diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 99eb2bcd9aa7..1afda75d5414 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1214,7 +1214,10 @@ struct btrfs_fs_info {
/* restriper state */
spinlock_t balance_lock;
struct mutex balance_mutex;
+ atomic_t balance_running;
+ atomic_t balance_pause_req;
struct btrfs_balance_control *balance_ctl;
+ wait_queue_head_t balance_wait_q;
unsigned data_chunk_allocations;
unsigned metadata_ratio;
@@ -2658,6 +2661,7 @@ static inline int btrfs_fs_closing(struct btrfs_fs_info *fs_info)
}
static inline void free_fs_info(struct btrfs_fs_info *fs_info)
{
+ kfree(fs_info->balance_ctl);
kfree(fs_info->delayed_root);
kfree(fs_info->extent_root);
kfree(fs_info->tree_root);
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index eb7a11ac5b73..8ce837407800 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2004,7 +2004,10 @@ struct btrfs_root *open_ctree(struct super_block *sb,
spin_lock_init(&fs_info->balance_lock);
mutex_init(&fs_info->balance_mutex);
+ atomic_set(&fs_info->balance_running, 0);
+ atomic_set(&fs_info->balance_pause_req, 0);
fs_info->balance_ctl = NULL;
+ init_waitqueue_head(&fs_info->balance_wait_q);
sb->s_blocksize = 4096;
sb->s_blocksize_bits = blksize_bits(4096);
@@ -2980,6 +2983,9 @@ int close_ctree(struct btrfs_root *root)
fs_info->closing = 1;
smp_mb();
+ /* pause restriper - we want to resume on mount */
+ btrfs_pause_balance(root->fs_info);
+
btrfs_scrub_cancel(root);
/* wait for any defraggers to finish */
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 29b3a94933f0..f572c53dda4f 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3072,6 +3072,11 @@ void update_ioctl_balance_args(struct btrfs_fs_info *fs_info,
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 @@ static long btrfs_ioctl_balance(struct btrfs_root *root, void __user *arg)
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 @@ static long btrfs_ioctl_balance(struct btrfs_root *root, void __user *arg)
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 @@ static long btrfs_ioctl_balance(struct btrfs_root *root, void __user *arg)
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 @@ long btrfs_ioctl(struct file *file, unsigned int
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;
diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h
index c8b37d2c0d77..e972e11a8d77 100644
--- a/fs/btrfs/ioctl.h
+++ b/fs/btrfs/ioctl.h
@@ -109,6 +109,9 @@ struct btrfs_ioctl_fs_info_args {
__u64 reserved[124]; /* pad to 1k */
};
+/* balance control ioctl modes */
+#define BTRFS_BALANCE_CTL_PAUSE 1
+
/*
* this is packed, because it should be exactly the same as its disk
* byte order counterpart (struct btrfs_disk_balance_args)
@@ -137,6 +140,9 @@ struct btrfs_balance_progress {
__u64 completed; /* # of chunks relocated so far */
};
+#define BTRFS_BALANCE_STATE_RUNNING (1ULL << 0)
+#define BTRFS_BALANCE_STATE_PAUSE_REQ (1ULL << 1)
+
struct btrfs_ioctl_balance_args {
__u64 flags; /* in/out */
__u64 state; /* out */
@@ -315,6 +321,7 @@ struct btrfs_ioctl_logical_ino_args {
struct btrfs_ioctl_fs_info_args)
#define BTRFS_IOC_BALANCE_V2 _IOWR(BTRFS_IOCTL_MAGIC, 32, \
struct btrfs_ioctl_balance_args)
+#define BTRFS_IOC_BALANCE_CTL _IOW(BTRFS_IOCTL_MAGIC, 33, int)
#define BTRFS_IOC_INO_PATHS _IOWR(BTRFS_IOCTL_MAGIC, 35, \
struct btrfs_ioctl_ino_path_args)
#define BTRFS_IOC_LOGICAL_INO _IOWR(BTRFS_IOCTL_MAGIC, 36, \
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index e0160607e6e2..d32660ce753d 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2492,6 +2492,11 @@ 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)) {
+ ret = -ECANCELED;
+ goto error;
+ }
+
ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
if (ret < 0)
goto error;
@@ -2553,6 +2558,11 @@ static int __btrfs_balance(struct btrfs_fs_info *fs_info)
return ret;
}
+static inline int balance_need_close(struct btrfs_fs_info *fs_info)
+{
+ return atomic_read(&fs_info->balance_pause_req) == 0;
+}
+
static void __cancel_balance(struct btrfs_fs_info *fs_info)
{
int ret;
@@ -2575,7 +2585,8 @@ int btrfs_balance(struct btrfs_balance_control *bctl,
u64 allowed;
int ret;
- if (btrfs_fs_closing(fs_info)) {
+ if (btrfs_fs_closing(fs_info) ||
+ atomic_read(&fs_info->balance_pause_req)) {
ret = -EINVAL;
goto out;
}
@@ -2680,18 +2691,25 @@ int btrfs_balance(struct btrfs_balance_control *bctl,
spin_unlock(&fs_info->balance_lock);
}
+ atomic_inc(&fs_info->balance_running);
mutex_unlock(&fs_info->balance_mutex);
ret = __btrfs_balance(fs_info);
mutex_lock(&fs_info->balance_mutex);
+ atomic_dec(&fs_info->balance_running);
if (bargs) {
memset(bargs, 0, sizeof(*bargs));
update_ioctl_balance_args(fs_info, bargs);
}
- __cancel_balance(fs_info);
+ if ((ret && ret != -ECANCELED && ret != -ENOSPC) ||
+ balance_need_close(fs_info)) {
+ __cancel_balance(fs_info);
+ }
+
+ wake_up(&fs_info->balance_wait_q);
return ret;
out:
@@ -2785,6 +2803,35 @@ int btrfs_recover_balance(struct btrfs_root *tree_root)
return ret;
}
+int btrfs_pause_balance(struct btrfs_fs_info *fs_info)
+{
+ int ret = 0;
+
+ mutex_lock(&fs_info->balance_mutex);
+ if (!fs_info->balance_ctl) {
+ mutex_unlock(&fs_info->balance_mutex);
+ return -ENOTCONN;
+ }
+
+ if (atomic_read(&fs_info->balance_running)) {
+ 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);
+
+ 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));
+ atomic_dec(&fs_info->balance_pause_req);
+ } else {
+ ret = -ENOTCONN;
+ }
+
+ mutex_unlock(&fs_info->balance_mutex);
+ return ret;
+}
+
/*
* 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 cd25ea58ec35..80953afb12b9 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -273,6 +273,7 @@ int btrfs_init_new_device(struct btrfs_root *root, char *path);
int btrfs_balance(struct btrfs_balance_control *bctl,
struct btrfs_ioctl_balance_args *bargs);
int btrfs_recover_balance(struct btrfs_root *tree_root);
+int btrfs_pause_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,