btrfs: allow scanning multiple devices during mount
Allows to specify one or multiple device=/dev/foo options during mount
so that ioctls on the control device can be avoided. Especially useful
when trying to mount a multi-device setup as root.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 288300f..346932e 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -65,7 +65,7 @@
}
enum {
- Opt_degraded, Opt_subvol, Opt_nodatasum, Opt_nodatacow,
+ Opt_degraded, Opt_subvol, Opt_device, Opt_nodatasum, Opt_nodatacow,
Opt_max_extent, Opt_max_inline, Opt_alloc_start, Opt_nobarrier,
Opt_ssd, Opt_err,
};
@@ -73,6 +73,7 @@
static match_table_t tokens = {
{Opt_degraded, "degraded"},
{Opt_subvol, "subvol=%s"},
+ {Opt_device, "device=%s"},
{Opt_nodatasum, "nodatasum"},
{Opt_nodatacow, "nodatacow"},
{Opt_nobarrier, "nobarrier"},
@@ -142,8 +143,9 @@
btrfs_set_opt(info->mount_opt, DEGRADED);
break;
case Opt_subvol:
+ case Opt_device:
/*
- * This one is parsed by btrfs_parse_early_options
+ * These are parsed by btrfs_parse_early_options
* and can be happily ignored here.
*/
break;
@@ -212,8 +214,9 @@
* All other options will be parsed on much later in the mount process and
* only when we need to allocate a new super block.
*/
-static int btrfs_parse_early_options(const char *options,
- char **subvol_name)
+static int btrfs_parse_early_options(const char *options, int flags,
+ void *holder, char **subvol_name,
+ struct btrfs_fs_devices **fs_devices)
{
substring_t args[MAX_OPT_ARGS];
char *opts, *p;
@@ -240,11 +243,18 @@
case Opt_subvol:
*subvol_name = match_strdup(&args[0]);
break;
+ case Opt_device:
+ error = btrfs_scan_one_device(match_strdup(&args[0]),
+ flags, holder, fs_devices);
+ if (error)
+ goto out_free_opts;
+ break;
default:
break;
}
}
+ out_free_opts:
kfree(opts);
out:
/*
@@ -380,7 +390,8 @@
struct btrfs_fs_devices *fs_devices = NULL;
int error = 0;
- error = btrfs_parse_early_options(data, &subvol_name);
+ error = btrfs_parse_early_options(data, flags, fs_type,
+ &subvol_name, &fs_devices);
if (error)
goto error;