Btrfs: allow for pausing restriper
Implement an ioctl for pausing restriper. This pauses the relocation,
but balance is still considered to be "in progress": balance item is
not deleted, other volume operations cannot be started, etc. If paused
in the middle of profile changing operation we will continue making
allocations with the target profile.
Add a hook to close_ctree() to pause restriper and free its data
structures on unmount. (It's safe to unmount when restriper is in
"paused" state, we will resume with the same parameters on the next
mount)
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 29b3a94..f572c53 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3072,6 +3072,11 @@
bargs->flags = bctl->flags;
+ if (atomic_read(&fs_info->balance_running))
+ bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
+ if (atomic_read(&fs_info->balance_pause_req))
+ bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
+
memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
@@ -3103,6 +3108,11 @@
bargs = NULL;
}
+ if (fs_info->balance_ctl) {
+ ret = -EINPROGRESS;
+ goto out_bargs;
+ }
+
bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
if (!bctl) {
ret = -ENOMEM;
@@ -3123,7 +3133,8 @@
ret = btrfs_balance(bctl, bargs);
/*
- * bctl is freed in __cancel_balance
+ * bctl is freed in __cancel_balance or in free_fs_info if
+ * restriper was paused all the way until unmount
*/
if (arg) {
if (copy_to_user(arg, bargs, sizeof(*bargs)))
@@ -3138,6 +3149,19 @@
return ret;
}
+static long btrfs_ioctl_balance_ctl(struct btrfs_root *root, int cmd)
+{
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ switch (cmd) {
+ case BTRFS_BALANCE_CTL_PAUSE:
+ return btrfs_pause_balance(root->fs_info);
+ }
+
+ return -EINVAL;
+}
+
long btrfs_ioctl(struct file *file, unsigned int
cmd, unsigned long arg)
{
@@ -3216,6 +3240,8 @@
return btrfs_ioctl_scrub_progress(root, argp);
case BTRFS_IOC_BALANCE_V2:
return btrfs_ioctl_balance(root, argp);
+ case BTRFS_IOC_BALANCE_CTL:
+ return btrfs_ioctl_balance_ctl(root, arg);
}
return -ENOTTY;