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 <h...@carfax.org.uk>
---
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 | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++-
5 files changed, 106 insertions(+), 2 deletions(-)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 3006287..25aa3cf 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -873,6 +873,11 @@ struct btrfs_block_group_cache {
struct list_head cluster_list;
};
+struct btrfs_balance_info {
+ u32 expected;
+ u32 completed;
+};
+
struct reloc_control;
struct btrfs_device;
struct btrfs_fs_devices;
@@ -1115,6 +1120,10 @@ struct btrfs_fs_info {
u64 fs_state;
struct btrfs_delayed_root *delayed_root;
+
+ /* 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 1ac8db5d..38f8fbc 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1619,6 +1619,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
spin_lock_init(&fs_info->fs_roots_radix_lock);
spin_lock_init(&fs_info->delayed_iput_lock);
spin_lock_init(&fs_info->defrag_inodes_lock);
+ spin_lock_init(&fs_info->balance_info_lock);
mutex_init(&fs_info->reloc_mutex);
init_completion(&fs_info->kobj_unregister);
@@ -1648,6 +1649,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
fs_info->metadata_ratio = 0;
fs_info->defrag_inodes = RB_ROOT;
fs_info->trans_no_join = 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 a3c4751..5ddf816 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2836,6 +2836,38 @@ static long btrfs_ioctl_scrub_progress(struct btrfs_root
*root,
return ret;
}
+/*
+ * 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)
{
@@ -2881,6 +2913,8 @@ long btrfs_ioctl(struct file *file, unsigned int
return btrfs_ioctl_dev_info(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 ad1ea78..575b25f 100644
--- a/fs/btrfs/ioctl.h
+++ b/fs/btrfs/ioctl.h
@@ -193,6 +193,11 @@ struct btrfs_ioctl_space_args {
struct btrfs_ioctl_space_info spaces[0];
};
+struct btrfs_ioctl_balance_progress {
+ __u32 expected;
+ __u32 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, \
@@ -248,4 +253,6 @@ struct btrfs_ioctl_space_args {
struct btrfs_ioctl_dev_info_args)
#define BTRFS_IOC_FS_INFO _IOR(BTRFS_IOCTL_MAGIC, 31, \
struct btrfs_ioctl_fs_info_args)
+#define BTRFS_IOC_BALANCE_PROGRESS _IOR(BTRFS_IOCTL_MAGIC, 32, \
+ struct btrfs_ioctl_balance_progress)
#endif
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 1efa56e..4c0a386 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2026,6 +2026,7 @@ 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;
@@ -2036,6 +2037,20 @@ 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 = -ENOMEM;
+ 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;
@@ -2059,10 +2074,37 @@ 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 = -ENOMEM;
+ 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_release_path(path);
+ /* step three, relocate all the chunks */
key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
key.offset = (u64)-1;
key.type = BTRFS_CHUNK_ITEM_KEY;
@@ -2100,10 +2142,20 @@ int btrfs_balance(struct btrfs_root *dev_root)
found_key.offset);
BUG_ON(ret && ret != -ENOSPC);
key.offset = found_key.offset - 1;
+ spin_lock(&dev_root->fs_info->balance_info_lock);
+ bal_info->completed++;
+ spin_unlock(&dev_root->fs_info->balance_info_lock);
+ printk(KERN_INFO "btrfs: balance: %u/%u block groups
completed\n",
+ bal_info->completed, bal_info->expected);
}
ret = 0;
error:
btrfs_free_path(path);
+ spin_lock(&dev_root->fs_info->balance_info_lock);
+ kfree(dev_root->fs_info->balance_info);
+ dev_root->fs_info->balance_info = NULL;
+ spin_unlock(&dev_root->fs_info->balance_info_lock);
+error_no_status:
mutex_unlock(&dev_root->fs_info->volume_mutex);
return ret;
}
--
1.7.2.5
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