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OpenCloudOS-Kernel/fs/btrfs/inode.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/module.h>
#include <linux/buffer_head.h>
#include <linux/fs.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/mpage.h>
#include <linux/swap.h>
#include <linux/writeback.h>
#include <linux/statfs.h>
#include <linux/compat.h>
#include <linux/bit_spinlock.h>
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "btrfs_inode.h"
#include "ioctl.h"
#include "print-tree.h"
struct btrfs_iget_args {
u64 ino;
struct btrfs_root *root;
};
static struct inode_operations btrfs_dir_inode_operations;
static struct inode_operations btrfs_symlink_inode_operations;
static struct inode_operations btrfs_dir_ro_inode_operations;
static struct inode_operations btrfs_file_inode_operations;
static struct address_space_operations btrfs_aops;
static struct address_space_operations btrfs_symlink_aops;
static struct file_operations btrfs_dir_file_operations;
static struct kmem_cache *btrfs_inode_cachep;
struct kmem_cache *btrfs_trans_handle_cachep;
struct kmem_cache *btrfs_transaction_cachep;
struct kmem_cache *btrfs_bit_radix_cachep;
struct kmem_cache *btrfs_path_cachep;
#define S_SHIFT 12
static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
[S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
[S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
[S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
[S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
[S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
[S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
[S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
};
void btrfs_read_locked_inode(struct inode *inode)
{
struct btrfs_path *path;
struct btrfs_inode_item *inode_item;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_key location;
u64 alloc_group_block;
int ret;
path = btrfs_alloc_path();
BUG_ON(!path);
mutex_lock(&root->fs_info->fs_mutex);
memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
if (ret) {
btrfs_free_path(path);
goto make_bad;
}
inode_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
path->slots[0],
struct btrfs_inode_item);
inode->i_mode = btrfs_inode_mode(inode_item);
inode->i_nlink = btrfs_inode_nlink(inode_item);
inode->i_uid = btrfs_inode_uid(inode_item);
inode->i_gid = btrfs_inode_gid(inode_item);
inode->i_size = btrfs_inode_size(inode_item);
inode->i_atime.tv_sec = btrfs_timespec_sec(&inode_item->atime);
inode->i_atime.tv_nsec = btrfs_timespec_nsec(&inode_item->atime);
inode->i_mtime.tv_sec = btrfs_timespec_sec(&inode_item->mtime);
inode->i_mtime.tv_nsec = btrfs_timespec_nsec(&inode_item->mtime);
inode->i_ctime.tv_sec = btrfs_timespec_sec(&inode_item->ctime);
inode->i_ctime.tv_nsec = btrfs_timespec_nsec(&inode_item->ctime);
inode->i_blocks = btrfs_inode_nblocks(inode_item);
inode->i_generation = btrfs_inode_generation(inode_item);
alloc_group_block = btrfs_inode_block_group(inode_item);
BTRFS_I(inode)->block_group = btrfs_lookup_block_group(root->fs_info,
alloc_group_block);
btrfs_free_path(path);
inode_item = NULL;
mutex_unlock(&root->fs_info->fs_mutex);
switch (inode->i_mode & S_IFMT) {
#if 0
default:
init_special_inode(inode, inode->i_mode,
btrfs_inode_rdev(inode_item));
break;
#endif
case S_IFREG:
inode->i_mapping->a_ops = &btrfs_aops;
inode->i_fop = &btrfs_file_operations;
inode->i_op = &btrfs_file_inode_operations;
break;
case S_IFDIR:
inode->i_fop = &btrfs_dir_file_operations;
if (root == root->fs_info->tree_root)
inode->i_op = &btrfs_dir_ro_inode_operations;
else
inode->i_op = &btrfs_dir_inode_operations;
break;
case S_IFLNK:
inode->i_op = &btrfs_symlink_inode_operations;
inode->i_mapping->a_ops = &btrfs_symlink_aops;
break;
}
return;
make_bad:
btrfs_release_path(root, path);
btrfs_free_path(path);
mutex_unlock(&root->fs_info->fs_mutex);
make_bad_inode(inode);
}
static void fill_inode_item(struct btrfs_inode_item *item,
struct inode *inode)
{
btrfs_set_inode_uid(item, inode->i_uid);
btrfs_set_inode_gid(item, inode->i_gid);
btrfs_set_inode_size(item, inode->i_size);
btrfs_set_inode_mode(item, inode->i_mode);
btrfs_set_inode_nlink(item, inode->i_nlink);
btrfs_set_timespec_sec(&item->atime, inode->i_atime.tv_sec);
btrfs_set_timespec_nsec(&item->atime, inode->i_atime.tv_nsec);
btrfs_set_timespec_sec(&item->mtime, inode->i_mtime.tv_sec);
btrfs_set_timespec_nsec(&item->mtime, inode->i_mtime.tv_nsec);
btrfs_set_timespec_sec(&item->ctime, inode->i_ctime.tv_sec);
btrfs_set_timespec_nsec(&item->ctime, inode->i_ctime.tv_nsec);
btrfs_set_inode_nblocks(item, inode->i_blocks);
btrfs_set_inode_generation(item, inode->i_generation);
btrfs_set_inode_block_group(item,
BTRFS_I(inode)->block_group->key.objectid);
}
static int btrfs_update_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *inode)
{
struct btrfs_inode_item *inode_item;
struct btrfs_path *path;
int ret;
path = btrfs_alloc_path();
BUG_ON(!path);
ret = btrfs_lookup_inode(trans, root, path,
&BTRFS_I(inode)->location, 1);
if (ret) {
if (ret > 0)
ret = -ENOENT;
goto failed;
}
inode_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
path->slots[0],
struct btrfs_inode_item);
fill_inode_item(inode_item, inode);
btrfs_mark_buffer_dirty(path->nodes[0]);
ret = 0;
failed:
btrfs_release_path(root, path);
btrfs_free_path(path);
return ret;
}
static int btrfs_unlink_trans(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *dir,
struct dentry *dentry)
{
struct btrfs_path *path;
const char *name = dentry->d_name.name;
int name_len = dentry->d_name.len;
int ret = 0;
u64 objectid;
struct btrfs_dir_item *di;
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto err;
}
di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
name, name_len, -1);
if (IS_ERR(di)) {
ret = PTR_ERR(di);
goto err;
}
if (!di) {
ret = -ENOENT;
goto err;
}
objectid = btrfs_disk_key_objectid(&di->location);
ret = btrfs_delete_one_dir_name(trans, root, path, di);
if (ret)
goto err;
btrfs_release_path(root, path);
di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
objectid, name, name_len, -1);
if (IS_ERR(di)) {
ret = PTR_ERR(di);
goto err;
}
if (!di) {
ret = -ENOENT;
goto err;
}
ret = btrfs_delete_one_dir_name(trans, root, path, di);
dentry->d_inode->i_ctime = dir->i_ctime;
err:
btrfs_free_path(path);
if (!ret) {
dir->i_size -= name_len * 2;
dir->i_mtime = dir->i_ctime = CURRENT_TIME;
btrfs_update_inode(trans, root, dir);
drop_nlink(dentry->d_inode);
ret = btrfs_update_inode(trans, root, dentry->d_inode);
dir->i_sb->s_dirt = 1;
}
return ret;
}
static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
{
struct btrfs_root *root;
struct btrfs_trans_handle *trans;
int ret;
root = BTRFS_I(dir)->root;
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, dir);
ret = btrfs_unlink_trans(trans, root, dir, dentry);
btrfs_end_transaction(trans, root);
mutex_unlock(&root->fs_info->fs_mutex);
btrfs_btree_balance_dirty(root);
return ret;
}
static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
{
struct inode *inode = dentry->d_inode;
int err;
int ret;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_path *path;
struct btrfs_key key;
struct btrfs_trans_handle *trans;
struct btrfs_key found_key;
int found_type;
struct btrfs_leaf *leaf;
char *goodnames = "..";
path = btrfs_alloc_path();
BUG_ON(!path);
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, dir);
key.objectid = inode->i_ino;
key.offset = (u64)-1;
key.flags = (u32)-1;
while(1) {
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret < 0) {
err = ret;
goto out;
}
BUG_ON(ret == 0);
if (path->slots[0] == 0) {
err = -ENOENT;
goto out;
}
path->slots[0]--;
leaf = btrfs_buffer_leaf(path->nodes[0]);
btrfs_disk_key_to_cpu(&found_key,
&leaf->items[path->slots[0]].key);
found_type = btrfs_key_type(&found_key);
if (found_key.objectid != inode->i_ino) {
err = -ENOENT;
goto out;
}
if ((found_type != BTRFS_DIR_ITEM_KEY &&
found_type != BTRFS_DIR_INDEX_KEY) ||
(!btrfs_match_dir_item_name(root, path, goodnames, 2) &&
!btrfs_match_dir_item_name(root, path, goodnames, 1))) {
err = -ENOTEMPTY;
goto out;
}
ret = btrfs_del_item(trans, root, path);
BUG_ON(ret);
if (found_type == BTRFS_DIR_ITEM_KEY && found_key.offset == 1)
break;
btrfs_release_path(root, path);
}
ret = 0;
btrfs_release_path(root, path);
/* now the directory is empty */
err = btrfs_unlink_trans(trans, root, dir, dentry);
if (!err) {
inode->i_size = 0;
}
out:
btrfs_release_path(root, path);
btrfs_free_path(path);
mutex_unlock(&root->fs_info->fs_mutex);
ret = btrfs_end_transaction(trans, root);
btrfs_btree_balance_dirty(root);
if (ret && !err)
err = ret;
return err;
}
static int btrfs_free_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *inode)
{
struct btrfs_path *path;
int ret;
clear_inode(inode);
path = btrfs_alloc_path();
BUG_ON(!path);
ret = btrfs_lookup_inode(trans, root, path,
&BTRFS_I(inode)->location, -1);
if (ret > 0)
ret = -ENOENT;
if (!ret)
ret = btrfs_del_item(trans, root, path);
btrfs_free_path(path);
return ret;
}
/*
* truncates go from a high offset to a low offset. So, walk
* from hi to lo in the node and issue readas. Stop when you find
* keys from a different objectid
*/
static void reada_truncate(struct btrfs_root *root, struct btrfs_path *path,
u64 objectid)
{
struct btrfs_node *node;
int i;
int nritems;
u64 item_objectid;
u64 blocknr;
int slot;
int ret;
if (!path->nodes[1])
return;
node = btrfs_buffer_node(path->nodes[1]);
slot = path->slots[1];
if (slot == 0)
return;
nritems = btrfs_header_nritems(&node->header);
for (i = slot - 1; i >= 0; i--) {
item_objectid = btrfs_disk_key_objectid(&node->ptrs[i].key);
if (item_objectid != objectid)
break;
blocknr = btrfs_node_blockptr(node, i);
ret = readahead_tree_block(root, blocknr);
if (ret)
break;
}
}
/*
* this can truncate away extent items, csum items and directory items.
* It starts at a high offset and removes keys until it can't find
* any higher than i_size.
*
* csum items that cross the new i_size are truncated to the new size
* as well.
*/
static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *inode)
{
int ret;
struct btrfs_path *path;
struct btrfs_key key;
struct btrfs_disk_key *found_key;
u32 found_type;
struct btrfs_leaf *leaf;
struct btrfs_file_extent_item *fi;
u64 extent_start = 0;
u64 extent_num_blocks = 0;
u64 item_end = 0;
int found_extent;
int del_item;
path = btrfs_alloc_path();
BUG_ON(!path);
/* FIXME, add redo link to tree so we don't leak on crash */
key.objectid = inode->i_ino;
key.offset = (u64)-1;
key.flags = (u32)-1;
while(1) {
btrfs_init_path(path);
fi = NULL;
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret < 0) {
goto error;
}
if (ret > 0) {
BUG_ON(path->slots[0] == 0);
path->slots[0]--;
}
reada_truncate(root, path, inode->i_ino);
leaf = btrfs_buffer_leaf(path->nodes[0]);
found_key = &leaf->items[path->slots[0]].key;
found_type = btrfs_disk_key_type(found_key);
if (btrfs_disk_key_objectid(found_key) != inode->i_ino)
break;
if (found_type != BTRFS_CSUM_ITEM_KEY &&
found_type != BTRFS_DIR_ITEM_KEY &&
found_type != BTRFS_DIR_INDEX_KEY &&
found_type != BTRFS_EXTENT_DATA_KEY)
break;
item_end = btrfs_disk_key_offset(found_key);
if (found_type == BTRFS_EXTENT_DATA_KEY) {
fi = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
path->slots[0],
struct btrfs_file_extent_item);
if (btrfs_file_extent_type(fi) !=
BTRFS_FILE_EXTENT_INLINE) {
item_end += btrfs_file_extent_num_blocks(fi) <<
inode->i_blkbits;
}
}
if (found_type == BTRFS_CSUM_ITEM_KEY) {
ret = btrfs_csum_truncate(trans, root, path,
inode->i_size);
BUG_ON(ret);
}
if (item_end < inode->i_size) {
if (found_type) {
btrfs_set_key_type(&key, found_type - 1);
continue;
}
break;
}
if (btrfs_disk_key_offset(found_key) >= inode->i_size)
del_item = 1;
else
del_item = 0;
found_extent = 0;
/* FIXME, shrink the extent if the ref count is only 1 */
if (found_type == BTRFS_EXTENT_DATA_KEY &&
btrfs_file_extent_type(fi) !=
BTRFS_FILE_EXTENT_INLINE) {
u64 num_dec;
if (!del_item) {
u64 orig_num_blocks =
btrfs_file_extent_num_blocks(fi);
extent_num_blocks = inode->i_size -
btrfs_disk_key_offset(found_key) +
root->blocksize - 1;
extent_num_blocks >>= inode->i_blkbits;
btrfs_set_file_extent_num_blocks(fi,
extent_num_blocks);
inode->i_blocks -= (orig_num_blocks -
extent_num_blocks) << 3;
mark_buffer_dirty(path->nodes[0]);
} else {
extent_start =
btrfs_file_extent_disk_blocknr(fi);
extent_num_blocks =
btrfs_file_extent_disk_num_blocks(fi);
/* FIXME blocksize != 4096 */
num_dec = btrfs_file_extent_num_blocks(fi) << 3;
if (extent_start != 0) {
found_extent = 1;
inode->i_blocks -= num_dec;
}
}
}
if (del_item) {
ret = btrfs_del_item(trans, root, path);
if (ret)
goto error;
} else {
break;
}
btrfs_release_path(root, path);
if (found_extent) {
ret = btrfs_free_extent(trans, root, extent_start,
extent_num_blocks, 0);
BUG_ON(ret);
}
}
ret = 0;
error:
btrfs_release_path(root, path);
btrfs_free_path(path);
inode->i_sb->s_dirt = 1;
return ret;
}
/*
* taken from block_truncate_page, but does cow as it zeros out
* any bytes left in the last page in the file.
*/
static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
{
struct inode *inode = mapping->host;
unsigned blocksize = 1 << inode->i_blkbits;
pgoff_t index = from >> PAGE_CACHE_SHIFT;
unsigned offset = from & (PAGE_CACHE_SIZE-1);
struct page *page;
char *kaddr;
int ret = 0;
struct btrfs_root *root = BTRFS_I(inode)->root;
u64 alloc_hint = 0;
struct btrfs_key ins;
struct btrfs_trans_handle *trans;
if ((offset & (blocksize - 1)) == 0)
goto out;
ret = -ENOMEM;
page = grab_cache_page(mapping, index);
if (!page)
goto out;
if (!PageUptodate(page)) {
ret = btrfs_readpage(NULL, page);
lock_page(page);
if (!PageUptodate(page)) {
ret = -EIO;
goto out;
}
}
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, inode);
ret = btrfs_drop_extents(trans, root, inode,
page->index << PAGE_CACHE_SHIFT,
(page->index + 1) << PAGE_CACHE_SHIFT,
&alloc_hint);
if (ret)
goto out;
ret = btrfs_alloc_extent(trans, root, inode->i_ino, 1,
alloc_hint, (u64)-1, &ins, 1);
if (ret)
goto out;
ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
page->index << PAGE_CACHE_SHIFT,
ins.objectid, 1, 1);
if (ret)
goto out;
SetPageChecked(page);
kaddr = kmap(page);
memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset);
flush_dcache_page(page);
ret = btrfs_csum_file_block(trans, root, inode->i_ino,
page->index << PAGE_CACHE_SHIFT,
kaddr, PAGE_CACHE_SIZE);
kunmap(page);
btrfs_end_transaction(trans, root);
mutex_unlock(&root->fs_info->fs_mutex);
set_page_dirty(page);
unlock_page(page);
page_cache_release(page);
out:
return ret;
}
static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
{
struct inode *inode = dentry->d_inode;
int err;
err = inode_change_ok(inode, attr);
if (err)
return err;
if (S_ISREG(inode->i_mode) &&
attr->ia_valid & ATTR_SIZE && attr->ia_size > inode->i_size) {
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(inode)->root;
u64 mask = root->blocksize - 1;
u64 pos = (inode->i_size + mask) & ~mask;
u64 hole_size;
if (attr->ia_size <= pos)
goto out;
btrfs_truncate_page(inode->i_mapping, inode->i_size);
hole_size = (attr->ia_size - pos + mask) & ~mask;
hole_size >>= inode->i_blkbits;
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, inode);
err = btrfs_insert_file_extent(trans, root, inode->i_ino,
pos, 0, 0, hole_size);
btrfs_end_transaction(trans, root);
mutex_unlock(&root->fs_info->fs_mutex);
if (err)
return err;
}
out:
err = inode_setattr(inode, attr);
return err;
}
void btrfs_delete_inode(struct inode *inode)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(inode)->root;
int ret;
truncate_inode_pages(&inode->i_data, 0);
if (is_bad_inode(inode)) {
goto no_delete;
}
inode->i_size = 0;
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, inode);
ret = btrfs_truncate_in_trans(trans, root, inode);
if (ret)
goto no_delete_lock;
ret = btrfs_free_inode(trans, root, inode);
if (ret)
goto no_delete_lock;
btrfs_end_transaction(trans, root);
mutex_unlock(&root->fs_info->fs_mutex);
btrfs_btree_balance_dirty(root);
return;
no_delete_lock:
btrfs_end_transaction(trans, root);
mutex_unlock(&root->fs_info->fs_mutex);
btrfs_btree_balance_dirty(root);
no_delete:
clear_inode(inode);
}
/*
* this returns the key found in the dir entry in the location pointer.
* If no dir entries were found, location->objectid is 0.
*/
static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
struct btrfs_key *location)
{
const char *name = dentry->d_name.name;
int namelen = dentry->d_name.len;
struct btrfs_dir_item *di;
struct btrfs_path *path;
struct btrfs_root *root = BTRFS_I(dir)->root;
int ret;
path = btrfs_alloc_path();
BUG_ON(!path);
di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
namelen, 0);
if (!di || IS_ERR(di)) {
location->objectid = 0;
ret = 0;
goto out;
}
btrfs_disk_key_to_cpu(location, &di->location);
out:
btrfs_release_path(root, path);
btrfs_free_path(path);
return ret;
}
/*
* when we hit a tree root in a directory, the btrfs part of the inode
* needs to be changed to reflect the root directory of the tree root. This
* is kind of like crossing a mount point.
*/
static int fixup_tree_root_location(struct btrfs_root *root,
struct btrfs_key *location,
struct btrfs_root **sub_root)
{
struct btrfs_path *path;
struct btrfs_root_item *ri;
if (btrfs_key_type(location) != BTRFS_ROOT_ITEM_KEY)
return 0;
if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
return 0;
path = btrfs_alloc_path();
BUG_ON(!path);
mutex_lock(&root->fs_info->fs_mutex);
*sub_root = btrfs_read_fs_root(root->fs_info, location);
if (IS_ERR(*sub_root))
return PTR_ERR(*sub_root);
ri = &(*sub_root)->root_item;
location->objectid = btrfs_root_dirid(ri);
location->flags = 0;
btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
location->offset = 0;
btrfs_free_path(path);
mutex_unlock(&root->fs_info->fs_mutex);
return 0;
}
static int btrfs_init_locked_inode(struct inode *inode, void *p)
{
struct btrfs_iget_args *args = p;
inode->i_ino = args->ino;
BTRFS_I(inode)->root = args->root;
return 0;
}
static int btrfs_find_actor(struct inode *inode, void *opaque)
{
struct btrfs_iget_args *args = opaque;
return (args->ino == inode->i_ino &&
args->root == BTRFS_I(inode)->root);
}
struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid,
struct btrfs_root *root)
{
struct inode *inode;
struct btrfs_iget_args args;
args.ino = objectid;
args.root = root;
inode = iget5_locked(s, objectid, btrfs_find_actor,
btrfs_init_locked_inode,
(void *)&args);
return inode;
}
static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
struct nameidata *nd)
{
struct inode * inode;
struct btrfs_inode *bi = BTRFS_I(dir);
struct btrfs_root *root = bi->root;
struct btrfs_root *sub_root = root;
struct btrfs_key location;
int ret;
if (dentry->d_name.len > BTRFS_NAME_LEN)
return ERR_PTR(-ENAMETOOLONG);
mutex_lock(&root->fs_info->fs_mutex);
ret = btrfs_inode_by_name(dir, dentry, &location);
mutex_unlock(&root->fs_info->fs_mutex);
if (ret < 0)
return ERR_PTR(ret);
inode = NULL;
if (location.objectid) {
ret = fixup_tree_root_location(root, &location, &sub_root);
if (ret < 0)
return ERR_PTR(ret);
if (ret > 0)
return ERR_PTR(-ENOENT);
inode = btrfs_iget_locked(dir->i_sb, location.objectid,
sub_root);
if (!inode)
return ERR_PTR(-EACCES);
if (inode->i_state & I_NEW) {
/* the inode and parent dir are two different roots */
if (sub_root != root) {
igrab(inode);
sub_root->inode = inode;
}
BTRFS_I(inode)->root = sub_root;
memcpy(&BTRFS_I(inode)->location, &location,
sizeof(location));
btrfs_read_locked_inode(inode);
unlock_new_inode(inode);
}
}
return d_splice_alias(inode, dentry);
}
/*
* readahead one full node of leaves as long as their keys include
* the objectid supplied
*/
static void reada_leaves(struct btrfs_root *root, struct btrfs_path *path,
u64 objectid)
{
struct btrfs_node *node;
int i;
u32 nritems;
u64 item_objectid;
u64 blocknr;
int slot;
int ret;
if (!path->nodes[1])
return;
node = btrfs_buffer_node(path->nodes[1]);
slot = path->slots[1];
nritems = btrfs_header_nritems(&node->header);
for (i = slot + 1; i < nritems; i++) {
item_objectid = btrfs_disk_key_objectid(&node->ptrs[i].key);
if (item_objectid != objectid)
break;
blocknr = btrfs_node_blockptr(node, i);
ret = readahead_tree_block(root, blocknr);
if (ret)
break;
}
}
static unsigned char btrfs_filetype_table[] = {
DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
};
static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
struct inode *inode = filp->f_path.dentry->d_inode;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_item *item;
struct btrfs_dir_item *di;
struct btrfs_key key;
struct btrfs_path *path;
int ret;
u32 nritems;
struct btrfs_leaf *leaf;
int slot;
int advance;
unsigned char d_type;
int over = 0;
u32 di_cur;
u32 di_total;
u32 di_len;
int key_type = BTRFS_DIR_INDEX_KEY;
/* FIXME, use a real flag for deciding about the key type */
if (root->fs_info->tree_root == root)
key_type = BTRFS_DIR_ITEM_KEY;
mutex_lock(&root->fs_info->fs_mutex);
key.objectid = inode->i_ino;
key.flags = 0;
btrfs_set_key_type(&key, key_type);
key.offset = filp->f_pos;
path = btrfs_alloc_path();
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto err;
advance = 0;
reada_leaves(root, path, inode->i_ino);
while(1) {
leaf = btrfs_buffer_leaf(path->nodes[0]);
nritems = btrfs_header_nritems(&leaf->header);
slot = path->slots[0];
if (advance || slot >= nritems) {
if (slot >= nritems -1) {
reada_leaves(root, path, inode->i_ino);
ret = btrfs_next_leaf(root, path);
if (ret)
break;
leaf = btrfs_buffer_leaf(path->nodes[0]);
nritems = btrfs_header_nritems(&leaf->header);
slot = path->slots[0];
} else {
slot++;
path->slots[0]++;
}
}
advance = 1;
item = leaf->items + slot;
if (btrfs_disk_key_objectid(&item->key) != key.objectid)
break;
if (btrfs_disk_key_type(&item->key) != key_type)
break;
if (btrfs_disk_key_offset(&item->key) < filp->f_pos)
continue;
filp->f_pos = btrfs_disk_key_offset(&item->key);
advance = 1;
di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
di_cur = 0;
di_total = btrfs_item_size(leaf->items + slot);
while(di_cur < di_total) {
d_type = btrfs_filetype_table[btrfs_dir_type(di)];
over = filldir(dirent, (const char *)(di + 1),
btrfs_dir_name_len(di),
btrfs_disk_key_offset(&item->key),
btrfs_disk_key_objectid(&di->location),
d_type);
if (over)
goto nopos;
di_len = btrfs_dir_name_len(di) + sizeof(*di);
di_cur += di_len;
di = (struct btrfs_dir_item *)((char *)di + di_len);
}
}
filp->f_pos++;
nopos:
ret = 0;
err:
btrfs_release_path(root, path);
btrfs_free_path(path);
mutex_unlock(&root->fs_info->fs_mutex);
return ret;
}
int btrfs_write_inode(struct inode *inode, int wait)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans;
int ret = 0;
if (wait) {
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, inode);
ret = btrfs_commit_transaction(trans, root);
mutex_unlock(&root->fs_info->fs_mutex);
}
return ret;
}
/*
* This is somewhat expensive, updating the tree every time the
* inode changes. But, it is most likely to find the inode in cache.
* FIXME, needs more benchmarking...there are no reasons other than performance
* to keep or drop this code.
*/
void btrfs_dirty_inode(struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans;
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, inode);
btrfs_update_inode(trans, root, inode);
btrfs_end_transaction(trans, root);
mutex_unlock(&root->fs_info->fs_mutex);
}
static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 objectid,
struct btrfs_block_group_cache *group,
int mode)
{
struct inode *inode;
struct btrfs_inode_item inode_item;
struct btrfs_key *location;
int ret;
int owner;
inode = new_inode(root->fs_info->sb);
if (!inode)
return ERR_PTR(-ENOMEM);
BTRFS_I(inode)->root = root;
if (mode & S_IFDIR)
owner = 0;
else
owner = 1;
group = btrfs_find_block_group(root, group, 0, 0, owner);
BTRFS_I(inode)->block_group = group;
inode->i_uid = current->fsuid;
inode->i_gid = current->fsgid;
inode->i_mode = mode;
inode->i_ino = objectid;
inode->i_blocks = 0;
inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
fill_inode_item(&inode_item, inode);
location = &BTRFS_I(inode)->location;
location->objectid = objectid;
location->flags = 0;
location->offset = 0;
btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
ret = btrfs_insert_inode(trans, root, objectid, &inode_item);
if (ret)
return ERR_PTR(ret);
insert_inode_hash(inode);
return inode;
}
static inline u8 btrfs_inode_type(struct inode *inode)
{
return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
}
static int btrfs_add_link(struct btrfs_trans_handle *trans,
struct dentry *dentry, struct inode *inode)
{
int ret;
struct btrfs_key key;
struct btrfs_root *root = BTRFS_I(dentry->d_parent->d_inode)->root;
struct inode *parent_inode;
key.objectid = inode->i_ino;
key.flags = 0;
btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
key.offset = 0;
ret = btrfs_insert_dir_item(trans, root,
dentry->d_name.name, dentry->d_name.len,
dentry->d_parent->d_inode->i_ino,
&key, btrfs_inode_type(inode));
if (ret == 0) {
parent_inode = dentry->d_parent->d_inode;
parent_inode->i_size += dentry->d_name.len * 2;
parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
ret = btrfs_update_inode(trans, root,
dentry->d_parent->d_inode);
}
return ret;
}
static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
struct dentry *dentry, struct inode *inode)
{
int err = btrfs_add_link(trans, dentry, inode);
if (!err) {
d_instantiate(dentry, inode);
return 0;
}
if (err > 0)
err = -EEXIST;
return err;
}
static int btrfs_create(struct inode *dir, struct dentry *dentry,
int mode, struct nameidata *nd)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct inode *inode;
int err;
int drop_inode = 0;
u64 objectid;
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, dir);
err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
if (err) {
err = -ENOSPC;
goto out_unlock;
}
inode = btrfs_new_inode(trans, root, objectid,
BTRFS_I(dir)->block_group, mode);
err = PTR_ERR(inode);
if (IS_ERR(inode))
goto out_unlock;
btrfs_set_trans_block_group(trans, inode);
err = btrfs_add_nondir(trans, dentry, inode);
if (err)
drop_inode = 1;
else {
inode->i_mapping->a_ops = &btrfs_aops;
inode->i_fop = &btrfs_file_operations;
inode->i_op = &btrfs_file_inode_operations;
}
dir->i_sb->s_dirt = 1;
btrfs_update_inode_block_group(trans, inode);
btrfs_update_inode_block_group(trans, dir);
out_unlock:
btrfs_end_transaction(trans, root);
mutex_unlock(&root->fs_info->fs_mutex);
if (drop_inode) {
inode_dec_link_count(inode);
iput(inode);
}
btrfs_btree_balance_dirty(root);
return err;
}
static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
struct dentry *dentry)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct inode *inode = old_dentry->d_inode;
int err;
int drop_inode = 0;
if (inode->i_nlink == 0)
return -ENOENT;
inc_nlink(inode);
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, dir);
atomic_inc(&inode->i_count);
err = btrfs_add_nondir(trans, dentry, inode);
if (err)
drop_inode = 1;
dir->i_sb->s_dirt = 1;
btrfs_update_inode_block_group(trans, dir);
err = btrfs_update_inode(trans, root, inode);
if (err)
drop_inode = 1;
btrfs_end_transaction(trans, root);
mutex_unlock(&root->fs_info->fs_mutex);
if (drop_inode) {
inode_dec_link_count(inode);
iput(inode);
}
btrfs_btree_balance_dirty(root);
return err;
}
static int btrfs_make_empty_dir(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 objectid, u64 dirid)
{
int ret;
char buf[2];
struct btrfs_key key;
buf[0] = '.';
buf[1] = '.';
key.objectid = objectid;
key.offset = 0;
key.flags = 0;
btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
ret = btrfs_insert_dir_item(trans, root, buf, 1, objectid,
&key, BTRFS_FT_DIR);
if (ret)
goto error;
key.objectid = dirid;
ret = btrfs_insert_dir_item(trans, root, buf, 2, objectid,
&key, BTRFS_FT_DIR);
if (ret)
goto error;
error:
return ret;
}
static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
{
struct inode *inode;
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(dir)->root;
int err = 0;
int drop_on_err = 0;
u64 objectid;
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, dir);
if (IS_ERR(trans)) {
err = PTR_ERR(trans);
goto out_unlock;
}
err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
if (err) {
err = -ENOSPC;
goto out_unlock;
}
inode = btrfs_new_inode(trans, root, objectid,
BTRFS_I(dir)->block_group, S_IFDIR | mode);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto out_fail;
}
drop_on_err = 1;
inode->i_op = &btrfs_dir_inode_operations;
inode->i_fop = &btrfs_dir_file_operations;
btrfs_set_trans_block_group(trans, inode);
err = btrfs_make_empty_dir(trans, root, inode->i_ino, dir->i_ino);
if (err)
goto out_fail;
inode->i_size = 6;
err = btrfs_update_inode(trans, root, inode);
if (err)
goto out_fail;
err = btrfs_add_link(trans, dentry, inode);
if (err)
goto out_fail;
d_instantiate(dentry, inode);
drop_on_err = 0;
dir->i_sb->s_dirt = 1;
btrfs_update_inode_block_group(trans, inode);
btrfs_update_inode_block_group(trans, dir);
out_fail:
btrfs_end_transaction(trans, root);
out_unlock:
mutex_unlock(&root->fs_info->fs_mutex);
if (drop_on_err)
iput(inode);
btrfs_btree_balance_dirty(root);
return err;
}
/*
* FIBMAP and others want to pass in a fake buffer head. They need to
* use BTRFS_GET_BLOCK_NO_DIRECT to make sure we don't try to memcpy
* any packed file data into the fake bh
*/
#define BTRFS_GET_BLOCK_NO_CREATE 0
#define BTRFS_GET_BLOCK_CREATE 1
#define BTRFS_GET_BLOCK_NO_DIRECT 2
/*
* FIXME create==1 doe not work.
*/
static int btrfs_get_block_lock(struct inode *inode, sector_t iblock,
struct buffer_head *result, int create)
{
int ret;
int err = 0;
u64 blocknr;
u64 extent_start = 0;
u64 extent_end = 0;
u64 objectid = inode->i_ino;
u32 found_type;
u64 alloc_hint = 0;
struct btrfs_path *path;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_file_extent_item *item;
struct btrfs_leaf *leaf;
struct btrfs_disk_key *found_key;
struct btrfs_trans_handle *trans = NULL;
path = btrfs_alloc_path();
BUG_ON(!path);
if (create & BTRFS_GET_BLOCK_CREATE) {
/*
* danger!, this only works if the page is properly up
* to date somehow
*/
trans = btrfs_start_transaction(root, 1);
if (!trans) {
err = -ENOMEM;
goto out;
}
ret = btrfs_drop_extents(trans, root, inode,
iblock << inode->i_blkbits,
(iblock + 1) << inode->i_blkbits,
&alloc_hint);
BUG_ON(ret);
}
ret = btrfs_lookup_file_extent(NULL, root, path,
objectid,
iblock << inode->i_blkbits, 0);
if (ret < 0) {
err = ret;
goto out;
}
if (ret != 0) {
if (path->slots[0] == 0) {
btrfs_release_path(root, path);
goto not_found;
}
path->slots[0]--;
}
item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
struct btrfs_file_extent_item);
leaf = btrfs_buffer_leaf(path->nodes[0]);
blocknr = btrfs_file_extent_disk_blocknr(item);
blocknr += btrfs_file_extent_offset(item);
/* are we inside the extent that was found? */
found_key = &leaf->items[path->slots[0]].key;
found_type = btrfs_disk_key_type(found_key);
if (btrfs_disk_key_objectid(found_key) != objectid ||
found_type != BTRFS_EXTENT_DATA_KEY) {
extent_end = 0;
extent_start = 0;
goto not_found;
}
found_type = btrfs_file_extent_type(item);
extent_start = btrfs_disk_key_offset(&leaf->items[path->slots[0]].key);
if (found_type == BTRFS_FILE_EXTENT_REG) {
extent_start = extent_start >> inode->i_blkbits;
extent_end = extent_start + btrfs_file_extent_num_blocks(item);
err = 0;
if (btrfs_file_extent_disk_blocknr(item) == 0)
goto out;
if (iblock >= extent_start && iblock < extent_end) {
btrfs_map_bh_to_logical(root, result, blocknr +
iblock - extent_start);
goto out;
}
} else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
char *ptr;
char *map;
u32 size;
if (create & BTRFS_GET_BLOCK_NO_DIRECT) {
err = -EINVAL;
goto out;
}
size = btrfs_file_extent_inline_len(leaf->items +
path->slots[0]);
extent_end = (extent_start + size) >> inode->i_blkbits;
extent_start >>= inode->i_blkbits;
if (iblock < extent_start || iblock > extent_end) {
goto not_found;
}
ptr = btrfs_file_extent_inline_start(item);
map = kmap(result->b_page);
memcpy(map, ptr, size);
memset(map + size, 0, PAGE_CACHE_SIZE - size);
flush_dcache_page(result->b_page);
kunmap(result->b_page);
set_buffer_uptodate(result);
SetPageChecked(result->b_page);
btrfs_map_bh_to_logical(root, result, 0);
}
not_found:
if (create & BTRFS_GET_BLOCK_CREATE) {
struct btrfs_key ins;
ret = btrfs_alloc_extent(trans, root, inode->i_ino,
1, alloc_hint, (u64)-1,
&ins, 1);
if (ret) {
err = ret;
goto out;
}
ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
iblock << inode->i_blkbits,
ins.objectid, ins.offset,
ins.offset);
if (ret) {
err = ret;
goto out;
}
btrfs_map_bh_to_logical(root, result, ins.objectid);
}
out:
if (trans) {
ret = btrfs_end_transaction(trans, root);
if (!err)
err = ret;
}
btrfs_free_path(path);
return err;
}
int btrfs_get_block(struct inode *inode, sector_t iblock,
struct buffer_head *result, int create)
{
int err;
struct btrfs_root *root = BTRFS_I(inode)->root;
mutex_lock(&root->fs_info->fs_mutex);
err = btrfs_get_block_lock(inode, iblock, result, create);
mutex_unlock(&root->fs_info->fs_mutex);
return err;
}
static int btrfs_get_block_csum(struct inode *inode, sector_t iblock,
struct buffer_head *result, int create)
{
int ret;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct page *page = result->b_page;
u64 offset = (page->index << PAGE_CACHE_SHIFT) + bh_offset(result);
struct btrfs_csum_item *item;
struct btrfs_path *path = NULL;
mutex_lock(&root->fs_info->fs_mutex);
ret = btrfs_get_block_lock(inode, iblock, result, create);
if (ret)
goto out;
path = btrfs_alloc_path();
item = btrfs_lookup_csum(NULL, root, path, inode->i_ino, offset, 0);
if (IS_ERR(item)) {
ret = PTR_ERR(item);
/* a csum that isn't present is a preallocated region. */
if (ret == -ENOENT || ret == -EFBIG)
ret = 0;
result->b_private = NULL;
goto out;
}
memcpy((char *)&result->b_private, &item->csum, BTRFS_CRC32_SIZE);
out:
if (path)
btrfs_free_path(path);
mutex_unlock(&root->fs_info->fs_mutex);
return ret;
}
static int btrfs_get_block_bmap(struct inode *inode, sector_t iblock,
struct buffer_head *result, int create)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
mutex_lock(&root->fs_info->fs_mutex);
btrfs_get_block_lock(inode, iblock, result, BTRFS_GET_BLOCK_NO_DIRECT);
mutex_unlock(&root->fs_info->fs_mutex);
return 0;
}
static sector_t btrfs_bmap(struct address_space *as, sector_t block)
{
return generic_block_bmap(as, block, btrfs_get_block_bmap);
}
static int btrfs_prepare_write(struct file *file, struct page *page,
unsigned from, unsigned to)
{
return block_prepare_write(page, from, to, btrfs_get_block);
}
static void buffer_io_error(struct buffer_head *bh)
{
char b[BDEVNAME_SIZE];
printk(KERN_ERR "Buffer I/O error on device %s, logical block %Lu\n",
bdevname(bh->b_bdev, b),
(unsigned long long)bh->b_blocknr);
}
/*
* I/O completion handler for block_read_full_page() - pages
* which come unlocked at the end of I/O.
*/
static void btrfs_end_buffer_async_read(struct buffer_head *bh, int uptodate)
{
unsigned long flags;
struct buffer_head *first;
struct buffer_head *tmp;
struct page *page;
int page_uptodate = 1;
struct inode *inode;
int ret;
BUG_ON(!buffer_async_read(bh));
page = bh->b_page;
inode = page->mapping->host;
if (uptodate) {
void *kaddr;
struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
if (bh->b_private) {
char csum[BTRFS_CRC32_SIZE];
kaddr = kmap_atomic(page, KM_IRQ0);
ret = btrfs_csum_data(root, kaddr + bh_offset(bh),
bh->b_size, csum);
BUG_ON(ret);
if (memcmp(csum, &bh->b_private, BTRFS_CRC32_SIZE)) {
u64 offset;
offset = (page->index << PAGE_CACHE_SHIFT) +
bh_offset(bh);
printk("btrfs csum failed ino %lu off %llu\n",
page->mapping->host->i_ino,
(unsigned long long)offset);
memset(kaddr + bh_offset(bh), 1, bh->b_size);
flush_dcache_page(page);
}
kunmap_atomic(kaddr, KM_IRQ0);
}
set_buffer_uptodate(bh);
} else {
clear_buffer_uptodate(bh);
if (printk_ratelimit())
buffer_io_error(bh);
SetPageError(page);
}
/*
* Be _very_ careful from here on. Bad things can happen if
* two buffer heads end IO at almost the same time and both
* decide that the page is now completely done.
*/
first = page_buffers(page);
local_irq_save(flags);
bit_spin_lock(BH_Uptodate_Lock, &first->b_state);
clear_buffer_async_read(bh);
unlock_buffer(bh);
tmp = bh;
do {
if (!buffer_uptodate(tmp))
page_uptodate = 0;
if (buffer_async_read(tmp)) {
BUG_ON(!buffer_locked(tmp));
goto still_busy;
}
tmp = tmp->b_this_page;
} while (tmp != bh);
bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
local_irq_restore(flags);
/*
* If none of the buffers had errors and they are all
* uptodate then we can set the page uptodate.
*/
if (page_uptodate && !PageError(page))
SetPageUptodate(page);
unlock_page(page);
return;
still_busy:
bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
local_irq_restore(flags);
return;
}
/*
* Generic "read page" function for block devices that have the normal
* get_block functionality. This is most of the block device filesystems.
* Reads the page asynchronously --- the unlock_buffer() and
* set/clear_buffer_uptodate() functions propagate buffer state into the
* page struct once IO has completed.
*/
int btrfs_readpage(struct file *file, struct page *page)
{
struct inode *inode = page->mapping->host;
sector_t iblock, lblock;
struct buffer_head *bh, *head, *arr[MAX_BUF_PER_PAGE];
unsigned int blocksize;
int nr, i;
int fully_mapped = 1;
BUG_ON(!PageLocked(page));
blocksize = 1 << inode->i_blkbits;
if (!page_has_buffers(page))
create_empty_buffers(page, blocksize, 0);
head = page_buffers(page);
iblock = (sector_t)page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
lblock = (i_size_read(inode)+blocksize-1) >> inode->i_blkbits;
bh = head;
nr = 0;
i = 0;
do {
if (buffer_uptodate(bh))
continue;
if (!buffer_mapped(bh)) {
int err = 0;
fully_mapped = 0;
if (iblock < lblock) {
WARN_ON(bh->b_size != blocksize);
err = btrfs_get_block_csum(inode, iblock,
bh, 0);
if (err)
SetPageError(page);
}
if (!buffer_mapped(bh)) {
void *kaddr = kmap_atomic(page, KM_USER0);
memset(kaddr + i * blocksize, 0, blocksize);
flush_dcache_page(page);
kunmap_atomic(kaddr, KM_USER0);
if (!err)
set_buffer_uptodate(bh);
continue;
}
/*
* get_block() might have updated the buffer
* synchronously
*/
if (buffer_uptodate(bh))
continue;
}
arr[nr++] = bh;
} while (i++, iblock++, (bh = bh->b_this_page) != head);
if (fully_mapped)
SetPageMappedToDisk(page);
if (!nr) {
/*
* All buffers are uptodate - we can set the page uptodate
* as well. But not if get_block() returned an error.
*/
if (!PageError(page))
SetPageUptodate(page);
unlock_page(page);
return 0;
}
/* Stage two: lock the buffers */
for (i = 0; i < nr; i++) {
bh = arr[i];
lock_buffer(bh);
bh->b_end_io = btrfs_end_buffer_async_read;
set_buffer_async_read(bh);
}
/*
* Stage 3: start the IO. Check for uptodateness
* inside the buffer lock in case another process reading
* the underlying blockdev brought it uptodate (the sct fix).
*/
for (i = 0; i < nr; i++) {
bh = arr[i];
if (buffer_uptodate(bh))
btrfs_end_buffer_async_read(bh, 1);
else
submit_bh(READ, bh);
}
return 0;
}
/*
* Aside from a tiny bit of packed file data handling, this is the
* same as the generic code.
*
* While block_write_full_page is writing back the dirty buffers under
* the page lock, whoever dirtied the buffers may decide to clean them
* again at any time. We handle that by only looking at the buffer
* state inside lock_buffer().
*
* If block_write_full_page() is called for regular writeback
* (wbc->sync_mode == WB_SYNC_NONE) then it will redirty a page which has a
* locked buffer. This only can happen if someone has written the buffer
* directly, with submit_bh(). At the address_space level PageWriteback
* prevents this contention from occurring.
*/
static int __btrfs_write_full_page(struct inode *inode, struct page *page,
struct writeback_control *wbc)
{
int err;
sector_t block;
sector_t last_block;
struct buffer_head *bh, *head;
const unsigned blocksize = 1 << inode->i_blkbits;
int nr_underway = 0;
struct btrfs_root *root = BTRFS_I(inode)->root;
BUG_ON(!PageLocked(page));
last_block = (i_size_read(inode) - 1) >> inode->i_blkbits;
/* no csumming allowed when from PF_MEMALLOC */
if (current->flags & PF_MEMALLOC) {
redirty_page_for_writepage(wbc, page);
unlock_page(page);
return 0;
}
if (!page_has_buffers(page)) {
create_empty_buffers(page, blocksize,
(1 << BH_Dirty)|(1 << BH_Uptodate));
}
/*
* Be very careful. We have no exclusion from __set_page_dirty_buffers
* here, and the (potentially unmapped) buffers may become dirty at
* any time. If a buffer becomes dirty here after we've inspected it
* then we just miss that fact, and the page stays dirty.
*
* Buffers outside i_size may be dirtied by __set_page_dirty_buffers;
* handle that here by just cleaning them.
*/
block = (sector_t)page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
head = page_buffers(page);
bh = head;
/*
* Get all the dirty buffers mapped to disk addresses and
* handle any aliases from the underlying blockdev's mapping.
*/
do {
if (block > last_block) {
/*
* mapped buffers outside i_size will occur, because
* this page can be outside i_size when there is a
* truncate in progress.
*/
/*
* The buffer was zeroed by block_write_full_page()
*/
clear_buffer_dirty(bh);
set_buffer_uptodate(bh);
} else if (!buffer_mapped(bh) && buffer_dirty(bh)) {
WARN_ON(bh->b_size != blocksize);
err = btrfs_get_block(inode, block, bh, 0);
if (err) {
goto recover;
}
if (buffer_new(bh)) {
/* blockdev mappings never come here */
clear_buffer_new(bh);
}
}
bh = bh->b_this_page;
block++;
} while (bh != head);
do {
if (!buffer_mapped(bh))
continue;
/*
* If it's a fully non-blocking write attempt and we cannot
* lock the buffer then redirty the page. Note that this can
* potentially cause a busy-wait loop from pdflush and kswapd
* activity, but those code paths have their own higher-level
* throttling.
*/
if (wbc->sync_mode != WB_SYNC_NONE || !wbc->nonblocking) {
lock_buffer(bh);
} else if (test_set_buffer_locked(bh)) {
redirty_page_for_writepage(wbc, page);
continue;
}
if (test_clear_buffer_dirty(bh) && bh->b_blocknr != 0) {
struct btrfs_trans_handle *trans;
int ret;
u64 off = page->index << PAGE_CACHE_SHIFT;
char *kaddr;
off += bh_offset(bh);
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, inode);
kaddr = kmap(page);
btrfs_csum_file_block(trans, root, inode->i_ino,
off, kaddr + bh_offset(bh),
bh->b_size);
kunmap(page);
ret = btrfs_end_transaction(trans, root);
BUG_ON(ret);
mutex_unlock(&root->fs_info->fs_mutex);
mark_buffer_async_write(bh);
} else {
unlock_buffer(bh);
}
} while ((bh = bh->b_this_page) != head);
/*
* The page and its buffers are protected by PageWriteback(), so we can
* drop the bh refcounts early.
*/
BUG_ON(PageWriteback(page));
set_page_writeback(page);
do {
struct buffer_head *next = bh->b_this_page;
if (buffer_async_write(bh)) {
submit_bh(WRITE, bh);
nr_underway++;
}
bh = next;
} while (bh != head);
unlock_page(page);
err = 0;
done:
if (nr_underway == 0) {
/*
* The page was marked dirty, but the buffers were
* clean. Someone wrote them back by hand with
* ll_rw_block/submit_bh. A rare case.
*/
int uptodate = 1;
do {
if (!buffer_uptodate(bh)) {
uptodate = 0;
break;
}
bh = bh->b_this_page;
} while (bh != head);
if (uptodate)
SetPageUptodate(page);
end_page_writeback(page);
}
return err;
recover:
/*
* ENOSPC, or some other error. We may already have added some
* blocks to the file, so we need to write these out to avoid
* exposing stale data.
* The page is currently locked and not marked for writeback
*/
bh = head;
/* Recovery: lock and submit the mapped buffers */
do {
if (buffer_mapped(bh) && buffer_dirty(bh)) {
lock_buffer(bh);
mark_buffer_async_write(bh);
} else {
/*
* The buffer may have been set dirty during
* attachment to a dirty page.
*/
clear_buffer_dirty(bh);
}
} while ((bh = bh->b_this_page) != head);
SetPageError(page);
BUG_ON(PageWriteback(page));
set_page_writeback(page);
do {
struct buffer_head *next = bh->b_this_page;
if (buffer_async_write(bh)) {
clear_buffer_dirty(bh);
submit_bh(WRITE, bh);
nr_underway++;
}
bh = next;
} while (bh != head);
unlock_page(page);
goto done;
}
static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
{
struct inode * const inode = page->mapping->host;
loff_t i_size = i_size_read(inode);
const pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
unsigned offset;
void *kaddr;
/* Is the page fully inside i_size? */
if (page->index < end_index)
return __btrfs_write_full_page(inode, page, wbc);
/* Is the page fully outside i_size? (truncate in progress) */
offset = i_size & (PAGE_CACHE_SIZE-1);
if (page->index >= end_index+1 || !offset) {
/*
* The page may have dirty, unmapped buffers. For example,
* they may have been added in ext3_writepage(). Make them
* freeable here, so the page does not leak.
*/
block_invalidatepage(page, 0);
unlock_page(page);
return 0; /* don't care */
}
/*
* The page straddles i_size. It must be zeroed out on each and every
* writepage invokation because it may be mmapped. "A file is mapped
* in multiples of the page size. For a file that is not a multiple of
* the page size, the remaining memory is zeroed when mapped, and
* writes to that region are not written out to the file."
*/
kaddr = kmap_atomic(page, KM_USER0);
memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset);
flush_dcache_page(page);
kunmap_atomic(kaddr, KM_USER0);
return __btrfs_write_full_page(inode, page, wbc);
}
/*
* btrfs_page_mkwrite() is not allowed to change the file size as it gets
* called from a page fault handler when a page is first dirtied. Hence we must
* be careful to check for EOF conditions here. We set the page up correctly
* for a written page which means we get ENOSPC checking when writing into
* holes and correct delalloc and unwritten extent mapping on filesystems that
* support these features.
*
* We are not allowed to take the i_mutex here so we have to play games to
* protect against truncate races as the page could now be beyond EOF. Because
* vmtruncate() writes the inode size before removing pages, once we have the
* page lock we can determine safely if the page is beyond EOF. If it is not
* beyond EOF, then the page is guaranteed safe against truncation until we
* unlock the page.
*/
int btrfs_page_mkwrite(struct vm_area_struct *vma, struct page *page)
{
struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
unsigned long end;
loff_t size;
int ret = -EINVAL;
lock_page(page);
wait_on_page_writeback(page);
size = i_size_read(inode);
if ((page->mapping != inode->i_mapping) ||
((page->index << PAGE_CACHE_SHIFT) > size)) {
/* page got truncated out from underneath us */
goto out_unlock;
}
/* page is wholly or partially inside EOF */
if (((page->index + 1) << PAGE_CACHE_SHIFT) > size)
end = size & ~PAGE_CACHE_MASK;
else
end = PAGE_CACHE_SIZE;
ret = btrfs_prepare_write(NULL, page, 0, end);
if (!ret)
ret = btrfs_commit_write(NULL, page, 0, end);
out_unlock:
unlock_page(page);
return ret;
}
static void btrfs_truncate(struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
int ret;
struct btrfs_trans_handle *trans;
if (!S_ISREG(inode->i_mode))
return;
if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
return;
btrfs_truncate_page(inode->i_mapping, inode->i_size);
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, inode);
/* FIXME, add redo link to tree so we don't leak on crash */
ret = btrfs_truncate_in_trans(trans, root, inode);
btrfs_update_inode(trans, root, inode);
ret = btrfs_end_transaction(trans, root);
BUG_ON(ret);
mutex_unlock(&root->fs_info->fs_mutex);
btrfs_btree_balance_dirty(root);
}
int btrfs_commit_write(struct file *file, struct page *page,
unsigned from, unsigned to)
{
struct inode *inode = page->mapping->host;
struct buffer_head *bh;
loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
SetPageUptodate(page);
bh = page_buffers(page);
set_buffer_uptodate(bh);
if (buffer_mapped(bh) && bh->b_blocknr != 0) {
set_page_dirty(page);
}
if (pos > inode->i_size) {
i_size_write(inode, pos);
mark_inode_dirty(inode);
}
return 0;
}
static int create_subvol(struct btrfs_root *root, 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 buffer_head *subvol;
struct btrfs_leaf *leaf;
struct btrfs_root *new_root;
struct inode *inode;
struct inode *dir;
int ret;
int err;
u64 objectid;
u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
BUG_ON(!trans);
subvol = btrfs_alloc_free_block(trans, root, 0);
if (IS_ERR(subvol))
return PTR_ERR(subvol);
leaf = btrfs_buffer_leaf(subvol);
btrfs_set_header_nritems(&leaf->header, 0);
btrfs_set_header_level(&leaf->header, 0);
btrfs_set_header_blocknr(&leaf->header, bh_blocknr(subvol));
btrfs_set_header_generation(&leaf->header, trans->transid);
btrfs_set_header_owner(&leaf->header, root->root_key.objectid);
memcpy(leaf->header.fsid, root->fs_info->disk_super->fsid,
sizeof(leaf->header.fsid));
mark_buffer_dirty(subvol);
inode_item = &root_item.inode;
memset(inode_item, 0, sizeof(*inode_item));
btrfs_set_inode_generation(inode_item, 1);
btrfs_set_inode_size(inode_item, 3);
btrfs_set_inode_nlink(inode_item, 1);
btrfs_set_inode_nblocks(inode_item, 1);
btrfs_set_inode_mode(inode_item, S_IFDIR | 0755);
btrfs_set_root_blocknr(&root_item, bh_blocknr(subvol));
btrfs_set_root_refs(&root_item, 1);
memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
root_item.drop_level = 0;
brelse(subvol);
subvol = NULL;
ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
0, &objectid);
if (ret)
goto fail;
btrfs_set_root_dirid(&root_item, new_dirid);
key.objectid = objectid;
key.offset = 1;
key.flags = 0;
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 = root->fs_info->sb->s_root->d_inode;
ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
name, namelen, dir->i_ino, &key,
BTRFS_FT_DIR);
if (ret)
goto fail;
ret = btrfs_commit_transaction(trans, root);
if (ret)
goto fail_commit;
new_root = btrfs_read_fs_root(root->fs_info, &key);
BUG_ON(!new_root);
trans = btrfs_start_transaction(new_root, 1);
BUG_ON(!trans);
inode = btrfs_new_inode(trans, new_root, new_dirid,
BTRFS_I(dir)->block_group, S_IFDIR | 0700);
if (IS_ERR(inode))
goto fail;
inode->i_op = &btrfs_dir_inode_operations;
inode->i_fop = &btrfs_dir_file_operations;
new_root->inode = inode;
ret = btrfs_make_empty_dir(trans, new_root, new_dirid, new_dirid);
if (ret)
goto fail;
inode->i_nlink = 1;
inode->i_size = 6;
ret = btrfs_update_inode(trans, new_root, inode);
if (ret)
goto fail;
fail:
err = btrfs_commit_transaction(trans, root);
if (err && !ret)
ret = err;
fail_commit:
mutex_unlock(&root->fs_info->fs_mutex);
btrfs_btree_balance_dirty(root);
return ret;
}
static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
{
struct btrfs_trans_handle *trans;
struct btrfs_key key;
struct btrfs_root_item new_root_item;
int ret;
int err;
u64 objectid;
if (!root->ref_cows)
return -EINVAL;
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
BUG_ON(!trans);
ret = btrfs_update_inode(trans, root, root->inode);
if (ret)
goto fail;
ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
0, &objectid);
if (ret)
goto fail;
memcpy(&new_root_item, &root->root_item,
sizeof(new_root_item));
key.objectid = objectid;
key.offset = 1;
key.flags = 0;
btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
btrfs_set_root_blocknr(&new_root_item, bh_blocknr(root->node));
ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
&new_root_item);
if (ret)
goto fail;
/*
* insert the directory item
*/
key.offset = (u64)-1;
ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
name, namelen,
root->fs_info->sb->s_root->d_inode->i_ino,
&key, BTRFS_FT_DIR);
if (ret)
goto fail;
ret = btrfs_inc_root_ref(trans, root);
if (ret)
goto fail;
fail:
err = btrfs_commit_transaction(trans, root);
if (err && !ret)
ret = err;
mutex_unlock(&root->fs_info->fs_mutex);
btrfs_btree_balance_dirty(root);
return ret;
}
int btrfs_ioctl(struct inode *inode, struct file *filp, unsigned int
cmd, unsigned long arg)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_ioctl_vol_args vol_args;
int ret = 0;
struct btrfs_dir_item *di;
int namelen;
struct btrfs_path *path;
u64 root_dirid;
switch (cmd) {
case BTRFS_IOC_SNAP_CREATE:
if (copy_from_user(&vol_args,
(struct btrfs_ioctl_vol_args __user *)arg,
sizeof(vol_args)))
return -EFAULT;
namelen = strlen(vol_args.name);
if (namelen > BTRFS_VOL_NAME_MAX)
return -EINVAL;
if (strchr(vol_args.name, '/'))
return -EINVAL;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
root_dirid = root->fs_info->sb->s_root->d_inode->i_ino,
mutex_lock(&root->fs_info->fs_mutex);
di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root,
path, root_dirid,
vol_args.name, namelen, 0);
mutex_unlock(&root->fs_info->fs_mutex);
btrfs_free_path(path);
if (di && !IS_ERR(di))
return -EEXIST;
if (IS_ERR(di))
return PTR_ERR(di);
if (root == root->fs_info->tree_root)
ret = create_subvol(root, vol_args.name, namelen);
else
ret = create_snapshot(root, vol_args.name, namelen);
break;
default:
return -ENOTTY;
}
return ret;
}
#ifdef CONFIG_COMPAT
long btrfs_compat_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
struct inode *inode = file->f_path.dentry->d_inode;
int ret;
lock_kernel();
ret = btrfs_ioctl(inode, file, cmd, (unsigned long) compat_ptr(arg));
unlock_kernel();
return ret;
}
#endif
/*
* Called inside transaction, so use GFP_NOFS
*/
struct inode *btrfs_alloc_inode(struct super_block *sb)
{
struct btrfs_inode *ei;
ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
if (!ei)
return NULL;
return &ei->vfs_inode;
}
void btrfs_destroy_inode(struct inode *inode)
{
WARN_ON(!list_empty(&inode->i_dentry));
WARN_ON(inode->i_data.nrpages);
kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
}
static void init_once(void * foo, struct kmem_cache * cachep,
unsigned long flags)
{
struct btrfs_inode *ei = (struct btrfs_inode *) foo;
inode_init_once(&ei->vfs_inode);
}
void btrfs_destroy_cachep(void)
{
if (btrfs_inode_cachep)
kmem_cache_destroy(btrfs_inode_cachep);
if (btrfs_trans_handle_cachep)
kmem_cache_destroy(btrfs_trans_handle_cachep);
if (btrfs_transaction_cachep)
kmem_cache_destroy(btrfs_transaction_cachep);
if (btrfs_bit_radix_cachep)
kmem_cache_destroy(btrfs_bit_radix_cachep);
if (btrfs_path_cachep)
kmem_cache_destroy(btrfs_path_cachep);
}
int btrfs_init_cachep(void)
{
btrfs_inode_cachep = kmem_cache_create("btrfs_inode_cache",
sizeof(struct btrfs_inode),
0, (SLAB_RECLAIM_ACCOUNT|
SLAB_MEM_SPREAD),
init_once, NULL);
if (!btrfs_inode_cachep)
goto fail;
btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle_cache",
sizeof(struct btrfs_trans_handle),
0, (SLAB_RECLAIM_ACCOUNT|
SLAB_MEM_SPREAD),
NULL, NULL);
if (!btrfs_trans_handle_cachep)
goto fail;
btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction_cache",
sizeof(struct btrfs_transaction),
0, (SLAB_RECLAIM_ACCOUNT|
SLAB_MEM_SPREAD),
NULL, NULL);
if (!btrfs_transaction_cachep)
goto fail;
btrfs_path_cachep = kmem_cache_create("btrfs_path_cache",
sizeof(struct btrfs_transaction),
0, (SLAB_RECLAIM_ACCOUNT|
SLAB_MEM_SPREAD),
NULL, NULL);
if (!btrfs_path_cachep)
goto fail;
btrfs_bit_radix_cachep = kmem_cache_create("btrfs_radix",
256,
0, (SLAB_RECLAIM_ACCOUNT|
SLAB_MEM_SPREAD |
SLAB_DESTROY_BY_RCU),
NULL, NULL);
if (!btrfs_bit_radix_cachep)
goto fail;
return 0;
fail:
btrfs_destroy_cachep();
return -ENOMEM;
}
static int btrfs_getattr(struct vfsmount *mnt,
struct dentry *dentry, struct kstat *stat)
{
struct inode *inode = dentry->d_inode;
generic_fillattr(inode, stat);
stat->blksize = 256 * 1024;
return 0;
}
static int btrfs_rename(struct inode * old_dir, struct dentry *old_dentry,
struct inode * new_dir,struct dentry *new_dentry)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(old_dir)->root;
struct inode *new_inode = new_dentry->d_inode;
struct inode *old_inode = old_dentry->d_inode;
struct timespec ctime = CURRENT_TIME;
struct btrfs_path *path;
struct btrfs_dir_item *di;
int ret;
if (S_ISDIR(old_inode->i_mode) && new_inode &&
new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) {
return -ENOTEMPTY;
}
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, new_dir);
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto out_fail;
}
old_dentry->d_inode->i_nlink++;
old_dir->i_ctime = old_dir->i_mtime = ctime;
new_dir->i_ctime = new_dir->i_mtime = ctime;
old_inode->i_ctime = ctime;
if (S_ISDIR(old_inode->i_mode) && old_dir != new_dir) {
struct btrfs_key *location = &BTRFS_I(new_dir)->location;
u64 old_parent_oid;
di = btrfs_lookup_dir_item(trans, root, path, old_inode->i_ino,
"..", 2, -1);
if (IS_ERR(di)) {
ret = PTR_ERR(di);
goto out_fail;
}
if (!di) {
ret = -ENOENT;
goto out_fail;
}
old_parent_oid = btrfs_disk_key_objectid(&di->location);
ret = btrfs_del_item(trans, root, path);
if (ret) {
goto out_fail;
}
btrfs_release_path(root, path);
di = btrfs_lookup_dir_index_item(trans, root, path,
old_inode->i_ino,
old_parent_oid,
"..", 2, -1);
if (IS_ERR(di)) {
ret = PTR_ERR(di);
goto out_fail;
}
if (!di) {
ret = -ENOENT;
goto out_fail;
}
ret = btrfs_del_item(trans, root, path);
if (ret) {
goto out_fail;
}
btrfs_release_path(root, path);
ret = btrfs_insert_dir_item(trans, root, "..", 2,
old_inode->i_ino, location,
BTRFS_FT_DIR);
if (ret)
goto out_fail;
}
ret = btrfs_unlink_trans(trans, root, old_dir, old_dentry);
if (ret)
goto out_fail;
if (new_inode) {
new_inode->i_ctime = CURRENT_TIME;
ret = btrfs_unlink_trans(trans, root, new_dir, new_dentry);
if (ret)
goto out_fail;
if (S_ISDIR(new_inode->i_mode))
clear_nlink(new_inode);
else
drop_nlink(new_inode);
ret = btrfs_update_inode(trans, root, new_inode);
if (ret)
goto out_fail;
}
ret = btrfs_add_link(trans, new_dentry, old_inode);
if (ret)
goto out_fail;
out_fail:
btrfs_free_path(path);
btrfs_end_transaction(trans, root);
mutex_unlock(&root->fs_info->fs_mutex);
return ret;
}
static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
const char *symname)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_path *path;
struct btrfs_key key;
struct inode *inode;
int err;
int drop_inode = 0;
u64 objectid;
int name_len;
int datasize;
char *ptr;
struct btrfs_file_extent_item *ei;
name_len = strlen(symname) + 1;
if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
return -ENAMETOOLONG;
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, dir);
err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
if (err) {
err = -ENOSPC;
goto out_unlock;
}
inode = btrfs_new_inode(trans, root, objectid,
BTRFS_I(dir)->block_group, S_IFLNK|S_IRWXUGO);
err = PTR_ERR(inode);
if (IS_ERR(inode))
goto out_unlock;
btrfs_set_trans_block_group(trans, inode);
err = btrfs_add_nondir(trans, dentry, inode);
if (err)
drop_inode = 1;
else {
inode->i_mapping->a_ops = &btrfs_aops;
inode->i_fop = &btrfs_file_operations;
inode->i_op = &btrfs_file_inode_operations;
}
dir->i_sb->s_dirt = 1;
btrfs_update_inode_block_group(trans, inode);
btrfs_update_inode_block_group(trans, dir);
if (drop_inode)
goto out_unlock;
path = btrfs_alloc_path();
BUG_ON(!path);
key.objectid = inode->i_ino;
key.offset = 0;
key.flags = 0;
btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
datasize = btrfs_file_extent_calc_inline_size(name_len);
err = btrfs_insert_empty_item(trans, root, path, &key,
datasize);
if (err) {
drop_inode = 1;
goto out_unlock;
}
ei = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
path->slots[0], struct btrfs_file_extent_item);
btrfs_set_file_extent_generation(ei, trans->transid);
btrfs_set_file_extent_type(ei,
BTRFS_FILE_EXTENT_INLINE);
ptr = btrfs_file_extent_inline_start(ei);
btrfs_memcpy(root, path->nodes[0]->b_data,
ptr, symname, name_len);
mark_buffer_dirty(path->nodes[0]);
btrfs_free_path(path);
inode->i_op = &btrfs_symlink_inode_operations;
inode->i_mapping->a_ops = &btrfs_symlink_aops;
inode->i_size = name_len - 1;
err = btrfs_update_inode(trans, root, inode);
if (err)
drop_inode = 1;
out_unlock:
btrfs_end_transaction(trans, root);
mutex_unlock(&root->fs_info->fs_mutex);
if (drop_inode) {
inode_dec_link_count(inode);
iput(inode);
}
btrfs_btree_balance_dirty(root);
return err;
}
static struct inode_operations btrfs_dir_inode_operations = {
.lookup = btrfs_lookup,
.create = btrfs_create,
.unlink = btrfs_unlink,
.link = btrfs_link,
.mkdir = btrfs_mkdir,
.rmdir = btrfs_rmdir,
.rename = btrfs_rename,
.symlink = btrfs_symlink,
.setattr = btrfs_setattr,
};
static struct inode_operations btrfs_dir_ro_inode_operations = {
.lookup = btrfs_lookup,
};
static struct file_operations btrfs_dir_file_operations = {
.llseek = generic_file_llseek,
.read = generic_read_dir,
.readdir = btrfs_readdir,
.ioctl = btrfs_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = btrfs_compat_ioctl,
#endif
};
static struct address_space_operations btrfs_aops = {
.readpage = btrfs_readpage,
.writepage = btrfs_writepage,
.sync_page = block_sync_page,
.prepare_write = btrfs_prepare_write,
.commit_write = btrfs_commit_write,
.bmap = btrfs_bmap,
};
static struct address_space_operations btrfs_symlink_aops = {
.readpage = btrfs_readpage,
.writepage = btrfs_writepage,
};
static struct inode_operations btrfs_file_inode_operations = {
.truncate = btrfs_truncate,
.getattr = btrfs_getattr,
.setattr = btrfs_setattr,
};
static struct inode_operations btrfs_symlink_inode_operations = {
.readlink = generic_readlink,
.follow_link = page_follow_link_light,
.put_link = page_put_link,
};
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