Implement an ioctl for cancelling restriper. Currently we wait until
relocation of the current block group is finished, in future this can be
done by triggering a commit. Balance item is deleted and no memory
about the interrupted balance is kept.
Signed-off-by: Ilya Dryomov <idryomov@xxxxxxxxx>
---
fs/btrfs/ctree.h | 1 +
fs/btrfs/disk-io.c | 1 +
fs/btrfs/ioctl.c | 2 ++
fs/btrfs/ioctl.h | 1 +
fs/btrfs/volumes.c | 47 ++++++++++++++++++++++++++++++++++++++++++++---
fs/btrfs/volumes.h | 1 +
6 files changed, 50 insertions(+), 3 deletions(-)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 1afda75..dfc136c 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1216,6 +1216,7 @@ struct btrfs_fs_info {
struct mutex balance_mutex;
atomic_t balance_running;
atomic_t balance_pause_req;
+ atomic_t balance_cancel_req;
struct btrfs_balance_control *balance_ctl;
wait_queue_head_t balance_wait_q;
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 8ce8374..c23b82d 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2006,6 +2006,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
mutex_init(&fs_info->balance_mutex);
atomic_set(&fs_info->balance_running, 0);
atomic_set(&fs_info->balance_pause_req, 0);
+ atomic_set(&fs_info->balance_cancel_req, 0);
fs_info->balance_ctl = NULL;
init_waitqueue_head(&fs_info->balance_wait_q);
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 7830fae..d47ff8e 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3131,6 +3131,8 @@ static long btrfs_ioctl_balance_ctl(struct btrfs_root *root, int cmd)
switch (cmd) {
case BTRFS_BALANCE_CTL_PAUSE:
return btrfs_pause_balance(root->fs_info);
+ case BTRFS_BALANCE_CTL_CANCEL:
+ return btrfs_cancel_balance(root->fs_info);
}
return -EINVAL;
diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h
index f069138..33ec6d8 100644
--- a/fs/btrfs/ioctl.h
+++ b/fs/btrfs/ioctl.h
@@ -111,6 +111,7 @@ struct btrfs_ioctl_fs_info_args {
/* balance control ioctl modes */
#define BTRFS_BALANCE_CTL_PAUSE 1
+#define BTRFS_BALANCE_CTL_CANCEL 2
/*
* this is packed, because it should be exactly the same as its disk
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 9d15819..f7248c9 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2490,7 +2490,8 @@ static int __btrfs_balance(struct btrfs_fs_info *fs_info)
key.type = BTRFS_CHUNK_ITEM_KEY;
while (1) {
- if (atomic_read(&fs_info->balance_pause_req)) {
+ if (atomic_read(&fs_info->balance_pause_req) ||
+ atomic_read(&fs_info->balance_cancel_req)) {
ret = -ECANCELED;
goto error;
}
@@ -2556,7 +2557,10 @@ error:
static inline int balance_need_close(struct btrfs_fs_info *fs_info)
{
- return atomic_read(&fs_info->balance_pause_req) == 0;
+ /* cancel requested || normal exit path */
+ return atomic_read(&fs_info->balance_cancel_req) ||
+ (atomic_read(&fs_info->balance_pause_req) == 0 &&
+ atomic_read(&fs_info->balance_cancel_req) == 0);
}
static void __cancel_balance(struct btrfs_fs_info *fs_info)
@@ -2578,7 +2582,8 @@ int btrfs_balance(struct btrfs_balance_control *bctl, int resume)
int ret;
if (btrfs_fs_closing(fs_info) ||
- atomic_read(&fs_info->balance_pause_req)) {
+ atomic_read(&fs_info->balance_pause_req) ||
+ atomic_read(&fs_info->balance_cancel_req)) {
ret = -EINVAL;
goto out;
}
@@ -2818,6 +2823,42 @@ int btrfs_pause_balance(struct btrfs_fs_info *fs_info)
return ret;
}
+int btrfs_cancel_balance(struct btrfs_fs_info *fs_info)
+{
+ mutex_lock(&fs_info->balance_mutex);
+ if (!fs_info->balance_ctl) {
+ mutex_unlock(&fs_info->balance_mutex);
+ return -ENOTCONN;
+ }
+
+ 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)) {
+ mutex_unlock(&fs_info->balance_mutex);
+ wait_event(fs_info->balance_wait_q,
+ atomic_read(&fs_info->balance_running) == 0);
+ mutex_lock(&fs_info->balance_mutex);
+ } else {
+ /* __cancel_balance needs volume_mutex */
+ mutex_unlock(&fs_info->balance_mutex);
+ mutex_lock(&fs_info->volume_mutex);
+ mutex_lock(&fs_info->balance_mutex);
+
+ if (fs_info->balance_ctl)
+ __cancel_balance(fs_info);
+
+ mutex_unlock(&fs_info->volume_mutex);
+ }
+
+ BUG_ON(fs_info->balance_ctl || atomic_read(&fs_info->balance_running));
+ atomic_dec(&fs_info->balance_cancel_req);
+ mutex_unlock(&fs_info->balance_mutex);
+ return 0;
+}
+
/*
* shrinking a device means finding all of the device extents past
* the new size, and then following the back refs to the chunks.
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 2f74695..4429efc 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -272,6 +272,7 @@ int btrfs_init_new_device(struct btrfs_root *root, char *path);
int btrfs_balance(struct btrfs_balance_control *rctl, int resume);
int btrfs_recover_balance(struct btrfs_root *tree_root);
int btrfs_pause_balance(struct btrfs_fs_info *fs_info);
+int btrfs_cancel_balance(struct btrfs_fs_info *fs_info);
int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset);
int find_free_dev_extent(struct btrfs_trans_handle *trans,
struct btrfs_device *device, u64 num_bytes,
--
1.7.6.3
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
