holding disk and
>> slave bdev
>> * @bdev: the claimed slave bdev
>> @@ -62,6 +92,13 @@ int bd_link_disk_holder(struct block_device *bdev,
>> struct gendisk *disk)
>> struct bd_holder_disk *holder;
>> int ret = 0;
>> + mutex_lock(&slave_bdevs_lock);
>> + if (iterate_slave_disk(bdev->bd_disk, disk, DEVICE_DEPTH)) {
>> + mutex_unlock(&slave_bdevs_lock);
>> + return -EINVAL;
>> + }
>> + mutex_unlock(&slave_bdevs_lock);
>> +
>> if (WARN_ON_ONCE(!disk->slave_dir))
>> return -EINVAL;
>> @@ -81,6 +118,7 @@ int bd_link_disk_holder(struct block_device
>> *bdev, struct gendisk *disk)
>> mutex_unlock(&bdev->bd_disk->open_mutex);
>> mutex_lock(&disk->open_mutex);
>> + mutex_lock(&slave_bdevs_lock);
>> WARN_ON_ONCE(!bdev->bd_holder);
>> holder = bd_find_holder_disk(bdev, disk);
>> @@ -106,8 +144,10 @@ int bd_link_disk_holder(struct block_device
>> *bdev, struct gendisk *disk)
>> ret = add_symlink(bdev->bd_holder_dir, &disk_to_dev(disk)->kobj);
>> if (ret)
>> goto out_del_symlink;
>> + holder->slave_disk = bdev->bd_disk;
>> list_add(&holder->list, &disk->slave_bdevs);
>> + mutex_unlock(&slave_bdevs_lock);
>> mutex_unlock(&disk->open_mutex);
>> return 0;
>> @@ -141,6 +181,7 @@ void bd_unlink_disk_holder(struct block_device
>> *bdev, struct gendisk *disk)
>> return;
>> mutex_lock(&disk->open_mutex);
>> + mutex_lock(&slave_bdevs_lock);
>> holder = bd_find_holder_disk(bdev, disk);
>> if (!WARN_ON_ONCE(holder == NULL) && !--holder->refcnt) {
>> del_symlink(disk->slave_dir, bdev_kobj(bdev));
>> @@ -149,6 +190,7 @@ void bd_unlink_disk_holder(struct block_device
>> *bdev, struct gendisk *disk)
>> list_del_init(&holder->list);
>> kfree(holder);
>> }
>> + mutex_unlock(&slave_bdevs_lock);
>> mutex_unlock(&disk->open_mutex);
>> }
>> EXPORT_SYMBOL_GPL(bd_unlink_disk_holder);
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2023-11-13 6:09 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-04-25 7:55 [PATCH -next] block: don't allow a disk link holder to its ancestor Li Lingfeng
2023-04-25 8:13 ` Chaitanya Kulkarni
2023-10-08 1:14 ` Li Lingfeng
2023-11-13 6:08 ` Li Lingfeng
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®