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btrfs: zoned: clone zoned device info when cloning a device

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When cloning a btrfs_device, we're not cloning the associated
btrfs_zoned_device_info structure of the device in case of a zoned
filesystem.

Later on this leads to a NULL pointer dereference when accessing the
device's zone_info for instance when setting a zone as active.

This was uncovered by fstests' testcase btrfs/161.

CC: stable@vger.kernel.org # 5.15+
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Johannes Thumshirn 2022-11-04 07:12:33 -07:00 committed by David Sterba
parent b75b51f886
commit 21e61ec6d0
3 changed files with 63 additions and 0 deletions
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12
fs/btrfs/volumes.c
View File

@ -1011,6 +1011,18 @@ static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
rcu_assign_pointer(device->name, name);
}
if (orig_dev->zone_info) {
struct btrfs_zoned_device_info *zone_info;
zone_info = btrfs_clone_dev_zone_info(orig_dev);
if (!zone_info) {
btrfs_free_device(device);
ret = -ENOMEM;
goto error;
}
device->zone_info = zone_info;
}
list_add(&device->dev_list, &fs_devices->devices);
device->fs_devices = fs_devices;
fs_devices->num_devices++;

40
fs/btrfs/zoned.c
View File

@ -639,6 +639,46 @@ void btrfs_destroy_dev_zone_info(struct btrfs_device *device)
device->zone_info = NULL;
}
struct btrfs_zoned_device_info *btrfs_clone_dev_zone_info(struct btrfs_device *orig_dev)
{
struct btrfs_zoned_device_info *zone_info;
zone_info = kmemdup(orig_dev->zone_info, sizeof(*zone_info), GFP_KERNEL);
if (!zone_info)
return NULL;
zone_info->seq_zones = bitmap_zalloc(zone_info->nr_zones, GFP_KERNEL);
if (!zone_info->seq_zones)
goto out;
bitmap_copy(zone_info->seq_zones, orig_dev->zone_info->seq_zones,
zone_info->nr_zones);
zone_info->empty_zones = bitmap_zalloc(zone_info->nr_zones, GFP_KERNEL);
if (!zone_info->empty_zones)
goto out;
bitmap_copy(zone_info->empty_zones, orig_dev->zone_info->empty_zones,
zone_info->nr_zones);
zone_info->active_zones = bitmap_zalloc(zone_info->nr_zones, GFP_KERNEL);
if (!zone_info->active_zones)
goto out;
bitmap_copy(zone_info->active_zones, orig_dev->zone_info->active_zones,
zone_info->nr_zones);
zone_info->zone_cache = NULL;
return zone_info;
out:
bitmap_free(zone_info->seq_zones);
bitmap_free(zone_info->empty_zones);
bitmap_free(zone_info->active_zones);
kfree(zone_info);
return NULL;
}
int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
struct blk_zone *zone)
{

11
fs/btrfs/zoned.h
View File

@ -36,6 +36,7 @@ int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
int btrfs_get_dev_zone_info_all_devices(struct btrfs_fs_info *fs_info);
int btrfs_get_dev_zone_info(struct btrfs_device *device, bool populate_cache);
void btrfs_destroy_dev_zone_info(struct btrfs_device *device);
struct btrfs_zoned_device_info *btrfs_clone_dev_zone_info(struct btrfs_device *orig_dev);
int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info);
int btrfs_check_mountopts_zoned(struct btrfs_fs_info *info);
int btrfs_sb_log_location_bdev(struct block_device *bdev, int mirror, int rw,
@ -103,6 +104,16 @@ static inline int btrfs_get_dev_zone_info(struct btrfs_device *device,
static inline void btrfs_destroy_dev_zone_info(struct btrfs_device *device) { }
/*
* In case the kernel is compiled without CONFIG_BLK_DEV_ZONED we'll never call
* into btrfs_clone_dev_zone_info() so it's safe to return NULL here.
*/
static inline struct btrfs_zoned_device_info *btrfs_clone_dev_zone_info(
struct btrfs_device *orig_dev)
{
return NULL;
}
static inline int btrfs_check_zoned_mode(const struct btrfs_fs_info *fs_info)
{
if (!btrfs_is_zoned(fs_info))