Btrfs: directory inode index is back (7e38180e) · Commits · e / devices / android_kernel_oneplus_sm7250

fs/btrfs/TODO

+2 −2

Original line number	Diff line number	Diff line
		* cleanup, add more error checking, get rid of BUG_ONs
		* Fix ENOSPC handling
		* Add block mapping tree (simple dm layer)
		* Make allocator smarter
		* add a block group to struct inode
		* Make sure nobh stuff is working properly for cows
		* Do actual block accounting
		* Check compat and incompat flags on the inode
		* Get rid of struct ctree_path, limiting tree levels held at one time
		* Add generation number to key pointer in nodes
		* Add parent pointer back to extent map.
		* Release
		* Do real tree locking
		* Add extent mirroring (backup copies of blocks)

fs/btrfs/ctree.h

+17 −41

Original line number	Diff line number	Diff line
		@@ -185,11 +185,6 @@ struct btrfs_inode_item {
		struct btrfs_inode_timespec otime;
		} __attribute__ ((__packed__));

		/* inline data is just a blob of bytes */
		struct btrfs_inline_data_item {
		u8 data;
		} __attribute__ ((__packed__));

		struct btrfs_dir_item {
		struct btrfs_disk_key location;
		__le16 flags;
		@@ -293,9 +288,6 @@ struct btrfs_root {
		#define BTRFS_KEY_TYPE_MASK (((u32)BTRFS_KEY_TYPE_MAX - 1) << \
		BTRFS_KEY_TYPE_SHIFT)

		#define BTRFS_KEY_OVERFLOW_MAX 128
		#define BTRFS_KEY_OVERFLOW_MASK ((u32)BTRFS_KEY_OVERFLOW_MAX - 1)

		/*
		* inode items have the data typically returned from stat and store other
		* info about object characteristics. There is one for every file and dir in
		@@ -621,31 +613,6 @@ static inline void btrfs_set_key_type(struct btrfs_key *key, u32 val)
		key->flags = (key->flags & ~(BTRFS_KEY_TYPE_MASK)) \| val;
		}

		static inline u32 btrfs_key_overflow(struct btrfs_key *key)
		{
		return key->flags & BTRFS_KEY_OVERFLOW_MASK;
		}

		static inline void btrfs_set_key_overflow(struct btrfs_key *key, u32 over)
		{
		BUG_ON(over >= BTRFS_KEY_OVERFLOW_MAX);
		key->flags = (key->flags & ~BTRFS_KEY_OVERFLOW_MASK) \| over;
		}

		static inline u32 btrfs_disk_key_overflow(struct btrfs_disk_key *key)
		{
		return le32_to_cpu(key->flags) & BTRFS_KEY_OVERFLOW_MASK;
		}

		static inline void btrfs_set_disk_key_overflow(struct btrfs_disk_key *key,
		u32 over)
		{
		u32 flags = btrfs_disk_key_flags(key);
		BUG_ON(over >= BTRFS_KEY_OVERFLOW_MAX);
		flags = (flags & ~BTRFS_KEY_OVERFLOW_MASK) \| over;
		btrfs_set_disk_key_flags(key, flags);
		}

		static inline u64 btrfs_header_blocknr(struct btrfs_header *h)
		{
		return le64_to_cpu(h->blocknr);
		@@ -1079,15 +1046,24 @@ int btrfs_find_last_root(struct btrfs_root *root, u64 objectid, struct
		int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
		root, const char name, int name_len, u64 dir,
		struct btrfs_key *location, u8 type);
		int btrfs_lookup_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
		root, struct btrfs_path path, u64 dir,
		const char *name, int name_len, int mod);
		int btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
		struct btrfs_dir_item btrfs_lookup_dir_item(struct btrfs_trans_handle trans,
		struct btrfs_root *root,
		struct btrfs_path *path, u64 dir,
		u64 objectid, int mod);
		int btrfs_match_dir_item_name(struct btrfs_root root, struct btrfs_path path,
		const char *name, int name_len,
		int mod);
		struct btrfs_dir_item *
		btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
		struct btrfs_root *root,
		struct btrfs_path *path, u64 dir,
		u64 objectid, const char *name, int name_len,
		int mod);
		struct btrfs_dir_item btrfs_match_dir_item_name(struct btrfs_root root,
		struct btrfs_path *path,
		const char *name, int name_len);
		int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans,
		struct btrfs_root *root,
		struct btrfs_path *path,
		struct btrfs_dir_item *di);
		/* inode-map.c */
		int btrfs_find_free_objectid(struct btrfs_trans_handle *trans,
		struct btrfs_root *fs_root,

fs/btrfs/dir-item.c

+144 −60

Original line number	Diff line number	Diff line
		@@ -4,24 +4,31 @@
		#include "hash.h"
		#include "transaction.h"

		int insert_with_overflow(struct btrfs_trans_handle *trans, struct btrfs_root
		root, struct btrfs_path path, struct btrfs_key
		*cpu_key, u32 data_size)
		struct btrfs_dir_item insert_with_overflow(struct btrfs_trans_handle trans,
		struct btrfs_root *root,
		struct btrfs_path *path,
		struct btrfs_key *cpu_key,
		u32 data_size)
		{
		int overflow;
		int ret;
		char *ptr;
		struct btrfs_item *item;
		struct btrfs_leaf *leaf;

		ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
		overflow = btrfs_key_overflow(cpu_key);

		while(ret == -EEXIST && overflow < BTRFS_KEY_OVERFLOW_MAX) {
		overflow++;
		btrfs_set_key_overflow(cpu_key, overflow);
		btrfs_release_path(root, path);
		ret = btrfs_insert_empty_item(trans, root, path, cpu_key,
		data_size);
		if (ret == -EEXIST) {
		ret = btrfs_extend_item(trans, root, path, data_size);
		WARN_ON(ret > 0);
		if (ret)
		return ERR_PTR(ret);
		}
		return ret;
		WARN_ON(ret > 0);
		leaf = btrfs_buffer_leaf(path->nodes[0]);
		item = leaf->items + path->slots[0];
		ptr = btrfs_item_ptr(leaf, path->slots[0], char);
		BUG_ON(data_size > btrfs_item_size(item));
		ptr += btrfs_item_size(item) - data_size;
		return (struct btrfs_dir_item *)ptr;
		}

		int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
		@@ -43,13 +50,12 @@ int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
		path = btrfs_alloc_path();
		btrfs_init_path(path);
		data_size = sizeof(*dir_item) + name_len;
		ret = insert_with_overflow(trans, root, path, &key, data_size);
		if (ret)
		dir_item = insert_with_overflow(trans, root, path, &key, data_size);
		if (IS_ERR(dir_item)) {
		ret = PTR_ERR(dir_item);
		goto out;
		}

		dir_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
		path->slots[0],
		struct btrfs_dir_item);
		btrfs_cpu_key_to_disk(&dir_item->location, location);
		btrfs_set_dir_type(dir_item, type);
		btrfs_set_dir_flags(dir_item, 0);
		@@ -58,15 +64,39 @@ int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root

		btrfs_memcpy(root, path->nodes[0]->b_data, name_ptr, name, name_len);
		btrfs_mark_buffer_dirty(path->nodes[0]);
		out:

		/* FIXME, use some real flag for selecting the extra index */
		if (root == root->fs_info->tree_root) {
		ret = 0;
		goto out;
		}

		btrfs_release_path(root, path);

		btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
		key.offset = location->objectid;
		dir_item = insert_with_overflow(trans, root, path, &key, data_size);
		if (IS_ERR(dir_item)) {
		ret = PTR_ERR(dir_item);
		goto out;
		}
		btrfs_cpu_key_to_disk(&dir_item->location, location);
		btrfs_set_dir_type(dir_item, type);
		btrfs_set_dir_flags(dir_item, 0);
		btrfs_set_dir_name_len(dir_item, name_len);
		name_ptr = (char *)(dir_item + 1);
		btrfs_memcpy(root, path->nodes[0]->b_data, name_ptr, name, name_len);
		btrfs_mark_buffer_dirty(path->nodes[0]);
		out:
		btrfs_free_path(path);
		return ret;
		}

		int btrfs_lookup_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
		root, struct btrfs_path path, u64 dir,
		const char *name, int name_len, int mod)
		struct btrfs_dir_item btrfs_lookup_dir_item(struct btrfs_trans_handle trans,
		struct btrfs_root *root,
		struct btrfs_path *path, u64 dir,
		const char *name, int name_len,
		int mod)
		{
		int ret;
		struct btrfs_key key;
		@@ -74,21 +104,18 @@ int btrfs_lookup_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
		int cow = mod != 0;
		struct btrfs_disk_key *found_key;
		struct btrfs_leaf *leaf;
		u32 overflow;

		key.objectid = dir;
		key.flags = 0;
		btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
		// btrfs_set_key_overflow(&key, BTRFS_KEY_OVERFLOW_MAX - 1);
		ret = btrfs_name_hash(name, name_len, &key.offset);
		BUG_ON(ret);
		while(1) {
		ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
		if (ret < 0)
		return ret;
		return ERR_PTR(ret);
		if (ret > 0) {
		if (path->slots[0] == 0)
		return 1;
		return NULL;
		path->slots[0]--;
		}
		leaf = btrfs_buffer_leaf(path->nodes[0]);
		@@ -97,34 +124,91 @@ int btrfs_lookup_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
		if (btrfs_disk_key_objectid(found_key) != dir \|\|
		btrfs_disk_key_type(found_key) != BTRFS_DIR_ITEM_KEY \|\|
		btrfs_disk_key_offset(found_key) != key.offset)
		return 1;
		return NULL;

		if (btrfs_match_dir_item_name(root, path, name, name_len))
		return 0;

		overflow = btrfs_disk_key_overflow(found_key);
		if (overflow == 0)
		return 1;
		btrfs_set_key_overflow(&key, overflow - 1);
		btrfs_release_path(root, path);
		return btrfs_match_dir_item_name(root, path, name, name_len);
		}
		return 1;

		struct btrfs_dir_item *
		btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
		struct btrfs_root *root,
		struct btrfs_path *path, u64 dir,
		u64 objectid, const char *name, int name_len,
		int mod)
		{
		int ret;
		struct btrfs_key key;
		int ins_len = mod < 0 ? -1 : 0;
		int cow = mod != 0;

		key.objectid = dir;
		key.flags = 0;
		btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
		key.offset = objectid;

		ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
		if (ret < 0)
		return ERR_PTR(ret);
		if (ret > 0)
		return ERR_PTR(-ENOENT);
		return btrfs_match_dir_item_name(root, path, name, name_len);
		}

		int btrfs_match_dir_item_name(struct btrfs_root *root,
		struct btrfs_dir_item btrfs_match_dir_item_name(struct btrfs_root root,
		struct btrfs_path *path,
		const char *name, int name_len)
		{
		struct btrfs_dir_item *dir_item;
		char *name_ptr;
		u32 total_len;
		u32 cur = 0;
		u32 this_len;
		struct btrfs_leaf *leaf;

		dir_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
		path->slots[0],
		struct btrfs_dir_item);
		if (btrfs_dir_name_len(dir_item) != name_len)
		return 0;
		leaf = btrfs_buffer_leaf(path->nodes[0]);
		dir_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dir_item);
		total_len = btrfs_item_size(leaf->items + path->slots[0]);
		while(cur < total_len) {
		this_len = sizeof(*dir_item) + btrfs_dir_name_len(dir_item);
		name_ptr = (char *)(dir_item + 1);
		if (memcmp(name_ptr, name, name_len))

		if (btrfs_dir_name_len(dir_item) == name_len &&
		memcmp(name_ptr, name, name_len) == 0)
		return dir_item;

		cur += this_len;
		dir_item = (struct btrfs_dir_item )((char )dir_item +
		this_len);
		}
		return NULL;
		}

		int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans,
		struct btrfs_root *root,
		struct btrfs_path *path,
		struct btrfs_dir_item *di)
		{

		struct btrfs_leaf *leaf;
		u32 sub_item_len;
		u32 item_len;
		int ret;

		leaf = btrfs_buffer_leaf(path->nodes[0]);
		sub_item_len = sizeof(*di) + btrfs_dir_name_len(di);
		item_len = btrfs_item_size(leaf->items + path->slots[0]);
		if (sub_item_len == btrfs_item_size(leaf->items + path->slots[0])) {
		ret = btrfs_del_item(trans, root, path);
		BUG_ON(ret);
		} else {
		char ptr = (char )di;
		char *start = btrfs_item_ptr(leaf, path->slots[0], char);
		btrfs_memmove(root, leaf, ptr, ptr + sub_item_len,
		item_len - (ptr + sub_item_len - start));
		ret = btrfs_truncate_item(trans, root, path,
		item_len - sub_item_len);
		BUG_ON(ret);
		}
		return 0;
		return 1;
		}

fs/btrfs/super.c

+43 −259

Original line number	Diff line number	Diff line
		@@ -127,32 +127,43 @@ static int btrfs_unlink_trans(struct btrfs_trans_handle *trans,
		struct btrfs_path *path;
		const char *name = dentry->d_name.name;
		int name_len = dentry->d_name.len;
		int ret;
		int ret = 0;
		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,
		di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
		name, name_len, -1);
		if (ret < 0)
		if (IS_ERR(di)) {
		ret = PTR_ERR(di);
		goto err;
		if (ret > 0) {
		}
		if (!di) {
		ret = -ENOENT;
		goto err;
		}
		di = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
		struct btrfs_dir_item);
		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);

		ret = btrfs_del_item(trans, 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);

		btrfs_release_path(root, path);
		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);
		@@ -388,15 +399,13 @@ static int btrfs_inode_by_name(struct inode dir, struct dentry dentry,
		path = btrfs_alloc_path();
		BUG_ON(!path);
		btrfs_init_path(path);
		ret = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
		di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
		namelen, 0);
		if (ret \|\| !btrfs_match_dir_item_name(root, path, name, namelen)) {
		if (!di \|\| IS_ERR(di)) {
		location->objectid = 0;
		ret = 0;
		goto out;
		}
		di = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
		struct btrfs_dir_item);
		btrfs_disk_key_to_cpu(location, &di->location);
		out:
		btrfs_release_path(root, path);
		@@ -523,7 +532,10 @@ static int btrfs_readdir(struct file filp, void dirent, filldir_t filldir)
		int advance;
		unsigned char d_type = DT_UNKNOWN;
		int over = 0;
		int key_type = BTRFS_DIR_ITEM_KEY;
		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)
		@@ -567,12 +579,20 @@ static int btrfs_readdir(struct file filp, void dirent, filldir_t filldir)
		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);
		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:
		@@ -935,75 +955,6 @@ printk("btrfs sync_fs\n");
		return 0;
		}

		#if 0
		static int btrfs_get_block_inline(struct inode *inode, sector_t iblock,
		struct buffer_head *result, int create)
		{
		struct btrfs_root *root = btrfs_sb(inode->i_sb);
		struct btrfs_path *path;
		struct btrfs_key key;
		struct btrfs_leaf *leaf;
		int num_bytes = result->b_size;
		int item_size;
		int ret;
		u64 pos;
		char *ptr;
		int copy_size;
		int err = 0;
		char *safe_ptr;
		char *data_ptr;

		path = btrfs_alloc_path();
		BUG_ON(!path);

		WARN_ON(create);
		if (create) {
		return 0;
		}
		pos = iblock << inode->i_blkbits;
		key.objectid = inode->i_ino;
		key.flags = 0;
		btrfs_set_key_type(&key, BTRFS_INLINE_DATA_KEY);
		ptr = kmap(result->b_page);
		safe_ptr = ptr;
		ptr += (pos & (PAGE_CACHE_SIZE -1));
		again:
		key.offset = pos;
		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
		if (ret) {
		if (ret < 0)
		err = ret;
		else
		err = 0;
		goto out;
		}
		leaf = btrfs_buffer_leaf(path->nodes[0]);
		item_size = btrfs_item_size(leaf->items + path->slots[0]);
		copy_size = min(num_bytes, item_size);
		data_ptr = btrfs_item_ptr(leaf, path->slots[0], char);
		WARN_ON(safe_ptr + PAGE_CACHE_SIZE < ptr + copy_size);
		memcpy(ptr, data_ptr, copy_size);
		pos += copy_size;
		num_bytes -= copy_size;
		WARN_ON(num_bytes < 0);
		ptr += copy_size;
		btrfs_release_path(root, path);
		if (num_bytes != 0) {
		if (pos >= i_size_read(inode))
		memset(ptr, 0, num_bytes);
		else
		goto again;
		}
		set_buffer_uptodate(result);
		map_bh(result, inode->i_sb, 0);
		err = 0;
		out:
		btrfs_free_path(path);
		kunmap(result->b_page);
		return err;
		}
		#endif

		static int btrfs_get_block_lock(struct inode *inode, sector_t iblock,
		struct buffer_head *result, int create)
		{
		@@ -1907,174 +1858,6 @@ static ssize_t btrfs_file_write(struct file file, const char __user buf,
		return num_written ? num_written : err;
		}

		#if 0
		static ssize_t inline_one_page(struct btrfs_root root, struct inode inode,
		struct page *page, loff_t pos,
		size_t offset, size_t write_bytes)
		{
		struct btrfs_path *path;
		struct btrfs_trans_handle *trans;
		struct btrfs_key key;
		struct btrfs_leaf *leaf;
		struct btrfs_key found_key;
		int ret;
		size_t copy_size = 0;
		char *dst = NULL;
		int err = 0;
		size_t num_written = 0;

		path = btrfs_alloc_path();
		BUG_ON(!path);
		mutex_lock(&root->fs_info->fs_mutex);
		trans = btrfs_start_transaction(root, 1);
		key.objectid = inode->i_ino;
		key.flags = 0;
		btrfs_set_key_type(&key, BTRFS_INLINE_DATA_KEY);

		again:
		key.offset = pos;
		ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
		if (ret < 0) {
		err = ret;
		goto out;
		}
		if (ret == 0) {
		leaf = btrfs_buffer_leaf(path->nodes[0]);
		btrfs_disk_key_to_cpu(&found_key,
		&leaf->items[path->slots[0]].key);
		copy_size = btrfs_item_size(leaf->items + path->slots[0]);
		dst = btrfs_item_ptr(leaf, path->slots[0], char);
		copy_size = min(write_bytes, copy_size);
		goto copyit;
		} else {
		int slot = path->slots[0];
		if (slot > 0) {
		slot--;
		}
		// FIXME find max key
		leaf = btrfs_buffer_leaf(path->nodes[0]);
		btrfs_disk_key_to_cpu(&found_key,
		&leaf->items[slot].key);
		if (found_key.objectid != inode->i_ino)
		goto insert;
		if (btrfs_key_type(&found_key) != BTRFS_INLINE_DATA_KEY)
		goto insert;
		copy_size = btrfs_item_size(leaf->items + slot);
		if (found_key.offset + copy_size <= pos)
		goto insert;
		dst = btrfs_item_ptr(leaf, path->slots[0], char);
		dst += pos - found_key.offset;
		copy_size = copy_size - (pos - found_key.offset);
		BUG_ON(copy_size < 0);
		copy_size = min(write_bytes, copy_size);
		WARN_ON(copy_size == 0);
		goto copyit;
		}
		insert:
		btrfs_release_path(root, path);
		copy_size = min(write_bytes,
		(size_t)BTRFS_LEAF_DATA_SIZE(root) -
		sizeof(struct btrfs_item) * 4);
		ret = btrfs_insert_empty_item(trans, root, path, &key, copy_size);
		BUG_ON(ret);
		dst = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
		path->slots[0], char);
		copyit:
		WARN_ON(copy_size == 0);
		WARN_ON(dst + copy_size >
		btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
		path->slots[0], char) +
		btrfs_item_size(btrfs_buffer_leaf(path->nodes[0])->items +
		path->slots[0]));
		btrfs_memcpy(root, path->nodes[0]->b_data, dst,
		page_address(page) + offset, copy_size);
		mark_buffer_dirty(path->nodes[0]);
		btrfs_release_path(root, path);
		pos += copy_size;
		offset += copy_size;
		num_written += copy_size;
		write_bytes -= copy_size;
		if (write_bytes)
		goto again;
		out:
		btrfs_free_path(path);
		ret = btrfs_end_transaction(trans, root);
		BUG_ON(ret);
		mutex_unlock(&root->fs_info->fs_mutex);
		return num_written ? num_written : err;
		}

		static ssize_t btrfs_file_inline_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;
		unsigned long page_index;

		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);
		struct page *page;

		page_index = pos >> PAGE_CACHE_SHIFT;
		page = grab_cache_page(inode->i_mapping, page_index);
		if (!PageUptodate(page)) {
		ret = mpage_readpage(page, btrfs_get_block);
		BUG_ON(ret);
		lock_page(page);
		}
		ret = btrfs_copy_from_user(pos, 1,
		write_bytes, &page, buf);
		BUG_ON(ret);
		write_bytes = inline_one_page(root, inode, page, pos,
		offset, write_bytes);
		SetPageUptodate(page);
		if (write_bytes > 0 && pos + write_bytes > inode->i_size) {
		i_size_write(inode, pos + write_bytes);
		mark_inode_dirty(inode);
		}
		page_cache_release(page);
		unlock_page(page);
		if (write_bytes < 0)
		goto out_unlock;
		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:
		*ppos = pos;
		current->backing_dev_info = NULL;
		return num_written ? num_written : err;
		}
		#endif

		static int btrfs_read_actor(read_descriptor_t desc, struct page page,
		unsigned long offset, unsigned long size)
		{
		@@ -2422,6 +2205,7 @@ static int btrfs_ioctl(struct inode inode, struct file filp, unsigned int
		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;
		@@ -2440,12 +2224,12 @@ static int btrfs_ioctl(struct inode inode, struct file filp, unsigned int
		return -ENOMEM;
		root_dirid = root->fs_info->sb->s_root->d_inode->i_ino,
		mutex_lock(&root->fs_info->fs_mutex);
		ret = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root,
		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 (ret == 0)
		if (di && !IS_ERR(di))
		return -EEXIST;

		if (root == root->fs_info->tree_root)