[linux-2.6-block.git] / fs / jffs2 / acl.c

/*
 * JFFS2 -- Journalling Flash File System, Version 2.
 *
 * Copyright © 2006  NEC Corporation
 *
 * Created by KaiGai Kohei <kaigai@ak.jp.nec.com>
 *
 * For licensing information, see the file 'LICENCE' in this directory.
 *
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/sched.h>
#include <linux/time.h>
#include <linux/crc32.h>
#include <linux/jffs2.h>
#include <linux/xattr.h>
#include <linux/posix_acl_xattr.h>
#include <linux/mtd/mtd.h>
#include "nodelist.h"

static size_t jffs2_acl_size(int count)
{
	if (count <= 4) {
		return sizeof(struct jffs2_acl_header)
		       + count * sizeof(struct jffs2_acl_entry_short);
	} else {
		return sizeof(struct jffs2_acl_header)
		       + 4 * sizeof(struct jffs2_acl_entry_short)
		       + (count - 4) * sizeof(struct jffs2_acl_entry);
	}
}

static int jffs2_acl_count(size_t size)
{
	size_t s;

	size -= sizeof(struct jffs2_acl_header);
	s = size - 4 * sizeof(struct jffs2_acl_entry_short);
	if (s < 0) {
		if (size % sizeof(struct jffs2_acl_entry_short))
			return -1;
		return size / sizeof(struct jffs2_acl_entry_short);
	} else {
		if (s % sizeof(struct jffs2_acl_entry))
			return -1;
		return s / sizeof(struct jffs2_acl_entry) + 4;
	}
}

static struct posix_acl *jffs2_acl_from_medium(void *value, size_t size)
{
	void *end = value + size;
	struct jffs2_acl_header *header = value;
	struct jffs2_acl_entry *entry;
	struct posix_acl *acl;
	uint32_t ver;
	int i, count;

	if (!value)
		return NULL;
	if (size < sizeof(struct jffs2_acl_header))
		return ERR_PTR(-EINVAL);
	ver = je32_to_cpu(header->a_version);
	if (ver != JFFS2_ACL_VERSION) {
		JFFS2_WARNING("Invalid ACL version. (=%u)\n", ver);
		return ERR_PTR(-EINVAL);
	}

	value += sizeof(struct jffs2_acl_header);
	count = jffs2_acl_count(size);
	if (count < 0)
		return ERR_PTR(-EINVAL);
	if (count == 0)
		return NULL;

	acl = posix_acl_alloc(count, GFP_KERNEL);
	if (!acl)
		return ERR_PTR(-ENOMEM);

	for (i=0; i < count; i++) {
		entry = value;
		if (value + sizeof(struct jffs2_acl_entry_short) > end)
			goto fail;
		acl->a_entries[i].e_tag = je16_to_cpu(entry->e_tag);
		acl->a_entries[i].e_perm = je16_to_cpu(entry->e_perm);
		switch (acl->a_entries[i].e_tag) {
			case ACL_USER_OBJ:
			case ACL_GROUP_OBJ:
			case ACL_MASK:
			case ACL_OTHER:
				value += sizeof(struct jffs2_acl_entry_short);
				acl->a_entries[i].e_id = ACL_UNDEFINED_ID;
				break;

			case ACL_USER:
			case ACL_GROUP:
				value += sizeof(struct jffs2_acl_entry);
				if (value > end)
					goto fail;
				acl->a_entries[i].e_id = je32_to_cpu(entry->e_id);
				break;

			default:
				goto fail;
		}
	}
	if (value != end)
		goto fail;
	return acl;
 fail:
	posix_acl_release(acl);
	return ERR_PTR(-EINVAL);
}

static void *jffs2_acl_to_medium(const struct posix_acl *acl, size_t *size)
{
	struct jffs2_acl_header *header;
	struct jffs2_acl_entry *entry;
	void *e;
	size_t i;

	*size = jffs2_acl_size(acl->a_count);
	header = kmalloc(sizeof(*header) + acl->a_count * sizeof(*entry), GFP_KERNEL);
	if (!header)
		return ERR_PTR(-ENOMEM);
	header->a_version = cpu_to_je32(JFFS2_ACL_VERSION);
	e = header + 1;
	for (i=0; i < acl->a_count; i++) {
		entry = e;
		entry->e_tag = cpu_to_je16(acl->a_entries[i].e_tag);
		entry->e_perm = cpu_to_je16(acl->a_entries[i].e_perm);
		switch(acl->a_entries[i].e_tag) {
			case ACL_USER:
			case ACL_GROUP:
				entry->e_id = cpu_to_je32(acl->a_entries[i].e_id);
				e += sizeof(struct jffs2_acl_entry);
				break;

			case ACL_USER_OBJ:
			case ACL_GROUP_OBJ:
			case ACL_MASK:
			case ACL_OTHER:
				e += sizeof(struct jffs2_acl_entry_short);
				break;

			default:
				goto fail;
		}
	}
	return header;
 fail:
	kfree(header);
	return ERR_PTR(-EINVAL);
}

static struct posix_acl *jffs2_iget_acl(struct inode *inode, struct posix_acl **i_acl)
{
	struct posix_acl *acl = JFFS2_ACL_NOT_CACHED;

	spin_lock(&inode->i_lock);
	if (*i_acl != JFFS2_ACL_NOT_CACHED)
		acl = posix_acl_dup(*i_acl);
	spin_unlock(&inode->i_lock);
	return acl;
}

static void jffs2_iset_acl(struct inode *inode, struct posix_acl **i_acl, struct posix_acl *acl)
{
	spin_lock(&inode->i_lock);
	if (*i_acl != JFFS2_ACL_NOT_CACHED)
		posix_acl_release(*i_acl);
	*i_acl = posix_acl_dup(acl);
	spin_unlock(&inode->i_lock);
}

static struct posix_acl *jffs2_get_acl(struct inode *inode, int type)
{
	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
	struct posix_acl *acl;
	char *value = NULL;
	int rc, xprefix;

	switch (type) {
	case ACL_TYPE_ACCESS:
		acl = jffs2_iget_acl(inode, &f->i_acl_access);
		if (acl != JFFS2_ACL_NOT_CACHED)
			return acl;
		xprefix = JFFS2_XPREFIX_ACL_ACCESS;
		break;
	case ACL_TYPE_DEFAULT:
		acl = jffs2_iget_acl(inode, &f->i_acl_default);
		if (acl != JFFS2_ACL_NOT_CACHED)
			return acl;
		xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
		break;
	default:
		return ERR_PTR(-EINVAL);
	}
	rc = do_jffs2_getxattr(inode, xprefix, "", NULL, 0);
	if (rc > 0) {
		value = kmalloc(rc, GFP_KERNEL);
		if (!value)
			return ERR_PTR(-ENOMEM);
		rc = do_jffs2_getxattr(inode, xprefix, "", value, rc);
	}
	if (rc > 0) {
		acl = jffs2_acl_from_medium(value, rc);
	} else if (rc == -ENODATA || rc == -ENOSYS) {
		acl = NULL;
	} else {
		acl = ERR_PTR(rc);
	}
	if (value)
		kfree(value);
	if (!IS_ERR(acl)) {
		switch (type) {
		case ACL_TYPE_ACCESS:
			jffs2_iset_acl(inode, &f->i_acl_access, acl);
			break;
		case ACL_TYPE_DEFAULT:
			jffs2_iset_acl(inode, &f->i_acl_default, acl);
			break;
		}
	}
	return acl;
}

static int jffs2_set_acl(struct inode *inode, int type, struct posix_acl *acl)
{
	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
	size_t size = 0;
	char *value = NULL;
	int rc, xprefix;

	if (S_ISLNK(inode->i_mode))
		return -EOPNOTSUPP;

	switch (type) {
	case ACL_TYPE_ACCESS:
		xprefix = JFFS2_XPREFIX_ACL_ACCESS;
		if (acl) {
			mode_t mode = inode->i_mode;
			rc = posix_acl_equiv_mode(acl, &mode);
			if (rc < 0)
				return rc;
			if (inode->i_mode != mode) {
				inode->i_mode = mode;
				jffs2_dirty_inode(inode);
			}
			if (rc == 0)
				acl = NULL;
		}
		break;
	case ACL_TYPE_DEFAULT:
		xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
		if (!S_ISDIR(inode->i_mode))
			return acl ? -EACCES : 0;
		break;
	default:
		return -EINVAL;
	}
	if (acl) {
		value = jffs2_acl_to_medium(acl, &size);
		if (IS_ERR(value))
			return PTR_ERR(value);
	}

	rc = do_jffs2_setxattr(inode, xprefix, "", value, size, 0);
	if (!value && rc == -ENODATA)
		rc = 0;
	if (value)
		kfree(value);
	if (!rc) {
		switch(type) {
		case ACL_TYPE_ACCESS:
			jffs2_iset_acl(inode, &f->i_acl_access, acl);
			break;
		case ACL_TYPE_DEFAULT:
			jffs2_iset_acl(inode, &f->i_acl_default, acl);
			break;
		}
	}
	return rc;
}

static int jffs2_check_acl(struct inode *inode, int mask)
{
	struct posix_acl *acl;
	int rc;

	acl = jffs2_get_acl(inode, ACL_TYPE_ACCESS);
	if (IS_ERR(acl))
		return PTR_ERR(acl);
	if (acl) {
		rc = posix_acl_permission(inode, acl, mask);
		posix_acl_release(acl);
		return rc;
	}
	return -EAGAIN;
}

int jffs2_permission(struct inode *inode, int mask, struct nameidata *nd)
{
	return generic_permission(inode, mask, jffs2_check_acl);
}

int jffs2_init_acl(struct inode *inode, struct inode *dir)
{
	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
	struct posix_acl *acl = NULL, *clone;
	mode_t mode;
	int rc = 0;

	f->i_acl_access = JFFS2_ACL_NOT_CACHED;
	f->i_acl_default = JFFS2_ACL_NOT_CACHED;
	if (!S_ISLNK(inode->i_mode)) {
		acl = jffs2_get_acl(dir, ACL_TYPE_DEFAULT);
		if (IS_ERR(acl))
			return PTR_ERR(acl);
		if (!acl)
			inode->i_mode &= ~current->fs->umask;
	}
	if (acl) {
		if (S_ISDIR(inode->i_mode)) {
			rc = jffs2_set_acl(inode, ACL_TYPE_DEFAULT, acl);
			if (rc)
				goto cleanup;
		}
		clone = posix_acl_clone(acl, GFP_KERNEL);
		rc = -ENOMEM;
		if (!clone)
			goto cleanup;
		mode = inode->i_mode;
		rc = posix_acl_create_masq(clone, &mode);
		if (rc >= 0) {
			inode->i_mode = mode;
			if (rc > 0)
				rc = jffs2_set_acl(inode, ACL_TYPE_ACCESS, clone);
		}
		posix_acl_release(clone);
	}
 cleanup:
	posix_acl_release(acl);
	return rc;
}

void jffs2_clear_acl(struct jffs2_inode_info *f)
{
	if (f->i_acl_access && f->i_acl_access != JFFS2_ACL_NOT_CACHED) {
		posix_acl_release(f->i_acl_access);
		f->i_acl_access = JFFS2_ACL_NOT_CACHED;
	}
	if (f->i_acl_default && f->i_acl_default != JFFS2_ACL_NOT_CACHED) {
		posix_acl_release(f->i_acl_default);
		f->i_acl_default = JFFS2_ACL_NOT_CACHED;
	}
}

int jffs2_acl_chmod(struct inode *inode)
{
	struct posix_acl *acl, *clone;
	int rc;

	if (S_ISLNK(inode->i_mode))
		return -EOPNOTSUPP;
	acl = jffs2_get_acl(inode, ACL_TYPE_ACCESS);
	if (IS_ERR(acl) || !acl)
		return PTR_ERR(acl);
	clone = posix_acl_clone(acl, GFP_KERNEL);
	posix_acl_release(acl);
	if (!clone)
		return -ENOMEM;
	rc = posix_acl_chmod_masq(clone, inode->i_mode);
	if (!rc)
		rc = jffs2_set_acl(inode, ACL_TYPE_ACCESS, clone);
	posix_acl_release(clone);
	return rc;
}

static size_t jffs2_acl_access_listxattr(struct inode *inode, char *list, size_t list_size,
					 const char *name, size_t name_len)
{
	const int retlen = sizeof(POSIX_ACL_XATTR_ACCESS);

	if (list && retlen <= list_size)
		strcpy(list, POSIX_ACL_XATTR_ACCESS);
	return retlen;
}

static size_t jffs2_acl_default_listxattr(struct inode *inode, char *list, size_t list_size,
					  const char *name, size_t name_len)
{
	const int retlen = sizeof(POSIX_ACL_XATTR_DEFAULT);

	if (list && retlen <= list_size)
		strcpy(list, POSIX_ACL_XATTR_DEFAULT);
	return retlen;
}

static int jffs2_acl_getxattr(struct inode *inode, int type, void *buffer, size_t size)
{
	struct posix_acl *acl;
	int rc;

	acl = jffs2_get_acl(inode, type);
	if (IS_ERR(acl))
		return PTR_ERR(acl);
	if (!acl)
		return -ENODATA;
	rc = posix_acl_to_xattr(acl, buffer, size);
	posix_acl_release(acl);

	return rc;
}

static int jffs2_acl_access_getxattr(struct inode *inode, const char *name, void *buffer, size_t size)
{
	if (name[0] != '\0')
		return -EINVAL;
	return jffs2_acl_getxattr(inode, ACL_TYPE_ACCESS, buffer, size);
}

static int jffs2_acl_default_getxattr(struct inode *inode, const char *name, void *buffer, size_t size)
{
	if (name[0] != '\0')
		return -EINVAL;
	return jffs2_acl_getxattr(inode, ACL_TYPE_DEFAULT, buffer, size);
}

static int jffs2_acl_setxattr(struct inode *inode, int type, const void *value, size_t size)
{
	struct posix_acl *acl;
	int rc;

	if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
		return -EPERM;

	if (value) {
		acl = posix_acl_from_xattr(value, size);
		if (IS_ERR(acl))
			return PTR_ERR(acl);
		if (acl) {
			rc = posix_acl_valid(acl);
			if (rc)
				goto out;
		}
	} else {
		acl = NULL;
	}
	rc = jffs2_set_acl(inode, type, acl);
 out:
	posix_acl_release(acl);
	return rc;
}

static int jffs2_acl_access_setxattr(struct inode *inode, const char *name,
				     const void *buffer, size_t size, int flags)
{
	if (name[0] != '\0')
		return -EINVAL;
	return jffs2_acl_setxattr(inode, ACL_TYPE_ACCESS, buffer, size);
}

static int jffs2_acl_default_setxattr(struct inode *inode, const char *name,
				      const void *buffer, size_t size, int flags)
{
	if (name[0] != '\0')
		return -EINVAL;
	return jffs2_acl_setxattr(inode, ACL_TYPE_DEFAULT, buffer, size);
}

struct xattr_handler jffs2_acl_access_xattr_handler = {
	.prefix	= POSIX_ACL_XATTR_ACCESS,
	.list	= jffs2_acl_access_listxattr,
	.get	= jffs2_acl_access_getxattr,
	.set	= jffs2_acl_access_setxattr,
};

struct xattr_handler jffs2_acl_default_xattr_handler = {
	.prefix	= POSIX_ACL_XATTR_DEFAULT,
	.list	= jffs2_acl_default_listxattr,
	.get	= jffs2_acl_default_getxattr,
	.set	= jffs2_acl_default_setxattr,
};
Commit	Line	Data
652ecc20 KK	1	/*
652ecc20 KK	2	* JFFS2 -- Journalling Flash File System, Version 2.
aa98d7cf	3	*
c00c310e	4	* Copyright © 2006 NEC Corporation
aa98d7cf	5	*
652ecc20 KK	6	* Created by KaiGai Kohei <kaigai@ak.jp.nec.com>
	7	*
	8	* For licensing information, see the file 'LICENCE' in this directory.
	9	*
	10	*/
c00c310e	11
aa98d7cf KK	12	#include <linux/kernel.h>
	13	#include <linux/slab.h>
	14	#include <linux/fs.h>
914e2637	15	#include <linux/sched.h>
aa98d7cf KK	16	#include <linux/time.h>
	17	#include <linux/crc32.h>
	18	#include <linux/jffs2.h>
	19	#include <linux/xattr.h>
	20	#include <linux/posix_acl_xattr.h>
	21	#include <linux/mtd/mtd.h>
	22	#include "nodelist.h"
	23
	24	static size_t jffs2_acl_size(int count)
	25	{
	26	if (count <= 4) {
de1f72fa KK	27	return sizeof(struct jffs2_acl_header)
de1f72fa KK	28	+ count * sizeof(struct jffs2_acl_entry_short);
aa98d7cf	29	} else {
de1f72fa KK	30	return sizeof(struct jffs2_acl_header)
	31	+ 4 * sizeof(struct jffs2_acl_entry_short)
	32	+ (count - 4) * sizeof(struct jffs2_acl_entry);
aa98d7cf KK	33	}
	34	}
	35
	36	static int jffs2_acl_count(size_t size)
	37	{
	38	size_t s;
	39
de1f72fa KK	40	size -= sizeof(struct jffs2_acl_header);
de1f72fa KK	41	s = size - 4 * sizeof(struct jffs2_acl_entry_short);
aa98d7cf	42	if (s < 0) {
de1f72fa	43	if (size % sizeof(struct jffs2_acl_entry_short))
aa98d7cf	44	return -1;
de1f72fa	45	return size / sizeof(struct jffs2_acl_entry_short);
aa98d7cf	46	} else {
de1f72fa	47	if (s % sizeof(struct jffs2_acl_entry))
aa98d7cf	48	return -1;
de1f72fa	49	return s / sizeof(struct jffs2_acl_entry) + 4;
aa98d7cf KK	50	}
	51	}
	52
dea80134	53	static struct posix_acl jffs2_acl_from_medium(void value, size_t size)
aa98d7cf	54	{
dea80134 KK	55	void *end = value + size;
	56	struct jffs2_acl_header *header = value;
	57	struct jffs2_acl_entry *entry;
aa98d7cf KK	58	struct posix_acl *acl;
	59	uint32_t ver;
	60	int i, count;
	61
	62	if (!value)
	63	return NULL;
de1f72fa	64	if (size < sizeof(struct jffs2_acl_header))
aa98d7cf	65	return ERR_PTR(-EINVAL);
dea80134	66	ver = je32_to_cpu(header->a_version);
aa98d7cf KK	67	if (ver != JFFS2_ACL_VERSION) {
	68	JFFS2_WARNING("Invalid ACL version. (=%u)\n", ver);
	69	return ERR_PTR(-EINVAL);
	70	}
	71
dea80134	72	value += sizeof(struct jffs2_acl_header);
aa98d7cf KK	73	count = jffs2_acl_count(size);
	74	if (count < 0)
	75	return ERR_PTR(-EINVAL);
	76	if (count == 0)
	77	return NULL;
	78
	79	acl = posix_acl_alloc(count, GFP_KERNEL);
	80	if (!acl)
	81	return ERR_PTR(-ENOMEM);
	82
	83	for (i=0; i < count; i++) {
dea80134 KK	84	entry = value;
dea80134 KK	85	if (value + sizeof(struct jffs2_acl_entry_short) > end)
aa98d7cf KK	86	goto fail;
	87	acl->a_entries[i].e_tag = je16_to_cpu(entry->e_tag);
	88	acl->a_entries[i].e_perm = je16_to_cpu(entry->e_perm);
	89	switch (acl->a_entries[i].e_tag) {
	90	case ACL_USER_OBJ:
	91	case ACL_GROUP_OBJ:
	92	case ACL_MASK:
	93	case ACL_OTHER:
dea80134	94	value += sizeof(struct jffs2_acl_entry_short);
aa98d7cf KK	95	acl->a_entries[i].e_id = ACL_UNDEFINED_ID;
	96	break;
	97
	98	case ACL_USER:
	99	case ACL_GROUP:
dea80134 KK	100	value += sizeof(struct jffs2_acl_entry);
dea80134 KK	101	if (value > end)
aa98d7cf KK	102	goto fail;
	103	acl->a_entries[i].e_id = je32_to_cpu(entry->e_id);
	104	break;
	105
	106	default:
	107	goto fail;
	108	}
	109	}
	110	if (value != end)
	111	goto fail;
	112	return acl;
	113	fail:
	114	posix_acl_release(acl);
	115	return ERR_PTR(-EINVAL);
	116	}
	117
	118	static void jffs2_acl_to_medium(const struct posix_acl acl, size_t *size)
	119	{
dea80134 KK	120	struct jffs2_acl_header *header;
	121	struct jffs2_acl_entry *entry;
	122	void *e;
aa98d7cf KK	123	size_t i;
	124
	125	*size = jffs2_acl_size(acl->a_count);
dea80134 KK	126	header = kmalloc(sizeof(header) + acl->a_count sizeof(*entry), GFP_KERNEL);
dea80134 KK	127	if (!header)
aa98d7cf	128	return ERR_PTR(-ENOMEM);
dea80134 KK	129	header->a_version = cpu_to_je32(JFFS2_ACL_VERSION);
dea80134 KK	130	e = header + 1;
aa98d7cf	131	for (i=0; i < acl->a_count; i++) {
dea80134	132	entry = e;
aa98d7cf KK	133	entry->e_tag = cpu_to_je16(acl->a_entries[i].e_tag);
	134	entry->e_perm = cpu_to_je16(acl->a_entries[i].e_perm);
	135	switch(acl->a_entries[i].e_tag) {
	136	case ACL_USER:
	137	case ACL_GROUP:
	138	entry->e_id = cpu_to_je32(acl->a_entries[i].e_id);
de1f72fa	139	e += sizeof(struct jffs2_acl_entry);
aa98d7cf KK	140	break;
	141
	142	case ACL_USER_OBJ:
	143	case ACL_GROUP_OBJ:
	144	case ACL_MASK:
	145	case ACL_OTHER:
de1f72fa	146	e += sizeof(struct jffs2_acl_entry_short);
aa98d7cf KK	147	break;
	148
	149	default:
	150	goto fail;
	151	}
	152	}
dea80134	153	return header;
aa98d7cf	154	fail:
dea80134	155	kfree(header);
aa98d7cf KK	156	return ERR_PTR(-EINVAL);
	157	}
	158
	159	static struct posix_acl jffs2_iget_acl(struct inode inode, struct posix_acl **i_acl)
	160	{
	161	struct posix_acl *acl = JFFS2_ACL_NOT_CACHED;
	162
	163	spin_lock(&inode->i_lock);
	164	if (*i_acl != JFFS2_ACL_NOT_CACHED)
	165	acl = posix_acl_dup(*i_acl);
	166	spin_unlock(&inode->i_lock);
	167	return acl;
	168	}
	169
	170	static void jffs2_iset_acl(struct inode inode, struct posix_acl i_acl, struct posix_acl acl)
	171	{
	172	spin_lock(&inode->i_lock);
	173	if (*i_acl != JFFS2_ACL_NOT_CACHED)
	174	posix_acl_release(*i_acl);
	175	*i_acl = posix_acl_dup(acl);
	176	spin_unlock(&inode->i_lock);
	177	}
	178
	179	static struct posix_acl jffs2_get_acl(struct inode inode, int type)
	180	{
	181	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
	182	struct posix_acl *acl;
	183	char *value = NULL;
	184	int rc, xprefix;
	185
	186	switch (type) {
	187	case ACL_TYPE_ACCESS:
	188	acl = jffs2_iget_acl(inode, &f->i_acl_access);
	189	if (acl != JFFS2_ACL_NOT_CACHED)
	190	return acl;
	191	xprefix = JFFS2_XPREFIX_ACL_ACCESS;
	192	break;
	193	case ACL_TYPE_DEFAULT:
	194	acl = jffs2_iget_acl(inode, &f->i_acl_default);
	195	if (acl != JFFS2_ACL_NOT_CACHED)
	196	return acl;
	197	xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
	198	break;
	199	default:
	200	return ERR_PTR(-EINVAL);
	201	}
	202	rc = do_jffs2_getxattr(inode, xprefix, "", NULL, 0);
	203	if (rc > 0) {
	204	value = kmalloc(rc, GFP_KERNEL);
	205	if (!value)
	206	return ERR_PTR(-ENOMEM);
	207	rc = do_jffs2_getxattr(inode, xprefix, "", value, rc);
	208	}
	209	if (rc > 0) {
	210	acl = jffs2_acl_from_medium(value, rc);
	211	} else if (rc == -ENODATA \|\| rc == -ENOSYS) {
	212	acl = NULL;
	213	} else {
	214	acl = ERR_PTR(rc);
	215	}
	216	if (value)
	217	kfree(value);
	218	if (!IS_ERR(acl)) {
	219	switch (type) {
220	case ACL_TYPE_ACCESS:
221	jffs2_iset_acl(inode, &f->i_acl_access, acl);
222	break;
223	case ACL_TYPE_DEFAULT:
224	jffs2_iset_acl(inode, &f->i_acl_default, acl);
225	break;
226	}
227	}
228	return acl;
229	}
230
231	static int jffs2_set_acl(struct inode inode, int type, struct posix_acl acl)
232	{
233	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
234	size_t size = 0;
235	char *value = NULL;
236	int rc, xprefix;
237
238	if (S_ISLNK(inode->i_mode))
239	return -EOPNOTSUPP;
240
241	switch (type) {
242	case ACL_TYPE_ACCESS:
243	xprefix = JFFS2_XPREFIX_ACL_ACCESS;
244	if (acl) {
245	mode_t mode = inode->i_mode;
246	rc = posix_acl_equiv_mode(acl, &mode);
247	if (rc < 0)
248	return rc;
249	if (inode->i_mode != mode) {
250	inode->i_mode = mode;
251	jffs2_dirty_inode(inode);
252	}
253	if (rc == 0)
254	acl = NULL;
255	}
256	break;
257	case ACL_TYPE_DEFAULT:
258	xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
259	if (!S_ISDIR(inode->i_mode))
260	return acl ? -EACCES : 0;
261	break;
262	default:
263	return -EINVAL;
264	}
265	if (acl) {
266	value = jffs2_acl_to_medium(acl, &size);
267	if (IS_ERR(value))
268	return PTR_ERR(value);
269	}
270
271	rc = do_jffs2_setxattr(inode, xprefix, "", value, size, 0);
a1ae76e9 KK	272	if (!value && rc == -ENODATA)
a1ae76e9 KK	273	rc = 0;
aa98d7cf KK	274	if (value)
	275	kfree(value);
	276	if (!rc) {
	277	switch(type) {
	278	case ACL_TYPE_ACCESS:
	279	jffs2_iset_acl(inode, &f->i_acl_access, acl);
	280	break;
	281	case ACL_TYPE_DEFAULT:
	282	jffs2_iset_acl(inode, &f->i_acl_default, acl);
	283	break;
	284	}
	285	}
	286	return rc;
	287	}
	288
	289	static int jffs2_check_acl(struct inode *inode, int mask)
	290	{
	291	struct posix_acl *acl;
	292	int rc;
	293
	294	acl = jffs2_get_acl(inode, ACL_TYPE_ACCESS);
	295	if (IS_ERR(acl))
	296	return PTR_ERR(acl);
	297	if (acl) {
	298	rc = posix_acl_permission(inode, acl, mask);
	299	posix_acl_release(acl);
	300	return rc;
	301	}
	302	return -EAGAIN;
	303	}
	304
	305	int jffs2_permission(struct inode inode, int mask, struct nameidata nd)
	306	{
	307	return generic_permission(inode, mask, jffs2_check_acl);
	308	}
	309
	310	int jffs2_init_acl(struct inode inode, struct inode dir)
	311	{
	312	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
	313	struct posix_acl acl = NULL, clone;
	314	mode_t mode;
	315	int rc = 0;
	316
	317	f->i_acl_access = JFFS2_ACL_NOT_CACHED;
	318	f->i_acl_default = JFFS2_ACL_NOT_CACHED;
	319	if (!S_ISLNK(inode->i_mode)) {
	320	acl = jffs2_get_acl(dir, ACL_TYPE_DEFAULT);
	321	if (IS_ERR(acl))
	322	return PTR_ERR(acl);
	323	if (!acl)
	324	inode->i_mode &= ~current->fs->umask;
	325	}
	326	if (acl) {
	327	if (S_ISDIR(inode->i_mode)) {
	328	rc = jffs2_set_acl(inode, ACL_TYPE_DEFAULT, acl);
	329	if (rc)
	330	goto cleanup;
	331	}
	332	clone = posix_acl_clone(acl, GFP_KERNEL);
	333	rc = -ENOMEM;
	334	if (!clone)
	335	goto cleanup;
	336	mode = inode->i_mode;
	337	rc = posix_acl_create_masq(clone, &mode);
338	if (rc >= 0) {
339	inode->i_mode = mode;
340	if (rc > 0)
341	rc = jffs2_set_acl(inode, ACL_TYPE_ACCESS, clone);
342	}
343	posix_acl_release(clone);
344	}
345	cleanup:
346	posix_acl_release(acl);
347	return rc;
348	}
349
c7afb0f9	350	void jffs2_clear_acl(struct jffs2_inode_info *f)
aa98d7cf	351	{
aa98d7cf KK	352	if (f->i_acl_access && f->i_acl_access != JFFS2_ACL_NOT_CACHED) {
	353	posix_acl_release(f->i_acl_access);
	354	f->i_acl_access = JFFS2_ACL_NOT_CACHED;
	355	}
	356	if (f->i_acl_default && f->i_acl_default != JFFS2_ACL_NOT_CACHED) {
	357	posix_acl_release(f->i_acl_default);
	358	f->i_acl_default = JFFS2_ACL_NOT_CACHED;
	359	}
	360	}
	361
	362	int jffs2_acl_chmod(struct inode *inode)
	363	{
	364	struct posix_acl acl, clone;
	365	int rc;
	366
	367	if (S_ISLNK(inode->i_mode))
	368	return -EOPNOTSUPP;
	369	acl = jffs2_get_acl(inode, ACL_TYPE_ACCESS);
	370	if (IS_ERR(acl) \|\| !acl)
	371	return PTR_ERR(acl);
	372	clone = posix_acl_clone(acl, GFP_KERNEL);
	373	posix_acl_release(acl);
	374	if (!clone)
	375	return -ENOMEM;
	376	rc = posix_acl_chmod_masq(clone, inode->i_mode);
	377	if (!rc)
	378	rc = jffs2_set_acl(inode, ACL_TYPE_ACCESS, clone);
	379	posix_acl_release(clone);
	380	return rc;
	381	}
	382
	383	static size_t jffs2_acl_access_listxattr(struct inode inode, char list, size_t list_size,
	384	const char *name, size_t name_len)
	385	{
	386	const int retlen = sizeof(POSIX_ACL_XATTR_ACCESS);
	387
	388	if (list && retlen <= list_size)
	389	strcpy(list, POSIX_ACL_XATTR_ACCESS);
	390	return retlen;
	391	}
	392
	393	static size_t jffs2_acl_default_listxattr(struct inode inode, char list, size_t list_size,
	394	const char *name, size_t name_len)
	395	{
	396	const int retlen = sizeof(POSIX_ACL_XATTR_DEFAULT);
	397
	398	if (list && retlen <= list_size)
	399	strcpy(list, POSIX_ACL_XATTR_DEFAULT);
	400	return retlen;
	401	}
	402
	403	static int jffs2_acl_getxattr(struct inode inode, int type, void buffer, size_t size)
	404	{
	405	struct posix_acl *acl;
	406	int rc;
	407
	408	acl = jffs2_get_acl(inode, type);
	409	if (IS_ERR(acl))
	410	return PTR_ERR(acl);
	411	if (!acl)
	412	return -ENODATA;
	413	rc = posix_acl_to_xattr(acl, buffer, size);
	414	posix_acl_release(acl);
	415
416	return rc;
417	}
418
419	static int jffs2_acl_access_getxattr(struct inode inode, const char name, void *buffer, size_t size)
420	{
421	if (name[0] != '\0')
422	return -EINVAL;
423	return jffs2_acl_getxattr(inode, ACL_TYPE_ACCESS, buffer, size);
424	}
425
426	static int jffs2_acl_default_getxattr(struct inode inode, const char name, void *buffer, size_t size)
427	{
428	if (name[0] != '\0')
429	return -EINVAL;
430	return jffs2_acl_getxattr(inode, ACL_TYPE_DEFAULT, buffer, size);
431	}
432
433	static int jffs2_acl_setxattr(struct inode inode, int type, const void value, size_t size)
434	{
435	struct posix_acl *acl;
436	int rc;
437
438	if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
439	return -EPERM;
440
441	if (value) {
442	acl = posix_acl_from_xattr(value, size);
443	if (IS_ERR(acl))
444	return PTR_ERR(acl);
445	if (acl) {
446	rc = posix_acl_valid(acl);
447	if (rc)
448	goto out;
449	}
450	} else {
451	acl = NULL;
452	}
453	rc = jffs2_set_acl(inode, type, acl);
454	out:
455	posix_acl_release(acl);
456	return rc;
457	}
458
459	static int jffs2_acl_access_setxattr(struct inode inode, const char name,
460	const void *buffer, size_t size, int flags)
461	{
462	if (name[0] != '\0')
463	return -EINVAL;
464	return jffs2_acl_setxattr(inode, ACL_TYPE_ACCESS, buffer, size);
465	}
466
467	static int jffs2_acl_default_setxattr(struct inode inode, const char name,
468	const void *buffer, size_t size, int flags)
469	{
470	if (name[0] != '\0')
471	return -EINVAL;
472	return jffs2_acl_setxattr(inode, ACL_TYPE_DEFAULT, buffer, size);
473	}
474
475	struct xattr_handler jffs2_acl_access_xattr_handler = {
476	.prefix = POSIX_ACL_XATTR_ACCESS,
477	.list = jffs2_acl_access_listxattr,
478	.get = jffs2_acl_access_getxattr,
479	.set = jffs2_acl_access_setxattr,
480	};
481
482	struct xattr_handler jffs2_acl_default_xattr_handler = {
483	.prefix = POSIX_ACL_XATTR_DEFAULT,
484	.list = jffs2_acl_default_listxattr,
485	.get = jffs2_acl_default_getxattr,
486	.set = jffs2_acl_default_setxattr,
487	};