Name
freeze_bdev —
- lock a filesystem and force it into a consistent state
Synopsis
struct super_block * freeze_bdev (struct block_device * bdev);
Description
This takes the block device bd_mount_sem to make sure no new mounts
happen on bdev until thaw_bdev is called.
If a superblock is found on this device, we take the s_umount semaphore
on it to make sure nobody unmounts until the snapshot creation is done.