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ioctl.c
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/*
* Copyright (C) 2007 Oracle. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include <linux/kernel.h>
#include <linux/bio.h>
#include <linux/buffer_head.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/fsnotify.h>
#include <linux/pagemap.h>
#include <linux/highmem.h>
#include <linux/time.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/smp_lock.h>
#include <linux/backing-dev.h>
#include <linux/mount.h>
#include <linux/mpage.h>
#include <linux/namei.h>
#include <linux/swap.h>
#include <linux/writeback.h>
#include <linux/statfs.h>
#include <linux/compat.h>
#include <linux/bit_spinlock.h>
#include <linux/security.h>
#include <linux/xattr.h>
#include <linux/vmalloc.h>
#include "compat.h"
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "btrfs_inode.h"
#include "ioctl.h"
#include "print-tree.h"
#include "volumes.h"
#include "locking.h"
static noinline int create_subvol(struct btrfs_root *root,
struct dentry *dentry,
char *name, int namelen)
{
struct btrfs_trans_handle *trans;
struct btrfs_key key;
struct btrfs_root_item root_item;
struct btrfs_inode_item *inode_item;
struct extent_buffer *leaf;
struct btrfs_root *new_root = root;
struct inode *dir;
int ret;
int err;
u64 objectid;
u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
u64 index = 0;
unsigned long nr = 1;
ret = btrfs_check_metadata_free_space(root);
if (ret)
goto fail_commit;
trans = btrfs_start_transaction(root, 1);
BUG_ON(!trans);
ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
0, &objectid);
if (ret)
goto fail;
leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
objectid, trans->transid, 0, 0, 0);
if (IS_ERR(leaf)) {
ret = PTR_ERR(leaf);
goto fail;
}
btrfs_set_header_nritems(leaf, 0);
btrfs_set_header_level(leaf, 0);
btrfs_set_header_bytenr(leaf, leaf->start);
btrfs_set_header_generation(leaf, trans->transid);
btrfs_set_header_owner(leaf, objectid);
write_extent_buffer(leaf, root->fs_info->fsid,
(unsigned long)btrfs_header_fsid(leaf),
BTRFS_FSID_SIZE);
btrfs_mark_buffer_dirty(leaf);
inode_item = &root_item.inode;
memset(inode_item, 0, sizeof(*inode_item));
inode_item->generation = cpu_to_le64(1);
inode_item->size = cpu_to_le64(3);
inode_item->nlink = cpu_to_le32(1);
inode_item->nbytes = cpu_to_le64(root->leafsize);
inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
btrfs_set_root_bytenr(&root_item, leaf->start);
btrfs_set_root_generation(&root_item, trans->transid);
btrfs_set_root_level(&root_item, 0);
btrfs_set_root_refs(&root_item, 1);
btrfs_set_root_used(&root_item, 0);
btrfs_set_root_last_snapshot(&root_item, 0);
memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
root_item.drop_level = 0;
btrfs_tree_unlock(leaf);
free_extent_buffer(leaf);
leaf = NULL;
btrfs_set_root_dirid(&root_item, new_dirid);
key.objectid = objectid;
key.offset = 1;
btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
&root_item);
if (ret)
goto fail;
/*
* insert the directory item
*/
key.offset = (u64)-1;
dir = dentry->d_parent->d_inode;
ret = btrfs_set_inode_index(dir, &index);
BUG_ON(ret);
ret = btrfs_insert_dir_item(trans, root,
name, namelen, dir->i_ino, &key,
BTRFS_FT_DIR, index);
if (ret)
goto fail;
btrfs_i_size_write(dir, dir->i_size + namelen * 2);
ret = btrfs_update_inode(trans, root, dir);
BUG_ON(ret);
/* add the backref first */
ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
objectid, BTRFS_ROOT_BACKREF_KEY,
root->root_key.objectid,
dir->i_ino, index, name, namelen);
BUG_ON(ret);
/* now add the forward ref */
ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
root->root_key.objectid, BTRFS_ROOT_REF_KEY,
objectid,
dir->i_ino, index, name, namelen);
BUG_ON(ret);
ret = btrfs_commit_transaction(trans, root);
if (ret)
goto fail_commit;
new_root = btrfs_read_fs_root_no_name(root->fs_info, &key);
BUG_ON(!new_root);
trans = btrfs_start_transaction(new_root, 1);
BUG_ON(!trans);
ret = btrfs_create_subvol_root(trans, new_root, dentry, new_dirid,
BTRFS_I(dir)->block_group);
if (ret)
goto fail;
fail:
nr = trans->blocks_used;
err = btrfs_commit_transaction(trans, new_root);
if (err && !ret)
ret = err;
fail_commit:
btrfs_btree_balance_dirty(root, nr);
return ret;
}
static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
char *name, int namelen)
{
struct btrfs_pending_snapshot *pending_snapshot;
struct btrfs_trans_handle *trans;
int ret = 0;
int err;
unsigned long nr = 0;
if (!root->ref_cows)
return -EINVAL;
ret = btrfs_check_metadata_free_space(root);
if (ret)
goto fail_unlock;
pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);
if (!pending_snapshot) {
ret = -ENOMEM;
goto fail_unlock;
}
pending_snapshot->name = kmalloc(namelen + 1, GFP_NOFS);
if (!pending_snapshot->name) {
ret = -ENOMEM;
kfree(pending_snapshot);
goto fail_unlock;
}
memcpy(pending_snapshot->name, name, namelen);
pending_snapshot->name[namelen] = '\0';
pending_snapshot->dentry = dentry;
trans = btrfs_start_transaction(root, 1);
BUG_ON(!trans);
pending_snapshot->root = root;
list_add(&pending_snapshot->list,
&trans->transaction->pending_snapshots);
err = btrfs_commit_transaction(trans, root);
fail_unlock:
btrfs_btree_balance_dirty(root, nr);
return ret;
}
/* copy of may_create in fs/namei.c() */
static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
{
if (child->d_inode)
return -EEXIST;
if (IS_DEADDIR(dir))
return -ENOENT;
return inode_permission(dir, MAY_WRITE | MAY_EXEC);
}
/*
* Create a new subvolume below @parent. This is largely modeled after
* sys_mkdirat and vfs_mkdir, but we only do a single component lookup
* inside this filesystem so it's quite a bit simpler.
*/
static noinline int btrfs_mksubvol(struct path *parent, char *name,
int mode, int namelen,
struct btrfs_root *snap_src)
{
struct dentry *dentry;
int error;
mutex_lock_nested(&parent->dentry->d_inode->i_mutex, I_MUTEX_PARENT);
dentry = lookup_one_len(name, parent->dentry, namelen);
error = PTR_ERR(dentry);
if (IS_ERR(dentry))
goto out_unlock;
error = -EEXIST;
if (dentry->d_inode)
goto out_dput;
if (!IS_POSIXACL(parent->dentry->d_inode))
mode &= ~current->fs->umask;
error = mnt_want_write(parent->mnt);
if (error)
goto out_dput;
error = btrfs_may_create(parent->dentry->d_inode, dentry);
if (error)
goto out_drop_write;
/*
* Actually perform the low-level subvolume creation after all
* this VFS fuzz.
*
* Eventually we want to pass in an inode under which we create this
* subvolume, but for now all are under the filesystem root.
*
* Also we should pass on the mode eventually to allow creating new
* subvolume with specific mode bits.
*/
if (snap_src) {
struct dentry *dir = dentry->d_parent;
struct dentry *test = dir->d_parent;
struct btrfs_path *path = btrfs_alloc_path();
int ret;
u64 test_oid;
u64 parent_oid = BTRFS_I(dir->d_inode)->root->root_key.objectid;
test_oid = snap_src->root_key.objectid;
ret = btrfs_find_root_ref(snap_src->fs_info->tree_root,
path, parent_oid, test_oid);
if (ret == 0)
goto create;
btrfs_release_path(snap_src->fs_info->tree_root, path);
/* we need to make sure we aren't creating a directory loop
* by taking a snapshot of something that has our current
* subvol in its directory tree. So, this loops through
* the dentries and checks the forward refs for each subvolume
* to see if is references the subvolume where we are
* placing this new snapshot.
*/
while (1) {
if (!test ||
dir == snap_src->fs_info->sb->s_root ||
test == snap_src->fs_info->sb->s_root ||
test->d_inode->i_sb != snap_src->fs_info->sb) {
break;
}
if (S_ISLNK(test->d_inode->i_mode)) {
printk(KERN_INFO "Btrfs symlink in snapshot "
"path, failed\n");
error = -EMLINK;
btrfs_free_path(path);
goto out_drop_write;
}
test_oid =
BTRFS_I(test->d_inode)->root->root_key.objectid;
ret = btrfs_find_root_ref(snap_src->fs_info->tree_root,
path, test_oid, parent_oid);
if (ret == 0) {
printk(KERN_INFO "Btrfs snapshot creation "
"failed, looping\n");
error = -EMLINK;
btrfs_free_path(path);
goto out_drop_write;
}
btrfs_release_path(snap_src->fs_info->tree_root, path);
test = test->d_parent;
}
create:
btrfs_free_path(path);
error = create_snapshot(snap_src, dentry, name, namelen);
} else {
error = create_subvol(BTRFS_I(parent->dentry->d_inode)->root,
dentry, name, namelen);
}
if (error)
goto out_drop_write;
fsnotify_mkdir(parent->dentry->d_inode, dentry);
out_drop_write:
mnt_drop_write(parent->mnt);
out_dput:
dput(dentry);
out_unlock:
mutex_unlock(&parent->dentry->d_inode->i_mutex);
return error;
}
static int btrfs_defrag_file(struct file *file)
{
struct inode *inode = fdentry(file)->d_inode;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct btrfs_ordered_extent *ordered;
struct page *page;
unsigned long last_index;
unsigned long ra_pages = root->fs_info->bdi.ra_pages;
unsigned long total_read = 0;
u64 page_start;
u64 page_end;
unsigned long i;
int ret;
ret = btrfs_check_data_free_space(root, inode, inode->i_size);
if (ret)
return -ENOSPC;
mutex_lock(&inode->i_mutex);
last_index = inode->i_size >> PAGE_CACHE_SHIFT;
for (i = 0; i <= last_index; i++) {
if (total_read % ra_pages == 0) {
btrfs_force_ra(inode->i_mapping, &file->f_ra, file, i,
min(last_index, i + ra_pages - 1));
}
total_read++;
again:
page = grab_cache_page(inode->i_mapping, i);
if (!page)
goto out_unlock;
if (!PageUptodate(page)) {
btrfs_readpage(NULL, page);
lock_page(page);
if (!PageUptodate(page)) {
unlock_page(page);
page_cache_release(page);
goto out_unlock;
}
}
wait_on_page_writeback(page);
page_start = (u64)page->index << PAGE_CACHE_SHIFT;
page_end = page_start + PAGE_CACHE_SIZE - 1;
lock_extent(io_tree, page_start, page_end, GFP_NOFS);
ordered = btrfs_lookup_ordered_extent(inode, page_start);
if (ordered) {
unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
unlock_page(page);
page_cache_release(page);
btrfs_start_ordered_extent(inode, ordered, 1);
btrfs_put_ordered_extent(ordered);
goto again;
}
set_page_extent_mapped(page);
/*
* this makes sure page_mkwrite is called on the
* page if it is dirtied again later
*/
clear_page_dirty_for_io(page);
btrfs_set_extent_delalloc(inode, page_start, page_end);
unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
set_page_dirty(page);
unlock_page(page);
page_cache_release(page);
balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1);
}
out_unlock:
mutex_unlock(&inode->i_mutex);
return 0;
}
/*
* Called inside transaction, so use GFP_NOFS
*/
static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg)
{
u64 new_size;
u64 old_size;
u64 devid = 1;
struct btrfs_ioctl_vol_args *vol_args;
struct btrfs_trans_handle *trans;
struct btrfs_device *device = NULL;
char *sizestr;
char *devstr = NULL;
int ret = 0;
int namelen;
int mod = 0;
if (root->fs_info->sb->s_flags & MS_RDONLY)
return -EROFS;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
if (!vol_args)
return -ENOMEM;
if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
ret = -EFAULT;
goto out;
}
vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
namelen = strlen(vol_args->name);
mutex_lock(&root->fs_info->volume_mutex);
sizestr = vol_args->name;
devstr = strchr(sizestr, ':');
if (devstr) {
char *end;
sizestr = devstr + 1;
*devstr = '\0';
devstr = vol_args->name;
devid = simple_strtoull(devstr, &end, 10);
printk(KERN_INFO "resizing devid %llu\n", devid);
}
device = btrfs_find_device(root, devid, NULL, NULL);
if (!device) {
printk(KERN_INFO "resizer unable to find device %llu\n", devid);
ret = -EINVAL;
goto out_unlock;
}
if (!strcmp(sizestr, "max"))
new_size = device->bdev->bd_inode->i_size;
else {
if (sizestr[0] == '-') {
mod = -1;
sizestr++;
} else if (sizestr[0] == '+') {
mod = 1;
sizestr++;
}
new_size = btrfs_parse_size(sizestr);
if (new_size == 0) {
ret = -EINVAL;
goto out_unlock;
}
}
old_size = device->total_bytes;
if (mod < 0) {
if (new_size > old_size) {
ret = -EINVAL;
goto out_unlock;
}
new_size = old_size - new_size;
} else if (mod > 0) {
new_size = old_size + new_size;
}
if (new_size < 256 * 1024 * 1024) {
ret = -EINVAL;
goto out_unlock;
}
if (new_size > device->bdev->bd_inode->i_size) {
ret = -EFBIG;
goto out_unlock;
}
do_div(new_size, root->sectorsize);
new_size *= root->sectorsize;
printk(KERN_INFO "new size for %s is %llu\n",
device->name, (unsigned long long)new_size);
if (new_size > old_size) {
trans = btrfs_start_transaction(root, 1);
ret = btrfs_grow_device(trans, device, new_size);
btrfs_commit_transaction(trans, root);
} else {
ret = btrfs_shrink_device(device, new_size);
}
out_unlock:
mutex_unlock(&root->fs_info->volume_mutex);
out:
kfree(vol_args);
return ret;
}
static noinline int btrfs_ioctl_snap_create(struct file *file,
void __user *arg, int subvol)
{
struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
struct btrfs_ioctl_vol_args *vol_args;
struct btrfs_dir_item *di;
struct btrfs_path *path;
struct file *src_file;
u64 root_dirid;
int namelen;
int ret = 0;
if (root->fs_info->sb->s_flags & MS_RDONLY)
return -EROFS;
vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
if (!vol_args)
return -ENOMEM;
if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
ret = -EFAULT;
goto out;
}
vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
namelen = strlen(vol_args->name);
if (strchr(vol_args->name, '/')) {
ret = -EINVAL;
goto out;
}
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto out;
}
root_dirid = root->fs_info->sb->s_root->d_inode->i_ino,
di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root,
path, root_dirid,
vol_args->name, namelen, 0);
btrfs_free_path(path);
if (di && !IS_ERR(di)) {
ret = -EEXIST;
goto out;
}
if (IS_ERR(di)) {
ret = PTR_ERR(di);
goto out;
}
if (subvol) {
ret = btrfs_mksubvol(&file->f_path, vol_args->name,
file->f_path.dentry->d_inode->i_mode,
namelen, NULL);
} else {
struct inode *src_inode;
src_file = fget(vol_args->fd);
if (!src_file) {
ret = -EINVAL;
goto out;
}
src_inode = src_file->f_path.dentry->d_inode;
if (src_inode->i_sb != file->f_path.dentry->d_inode->i_sb) {
printk(KERN_INFO "btrfs: Snapshot src from "
"another FS\n");
ret = -EINVAL;
fput(src_file);
goto out;
}
ret = btrfs_mksubvol(&file->f_path, vol_args->name,
file->f_path.dentry->d_inode->i_mode,
namelen, BTRFS_I(src_inode)->root);
fput(src_file);
}
out:
kfree(vol_args);
return ret;
}
static int btrfs_ioctl_defrag(struct file *file)
{
struct inode *inode = fdentry(file)->d_inode;
struct btrfs_root *root = BTRFS_I(inode)->root;
int ret;
ret = mnt_want_write(file->f_path.mnt);
if (ret)
return ret;
switch (inode->i_mode & S_IFMT) {
case S_IFDIR:
if (!capable(CAP_SYS_ADMIN)) {
ret = -EPERM;
goto out;
}
btrfs_defrag_root(root, 0);
btrfs_defrag_root(root->fs_info->extent_root, 0);
break;
case S_IFREG:
if (!(file->f_mode & FMODE_WRITE)) {
ret = -EINVAL;
goto out;
}
btrfs_defrag_file(file);
break;
}
out:
mnt_drop_write(file->f_path.mnt);
return ret;
}
static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
{
struct btrfs_ioctl_vol_args *vol_args;
int ret;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
if (!vol_args)
return -ENOMEM;
if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
ret = -EFAULT;
goto out;
}
vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
ret = btrfs_init_new_device(root, vol_args->name);
out:
kfree(vol_args);
return ret;
}
static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
{
struct btrfs_ioctl_vol_args *vol_args;
int ret;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (root->fs_info->sb->s_flags & MS_RDONLY)
return -EROFS;
vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
if (!vol_args)
return -ENOMEM;
if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
ret = -EFAULT;
goto out;
}
vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
ret = btrfs_rm_device(root, vol_args->name);
out:
kfree(vol_args);
return ret;
}
static long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
u64 off, u64 olen, u64 destoff)
{
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;
struct btrfs_path *path;
struct extent_buffer *leaf;
char *buf;
struct btrfs_key key;
u32 nritems;
int slot;
int ret;
u64 len = olen;
u64 bs = root->fs_info->sb->s_blocksize;
u64 hint_byte;
/*
* TODO:
* - split compressed inline extents. annoying: we need to
* decompress into destination's address_space (the file offset
* may change, so source mapping won't do), then recompress (or
* otherwise reinsert) a subrange.
* - allow ranges within the same file to be cloned (provided
* they don't overlap)?
*/
/* the destination must be opened for writing */
if (!(file->f_mode & FMODE_WRITE))
return -EINVAL;
ret = mnt_want_write(file->f_path.mnt);
if (ret)
return ret;
src_file = fget(srcfd);
if (!src_file) {
ret = -EBADF;
goto out_drop_write;
}
src = src_file->f_dentry->d_inode;
ret = -EINVAL;
if (src == inode)
goto out_fput;
ret = -EISDIR;
if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
goto out_fput;
ret = -EXDEV;
if (src->i_sb != inode->i_sb || BTRFS_I(src)->root != root)
goto out_fput;
ret = -ENOMEM;
buf = vmalloc(btrfs_level_size(root, 0));
if (!buf)
goto out_fput;
path = btrfs_alloc_path();
if (!path) {
vfree(buf);
goto out_fput;
}
path->reada = 2;
if (inode < src) {
mutex_lock(&inode->i_mutex);
mutex_lock(&src->i_mutex);
} else {
mutex_lock(&src->i_mutex);
mutex_lock(&inode->i_mutex);
}
/* determine range to clone */
ret = -EINVAL;
if (off >= src->i_size || off + len > src->i_size)
goto out_unlock;
if (len == 0)
olen = len = src->i_size - off;
/* if we extend to eof, continue to block boundary */
if (off + len == src->i_size)
len = ((src->i_size + bs-1) & ~(bs-1))
- off;
/* verify the end result is block aligned */
if ((off & (bs-1)) ||
((off + len) & (bs-1)))
goto out_unlock;
/* do any pending delalloc/csum calc on src, one way or
another, and lock file content */
while (1) {
struct btrfs_ordered_extent *ordered;
lock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
ordered = btrfs_lookup_first_ordered_extent(inode, off+len);
if (BTRFS_I(src)->delalloc_bytes == 0 && !ordered)
break;
unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
if (ordered)
btrfs_put_ordered_extent(ordered);
btrfs_wait_ordered_range(src, off, off+len);
}
trans = btrfs_start_transaction(root, 1);
BUG_ON(!trans);
/* punch hole in destination first */
btrfs_drop_extents(trans, root, inode, off, off+len, 0, &hint_byte);
/* clone data */
key.objectid = src->i_ino;
key.type = BTRFS_EXTENT_DATA_KEY;
key.offset = 0;
while (1) {
/*
* note the key will change type as we walk through the
* tree.
*/
ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
if (ret < 0)
goto out;
nritems = btrfs_header_nritems(path->nodes[0]);
if (path->slots[0] >= nritems) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
goto out;
if (ret > 0)
break;
nritems = btrfs_header_nritems(path->nodes[0]);
}
leaf = path->nodes[0];
slot = path->slots[0];
btrfs_item_key_to_cpu(leaf, &key, slot);
if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY ||
key.objectid != src->i_ino)
break;
if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
struct btrfs_file_extent_item *extent;
int type;
u32 size;
struct btrfs_key new_key;
u64 disko = 0, diskl = 0;
u64 datao = 0, datal = 0;
u8 comp;
size = btrfs_item_size_nr(leaf, slot);
read_extent_buffer(leaf, buf,
btrfs_item_ptr_offset(leaf, slot),
size);
extent = btrfs_item_ptr(leaf, slot,
struct btrfs_file_extent_item);
comp = btrfs_file_extent_compression(leaf, extent);
type = btrfs_file_extent_type(leaf, extent);
if (type == BTRFS_FILE_EXTENT_REG) {
disko = btrfs_file_extent_disk_bytenr(leaf,
extent);
diskl = btrfs_file_extent_disk_num_bytes(leaf,
extent);
datao = btrfs_file_extent_offset(leaf, extent);
datal = btrfs_file_extent_num_bytes(leaf,
extent);
} else if (type == BTRFS_FILE_EXTENT_INLINE) {
/* take upper bound, may be compressed */
datal = btrfs_file_extent_ram_bytes(leaf,
extent);
}
btrfs_release_path(root, path);
if (key.offset + datal < off ||
key.offset >= off+len)
goto next;
memcpy(&new_key, &key, sizeof(new_key));
new_key.objectid = inode->i_ino;
new_key.offset = key.offset + destoff - off;
if (type == BTRFS_FILE_EXTENT_REG) {
ret = btrfs_insert_empty_item(trans, root, path,
&new_key, size);
if (ret)
goto out;
leaf = path->nodes[0];
slot = path->slots[0];
write_extent_buffer(leaf, buf,
btrfs_item_ptr_offset(leaf, slot),
size);
extent = btrfs_item_ptr(leaf, slot,
struct btrfs_file_extent_item);
if (off > key.offset) {
datao += off - key.offset;
datal -= off - key.offset;
}
if (key.offset + datao + datal + key.offset >
off + len)
datal = off + len - key.offset - datao;
/* disko == 0 means it's a hole */
if (!disko)
datao = 0;
btrfs_set_file_extent_offset(leaf, extent,
datao);
btrfs_set_file_extent_num_bytes(leaf, extent,
datal);
if (disko) {
inode_add_bytes(inode, datal);
ret = btrfs_inc_extent_ref(trans, root,
disko, diskl, leaf->start,
root->root_key.objectid,
trans->transid,
inode->i_ino);
BUG_ON(ret);
}
} else if (type == BTRFS_FILE_EXTENT_INLINE) {
u64 skip = 0;
u64 trim = 0;
if (off > key.offset) {
skip = off - key.offset;
new_key.offset += skip;
}
if (key.offset + datal > off+len)
trim = key.offset + datal - (off+len);
if (comp && (skip || trim)) {
ret = -EINVAL;
goto out;
}
size -= skip + trim;
datal -= skip + trim;
ret = btrfs_insert_empty_item(trans, root, path,
&new_key, size);
if (ret)
goto out;
if (skip) {
u32 start =
btrfs_file_extent_calc_inline_size(0);
memmove(buf+start, buf+start+skip,
datal);
}
leaf = path->nodes[0];
slot = path->slots[0];
write_extent_buffer(leaf, buf,
btrfs_item_ptr_offset(leaf, slot),
size);
inode_add_bytes(inode, datal);
}
btrfs_mark_buffer_dirty(leaf);
}
next:
btrfs_release_path(root, path);
key.offset++;
}
ret = 0;
out:
btrfs_release_path(root, path);
if (ret == 0) {
inode->i_mtime = inode->i_ctime = CURRENT_TIME;
if (destoff + olen > inode->i_size)
btrfs_i_size_write(inode, destoff + olen);
BTRFS_I(inode)->flags = BTRFS_I(src)->flags;
ret = btrfs_update_inode(trans, root, inode);
}
btrfs_end_transaction(trans, root);