[linux-block.git] / fs / btrfs / props.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2014 Filipe David Borba Manana <fdmanana@gmail.com>
 */

#include <linux/hashtable.h>
#include "props.h"
#include "btrfs_inode.h"
#include "transaction.h"
#include "ctree.h"
#include "xattr.h"
#include "compression.h"

#define BTRFS_PROP_HANDLERS_HT_BITS 8
static DEFINE_HASHTABLE(prop_handlers_ht, BTRFS_PROP_HANDLERS_HT_BITS);

struct prop_handler {
	struct hlist_node node;
	const char *xattr_name;
	int (*validate)(const struct btrfs_inode *inode, const char *value,
			size_t len);
	int (*apply)(struct inode *inode, const char *value, size_t len);
	const char *(*extract)(struct inode *inode);
	bool (*ignore)(const struct btrfs_inode *inode);
	int inheritable;
};

static const struct hlist_head *find_prop_handlers_by_hash(const u64 hash)
{
	struct hlist_head *h;

	h = &prop_handlers_ht[hash_min(hash, BTRFS_PROP_HANDLERS_HT_BITS)];
	if (hlist_empty(h))
		return NULL;

	return h;
}

static const struct prop_handler *
find_prop_handler(const char *name,
		  const struct hlist_head *handlers)
{
	struct prop_handler *h;

	if (!handlers) {
		u64 hash = btrfs_name_hash(name, strlen(name));

		handlers = find_prop_handlers_by_hash(hash);
		if (!handlers)
			return NULL;
	}

	hlist_for_each_entry(h, handlers, node)
		if (!strcmp(h->xattr_name, name))
			return h;

	return NULL;
}

int btrfs_validate_prop(const struct btrfs_inode *inode, const char *name,
			const char *value, size_t value_len)
{
	const struct prop_handler *handler;

	if (strlen(name) <= XATTR_BTRFS_PREFIX_LEN)
		return -EINVAL;

	handler = find_prop_handler(name, NULL);
	if (!handler)
		return -EINVAL;

	if (value_len == 0)
		return 0;

	return handler->validate(inode, value, value_len);
}

/*
 * Check if a property should be ignored (not set) for an inode.
 *
 * @inode:     The target inode.
 * @name:      The property's name.
 *
 * The caller must be sure the given property name is valid, for example by
 * having previously called btrfs_validate_prop().
 *
 * Returns:    true if the property should be ignored for the given inode
 *             false if the property must not be ignored for the given inode
 */
bool btrfs_ignore_prop(const struct btrfs_inode *inode, const char *name)
{
	const struct prop_handler *handler;

	handler = find_prop_handler(name, NULL);
	ASSERT(handler != NULL);

	return handler->ignore(inode);
}

int btrfs_set_prop(struct btrfs_trans_handle *trans, struct inode *inode,
		   const char *name, const char *value, size_t value_len,
		   int flags)
{
	const struct prop_handler *handler;
	int ret;

	handler = find_prop_handler(name, NULL);
	if (!handler)
		return -EINVAL;

	if (value_len == 0) {
		ret = btrfs_setxattr(trans, inode, handler->xattr_name,
				     NULL, 0, flags);
		if (ret)
			return ret;

		ret = handler->apply(inode, NULL, 0);
		ASSERT(ret == 0);

		return ret;
	}

	ret = btrfs_setxattr(trans, inode, handler->xattr_name, value,
			     value_len, flags);
	if (ret)
		return ret;
	ret = handler->apply(inode, value, value_len);
	if (ret) {
		btrfs_setxattr(trans, inode, handler->xattr_name, NULL,
			       0, flags);
		return ret;
	}

	set_bit(BTRFS_INODE_HAS_PROPS, &BTRFS_I(inode)->runtime_flags);

	return 0;
}

static int iterate_object_props(struct btrfs_root *root,
				struct btrfs_path *path,
				u64 objectid,
				void (*iterator)(void *,
						 const struct prop_handler *,
						 const char *,
						 size_t),
				void *ctx)
{
	int ret;
	char *name_buf = NULL;
	char *value_buf = NULL;
	int name_buf_len = 0;
	int value_buf_len = 0;

	while (1) {
		struct btrfs_key key;
		struct btrfs_dir_item *di;
		struct extent_buffer *leaf;
		u32 total_len, cur, this_len;
		int slot;
		const struct hlist_head *handlers;

		slot = path->slots[0];
		leaf = path->nodes[0];

		if (slot >= btrfs_header_nritems(leaf)) {
			ret = btrfs_next_leaf(root, path);
			if (ret < 0)
				goto out;
			else if (ret > 0)
				break;
			continue;
		}

		btrfs_item_key_to_cpu(leaf, &key, slot);
		if (key.objectid != objectid)
			break;
		if (key.type != BTRFS_XATTR_ITEM_KEY)
			break;

		handlers = find_prop_handlers_by_hash(key.offset);
		if (!handlers)
			goto next_slot;

		di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
		cur = 0;
		total_len = btrfs_item_size(leaf, slot);

		while (cur < total_len) {
			u32 name_len = btrfs_dir_name_len(leaf, di);
			u32 data_len = btrfs_dir_data_len(leaf, di);
			unsigned long name_ptr, data_ptr;
			const struct prop_handler *handler;

			this_len = sizeof(*di) + name_len + data_len;
			name_ptr = (unsigned long)(di + 1);
			data_ptr = name_ptr + name_len;

			if (name_len <= XATTR_BTRFS_PREFIX_LEN ||
			    memcmp_extent_buffer(leaf, XATTR_BTRFS_PREFIX,
						 name_ptr,
						 XATTR_BTRFS_PREFIX_LEN))
				goto next_dir_item;

			if (name_len >= name_buf_len) {
				kfree(name_buf);
				name_buf_len = name_len + 1;
				name_buf = kmalloc(name_buf_len, GFP_NOFS);
				if (!name_buf) {
					ret = -ENOMEM;
					goto out;
				}
			}
			read_extent_buffer(leaf, name_buf, name_ptr, name_len);
			name_buf[name_len] = '\0';

			handler = find_prop_handler(name_buf, handlers);
			if (!handler)
				goto next_dir_item;

			if (data_len > value_buf_len) {
				kfree(value_buf);
				value_buf_len = data_len;
				value_buf = kmalloc(data_len, GFP_NOFS);
				if (!value_buf) {
					ret = -ENOMEM;
					goto out;
				}
			}
			read_extent_buffer(leaf, value_buf, data_ptr, data_len);

			iterator(ctx, handler, value_buf, data_len);
next_dir_item:
			cur += this_len;
			di = (struct btrfs_dir_item *)((char *) di + this_len);
		}

next_slot:
		path->slots[0]++;
	}

	ret = 0;
out:
	btrfs_release_path(path);
	kfree(name_buf);
	kfree(value_buf);

	return ret;
}

static void inode_prop_iterator(void *ctx,
				const struct prop_handler *handler,
				const char *value,
				size_t len)
{
	struct inode *inode = ctx;
	struct btrfs_root *root = BTRFS_I(inode)->root;
	int ret;

	ret = handler->apply(inode, value, len);
	if (unlikely(ret))
		btrfs_warn(root->fs_info,
			   "error applying prop %s to ino %llu (root %llu): %d",
			   handler->xattr_name, btrfs_ino(BTRFS_I(inode)),
			   root->root_key.objectid, ret);
	else
		set_bit(BTRFS_INODE_HAS_PROPS, &BTRFS_I(inode)->runtime_flags);
}

int btrfs_load_inode_props(struct inode *inode, struct btrfs_path *path)
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	u64 ino = btrfs_ino(BTRFS_I(inode));

	return iterate_object_props(root, path, ino, inode_prop_iterator, inode);
}

static int prop_compression_validate(const struct btrfs_inode *inode,
				     const char *value, size_t len)
{
	if (!btrfs_inode_can_compress(inode))
		return -EINVAL;

	if (!value)
		return 0;

	if (btrfs_compress_is_valid_type(value, len))
		return 0;

	if ((len == 2 && strncmp("no", value, 2) == 0) ||
	    (len == 4 && strncmp("none", value, 4) == 0))
		return 0;

	return -EINVAL;
}

static int prop_compression_apply(struct inode *inode, const char *value,
				  size_t len)
{
	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
	int type;

	/* Reset to defaults */
	if (len == 0) {
		BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
		BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
		BTRFS_I(inode)->prop_compress = BTRFS_COMPRESS_NONE;
		return 0;
	}

	/* Set NOCOMPRESS flag */
	if ((len == 2 && strncmp("no", value, 2) == 0) ||
	    (len == 4 && strncmp("none", value, 4) == 0)) {
		BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
		BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
		BTRFS_I(inode)->prop_compress = BTRFS_COMPRESS_NONE;

		return 0;
	}

	if (!strncmp("lzo", value, 3)) {
		type = BTRFS_COMPRESS_LZO;
		btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
	} else if (!strncmp("zlib", value, 4)) {
		type = BTRFS_COMPRESS_ZLIB;
	} else if (!strncmp("zstd", value, 4)) {
		type = BTRFS_COMPRESS_ZSTD;
		btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD);
	} else {
		return -EINVAL;
	}

	BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
	BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
	BTRFS_I(inode)->prop_compress = type;

	return 0;
}

static bool prop_compression_ignore(const struct btrfs_inode *inode)
{
	/*
	 * Compression only has effect for regular files, and for directories
	 * we set it just to propagate it to new files created inside them.
	 * Everything else (symlinks, devices, sockets, fifos) is pointless as
	 * it will do nothing, so don't waste metadata space on a compression
	 * xattr for anything that is neither a file nor a directory.
	 */
	if (!S_ISREG(inode->vfs_inode.i_mode) &&
	    !S_ISDIR(inode->vfs_inode.i_mode))
		return true;

	return false;
}

static const char *prop_compression_extract(struct inode *inode)
{
	switch (BTRFS_I(inode)->prop_compress) {
	case BTRFS_COMPRESS_ZLIB:
	case BTRFS_COMPRESS_LZO:
	case BTRFS_COMPRESS_ZSTD:
		return btrfs_compress_type2str(BTRFS_I(inode)->prop_compress);
	default:
		break;
	}

	return NULL;
}

static struct prop_handler prop_handlers[] = {
	{
		.xattr_name = XATTR_BTRFS_PREFIX "compression",
		.validate = prop_compression_validate,
		.apply = prop_compression_apply,
		.extract = prop_compression_extract,
		.ignore = prop_compression_ignore,
		.inheritable = 1
	},
};

int btrfs_inode_inherit_props(struct btrfs_trans_handle *trans,
			      struct inode *inode, struct inode *parent)
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_fs_info *fs_info = root->fs_info;
	int ret;
	int i;
	bool need_reserve = false;

	if (!test_bit(BTRFS_INODE_HAS_PROPS,
		      &BTRFS_I(parent)->runtime_flags))
		return 0;

	for (i = 0; i < ARRAY_SIZE(prop_handlers); i++) {
		const struct prop_handler *h = &prop_handlers[i];
		const char *value;
		u64 num_bytes = 0;

		if (!h->inheritable)
			continue;

		if (h->ignore(BTRFS_I(inode)))
			continue;

		value = h->extract(parent);
		if (!value)
			continue;

		/*
		 * This is not strictly necessary as the property should be
		 * valid, but in case it isn't, don't propagate it further.
		 */
		ret = h->validate(BTRFS_I(inode), value, strlen(value));
		if (ret)
			continue;

		/*
		 * Currently callers should be reserving 1 item for properties,
		 * since we only have 1 property that we currently support.  If
		 * we add more in the future we need to try and reserve more
		 * space for them.  But we should also revisit how we do space
		 * reservations if we do add more properties in the future.
		 */
		if (need_reserve) {
			num_bytes = btrfs_calc_insert_metadata_size(fs_info, 1);
			ret = btrfs_block_rsv_add(fs_info, trans->block_rsv,
						  num_bytes,
						  BTRFS_RESERVE_NO_FLUSH);
			if (ret)
				return ret;
		}

		ret = btrfs_setxattr(trans, inode, h->xattr_name, value,
				     strlen(value), 0);
		if (!ret) {
			ret = h->apply(inode, value, strlen(value));
			if (ret)
				btrfs_setxattr(trans, inode, h->xattr_name,
					       NULL, 0, 0);
			else
				set_bit(BTRFS_INODE_HAS_PROPS,
					&BTRFS_I(inode)->runtime_flags);
		}

		if (need_reserve) {
			btrfs_block_rsv_release(fs_info, trans->block_rsv,
					num_bytes, NULL);
			if (ret)
				return ret;
		}
		need_reserve = true;
	}

	return 0;
}

void __init btrfs_props_init(void)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(prop_handlers); i++) {
		struct prop_handler *p = &prop_handlers[i];
		u64 h = btrfs_name_hash(p->xattr_name, strlen(p->xattr_name));

		hash_add(prop_handlers_ht, &p->node, h);
	}
}
Commit	Line	Data
c1d7c514	1	// SPDX-License-Identifier: GPL-2.0
63541927 FDBM	2	/*
63541927 FDBM	3	* Copyright (C) 2014 Filipe David Borba Manana <fdmanana@gmail.com>
63541927 FDBM	4	*/
	5
	6	#include <linux/hashtable.h>
	7	#include "props.h"
	8	#include "btrfs_inode.h"
63541927	9	#include "transaction.h"
9678c543	10	#include "ctree.h"
63541927	11	#include "xattr.h"
ebb8765b	12	#include "compression.h"
63541927 FDBM	13
	14	#define BTRFS_PROP_HANDLERS_HT_BITS 8
	15	static DEFINE_HASHTABLE(prop_handlers_ht, BTRFS_PROP_HANDLERS_HT_BITS);
	16
	17	struct prop_handler {
	18	struct hlist_node node;
	19	const char *xattr_name;
0e852ab8 CCC	20	int (validate)(const struct btrfs_inode inode, const char *value,
0e852ab8 CCC	21	size_t len);
63541927 FDBM	22	int (apply)(struct inode inode, const char *value, size_t len);
63541927 FDBM	23	const char (extract)(struct inode *inode);
4b73c55f	24	bool (ignore)(const struct btrfs_inode inode);
63541927 FDBM	25	int inheritable;
	26	};
	27
63541927 FDBM	28	static const struct hlist_head *find_prop_handlers_by_hash(const u64 hash)
	29	{
	30	struct hlist_head *h;
	31
	32	h = &prop_handlers_ht[hash_min(hash, BTRFS_PROP_HANDLERS_HT_BITS)];
	33	if (hlist_empty(h))
	34	return NULL;
	35
	36	return h;
	37	}
	38
	39	static const struct prop_handler *
	40	find_prop_handler(const char *name,
	41	const struct hlist_head *handlers)
	42	{
	43	struct prop_handler *h;
	44
	45	if (!handlers) {
	46	u64 hash = btrfs_name_hash(name, strlen(name));
	47
	48	handlers = find_prop_handlers_by_hash(hash);
	49	if (!handlers)
	50	return NULL;
	51	}
	52
	53	hlist_for_each_entry(h, handlers, node)
	54	if (!strcmp(h->xattr_name, name))
	55	return h;
	56
	57	return NULL;
	58	}
	59
0e852ab8 CCC	60	int btrfs_validate_prop(const struct btrfs_inode inode, const char name,
0e852ab8 CCC	61	const char *value, size_t value_len)
f22125e5 AJ	62	{
	63	const struct prop_handler *handler;
	64
	65	if (strlen(name) <= XATTR_BTRFS_PREFIX_LEN)
	66	return -EINVAL;
	67
	68	handler = find_prop_handler(name, NULL);
	69	if (!handler)
	70	return -EINVAL;
	71
	72	if (value_len == 0)
	73	return 0;
	74
0e852ab8	75	return handler->validate(inode, value, value_len);
f22125e5 AJ	76	}
f22125e5 AJ	77
4b73c55f FM	78	/*
	79	* Check if a property should be ignored (not set) for an inode.
	80	*
	81	* @inode: The target inode.
	82	* @name: The property's name.
	83	*
	84	* The caller must be sure the given property name is valid, for example by
	85	* having previously called btrfs_validate_prop().
	86	*
	87	* Returns: true if the property should be ignored for the given inode
	88	* false if the property must not be ignored for the given inode
	89	*/
	90	bool btrfs_ignore_prop(const struct btrfs_inode inode, const char name)
	91	{
	92	const struct prop_handler *handler;
	93
	94	handler = find_prop_handler(name, NULL);
	95	ASSERT(handler != NULL);
	96
	97	return handler->ignore(inode);
	98	}
	99
cd31af15 AJ	100	int btrfs_set_prop(struct btrfs_trans_handle trans, struct inode inode,
	101	const char name, const char value, size_t value_len,
	102	int flags)
63541927 FDBM	103	{
	104	const struct prop_handler *handler;
	105	int ret;
	106
63541927 FDBM	107	handler = find_prop_handler(name, NULL);
	108	if (!handler)
	109	return -EINVAL;
	110
	111	if (value_len == 0) {
da9b6ec8 AJ	112	ret = btrfs_setxattr(trans, inode, handler->xattr_name,
da9b6ec8 AJ	113	NULL, 0, flags);
63541927 FDBM	114	if (ret)
	115	return ret;
	116
	117	ret = handler->apply(inode, NULL, 0);
	118	ASSERT(ret == 0);
	119
	120	return ret;
	121	}
	122
da9b6ec8 AJ	123	ret = btrfs_setxattr(trans, inode, handler->xattr_name, value,
da9b6ec8 AJ	124	value_len, flags);
63541927 FDBM	125	if (ret)
	126	return ret;
	127	ret = handler->apply(inode, value, value_len);
	128	if (ret) {
da9b6ec8 AJ	129	btrfs_setxattr(trans, inode, handler->xattr_name, NULL,
da9b6ec8 AJ	130	0, flags);
63541927 FDBM	131	return ret;
	132	}
	133
	134	set_bit(BTRFS_INODE_HAS_PROPS, &BTRFS_I(inode)->runtime_flags);
	135
	136	return 0;
	137	}
	138
63541927 FDBM	139	static int iterate_object_props(struct btrfs_root *root,
	140	struct btrfs_path *path,
	141	u64 objectid,
	142	void (iterator)(void ,
	143	const struct prop_handler *,
	144	const char *,
	145	size_t),
	146	void *ctx)
	147	{
	148	int ret;
	149	char *name_buf = NULL;
	150	char *value_buf = NULL;
	151	int name_buf_len = 0;
	152	int value_buf_len = 0;
	153
	154	while (1) {
	155	struct btrfs_key key;
	156	struct btrfs_dir_item *di;
	157	struct extent_buffer *leaf;
	158	u32 total_len, cur, this_len;
	159	int slot;
	160	const struct hlist_head *handlers;
	161
	162	slot = path->slots[0];
	163	leaf = path->nodes[0];
	164
	165	if (slot >= btrfs_header_nritems(leaf)) {
	166	ret = btrfs_next_leaf(root, path);
	167	if (ret < 0)
	168	goto out;
	169	else if (ret > 0)
	170	break;
	171	continue;
	172	}
	173
	174	btrfs_item_key_to_cpu(leaf, &key, slot);
	175	if (key.objectid != objectid)
	176	break;
	177	if (key.type != BTRFS_XATTR_ITEM_KEY)
	178	break;
	179
	180	handlers = find_prop_handlers_by_hash(key.offset);
	181	if (!handlers)
	182	goto next_slot;
	183
	184	di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
	185	cur = 0;
3212fa14	186	total_len = btrfs_item_size(leaf, slot);
63541927 FDBM	187
	188	while (cur < total_len) {
	189	u32 name_len = btrfs_dir_name_len(leaf, di);
	190	u32 data_len = btrfs_dir_data_len(leaf, di);
	191	unsigned long name_ptr, data_ptr;
	192	const struct prop_handler *handler;
	193
	194	this_len = sizeof(*di) + name_len + data_len;
	195	name_ptr = (unsigned long)(di + 1);
	196	data_ptr = name_ptr + name_len;
	197
	198	if (name_len <= XATTR_BTRFS_PREFIX_LEN \|\|
	199	memcmp_extent_buffer(leaf, XATTR_BTRFS_PREFIX,
	200	name_ptr,
	201	XATTR_BTRFS_PREFIX_LEN))
	202	goto next_dir_item;
	203
	204	if (name_len >= name_buf_len) {
	205	kfree(name_buf);
	206	name_buf_len = name_len + 1;
	207	name_buf = kmalloc(name_buf_len, GFP_NOFS);
	208	if (!name_buf) {
	209	ret = -ENOMEM;
	210	goto out;
	211	}
	212	}
	213	read_extent_buffer(leaf, name_buf, name_ptr, name_len);
	214	name_buf[name_len] = '\0';
	215
	216	handler = find_prop_handler(name_buf, handlers);
	217	if (!handler)
	218	goto next_dir_item;
	219
	220	if (data_len > value_buf_len) {
	221	kfree(value_buf);
	222	value_buf_len = data_len;
	223	value_buf = kmalloc(data_len, GFP_NOFS);
	224	if (!value_buf) {
	225	ret = -ENOMEM;
	226	goto out;
	227	}
	228	}
	229	read_extent_buffer(leaf, value_buf, data_ptr, data_len);
	230
	231	iterator(ctx, handler, value_buf, data_len);
	232	next_dir_item:
	233	cur += this_len;
	234	di = (struct btrfs_dir_item )((char ) di + this_len);
	235	}
	236
	237	next_slot:
	238	path->slots[0]++;
	239	}
	240
	241	ret = 0;
	242	out:
	243	btrfs_release_path(path);
	244	kfree(name_buf);
	245	kfree(value_buf);
	246
	247	return ret;
	248	}
	249
	250	static void inode_prop_iterator(void *ctx,
251	const struct prop_handler *handler,
252	const char *value,
253	size_t len)
254	{
255	struct inode *inode = ctx;
256	struct btrfs_root *root = BTRFS_I(inode)->root;
257	int ret;
258
259	ret = handler->apply(inode, value, len);
260	if (unlikely(ret))
261	btrfs_warn(root->fs_info,
262	"error applying prop %s to ino %llu (root %llu): %d",
4a0cc7ca	263	handler->xattr_name, btrfs_ino(BTRFS_I(inode)),
63541927 FDBM	264	root->root_key.objectid, ret);
	265	else
	266	set_bit(BTRFS_INODE_HAS_PROPS, &BTRFS_I(inode)->runtime_flags);
	267	}
	268
	269	int btrfs_load_inode_props(struct inode inode, struct btrfs_path path)
	270	{
	271	struct btrfs_root *root = BTRFS_I(inode)->root;
4a0cc7ca	272	u64 ino = btrfs_ino(BTRFS_I(inode));
63541927	273
bd64f622	274	return iterate_object_props(root, path, ino, inode_prop_iterator, inode);
63541927 FDBM	275	}
63541927 FDBM	276
0e852ab8 CCC	277	static int prop_compression_validate(const struct btrfs_inode *inode,
0e852ab8 CCC	278	const char *value, size_t len)
3dcf96c7	279	{
0e852ab8 CCC	280	if (!btrfs_inode_can_compress(inode))
	281	return -EINVAL;
	282
3dcf96c7 AJ	283	if (!value)
	284	return 0;
	285
aa53e3bf	286	if (btrfs_compress_is_valid_type(value, len))
3dcf96c7 AJ	287	return 0;
3dcf96c7 AJ	288
5548c8c6 DS	289	if ((len == 2 && strncmp("no", value, 2) == 0) \|\|
	290	(len == 4 && strncmp("none", value, 4) == 0))
	291	return 0;
	292
3dcf96c7 AJ	293	return -EINVAL;
	294	}
	295
	296	static int prop_compression_apply(struct inode inode, const char value,
	297	size_t len)
	298	{
	299	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
	300	int type;
	301
5548c8c6	302	/* Reset to defaults */
3dcf96c7	303	if (len == 0) {
5548c8c6 DS	304	BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
	305	BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
	306	BTRFS_I(inode)->prop_compress = BTRFS_COMPRESS_NONE;
	307	return 0;
	308	}
	309
	310	/* Set NOCOMPRESS flag */
	311	if ((len == 2 && strncmp("no", value, 2) == 0) \|\|
	312	(len == 4 && strncmp("none", value, 4) == 0)) {
3dcf96c7 AJ	313	BTRFS_I(inode)->flags \|= BTRFS_INODE_NOCOMPRESS;
	314	BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
	315	BTRFS_I(inode)->prop_compress = BTRFS_COMPRESS_NONE;
	316
	317	return 0;
	318	}
	319
	320	if (!strncmp("lzo", value, 3)) {
	321	type = BTRFS_COMPRESS_LZO;
	322	btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
	323	} else if (!strncmp("zlib", value, 4)) {
	324	type = BTRFS_COMPRESS_ZLIB;
	325	} else if (!strncmp("zstd", value, 4)) {
	326	type = BTRFS_COMPRESS_ZSTD;
	327	btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD);
	328	} else {
	329	return -EINVAL;
	330	}
	331
	332	BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
	333	BTRFS_I(inode)->flags \|= BTRFS_INODE_COMPRESS;
	334	BTRFS_I(inode)->prop_compress = type;
	335
	336	return 0;
	337	}
	338
4b73c55f FM	339	static bool prop_compression_ignore(const struct btrfs_inode *inode)
	340	{
	341	/*
	342	* Compression only has effect for regular files, and for directories
	343	* we set it just to propagate it to new files created inside them.
	344	* Everything else (symlinks, devices, sockets, fifos) is pointless as
	345	* it will do nothing, so don't waste metadata space on a compression
	346	* xattr for anything that is neither a file nor a directory.
	347	*/
	348	if (!S_ISREG(inode->vfs_inode.i_mode) &&
	349	!S_ISDIR(inode->vfs_inode.i_mode))
	350	return true;
	351
	352	return false;
	353	}
	354
3dcf96c7 AJ	355	static const char prop_compression_extract(struct inode inode)
	356	{
	357	switch (BTRFS_I(inode)->prop_compress) {
	358	case BTRFS_COMPRESS_ZLIB:
	359	case BTRFS_COMPRESS_LZO:
	360	case BTRFS_COMPRESS_ZSTD:
	361	return btrfs_compress_type2str(BTRFS_I(inode)->prop_compress);
	362	default:
	363	break;
	364	}
	365
	366	return NULL;
	367	}
	368
	369	static struct prop_handler prop_handlers[] = {
	370	{
	371	.xattr_name = XATTR_BTRFS_PREFIX "compression",
	372	.validate = prop_compression_validate,
	373	.apply = prop_compression_apply,
	374	.extract = prop_compression_extract,
4b73c55f	375	.ignore = prop_compression_ignore,
3dcf96c7 AJ	376	.inheritable = 1
	377	},
	378	};
	379
caae78e0 OS	380	int btrfs_inode_inherit_props(struct btrfs_trans_handle *trans,
caae78e0 OS	381	struct inode inode, struct inode parent)
63541927	382	{
63541927	383	struct btrfs_root *root = BTRFS_I(inode)->root;
2ff7e61e	384	struct btrfs_fs_info *fs_info = root->fs_info;
63541927	385	int ret;
619ed392	386	int i;
d7400ee1	387	bool need_reserve = false;
63541927 FDBM	388
	389	if (!test_bit(BTRFS_INODE_HAS_PROPS,
	390	&BTRFS_I(parent)->runtime_flags))
	391	return 0;
	392
619ed392 BL	393	for (i = 0; i < ARRAY_SIZE(prop_handlers); i++) {
619ed392 BL	394	const struct prop_handler *h = &prop_handlers[i];
63541927	395	const char *value;
6c64460c	396	u64 num_bytes = 0;
63541927 FDBM	397
	398	if (!h->inheritable)
	399	continue;
	400
4b73c55f FM	401	if (h->ignore(BTRFS_I(inode)))
	402	continue;
	403
63541927 FDBM	404	value = h->extract(parent);
	405	if (!value)
	406	continue;
	407
8b4d1efc AJ	408	/*
8b4d1efc AJ	409	* This is not strictly necessary as the property should be
1a9fd417	410	* valid, but in case it isn't, don't propagate it further.
8b4d1efc	411	*/
0e852ab8	412	ret = h->validate(BTRFS_I(inode), value, strlen(value));
8b4d1efc AJ	413	if (ret)
	414	continue;
	415
d7400ee1 JB	416	/*
	417	* Currently callers should be reserving 1 item for properties,
	418	* since we only have 1 property that we currently support. If
	419	* we add more in the future we need to try and reserve more
	420	* space for them. But we should also revisit how we do space
	421	* reservations if we do add more properties in the future.
	422	*/
	423	if (need_reserve) {
2bd36e7b	424	num_bytes = btrfs_calc_insert_metadata_size(fs_info, 1);
9270501c JB	425	ret = btrfs_block_rsv_add(fs_info, trans->block_rsv,
	426	num_bytes,
	427	BTRFS_RESERVE_NO_FLUSH);
d7400ee1 JB	428	if (ret)
	429	return ret;
	430	}
8b4d1efc	431
04e6863b AJ	432	ret = btrfs_setxattr(trans, inode, h->xattr_name, value,
04e6863b AJ	433	strlen(value), 0);
8b4d1efc AJ	434	if (!ret) {
	435	ret = h->apply(inode, value, strlen(value));
	436	if (ret)
04e6863b AJ	437	btrfs_setxattr(trans, inode, h->xattr_name,
04e6863b AJ	438	NULL, 0, 0);
8b4d1efc AJ	439	else
	440	set_bit(BTRFS_INODE_HAS_PROPS,
	441	&BTRFS_I(inode)->runtime_flags);
	442	}
	443
d7400ee1 JB	444	if (need_reserve) {
d7400ee1 JB	445	btrfs_block_rsv_release(fs_info, trans->block_rsv,
63f018be	446	num_bytes, NULL);
d7400ee1 JB	447	if (ret)
	448	return ret;
	449	}
	450	need_reserve = true;
63541927	451	}
8b4d1efc AJ	452
8b4d1efc AJ	453	return 0;
63541927 FDBM	454	}
63541927 FDBM	455
3dcf96c7	456	void __init btrfs_props_init(void)
63541927	457	{
3dcf96c7	458	int i;
63541927	459
3dcf96c7 AJ	460	for (i = 0; i < ARRAY_SIZE(prop_handlers); i++) {
	461	struct prop_handler *p = &prop_handlers[i];
	462	u64 h = btrfs_name_hash(p->xattr_name, strlen(p->xattr_name));
63541927	463
3dcf96c7	464	hash_add(prop_handlers_ht, &p->node, h);
63541927	465	}
63541927	466	}
e8c9f186	467