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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 <linux/statfs.h>
- #include "ctree.h"
- #include "disk-io.h"
- #include "transaction.h"
- #include "btrfs_inode.h"
- #include "ioctl.h"
- void btrfs_fsinfo_release(struct kobject *obj)
- {
- struct btrfs_fs_info *fsinfo = container_of(obj,
- struct btrfs_fs_info, kobj);
- kfree(fsinfo);
- }
- struct kobj_type btrfs_fsinfo_ktype = {
- .release = btrfs_fsinfo_release,
- };
- struct btrfs_iget_args {
- u64 ino;
- struct btrfs_root *root;
- };
- decl_subsys(btrfs, &btrfs_fsinfo_ktype, NULL);
- #define BTRFS_SUPER_MAGIC 0x9123682E
- static struct inode_operations btrfs_dir_inode_operations;
- static struct inode_operations btrfs_dir_ro_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 void btrfs_read_locked_inode(struct inode *inode)
- {
- struct btrfs_path *path;
- struct btrfs_inode_item *inode_item;
- struct btrfs_root *root = BTRFS_I(inode)->root;
- struct btrfs_key location;
- int ret;
- path = btrfs_alloc_path();
- BUG_ON(!path);
- btrfs_init_path(path);
- mutex_lock(&root->fs_info->fs_mutex);
- memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
- ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
- if (ret) {
- btrfs_free_path(path);
- goto make_bad;
- }
- inode_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
- path->slots[0],
- struct btrfs_inode_item);
- inode->i_mode = btrfs_inode_mode(inode_item);
- inode->i_nlink = btrfs_inode_nlink(inode_item);
- inode->i_uid = btrfs_inode_uid(inode_item);
- inode->i_gid = btrfs_inode_gid(inode_item);
- inode->i_size = btrfs_inode_size(inode_item);
- inode->i_atime.tv_sec = btrfs_timespec_sec(&inode_item->atime);
- inode->i_atime.tv_nsec = btrfs_timespec_nsec(&inode_item->atime);
- inode->i_mtime.tv_sec = btrfs_timespec_sec(&inode_item->mtime);
- inode->i_mtime.tv_nsec = btrfs_timespec_nsec(&inode_item->mtime);
- inode->i_ctime.tv_sec = btrfs_timespec_sec(&inode_item->ctime);
- inode->i_ctime.tv_nsec = btrfs_timespec_nsec(&inode_item->ctime);
- inode->i_blocks = btrfs_inode_nblocks(inode_item);
- inode->i_generation = btrfs_inode_generation(inode_item);
- btrfs_free_path(path);
- inode_item = NULL;
- mutex_unlock(&root->fs_info->fs_mutex);
- switch (inode->i_mode & S_IFMT) {
- #if 0
- default:
- init_special_inode(inode, inode->i_mode,
- btrfs_inode_rdev(inode_item));
- break;
- #endif
- case S_IFREG:
- inode->i_mapping->a_ops = &btrfs_aops;
- inode->i_fop = &btrfs_file_operations;
- inode->i_op = &btrfs_file_inode_operations;
- break;
- case S_IFDIR:
- inode->i_fop = &btrfs_dir_file_operations;
- if (root == root->fs_info->tree_root)
- inode->i_op = &btrfs_dir_ro_inode_operations;
- else
- inode->i_op = &btrfs_dir_inode_operations;
- break;
- case S_IFLNK:
- // inode->i_op = &page_symlink_inode_operations;
- 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 int btrfs_unlink_trans(struct btrfs_trans_handle *trans,
- struct btrfs_root *root,
- struct inode *dir,
- struct dentry *dentry)
- {
- struct btrfs_path *path;
- const char *name = dentry->d_name.name;
- int name_len = dentry->d_name.len;
- int ret = 0;
- u64 objectid;
- struct btrfs_dir_item *di;
- path = btrfs_alloc_path();
- BUG_ON(!path);
- btrfs_init_path(path);
- di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
- name, name_len, -1);
- if (IS_ERR(di)) {
- ret = PTR_ERR(di);
- goto err;
- }
- if (!di) {
- ret = -ENOENT;
- goto err;
- }
- objectid = btrfs_disk_key_objectid(&di->location);
- ret = btrfs_delete_one_dir_name(trans, root, path, di);
- BUG_ON(ret);
- btrfs_release_path(root, path);
- di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
- objectid, name, name_len, -1);
- if (IS_ERR(di)) {
- ret = PTR_ERR(di);
- goto err;
- }
- if (!di) {
- ret = -ENOENT;
- goto err;
- }
- ret = btrfs_delete_one_dir_name(trans, root, path, di);
- BUG_ON(ret);
- dentry->d_inode->i_ctime = dir->i_ctime;
- err:
- btrfs_free_path(path);
- if (ret == 0) {
- inode_dec_link_count(dentry->d_inode);
- dir->i_size -= name_len * 2;
- mark_inode_dirty(dir);
- }
- return ret;
- }
- static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
- {
- struct btrfs_root *root;
- struct btrfs_trans_handle *trans;
- int ret;
- root = BTRFS_I(dir)->root;
- mutex_lock(&root->fs_info->fs_mutex);
- trans = btrfs_start_transaction(root, 1);
- 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_I(dir)->root;
- struct btrfs_path *path;
- struct btrfs_key key;
- struct btrfs_trans_handle *trans;
- struct btrfs_key found_key;
- int found_type;
- struct btrfs_leaf *leaf;
- char *goodnames = "..";
- path = btrfs_alloc_path();
- BUG_ON(!path);
- 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 = (u32)-1;
- while(1) {
- ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
- if (ret < 0) {
- err = ret;
- goto out;
- }
- BUG_ON(ret == 0);
- if (path->slots[0] == 0) {
- err = -ENOENT;
- goto out;
- }
- path->slots[0]--;
- leaf = btrfs_buffer_leaf(path->nodes[0]);
- btrfs_disk_key_to_cpu(&found_key,
- &leaf->items[path->slots[0]].key);
- found_type = btrfs_key_type(&found_key);
- if (found_key.objectid != inode->i_ino) {
- err = -ENOENT;
- goto out;
- }
- if ((found_type != BTRFS_DIR_ITEM_KEY &&
- found_type != BTRFS_DIR_INDEX_KEY) ||
- (!btrfs_match_dir_item_name(root, path, goodnames, 2) &&
- !btrfs_match_dir_item_name(root, path, goodnames, 1))) {
- err = -ENOTEMPTY;
- goto out;
- }
- ret = btrfs_del_item(trans, root, path);
- BUG_ON(ret);
- if (found_type == BTRFS_DIR_ITEM_KEY && found_key.offset == 1)
- break;
- btrfs_release_path(root, path);
- }
- ret = 0;
- btrfs_release_path(root, path);
- /* now the directory is empty */
- err = btrfs_unlink_trans(trans, root, dir, dentry);
- if (!err) {
- inode->i_size = 0;
- }
- out:
- btrfs_release_path(root, path);
- btrfs_free_path(path);
- mutex_unlock(&root->fs_info->fs_mutex);
- ret = btrfs_end_transaction(trans, root);
- 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);
- btrfs_init_path(path);
- ret = btrfs_lookup_inode(trans, root, path,
- &BTRFS_I(inode)->location, -1);
- BUG_ON(ret);
- ret = btrfs_del_item(trans, root, path);
- BUG_ON(ret);
- 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;
- /*
- * use BTRFS_CSUM_ITEM_KEY because it is larger than inline keys
- * or extent data
- */
- 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_INLINE_DATA_KEY &&
- btrfs_disk_key_type(found_key) != BTRFS_EXTENT_DATA_KEY)
- break;
- if (btrfs_disk_key_offset(found_key) < inode->i_size)
- break;
- found_extent = 0;
- 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);
- if (btrfs_file_extent_type(fi) !=
- BTRFS_FILE_EXTENT_INLINE) {
- extent_start =
- btrfs_file_extent_disk_blocknr(fi);
- extent_num_blocks =
- btrfs_file_extent_disk_num_blocks(fi);
- /* FIXME blocksize != 4096 */
- inode->i_blocks -=
- btrfs_file_extent_num_blocks(fi) << 3;
- found_extent = 1;
- }
- }
- 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_I(inode)->root;
- int ret;
- truncate_inode_pages(&inode->i_data, 0);
- if (is_bad_inode(inode)) {
- goto no_delete;
- }
- inode->i_size = 0;
- mutex_lock(&root->fs_info->fs_mutex);
- trans = btrfs_start_transaction(root, 1);
- 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,
- struct btrfs_key *location)
- {
- const char *name = dentry->d_name.name;
- int namelen = dentry->d_name.len;
- struct btrfs_dir_item *di;
- struct btrfs_path *path;
- struct btrfs_root *root = BTRFS_I(dir)->root;
- int ret;
- path = btrfs_alloc_path();
- BUG_ON(!path);
- btrfs_init_path(path);
- di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
- namelen, 0);
- if (!di || IS_ERR(di)) {
- location->objectid = 0;
- ret = 0;
- goto out;
- }
- btrfs_disk_key_to_cpu(location, &di->location);
- out:
- btrfs_release_path(root, path);
- btrfs_free_path(path);
- return ret;
- }
- int fixup_tree_root_location(struct btrfs_root *root,
- struct btrfs_key *location,
- struct btrfs_root **sub_root)
- {
- struct btrfs_path *path;
- struct btrfs_root_item *ri;
- if (btrfs_key_type(location) != BTRFS_ROOT_ITEM_KEY)
- return 0;
- if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
- return 0;
- path = btrfs_alloc_path();
- BUG_ON(!path);
- mutex_lock(&root->fs_info->fs_mutex);
- *sub_root = btrfs_read_fs_root(root->fs_info, location);
- if (IS_ERR(*sub_root))
- return PTR_ERR(*sub_root);
- ri = &(*sub_root)->root_item;
- location->objectid = btrfs_root_dirid(ri);
- location->flags = 0;
- btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
- location->offset = 0;
- btrfs_free_path(path);
- mutex_unlock(&root->fs_info->fs_mutex);
- return 0;
- }
- int btrfs_init_locked_inode(struct inode *inode, void *p)
- {
- struct btrfs_iget_args *args = p;
- inode->i_ino = args->ino;
- BTRFS_I(inode)->root = args->root;
- return 0;
- }
- int btrfs_find_actor(struct inode *inode, void *opaque)
- {
- struct btrfs_iget_args *args = opaque;
- return (args->ino == inode->i_ino &&
- args->root == BTRFS_I(inode)->root);
- }
- struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid,
- struct btrfs_root *root)
- {
- struct inode *inode;
- struct btrfs_iget_args args;
- args.ino = objectid;
- args.root = root;
- inode = iget5_locked(s, objectid, btrfs_find_actor,
- btrfs_init_locked_inode,
- (void *)&args);
- return inode;
- }
- static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
- struct nameidata *nd)
- {
- struct inode * inode;
- struct btrfs_inode *bi = BTRFS_I(dir);
- struct btrfs_root *root = bi->root;
- struct btrfs_root *sub_root = root;
- struct btrfs_key location;
- int ret;
- if (dentry->d_name.len > BTRFS_NAME_LEN)
- return ERR_PTR(-ENAMETOOLONG);
- mutex_lock(&root->fs_info->fs_mutex);
- ret = btrfs_inode_by_name(dir, dentry, &location);
- mutex_unlock(&root->fs_info->fs_mutex);
- if (ret < 0)
- return ERR_PTR(ret);
- inode = NULL;
- if (location.objectid) {
- ret = fixup_tree_root_location(root, &location, &sub_root);
- if (ret < 0)
- return ERR_PTR(ret);
- if (ret > 0)
- return ERR_PTR(-ENOENT);
- inode = btrfs_iget_locked(dir->i_sb, location.objectid,
- sub_root);
- if (!inode)
- return ERR_PTR(-EACCES);
- if (inode->i_state & I_NEW) {
- if (sub_root != root) {
- printk("adding new root for inode %lu root %p (found %p)\n", inode->i_ino, sub_root, BTRFS_I(inode)->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 int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
- {
- struct inode *inode = filp->f_path.dentry->d_inode;
- struct btrfs_root *root = BTRFS_I(inode)->root;
- struct btrfs_item *item;
- struct btrfs_dir_item *di;
- struct btrfs_key key;
- struct btrfs_path *path;
- int ret;
- u32 nritems;
- struct btrfs_leaf *leaf;
- int slot;
- int advance;
- unsigned char d_type = DT_UNKNOWN;
- int over = 0;
- u32 di_cur;
- u32 di_total;
- u32 di_len;
- int key_type = BTRFS_DIR_INDEX_KEY;
- /* FIXME, use a real flag for deciding about the key type */
- if (root->fs_info->tree_root == root)
- key_type = BTRFS_DIR_ITEM_KEY;
- mutex_lock(&root->fs_info->fs_mutex);
- key.objectid = inode->i_ino;
- key.flags = 0;
- btrfs_set_key_type(&key, key_type);
- key.offset = filp->f_pos;
- path = btrfs_alloc_path();
- 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) != key_type)
- break;
- if (btrfs_disk_key_offset(&item->key) < filp->f_pos)
- continue;
- filp->f_pos = btrfs_disk_key_offset(&item->key);
- advance = 1;
- di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
- di_cur = 0;
- di_total = btrfs_item_size(leaf->items + slot);
- while(di_cur < di_total) {
- over = filldir(dirent, (const char *)(di + 1),
- btrfs_dir_name_len(di),
- btrfs_disk_key_offset(&item->key),
- btrfs_disk_key_objectid(&di->location),
- d_type);
- if (over)
- goto nopos;
- di_len = btrfs_dir_name_len(di) + sizeof(*di);
- di_cur += di_len;
- di = (struct btrfs_dir_item *)((char *)di + di_len);
- }
- }
- filp->f_pos++;
- nopos:
- ret = 0;
- err:
- btrfs_release_path(root, path);
- btrfs_free_path(path);
- mutex_unlock(&root->fs_info->fs_mutex);
- return ret;
- }
- 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 *tree_root;
- struct btrfs_inode *bi;
- sb->s_maxbytes = MAX_LFS_FILESIZE;
- sb->s_magic = BTRFS_SUPER_MAGIC;
- sb->s_op = &btrfs_super_ops;
- sb->s_time_gran = 1;
- tree_root = open_ctree(sb);
- if (!tree_root) {
- printk("btrfs: open_ctree failed\n");
- return -EIO;
- }
- sb->s_fs_info = tree_root;
- disk_super = tree_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 = btrfs_iget_locked(sb, btrfs_super_root_dir(disk_super),
- tree_root);
- bi = BTRFS_I(inode);
- bi->location.objectid = inode->i_ino;
- bi->location.offset = 0;
- bi->location.flags = 0;
- bi->root = tree_root;
- btrfs_set_key_type(&bi->location, BTRFS_INODE_ITEM_KEY);
- 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);
- }
- 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,
- &BTRFS_I(inode)->location, 1);
- if (ret) {
- if (ret > 0)
- ret = -ENOENT;
- goto failed;
- }
- inode_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
- path->slots[0],
- struct btrfs_inode_item);
- fill_inode_item(inode_item, inode);
- btrfs_mark_buffer_dirty(path->nodes[0]);
- ret = 0;
- failed:
- btrfs_release_path(root, path);
- btrfs_free_path(path);
- return ret;
- }
- static int btrfs_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);
- ret = btrfs_commit_transaction(trans, root);
- mutex_unlock(&root->fs_info->fs_mutex);
- }
- return ret;
- }
- static 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_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, int mode)
- {
- struct inode *inode;
- struct btrfs_inode_item inode_item;
- struct btrfs_key *location;
- int ret;
- inode = new_inode(root->fs_info->sb);
- if (!inode)
- return ERR_PTR(-ENOMEM);
- BTRFS_I(inode)->root = root;
- inode->i_uid = current->fsuid;
- inode->i_gid = current->fsgid;
- inode->i_mode = mode;
- inode->i_ino = objectid;
- inode->i_blocks = 0;
- inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
- fill_inode_item(&inode_item, inode);
- location = &BTRFS_I(inode)->location;
- location->objectid = objectid;
- location->flags = 0;
- location->offset = 0;
- btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
- ret = btrfs_insert_inode(trans, root, objectid, &inode_item);
- BUG_ON(ret);
- insert_inode_hash(inode);
- return inode;
- }
- 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;
- key.objectid = inode->i_ino;
- key.flags = 0;
- btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
- key.offset = 0;
- ret = btrfs_insert_dir_item(trans, root,
- dentry->d_name.name, dentry->d_name.len,
- dentry->d_parent->d_inode->i_ino,
- &key, 0);
- if (ret == 0) {
- dentry->d_parent->d_inode->i_size += dentry->d_name.len * 2;
- ret = btrfs_update_inode(trans, root,
- dentry->d_parent->d_inode);
- }
- return ret;
- }
- static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
- struct dentry *dentry, struct inode *inode)
- {
- int err = btrfs_add_link(trans, dentry, inode);
- if (!err) {
- d_instantiate(dentry, inode);
- return 0;
- }
- if (err > 0)
- err = -EEXIST;
- return err;
- }
- static int btrfs_create(struct inode *dir, struct dentry *dentry,
- int mode, struct nameidata *nd)
- {
- struct btrfs_trans_handle *trans;
- struct btrfs_root *root = BTRFS_I(dir)->root;
- struct inode *inode;
- int err;
- int drop_inode = 0;
- u64 objectid;
- mutex_lock(&root->fs_info->fs_mutex);
- trans = btrfs_start_transaction(root, 1);
- 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, 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);
- if (drop_inode) {
- inode_dec_link_count(inode);
- iput(inode);
- }
- return err;
- }
- static int btrfs_make_empty_dir(struct btrfs_trans_handle *trans,
- struct btrfs_root *root,
- u64 objectid, u64 dirid)
- {
- int ret;
- char buf[2];
- struct btrfs_key key;
- buf[0] = '.';
- buf[1] = '.';
- key.objectid = objectid;
- key.offset = 0;
- key.flags = 0;
- btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
- ret = btrfs_insert_dir_item(trans, root, buf, 1, objectid,
- &key, 1);
- if (ret)
- goto error;
- key.objectid = dirid;
- ret = btrfs_insert_dir_item(trans, root, buf, 2, objectid,
- &key, 1);
- if (ret)
- goto error;
- error:
- return ret;
- }
- static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
- {
- struct inode *inode;
- struct btrfs_trans_handle *trans;
- struct btrfs_root *root = BTRFS_I(dir)->root;
- int err = 0;
- int drop_on_err = 0;
- u64 objectid;
- mutex_lock(&root->fs_info->fs_mutex);
- trans = btrfs_start_transaction(root, 1);
- 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, 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, 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;
- 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_file(struct file *file,
- struct dentry *dentry, int datasync)
- {
- struct inode *inode = dentry->d_inode;
- struct btrfs_root *root = BTRFS_I(inode)->root;
- int ret;
- struct btrfs_trans_handle *trans;
- mutex_lock(&root->fs_info->fs_mutex);
- trans = btrfs_start_transaction(root, 1);
- if (!trans) {
- ret = -ENOMEM;
- goto out;
- }
- ret = btrfs_commit_transaction(trans, root);
- mutex_unlock(&root->fs_info->fs_mutex);
- out:
- return ret > 0 ? EIO : ret;
- }
- 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;
- u32 found_type;
- struct btrfs_path *path;
- struct btrfs_root *root = BTRFS_I(inode)->root;
- struct btrfs_file_extent_item *item;
- struct btrfs_leaf *leaf;
- struct btrfs_disk_key *found_key;
- path = btrfs_alloc_path();
- BUG_ON(!path);
- btrfs_init_path(path);
- if (create) {
- WARN_ON(1);
- }
- ret = btrfs_lookup_file_extent(NULL, 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 out;
- }
- path->slots[0]--;
- }
- item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
- struct btrfs_file_extent_item);
- leaf = btrfs_buffer_leaf(path->nodes[0]);
- blocknr = btrfs_file_extent_disk_blocknr(item);
- blocknr += btrfs_file_extent_offset(item);
- /* are we inside the extent that was found? */
- found_key = &leaf->items[path->slots[0]].key;
- found_type = btrfs_disk_key_type(found_key);
- if (btrfs_disk_key_objectid(found_key) != objectid ||
- found_type != BTRFS_EXTENT_DATA_KEY) {
- extent_end = 0;
- extent_start = 0;
- btrfs_release_path(root, path);
- goto out;
- }
- found_type = btrfs_file_extent_type(item);
- extent_start = btrfs_disk_key_offset(&leaf->items[path->slots[0]].key);
- if (found_type == BTRFS_FILE_EXTENT_REG) {
- extent_start = extent_start >> inode->i_blkbits;
- extent_end = extent_start + btrfs_file_extent_num_blocks(item);
- if (iblock >= extent_start && iblock < extent_end) {
- err = 0;
- btrfs_map_bh_to_logical(root, result, blocknr +
- iblock - extent_start);
- goto out;
- }
- } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
- char *ptr;
- char *map;
- u32 size;
- size = btrfs_file_extent_inline_len(leaf->items +
- path->slots[0]);
- extent_end = (extent_start + size) >> inode->i_blkbits;
- extent_start >>= inode->i_blkbits;
- if (iblock < extent_start || iblock > extent_end) {
- goto out;
- }
- ptr = btrfs_file_extent_inline_start(item);
- map = kmap(result->b_page);
- memcpy(map, ptr, size);
- memset(map + size, 0, PAGE_CACHE_SIZE - size);
- flush_dcache_page(result->b_page);
- kunmap(result->b_page);
- set_buffer_uptodate(result);
- SetPageChecked(result->b_page);
- btrfs_map_bh_to_logical(root, result, 0);
- }
- out:
- btrfs_release_path(root, path);
- btrfs_free_path(path);
- 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_I(inode)->root;
- mutex_lock(&root->fs_info->fs_mutex);
- err = btrfs_get_block_lock(inode, iblock, result, create);
- mutex_unlock(&root->fs_info->fs_mutex);
- return err;
- }
- static int btrfs_prepare_write(struct file *file, struct page *page,
- unsigned from, unsigned to)
- {
- return nobh_prepare_write(page, from, to, btrfs_get_block);
- }
- 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);
- }
- /*
- * While block_write_full_page is writing back the dirty buffers under
- * the page lock, whoever dirtied the buffers may decide to clean them
- * again at any time. We handle that by only looking at the buffer
- * state inside lock_buffer().
- *
- * If block_write_full_page() is called for regular writeback
- * (wbc->sync_mode == WB_SYNC_NONE) then it will redirty a page which has a
- * locked buffer. This only can happen if someone has written the buffer
- * directly, with submit_bh(). At the address_space level PageWriteback
- * prevents this contention from occurring.
- */
- static int __btrfs_write_full_page(struct inode *inode, struct page *page,
- struct writeback_control *wbc)
- {
- int err;
- sector_t block;
- sector_t last_block;
- struct buffer_head *bh, *head;
- const unsigned blocksize = 1 << inode->i_blkbits;
- int nr_underway = 0;
- BUG_ON(!PageLocked(page));
- last_block = (i_size_read(inode) - 1) >> inode->i_blkbits;
- if (!page_has_buffers(page)) {
- create_empty_buffers(page, blocksize,
- (1 << BH_Dirty)|(1 << BH_Uptodate));
- }
- /*
- * Be very careful. We have no exclusion from __set_page_dirty_buffers
- * here, and the (potentially unmapped) buffers may become dirty at
- * any time. If a buffer becomes dirty here after we've inspected it
- * then we just miss that fact, and the page stays dirty.
- *
- * Buffers outside i_size may be dirtied by __set_page_dirty_buffers;
- * handle that here by just cleaning them.
- */
- block = (sector_t)page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
- head = page_buffers(page);
- bh = head;
- /*
- * Get all the dirty buffers mapped to disk addresses and
- * handle any aliases from the underlying blockdev's mapping.
- */
- do {
- if (block > last_block) {
- /*
- * mapped buffers outside i_size will occur, because
- * this page can be outside i_size when there is a
- * truncate in progress.
- */
- /*
- * The buffer was zeroed by block_write_full_page()
- */
- clear_buffer_dirty(bh);
- set_buffer_uptodate(bh);
- } else if (!buffer_mapped(bh) && buffer_dirty(bh)) {
- WARN_ON(bh->b_size != blocksize);
- err = btrfs_get_block(inode, block, bh, 0);
- if (err)
- goto recover;
- if (buffer_new(bh)) {
- /* blockdev mappings never come here */
- clear_buffer_new(bh);
- unmap_underlying_metadata(bh->b_bdev,
- bh->b_blocknr);
- }
- }
- bh = bh->b_this_page;
- block++;
- } while (bh != head);
- do {
- if (!buffer_mapped(bh))
- continue;
- /*
- * If it's a fully non-blocking write attempt and we cannot
- * lock the buffer then redirty the page. Note that this can
- * potentially cause a busy-wait loop from pdflush and kswapd
- * activity, but those code paths have their own higher-level
- * throttling.
- */
- if (wbc->sync_mode != WB_SYNC_NONE || !wbc->nonblocking) {
- lock_buffer(bh);
- } else if (test_set_buffer_locked(bh)) {
- redirty_page_for_writepage(wbc, page);
- continue;
- }
- if (test_clear_buffer_dirty(bh) && bh->b_blocknr != 0) {
- mark_buffer_async_write(bh);
- } else {
- unlock_buffer(bh);
- }
- } while ((bh = bh->b_this_page) != head);
- /*
- * The page and its buffers are protected by PageWriteback(), so we can
- * drop the bh refcounts early.
- */
- BUG_ON(PageWriteback(page));
- set_page_writeback(page);
- do {
- struct buffer_head *next = bh->b_this_page;
- if (buffer_async_write(bh)) {
- submit_bh(WRITE, bh);
- nr_underway++;
- }
- bh = next;
- } while (bh != head);
- unlock_page(page);
- err = 0;
- done:
- if (nr_underway == 0) {
- /*
- * The page was marked dirty, but the buffers were
- * clean. Someone wrote them back by hand with
- * ll_rw_block/submit_bh. A rare case.
- */
- int uptodate = 1;
- do {
- if (!buffer_uptodate(bh)) {
- uptodate = 0;
- break;
- }
- bh = bh->b_this_page;
- } while (bh != head);
- if (uptodate)
- SetPageUptodate(page);
- end_page_writeback(page);
- /*
- * The page and buffer_heads can be released at any time from
- * here on.
- */
- wbc->pages_skipped++; /* We didn't write this page */
- }
- return err;
- recover:
- /*
- * ENOSPC, or some other error. We may already have added some
- * blocks to the file, so we need to write these out to avoid
- * exposing stale data.
- * The page is currently locked and not marked for writeback
- */
- bh = head;
- /* Recovery: lock and submit the mapped buffers */
- do {
- if (buffer_mapped(bh) && buffer_dirty(bh)) {
- lock_buffer(bh);
- mark_buffer_async_write(bh);
- } else {
- /*
- * The buffer may have been set dirty during
- * attachment to a dirty page.
- */
- clear_buffer_dirty(bh);
- }
- } while ((bh = bh->b_this_page) != head);
- SetPageError(page);
- BUG_ON(PageWriteback(page));
- set_page_writeback(page);
- do {
- struct buffer_head *next = bh->b_this_page;
- if (buffer_async_write(bh)) {
- clear_buffer_dirty(bh);
- submit_bh(WRITE, bh);
- nr_underway++;
- }
- bh = next;
- } while (bh != head);
- unlock_page(page);
- goto done;
- }
- /*
- * The generic ->writepage function for buffer-backed address_spaces
- */
- static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
- {
- struct inode * const inode = page->mapping->host;
- loff_t i_size = i_size_read(inode);
- const pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
- unsigned offset;
- void *kaddr;
- /* Is the page fully inside i_size? */
- if (page->index < end_index)
- return __btrfs_write_full_page(inode, page, wbc);
- /* Is the page fully outside i_size? (truncate in progress) */
- offset = i_size & (PAGE_CACHE_SIZE-1);
- if (page->index >= end_index+1 || !offset) {
- /*
- * The page may have dirty, unmapped buffers. For example,
- * they may have been added in ext3_writepage(). Make them
- * freeable here, so the page does not leak.
- */
- block_invalidatepage(page, 0);
- unlock_page(page);
- return 0; /* don't care */
- }
- /*
- * The page straddles i_size. It must be zeroed out on each and every
- * writepage invokation because it may be mmapped. "A file is mapped
- * in multiples of the page size. For a file that is not a multiple of
- * the page size, the remaining memory is zeroed when mapped, and
- * writes to that region are not written out to the file."
- */
- kaddr = kmap_atomic(page, KM_USER0);
- memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset);
- flush_dcache_page(page);
- kunmap_atomic(kaddr, KM_USER0);
- return __btrfs_write_full_page(inode, page, wbc);
- }
- static void btrfs_truncate(struct inode *inode)
- {
- struct btrfs_root *root = BTRFS_I(inode)->root;
- int ret;
- struct btrfs_trans_handle *trans;
- if (!S_ISREG(inode->i_mode))
- return;
- if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
- return;
- 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);
- }
- /*
- * Make sure any changes to nobh_commit_write() are reflected in
- * nobh_truncate_page(), since it doesn't call commit_write().
- */
- static int btrfs_commit_write(struct file *file, struct page *page,
- unsigned from, unsigned to)
- {
- struct inode *inode = page->mapping->host;
- struct buffer_head *bh;
- loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
- SetPageUptodate(page);
- bh = page_buffers(page);
- if (buffer_mapped(bh) && bh->b_blocknr != 0) {
- set_page_dirty(page);
- }
- if (pos > inode->i_size) {
- i_size_write(inode, pos);
- mark_inode_dirty(inode);
- }
- return 0;
- }
- static int 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;
- struct buffer_head *bh;
- struct btrfs_file_extent_item *ei;
- 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);
- bh = page_buffers(pages[i]);
- if (buffer_mapped(bh) && bh->b_blocknr == 0) {
- struct btrfs_key key;
- struct btrfs_path *path;
- char *ptr;
- u32 datasize;
- path = btrfs_alloc_path();
- BUG_ON(!path);
- key.objectid = inode->i_ino;
- key.offset = pages[i]->index << PAGE_CACHE_SHIFT;
- key.flags = 0;
- btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
- BUG_ON(write_bytes >= PAGE_CACHE_SIZE);
- datasize = offset +
- btrfs_file_extent_calc_inline_size(write_bytes);
- ret = btrfs_insert_empty_item(trans, root, path, &key,
- datasize);
- BUG_ON(ret);
- ei = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
- path->slots[0], struct btrfs_file_extent_item);
- btrfs_set_file_extent_generation(ei, trans->transid);
- btrfs_set_file_extent_type(ei,
- BTRFS_FILE_EXTENT_INLINE);
- ptr = btrfs_file_extent_inline_start(ei);
- memcpy(ptr, bh->b_data, offset + write_bytes);
- mark_buffer_dirty(path->nodes[0]);
- btrfs_free_path(path);
- } else {
- 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 = btrfs_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 drop_extents(struct btrfs_trans_handle *trans,
- struct btrfs_root *root,
- struct inode *inode,
- u64 start, u64 end)
- {
- int ret;
- struct btrfs_key key;
- struct btrfs_leaf *leaf;
- int slot;
- struct btrfs_file_extent_item *extent;
- u64 extent_end = 0;
- int keep;
- struct btrfs_file_extent_item old;
- struct btrfs_path *path;
- u64 search_start = start;
- int bookend;
- int found_type;
- int found_extent;
- int found_inline;
- path = btrfs_alloc_path();
- if (!path)
- return -ENOMEM;
- while(1) {
- btrfs_release_path(root, path);
- ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino,
- search_start, -1);
- if (ret < 0)
- goto out;
- if (ret > 0) {
- if (path->slots[0] == 0) {
- ret = 0;
- goto out;
- }
- path->slots[0]--;
- }
- keep = 0;
- bookend = 0;
- found_extent = 0;
- found_inline = 0;
- extent = NULL;
- leaf = btrfs_buffer_leaf(path->nodes[0]);
- slot = path->slots[0];
- btrfs_disk_key_to_cpu(&key, &leaf->items[slot].key);
- if (key.offset >= end || key.objectid != inode->i_ino) {
- ret = 0;
- goto out;
- }
- if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY) {
- ret = 0;
- goto out;
- }
- extent = btrfs_item_ptr(leaf, slot,
- struct btrfs_file_extent_item);
- found_type = btrfs_file_extent_type(extent);
- if (found_type == BTRFS_FILE_EXTENT_REG) {
- extent_end = key.offset +
- (btrfs_file_extent_num_blocks(extent) <<
- inode->i_blkbits);
- found_extent = 1;
- } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
- found_inline = 1;
- extent_end = key.offset +
- btrfs_file_extent_inline_len(leaf->items + slot);
- }
- if (!found_extent && !found_inline) {
- ret = 0;
- goto out;
- }
- if (search_start >= extent_end) {
- ret = 0;
- goto out;
- }
- search_start = extent_end;
- if (end < extent_end && end >= key.offset) {
- if (found_extent) {
- memcpy(&old, extent, sizeof(old));
- ret = btrfs_inc_extent_ref(trans, root,
- btrfs_file_extent_disk_blocknr(&old),
- btrfs_file_extent_disk_num_blocks(&old));
- BUG_ON(ret);
- }
- WARN_ON(found_inline);
- bookend = 1;
- }
- if (start > key.offset) {
- u64 new_num;
- u64 old_num;
- /* truncate existing extent */
- keep = 1;
- WARN_ON(start & (root->blocksize - 1));
- if (found_extent) {
- new_num = (start - key.offset) >>
- inode->i_blkbits;
- old_num = btrfs_file_extent_num_blocks(extent);
- inode->i_blocks -= (old_num - new_num) << 3;
- btrfs_set_file_extent_num_blocks(extent,
- new_num);
- mark_buffer_dirty(path->nodes[0]);
- } else {
- WARN_ON(1);
- /*
- ret = btrfs_truncate_item(trans, root, path,
- start - key.offset);
- BUG_ON(ret);
- */
- }
- }
- if (!keep) {
- u64 disk_blocknr = 0;
- u64 disk_num_blocks = 0;
- u64 extent_num_blocks = 0;
- if (found_extent) {
- disk_blocknr =
- btrfs_file_extent_disk_blocknr(extent);
- disk_num_blocks =
- btrfs_file_extent_disk_num_blocks(extent);
- extent_num_blocks =
- btrfs_file_extent_num_blocks(extent);
- }
- ret = btrfs_del_item(trans, root, path);
- BUG_ON(ret);
- btrfs_release_path(root, path);
- if (found_extent) {
- inode->i_blocks -=
- btrfs_file_extent_num_blocks(extent) << 3;
- ret = btrfs_free_extent(trans, root,
- disk_blocknr,
- disk_num_blocks, 0);
- }
- BUG_ON(ret);
- if (!bookend && search_start >= end) {
- ret = 0;
- goto out;
- }
- if (!bookend)
- continue;
- }
- if (bookend && found_extent) {
- /* create bookend */
- struct btrfs_key ins;
- ins.objectid = inode->i_ino;
- ins.offset = end;
- ins.flags = 0;
- btrfs_set_key_type(&ins, BTRFS_EXTENT_DATA_KEY);
- btrfs_release_path(root, path);
- ret = btrfs_insert_empty_item(trans, root, path, &ins,
- sizeof(*extent));
- BUG_ON(ret);
- extent = btrfs_item_ptr(
- btrfs_buffer_leaf(path->nodes[0]),
- path->slots[0],
- struct btrfs_file_extent_item);
- btrfs_set_file_extent_disk_blocknr(extent,
- btrfs_file_extent_disk_blocknr(&old));
- btrfs_set_file_extent_disk_num_blocks(extent,
- btrfs_file_extent_disk_num_blocks(&old));
- btrfs_set_file_extent_offset(extent,
- btrfs_file_extent_offset(&old) +
- ((end - key.offset) >> inode->i_blkbits));
- WARN_ON(btrfs_file_extent_num_blocks(&old) <
- (end - key.offset) >> inode->i_blkbits);
- btrfs_set_file_extent_num_blocks(extent,
- btrfs_file_extent_num_blocks(&old) -
- ((end - key.offset) >> inode->i_blkbits));
- btrfs_set_file_extent_type(extent,
- BTRFS_FILE_EXTENT_REG);
- btrfs_set_file_extent_generation(extent,
- btrfs_file_extent_generation(&old));
- btrfs_mark_buffer_dirty(path->nodes[0]);
- inode->i_blocks +=
- btrfs_file_extent_num_blocks(extent) << 3;
- ret = 0;
- goto out;
- }
- }
- out:
- btrfs_free_path(path);
- return ret;
- }
- static int prepare_pages(struct btrfs_root *root,
- struct file *file,
- struct page **pages,
- size_t num_pages,
- loff_t pos,
- unsigned long first_index,
- unsigned long last_index,
- size_t write_bytes,
- u64 alloc_extent_start)
- {
- int i;
- unsigned long index = pos >> PAGE_CACHE_SHIFT;
- struct inode *inode = file->f_path.dentry->d_inode;
- int offset;
- int err = 0;
- int this_write;
- struct buffer_head *bh;
- struct buffer_head *head;
- 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);
- create_empty_buffers(pages[i], root->fs_info->sb->s_blocksize,
- (1 << BH_Uptodate));
- head = page_buffers(pages[i]);
- bh = head;
- do {
- err = btrfs_map_bh_to_logical(root, bh,
- alloc_extent_start);
- BUG_ON(err);
- if (err)
- goto failed_truncate;
- bh = bh->b_this_page;
- if (alloc_extent_start)
- alloc_extent_start++;
- } while (bh != head);
- pos += this_write;
- 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_I(inode)->root;
- struct page *pages[8];
- struct page *pinned[2] = { NULL, NULL };
- unsigned long first_index;
- unsigned long last_index;
- u64 start_pos;
- u64 num_blocks;
- u64 alloc_extent_start;
- struct btrfs_trans_handle *trans;
- struct btrfs_key ins;
- 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);
- start_pos = pos & ~((u64)PAGE_CACHE_SIZE - 1);
- num_blocks = (count + pos - start_pos + root->blocksize - 1) >>
- inode->i_blkbits;
- mutex_lock(&inode->i_mutex);
- first_index = pos >> PAGE_CACHE_SHIFT;
- last_index = (pos + count) >> PAGE_CACHE_SHIFT;
- if ((first_index << PAGE_CACHE_SHIFT) < inode->i_size &&
- (pos & (PAGE_CACHE_SIZE - 1))) {
- pinned[0] = grab_cache_page(inode->i_mapping, first_index);
- if (!PageUptodate(pinned[0])) {
- ret = mpage_readpage(pinned[0], btrfs_get_block);
- BUG_ON(ret);
- } else {
- unlock_page(pinned[0]);
- }
- }
- if (first_index != last_index &&
- (last_index << PAGE_CACHE_SHIFT) < inode->i_size &&
- (count & (PAGE_CACHE_SIZE - 1))) {
- pinned[1] = grab_cache_page(inode->i_mapping, last_index);
- if (!PageUptodate(pinned[1])) {
- ret = mpage_readpage(pinned[1], btrfs_get_block);
- BUG_ON(ret);
- } else {
- unlock_page(pinned[1]);
- }
- }
- mutex_lock(&root->fs_info->fs_mutex);
- trans = btrfs_start_transaction(root, 1);
- if (!trans) {
- err = -ENOMEM;
- mutex_unlock(&root->fs_info->fs_mutex);
- goto out_unlock;
- }
- /* FIXME blocksize != 4096 */
- inode->i_blocks += num_blocks << 3;
- if (start_pos < inode->i_size) {
- /* FIXME blocksize != pagesize */
- ret = drop_extents(trans, root, inode,
- start_pos,
- (pos + count + root->blocksize -1) &
- ~((u64)root->blocksize - 1));
- BUG_ON(ret);
- }
- if (inode->i_size >= PAGE_CACHE_SIZE || pos + count < inode->i_size ||
- pos + count - start_pos > BTRFS_MAX_INLINE_DATA_SIZE(root)) {
- ret = btrfs_alloc_extent(trans, root, inode->i_ino,
- num_blocks, 1, (u64)-1, &ins);
- BUG_ON(ret);
- ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
- start_pos, ins.objectid, ins.offset);
- BUG_ON(ret);
- } else {
- ins.offset = 0;
- ins.objectid = 0;
- }
- BUG_ON(ret);
- alloc_extent_start = ins.objectid;
- ret = btrfs_end_transaction(trans, root);
- mutex_unlock(&root->fs_info->fs_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;
- memset(pages, 0, sizeof(pages));
- ret = prepare_pages(root, file, pages, num_pages,
- pos, first_index, last_index,
- write_bytes, alloc_extent_start);
- BUG_ON(ret);
- /* FIXME blocks != pagesize */
- if (alloc_extent_start)
- alloc_extent_start += num_pages;
- 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();
- }
- out_unlock:
- mutex_unlock(&inode->i_mutex);
- out:
- if (pinned[0])
- page_cache_release(pinned[0]);
- if (pinned[1])
- page_cache_release(pinned[1]);
- *ppos = pos;
- current->backing_dev_info = NULL;
- mark_inode_dirty(inode);
- 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;
- struct inode *inode = page->mapping->host;
- if (size > count)
- size = count;
- if (!PageChecked(page)) {
- /* FIXME, do it per block */
- struct btrfs_root *root = BTRFS_I(inode)->root;
- 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 int create_subvol(struct btrfs_root *root, char *name, int namelen)
- {
- struct btrfs_trans_handle *trans;
- struct btrfs_key key;
- struct btrfs_root_item root_item;
- struct btrfs_inode_item *inode_item;
- struct buffer_head *subvol;
- struct btrfs_leaf *leaf;
- struct btrfs_root *new_root;
- struct inode *inode;
- int ret;
- u64 objectid;
- u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
- mutex_lock(&root->fs_info->fs_mutex);
- trans = btrfs_start_transaction(root, 1);
- BUG_ON(!trans);
- subvol = btrfs_alloc_free_block(trans, root);
- if (subvol == NULL)
- return -ENOSPC;
- leaf = btrfs_buffer_leaf(subvol);
- btrfs_set_header_nritems(&leaf->header, 0);
- btrfs_set_header_level(&leaf->header, 0);
- btrfs_set_header_blocknr(&leaf->header, bh_blocknr(subvol));
- btrfs_set_header_generation(&leaf->header, trans->transid);
- btrfs_set_header_owner(&leaf->header, root->root_key.objectid);
- memcpy(leaf->header.fsid, root->fs_info->disk_super->fsid,
- sizeof(leaf->header.fsid));
- mark_buffer_dirty(subvol);
- inode_item = &root_item.inode;
- memset(inode_item, 0, sizeof(*inode_item));
- btrfs_set_inode_generation(inode_item, 1);
- btrfs_set_inode_size(inode_item, 3);
- btrfs_set_inode_nlink(inode_item, 1);
- btrfs_set_inode_nblocks(inode_item, 1);
- btrfs_set_inode_mode(inode_item, S_IFDIR | 0755);
- btrfs_set_root_blocknr(&root_item, bh_blocknr(subvol));
- btrfs_set_root_refs(&root_item, 1);
- brelse(subvol);
- subvol = NULL;
- ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
- 0, &objectid);
- BUG_ON(ret);
- btrfs_set_root_dirid(&root_item, new_dirid);
- key.objectid = objectid;
- key.offset = 1;
- key.flags = 0;
- btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
- ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
- &root_item);
- BUG_ON(ret);
- /*
- * 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, 0);
- BUG_ON(ret);
- ret = btrfs_commit_transaction(trans, root);
- BUG_ON(ret);
- new_root = btrfs_read_fs_root(root->fs_info, &key);
- BUG_ON(!new_root);
- trans = btrfs_start_transaction(new_root, 1);
- BUG_ON(!trans);
- inode = btrfs_new_inode(trans, new_root, new_dirid, S_IFDIR | 0700);
- inode->i_op = &btrfs_dir_inode_operations;
- inode->i_fop = &btrfs_dir_file_operations;
- ret = btrfs_make_empty_dir(trans, new_root, new_dirid, new_dirid);
- BUG_ON(ret);
- inode->i_nlink = 1;
- inode->i_size = 6;
- ret = btrfs_update_inode(trans, new_root, inode);
- BUG_ON(ret);
- ret = btrfs_commit_transaction(trans, new_root);
- BUG_ON(ret);
- iput(inode);
- mutex_unlock(&root->fs_info->fs_mutex);
- return 0;
- }
- static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
- {
- struct btrfs_trans_handle *trans;
- struct btrfs_key key;
- struct btrfs_root_item new_root_item;
- int ret;
- u64 objectid;
- if (!root->ref_cows)
- return -EINVAL;
- mutex_lock(&root->fs_info->fs_mutex);
- trans = btrfs_start_transaction(root, 1);
- BUG_ON(!trans);
- ret = btrfs_update_inode(trans, root, root->inode);
- BUG_ON(ret);
- ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
- 0, &objectid);
- BUG_ON(ret);
- memcpy(&new_root_item, &root->root_item,
- sizeof(new_root_item));
- key.objectid = objectid;
- key.offset = 1;
- key.flags = 0;
- btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
- btrfs_set_root_blocknr(&new_root_item, bh_blocknr(root->node));
- ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
- &new_root_item);
- BUG_ON(ret);
- /*
- * 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, 0);
- BUG_ON(ret);
- ret = btrfs_inc_root_ref(trans, root);
- BUG_ON(ret);
- ret = btrfs_commit_transaction(trans, root);
- BUG_ON(ret);
- mutex_unlock(&root->fs_info->fs_mutex);
- return 0;
- }
- static int add_disk(struct btrfs_root *root, char *name, int namelen)
- {
- struct block_device *bdev;
- struct btrfs_path *path;
- struct super_block *sb = root->fs_info->sb;
- struct btrfs_root *dev_root = root->fs_info->dev_root;
- struct btrfs_trans_handle *trans;
- struct btrfs_device_item *dev_item;
- struct btrfs_key key;
- u16 item_size;
- u64 num_blocks;
- u64 new_blocks;
- u64 device_id;
- int ret;
- printk("adding disk %s\n", name);
- path = btrfs_alloc_path();
- if (!path)
- return -ENOMEM;
- num_blocks = btrfs_super_total_blocks(root->fs_info->disk_super);
- bdev = open_bdev_excl(name, O_RDWR, sb);
- if (IS_ERR(bdev)) {
- ret = PTR_ERR(bdev);
- printk("open bdev excl failed ret %d\n", ret);
- goto out_nolock;
- }
- set_blocksize(bdev, sb->s_blocksize);
- new_blocks = bdev->bd_inode->i_size >> sb->s_blocksize_bits;
- key.objectid = num_blocks;
- key.offset = new_blocks;
- key.flags = 0;
- btrfs_set_key_type(&key, BTRFS_DEV_ITEM_KEY);
- mutex_lock(&dev_root->fs_info->fs_mutex);
- trans = btrfs_start_transaction(dev_root, 1);
- item_size = sizeof(*dev_item) + namelen;
- printk("insert empty on %Lu %Lu %u size %d\n", num_blocks, new_blocks, key.flags, item_size);
- ret = btrfs_insert_empty_item(trans, dev_root, path, &key, item_size);
- if (ret) {
- printk("insert failed %d\n", ret);
- close_bdev_excl(bdev);
- if (ret > 0)
- ret = -EEXIST;
- goto out;
- }
- dev_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
- path->slots[0], struct btrfs_device_item);
- btrfs_set_device_pathlen(dev_item, namelen);
- memcpy(dev_item + 1, name, namelen);
- device_id = btrfs_super_last_device_id(root->fs_info->disk_super) + 1;
- btrfs_set_super_last_device_id(root->fs_info->disk_super, device_id);
- btrfs_set_device_id(dev_item, device_id);
- mark_buffer_dirty(path->nodes[0]);
- ret = btrfs_insert_dev_radix(root, bdev, device_id, num_blocks,
- new_blocks);
- if (!ret) {
- btrfs_set_super_total_blocks(root->fs_info->disk_super,
- num_blocks + new_blocks);
- i_size_write(root->fs_info->btree_inode,
- (num_blocks + new_blocks) <<
- root->fs_info->btree_inode->i_blkbits);
- }
- out:
- ret = btrfs_commit_transaction(trans, dev_root);
- BUG_ON(ret);
- mutex_unlock(&root->fs_info->fs_mutex);
- out_nolock:
- btrfs_free_path(path);
- return ret;
- }
- static int btrfs_ioctl(struct inode *inode, struct file *filp, unsigned int
- cmd, unsigned long arg)
- {
- struct btrfs_root *root = BTRFS_I(inode)->root;
- struct btrfs_ioctl_vol_args vol_args;
- int ret = 0;
- struct btrfs_dir_item *di;
- int namelen;
- struct btrfs_path *path;
- u64 root_dirid;
- switch (cmd) {
- case BTRFS_IOC_SNAP_CREATE:
- if (copy_from_user(&vol_args,
- (struct btrfs_ioctl_vol_args __user *)arg,
- sizeof(vol_args)))
- return -EFAULT;
- namelen = strlen(vol_args.name);
- if (namelen > BTRFS_VOL_NAME_MAX)
- return -EINVAL;
- 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 (root == root->fs_info->tree_root)
- ret = create_subvol(root, vol_args.name, namelen);
- else
- ret = create_snapshot(root, vol_args.name, namelen);
- WARN_ON(ret);
- break;
- case BTRFS_IOC_ADD_DISK:
- if (copy_from_user(&vol_args,
- (struct btrfs_ioctl_vol_args __user *)arg,
- sizeof(vol_args)))
- return -EFAULT;
- namelen = strlen(vol_args.name);
- if (namelen > BTRFS_VOL_NAME_MAX)
- return -EINVAL;
- vol_args.name[namelen] = '\0';
- ret = add_disk(root, vol_args.name, namelen);
- break;
- default:
- return -ENOTTY;
- }
- return ret;
- }
- 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;
- return &ei->vfs_inode;
- }
- static void btrfs_destroy_inode(struct inode *inode)
- {
- WARN_ON(!list_empty(&inode->i_dentry));
- WARN_ON(inode->i_data.nrpages);
- kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
- }
- static void init_once(void * foo, struct kmem_cache * cachep,
- unsigned long flags)
- {
- struct btrfs_inode *ei = (struct btrfs_inode *) foo;
- 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 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_statfs(struct dentry *dentry, struct kstatfs *buf)
- {
- struct btrfs_root *root = btrfs_sb(dentry->d_sb);
- struct btrfs_super_block *disk_super = root->fs_info->disk_super;
- buf->f_namelen = BTRFS_NAME_LEN;
- buf->f_blocks = btrfs_super_total_blocks(disk_super);
- buf->f_bfree = buf->f_blocks - btrfs_super_blocks_used(disk_super);
- buf->f_bavail = buf->f_bfree;
- buf->f_bsize = dentry->d_sb->s_blocksize;
- buf->f_type = BTRFS_SUPER_MAGIC;
- return 0;
- }
- 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 = {
- .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,
- .dirty_inode = btrfs_dirty_inode,
- .alloc_inode = btrfs_alloc_inode,
- .destroy_inode = btrfs_destroy_inode,
- .statfs = btrfs_statfs,
- };
- 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 inode_operations btrfs_dir_ro_inode_operations = {
- .lookup = btrfs_lookup,
- };
- static struct file_operations btrfs_dir_file_operations = {
- .llseek = generic_file_llseek,
- .read = generic_read_dir,
- .readdir = btrfs_readdir,
- .ioctl = btrfs_ioctl,
- };
- static struct address_space_operations btrfs_aops = {
- .readpage = btrfs_readpage,
- .writepage = btrfs_writepage,
- .sync_page = block_sync_page,
- .prepare_write = btrfs_prepare_write,
- .commit_write = btrfs_commit_write,
- };
- static struct inode_operations btrfs_file_inode_operations = {
- .truncate = btrfs_truncate,
- .getattr = btrfs_getattr,
- };
- 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,
- .ioctl = btrfs_ioctl,
- .fsync = btrfs_sync_file,
- };
- static int __init init_btrfs_fs(void)
- {
- int err;
- printk("btrfs loaded!\n");
- err = init_inodecache();
- if (err)
- return err;
- kset_set_kset_s(&btrfs_subsys, fs_subsys);
- err = subsystem_register(&btrfs_subsys);
- if (err)
- goto out;
- return register_filesystem(&btrfs_fs_type);
- out:
- destroy_inodecache();
- return err;
- }
- static void __exit exit_btrfs_fs(void)
- {
- destroy_inodecache();
- unregister_filesystem(&btrfs_fs_type);
- subsystem_unregister(&btrfs_subsys);
- printk("btrfs unloaded\n");
- }
- module_init(init_btrfs_fs)
- module_exit(exit_btrfs_fs)
- MODULE_LICENSE("GPL");
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