[linux-block.git] / fs / erofs / xattr.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2017-2018 HUAWEI, Inc.
 *             https://www.huawei.com/
 * Copyright (C) 2021-2022, Alibaba Cloud
 */
#include <linux/security.h>
#include "xattr.h"

struct xattr_iter {
	struct super_block *sb;
	struct erofs_buf buf;
	void *kaddr;

	erofs_blk_t blkaddr;
	unsigned int ofs;
};

static int init_inode_xattrs(struct inode *inode)
{
	struct erofs_inode *const vi = EROFS_I(inode);
	struct xattr_iter it;
	unsigned int i;
	struct erofs_xattr_ibody_header *ih;
	struct super_block *sb;
	struct erofs_sb_info *sbi;
	int ret = 0;

	/* the most case is that xattrs of this inode are initialized. */
	if (test_bit(EROFS_I_EA_INITED_BIT, &vi->flags)) {
		/*
		 * paired with smp_mb() at the end of the function to ensure
		 * fields will only be observed after the bit is set.
		 */
		smp_mb();
		return 0;
	}

	if (wait_on_bit_lock(&vi->flags, EROFS_I_BL_XATTR_BIT, TASK_KILLABLE))
		return -ERESTARTSYS;

	/* someone has initialized xattrs for us? */
	if (test_bit(EROFS_I_EA_INITED_BIT, &vi->flags))
		goto out_unlock;

	/*
	 * bypass all xattr operations if ->xattr_isize is not greater than
	 * sizeof(struct erofs_xattr_ibody_header), in detail:
	 * 1) it is not enough to contain erofs_xattr_ibody_header then
	 *    ->xattr_isize should be 0 (it means no xattr);
	 * 2) it is just to contain erofs_xattr_ibody_header, which is on-disk
	 *    undefined right now (maybe use later with some new sb feature).
	 */
	if (vi->xattr_isize == sizeof(struct erofs_xattr_ibody_header)) {
		erofs_err(inode->i_sb,
			  "xattr_isize %d of nid %llu is not supported yet",
			  vi->xattr_isize, vi->nid);
		ret = -EOPNOTSUPP;
		goto out_unlock;
	} else if (vi->xattr_isize < sizeof(struct erofs_xattr_ibody_header)) {
		if (vi->xattr_isize) {
			erofs_err(inode->i_sb,
				  "bogus xattr ibody @ nid %llu", vi->nid);
			DBG_BUGON(1);
			ret = -EFSCORRUPTED;
			goto out_unlock;	/* xattr ondisk layout error */
		}
		ret = -ENOATTR;
		goto out_unlock;
	}

	sb = inode->i_sb;
	sbi = EROFS_SB(sb);
	it.buf = __EROFS_BUF_INITIALIZER;
	it.blkaddr = erofs_blknr(iloc(sbi, vi->nid) + vi->inode_isize);
	it.ofs = erofs_blkoff(iloc(sbi, vi->nid) + vi->inode_isize);

	/* read in shared xattr array (non-atomic, see kmalloc below) */
	it.kaddr = erofs_read_metabuf(&it.buf, sb, it.blkaddr, EROFS_KMAP);
	if (IS_ERR(it.kaddr)) {
		ret = PTR_ERR(it.kaddr);
		goto out_unlock;
	}

	ih = (struct erofs_xattr_ibody_header *)(it.kaddr + it.ofs);
	vi->xattr_shared_count = ih->h_shared_count;
	vi->xattr_shared_xattrs = kmalloc_array(vi->xattr_shared_count,
						sizeof(uint), GFP_KERNEL);
	if (!vi->xattr_shared_xattrs) {
		erofs_put_metabuf(&it.buf);
		ret = -ENOMEM;
		goto out_unlock;
	}

	/* let's skip ibody header */
	it.ofs += sizeof(struct erofs_xattr_ibody_header);

	for (i = 0; i < vi->xattr_shared_count; ++i) {
		if (it.ofs >= EROFS_BLKSIZ) {
			/* cannot be unaligned */
			DBG_BUGON(it.ofs != EROFS_BLKSIZ);

			it.kaddr = erofs_read_metabuf(&it.buf, sb, ++it.blkaddr,
						      EROFS_KMAP);
			if (IS_ERR(it.kaddr)) {
				kfree(vi->xattr_shared_xattrs);
				vi->xattr_shared_xattrs = NULL;
				ret = PTR_ERR(it.kaddr);
				goto out_unlock;
			}
			it.ofs = 0;
		}
		vi->xattr_shared_xattrs[i] =
			le32_to_cpu(*(__le32 *)(it.kaddr + it.ofs));
		it.ofs += sizeof(__le32);
	}
	erofs_put_metabuf(&it.buf);

	/* paired with smp_mb() at the beginning of the function. */
	smp_mb();
	set_bit(EROFS_I_EA_INITED_BIT, &vi->flags);

out_unlock:
	clear_and_wake_up_bit(EROFS_I_BL_XATTR_BIT, &vi->flags);
	return ret;
}

/*
 * the general idea for these return values is
 * if    0 is returned, go on processing the current xattr;
 *       1 (> 0) is returned, skip this round to process the next xattr;
 *    -err (< 0) is returned, an error (maybe ENOXATTR) occurred
 *                            and need to be handled
 */
struct xattr_iter_handlers {
	int (*entry)(struct xattr_iter *_it, struct erofs_xattr_entry *entry);
	int (*name)(struct xattr_iter *_it, unsigned int processed, char *buf,
		    unsigned int len);
	int (*alloc_buffer)(struct xattr_iter *_it, unsigned int value_sz);
	void (*value)(struct xattr_iter *_it, unsigned int processed, char *buf,
		      unsigned int len);
};

static inline int xattr_iter_fixup(struct xattr_iter *it)
{
	if (it->ofs < EROFS_BLKSIZ)
		return 0;

	it->blkaddr += erofs_blknr(it->ofs);
	it->kaddr = erofs_read_metabuf(&it->buf, it->sb, it->blkaddr,
				       EROFS_KMAP_ATOMIC);
	if (IS_ERR(it->kaddr))
		return PTR_ERR(it->kaddr);
	it->ofs = erofs_blkoff(it->ofs);
	return 0;
}

static int inline_xattr_iter_begin(struct xattr_iter *it,
				   struct inode *inode)
{
	struct erofs_inode *const vi = EROFS_I(inode);
	struct erofs_sb_info *const sbi = EROFS_SB(inode->i_sb);
	unsigned int xattr_header_sz, inline_xattr_ofs;

	xattr_header_sz = inlinexattr_header_size(inode);
	if (xattr_header_sz >= vi->xattr_isize) {
		DBG_BUGON(xattr_header_sz > vi->xattr_isize);
		return -ENOATTR;
	}

	inline_xattr_ofs = vi->inode_isize + xattr_header_sz;

	it->blkaddr = erofs_blknr(iloc(sbi, vi->nid) + inline_xattr_ofs);
	it->ofs = erofs_blkoff(iloc(sbi, vi->nid) + inline_xattr_ofs);

	it->kaddr = erofs_read_metabuf(&it->buf, inode->i_sb, it->blkaddr,
				       EROFS_KMAP_ATOMIC);
	if (IS_ERR(it->kaddr))
		return PTR_ERR(it->kaddr);
	return vi->xattr_isize - xattr_header_sz;
}

/*
 * Regardless of success or failure, `xattr_foreach' will end up with
 * `ofs' pointing to the next xattr item rather than an arbitrary position.
 */
static int xattr_foreach(struct xattr_iter *it,
			 const struct xattr_iter_handlers *op,
			 unsigned int *tlimit)
{
	struct erofs_xattr_entry entry;
	unsigned int value_sz, processed, slice;
	int err;

	/* 0. fixup blkaddr, ofs, ipage */
	err = xattr_iter_fixup(it);
	if (err)
		return err;

	/*
	 * 1. read xattr entry to the memory,
	 *    since we do EROFS_XATTR_ALIGN
	 *    therefore entry should be in the page
	 */
	entry = *(struct erofs_xattr_entry *)(it->kaddr + it->ofs);
	if (tlimit) {
		unsigned int entry_sz = erofs_xattr_entry_size(&entry);

		/* xattr on-disk corruption: xattr entry beyond xattr_isize */
		if (*tlimit < entry_sz) {
			DBG_BUGON(1);
			return -EFSCORRUPTED;
		}
		*tlimit -= entry_sz;
	}

	it->ofs += sizeof(struct erofs_xattr_entry);
	value_sz = le16_to_cpu(entry.e_value_size);

	/* handle entry */
	err = op->entry(it, &entry);
	if (err) {
		it->ofs += entry.e_name_len + value_sz;
		goto out;
	}

	/* 2. handle xattr name (ofs will finally be at the end of name) */
	processed = 0;

	while (processed < entry.e_name_len) {
		if (it->ofs >= EROFS_BLKSIZ) {
			DBG_BUGON(it->ofs > EROFS_BLKSIZ);

			err = xattr_iter_fixup(it);
			if (err)
				goto out;
			it->ofs = 0;
		}

		slice = min_t(unsigned int, EROFS_BLKSIZ - it->ofs,
			      entry.e_name_len - processed);

		/* handle name */
		err = op->name(it, processed, it->kaddr + it->ofs, slice);
		if (err) {
			it->ofs += entry.e_name_len - processed + value_sz;
			goto out;
		}

		it->ofs += slice;
		processed += slice;
	}

	/* 3. handle xattr value */
	processed = 0;

	if (op->alloc_buffer) {
		err = op->alloc_buffer(it, value_sz);
		if (err) {
			it->ofs += value_sz;
			goto out;
		}
	}

	while (processed < value_sz) {
		if (it->ofs >= EROFS_BLKSIZ) {
			DBG_BUGON(it->ofs > EROFS_BLKSIZ);

			err = xattr_iter_fixup(it);
			if (err)
				goto out;
			it->ofs = 0;
		}

		slice = min_t(unsigned int, EROFS_BLKSIZ - it->ofs,
			      value_sz - processed);
		op->value(it, processed, it->kaddr + it->ofs, slice);
		it->ofs += slice;
		processed += slice;
	}

out:
	/* xattrs should be 4-byte aligned (on-disk constraint) */
	it->ofs = EROFS_XATTR_ALIGN(it->ofs);
	return err < 0 ? err : 0;
}

struct getxattr_iter {
	struct xattr_iter it;

	char *buffer;
	int buffer_size, index;
	struct qstr name;
};

static int xattr_entrymatch(struct xattr_iter *_it,
			    struct erofs_xattr_entry *entry)
{
	struct getxattr_iter *it = container_of(_it, struct getxattr_iter, it);

	return (it->index != entry->e_name_index ||
		it->name.len != entry->e_name_len) ? -ENOATTR : 0;
}

static int xattr_namematch(struct xattr_iter *_it,
			   unsigned int processed, char *buf, unsigned int len)
{
	struct getxattr_iter *it = container_of(_it, struct getxattr_iter, it);

	return memcmp(buf, it->name.name + processed, len) ? -ENOATTR : 0;
}

static int xattr_checkbuffer(struct xattr_iter *_it,
			     unsigned int value_sz)
{
	struct getxattr_iter *it = container_of(_it, struct getxattr_iter, it);
	int err = it->buffer_size < value_sz ? -ERANGE : 0;

	it->buffer_size = value_sz;
	return !it->buffer ? 1 : err;
}

static void xattr_copyvalue(struct xattr_iter *_it,
			    unsigned int processed,
			    char *buf, unsigned int len)
{
	struct getxattr_iter *it = container_of(_it, struct getxattr_iter, it);

	memcpy(it->buffer + processed, buf, len);
}

static const struct xattr_iter_handlers find_xattr_handlers = {
	.entry = xattr_entrymatch,
	.name = xattr_namematch,
	.alloc_buffer = xattr_checkbuffer,
	.value = xattr_copyvalue
};

static int inline_getxattr(struct inode *inode, struct getxattr_iter *it)
{
	int ret;
	unsigned int remaining;

	ret = inline_xattr_iter_begin(&it->it, inode);
	if (ret < 0)
		return ret;

	remaining = ret;
	while (remaining) {
		ret = xattr_foreach(&it->it, &find_xattr_handlers, &remaining);
		if (ret != -ENOATTR)
			break;
	}
	return ret ? ret : it->buffer_size;
}

static int shared_getxattr(struct inode *inode, struct getxattr_iter *it)
{
	struct erofs_inode *const vi = EROFS_I(inode);
	struct super_block *const sb = inode->i_sb;
	struct erofs_sb_info *const sbi = EROFS_SB(sb);
	unsigned int i;
	int ret = -ENOATTR;

	for (i = 0; i < vi->xattr_shared_count; ++i) {
		erofs_blk_t blkaddr =
			xattrblock_addr(sbi, vi->xattr_shared_xattrs[i]);

		it->it.ofs = xattrblock_offset(sbi, vi->xattr_shared_xattrs[i]);
		it->it.kaddr = erofs_read_metabuf(&it->it.buf, sb, blkaddr,
						  EROFS_KMAP_ATOMIC);
		if (IS_ERR(it->it.kaddr))
			return PTR_ERR(it->it.kaddr);
		it->it.blkaddr = blkaddr;

		ret = xattr_foreach(&it->it, &find_xattr_handlers, NULL);
		if (ret != -ENOATTR)
			break;
	}
	return ret ? ret : it->buffer_size;
}

static bool erofs_xattr_user_list(struct dentry *dentry)
{
	return test_opt(&EROFS_SB(dentry->d_sb)->opt, XATTR_USER);
}

static bool erofs_xattr_trusted_list(struct dentry *dentry)
{
	return capable(CAP_SYS_ADMIN);
}

int erofs_getxattr(struct inode *inode, int index,
		   const char *name,
		   void *buffer, size_t buffer_size)
{
	int ret;
	struct getxattr_iter it;

	if (!name)
		return -EINVAL;

	ret = init_inode_xattrs(inode);
	if (ret)
		return ret;

	it.index = index;
	it.name.len = strlen(name);
	if (it.name.len > EROFS_NAME_LEN)
		return -ERANGE;

	it.it.buf = __EROFS_BUF_INITIALIZER;
	it.name.name = name;

	it.buffer = buffer;
	it.buffer_size = buffer_size;

	it.it.sb = inode->i_sb;
	ret = inline_getxattr(inode, &it);
	if (ret == -ENOATTR)
		ret = shared_getxattr(inode, &it);
	erofs_put_metabuf(&it.it.buf);
	return ret;
}

static int erofs_xattr_generic_get(const struct xattr_handler *handler,
				   struct dentry *unused, struct inode *inode,
				   const char *name, void *buffer, size_t size)
{
	struct erofs_sb_info *const sbi = EROFS_I_SB(inode);

	switch (handler->flags) {
	case EROFS_XATTR_INDEX_USER:
		if (!test_opt(&sbi->opt, XATTR_USER))
			return -EOPNOTSUPP;
		break;
	case EROFS_XATTR_INDEX_TRUSTED:
		break;
	case EROFS_XATTR_INDEX_SECURITY:
		break;
	default:
		return -EINVAL;
	}

	return erofs_getxattr(inode, handler->flags, name, buffer, size);
}

const struct xattr_handler erofs_xattr_user_handler = {
	.prefix	= XATTR_USER_PREFIX,
	.flags	= EROFS_XATTR_INDEX_USER,
	.list	= erofs_xattr_user_list,
	.get	= erofs_xattr_generic_get,
};

const struct xattr_handler erofs_xattr_trusted_handler = {
	.prefix	= XATTR_TRUSTED_PREFIX,
	.flags	= EROFS_XATTR_INDEX_TRUSTED,
	.list	= erofs_xattr_trusted_list,
	.get	= erofs_xattr_generic_get,
};

#ifdef CONFIG_EROFS_FS_SECURITY
const struct xattr_handler __maybe_unused erofs_xattr_security_handler = {
	.prefix	= XATTR_SECURITY_PREFIX,
	.flags	= EROFS_XATTR_INDEX_SECURITY,
	.get	= erofs_xattr_generic_get,
};
#endif

const struct xattr_handler *erofs_xattr_handlers[] = {
	&erofs_xattr_user_handler,
#ifdef CONFIG_EROFS_FS_POSIX_ACL
	&posix_acl_access_xattr_handler,
	&posix_acl_default_xattr_handler,
#endif
	&erofs_xattr_trusted_handler,
#ifdef CONFIG_EROFS_FS_SECURITY
	&erofs_xattr_security_handler,
#endif
	NULL,
};

struct listxattr_iter {
	struct xattr_iter it;

	struct dentry *dentry;
	char *buffer;
	int buffer_size, buffer_ofs;
};

static int xattr_entrylist(struct xattr_iter *_it,
			   struct erofs_xattr_entry *entry)
{
	struct listxattr_iter *it =
		container_of(_it, struct listxattr_iter, it);
	unsigned int prefix_len;
	const char *prefix;

	const struct xattr_handler *h =
		erofs_xattr_handler(entry->e_name_index);

	if (!h || (h->list && !h->list(it->dentry)))
		return 1;

	prefix = xattr_prefix(h);
	prefix_len = strlen(prefix);

	if (!it->buffer) {
		it->buffer_ofs += prefix_len + entry->e_name_len + 1;
		return 1;
	}

	if (it->buffer_ofs + prefix_len
		+ entry->e_name_len + 1 > it->buffer_size)
		return -ERANGE;

	memcpy(it->buffer + it->buffer_ofs, prefix, prefix_len);
	it->buffer_ofs += prefix_len;
	return 0;
}

static int xattr_namelist(struct xattr_iter *_it,
			  unsigned int processed, char *buf, unsigned int len)
{
	struct listxattr_iter *it =
		container_of(_it, struct listxattr_iter, it);

	memcpy(it->buffer + it->buffer_ofs, buf, len);
	it->buffer_ofs += len;
	return 0;
}

static int xattr_skipvalue(struct xattr_iter *_it,
			   unsigned int value_sz)
{
	struct listxattr_iter *it =
		container_of(_it, struct listxattr_iter, it);

	it->buffer[it->buffer_ofs++] = '\0';
	return 1;
}

static const struct xattr_iter_handlers list_xattr_handlers = {
	.entry = xattr_entrylist,
	.name = xattr_namelist,
	.alloc_buffer = xattr_skipvalue,
	.value = NULL
};

static int inline_listxattr(struct listxattr_iter *it)
{
	int ret;
	unsigned int remaining;

	ret = inline_xattr_iter_begin(&it->it, d_inode(it->dentry));
	if (ret < 0)
		return ret;

	remaining = ret;
	while (remaining) {
		ret = xattr_foreach(&it->it, &list_xattr_handlers, &remaining);
		if (ret)
			break;
	}
	return ret ? ret : it->buffer_ofs;
}

static int shared_listxattr(struct listxattr_iter *it)
{
	struct inode *const inode = d_inode(it->dentry);
	struct erofs_inode *const vi = EROFS_I(inode);
	struct super_block *const sb = inode->i_sb;
	struct erofs_sb_info *const sbi = EROFS_SB(sb);
	unsigned int i;
	int ret = 0;

	for (i = 0; i < vi->xattr_shared_count; ++i) {
		erofs_blk_t blkaddr =
			xattrblock_addr(sbi, vi->xattr_shared_xattrs[i]);

		it->it.ofs = xattrblock_offset(sbi, vi->xattr_shared_xattrs[i]);
		it->it.kaddr = erofs_read_metabuf(&it->it.buf, sb, blkaddr,
						  EROFS_KMAP_ATOMIC);
		if (IS_ERR(it->it.kaddr))
			return PTR_ERR(it->it.kaddr);
		it->it.blkaddr = blkaddr;

		ret = xattr_foreach(&it->it, &list_xattr_handlers, NULL);
		if (ret)
			break;
	}
	return ret ? ret : it->buffer_ofs;
}

ssize_t erofs_listxattr(struct dentry *dentry,
			char *buffer, size_t buffer_size)
{
	int ret;
	struct listxattr_iter it;

	ret = init_inode_xattrs(d_inode(dentry));
	if (ret == -ENOATTR)
		return 0;
	if (ret)
		return ret;

	it.it.buf = __EROFS_BUF_INITIALIZER;
	it.dentry = dentry;
	it.buffer = buffer;
	it.buffer_size = buffer_size;
	it.buffer_ofs = 0;

	it.it.sb = dentry->d_sb;

	ret = inline_listxattr(&it);
	if (ret >= 0 || ret == -ENOATTR)
		ret = shared_listxattr(&it);
	erofs_put_metabuf(&it.it.buf);
	return ret;
}

#ifdef CONFIG_EROFS_FS_POSIX_ACL
struct posix_acl *erofs_get_acl(struct inode *inode, int type, bool rcu)
{
	struct posix_acl *acl;
	int prefix, rc;
	char *value = NULL;

	if (rcu)
		return ERR_PTR(-ECHILD);

	switch (type) {
	case ACL_TYPE_ACCESS:
		prefix = EROFS_XATTR_INDEX_POSIX_ACL_ACCESS;
		break;
	case ACL_TYPE_DEFAULT:
		prefix = EROFS_XATTR_INDEX_POSIX_ACL_DEFAULT;
		break;
	default:
		return ERR_PTR(-EINVAL);
	}

	rc = erofs_getxattr(inode, prefix, "", NULL, 0);
	if (rc > 0) {
		value = kmalloc(rc, GFP_KERNEL);
		if (!value)
			return ERR_PTR(-ENOMEM);
		rc = erofs_getxattr(inode, prefix, "", value, rc);
	}

	if (rc == -ENOATTR)
		acl = NULL;
	else if (rc < 0)
		acl = ERR_PTR(rc);
	else
		acl = posix_acl_from_xattr(&init_user_ns, value, rc);
	kfree(value);
	return acl;
}
#endif
Commit	Line	Data
29b24f6c	1	// SPDX-License-Identifier: GPL-2.0-only
b17500a0	2	/*
b17500a0	3	* Copyright (C) 2017-2018 HUAWEI, Inc.
592e7cd0	4	* https://www.huawei.com/
bb88e8da	5	* Copyright (C) 2021-2022, Alibaba Cloud
b17500a0 GX	6	*/
	7	#include <linux/security.h>
	8	#include "xattr.h"
	9
	10	struct xattr_iter {
	11	struct super_block *sb;
bb88e8da	12	struct erofs_buf buf;
b17500a0 GX	13	void *kaddr;
	14
	15	erofs_blk_t blkaddr;
7dd68b14	16	unsigned int ofs;
b17500a0 GX	17	};
b17500a0 GX	18
cadf1ccf	19	static int init_inode_xattrs(struct inode *inode)
b17500a0	20	{
a5876e24	21	struct erofs_inode *const vi = EROFS_I(inode);
b17500a0	22	struct xattr_iter it;
7dd68b14	23	unsigned int i;
b17500a0	24	struct erofs_xattr_ibody_header *ih;
6e78901a	25	struct super_block *sb;
b17500a0	26	struct erofs_sb_info *sbi;
62dc4597	27	int ret = 0;
b17500a0	28
62dc4597	29	/* the most case is that xattrs of this inode are initialized. */
ce063129 GX	30	if (test_bit(EROFS_I_EA_INITED_BIT, &vi->flags)) {
	31	/*
	32	* paired with smp_mb() at the end of the function to ensure
	33	* fields will only be observed after the bit is set.
	34	*/
	35	smp_mb();
cadf1ccf	36	return 0;
ce063129	37	}
b17500a0	38
a5876e24	39	if (wait_on_bit_lock(&vi->flags, EROFS_I_BL_XATTR_BIT, TASK_KILLABLE))
62dc4597 GX	40	return -ERESTARTSYS;
	41
	42	/* someone has initialized xattrs for us? */
a5876e24	43	if (test_bit(EROFS_I_EA_INITED_BIT, &vi->flags))
62dc4597	44	goto out_unlock;
7077fffc GX	45
	46	/*
	47	* bypass all xattr operations if ->xattr_isize is not greater than
	48	* sizeof(struct erofs_xattr_ibody_header), in detail:
	49	* 1) it is not enough to contain erofs_xattr_ibody_header then
	50	* ->xattr_isize should be 0 (it means no xattr);
	51	* 2) it is just to contain erofs_xattr_ibody_header, which is on-disk
	52	* undefined right now (maybe use later with some new sb feature).
	53	*/
	54	if (vi->xattr_isize == sizeof(struct erofs_xattr_ibody_header)) {
4f761fa2 GX	55	erofs_err(inode->i_sb,
	56	"xattr_isize %d of nid %llu is not supported yet",
	57	vi->xattr_isize, vi->nid);
ff784a78	58	ret = -EOPNOTSUPP;
62dc4597	59	goto out_unlock;
7077fffc	60	} else if (vi->xattr_isize < sizeof(struct erofs_xattr_ibody_header)) {
8d8a09b0	61	if (vi->xattr_isize) {
4f761fa2 GX	62	erofs_err(inode->i_sb,
4f761fa2 GX	63	"bogus xattr ibody @ nid %llu", vi->nid);
7077fffc	64	DBG_BUGON(1);
a6b9b1d5	65	ret = -EFSCORRUPTED;
62dc4597	66	goto out_unlock; /* xattr ondisk layout error */
7077fffc	67	}
62dc4597 GX	68	ret = -ENOATTR;
62dc4597 GX	69	goto out_unlock;
7077fffc	70	}
b17500a0	71
6e78901a GX	72	sb = inode->i_sb;
6e78901a GX	73	sbi = EROFS_SB(sb);
bb88e8da	74	it.buf = __EROFS_BUF_INITIALIZER;
b17500a0 GX	75	it.blkaddr = erofs_blknr(iloc(sbi, vi->nid) + vi->inode_isize);
	76	it.ofs = erofs_blkoff(iloc(sbi, vi->nid) + vi->inode_isize);
	77
bb88e8da GX	78	/* read in shared xattr array (non-atomic, see kmalloc below) */
	79	it.kaddr = erofs_read_metabuf(&it.buf, sb, it.blkaddr, EROFS_KMAP);
	80	if (IS_ERR(it.kaddr)) {
	81	ret = PTR_ERR(it.kaddr);
62dc4597 GX	82	goto out_unlock;
62dc4597 GX	83	}
b17500a0	84
b17500a0	85	ih = (struct erofs_xattr_ibody_header *)(it.kaddr + it.ofs);
b17500a0	86	vi->xattr_shared_count = ih->h_shared_count;
cadf1ccf GX	87	vi->xattr_shared_xattrs = kmalloc_array(vi->xattr_shared_count,
cadf1ccf GX	88	sizeof(uint), GFP_KERNEL);
561fb35a	89	if (!vi->xattr_shared_xattrs) {
bb88e8da	90	erofs_put_metabuf(&it.buf);
62dc4597 GX	91	ret = -ENOMEM;
62dc4597 GX	92	goto out_unlock;
cadf1ccf	93	}
b17500a0 GX	94
	95	/* let's skip ibody header */
	96	it.ofs += sizeof(struct erofs_xattr_ibody_header);
	97
	98	for (i = 0; i < vi->xattr_shared_count; ++i) {
8d8a09b0	99	if (it.ofs >= EROFS_BLKSIZ) {
b17500a0	100	/* cannot be unaligned */
9ddc7004	101	DBG_BUGON(it.ofs != EROFS_BLKSIZ);
b17500a0	102
bb88e8da GX	103	it.kaddr = erofs_read_metabuf(&it.buf, sb, ++it.blkaddr,
	104	EROFS_KMAP);
	105	if (IS_ERR(it.kaddr)) {
3b1b5291 SY	106	kfree(vi->xattr_shared_xattrs);
3b1b5291 SY	107	vi->xattr_shared_xattrs = NULL;
bb88e8da	108	ret = PTR_ERR(it.kaddr);
62dc4597	109	goto out_unlock;
3b1b5291	110	}
b17500a0 GX	111	it.ofs = 0;
	112	}
	113	vi->xattr_shared_xattrs[i] =
	114	le32_to_cpu((__le32 )(it.kaddr + it.ofs));
	115	it.ofs += sizeof(__le32);
	116	}
bb88e8da	117	erofs_put_metabuf(&it.buf);
b17500a0	118
ce063129 GX	119	/* paired with smp_mb() at the beginning of the function. */
ce063129 GX	120	smp_mb();
a5876e24	121	set_bit(EROFS_I_EA_INITED_BIT, &vi->flags);
62dc4597 GX	122
62dc4597 GX	123	out_unlock:
a5876e24	124	clear_and_wake_up_bit(EROFS_I_BL_XATTR_BIT, &vi->flags);
62dc4597	125	return ret;
b17500a0 GX	126	}
b17500a0 GX	127
bdf30cef GX	128	/*
	129	* the general idea for these return values is
	130	* if 0 is returned, go on processing the current xattr;
	131	* 1 (> 0) is returned, skip this round to process the next xattr;
	132	* -err (< 0) is returned, an error (maybe ENOXATTR) occurred
	133	* and need to be handled
	134	*/
b17500a0	135	struct xattr_iter_handlers {
4b03f3f4 SY	136	int (entry)(struct xattr_iter _it, struct erofs_xattr_entry *entry);
	137	int (name)(struct xattr_iter _it, unsigned int processed, char *buf,
	138	unsigned int len);
	139	int (alloc_buffer)(struct xattr_iter _it, unsigned int value_sz);
	140	void (value)(struct xattr_iter _it, unsigned int processed, char *buf,
	141	unsigned int len);
b17500a0 GX	142	};
b17500a0 GX	143
cadf1ccf	144	static inline int xattr_iter_fixup(struct xattr_iter *it)
b17500a0	145	{
cadf1ccf GX	146	if (it->ofs < EROFS_BLKSIZ)
	147	return 0;
	148
cadf1ccf	149	it->blkaddr += erofs_blknr(it->ofs);
bb88e8da GX	150	it->kaddr = erofs_read_metabuf(&it->buf, it->sb, it->blkaddr,
	151	EROFS_KMAP_ATOMIC);
	152	if (IS_ERR(it->kaddr))
	153	return PTR_ERR(it->kaddr);
cadf1ccf GX	154	it->ofs = erofs_blkoff(it->ofs);
cadf1ccf GX	155	return 0;
b17500a0 GX	156	}
	157
	158	static int inline_xattr_iter_begin(struct xattr_iter *it,
447a3621	159	struct inode *inode)
b17500a0	160	{
a5876e24	161	struct erofs_inode *const vi = EROFS_I(inode);
b17500a0	162	struct erofs_sb_info *const sbi = EROFS_SB(inode->i_sb);
7dd68b14	163	unsigned int xattr_header_sz, inline_xattr_ofs;
b17500a0 GX	164
b17500a0 GX	165	xattr_header_sz = inlinexattr_header_size(inode);
8d8a09b0	166	if (xattr_header_sz >= vi->xattr_isize) {
9ddc7004	167	DBG_BUGON(xattr_header_sz > vi->xattr_isize);
b17500a0 GX	168	return -ENOATTR;
	169	}
	170
	171	inline_xattr_ofs = vi->inode_isize + xattr_header_sz;
	172
	173	it->blkaddr = erofs_blknr(iloc(sbi, vi->nid) + inline_xattr_ofs);
	174	it->ofs = erofs_blkoff(iloc(sbi, vi->nid) + inline_xattr_ofs);
	175
bb88e8da GX	176	it->kaddr = erofs_read_metabuf(&it->buf, inode->i_sb, it->blkaddr,
	177	EROFS_KMAP_ATOMIC);
	178	if (IS_ERR(it->kaddr))
	179	return PTR_ERR(it->kaddr);
b17500a0 GX	180	return vi->xattr_isize - xattr_header_sz;
	181	}
	182
bdf30cef GX	183	/*
	184	* Regardless of success or failure, `xattr_foreach' will end up with
	185	* `ofs' pointing to the next xattr item rather than an arbitrary position.
	186	*/
b17500a0	187	static int xattr_foreach(struct xattr_iter *it,
447a3621 JM	188	const struct xattr_iter_handlers *op,
447a3621 JM	189	unsigned int *tlimit)
b17500a0 GX	190	{
b17500a0 GX	191	struct erofs_xattr_entry entry;
7dd68b14	192	unsigned int value_sz, processed, slice;
b17500a0 GX	193	int err;
	194
	195	/* 0. fixup blkaddr, ofs, ipage */
cadf1ccf GX	196	err = xattr_iter_fixup(it);
	197	if (err)
	198	return err;
b17500a0 GX	199
	200	/*
	201	* 1. read xattr entry to the memory,
	202	* since we do EROFS_XATTR_ALIGN
	203	* therefore entry should be in the page
	204	*/
	205	entry = (struct erofs_xattr_entry )(it->kaddr + it->ofs);
561fb35a	206	if (tlimit) {
b6796abd	207	unsigned int entry_sz = erofs_xattr_entry_size(&entry);
b17500a0	208
9ddc7004	209	/* xattr on-disk corruption: xattr entry beyond xattr_isize */
8d8a09b0	210	if (*tlimit < entry_sz) {
9ddc7004	211	DBG_BUGON(1);
a6b9b1d5	212	return -EFSCORRUPTED;
9ddc7004	213	}
b17500a0 GX	214	*tlimit -= entry_sz;
	215	}
	216
	217	it->ofs += sizeof(struct erofs_xattr_entry);
	218	value_sz = le16_to_cpu(entry.e_value_size);
	219
	220	/* handle entry */
	221	err = op->entry(it, &entry);
	222	if (err) {
	223	it->ofs += entry.e_name_len + value_sz;
	224	goto out;
	225	}
	226
	227	/* 2. handle xattr name (ofs will finally be at the end of name) */
	228	processed = 0;
	229
	230	while (processed < entry.e_name_len) {
	231	if (it->ofs >= EROFS_BLKSIZ) {
9ddc7004	232	DBG_BUGON(it->ofs > EROFS_BLKSIZ);
b17500a0	233
cadf1ccf GX	234	err = xattr_iter_fixup(it);
	235	if (err)
	236	goto out;
b17500a0 GX	237	it->ofs = 0;
	238	}
	239
bb88e8da	240	slice = min_t(unsigned int, EROFS_BLKSIZ - it->ofs,
7dd68b14	241	entry.e_name_len - processed);
b17500a0 GX	242
	243	/* handle name */
	244	err = op->name(it, processed, it->kaddr + it->ofs, slice);
	245	if (err) {
	246	it->ofs += entry.e_name_len - processed + value_sz;
	247	goto out;
	248	}
	249
	250	it->ofs += slice;
	251	processed += slice;
	252	}
	253
	254	/* 3. handle xattr value */
	255	processed = 0;
	256
561fb35a	257	if (op->alloc_buffer) {
b17500a0 GX	258	err = op->alloc_buffer(it, value_sz);
	259	if (err) {
	260	it->ofs += value_sz;
	261	goto out;
	262	}
	263	}
	264
	265	while (processed < value_sz) {
	266	if (it->ofs >= EROFS_BLKSIZ) {
9ddc7004	267	DBG_BUGON(it->ofs > EROFS_BLKSIZ);
cadf1ccf GX	268
	269	err = xattr_iter_fixup(it);
	270	if (err)
	271	goto out;
b17500a0 GX	272	it->ofs = 0;
	273	}
	274
bb88e8da	275	slice = min_t(unsigned int, EROFS_BLKSIZ - it->ofs,
7dd68b14	276	value_sz - processed);
b17500a0 GX	277	op->value(it, processed, it->kaddr + it->ofs, slice);
	278	it->ofs += slice;
	279	processed += slice;
	280	}
	281
	282	out:
bdf30cef	283	/* xattrs should be 4-byte aligned (on-disk constraint) */
b17500a0	284	it->ofs = EROFS_XATTR_ALIGN(it->ofs);
6614f765	285	return err < 0 ? err : 0;
b17500a0 GX	286	}
	287
	288	struct getxattr_iter {
	289	struct xattr_iter it;
	290
	291	char *buffer;
	292	int buffer_size, index;
	293	struct qstr name;
	294	};
	295
	296	static int xattr_entrymatch(struct xattr_iter *_it,
447a3621	297	struct erofs_xattr_entry *entry)
b17500a0 GX	298	{
	299	struct getxattr_iter *it = container_of(_it, struct getxattr_iter, it);
	300
	301	return (it->index != entry->e_name_index \|\|
	302	it->name.len != entry->e_name_len) ? -ENOATTR : 0;
	303	}
	304
	305	static int xattr_namematch(struct xattr_iter *_it,
447a3621	306	unsigned int processed, char *buf, unsigned int len)
b17500a0 GX	307	{
	308	struct getxattr_iter *it = container_of(_it, struct getxattr_iter, it);
	309
	310	return memcmp(buf, it->name.name + processed, len) ? -ENOATTR : 0;
	311	}
	312
	313	static int xattr_checkbuffer(struct xattr_iter *_it,
447a3621	314	unsigned int value_sz)
b17500a0 GX	315	{
	316	struct getxattr_iter *it = container_of(_it, struct getxattr_iter, it);
	317	int err = it->buffer_size < value_sz ? -ERANGE : 0;
	318
	319	it->buffer_size = value_sz;
561fb35a	320	return !it->buffer ? 1 : err;
b17500a0 GX	321	}
	322
	323	static void xattr_copyvalue(struct xattr_iter *_it,
447a3621 JM	324	unsigned int processed,
447a3621 JM	325	char *buf, unsigned int len)
b17500a0 GX	326	{
	327	struct getxattr_iter *it = container_of(_it, struct getxattr_iter, it);
	328
	329	memcpy(it->buffer + processed, buf, len);
	330	}
	331
cadf1ccf	332	static const struct xattr_iter_handlers find_xattr_handlers = {
b17500a0 GX	333	.entry = xattr_entrymatch,
	334	.name = xattr_namematch,
	335	.alloc_buffer = xattr_checkbuffer,
	336	.value = xattr_copyvalue
	337	};
	338
	339	static int inline_getxattr(struct inode inode, struct getxattr_iter it)
	340	{
	341	int ret;
7dd68b14	342	unsigned int remaining;
b17500a0 GX	343
	344	ret = inline_xattr_iter_begin(&it->it, inode);
	345	if (ret < 0)
	346	return ret;
	347
	348	remaining = ret;
	349	while (remaining) {
2bc75964	350	ret = xattr_foreach(&it->it, &find_xattr_handlers, &remaining);
6614f765	351	if (ret != -ENOATTR)
cadf1ccf	352	break;
b17500a0	353	}
6614f765	354	return ret ? ret : it->buffer_size;
b17500a0 GX	355	}
	356
	357	static int shared_getxattr(struct inode inode, struct getxattr_iter it)
	358	{
a5876e24	359	struct erofs_inode *const vi = EROFS_I(inode);
6e78901a GX	360	struct super_block *const sb = inode->i_sb;
6e78901a GX	361	struct erofs_sb_info *const sbi = EROFS_SB(sb);
7dd68b14	362	unsigned int i;
b17500a0 GX	363	int ret = -ENOATTR;
	364
	365	for (i = 0; i < vi->xattr_shared_count; ++i) {
	366	erofs_blk_t blkaddr =
	367	xattrblock_addr(sbi, vi->xattr_shared_xattrs[i]);
	368
	369	it->it.ofs = xattrblock_offset(sbi, vi->xattr_shared_xattrs[i]);
bb88e8da GX	370	it->it.kaddr = erofs_read_metabuf(&it->it.buf, sb, blkaddr,
	371	EROFS_KMAP_ATOMIC);
	372	if (IS_ERR(it->it.kaddr))
	373	return PTR_ERR(it->it.kaddr);
	374	it->it.blkaddr = blkaddr;
b17500a0	375
2bc75964	376	ret = xattr_foreach(&it->it, &find_xattr_handlers, NULL);
6614f765	377	if (ret != -ENOATTR)
cadf1ccf	378	break;
b17500a0	379	}
6614f765	380	return ret ? ret : it->buffer_size;
b17500a0 GX	381	}
	382
	383	static bool erofs_xattr_user_list(struct dentry *dentry)
	384	{
e6242465	385	return test_opt(&EROFS_SB(dentry->d_sb)->opt, XATTR_USER);
b17500a0 GX	386	}
	387
	388	static bool erofs_xattr_trusted_list(struct dentry *dentry)
	389	{
	390	return capable(CAP_SYS_ADMIN);
	391	}
	392
	393	int erofs_getxattr(struct inode *inode, int index,
447a3621 JM	394	const char *name,
447a3621 JM	395	void *buffer, size_t buffer_size)
b17500a0 GX	396	{
	397	int ret;
	398	struct getxattr_iter it;
	399
8d8a09b0	400	if (!name)
b17500a0 GX	401	return -EINVAL;
b17500a0 GX	402
cadf1ccf GX	403	ret = init_inode_xattrs(inode);
	404	if (ret)
	405	return ret;
b17500a0 GX	406
b17500a0 GX	407	it.index = index;
b17500a0 GX	408	it.name.len = strlen(name);
	409	if (it.name.len > EROFS_NAME_LEN)
	410	return -ERANGE;
bb88e8da GX	411
bb88e8da GX	412	it.it.buf = __EROFS_BUF_INITIALIZER;
b17500a0 GX	413	it.name.name = name;
	414
	415	it.buffer = buffer;
	416	it.buffer_size = buffer_size;
	417
	418	it.it.sb = inode->i_sb;
	419	ret = inline_getxattr(inode, &it);
	420	if (ret == -ENOATTR)
	421	ret = shared_getxattr(inode, &it);
bb88e8da	422	erofs_put_metabuf(&it.it.buf);
b17500a0 GX	423	return ret;
	424	}
	425
	426	static int erofs_xattr_generic_get(const struct xattr_handler *handler,
447a3621 JM	427	struct dentry unused, struct inode inode,
447a3621 JM	428	const char name, void buffer, size_t size)
b17500a0	429	{
b17500a0 GX	430	struct erofs_sb_info *const sbi = EROFS_I_SB(inode);
	431
	432	switch (handler->flags) {
	433	case EROFS_XATTR_INDEX_USER:
e6242465	434	if (!test_opt(&sbi->opt, XATTR_USER))
b17500a0 GX	435	return -EOPNOTSUPP;
	436	break;
	437	case EROFS_XATTR_INDEX_TRUSTED:
b17500a0 GX	438	break;
	439	case EROFS_XATTR_INDEX_SECURITY:
	440	break;
	441	default:
	442	return -EINVAL;
	443	}
	444
b17500a0 GX	445	return erofs_getxattr(inode, handler->flags, name, buffer, size);
	446	}
	447
	448	const struct xattr_handler erofs_xattr_user_handler = {
	449	.prefix = XATTR_USER_PREFIX,
	450	.flags = EROFS_XATTR_INDEX_USER,
	451	.list = erofs_xattr_user_list,
	452	.get = erofs_xattr_generic_get,
	453	};
	454
	455	const struct xattr_handler erofs_xattr_trusted_handler = {
	456	.prefix = XATTR_TRUSTED_PREFIX,
	457	.flags = EROFS_XATTR_INDEX_TRUSTED,
	458	.list = erofs_xattr_trusted_list,
	459	.get = erofs_xattr_generic_get,
	460	};
	461
	462	#ifdef CONFIG_EROFS_FS_SECURITY
	463	const struct xattr_handler __maybe_unused erofs_xattr_security_handler = {
	464	.prefix = XATTR_SECURITY_PREFIX,
	465	.flags = EROFS_XATTR_INDEX_SECURITY,
	466	.get = erofs_xattr_generic_get,
	467	};
	468	#endif
	469
b17500a0 GX	470	const struct xattr_handler *erofs_xattr_handlers[] = {
	471	&erofs_xattr_user_handler,
	472	#ifdef CONFIG_EROFS_FS_POSIX_ACL
	473	&posix_acl_access_xattr_handler,
	474	&posix_acl_default_xattr_handler,
	475	#endif
	476	&erofs_xattr_trusted_handler,
	477	#ifdef CONFIG_EROFS_FS_SECURITY
	478	&erofs_xattr_security_handler,
	479	#endif
	480	NULL,
	481	};
b17500a0 GX	482
	483	struct listxattr_iter {
	484	struct xattr_iter it;
	485
	486	struct dentry *dentry;
	487	char *buffer;
	488	int buffer_size, buffer_ofs;
	489	};
	490
	491	static int xattr_entrylist(struct xattr_iter *_it,
447a3621	492	struct erofs_xattr_entry *entry)
b17500a0 GX	493	{
	494	struct listxattr_iter *it =
	495	container_of(_it, struct listxattr_iter, it);
7dd68b14	496	unsigned int prefix_len;
b17500a0 GX	497	const char *prefix;
	498
	499	const struct xattr_handler *h =
	500	erofs_xattr_handler(entry->e_name_index);
	501
561fb35a	502	if (!h \|\| (h->list && !h->list(it->dentry)))
b17500a0 GX	503	return 1;
b17500a0 GX	504
a24df1f6	505	prefix = xattr_prefix(h);
b17500a0 GX	506	prefix_len = strlen(prefix);
b17500a0 GX	507
561fb35a	508	if (!it->buffer) {
b17500a0 GX	509	it->buffer_ofs += prefix_len + entry->e_name_len + 1;
	510	return 1;
	511	}
	512
	513	if (it->buffer_ofs + prefix_len
	514	+ entry->e_name_len + 1 > it->buffer_size)
	515	return -ERANGE;
	516
	517	memcpy(it->buffer + it->buffer_ofs, prefix, prefix_len);
	518	it->buffer_ofs += prefix_len;
	519	return 0;
	520	}
	521
	522	static int xattr_namelist(struct xattr_iter *_it,
447a3621	523	unsigned int processed, char *buf, unsigned int len)
b17500a0 GX	524	{
	525	struct listxattr_iter *it =
	526	container_of(_it, struct listxattr_iter, it);
	527
	528	memcpy(it->buffer + it->buffer_ofs, buf, len);
	529	it->buffer_ofs += len;
	530	return 0;
	531	}
	532
	533	static int xattr_skipvalue(struct xattr_iter *_it,
447a3621	534	unsigned int value_sz)
b17500a0 GX	535	{
	536	struct listxattr_iter *it =
	537	container_of(_it, struct listxattr_iter, it);
	538
	539	it->buffer[it->buffer_ofs++] = '\0';
	540	return 1;
	541	}
	542
cadf1ccf	543	static const struct xattr_iter_handlers list_xattr_handlers = {
b17500a0 GX	544	.entry = xattr_entrylist,
	545	.name = xattr_namelist,
	546	.alloc_buffer = xattr_skipvalue,
	547	.value = NULL
	548	};
	549
	550	static int inline_listxattr(struct listxattr_iter *it)
	551	{
	552	int ret;
7dd68b14	553	unsigned int remaining;
b17500a0 GX	554
	555	ret = inline_xattr_iter_begin(&it->it, d_inode(it->dentry));
	556	if (ret < 0)
	557	return ret;
	558
	559	remaining = ret;
	560	while (remaining) {
2bc75964	561	ret = xattr_foreach(&it->it, &list_xattr_handlers, &remaining);
6614f765	562	if (ret)
b17500a0 GX	563	break;
b17500a0 GX	564	}
6614f765	565	return ret ? ret : it->buffer_ofs;
b17500a0 GX	566	}
	567
	568	static int shared_listxattr(struct listxattr_iter *it)
	569	{
	570	struct inode *const inode = d_inode(it->dentry);
a5876e24	571	struct erofs_inode *const vi = EROFS_I(inode);
6e78901a GX	572	struct super_block *const sb = inode->i_sb;
6e78901a GX	573	struct erofs_sb_info *const sbi = EROFS_SB(sb);
7dd68b14	574	unsigned int i;
b17500a0 GX	575	int ret = 0;
	576
	577	for (i = 0; i < vi->xattr_shared_count; ++i) {
	578	erofs_blk_t blkaddr =
	579	xattrblock_addr(sbi, vi->xattr_shared_xattrs[i]);
	580
	581	it->it.ofs = xattrblock_offset(sbi, vi->xattr_shared_xattrs[i]);
bb88e8da GX	582	it->it.kaddr = erofs_read_metabuf(&it->it.buf, sb, blkaddr,
	583	EROFS_KMAP_ATOMIC);
	584	if (IS_ERR(it->it.kaddr))
	585	return PTR_ERR(it->it.kaddr);
	586	it->it.blkaddr = blkaddr;
b17500a0	587
2bc75964	588	ret = xattr_foreach(&it->it, &list_xattr_handlers, NULL);
6614f765	589	if (ret)
b17500a0 GX	590	break;
b17500a0 GX	591	}
6614f765	592	return ret ? ret : it->buffer_ofs;
b17500a0 GX	593	}
	594
	595	ssize_t erofs_listxattr(struct dentry *dentry,
447a3621	596	char *buffer, size_t buffer_size)
b17500a0 GX	597	{
	598	int ret;
	599	struct listxattr_iter it;
	600
cadf1ccf	601	ret = init_inode_xattrs(d_inode(dentry));
926d1650 GX	602	if (ret == -ENOATTR)
926d1650 GX	603	return 0;
cadf1ccf GX	604	if (ret)
cadf1ccf GX	605	return ret;
b17500a0	606
bb88e8da	607	it.it.buf = __EROFS_BUF_INITIALIZER;
b17500a0 GX	608	it.dentry = dentry;
	609	it.buffer = buffer;
	610	it.buffer_size = buffer_size;
	611	it.buffer_ofs = 0;
	612
	613	it.it.sb = dentry->d_sb;
	614
	615	ret = inline_listxattr(&it);
bb88e8da GX	616	if (ret >= 0 \|\| ret == -ENOATTR)
	617	ret = shared_listxattr(&it);
	618	erofs_put_metabuf(&it.it.buf);
	619	return ret;
b17500a0 GX	620	}
b17500a0 GX	621
516c115c	622	#ifdef CONFIG_EROFS_FS_POSIX_ACL
0cad6246	623	struct posix_acl erofs_get_acl(struct inode inode, int type, bool rcu)
516c115c GX	624	{
	625	struct posix_acl *acl;
	626	int prefix, rc;
	627	char *value = NULL;
	628
0cad6246 MS	629	if (rcu)
	630	return ERR_PTR(-ECHILD);
	631
516c115c GX	632	switch (type) {
	633	case ACL_TYPE_ACCESS:
	634	prefix = EROFS_XATTR_INDEX_POSIX_ACL_ACCESS;
	635	break;
	636	case ACL_TYPE_DEFAULT:
	637	prefix = EROFS_XATTR_INDEX_POSIX_ACL_DEFAULT;
	638	break;
	639	default:
	640	return ERR_PTR(-EINVAL);
	641	}
	642
	643	rc = erofs_getxattr(inode, prefix, "", NULL, 0);
	644	if (rc > 0) {
	645	value = kmalloc(rc, GFP_KERNEL);
	646	if (!value)
	647	return ERR_PTR(-ENOMEM);
	648	rc = erofs_getxattr(inode, prefix, "", value, rc);
	649	}
	650
	651	if (rc == -ENOATTR)
	652	acl = NULL;
	653	else if (rc < 0)
	654	acl = ERR_PTR(rc);
	655	else
	656	acl = posix_acl_from_xattr(&init_user_ns, value, rc);
	657	kfree(value);
	658	return acl;
	659	}
	660	#endif