Experimental patch to be able to compact only the metadata after
clustered allocation allocated lots of unnecessary metadata block
groups. It's also useful to measure performance differences between
-o cluster and -o nocluster.
I guess it should be implemented as a balance option rather than a
separate ioctl, but this was good enough for me to try it.
Signed-off-by: Alexandre Oliva <oliva@xxxxxxxxxxxxxxxxx>
---
fs/btrfs/ioctl.c | 2 ++
fs/btrfs/ioctl.h | 3 +++
fs/btrfs/volumes.c | 33 ++++++++++++++++++++++++++++-----
fs/btrfs/volumes.h | 1 +
4 files changed, 34 insertions(+), 5 deletions(-)
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 4a34c47..69bf6f2 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3074,6 +3074,8 @@ 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_METADATA:
+ return btrfs_balance_metadata(root->fs_info->dev_root);
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 252ae99..46bc428 100644
--- a/fs/btrfs/ioctl.h
+++ b/fs/btrfs/ioctl.h
@@ -277,4 +277,7 @@ struct btrfs_ioctl_logical_ino_args {
#define BTRFS_IOC_LOGICAL_INO _IOWR(BTRFS_IOCTL_MAGIC, 36, \
struct btrfs_ioctl_ino_path_args)
+#define BTRFS_IOC_BALANCE_METADATA _IOW(BTRFS_IOCTL_MAGIC, 37, \
+ struct btrfs_ioctl_vol_args)
+
#endif
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index f8e29431..4d5b29f 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2077,7 +2077,7 @@ static u64 div_factor(u64 num, int factor)
return num;
}
-int btrfs_balance(struct btrfs_root *dev_root)
+static int btrfs_balance_skip(struct btrfs_root *dev_root, u64 skip_type)
{
int ret;
struct list_head *devices = &dev_root->fs_info->fs_devices->devices;
@@ -2089,6 +2089,9 @@ 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_chunk *chunk;
+ u64 chunk_type;
+ bool skip;
if (dev_root->fs_info->sb->s_flags & MS_RDONLY)
return -EROFS;
@@ -2158,11 +2161,21 @@ int btrfs_balance(struct btrfs_root *dev_root)
if (found_key.offset == 0)
break;
+ if (skip_type) {
+ chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_chunk);
+ chunk_type = btrfs_chunk_type(path->nodes[0], chunk);
+ skip = (chunk_type & skip_type);
+ } else
+ skip = false;
+
btrfs_release_path(path);
- ret = btrfs_relocate_chunk(chunk_root,
- chunk_root->root_key.objectid,
- found_key.objectid,
- found_key.offset);
+
+ ret = (skip ? 0 :
+ btrfs_relocate_chunk(chunk_root,
+ chunk_root->root_key.objectid,
+ found_key.objectid,
+ found_key.offset));
if (ret && ret != -ENOSPC)
goto error;
key.offset = found_key.offset - 1;
@@ -2174,6 +2187,16 @@ error:
return ret;
}
+int btrfs_balance(struct btrfs_root *dev_root)
+{
+ return btrfs_balance_skip(dev_root, 0);
+}
+
+int btrfs_balance_metadata(struct btrfs_root *dev_root)
+{
+ return btrfs_balance_skip(dev_root, BTRFS_BLOCK_GROUP_DATA);
+}
+
/*
* 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 ab5b1c4..c467499 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -223,6 +223,7 @@ struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
int btrfs_shrink_device(struct btrfs_device *device, u64 new_size);
int btrfs_init_new_device(struct btrfs_root *root, char *path);
int btrfs_balance(struct btrfs_root *dev_root);
+int btrfs_balance_metadata(struct btrfs_root *dev_root);
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,
--
1.7.4.4
--
Alexandre Oliva, freedom fighter http://FSFLA.org/~lxoliva/
You must be the change you wish to see in the world. -- Gandhi
Be Free! -- http://FSFLA.org/ FSF Latin America board member
Free Software Evangelist Red Hat Brazil Compiler Engineer
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