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Btrfs: add two more find_device() methods

The new function btrfs_find_device_missing_or_by_path() will be
used for the device replace procedure. This function itself calls
the second new function btrfs_find_device_by_path().
Unfortunately, it is not possible to currently make the rest of the
code use these functions as well, since all functions that look
similar at first view are all a little bit different in what they
are doing. But in the future, new code could benefit from these
two new functions, and currently, device replace uses them.

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
master
Stefan Behrens 9 years ago
committed by Josef Bacik
parent
commit
7ba15b7d21
  1. 59
      fs/btrfs/volumes.c
  2. 5
      fs/btrfs/volumes.h

59
fs/btrfs/volumes.c

@ -1522,6 +1522,65 @@ error_undo:
goto error_brelse;
}
int btrfs_find_device_by_path(struct btrfs_root *root, char *device_path,
struct btrfs_device **device)
{
int ret = 0;
struct btrfs_super_block *disk_super;
u64 devid;
u8 *dev_uuid;
struct block_device *bdev;
struct buffer_head *bh;
*device = NULL;
ret = btrfs_get_bdev_and_sb(device_path, FMODE_READ,
root->fs_info->bdev_holder, 0, &bdev, &bh);
if (ret)
return ret;
disk_super = (struct btrfs_super_block *)bh->b_data;
devid = btrfs_stack_device_id(&disk_super->dev_item);
dev_uuid = disk_super->dev_item.uuid;
*device = btrfs_find_device(root, devid, dev_uuid,
disk_super->fsid);
brelse(bh);
if (!*device)
ret = -ENOENT;
blkdev_put(bdev, FMODE_READ);
return ret;
}
int btrfs_find_device_missing_or_by_path(struct btrfs_root *root,
char *device_path,
struct btrfs_device **device)
{
*device = NULL;
if (strcmp(device_path, "missing") == 0) {
struct list_head *devices;
struct btrfs_device *tmp;
devices = &root->fs_info->fs_devices->devices;
/*
* It is safe to read the devices since the volume_mutex
* is held by the caller.
*/
list_for_each_entry(tmp, devices, dev_list) {
if (tmp->in_fs_metadata && !tmp->bdev) {
*device = tmp;
break;
}
}
if (!*device) {
pr_err("btrfs: no missing device found\n");
return -ENOENT;
}
return 0;
} else {
return btrfs_find_device_by_path(root, device_path, device);
}
}
/*
* does all the dirty work required for changing file system's UUID.
*/

5
fs/btrfs/volumes.h

@ -268,6 +268,11 @@ int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
struct btrfs_fs_devices **fs_devices_ret);
int btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
void btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices);
int btrfs_find_device_missing_or_by_path(struct btrfs_root *root,
char *device_path,
struct btrfs_device **device);
int btrfs_find_device_by_path(struct btrfs_root *root, char *device_path,
struct btrfs_device **device);
int btrfs_add_device(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_device *device);

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