This patch introduces a basic form of progress monitoring for balance
operations, by counting the number of block groups remaining. The
information is exposed to userspace by an ioctl.
Signed-off-by: Hugo Mills<hugo@xxxxxxxxxxxxx>
---
fs/btrfs/ctree.h | 9 +++++++
fs/btrfs/disk-io.c | 2 +
fs/btrfs/ioctl.c | 34 +++++++++++++++++++++++++++++
fs/btrfs/ioctl.h | 7 ++++++
fs/btrfs/volumes.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++++-
5 files changed, 111 insertions(+), 2 deletions(-)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 7f78cc7..6c5526c 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -865,6 +865,11 @@ struct btrfs_block_group_cache {
struct list_head cluster_list;
};
+struct btrfs_balance_info {
+ u64 expected;
+ u64 completed;
+};
+
struct reloc_control;
struct btrfs_device;
struct btrfs_fs_devices;
@@ -1078,6 +1083,10 @@ struct btrfs_fs_info {
/* filesystem state */
u64 fs_state;
+
+ /* Keep track of any rebalance operations on this FS */
+ spinlock_t balance_info_lock;
+ struct btrfs_balance_info *balance_info;
};
/*
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 100b07f..3d690de 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1645,6 +1645,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
spin_lock_init(&fs_info->ref_cache_lock);
spin_lock_init(&fs_info->fs_roots_radix_lock);
spin_lock_init(&fs_info->delayed_iput_lock);
+ spin_lock_init(&fs_info->balance_info_lock);
init_completion(&fs_info->kobj_unregister);
fs_info->tree_root = tree_root;
@@ -1670,6 +1671,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
fs_info->sb = sb;
fs_info->max_inline = 8192 * 1024;
fs_info->metadata_ratio = 0;
+ fs_info->balance_info = NULL;
fs_info->thread_pool_size = min_t(unsigned long,
num_online_cpus() + 2, 8);
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 5fdb2ab..a8fbb07 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2375,6 +2375,38 @@ static noinline long btrfs_ioctl_wait_sync(struct file *file, void __user *argp)
return btrfs_wait_for_commit(root, transid);
}
+/*
+ * Return the current status of any balance operation
+ */
+long btrfs_ioctl_balance_progress(
+ struct btrfs_fs_info *fs_info,
+ struct btrfs_ioctl_balance_progress __user *user_dest)
+{
+ int ret = 0;
+ struct btrfs_ioctl_balance_progress dest;
+
+ spin_lock(&fs_info->balance_info_lock);
+ if (!fs_info->balance_info) {
+ ret = -EINVAL;
+ goto error;
+ }
+
+ dest.expected = fs_info->balance_info->expected;
+ dest.completed = fs_info->balance_info->completed;
+
+ spin_unlock(&fs_info->balance_info_lock);
+
+ if (copy_to_user(user_dest,&dest,
+ sizeof(struct btrfs_ioctl_balance_progress)))
+ return -EFAULT;
+
+ return 0;
+
+error:
+ spin_unlock(&fs_info->balance_info_lock);
+ return ret;
+}
+
long btrfs_ioctl(struct file *file, unsigned int
cmd, unsigned long arg)
{
@@ -2414,6 +2446,8 @@ long btrfs_ioctl(struct file *file, unsigned int
return btrfs_ioctl_rm_dev(root, argp);
case BTRFS_IOC_BALANCE:
return btrfs_balance(root->fs_info->dev_root);
+ case BTRFS_IOC_BALANCE_PROGRESS:
+ return btrfs_ioctl_balance_progress(root->fs_info, argp);
case BTRFS_IOC_CLONE:
return btrfs_ioctl_clone(file, arg, 0, 0, 0);
case BTRFS_IOC_CLONE_RANGE:
diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h
index 8fb3821..4c82d40 100644
--- a/fs/btrfs/ioctl.h
+++ b/fs/btrfs/ioctl.h
@@ -157,6 +157,11 @@ struct btrfs_ioctl_space_args {
struct btrfs_ioctl_space_info spaces[0];
};
+struct btrfs_ioctl_balance_progress {
+ __u64 expected;
+ __u64 completed;
+};
+
#define BTRFS_IOC_SNAP_CREATE _IOW(BTRFS_IOCTL_MAGIC, 1, \
struct btrfs_ioctl_vol_args)
#define BTRFS_IOC_DEFRAG _IOW(BTRFS_IOCTL_MAGIC, 2, \
@@ -203,4 +208,6 @@ struct btrfs_ioctl_space_args {
struct btrfs_ioctl_vol_args_v2)
#define BTRFS_IOC_SUBVOL_GETFLAGS _IOW(BTRFS_IOCTL_MAGIC, 25, __u64)
#define BTRFS_IOC_SUBVOL_SETFLAGS _IOW(BTRFS_IOCTL_MAGIC, 26, __u64)
+#define BTRFS_IOC_BALANCE_PROGRESS _IOR(BTRFS_IOCTL_MAGIC, 27, \
+ struct btrfs_ioctl_balance_progress)
#endif
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index dd13eb8..2bd4565 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2041,6 +2041,7 @@ int btrfs_balance(struct btrfs_root *dev_root)
struct btrfs_root *chunk_root = dev_root->fs_info->chunk_root;
struct btrfs_trans_handle *trans;
struct btrfs_key found_key;
+ struct btrfs_balance_info *bal_info;
if (dev_root->fs_info->sb->s_flags& MS_RDONLY)
return -EROFS;
@@ -2051,6 +2052,20 @@ int btrfs_balance(struct btrfs_root *dev_root)
mutex_lock(&dev_root->fs_info->volume_mutex);
dev_root = dev_root->fs_info->dev_root;
+ bal_info = kmalloc(
+ sizeof(struct btrfs_balance_info),
+ GFP_NOFS);
+ if (!bal_info) {
+ ret = -ENOSPC;
+ goto error_no_status;
+ }
+ spin_lock(&dev_root->fs_info->balance_info_lock);
+ dev_root->fs_info->balance_info = bal_info;
+ bal_info->expected = -1; /* One less than actually counted,
+ because chunk 0 is special */
+ bal_info->completed = 0;
+ spin_unlock(&dev_root->fs_info->balance_info_lock);
+
/* step one make some room on all the devices */
list_for_each_entry(device, devices, dev_list) {
old_size = device->total_bytes;
@@ -2074,10 +2089,42 @@ int btrfs_balance(struct btrfs_root *dev_root)
btrfs_end_transaction(trans, dev_root);
}
- /* step two, relocate all the chunks */
+ /* step two, count the chunks */
path = btrfs_alloc_path();
- BUG_ON(!path);
+ if (!path) {
+ ret = -ENOSPC;
+ goto error;
+ }
+
+ key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
+ key.offset = (u64)-1;
+ key.type = BTRFS_CHUNK_ITEM_KEY;
+
+ ret = btrfs_search_slot(NULL, chunk_root,&key, path, 0, 0);
+ if (ret<= 0) {
+ printk(KERN_ERR "btrfs: Failed to find the last chunk.\n");
+ BUG();
+ }
+
+ while (1) {
+ ret = btrfs_previous_item(chunk_root, path, 0,
+ BTRFS_CHUNK_ITEM_KEY);
+ if (ret)
+ break;
+
+ spin_lock(&dev_root->fs_info->balance_info_lock);
+ bal_info->expected++;
+ spin_unlock(&dev_root->fs_info->balance_info_lock);
+ }
+
+ btrfs_free_path(path);
+ path = btrfs_alloc_path();
+ if (!path) {
+ ret = -ENOSPC;
+ goto error;
+ }
