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- jessie 3.16.56-1+deb8u1
FREEZE_BDEV(9) | The Linux VFS | FREEZE_BDEV(9) |
NAME¶
freeze_bdev - - lock a filesystem and force it into a consistent stateSYNOPSIS¶
struct super_block *
freeze_bdev(struct block_device * bdev);
ARGUMENTS¶
bdevblockdevice to lock
DESCRIPTION¶
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. The reference counter (bd_fsfreeze_count) guarantees that only the last unfreeze process can unfreeze the frozen filesystem actually when multiple freeze requests arrive simultaneously. It counts up in freeze_bdev and count down in thaw_bdev. When it becomes 0, thaw_bdev will unfreeze actually.COPYRIGHT¶
May 2018 | Kernel Hackers Manual 3.16 |