* may be used to exclude some operations from running concurrently without any
* modifications to the list (see write_all_supers)
*
- * volume_mutex
- * ------------
- * coarse lock owned by a mounted filesystem; used to exclude some operations
- * that cannot run in parallel and affect the higher-level properties of the
- * filesystem like: device add/deleting/resize/replace, or balance
- *
* balance_mutex
* -------------
* protects balance structures (status, state) and context accessed from
struct btrfs_device *tmp;
devices = &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 (test_bit(BTRFS_DEV_STATE_IN_FS_METADATA,
&tmp->dev_state) && !tmp->bdev) {
}
/*
- * Should be called with both balance and volume mutexes held to
- * serialize other volume operations (add_dev/rm_dev/resize) with
- * restriper. Same goes for reset_balance_state.
+ * Should be called with balance mutex held to protect against checking the
+ * balance status or progress. Same goes for reset_balance_state.
*/
static void set_balance_control(struct btrfs_balance_control *bctl)
{
}
/*
- * Should be called with both balance and volume mutexes held
+ * Should be called with balance mutexe held
*/
int btrfs_balance(struct btrfs_balance_control *bctl,
struct btrfs_ioctl_balance_args *bargs)
spin_unlock(&fs_info->balance_lock);
}
- atomic_inc(&fs_info->balance_running);
+ ASSERT(!test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags));
+ set_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags);
mutex_unlock(&fs_info->balance_mutex);
ret = __btrfs_balance(fs_info);
mutex_lock(&fs_info->balance_mutex);
- atomic_dec(&fs_info->balance_running);
+ clear_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags);
if (bargs) {
memset(bargs, 0, sizeof(*bargs));
- update_ioctl_balance_args(fs_info, 0, bargs);
+ btrfs_update_ioctl_balance_args(fs_info, bargs);
}
if ((ret && ret != -ECANCELED && ret != -ENOSPC) ||
struct btrfs_fs_info *fs_info = data;
int ret = 0;
- mutex_lock(&fs_info->volume_mutex);
mutex_lock(&fs_info->balance_mutex);
-
if (fs_info->balance_ctl) {
btrfs_info(fs_info, "continuing balance");
ret = btrfs_balance(fs_info->balance_ctl, NULL);
}
-
mutex_unlock(&fs_info->balance_mutex);
- mutex_unlock(&fs_info->volume_mutex);
return ret;
}
{
struct task_struct *tsk;
- spin_lock(&fs_info->balance_lock);
+ mutex_lock(&fs_info->balance_mutex);
if (!fs_info->balance_ctl) {
- spin_unlock(&fs_info->balance_lock);
+ mutex_unlock(&fs_info->balance_mutex);
return 0;
}
- spin_unlock(&fs_info->balance_lock);
+ mutex_unlock(&fs_info->balance_mutex);
if (btrfs_test_opt(fs_info, SKIP_BALANCE)) {
btrfs_info(fs_info, "force skipping balance");
btrfs_warn(fs_info,
"cannot set exclusive op status to balance, resume manually");
- mutex_lock(&fs_info->volume_mutex);
mutex_lock(&fs_info->balance_mutex);
-
set_balance_control(bctl);
-
mutex_unlock(&fs_info->balance_mutex);
- mutex_unlock(&fs_info->volume_mutex);
out:
btrfs_free_path(path);
return ret;
return -ENOTCONN;
}
- if (atomic_read(&fs_info->balance_running)) {
+ if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
atomic_inc(&fs_info->balance_pause_req);
mutex_unlock(&fs_info->balance_mutex);
wait_event(fs_info->balance_wait_q,
- atomic_read(&fs_info->balance_running) == 0);
+ !test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags));
mutex_lock(&fs_info->balance_mutex);
/* we are good with balance_ctl ripped off from under us */
- BUG_ON(atomic_read(&fs_info->balance_running));
+ BUG_ON(test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags));
atomic_dec(&fs_info->balance_pause_req);
} else {
ret = -ENOTCONN;
int btrfs_cancel_balance(struct btrfs_fs_info *fs_info)
{
- if (sb_rdonly(fs_info->sb))
- return -EROFS;
-
mutex_lock(&fs_info->balance_mutex);
if (!fs_info->balance_ctl) {
mutex_unlock(&fs_info->balance_mutex);
return -ENOTCONN;
}
+ /*
+ * A paused balance with the item stored on disk can be resumed at
+ * mount time if the mount is read-write. Otherwise it's still paused
+ * and we must not allow cancelling as it deletes the item.
+ */
+ if (sb_rdonly(fs_info->sb)) {
+ mutex_unlock(&fs_info->balance_mutex);
+ return -EROFS;
+ }
+
atomic_inc(&fs_info->balance_cancel_req);
/*
* if we are running just wait and return, balance item is
* deleted in btrfs_balance in this case
*/
- if (atomic_read(&fs_info->balance_running)) {
+ if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
mutex_unlock(&fs_info->balance_mutex);
wait_event(fs_info->balance_wait_q,
- atomic_read(&fs_info->balance_running) == 0);
+ !test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags));
mutex_lock(&fs_info->balance_mutex);
} else {
- /* reset_balance_state needs volume_mutex */
mutex_unlock(&fs_info->balance_mutex);
- mutex_lock(&fs_info->volume_mutex);
+ /*
+ * Lock released to allow other waiters to continue, we'll
+ * reexamine the status again.
+ */
mutex_lock(&fs_info->balance_mutex);
if (fs_info->balance_ctl) {
reset_balance_state(fs_info);
clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
}
-
- mutex_unlock(&fs_info->volume_mutex);
}
- BUG_ON(fs_info->balance_ctl || atomic_read(&fs_info->balance_running));
+ BUG_ON(fs_info->balance_ctl ||
+ test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags));
atomic_dec(&fs_info->balance_cancel_req);
mutex_unlock(&fs_info->balance_mutex);
return 0;
git.samba.org / sfrench / cifs-2.6.git / blobdiff