Btrfs: Make the resizer work based on shrinking and growing devices

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 28 insertions, 8 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index b31f52d4f2ca..4d12aa532c5b 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -16,6 +16,7 @@
  * Boston, MA 021110-1307, USA.
  */
 
+#include <linux/kernel.h>
 #include <linux/bio.h>
 #include <linux/buffer_head.h>
 #include <linux/fs.h>
@@ -2887,9 +2888,12 @@ static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg)
 {
         u64 new_size;
         u64 old_size;
+        u64 devid = 1;
         struct btrfs_ioctl_vol_args *vol_args;
         struct btrfs_trans_handle *trans;
+        struct btrfs_device *device = NULL;
         char *sizestr;
+        char *devstr = NULL;
         int ret = 0;
         int namelen;
         int mod = 0;
@@ -2909,9 +2913,25 @@ static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg)
                 goto out;
         }
 
+        mutex_lock(&root->fs_info->fs_mutex);
         sizestr = vol_args->name;
+        devstr = strchr(sizestr, ':');
+        if (devstr) {
+                char *end;
+                sizestr = devstr + 1;
+                *devstr = '\0';
+                devstr = vol_args->name;
+                devid = simple_strtoull(devstr, &end, 10);
+printk("resizing devid %Lu\n", devid);
+        }
+        device = btrfs_find_device(root, devid, NULL);
+        if (!device) {
+                printk("resizer unable to find device %Lu\n", devid);
+                ret = -EINVAL;
+                goto out_unlock;
+        }
         if (!strcmp(sizestr, "max"))
-                new_size = root->fs_info->sb->s_bdev->bd_inode->i_size;
+                new_size = device->bdev->bd_inode->i_size;
         else {
                 if (sizestr[0] == '-') {
                         mod = -1;
@@ -2923,12 +2943,11 @@ static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg)
                 new_size = btrfs_parse_size(sizestr);
                 if (new_size == 0) {
                         ret = -EINVAL;
-                        goto out;
+                        goto out_unlock;
                 }
         }
 
-        mutex_lock(&root->fs_info->fs_mutex);
-        old_size = btrfs_super_total_bytes(&root->fs_info->super_copy);
+        old_size = device->total_bytes;
 
         if (mod < 0) {
                 if (new_size > old_size) {
@@ -2944,7 +2963,7 @@ static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg)
                 ret = -EINVAL;
                 goto out_unlock;
         }
-        if (new_size > root->fs_info->sb->s_bdev->bd_inode->i_size) {
+        if (new_size > device->bdev->bd_inode->i_size) {
                 ret = -EFBIG;
                 goto out_unlock;
         }
@@ -2952,13 +2971,14 @@ static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg)
         do_div(new_size, root->sectorsize);
         new_size *= root->sectorsize;
 
-printk("new size is %Lu\n", new_size);
+printk("new size for %s is %llu\n", device->name, (unsigned long long)new_size);
+
         if (new_size > old_size) {
                 trans = btrfs_start_transaction(root, 1);
-                ret = btrfs_grow_extent_tree(trans, root, new_size);
+                ret = btrfs_grow_device(trans, device, new_size);
                 btrfs_commit_transaction(trans, root);
         } else {
-                ret = btrfs_shrink_extent_tree(root, new_size);
+                ret = btrfs_shrink_device(device, new_size);
         }
 
 out_unlock: