UbiquitousOS
/
OpenCloudOS-Kernel
mirror of https://gitee.com/OpenCloudOS/OpenCloudOS-Kernel.git
11
0
Fork 0
Code Issues Projects Releases Wiki Activity

btrfs: reduce uuid_mutex critical section while scanning devices 

The generic block device lookup or cleanup does not need the uuid mutex,
that's only for the device_list_add.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Anand Jain 2018-04-12 10:29:24 +08:00 committed by David Sterba
parent 20a6800402
commit b6ed73bcb1
1 changed files with 5 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
fs/btrfs/volumes.c
View File

@ -1232,31 +1232,29 @@ int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
*/
bytenr = btrfs_sb_offset(0);
flags |= FMODE_EXCL;
mutex_lock(&uuid_mutex);
bdev = blkdev_get_by_path(path, flags, holder);
if (IS_ERR(bdev)) {
ret = PTR_ERR(bdev);
goto error;
}
if (IS_ERR(bdev))
return PTR_ERR(bdev);
if (btrfs_read_disk_super(bdev, bytenr, &page, &disk_super)) {
ret = -EINVAL;
goto error_bdev_put;
}
mutex_lock(&uuid_mutex);
device = device_list_add(path, disk_super);
if (IS_ERR(device))
ret = PTR_ERR(device);
else
*fs_devices_ret = device->fs_devices;
mutex_unlock(&uuid_mutex);
btrfs_release_disk_super(page);
error_bdev_put:
blkdev_put(bdev, flags);
error:
mutex_unlock(&uuid_mutex);
return ret;
}