btrfs: make use of btrfs_scratch_superblocks() in btrfs_rm_device()

With the previous patches now the btrfs_scratch_superblocks() is ready to
be used in btrfs_rm_device() so use it.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
[ use GFP_KERNEL ]
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Anand Jain 2016-02-13 10:01:38 +08:00 committed by David Sterba
parent b3d1b1532f
commit 42b6742715

View File

@ -1752,13 +1752,11 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
{ {
struct btrfs_device *device; struct btrfs_device *device;
struct btrfs_device *next_device; struct btrfs_device *next_device;
struct block_device *bdev = NULL;
struct buffer_head *bh = NULL;
struct btrfs_super_block *disk_super = NULL;
struct btrfs_fs_devices *cur_devices; struct btrfs_fs_devices *cur_devices;
u64 num_devices; u64 num_devices;
int ret = 0; int ret = 0;
bool clear_super = false; bool clear_super = false;
char *dev_name = NULL;
mutex_lock(&uuid_mutex); mutex_lock(&uuid_mutex);
@ -1786,6 +1784,11 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
list_del_init(&device->dev_alloc_list); list_del_init(&device->dev_alloc_list);
device->fs_devices->rw_devices--; device->fs_devices->rw_devices--;
unlock_chunks(root); unlock_chunks(root);
dev_name = kstrdup(device->name->str, GFP_KERNEL);
if (!dev_name) {
ret = -ENOMEM;
goto error_undo;
}
clear_super = true; clear_super = true;
} }
@ -1869,73 +1872,19 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
* remove it from the devices list and zero out the old super * remove it from the devices list and zero out the old super
*/ */
if (clear_super) { if (clear_super) {
u64 bytenr; struct block_device *bdev;
int i;
if (!disk_super) { bdev = blkdev_get_by_path(dev_name, FMODE_READ | FMODE_EXCL,
ret = btrfs_get_bdev_and_sb(device_path, root->fs_info->bdev_holder);
FMODE_WRITE | FMODE_EXCL, if (!IS_ERR(bdev)) {
root->fs_info->bdev_holder, 0, btrfs_scratch_superblocks(bdev, dev_name);
&bdev, &bh);
if (ret) {
/*
* It could be a failed device ok for clear_super
* to fail. So return success
*/
ret = 0;
goto out;
}
disk_super = (struct btrfs_super_block *)bh->b_data;
}
/* make sure this device isn't detected as part of
* the FS anymore
*/
memset(&disk_super->magic, 0, sizeof(disk_super->magic));
set_buffer_dirty(bh);
sync_dirty_buffer(bh);
brelse(bh);
/* clear the mirror copies of super block on the disk
* being removed, 0th copy is been taken care above and
* the below would take of the rest
*/
for (i = 1; i < BTRFS_SUPER_MIRROR_MAX; i++) {
bytenr = btrfs_sb_offset(i);
if (bytenr + BTRFS_SUPER_INFO_SIZE >=
i_size_read(bdev->bd_inode))
break;
bh = __bread(bdev, bytenr / 4096,
BTRFS_SUPER_INFO_SIZE);
if (!bh)
continue;
disk_super = (struct btrfs_super_block *)bh->b_data;
if (btrfs_super_bytenr(disk_super) != bytenr ||
btrfs_super_magic(disk_super) != BTRFS_MAGIC) {
brelse(bh);
continue;
}
memset(&disk_super->magic, 0,
sizeof(disk_super->magic));
set_buffer_dirty(bh);
sync_dirty_buffer(bh);
brelse(bh);
}
if (bdev) {
/* Notify udev that device has changed */
btrfs_kobject_uevent(bdev, KOBJ_CHANGE);
/* Update ctime/mtime for device path for libblkid */
update_dev_time(device_path);
blkdev_put(bdev, FMODE_READ | FMODE_EXCL); blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
} }
} }
out: out:
kfree(dev_name);
mutex_unlock(&uuid_mutex); mutex_unlock(&uuid_mutex);
return ret; return ret;