linux/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/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 <linux/version.h>
#include <linux/xattr.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_special_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 extent_map_ops btrfs_extent_map_ops;
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,
};
static int run_delalloc_range(struct inode *inode, u64 start, u64 end)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans;
struct btrfs_key ins;
u64 alloc_hint = 0;
u64 num_bytes;
int ret;
u64 blocksize = root->sectorsize;
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, inode);
BUG_ON(!trans);
num_bytes = (end - start + blocksize) & ~(blocksize - 1);
ret = btrfs_drop_extents(trans, root, inode,
start, start + num_bytes, start, &alloc_hint);
if (alloc_hint == EXTENT_MAP_INLINE)
goto out;
ret = btrfs_alloc_extent(trans, root, inode->i_ino, num_bytes, 0,
alloc_hint, (u64)-1, &ins, 1);
if (ret) {
WARN_ON(1);
goto out;
}
ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
start, ins.objectid, ins.offset,
ins.offset);
out:
btrfs_end_transaction(trans, root);
mutex_unlock(&root->fs_info->fs_mutex);
return ret;
}
int btrfs_writepage_io_hook(struct page *page, u64 start, u64 end)
{
struct inode *inode = page->mapping->host;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans;
char *kaddr;
int ret;
u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
size_t offset = start - page_start;
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, inode->i_ino,
start, kaddr + offset, end - start + 1);
kunmap(page);
ret = btrfs_end_transaction(trans, root);
BUG_ON(ret);
mutex_unlock(&root->fs_info->fs_mutex);
return ret;
}
int btrfs_readpage_io_hook(struct page *page, u64 start, u64 end)
{
int ret = 0;
struct inode *inode = page->mapping->host;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
struct btrfs_csum_item *item;
struct btrfs_path *path = NULL;
u32 csum;
mutex_lock(&root->fs_info->fs_mutex);
path = btrfs_alloc_path();
item = btrfs_lookup_csum(NULL, root, path, inode->i_ino, start, 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;
csum = 0;
goto out;
}
read_extent_buffer(path->nodes[0], &csum, (unsigned long)item,
BTRFS_CRC32_SIZE);
set_state_private(em_tree, start, csum);
out:
if (path)
btrfs_free_path(path);
mutex_unlock(&root->fs_info->fs_mutex);
return ret;
}
int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end)
{
size_t offset = start - ((u64)page->index << PAGE_CACHE_SHIFT);
struct inode *inode = page->mapping->host;
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
char *kaddr;
u64 private;
int ret;
struct btrfs_root *root = BTRFS_I(inode)->root;
u32 csum = ~(u32)0;
unsigned long flags;
ret = get_state_private(em_tree, start, &private);
local_irq_save(flags);
kaddr = kmap_atomic(page, KM_IRQ0);
if (ret) {
goto zeroit;
}
csum = btrfs_csum_data(root, kaddr + offset, csum, end - start + 1);
btrfs_csum_final(csum, (char *)&csum);
if (csum != private) {
goto zeroit;
}
kunmap_atomic(kaddr, KM_IRQ0);
local_irq_restore(flags);
return 0;
zeroit:
printk("btrfs csum failed ino %lu off %llu\n",
page->mapping->host->i_ino, (unsigned long long)start);
memset(kaddr + offset, 1, end - start + 1);
flush_dcache_page(page);
kunmap_atomic(kaddr, KM_IRQ0);
local_irq_restore(flags);
return 0;
}
void btrfs_read_locked_inode(struct inode *inode)
{
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_inode_item *inode_item;
struct btrfs_inode_timespec *tspec;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_key location;
u64 alloc_group_block;
u32 rdev;
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)
goto make_bad;
leaf = path->nodes[0];
inode_item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_inode_item);
inode->i_mode = btrfs_inode_mode(leaf, inode_item);
inode->i_nlink = btrfs_inode_nlink(leaf, inode_item);
inode->i_uid = btrfs_inode_uid(leaf, inode_item);
inode->i_gid = btrfs_inode_gid(leaf, inode_item);
inode->i_size = btrfs_inode_size(leaf, inode_item);
tspec = btrfs_inode_atime(inode_item);
inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
tspec = btrfs_inode_mtime(inode_item);
inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
tspec = btrfs_inode_ctime(inode_item);
inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
inode->i_blocks = btrfs_inode_nblocks(leaf, inode_item);
inode->i_generation = btrfs_inode_generation(leaf, inode_item);
inode->i_rdev = 0;
rdev = btrfs_inode_rdev(leaf, inode_item);
alloc_group_block = btrfs_inode_block_group(leaf, 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) {
case S_IFREG:
inode->i_mapping->a_ops = &btrfs_aops;
BTRFS_I(inode)->extent_tree.ops = &btrfs_extent_map_ops;
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;
default:
init_special_inode(inode, inode->i_mode, rdev);
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 extent_buffer *leaf,
struct btrfs_inode_item *item,
struct inode *inode)
{
btrfs_set_inode_uid(leaf, item, inode->i_uid);
btrfs_set_inode_gid(leaf, item, inode->i_gid);
btrfs_set_inode_size(leaf, item, inode->i_size);
btrfs_set_inode_mode(leaf, item, inode->i_mode);
btrfs_set_inode_nlink(leaf, item, inode->i_nlink);
btrfs_set_timespec_sec(leaf, btrfs_inode_atime(item),
inode->i_atime.tv_sec);
btrfs_set_timespec_nsec(leaf, btrfs_inode_atime(item),
inode->i_atime.tv_nsec);
btrfs_set_timespec_sec(leaf, btrfs_inode_mtime(item),
inode->i_mtime.tv_sec);
btrfs_set_timespec_nsec(leaf, btrfs_inode_mtime(item),
inode->i_mtime.tv_nsec);
btrfs_set_timespec_sec(leaf, btrfs_inode_ctime(item),
inode->i_ctime.tv_sec);
btrfs_set_timespec_nsec(leaf, btrfs_inode_ctime(item),
inode->i_ctime.tv_nsec);
btrfs_set_inode_nblocks(leaf, item, inode->i_blocks);
btrfs_set_inode_generation(leaf, item, inode->i_generation);
btrfs_set_inode_rdev(leaf, item, inode->i_rdev);
btrfs_set_inode_block_group(leaf, item,
BTRFS_I(inode)->block_group->key.objectid);
}
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;
struct extent_buffer *leaf;
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;
}
leaf = path->nodes[0];
inode_item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_inode_item);
fill_inode_item(leaf, inode_item, inode);
btrfs_mark_buffer_dirty(leaf);
btrfs_set_inode_last_trans(trans, inode);
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;
struct extent_buffer *leaf;
struct btrfs_dir_item *di;
struct btrfs_key key;
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;
}
leaf = path->nodes[0];
btrfs_dir_item_key_to_cpu(leaf, di, &key);
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,
key.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;
unsigned long nr;
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);
nr = trans->blocks_used;
btrfs_end_transaction(trans, root);
mutex_unlock(&root->fs_info->fs_mutex);
btrfs_btree_balance_dirty(root, nr);
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 extent_buffer *leaf;
char *goodnames = "..";
unsigned long nr;
if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
return -ENOTEMPTY;
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.type = (u8)-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 = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
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);
nr = trans->blocks_used;
ret = btrfs_end_transaction(trans, root);
mutex_unlock(&root->fs_info->fs_mutex);
btrfs_btree_balance_dirty(root, nr);
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;
}
/*
* 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_key found_key;
u32 found_type;
struct extent_buffer *leaf;
struct btrfs_file_extent_item *fi;
u64 extent_start = 0;
u64 extent_num_bytes = 0;
u64 item_end = 0;
int found_extent;
int del_item;
int extent_type = -1;
btrfs_drop_extent_cache(inode, inode->i_size, (u64)-1);
path = btrfs_alloc_path();
path->reada = -1;
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.type = (u8)-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]--;
}
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
found_type = btrfs_key_type(&found_key);
if (found_key.objectid != 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 = found_key.offset;
if (found_type == BTRFS_EXTENT_DATA_KEY) {
fi = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
extent_type = btrfs_file_extent_type(leaf, fi);
if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
item_end +=
btrfs_file_extent_num_bytes(leaf, fi);
} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
struct btrfs_item *item = btrfs_item_nr(leaf,
path->slots[0]);
item_end += btrfs_file_extent_inline_len(leaf,
item);
}
item_end--;
}
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_DIR_ITEM_KEY) {
found_type = BTRFS_INODE_ITEM_KEY;
} else if (found_type == BTRFS_EXTENT_ITEM_KEY) {
found_type = BTRFS_CSUM_ITEM_KEY;
} else if (found_type) {
found_type--;
} else {
break;
}
btrfs_set_key_type(&key, found_type);
btrfs_release_path(root, path);
continue;
}
if (found_key.offset >= 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)
goto delete;
if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
u64 num_dec;
extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
if (!del_item) {
u64 orig_num_bytes =
btrfs_file_extent_num_bytes(leaf, fi);
extent_num_bytes = inode->i_size -
found_key.offset + root->sectorsize - 1;
btrfs_set_file_extent_num_bytes(leaf, fi,
extent_num_bytes);
num_dec = (orig_num_bytes -
extent_num_bytes) >> 9;
if (extent_start != 0) {
inode->i_blocks -= num_dec;
}
btrfs_mark_buffer_dirty(leaf);
} else {
extent_num_bytes =
btrfs_file_extent_disk_num_bytes(leaf,
fi);
/* FIXME blocksize != 4096 */
num_dec = btrfs_file_extent_num_bytes(leaf,
fi) >> 9;
if (extent_start != 0) {
found_extent = 1;
inode->i_blocks -= num_dec;
}
}
} else if (extent_type == BTRFS_FILE_EXTENT_INLINE &&
!del_item) {
u32 newsize = inode->i_size - found_key.offset;
newsize = btrfs_file_extent_calc_inline_size(newsize);
ret = btrfs_truncate_item(trans, root, path,
newsize, 1);
BUG_ON(ret);
}
delete:
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_bytes, 0);
BUG_ON(ret);
}
}
ret = 0;
error:
btrfs_release_path(root, path);
btrfs_free_path(path);
inode->i_sb->s_dirt = 1;
return ret;
}
static int btrfs_cow_one_page(struct inode *inode, struct page *page,
size_t zero_start)
{
char *kaddr;
int ret = 0;
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
u64 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
set_page_extent_mapped(page);
lock_extent(em_tree, page_start, page_end, GFP_NOFS);
set_extent_delalloc(&BTRFS_I(inode)->extent_tree, page_start,
page_end, GFP_NOFS);
if (zero_start != PAGE_CACHE_SIZE) {
kaddr = kmap(page);
memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
flush_dcache_page(page);
kunmap(page);
}
set_page_dirty(page);
unlock_extent(em_tree, page_start, page_end, GFP_NOFS);
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;
struct btrfs_root *root = BTRFS_I(inode)->root;
u32 blocksize = root->sectorsize;
pgoff_t index = from >> PAGE_CACHE_SHIFT;
unsigned offset = from & (PAGE_CACHE_SIZE-1);
struct page *page;
int ret = 0;
u64 page_start;
if ((offset & (blocksize - 1)) == 0)
goto out;
down_read(&root->snap_sem);
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;
}
}
page_start = (u64)page->index << PAGE_CACHE_SHIFT;
ret = btrfs_cow_one_page(inode, page, offset);
unlock_page(page);
page_cache_release(page);
up_read(&BTRFS_I(inode)->root->snap_sem);
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;
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
u64 mask = root->sectorsize - 1;
u64 pos = (inode->i_size + mask) & ~mask;
u64 block_end = attr->ia_size | mask;
u64 hole_size;
u64 alloc_hint = 0;
if (attr->ia_size <= pos)
goto out;
btrfs_truncate_page(inode->i_mapping, inode->i_size);
lock_extent(em_tree, pos, block_end, GFP_NOFS);
hole_size = (attr->ia_size - pos + mask) & ~mask;
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, inode);
err = btrfs_drop_extents(trans, root, inode,
pos, pos + hole_size, pos,
&alloc_hint);
if (alloc_hint != EXTENT_MAP_INLINE) {
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);
unlock_extent(em_tree, pos, block_end, GFP_NOFS);
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;
unsigned long nr;
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_delete_xattrs(trans, root, inode);
if (ret)
goto no_delete_lock;
ret = btrfs_free_inode(trans, root, inode);
if (ret)
goto no_delete_lock;
nr = trans->blocks_used;
btrfs_end_transaction(trans, root);
mutex_unlock(&root->fs_info->fs_mutex);
btrfs_btree_balance_dirty(root, nr);
return;
no_delete_lock:
nr = trans->blocks_used;
btrfs_end_transaction(trans, root);
mutex_unlock(&root->fs_info->fs_mutex);
btrfs_btree_balance_dirty(root, nr);
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 = 0;
path = btrfs_alloc_path();
BUG_ON(!path);
di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
namelen, 0);
if (IS_ERR(di))
ret = PTR_ERR(di);
if (!di || IS_ERR(di)) {
location->objectid = 0;
goto out;
}
btrfs_dir_item_key_to_cpu(path->nodes[0], 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 dentry *dentry)
{
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,
dentry->d_name.name,
dentry->d_name.len);
if (IS_ERR(*sub_root))
return PTR_ERR(*sub_root);
ri = &(*sub_root)->root_item;
location->objectid = btrfs_root_dirid(ri);
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;
extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
inode->i_mapping, GFP_NOFS);
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,
dentry);
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);
}
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_key found_key;
struct btrfs_path *path;
int ret;
u32 nritems;
struct extent_buffer *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;
char tmp_name[32];
char *name_ptr;
int name_len;
/* 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;
btrfs_set_key_type(&key, key_type);
key.offset = filp->f_pos;
path = btrfs_alloc_path();
path->reada = 2;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto err;
advance = 0;
while(1) {
leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
slot = path->slots[0];
if (advance || slot >= nritems) {
if (slot >= nritems -1) {
ret = btrfs_next_leaf(root, path);
if (ret)
break;
leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
slot = path->slots[0];
} else {
slot++;
path->slots[0]++;
}
}
advance = 1;
item = btrfs_item_nr(leaf, slot);
btrfs_item_key_to_cpu(leaf, &found_key, slot);
if (found_key.objectid != key.objectid)
break;
if (btrfs_key_type(&found_key) != key_type)
break;
if (found_key.offset < filp->f_pos)
continue;
filp->f_pos = found_key.offset;
advance = 1;
di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
di_cur = 0;
di_total = btrfs_item_size(leaf, item);
while(di_cur < di_total) {
struct btrfs_key location;
name_len = btrfs_dir_name_len(leaf, di);
if (name_len < 32) {
name_ptr = tmp_name;
} else {
name_ptr = kmalloc(name_len, GFP_NOFS);
BUG_ON(!name_ptr);
}
read_extent_buffer(leaf, name_ptr,
(unsigned long)(di + 1), name_len);
d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
btrfs_dir_item_key_to_cpu(leaf, di, &location);
over = filldir(dirent, name_ptr, name_len,
found_key.offset,
location.objectid,
d_type);
if (name_ptr != tmp_name)
kfree(name_ptr);
if (over)
goto nopos;
di_len = btrfs_dir_name_len(leaf, di) +
btrfs_dir_data_len(leaf, 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;
struct btrfs_path *path;
int ret;
int owner;
path = btrfs_alloc_path();
BUG_ON(!path);
inode = new_inode(root->fs_info->sb);
if (!inode)
return ERR_PTR(-ENOMEM);
extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
inode->i_mapping, GFP_NOFS);
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;
ret = btrfs_insert_empty_inode(trans, root, path, objectid);
if (ret)
goto fail;
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;
inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_inode_item);
fill_inode_item(path->nodes[0], inode_item, inode);
btrfs_mark_buffer_dirty(path->nodes[0]);
btrfs_free_path(path);
location = &BTRFS_I(inode)->location;
location->objectid = objectid;
location->offset = 0;
btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
insert_inode_hash(inode);
return inode;
fail:
btrfs_free_path(path);
return ERR_PTR(ret);
}
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;
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_mknod(struct inode *dir, struct dentry *dentry,
int mode, dev_t rdev)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct inode *inode;
int err;
int drop_inode = 0;
u64 objectid;
unsigned long nr;
if (!new_valid_dev(rdev))
return -EINVAL;
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_op = &btrfs_special_inode_operations;
init_special_inode(inode, inode->i_mode, rdev);
btrfs_update_inode(trans, root, inode);
}
dir->i_sb->s_dirt = 1;
btrfs_update_inode_block_group(trans, inode);
btrfs_update_inode_block_group(trans, dir);
out_unlock:
nr = trans->blocks_used;
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, nr);
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;
unsigned long nr;
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;
extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
inode->i_mapping, GFP_NOFS);
BTRFS_I(inode)->extent_tree.ops = &btrfs_extent_map_ops;
}
dir->i_sb->s_dirt = 1;
btrfs_update_inode_block_group(trans, inode);
btrfs_update_inode_block_group(trans, dir);
out_unlock:
nr = trans->blocks_used;
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, nr);
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;
unsigned long nr;
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;
nr = trans->blocks_used;
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, nr);
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;
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;
unsigned long nr = 1;
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:
nr = trans->blocks_used;
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, nr);
return err;
}
struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
size_t page_offset, u64 start, u64 end,
int create)
{
int ret;
int err = 0;
u64 bytenr;
u64 extent_start = 0;
u64 extent_end = 0;
u64 objectid = inode->i_ino;
u32 found_type;
int failed_insert = 0;
struct btrfs_path *path;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_file_extent_item *item;
struct extent_buffer *leaf;
struct btrfs_key found_key;
struct extent_map *em = NULL;
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
struct btrfs_trans_handle *trans = NULL;
path = btrfs_alloc_path();
BUG_ON(!path);
mutex_lock(&root->fs_info->fs_mutex);
again:
em = lookup_extent_mapping(em_tree, start, end);
if (em) {
goto out;
}
if (!em) {
em = alloc_extent_map(GFP_NOFS);
if (!em) {
err = -ENOMEM;
goto out;
}
em->start = EXTENT_MAP_HOLE;
em->end = EXTENT_MAP_HOLE;
}
em->bdev = inode->i_sb->s_bdev;
ret = btrfs_lookup_file_extent(trans, root, path,
objectid, start, trans != NULL);
if (ret < 0) {
err = ret;
goto out;
}
if (ret != 0) {
if (path->slots[0] == 0)
goto not_found;
path->slots[0]--;
}
leaf = path->nodes[0];
item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
/* are we inside the extent that was found? */
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
found_type = btrfs_key_type(&found_key);
if (found_key.objectid != objectid ||
found_type != BTRFS_EXTENT_DATA_KEY) {
goto not_found;
}
found_type = btrfs_file_extent_type(leaf, item);
extent_start = found_key.offset;
if (found_type == BTRFS_FILE_EXTENT_REG) {
extent_end = extent_start +
btrfs_file_extent_num_bytes(leaf, item);
err = 0;
if (start < extent_start || start >= extent_end) {
em->start = start;
if (start < extent_start) {
if (end < extent_start)
goto not_found;
em->end = extent_end - 1;
} else {
em->end = end;
}
goto not_found_em;
}
bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
if (bytenr == 0) {
em->start = extent_start;
em->end = extent_end - 1;
em->block_start = EXTENT_MAP_HOLE;
em->block_end = EXTENT_MAP_HOLE;
goto insert;
}
bytenr += btrfs_file_extent_offset(leaf, item);
em->block_start = bytenr;
em->block_end = em->block_start +
btrfs_file_extent_num_bytes(leaf, item) - 1;
em->start = extent_start;
em->end = extent_end - 1;
goto insert;
} else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
unsigned long ptr;
char *map;
size_t size;
size_t extent_offset;
size_t copy_size;
size = btrfs_file_extent_inline_len(leaf, btrfs_item_nr(leaf,
path->slots[0]));
extent_end = (extent_start + size - 1) |
((u64)root->sectorsize - 1);
if (start < extent_start || start >= extent_end) {
em->start = start;
if (start < extent_start) {
if (end < extent_start)
goto not_found;
em->end = extent_end;
} else {
em->end = end;
}
goto not_found_em;
}
em->block_start = EXTENT_MAP_INLINE;
em->block_end = EXTENT_MAP_INLINE;
if (!page) {
em->start = extent_start;
em->end = extent_start + size - 1;
goto out;
}
extent_offset = ((u64)page->index << PAGE_CACHE_SHIFT) -
extent_start + page_offset;
copy_size = min_t(u64, PAGE_CACHE_SIZE - page_offset,
size - extent_offset);
em->start = extent_start + extent_offset;
em->end = (em->start + copy_size -1) |
((u64)root->sectorsize -1);
map = kmap(page);
ptr = btrfs_file_extent_inline_start(item) + extent_offset;
if (create == 0 && !PageUptodate(page)) {
read_extent_buffer(leaf, map + page_offset, ptr,
copy_size);
flush_dcache_page(page);
} else if (create && PageUptodate(page)) {
if (!trans) {
kunmap(page);
free_extent_map(em);
em = NULL;
btrfs_release_path(root, path);
trans = btrfs_start_transaction(root, 1);
goto again;
}
write_extent_buffer(leaf, map + page_offset, ptr,
copy_size);
btrfs_mark_buffer_dirty(leaf);
}
kunmap(page);
set_extent_uptodate(em_tree, em->start, em->end, GFP_NOFS);
goto insert;
} else {
printk("unkknown found_type %d\n", found_type);
WARN_ON(1);
}
not_found:
em->start = start;
em->end = end;
not_found_em:
em->block_start = EXTENT_MAP_HOLE;
em->block_end = EXTENT_MAP_HOLE;
insert:
btrfs_release_path(root, path);
if (em->start > start || em->end < start) {
printk("bad extent! em: [%Lu %Lu] passed [%Lu %Lu]\n", em->start, em->end, start, end);
err = -EIO;
goto out;
}
ret = add_extent_mapping(em_tree, em);
if (ret == -EEXIST) {
free_extent_map(em);
em = NULL;
failed_insert++;
if (failed_insert > 5) {
printk("failing to insert %Lu %Lu\n", start, end);
err = -EIO;
goto out;
}
goto again;
}
err = 0;
out:
btrfs_free_path(path);
if (trans) {
ret = btrfs_end_transaction(trans, root);
if (!err)
err = ret;
}
mutex_unlock(&root->fs_info->fs_mutex);
if (err) {
free_extent_map(em);
WARN_ON(1);
return ERR_PTR(err);
}
return em;
}
static sector_t btrfs_bmap(struct address_space *mapping, sector_t iblock)
{
return extent_bmap(mapping, iblock, btrfs_get_extent);
}
static int btrfs_prepare_write(struct file *file, struct page *page,
unsigned from, unsigned to)
{
return extent_prepare_write(&BTRFS_I(page->mapping->host)->extent_tree,
page->mapping->host, page, from, to,
btrfs_get_extent);
}
int btrfs_readpage(struct file *file, struct page *page)
{
struct extent_map_tree *tree;
tree = &BTRFS_I(page->mapping->host)->extent_tree;
return extent_read_full_page(tree, page, btrfs_get_extent);
}
static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
{
struct extent_map_tree *tree;
if (current->flags & PF_MEMALLOC) {
redirty_page_for_writepage(wbc, page);
unlock_page(page);
return 0;
}
tree = &BTRFS_I(page->mapping->host)->extent_tree;
return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
}
static int btrfs_writepages(struct address_space *mapping,
struct writeback_control *wbc)
{
struct extent_map_tree *tree;
tree = &BTRFS_I(mapping->host)->extent_tree;
return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
}
static int
btrfs_readpages(struct file *file, struct address_space *mapping,
struct list_head *pages, unsigned nr_pages)
{
struct extent_map_tree *tree;
tree = &BTRFS_I(mapping->host)->extent_tree;
return extent_readpages(tree, mapping, pages, nr_pages,
btrfs_get_extent);
}
static int btrfs_releasepage(struct page *page, gfp_t unused_gfp_flags)
{
struct extent_map_tree *tree;
int ret;
tree = &BTRFS_I(page->mapping->host)->extent_tree;
ret = try_release_extent_mapping(tree, page);
if (ret == 1) {
ClearPagePrivate(page);
set_page_private(page, 0);
page_cache_release(page);
}
return ret;
}
static void btrfs_invalidatepage(struct page *page, unsigned long offset)
{
struct extent_map_tree *tree;
tree = &BTRFS_I(page->mapping->host)->extent_tree;
extent_invalidatepage(tree, page, offset);
btrfs_releasepage(page, GFP_NOFS);
}
/*
* 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;
u64 page_start;
down_read(&BTRFS_I(inode)->root->snap_sem);
lock_page(page);
wait_on_page_writeback(page);
size = i_size_read(inode);
page_start = (u64)page->index << PAGE_CACHE_SHIFT;
if ((page->mapping != inode->i_mapping) ||
(page_start > size)) {
/* page got truncated out from underneath us */
goto out_unlock;
}
/* page is wholly or partially inside EOF */
if (page_start + PAGE_CACHE_SIZE > size)
end = size & ~PAGE_CACHE_MASK;
else
end = PAGE_CACHE_SIZE;
ret = btrfs_cow_one_page(inode, page, end);
out_unlock:
up_read(&BTRFS_I(inode)->root->snap_sem);
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;
unsigned long nr;
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);
nr = trans->blocks_used;
ret = btrfs_end_transaction(trans, root);
BUG_ON(ret);
mutex_unlock(&root->fs_info->fs_mutex);
btrfs_btree_balance_dirty(root, nr);
}
int btrfs_commit_write(struct file *file, struct page *page,
unsigned from, unsigned to)
{
return extent_commit_write(&BTRFS_I(page->mapping->host)->extent_tree,
page->mapping->host, page, from, to);
}
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 extent_buffer *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;
unsigned long nr = 1;
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
BUG_ON(!trans);
leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0, 0);
if (IS_ERR(leaf))
return PTR_ERR(leaf);
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, root->root_key.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->nblocks = cpu_to_le64(1);
inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
btrfs_set_root_bytenr(&root_item, leaf->start);
btrfs_set_root_level(&root_item, 0);
btrfs_set_root_refs(&root_item, 1);
btrfs_set_root_used(&root_item, 0);
memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
root_item.drop_level = 0;
free_extent_buffer(leaf);
leaf = 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;
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, name, namelen);
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:
nr = trans->blocks_used;
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, nr);
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;
struct extent_buffer *tmp;
int ret;
int err;
u64 objectid;
unsigned long nr;
if (!root->ref_cows)
return -EINVAL;
down_write(&root->snap_sem);
freeze_bdev(root->fs_info->sb->s_bdev);
thaw_bdev(root->fs_info->sb->s_bdev, root->fs_info->sb);
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;
btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
btrfs_cow_block(trans, root, root->node, NULL, 0, &tmp);
btrfs_set_root_bytenr(&new_root_item, root->node->start);
btrfs_set_root_level(&new_root_item, btrfs_header_level(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:
nr = trans->blocks_used;
err = btrfs_commit_transaction(trans, root);
if (err && !ret)
ret = err;
mutex_unlock(&root->fs_info->fs_mutex);
up_write(&root->snap_sem);
btrfs_btree_balance_dirty(root, nr);
return ret;
}
static unsigned long force_ra(struct address_space *mapping,
struct file_ra_state *ra, struct file *file,
pgoff_t offset, pgoff_t last_index)
{
pgoff_t req_size;
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
req_size = last_index - offset + 1;
offset = page_cache_readahead(mapping, ra, file, offset, req_size);
return offset;
#else
req_size = min(last_index - offset + 1, (pgoff_t)128);
page_cache_sync_readahead(mapping, ra, file, offset, req_size);
return offset + req_size;
#endif
}
int btrfs_defrag_file(struct file *file) {
struct inode *inode = file->f_path.dentry->d_inode;
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
struct page *page;
unsigned long last_index;
unsigned long ra_index = 0;
u64 page_start;
u64 page_end;
unsigned long i;
mutex_lock(&inode->i_mutex);
last_index = inode->i_size >> PAGE_CACHE_SHIFT;
for (i = 0; i <= last_index; i++) {
if (i == ra_index) {
ra_index = force_ra(inode->i_mapping, &file->f_ra,
file, ra_index, last_index);
}
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;
}
}
page_start = (u64)page->index << PAGE_CACHE_SHIFT;
page_end = page_start + PAGE_CACHE_SIZE - 1;
lock_extent(em_tree, page_start, page_end, GFP_NOFS);
set_extent_delalloc(em_tree, page_start,
page_end, GFP_NOFS);
unlock_extent(em_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;
}
static int btrfs_ioctl_snap_create(struct btrfs_root *root, void __user *arg)
{
struct btrfs_ioctl_vol_args vol_args;
struct btrfs_dir_item *di;
struct btrfs_path *path;
int namelen;
u64 root_dirid;
if (copy_from_user(&vol_args, 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)
return create_subvol(root, vol_args.name, namelen);
return create_snapshot(root, vol_args.name, namelen);
}
static int btrfs_ioctl_defrag(struct file *file)
{
struct inode *inode = file->f_path.dentry->d_inode;
struct btrfs_root *root = BTRFS_I(inode)->root;
switch (inode->i_mode & S_IFMT) {
case S_IFDIR:
mutex_lock(&root->fs_info->fs_mutex);
btrfs_defrag_root(root, 0);
btrfs_defrag_root(root->fs_info->extent_root, 0);
mutex_unlock(&root->fs_info->fs_mutex);
break;
case S_IFREG:
btrfs_defrag_file(file);
break;
}
return 0;
}
long btrfs_ioctl(struct file *file, unsigned int
cmd, unsigned long arg)
{
struct btrfs_root *root = BTRFS_I(file->f_path.dentry->d_inode)->root;
switch (cmd) {
case BTRFS_IOC_SNAP_CREATE:
return btrfs_ioctl_snap_create(root, (void __user *)arg);
case BTRFS_IOC_DEFRAG:
return btrfs_ioctl_defrag(file);
}
return -ENOTTY;
}
/*
* 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;
ei->last_trans = 0;
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));
}
#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
static void init_once(struct kmem_cache * cachep, void *foo)
#else
static void init_once(void * foo, struct kmem_cache * cachep,
unsigned long flags)
#endif
{
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);
}
struct kmem_cache *btrfs_cache_create(const char *name, size_t size,
unsigned long extra_flags,
#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
void (*ctor)(struct kmem_cache *, void *)
#else
void (*ctor)(void *, struct kmem_cache *,
unsigned long)
#endif
)
{
return kmem_cache_create(name, size, 0, (SLAB_RECLAIM_ACCOUNT |
SLAB_MEM_SPREAD | extra_flags), ctor
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
,NULL
#endif
);
}
int btrfs_init_cachep(void)
{
btrfs_inode_cachep = btrfs_cache_create("btrfs_inode_cache",
sizeof(struct btrfs_inode),
0, init_once);
if (!btrfs_inode_cachep)
goto fail;
btrfs_trans_handle_cachep =
btrfs_cache_create("btrfs_trans_handle_cache",
sizeof(struct btrfs_trans_handle),
0, NULL);
if (!btrfs_trans_handle_cachep)
goto fail;
btrfs_transaction_cachep = btrfs_cache_create("btrfs_transaction_cache",
sizeof(struct btrfs_transaction),
0, NULL);
if (!btrfs_transaction_cachep)
goto fail;
btrfs_path_cachep = btrfs_cache_create("btrfs_path_cache",
sizeof(struct btrfs_path),
0, NULL);
if (!btrfs_path_cachep)
goto fail;
btrfs_bit_radix_cachep = btrfs_cache_create("btrfs_radix", 256,
SLAB_DESTROY_BY_RCU, 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;
struct btrfs_key old_parent_key;
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;
}
btrfs_dir_item_key_to_cpu(path->nodes[0], di, &old_parent_key);
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_key.objectid,
"..", 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;
}
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;
unsigned long ptr;
struct btrfs_file_extent_item *ei;
struct extent_buffer *leaf;
unsigned long nr;
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;
extent_map_tree_init(&BTRFS_I(inode)->extent_tree,
inode->i_mapping, GFP_NOFS);
BTRFS_I(inode)->extent_tree.ops = &btrfs_extent_map_ops;
}
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;
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;
}
leaf = path->nodes[0];
ei = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
btrfs_set_file_extent_generation(leaf, ei, trans->transid);
btrfs_set_file_extent_type(leaf, ei,
BTRFS_FILE_EXTENT_INLINE);
ptr = btrfs_file_extent_inline_start(ei);
write_extent_buffer(leaf, symname, ptr, name_len);
btrfs_mark_buffer_dirty(leaf);
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:
nr = trans->blocks_used;
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, nr);
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,
.mknod = btrfs_mknod,
.setxattr = generic_setxattr,
.getxattr = generic_getxattr,
.listxattr = btrfs_listxattr,
.removexattr = generic_removexattr,
};
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,
.unlocked_ioctl = btrfs_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = btrfs_ioctl,
#endif
};
static struct extent_map_ops btrfs_extent_map_ops = {
.fill_delalloc = run_delalloc_range,
.writepage_io_hook = btrfs_writepage_io_hook,
.readpage_io_hook = btrfs_readpage_io_hook,
.readpage_end_io_hook = btrfs_readpage_end_io_hook,
};
static struct address_space_operations btrfs_aops = {
.readpage = btrfs_readpage,
.writepage = btrfs_writepage,
.writepages = btrfs_writepages,
.readpages = btrfs_readpages,
.sync_page = block_sync_page,
.prepare_write = btrfs_prepare_write,
.commit_write = btrfs_commit_write,
.bmap = btrfs_bmap,
.invalidatepage = btrfs_invalidatepage,
.releasepage = btrfs_releasepage,
.set_page_dirty = __set_page_dirty_nobuffers,
};
static struct address_space_operations btrfs_symlink_aops = {
.readpage = btrfs_readpage,
.writepage = btrfs_writepage,
.invalidatepage = btrfs_invalidatepage,
.releasepage = btrfs_releasepage,
};
static struct inode_operations btrfs_file_inode_operations = {
.truncate = btrfs_truncate,
.getattr = btrfs_getattr,
.setattr = btrfs_setattr,
.setxattr = generic_setxattr,
.getxattr = generic_getxattr,
.listxattr = btrfs_listxattr,
.removexattr = generic_removexattr,
};
static struct inode_operations btrfs_special_inode_operations = {
.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,
};