Btrfs: Clone file data ioctl
Add a new ioctl to clone file data
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 9948344..c6fae29 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -19,6 +19,7 @@
#include <linux/kernel.h>
#include <linux/bio.h>
#include <linux/buffer_head.h>
+#include <linux/file.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/highmem.h>
@@ -141,7 +142,7 @@
cur_alloc_size = ins.offset;
ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
start, ins.objectid, ins.offset,
- ins.offset);
+ ins.offset, 0);
inode->i_blocks += ins.offset >> 9;
btrfs_check_file(root, inode);
if (num_bytes < cur_alloc_size) {
@@ -1227,7 +1228,7 @@
err = btrfs_insert_file_extent(trans, root,
inode->i_ino,
hole_start, 0, 0,
- hole_size);
+ hole_size, 0);
btrfs_drop_extent_cache(inode, hole_start,
(u64)-1);
btrfs_check_file(root, inode);
@@ -3100,6 +3101,170 @@
return ret;
}
+void dup_item_to_inode(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ struct extent_buffer *leaf,
+ int slot,
+ struct btrfs_key *key,
+ u64 destino)
+{
+ struct btrfs_path *cpath = btrfs_alloc_path();
+ int len = btrfs_item_size_nr(leaf, slot);
+ int dstoff;
+ struct btrfs_key ckey = *key;
+ int ret;
+
+ ckey.objectid = destino;
+ ret = btrfs_insert_empty_item(trans, root, cpath, &ckey, len);
+ dstoff = btrfs_item_ptr_offset(cpath->nodes[0], cpath->slots[0]);
+ copy_extent_buffer(cpath->nodes[0], leaf, dstoff,
+ btrfs_item_ptr_offset(leaf, slot),
+ len);
+ btrfs_release_path(root, cpath);
+}
+
+long btrfs_ioctl_clone(struct file *file, unsigned long src_fd)
+{
+ struct inode *inode = fdentry(file)->d_inode;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct file *src_file;
+ struct inode *src;
+ struct btrfs_trans_handle *trans;
+ int ret;
+ u64 pos;
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ struct extent_buffer *leaf;
+ u32 nritems;
+ int nextret;
+ int slot;
+
+ src_file = fget(src_fd);
+ if (!src_file)
+ return -EBADF;
+ src = src_file->f_dentry->d_inode;
+
+ ret = -EXDEV;
+ if (src->i_sb != inode->i_sb)
+ goto out_fput;
+
+ if (inode < src) {
+ mutex_lock(&inode->i_mutex);
+ mutex_lock(&src->i_mutex);
+ } else {
+ mutex_lock(&src->i_mutex);
+ mutex_lock(&inode->i_mutex);
+ }
+
+ ret = -ENOTEMPTY;
+ if (inode->i_size)
+ goto out_unlock;
+
+ /* do any pending delalloc/csum calc on src, one way or
+ another, and lock file content */
+ while (1) {
+ filemap_write_and_wait(src->i_mapping);
+ lock_extent(&BTRFS_I(src)->io_tree, 0, (u64)-1, GFP_NOFS);
+ if (BTRFS_I(src)->delalloc_bytes == 0)
+ break;
+ unlock_extent(&BTRFS_I(src)->io_tree, 0, (u64)-1, GFP_NOFS);
+ }
+
+ mutex_lock(&root->fs_info->fs_mutex);
+ trans = btrfs_start_transaction(root, 0);
+ path = btrfs_alloc_path();
+ pos = 0;
+ while (1) {
+ ret = btrfs_lookup_file_extent(trans, root, path, src->i_ino,
+ pos, 0);
+ if (ret < 0)
+ goto out;
+ if (ret > 0) {
+ if (path->slots[0] == 0) {
+ ret = 0;
+ goto out;
+ }
+ path->slots[0]--;
+ }
+next_slot:
+ leaf = path->nodes[0];
+ slot = path->slots[0];
+ btrfs_item_key_to_cpu(leaf, &key, slot);
+ nritems = btrfs_header_nritems(leaf);
+
+ if (btrfs_key_type(&key) > BTRFS_CSUM_ITEM_KEY ||
+ key.objectid != src->i_ino)
+ goto out;
+ if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
+ struct btrfs_file_extent_item *extent;
+ int found_type;
+ pos = key.offset;
+ extent = btrfs_item_ptr(leaf, slot,
+ struct btrfs_file_extent_item);
+ found_type = btrfs_file_extent_type(leaf, extent);
+ if (found_type == BTRFS_FILE_EXTENT_REG) {
+ u64 len = btrfs_file_extent_num_bytes(leaf,
+ extent);
+ u64 ds = btrfs_file_extent_disk_bytenr(leaf,
+ extent);
+ u64 dl = btrfs_file_extent_disk_num_bytes(leaf,
+ extent);
+ u64 off = btrfs_file_extent_offset(leaf,
+ extent);
+ btrfs_insert_file_extent(trans, root,
+ inode->i_ino, pos,
+ ds, dl, len, off);
+ /* ds == 0 means there's a hole */
+ if (ds != 0) {
+ btrfs_inc_extent_ref(trans, root,
+ ds, dl,
+ root->root_key.objectid,
+ trans->transid,
+ inode->i_ino, pos);
+ }
+ pos = key.offset + len;
+ } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
+ dup_item_to_inode(trans, root, path, leaf, slot,
+ &key, inode->i_ino);
+ pos = key.offset + btrfs_item_size_nr(leaf,
+ slot);
+ }
+ } else if (btrfs_key_type(&key) == BTRFS_CSUM_ITEM_KEY)
+ dup_item_to_inode(trans, root, path, leaf, slot, &key,
+ inode->i_ino);
+
+ if (slot >= nritems - 1) {
+ nextret = btrfs_next_leaf(root, path);
+ if (nextret)
+ goto out;
+ } else {
+ path->slots[0]++;
+ }
+ goto next_slot;
+ }
+
+out:
+ btrfs_free_path(path);
+ ret = 0;
+
+ inode->i_blocks = src->i_blocks;
+ i_size_write(inode, src->i_size);
+ btrfs_update_inode(trans, root, inode);
+
+ unlock_extent(&BTRFS_I(src)->io_tree, 0, (u64)-1, GFP_NOFS);
+
+ btrfs_end_transaction(trans, root);
+ mutex_unlock(&root->fs_info->fs_mutex);
+
+out_unlock:
+ mutex_unlock(&src->i_mutex);
+ mutex_unlock(&inode->i_mutex);
+out_fput:
+ fput(src_file);
+ return ret;
+}
+
long btrfs_ioctl(struct file *file, unsigned int
cmd, unsigned long arg)
{
@@ -3116,6 +3281,8 @@
return btrfs_ioctl_add_dev(root, (void __user *)arg);
case BTRFS_IOC_BALANCE:
return btrfs_balance(root->fs_info->dev_root);
+ case BTRFS_IOC_CLONE:
+ return btrfs_ioctl_clone(file, arg);
}
return -ENOTTY;