linux/fs/btrfs/super.c

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#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 "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "btrfs_inode.h"
#define BTRFS_SUPER_MAGIC 0x9123682E
static struct inode_operations btrfs_dir_inode_operations;
static struct super_operations btrfs_super_ops;
static struct file_operations btrfs_dir_file_operations;
static struct inode_operations btrfs_file_inode_operations;
static struct address_space_operations btrfs_aops;
static struct file_operations btrfs_file_operations;
static int check_inode(struct inode *inode)
{
struct btrfs_inode *ei = BTRFS_I(inode);
WARN_ON(ei->magic != 0xDEADBEEF);
WARN_ON(ei->magic2 != 0xDEADBEAF);
return 0;
}
static void btrfs_read_locked_inode(struct inode *inode)
{
struct btrfs_path *path;
struct btrfs_inode_item *inode_item;
struct btrfs_root *root = btrfs_sb(inode->i_sb);
int ret;
path = btrfs_alloc_path();
BUG_ON(!path);
btrfs_init_path(path);
mutex_lock(&root->fs_info->fs_mutex);
check_inode(inode);
ret = btrfs_lookup_inode(NULL, root, path, inode->i_ino, 0);
if (ret) {
btrfs_release_path(root, path);
btrfs_free_path(path);
mutex_unlock(&root->fs_info->fs_mutex);
make_bad_inode(inode);
return;
}
check_inode(inode);
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);
btrfs_release_path(root, path);
btrfs_free_path(path);
inode_item = NULL;
mutex_unlock(&root->fs_info->fs_mutex);
check_inode(inode);
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_op = &btrfs_dir_inode_operations;
inode->i_fop = &btrfs_dir_file_operations;
break;
case S_IFLNK:
// inode->i_op = &page_symlink_inode_operations;
break;
}
check_inode(inode);
return;
}
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;
u64 objectid;
struct btrfs_dir_item *di;
path = btrfs_alloc_path();
BUG_ON(!path);
btrfs_init_path(path);
ret = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
name, name_len, -1);
if (ret < 0)
goto err;
if (ret > 0) {
ret = -ENOENT;
goto err;
}
di = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
struct btrfs_dir_item);
objectid = btrfs_dir_objectid(di);
ret = btrfs_del_item(trans, root, path);
BUG_ON(ret);
dentry->d_inode->i_ctime = dir->i_ctime;
err:
btrfs_release_path(root, path);
btrfs_free_path(path);
if (ret == 0)
inode_dec_link_count(dentry->d_inode);
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_sb(dir->i_sb);
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
ret = btrfs_unlink_trans(trans, root, dir, dentry);
btrfs_end_transaction(trans, root);
mutex_unlock(&root->fs_info->fs_mutex);
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_sb(dir->i_sb);
struct btrfs_path *path;
struct btrfs_key key;
struct btrfs_trans_handle *trans;
struct btrfs_disk_key *found_key;
struct btrfs_leaf *leaf;
path = btrfs_alloc_path();
BUG_ON(!path);
btrfs_init_path(path);
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
key.objectid = inode->i_ino;
key.offset = (u64)-1;
key.flags = 0;
btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret < 0) {
err = ret;
goto out;
}
BUG_ON(ret == 0);
BUG_ON(path->slots[0] == 0);
path->slots[0]--;
leaf = btrfs_buffer_leaf(path->nodes[0]);
found_key = &leaf->items[path->slots[0]].key;
if (btrfs_disk_key_objectid(found_key) != inode->i_ino) {
err = -ENOENT;
goto out;
}
if (btrfs_disk_key_type(found_key) != BTRFS_DIR_ITEM_KEY ||
btrfs_disk_key_offset(found_key) != 2) {
err = -ENOTEMPTY;
goto out;
}
ret = btrfs_del_item(trans, root, path);
BUG_ON(ret);
btrfs_release_path(root, path);
key.offset = 1;
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret < 0) {
err = ret;
goto out;
}
if (ret > 0) {
err = -ENOTEMPTY;
goto out;
}
ret = btrfs_del_item(trans, root, path);
if (ret) {
err = ret;
goto out;
}
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);
if (ret && !err)
err = ret;
return err;
}
static int btrfs_free_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *inode)
{
u64 objectid = inode->i_ino;
struct btrfs_path *path;
struct btrfs_inode_map_item *map;
struct btrfs_key stat_data_key;
int ret;
clear_inode(inode);
path = btrfs_alloc_path();
BUG_ON(!path);
btrfs_init_path(path);
ret = btrfs_lookup_inode_map(trans, root, path, objectid, -1);
if (ret) {
if (ret > 0)
ret = -ENOENT;
goto error;
}
map = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
struct btrfs_inode_map_item);
btrfs_disk_key_to_cpu(&stat_data_key, &map->key);
ret = btrfs_del_item(trans, root->fs_info->inode_root, path);
BUG_ON(ret);
btrfs_release_path(root, path);
ret = btrfs_lookup_inode(trans, root, path, objectid, -1);
BUG_ON(ret);
ret = btrfs_del_item(trans, root, path);
BUG_ON(ret);
error:
btrfs_release_path(root, path);
btrfs_free_path(path);
return ret;
}
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;
struct btrfs_leaf *leaf;
struct btrfs_file_extent_item *fi = NULL;
u64 extent_start = 0;
u64 extent_num_blocks = 0;
int found_extent;
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 = 0;
btrfs_set_key_type(&key, BTRFS_CSUM_ITEM_KEY);
while(1) {
btrfs_init_path(path);
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 = btrfs_buffer_leaf(path->nodes[0]);
found_key = &leaf->items[path->slots[0]].key;
if (btrfs_disk_key_objectid(found_key) != inode->i_ino)
break;
if (btrfs_disk_key_type(found_key) != BTRFS_CSUM_ITEM_KEY &&
btrfs_disk_key_type(found_key) != BTRFS_EXTENT_DATA_KEY)
break;
if (btrfs_disk_key_offset(found_key) < inode->i_size)
break;
if (btrfs_disk_key_type(found_key) == BTRFS_EXTENT_DATA_KEY) {
fi = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
path->slots[0],
struct btrfs_file_extent_item);
extent_start = btrfs_file_extent_disk_blocknr(fi);
extent_num_blocks =
btrfs_file_extent_disk_num_blocks(fi);
inode->i_blocks -=
btrfs_file_extent_num_blocks(fi) >> 9;
found_extent = 1;
} else {
found_extent = 0;
}
ret = btrfs_del_item(trans, root, path);
BUG_ON(ret);
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);
return ret;
}
static void btrfs_delete_inode(struct inode *inode)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root = btrfs_sb(inode->i_sb);
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);
if (S_ISREG(inode->i_mode)) {
ret = btrfs_truncate_in_trans(trans, root, inode);
BUG_ON(ret);
}
btrfs_free_inode(trans, root, inode);
btrfs_end_transaction(trans, root);
mutex_unlock(&root->fs_info->fs_mutex);
return;
no_delete:
clear_inode(inode);
}
static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
ino_t *ino)
{
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_sb(dir->i_sb);
int ret;
path = btrfs_alloc_path();
BUG_ON(!path);
btrfs_init_path(path);
ret = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
namelen, 0);
if (ret || !btrfs_match_dir_item_name(root, path, name, namelen)) {
*ino = 0;
ret = 0;
goto out;
}
di = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
struct btrfs_dir_item);
*ino = btrfs_dir_objectid(di);
out:
btrfs_release_path(root, path);
btrfs_free_path(path);
check_inode(dir);
return ret;
}
static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
struct nameidata *nd)
{
struct inode * inode;
struct btrfs_root *root = btrfs_sb(dir->i_sb);
ino_t ino;
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, &ino);
mutex_unlock(&root->fs_info->fs_mutex);
if (ret < 0)
return ERR_PTR(ret);
inode = NULL;
if (ino) {
inode = iget(dir->i_sb, ino);
if (!inode)
return ERR_PTR(-EACCES);
check_inode(inode);
}
check_inode(dir);
return d_splice_alias(inode, dentry);
}
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_sb(inode->i_sb);
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 = DT_UNKNOWN;
int over = 0;
mutex_lock(&root->fs_info->fs_mutex);
key.objectid = inode->i_ino;
key.flags = 0;
btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
key.offset = filp->f_pos;
path = btrfs_alloc_path();
btrfs_init_path(path);
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0) {
goto err;
}
advance = 0;
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) {
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) != BTRFS_DIR_ITEM_KEY)
continue;
if (btrfs_disk_key_offset(&item->key) < filp->f_pos)
continue;
advance = 1;
di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
over = filldir(dirent, (const char *)(di + 1),
btrfs_dir_name_len(di),
btrfs_disk_key_offset(&item->key),
btrfs_dir_objectid(di), d_type);
if (over) {
filp->f_pos = btrfs_disk_key_offset(&item->key);
break;
}
filp->f_pos = btrfs_disk_key_offset(&item->key) + 1;
}
ret = 0;
err:
btrfs_release_path(root, path);
btrfs_free_path(path);
mutex_unlock(&root->fs_info->fs_mutex);
return ret;
}
static void btrfs_put_super (struct super_block * sb)
{
struct btrfs_root *root = btrfs_sb(sb);
int ret;
ret = close_ctree(root);
if (ret) {
printk("close ctree returns %d\n", ret);
}
sb->s_fs_info = NULL;
}
static int btrfs_fill_super(struct super_block * sb, void * data, int silent)
{
struct inode * inode;
struct dentry * root_dentry;
struct btrfs_super_block *disk_super;
struct btrfs_root *root;
sb->s_maxbytes = MAX_LFS_FILESIZE;
sb->s_magic = BTRFS_SUPER_MAGIC;
sb->s_op = &btrfs_super_ops;
sb->s_time_gran = 1;
root = open_ctree(sb);
if (!root) {
printk("btrfs: open_ctree failed\n");
return -EIO;
}
sb->s_fs_info = root;
disk_super = root->fs_info->disk_super;
printk("read in super total blocks %Lu root %Lu\n",
btrfs_super_total_blocks(disk_super),
btrfs_super_root_dir(disk_super));
inode = iget_locked(sb, btrfs_super_root_dir(disk_super));
if (!inode)
return -ENOMEM;
if (inode->i_state & I_NEW) {
btrfs_read_locked_inode(inode);
unlock_new_inode(inode);
}
root_dentry = d_alloc_root(inode);
if (!root_dentry) {
iput(inode);
return -ENOMEM;
}
sb->s_root = root_dentry;
return 0;
}
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);
check_inode(inode);
}
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);
btrfs_init_path(path);
ret = btrfs_lookup_inode(trans, root, path, inode->i_ino, 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]);
failed:
btrfs_release_path(root, path);
btrfs_free_path(path);
check_inode(inode);
return 0;
}
static int btrfs_write_inode(struct inode *inode, int wait)
{
struct btrfs_root *root = btrfs_sb(inode->i_sb);
struct btrfs_trans_handle *trans;
int ret;
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
ret = btrfs_update_inode(trans, root, inode);
if (wait)
btrfs_commit_transaction(trans, root);
else
btrfs_end_transaction(trans, root);
mutex_unlock(&root->fs_info->fs_mutex);
check_inode(inode);
return ret;
}
static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
struct inode *dir, int mode)
{
struct inode *inode;
struct btrfs_inode_item inode_item;
struct btrfs_root *root = btrfs_sb(dir->i_sb);
struct btrfs_key key;
int ret;
u64 objectid;
inode = new_inode(dir->i_sb);
if (!inode)
return ERR_PTR(-ENOMEM);
check_inode(inode);
ret = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
BUG_ON(ret);
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_SEC;
fill_inode_item(&inode_item, inode);
key.objectid = objectid;
key.flags = 0;
key.offset = 0;
btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
ret = btrfs_insert_inode_map(trans, root, objectid, &key);
BUG_ON(ret);
ret = btrfs_insert_inode(trans, root, objectid, &inode_item);
BUG_ON(ret);
insert_inode_hash(inode);
check_inode(inode);
check_inode(dir);
return inode;
}
static int btrfs_add_link(struct btrfs_trans_handle *trans,
struct dentry *dentry, struct inode *inode)
{
int ret;
ret = btrfs_insert_dir_item(trans, btrfs_sb(inode->i_sb),
dentry->d_name.name, dentry->d_name.len,
dentry->d_parent->d_inode->i_ino,
inode->i_ino, 0);
if (ret == 0) {
dentry->d_parent->d_inode->i_size += dentry->d_name.len;
ret = btrfs_update_inode(trans, btrfs_sb(inode->i_sb),
dentry->d_parent->d_inode);
}
check_inode(inode);
check_inode(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;
check_inode(inode);
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_sb(dir->i_sb);
struct inode *inode;
int err;
int drop_inode = 0;
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
inode = btrfs_new_inode(trans, dir, mode);
err = PTR_ERR(inode);
if (IS_ERR(inode))
goto out_unlock;
// FIXME mark the inode dirty
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;
out_unlock:
btrfs_end_transaction(trans, root);
mutex_unlock(&root->fs_info->fs_mutex);
check_inode(inode);
check_inode(dir);
if (drop_inode) {
inode_dec_link_count(inode);
iput(inode);
}
return err;
}
static int btrfs_make_empty_dir(struct btrfs_trans_handle *trans,
struct inode *inode, struct inode *dir)
{
struct btrfs_root *root = btrfs_sb(inode->i_sb);
int ret;
char buf[2];
buf[0] = '.';
buf[1] = '.';
ret = btrfs_insert_dir_item(trans, root, buf, 1, inode->i_ino,
inode->i_ino, 1);
if (ret)
goto error;
ret = btrfs_insert_dir_item(trans, root, buf, 2, inode->i_ino,
dir->i_ino, 1);
if (ret)
goto error;
inode->i_size = 3;
ret = btrfs_update_inode(trans, root, inode);
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_sb(dir->i_sb);
int err = 0;
int drop_on_err = 0;
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans)) {
err = PTR_ERR(trans);
goto out_unlock;
}
inode = btrfs_new_inode(trans, dir, 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;
err = btrfs_make_empty_dir(trans, inode, dir);
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;
out_fail:
btrfs_end_transaction(trans, root);
out_unlock:
mutex_unlock(&root->fs_info->fs_mutex);
if (drop_on_err)
iput(inode);
return err;
}
static int btrfs_sync_fs(struct super_block *sb, int wait)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root;
int ret;
root = btrfs_sb(sb);
sb->s_dirt = 0;
if (!wait) {
filemap_flush(root->fs_info->btree_inode->i_mapping);
return 0;
}
filemap_write_and_wait(root->fs_info->btree_inode->i_mapping);
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
ret = btrfs_commit_transaction(trans, root);
sb->s_dirt = 0;
BUG_ON(ret);
printk("btrfs sync_fs\n");
mutex_unlock(&root->fs_info->fs_mutex);
return 0;
}
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;
struct btrfs_path *path;
struct btrfs_root *root = btrfs_sb(inode->i_sb);
struct btrfs_trans_handle *trans = NULL;
struct btrfs_file_extent_item *item;
struct btrfs_leaf *leaf;
struct btrfs_disk_key *found_key;
path = btrfs_alloc_path();
BUG_ON(!path);
btrfs_init_path(path);
if (create)
trans = btrfs_start_transaction(root, 1);
ret = btrfs_lookup_file_extent(trans, root, path,
inode->i_ino,
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 allocate;
}
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);
/* exact match found, use it */
if (ret == 0) {
err = 0;
map_bh(result, inode->i_sb, blocknr);
goto out;
}
/* are we inside the extent that was found? */
found_key = &leaf->items[path->slots[0]].key;
if (btrfs_disk_key_objectid(found_key) != objectid ||
btrfs_disk_key_type(found_key) != BTRFS_EXTENT_DATA_KEY) {
extent_end = 0;
extent_start = 0;
btrfs_release_path(root, path);
goto allocate;
}
extent_start = btrfs_disk_key_offset(&leaf->items[path->slots[0]].key);
extent_start = extent_start >> inode->i_blkbits;
extent_start += btrfs_file_extent_offset(item);
extent_end = extent_start + btrfs_file_extent_num_blocks(item);
if (iblock >= extent_start && iblock < extent_end) {
err = 0;
map_bh(result, inode->i_sb, blocknr + iblock - extent_start);
goto out;
}
allocate:
/* ok, create a new extent */
if (!create) {
err = 0;
goto out;
}
ret = btrfs_alloc_file_extent(trans, root, objectid,
iblock << inode->i_blkbits,
1, extent_end, &blocknr);
if (ret) {
err = ret;
goto out;
}
inode->i_blocks += inode->i_sb->s_blocksize >> 9;
set_buffer_new(result);
map_bh(result, inode->i_sb, blocknr);
out:
btrfs_release_path(root, path);
btrfs_free_path(path);
if (trans)
btrfs_end_transaction(trans, root);
return err;
}
static int btrfs_get_block(struct inode *inode, sector_t iblock,
struct buffer_head *result, int create)
{
int err;
struct btrfs_root *root = btrfs_sb(inode->i_sb);
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_prepare_write(struct file *file, struct page *page,
unsigned from, unsigned to)
{
WARN_ON(1);
return nobh_prepare_write(page, from, to, btrfs_get_block);
}
static int btrfs_commit_write(struct file *file, struct page *page,
unsigned from, unsigned to)
{
WARN_ON(1);
return nobh_commit_write(file, page, from, to);
}
static void btrfs_write_super(struct super_block *sb)
{
btrfs_sync_fs(sb, 1);
}
static int btrfs_readpage(struct file *file, struct page *page)
{
return mpage_readpage(page, btrfs_get_block);
}
static int btrfs_readpages(struct file *file, struct address_space *mapping,
struct list_head *pages, unsigned nr_pages)
{
return mpage_readpages(mapping, pages, nr_pages, btrfs_get_block);
}
static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
{
return nobh_writepage(page, btrfs_get_block, wbc);
}
static void btrfs_truncate(struct inode *inode)
{
struct btrfs_root *root = btrfs_sb(inode->i_sb);
int ret;
struct btrfs_trans_handle *trans;
if (!S_ISREG(inode->i_mode))
return;
if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
return;
nobh_truncate_page(inode->i_mapping, inode->i_size);
/* FIXME, add redo link to tree so we don't leak on crash */
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
ret = btrfs_truncate_in_trans(trans, root, inode);
BUG_ON(ret);
ret = btrfs_end_transaction(trans, root);
BUG_ON(ret);
mutex_unlock(&root->fs_info->fs_mutex);
mark_inode_dirty(inode);
}
static int btrfs_copy_from_user(loff_t pos, int num_pages, int write_bytes,
struct page **prepared_pages,
const char __user * buf)
{
long page_fault = 0;
int i;
int offset = pos & (PAGE_CACHE_SIZE - 1);
for (i = 0; i < num_pages && write_bytes > 0; i++, offset = 0) {
size_t count = min_t(size_t,
PAGE_CACHE_SIZE - offset, write_bytes);
struct page *page = prepared_pages[i];
fault_in_pages_readable(buf, count);
/* Copy data from userspace to the current page */
kmap(page);
page_fault = __copy_from_user(page_address(page) + offset,
buf, count);
/* Flush processor's dcache for this page */
flush_dcache_page(page);
kunmap(page);
buf += count;
write_bytes -= count;
if (page_fault)
break;
}
return page_fault ? -EFAULT : 0;
}
static void btrfs_drop_pages(struct page **pages, size_t num_pages)
{
size_t i;
for (i = 0; i < num_pages; i++) {
if (!pages[i])
break;
unlock_page(pages[i]);
mark_page_accessed(pages[i]);
page_cache_release(pages[i]);
}
}
static int dirty_and_release_pages(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct file *file,
struct page **pages,
size_t num_pages,
loff_t pos,
size_t write_bytes)
{
int i;
int offset;
int err = 0;
int ret;
int this_write;
struct inode *inode = file->f_path.dentry->d_inode;
for (i = 0; i < num_pages; i++) {
offset = pos & (PAGE_CACHE_SIZE -1);
this_write = min(PAGE_CACHE_SIZE - offset, write_bytes);
/* FIXME, one block at a time */
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
btrfs_csum_file_block(trans, root, inode->i_ino,
pages[i]->index << PAGE_CACHE_SHIFT,
kmap(pages[i]), PAGE_CACHE_SIZE);
kunmap(pages[i]);
SetPageChecked(pages[i]);
ret = btrfs_end_transaction(trans, root);
BUG_ON(ret);
mutex_unlock(&root->fs_info->fs_mutex);
ret = nobh_commit_write(file, pages[i], offset,
offset + this_write);
pos += this_write;
if (ret) {
err = ret;
goto failed;
}
WARN_ON(this_write > write_bytes);
write_bytes -= this_write;
}
failed:
return err;
}
static int prepare_pages(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct file *file,
struct page **pages,
size_t num_pages,
loff_t pos,
size_t write_bytes)
{
int i;
unsigned long index = pos >> PAGE_CACHE_SHIFT;
struct inode *inode = file->f_path.dentry->d_inode;
int offset;
int err = 0;
int ret;
int this_write;
loff_t isize = i_size_read(inode);
memset(pages, 0, num_pages * sizeof(struct page *));
for (i = 0; i < num_pages; i++) {
pages[i] = grab_cache_page(inode->i_mapping, index + i);
if (!pages[i]) {
err = -ENOMEM;
goto failed_release;
}
offset = pos & (PAGE_CACHE_SIZE -1);
this_write = min(PAGE_CACHE_SIZE - offset, write_bytes);
ret = nobh_prepare_write(pages[i], offset,
offset + this_write,
btrfs_get_block);
pos += this_write;
if (ret) {
err = ret;
goto failed_truncate;
}
WARN_ON(this_write > write_bytes);
write_bytes -= this_write;
}
return 0;
failed_release:
btrfs_drop_pages(pages, num_pages);
return err;
failed_truncate:
btrfs_drop_pages(pages, num_pages);
if (pos > isize)
vmtruncate(inode, isize);
return err;
}
static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
loff_t pos;
size_t num_written = 0;
int err = 0;
int ret = 0;
struct inode *inode = file->f_path.dentry->d_inode;
struct btrfs_root *root = btrfs_sb(inode->i_sb);
struct page *pages[1];
if (file->f_flags & O_DIRECT)
return -EINVAL;
pos = *ppos;
vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
current->backing_dev_info = inode->i_mapping->backing_dev_info;
err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
if (err)
goto out;
if (count == 0)
goto out;
err = remove_suid(file->f_path.dentry);
if (err)
goto out;
file_update_time(file);
mutex_lock(&inode->i_mutex);
while(count > 0) {
size_t offset = pos & (PAGE_CACHE_SIZE - 1);
size_t write_bytes = min(count, PAGE_CACHE_SIZE - offset);
size_t num_pages = (write_bytes + PAGE_CACHE_SIZE - 1) >>
PAGE_CACHE_SHIFT;
ret = prepare_pages(NULL, root, file, pages, num_pages,
pos, write_bytes);
BUG_ON(ret);
ret = btrfs_copy_from_user(pos, num_pages,
write_bytes, pages, buf);
BUG_ON(ret);
ret = dirty_and_release_pages(NULL, root, file, pages,
num_pages, pos, write_bytes);
BUG_ON(ret);
btrfs_drop_pages(pages, num_pages);
buf += write_bytes;
count -= write_bytes;
pos += write_bytes;
num_written += write_bytes;
balance_dirty_pages_ratelimited(inode->i_mapping);
cond_resched();
}
mutex_unlock(&inode->i_mutex);
out:
*ppos = pos;
current->backing_dev_info = NULL;
return num_written ? num_written : err;
}
static int btrfs_read_actor(read_descriptor_t *desc, struct page *page,
unsigned long offset, unsigned long size)
{
char *kaddr;
unsigned long left, count = desc->count;
if (size > count)
size = count;
if (!PageChecked(page)) {
/* FIXME, do it per block */
struct btrfs_root *root = btrfs_sb(page->mapping->host->i_sb);
int ret = btrfs_csum_verify_file_block(root,
page->mapping->host->i_ino,
page->index << PAGE_CACHE_SHIFT,
kmap(page), PAGE_CACHE_SIZE);
if (ret) {
printk("failed to verify ino %lu page %lu\n",
page->mapping->host->i_ino,
page->index);
memset(page_address(page), 0, PAGE_CACHE_SIZE);
}
SetPageChecked(page);
kunmap(page);
}
/*
* Faults on the destination of a read are common, so do it before
* taking the kmap.
*/
if (!fault_in_pages_writeable(desc->arg.buf, size)) {
kaddr = kmap_atomic(page, KM_USER0);
left = __copy_to_user_inatomic(desc->arg.buf,
kaddr + offset, size);
kunmap_atomic(kaddr, KM_USER0);
if (left == 0)
goto success;
}
/* Do it the slow way */
kaddr = kmap(page);
left = __copy_to_user(desc->arg.buf, kaddr + offset, size);
kunmap(page);
if (left) {
size -= left;
desc->error = -EFAULT;
}
success:
desc->count = count - size;
desc->written += size;
desc->arg.buf += size;
return size;
}
/**
* btrfs_file_aio_read - filesystem read routine
* @iocb: kernel I/O control block
* @iov: io vector request
* @nr_segs: number of segments in the iovec
* @pos: current file position
*/
static ssize_t btrfs_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
unsigned long nr_segs, loff_t pos)
{
struct file *filp = iocb->ki_filp;
ssize_t retval;
unsigned long seg;
size_t count;
loff_t *ppos = &iocb->ki_pos;
count = 0;
for (seg = 0; seg < nr_segs; seg++) {
const struct iovec *iv = &iov[seg];
/*
* If any segment has a negative length, or the cumulative
* length ever wraps negative then return -EINVAL.
*/
count += iv->iov_len;
if (unlikely((ssize_t)(count|iv->iov_len) < 0))
return -EINVAL;
if (access_ok(VERIFY_WRITE, iv->iov_base, iv->iov_len))
continue;
if (seg == 0)
return -EFAULT;
nr_segs = seg;
count -= iv->iov_len; /* This segment is no good */
break;
}
retval = 0;
if (count) {
for (seg = 0; seg < nr_segs; seg++) {
read_descriptor_t desc;
desc.written = 0;
desc.arg.buf = iov[seg].iov_base;
desc.count = iov[seg].iov_len;
if (desc.count == 0)
continue;
desc.error = 0;
do_generic_file_read(filp, ppos, &desc,
btrfs_read_actor);
retval += desc.written;
if (desc.error) {
retval = retval ?: desc.error;
break;
}
}
}
return retval;
}
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;
/*
* Called inside transaction, so use GFP_NOFS
*/
static 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->magic = 0xDEADBEEF;
ei->magic2 = 0xDEADBEAF;
return &ei->vfs_inode;
}
static void btrfs_destroy_inode(struct inode *inode)
{
struct btrfs_inode *ei = BTRFS_I(inode);
WARN_ON(ei->magic != 0xDEADBEEF);
WARN_ON(ei->magic2 != 0xDEADBEAF);
WARN_ON(!list_empty(&inode->i_dentry));
WARN_ON(inode->i_data.nrpages);
ei->magic = 0;
ei->magic2 = 0;
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;
if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
SLAB_CTOR_CONSTRUCTOR) {
inode_init_once(&ei->vfs_inode);
}
}
static int init_inodecache(void)
{
btrfs_inode_cachep = kmem_cache_create("btrfs_inode_cache",
sizeof(struct btrfs_inode),
0, (SLAB_RECLAIM_ACCOUNT|
SLAB_MEM_SPREAD),
init_once, NULL);
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);
btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction_cache",
sizeof(struct btrfs_transaction),
0, (SLAB_RECLAIM_ACCOUNT|
SLAB_MEM_SPREAD),
NULL, NULL);
btrfs_path_cachep = kmem_cache_create("btrfs_path_cache",
sizeof(struct btrfs_transaction),
0, (SLAB_RECLAIM_ACCOUNT|
SLAB_MEM_SPREAD),
NULL, NULL);
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_inode_cachep == NULL || btrfs_trans_handle_cachep == NULL ||
btrfs_transaction_cachep == NULL || btrfs_bit_radix_cachep == NULL)
return -ENOMEM;
return 0;
}
static void destroy_inodecache(void)
{
kmem_cache_destroy(btrfs_inode_cachep);
kmem_cache_destroy(btrfs_trans_handle_cachep);
kmem_cache_destroy(btrfs_transaction_cachep);
kmem_cache_destroy(btrfs_bit_radix_cachep);
kmem_cache_destroy(btrfs_path_cachep);
}
static int btrfs_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data, struct vfsmount *mnt)
{
return get_sb_bdev(fs_type, flags, dev_name, data,
btrfs_fill_super, mnt);
}
static struct file_system_type btrfs_fs_type = {
.owner = THIS_MODULE,
.name = "btrfs",
.get_sb = btrfs_get_sb,
.kill_sb = kill_block_super,
.fs_flags = FS_REQUIRES_DEV,
};
static struct super_operations btrfs_super_ops = {
.statfs = simple_statfs,
.delete_inode = btrfs_delete_inode,
.put_super = btrfs_put_super,
.read_inode = btrfs_read_locked_inode,
.write_super = btrfs_write_super,
.sync_fs = btrfs_sync_fs,
.write_inode = btrfs_write_inode,
.alloc_inode = btrfs_alloc_inode,
.destroy_inode = btrfs_destroy_inode,
};
static struct inode_operations btrfs_dir_inode_operations = {
.lookup = btrfs_lookup,
.create = btrfs_create,
.unlink = btrfs_unlink,
.mkdir = btrfs_mkdir,
.rmdir = btrfs_rmdir,
};
static struct file_operations btrfs_dir_file_operations = {
.llseek = generic_file_llseek,
.read = generic_read_dir,
.readdir = btrfs_readdir,
};
static struct address_space_operations btrfs_aops = {
.readpage = btrfs_readpage,
.readpages = btrfs_readpages,
.writepage = btrfs_writepage,
.sync_page = block_sync_page,
.prepare_write = btrfs_prepare_write,
.commit_write = btrfs_commit_write,
};
static struct inode_operations btrfs_file_inode_operations = {
.truncate = btrfs_truncate,
};
static struct file_operations btrfs_file_operations = {
.llseek = generic_file_llseek,
.read = do_sync_read,
.aio_read = btrfs_file_aio_read,
.write = btrfs_file_write,
.mmap = generic_file_mmap,
.open = generic_file_open,
};
static int __init init_btrfs_fs(void)
{
int err;
printk("btrfs loaded!\n");
err = init_inodecache();
if (err)
return err;
return register_filesystem(&btrfs_fs_type);
}
static void __exit exit_btrfs_fs(void)
{
destroy_inodecache();
unregister_filesystem(&btrfs_fs_type);
printk("btrfs unloaded\n");
}
module_init(init_btrfs_fs)
module_exit(exit_btrfs_fs)
MODULE_LICENSE("GPL");