Btrfs: implement online profile changing
Profile changing is done by launching a balance with
BTRFS_BALANCE_CONVERT bits set and target fields of respective
btrfs_balance_args structs initialized. Profile reducing code in this
case will pick restriper's target profile if it's available instead of
doing a blind reduce. If target profile is not yet available it goes
back to a plain reduce.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index e86c9e4..f08210e 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2438,6 +2438,75 @@
}
}
+ /*
+ * Profile changing sanity checks. Skip them if a simple
+ * balance is requested.
+ */
+ if (!((bctl->data.flags | bctl->sys.flags | bctl->meta.flags) &
+ BTRFS_BALANCE_ARGS_CONVERT))
+ goto do_balance;
+
+ allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
+ if (fs_info->fs_devices->num_devices == 1)
+ allowed |= BTRFS_BLOCK_GROUP_DUP;
+ else if (fs_info->fs_devices->num_devices < 4)
+ allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1);
+ else
+ allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
+ BTRFS_BLOCK_GROUP_RAID10);
+
+ if (!profile_is_valid(bctl->data.target, 1) ||
+ bctl->data.target & ~allowed) {
+ printk(KERN_ERR "btrfs: unable to start balance with target "
+ "data profile %llu\n",
+ (unsigned long long)bctl->data.target);
+ ret = -EINVAL;
+ goto out;
+ }
+ if (!profile_is_valid(bctl->meta.target, 1) ||
+ bctl->meta.target & ~allowed) {
+ printk(KERN_ERR "btrfs: unable to start balance with target "
+ "metadata profile %llu\n",
+ (unsigned long long)bctl->meta.target);
+ ret = -EINVAL;
+ goto out;
+ }
+ if (!profile_is_valid(bctl->sys.target, 1) ||
+ bctl->sys.target & ~allowed) {
+ printk(KERN_ERR "btrfs: unable to start balance with target "
+ "system profile %llu\n",
+ (unsigned long long)bctl->sys.target);
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (bctl->data.target & BTRFS_BLOCK_GROUP_DUP) {
+ printk(KERN_ERR "btrfs: dup for data is not allowed\n");
+ ret = -EINVAL;
+ goto out;
+ }
+
+ /* allow to reduce meta or sys integrity only if force set */
+ allowed = BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
+ BTRFS_BLOCK_GROUP_RAID10;
+ if (((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
+ (fs_info->avail_system_alloc_bits & allowed) &&
+ !(bctl->sys.target & allowed)) ||
+ ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
+ (fs_info->avail_metadata_alloc_bits & allowed) &&
+ !(bctl->meta.target & allowed))) {
+ if (bctl->flags & BTRFS_BALANCE_FORCE) {
+ printk(KERN_INFO "btrfs: force reducing metadata "
+ "integrity\n");
+ } else {
+ printk(KERN_ERR "btrfs: balance will reduce metadata "
+ "integrity, use force if you want this\n");
+ ret = -EINVAL;
+ goto out;
+ }
+ }
+
+do_balance:
set_balance_control(bctl);
mutex_unlock(&fs_info->balance_mutex);