 bf3d846b78
			
		
	
	
	bf3d846b78
	
	
	
		
			
			Pull vfs updates from Al Viro: "Assorted stuff; the biggest pile here is Christoph's ACL series. Plus assorted cleanups and fixes all over the place... There will be another pile later this week" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (43 commits) __dentry_path() fixes vfs: Remove second variable named error in __dentry_path vfs: Is mounted should be testing mnt_ns for NULL or error. Fix race when checking i_size on direct i/o read hfsplus: remove can_set_xattr nfsd: use get_acl and ->set_acl fs: remove generic_acl nfs: use generic posix ACL infrastructure for v3 Posix ACLs gfs2: use generic posix ACL infrastructure jfs: use generic posix ACL infrastructure xfs: use generic posix ACL infrastructure reiserfs: use generic posix ACL infrastructure ocfs2: use generic posix ACL infrastructure jffs2: use generic posix ACL infrastructure hfsplus: use generic posix ACL infrastructure f2fs: use generic posix ACL infrastructure ext2/3/4: use generic posix ACL infrastructure btrfs: use generic posix ACL infrastructure fs: make posix_acl_create more useful fs: make posix_acl_chmod more useful ...
		
			
				
	
	
		
			888 lines
		
	
	
	
		
			20 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			888 lines
		
	
	
	
		
			20 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
 | |
|  * Copyright (C) 2002,2003 by Andreas Gruenbacher <a.gruenbacher@computer.org>
 | |
|  *
 | |
|  * Fixes from William Schumacher incorporated on 15 March 2001.
 | |
|  *    (Reported by Charles Bertsch, <CBertsch@microtest.com>).
 | |
|  */
 | |
| 
 | |
| /*
 | |
|  *  This file contains generic functions for manipulating
 | |
|  *  POSIX 1003.1e draft standard 17 ACLs.
 | |
|  */
 | |
| 
 | |
| #include <linux/kernel.h>
 | |
| #include <linux/slab.h>
 | |
| #include <linux/atomic.h>
 | |
| #include <linux/fs.h>
 | |
| #include <linux/sched.h>
 | |
| #include <linux/posix_acl.h>
 | |
| #include <linux/posix_acl_xattr.h>
 | |
| #include <linux/xattr.h>
 | |
| #include <linux/export.h>
 | |
| #include <linux/user_namespace.h>
 | |
| 
 | |
| struct posix_acl **acl_by_type(struct inode *inode, int type)
 | |
| {
 | |
| 	switch (type) {
 | |
| 	case ACL_TYPE_ACCESS:
 | |
| 		return &inode->i_acl;
 | |
| 	case ACL_TYPE_DEFAULT:
 | |
| 		return &inode->i_default_acl;
 | |
| 	default:
 | |
| 		BUG();
 | |
| 	}
 | |
| }
 | |
| EXPORT_SYMBOL(acl_by_type);
 | |
| 
 | |
| struct posix_acl *get_cached_acl(struct inode *inode, int type)
 | |
| {
 | |
| 	struct posix_acl **p = acl_by_type(inode, type);
 | |
| 	struct posix_acl *acl = ACCESS_ONCE(*p);
 | |
| 	if (acl) {
 | |
| 		spin_lock(&inode->i_lock);
 | |
| 		acl = *p;
 | |
| 		if (acl != ACL_NOT_CACHED)
 | |
| 			acl = posix_acl_dup(acl);
 | |
| 		spin_unlock(&inode->i_lock);
 | |
| 	}
 | |
| 	return acl;
 | |
| }
 | |
| EXPORT_SYMBOL(get_cached_acl);
 | |
| 
 | |
| struct posix_acl *get_cached_acl_rcu(struct inode *inode, int type)
 | |
| {
 | |
| 	return rcu_dereference(*acl_by_type(inode, type));
 | |
| }
 | |
| EXPORT_SYMBOL(get_cached_acl_rcu);
 | |
| 
 | |
| void set_cached_acl(struct inode *inode, int type, struct posix_acl *acl)
 | |
| {
 | |
| 	struct posix_acl **p = acl_by_type(inode, type);
 | |
| 	struct posix_acl *old;
 | |
| 	spin_lock(&inode->i_lock);
 | |
| 	old = *p;
 | |
| 	rcu_assign_pointer(*p, posix_acl_dup(acl));
 | |
| 	spin_unlock(&inode->i_lock);
 | |
| 	if (old != ACL_NOT_CACHED)
 | |
| 		posix_acl_release(old);
 | |
| }
 | |
| EXPORT_SYMBOL(set_cached_acl);
 | |
| 
 | |
| void forget_cached_acl(struct inode *inode, int type)
 | |
| {
 | |
| 	struct posix_acl **p = acl_by_type(inode, type);
 | |
| 	struct posix_acl *old;
 | |
| 	spin_lock(&inode->i_lock);
 | |
| 	old = *p;
 | |
| 	*p = ACL_NOT_CACHED;
 | |
| 	spin_unlock(&inode->i_lock);
 | |
| 	if (old != ACL_NOT_CACHED)
 | |
| 		posix_acl_release(old);
 | |
| }
 | |
| EXPORT_SYMBOL(forget_cached_acl);
 | |
| 
 | |
| void forget_all_cached_acls(struct inode *inode)
 | |
| {
 | |
| 	struct posix_acl *old_access, *old_default;
 | |
| 	spin_lock(&inode->i_lock);
 | |
| 	old_access = inode->i_acl;
 | |
| 	old_default = inode->i_default_acl;
 | |
| 	inode->i_acl = inode->i_default_acl = ACL_NOT_CACHED;
 | |
| 	spin_unlock(&inode->i_lock);
 | |
| 	if (old_access != ACL_NOT_CACHED)
 | |
| 		posix_acl_release(old_access);
 | |
| 	if (old_default != ACL_NOT_CACHED)
 | |
| 		posix_acl_release(old_default);
 | |
| }
 | |
| EXPORT_SYMBOL(forget_all_cached_acls);
 | |
| 
 | |
| struct posix_acl *get_acl(struct inode *inode, int type)
 | |
| {
 | |
| 	struct posix_acl *acl;
 | |
| 
 | |
| 	acl = get_cached_acl(inode, type);
 | |
| 	if (acl != ACL_NOT_CACHED)
 | |
| 		return acl;
 | |
| 
 | |
| 	if (!IS_POSIXACL(inode))
 | |
| 		return NULL;
 | |
| 
 | |
| 	/*
 | |
| 	 * A filesystem can force a ACL callback by just never filling the
 | |
| 	 * ACL cache. But normally you'd fill the cache either at inode
 | |
| 	 * instantiation time, or on the first ->get_acl call.
 | |
| 	 *
 | |
| 	 * If the filesystem doesn't have a get_acl() function at all, we'll
 | |
| 	 * just create the negative cache entry.
 | |
| 	 */
 | |
| 	if (!inode->i_op->get_acl) {
 | |
| 		set_cached_acl(inode, type, NULL);
 | |
| 		return NULL;
 | |
| 	}
 | |
| 	return inode->i_op->get_acl(inode, type);
 | |
| }
 | |
| EXPORT_SYMBOL(get_acl);
 | |
| 
 | |
| /*
 | |
|  * Init a fresh posix_acl
 | |
|  */
 | |
| void
 | |
| posix_acl_init(struct posix_acl *acl, int count)
 | |
| {
 | |
| 	atomic_set(&acl->a_refcount, 1);
 | |
| 	acl->a_count = count;
 | |
| }
 | |
| EXPORT_SYMBOL(posix_acl_init);
 | |
| 
 | |
| /*
 | |
|  * Allocate a new ACL with the specified number of entries.
 | |
|  */
 | |
| struct posix_acl *
 | |
| posix_acl_alloc(int count, gfp_t flags)
 | |
| {
 | |
| 	const size_t size = sizeof(struct posix_acl) +
 | |
| 	                    count * sizeof(struct posix_acl_entry);
 | |
| 	struct posix_acl *acl = kmalloc(size, flags);
 | |
| 	if (acl)
 | |
| 		posix_acl_init(acl, count);
 | |
| 	return acl;
 | |
| }
 | |
| EXPORT_SYMBOL(posix_acl_alloc);
 | |
| 
 | |
| /*
 | |
|  * Clone an ACL.
 | |
|  */
 | |
| static struct posix_acl *
 | |
| posix_acl_clone(const struct posix_acl *acl, gfp_t flags)
 | |
| {
 | |
| 	struct posix_acl *clone = NULL;
 | |
| 
 | |
| 	if (acl) {
 | |
| 		int size = sizeof(struct posix_acl) + acl->a_count *
 | |
| 		           sizeof(struct posix_acl_entry);
 | |
| 		clone = kmemdup(acl, size, flags);
 | |
| 		if (clone)
 | |
| 			atomic_set(&clone->a_refcount, 1);
 | |
| 	}
 | |
| 	return clone;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Check if an acl is valid. Returns 0 if it is, or -E... otherwise.
 | |
|  */
 | |
| int
 | |
| posix_acl_valid(const struct posix_acl *acl)
 | |
| {
 | |
| 	const struct posix_acl_entry *pa, *pe;
 | |
| 	int state = ACL_USER_OBJ;
 | |
| 	int needs_mask = 0;
 | |
| 
 | |
| 	FOREACH_ACL_ENTRY(pa, acl, pe) {
 | |
| 		if (pa->e_perm & ~(ACL_READ|ACL_WRITE|ACL_EXECUTE))
 | |
| 			return -EINVAL;
 | |
| 		switch (pa->e_tag) {
 | |
| 			case ACL_USER_OBJ:
 | |
| 				if (state == ACL_USER_OBJ) {
 | |
| 					state = ACL_USER;
 | |
| 					break;
 | |
| 				}
 | |
| 				return -EINVAL;
 | |
| 
 | |
| 			case ACL_USER:
 | |
| 				if (state != ACL_USER)
 | |
| 					return -EINVAL;
 | |
| 				if (!uid_valid(pa->e_uid))
 | |
| 					return -EINVAL;
 | |
| 				needs_mask = 1;
 | |
| 				break;
 | |
| 
 | |
| 			case ACL_GROUP_OBJ:
 | |
| 				if (state == ACL_USER) {
 | |
| 					state = ACL_GROUP;
 | |
| 					break;
 | |
| 				}
 | |
| 				return -EINVAL;
 | |
| 
 | |
| 			case ACL_GROUP:
 | |
| 				if (state != ACL_GROUP)
 | |
| 					return -EINVAL;
 | |
| 				if (!gid_valid(pa->e_gid))
 | |
| 					return -EINVAL;
 | |
| 				needs_mask = 1;
 | |
| 				break;
 | |
| 
 | |
| 			case ACL_MASK:
 | |
| 				if (state != ACL_GROUP)
 | |
| 					return -EINVAL;
 | |
| 				state = ACL_OTHER;
 | |
| 				break;
 | |
| 
 | |
| 			case ACL_OTHER:
 | |
| 				if (state == ACL_OTHER ||
 | |
| 				    (state == ACL_GROUP && !needs_mask)) {
 | |
| 					state = 0;
 | |
| 					break;
 | |
| 				}
 | |
| 				return -EINVAL;
 | |
| 
 | |
| 			default:
 | |
| 				return -EINVAL;
 | |
| 		}
 | |
| 	}
 | |
| 	if (state == 0)
 | |
| 		return 0;
 | |
| 	return -EINVAL;
 | |
| }
 | |
| EXPORT_SYMBOL(posix_acl_valid);
 | |
| 
 | |
| /*
 | |
|  * Returns 0 if the acl can be exactly represented in the traditional
 | |
|  * file mode permission bits, or else 1. Returns -E... on error.
 | |
|  */
 | |
| int
 | |
| posix_acl_equiv_mode(const struct posix_acl *acl, umode_t *mode_p)
 | |
| {
 | |
| 	const struct posix_acl_entry *pa, *pe;
 | |
| 	umode_t mode = 0;
 | |
| 	int not_equiv = 0;
 | |
| 
 | |
| 	FOREACH_ACL_ENTRY(pa, acl, pe) {
 | |
| 		switch (pa->e_tag) {
 | |
| 			case ACL_USER_OBJ:
 | |
| 				mode |= (pa->e_perm & S_IRWXO) << 6;
 | |
| 				break;
 | |
| 			case ACL_GROUP_OBJ:
 | |
| 				mode |= (pa->e_perm & S_IRWXO) << 3;
 | |
| 				break;
 | |
| 			case ACL_OTHER:
 | |
| 				mode |= pa->e_perm & S_IRWXO;
 | |
| 				break;
 | |
| 			case ACL_MASK:
 | |
| 				mode = (mode & ~S_IRWXG) |
 | |
| 				       ((pa->e_perm & S_IRWXO) << 3);
 | |
| 				not_equiv = 1;
 | |
| 				break;
 | |
| 			case ACL_USER:
 | |
| 			case ACL_GROUP:
 | |
| 				not_equiv = 1;
 | |
| 				break;
 | |
| 			default:
 | |
| 				return -EINVAL;
 | |
| 		}
 | |
| 	}
 | |
|         if (mode_p)
 | |
|                 *mode_p = (*mode_p & ~S_IRWXUGO) | mode;
 | |
|         return not_equiv;
 | |
| }
 | |
| EXPORT_SYMBOL(posix_acl_equiv_mode);
 | |
| 
 | |
| /*
 | |
|  * Create an ACL representing the file mode permission bits of an inode.
 | |
|  */
 | |
| struct posix_acl *
 | |
| posix_acl_from_mode(umode_t mode, gfp_t flags)
 | |
| {
 | |
| 	struct posix_acl *acl = posix_acl_alloc(3, flags);
 | |
| 	if (!acl)
 | |
| 		return ERR_PTR(-ENOMEM);
 | |
| 
 | |
| 	acl->a_entries[0].e_tag  = ACL_USER_OBJ;
 | |
| 	acl->a_entries[0].e_perm = (mode & S_IRWXU) >> 6;
 | |
| 
 | |
| 	acl->a_entries[1].e_tag  = ACL_GROUP_OBJ;
 | |
| 	acl->a_entries[1].e_perm = (mode & S_IRWXG) >> 3;
 | |
| 
 | |
| 	acl->a_entries[2].e_tag  = ACL_OTHER;
 | |
| 	acl->a_entries[2].e_perm = (mode & S_IRWXO);
 | |
| 	return acl;
 | |
| }
 | |
| EXPORT_SYMBOL(posix_acl_from_mode);
 | |
| 
 | |
| /*
 | |
|  * Return 0 if current is granted want access to the inode
 | |
|  * by the acl. Returns -E... otherwise.
 | |
|  */
 | |
| int
 | |
| posix_acl_permission(struct inode *inode, const struct posix_acl *acl, int want)
 | |
| {
 | |
| 	const struct posix_acl_entry *pa, *pe, *mask_obj;
 | |
| 	int found = 0;
 | |
| 
 | |
| 	want &= MAY_READ | MAY_WRITE | MAY_EXEC | MAY_NOT_BLOCK;
 | |
| 
 | |
| 	FOREACH_ACL_ENTRY(pa, acl, pe) {
 | |
|                 switch(pa->e_tag) {
 | |
|                         case ACL_USER_OBJ:
 | |
| 				/* (May have been checked already) */
 | |
| 				if (uid_eq(inode->i_uid, current_fsuid()))
 | |
|                                         goto check_perm;
 | |
|                                 break;
 | |
|                         case ACL_USER:
 | |
| 				if (uid_eq(pa->e_uid, current_fsuid()))
 | |
|                                         goto mask;
 | |
| 				break;
 | |
|                         case ACL_GROUP_OBJ:
 | |
|                                 if (in_group_p(inode->i_gid)) {
 | |
| 					found = 1;
 | |
| 					if ((pa->e_perm & want) == want)
 | |
| 						goto mask;
 | |
|                                 }
 | |
| 				break;
 | |
|                         case ACL_GROUP:
 | |
| 				if (in_group_p(pa->e_gid)) {
 | |
| 					found = 1;
 | |
| 					if ((pa->e_perm & want) == want)
 | |
| 						goto mask;
 | |
|                                 }
 | |
|                                 break;
 | |
|                         case ACL_MASK:
 | |
|                                 break;
 | |
|                         case ACL_OTHER:
 | |
| 				if (found)
 | |
| 					return -EACCES;
 | |
| 				else
 | |
| 					goto check_perm;
 | |
| 			default:
 | |
| 				return -EIO;
 | |
|                 }
 | |
|         }
 | |
| 	return -EIO;
 | |
| 
 | |
| mask:
 | |
| 	for (mask_obj = pa+1; mask_obj != pe; mask_obj++) {
 | |
| 		if (mask_obj->e_tag == ACL_MASK) {
 | |
| 			if ((pa->e_perm & mask_obj->e_perm & want) == want)
 | |
| 				return 0;
 | |
| 			return -EACCES;
 | |
| 		}
 | |
| 	}
 | |
| 
 | |
| check_perm:
 | |
| 	if ((pa->e_perm & want) == want)
 | |
| 		return 0;
 | |
| 	return -EACCES;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Modify acl when creating a new inode. The caller must ensure the acl is
 | |
|  * only referenced once.
 | |
|  *
 | |
|  * mode_p initially must contain the mode parameter to the open() / creat()
 | |
|  * system calls. All permissions that are not granted by the acl are removed.
 | |
|  * The permissions in the acl are changed to reflect the mode_p parameter.
 | |
|  */
 | |
| static int posix_acl_create_masq(struct posix_acl *acl, umode_t *mode_p)
 | |
| {
 | |
| 	struct posix_acl_entry *pa, *pe;
 | |
| 	struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL;
 | |
| 	umode_t mode = *mode_p;
 | |
| 	int not_equiv = 0;
 | |
| 
 | |
| 	/* assert(atomic_read(acl->a_refcount) == 1); */
 | |
| 
 | |
| 	FOREACH_ACL_ENTRY(pa, acl, pe) {
 | |
|                 switch(pa->e_tag) {
 | |
|                         case ACL_USER_OBJ:
 | |
| 				pa->e_perm &= (mode >> 6) | ~S_IRWXO;
 | |
| 				mode &= (pa->e_perm << 6) | ~S_IRWXU;
 | |
| 				break;
 | |
| 
 | |
| 			case ACL_USER:
 | |
| 			case ACL_GROUP:
 | |
| 				not_equiv = 1;
 | |
| 				break;
 | |
| 
 | |
|                         case ACL_GROUP_OBJ:
 | |
| 				group_obj = pa;
 | |
|                                 break;
 | |
| 
 | |
|                         case ACL_OTHER:
 | |
| 				pa->e_perm &= mode | ~S_IRWXO;
 | |
| 				mode &= pa->e_perm | ~S_IRWXO;
 | |
|                                 break;
 | |
| 
 | |
|                         case ACL_MASK:
 | |
| 				mask_obj = pa;
 | |
| 				not_equiv = 1;
 | |
|                                 break;
 | |
| 
 | |
| 			default:
 | |
| 				return -EIO;
 | |
|                 }
 | |
|         }
 | |
| 
 | |
| 	if (mask_obj) {
 | |
| 		mask_obj->e_perm &= (mode >> 3) | ~S_IRWXO;
 | |
| 		mode &= (mask_obj->e_perm << 3) | ~S_IRWXG;
 | |
| 	} else {
 | |
| 		if (!group_obj)
 | |
| 			return -EIO;
 | |
| 		group_obj->e_perm &= (mode >> 3) | ~S_IRWXO;
 | |
| 		mode &= (group_obj->e_perm << 3) | ~S_IRWXG;
 | |
| 	}
 | |
| 
 | |
| 	*mode_p = (*mode_p & ~S_IRWXUGO) | mode;
 | |
|         return not_equiv;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Modify the ACL for the chmod syscall.
 | |
|  */
 | |
| static int __posix_acl_chmod_masq(struct posix_acl *acl, umode_t mode)
 | |
| {
 | |
| 	struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL;
 | |
| 	struct posix_acl_entry *pa, *pe;
 | |
| 
 | |
| 	/* assert(atomic_read(acl->a_refcount) == 1); */
 | |
| 
 | |
| 	FOREACH_ACL_ENTRY(pa, acl, pe) {
 | |
| 		switch(pa->e_tag) {
 | |
| 			case ACL_USER_OBJ:
 | |
| 				pa->e_perm = (mode & S_IRWXU) >> 6;
 | |
| 				break;
 | |
| 
 | |
| 			case ACL_USER:
 | |
| 			case ACL_GROUP:
 | |
| 				break;
 | |
| 
 | |
| 			case ACL_GROUP_OBJ:
 | |
| 				group_obj = pa;
 | |
| 				break;
 | |
| 
 | |
| 			case ACL_MASK:
 | |
| 				mask_obj = pa;
 | |
| 				break;
 | |
| 
 | |
| 			case ACL_OTHER:
 | |
| 				pa->e_perm = (mode & S_IRWXO);
 | |
| 				break;
 | |
| 
 | |
| 			default:
 | |
| 				return -EIO;
 | |
| 		}
 | |
| 	}
 | |
| 
 | |
| 	if (mask_obj) {
 | |
| 		mask_obj->e_perm = (mode & S_IRWXG) >> 3;
 | |
| 	} else {
 | |
| 		if (!group_obj)
 | |
| 			return -EIO;
 | |
| 		group_obj->e_perm = (mode & S_IRWXG) >> 3;
 | |
| 	}
 | |
| 
 | |
| 	return 0;
 | |
| }
 | |
| 
 | |
| int
 | |
| __posix_acl_create(struct posix_acl **acl, gfp_t gfp, umode_t *mode_p)
 | |
| {
 | |
| 	struct posix_acl *clone = posix_acl_clone(*acl, gfp);
 | |
| 	int err = -ENOMEM;
 | |
| 	if (clone) {
 | |
| 		err = posix_acl_create_masq(clone, mode_p);
 | |
| 		if (err < 0) {
 | |
| 			posix_acl_release(clone);
 | |
| 			clone = NULL;
 | |
| 		}
 | |
| 	}
 | |
| 	posix_acl_release(*acl);
 | |
| 	*acl = clone;
 | |
| 	return err;
 | |
| }
 | |
| EXPORT_SYMBOL(__posix_acl_create);
 | |
| 
 | |
| int
 | |
| __posix_acl_chmod(struct posix_acl **acl, gfp_t gfp, umode_t mode)
 | |
| {
 | |
| 	struct posix_acl *clone = posix_acl_clone(*acl, gfp);
 | |
| 	int err = -ENOMEM;
 | |
| 	if (clone) {
 | |
| 		err = __posix_acl_chmod_masq(clone, mode);
 | |
| 		if (err) {
 | |
| 			posix_acl_release(clone);
 | |
| 			clone = NULL;
 | |
| 		}
 | |
| 	}
 | |
| 	posix_acl_release(*acl);
 | |
| 	*acl = clone;
 | |
| 	return err;
 | |
| }
 | |
| EXPORT_SYMBOL(__posix_acl_chmod);
 | |
| 
 | |
| int
 | |
| posix_acl_chmod(struct inode *inode, umode_t mode)
 | |
| {
 | |
| 	struct posix_acl *acl;
 | |
| 	int ret = 0;
 | |
| 
 | |
| 	if (!IS_POSIXACL(inode))
 | |
| 		return 0;
 | |
| 	if (!inode->i_op->set_acl)
 | |
| 		return -EOPNOTSUPP;
 | |
| 
 | |
| 	acl = get_acl(inode, ACL_TYPE_ACCESS);
 | |
| 	if (IS_ERR_OR_NULL(acl))
 | |
| 		return PTR_ERR(acl);
 | |
| 
 | |
| 	ret = __posix_acl_chmod(&acl, GFP_KERNEL, mode);
 | |
| 	if (ret)
 | |
| 		return ret;
 | |
| 	ret = inode->i_op->set_acl(inode, acl, ACL_TYPE_ACCESS);
 | |
| 	posix_acl_release(acl);
 | |
| 	return ret;
 | |
| }
 | |
| EXPORT_SYMBOL(posix_acl_chmod);
 | |
| 
 | |
| int
 | |
| posix_acl_create(struct inode *dir, umode_t *mode,
 | |
| 		struct posix_acl **default_acl, struct posix_acl **acl)
 | |
| {
 | |
| 	struct posix_acl *p;
 | |
| 	int ret;
 | |
| 
 | |
| 	if (S_ISLNK(*mode) || !IS_POSIXACL(dir))
 | |
| 		goto no_acl;
 | |
| 
 | |
| 	p = get_acl(dir, ACL_TYPE_DEFAULT);
 | |
| 	if (IS_ERR(p))
 | |
| 		return PTR_ERR(p);
 | |
| 
 | |
| 	if (!p) {
 | |
| 		*mode &= ~current_umask();
 | |
| 		goto no_acl;
 | |
| 	}
 | |
| 
 | |
| 	*acl = posix_acl_clone(p, GFP_NOFS);
 | |
| 	if (!*acl)
 | |
| 		return -ENOMEM;
 | |
| 
 | |
| 	ret = posix_acl_create_masq(*acl, mode);
 | |
| 	if (ret < 0) {
 | |
| 		posix_acl_release(*acl);
 | |
| 		return -ENOMEM;
 | |
| 	}
 | |
| 
 | |
| 	if (ret == 0) {
 | |
| 		posix_acl_release(*acl);
 | |
| 		*acl = NULL;
 | |
| 	}
 | |
| 
 | |
| 	if (!S_ISDIR(*mode)) {
 | |
| 		posix_acl_release(p);
 | |
| 		*default_acl = NULL;
 | |
| 	} else {
 | |
| 		*default_acl = p;
 | |
| 	}
 | |
| 	return 0;
 | |
| 
 | |
| no_acl:
 | |
| 	*default_acl = NULL;
 | |
| 	*acl = NULL;
 | |
| 	return 0;
 | |
| }
 | |
| EXPORT_SYMBOL_GPL(posix_acl_create);
 | |
| 
 | |
| /*
 | |
|  * Fix up the uids and gids in posix acl extended attributes in place.
 | |
|  */
 | |
| static void posix_acl_fix_xattr_userns(
 | |
| 	struct user_namespace *to, struct user_namespace *from,
 | |
| 	void *value, size_t size)
 | |
| {
 | |
| 	posix_acl_xattr_header *header = (posix_acl_xattr_header *)value;
 | |
| 	posix_acl_xattr_entry *entry = (posix_acl_xattr_entry *)(header+1), *end;
 | |
| 	int count;
 | |
| 	kuid_t uid;
 | |
| 	kgid_t gid;
 | |
| 
 | |
| 	if (!value)
 | |
| 		return;
 | |
| 	if (size < sizeof(posix_acl_xattr_header))
 | |
| 		return;
 | |
| 	if (header->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION))
 | |
| 		return;
 | |
| 
 | |
| 	count = posix_acl_xattr_count(size);
 | |
| 	if (count < 0)
 | |
| 		return;
 | |
| 	if (count == 0)
 | |
| 		return;
 | |
| 
 | |
| 	for (end = entry + count; entry != end; entry++) {
 | |
| 		switch(le16_to_cpu(entry->e_tag)) {
 | |
| 		case ACL_USER:
 | |
| 			uid = make_kuid(from, le32_to_cpu(entry->e_id));
 | |
| 			entry->e_id = cpu_to_le32(from_kuid(to, uid));
 | |
| 			break;
 | |
| 		case ACL_GROUP:
 | |
| 			gid = make_kgid(from, le32_to_cpu(entry->e_id));
 | |
| 			entry->e_id = cpu_to_le32(from_kgid(to, gid));
 | |
| 			break;
 | |
| 		default:
 | |
| 			break;
 | |
| 		}
 | |
| 	}
 | |
| }
 | |
| 
 | |
| void posix_acl_fix_xattr_from_user(void *value, size_t size)
 | |
| {
 | |
| 	struct user_namespace *user_ns = current_user_ns();
 | |
| 	if (user_ns == &init_user_ns)
 | |
| 		return;
 | |
| 	posix_acl_fix_xattr_userns(&init_user_ns, user_ns, value, size);
 | |
| }
 | |
| 
 | |
| void posix_acl_fix_xattr_to_user(void *value, size_t size)
 | |
| {
 | |
| 	struct user_namespace *user_ns = current_user_ns();
 | |
| 	if (user_ns == &init_user_ns)
 | |
| 		return;
 | |
| 	posix_acl_fix_xattr_userns(user_ns, &init_user_ns, value, size);
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Convert from extended attribute to in-memory representation.
 | |
|  */
 | |
| struct posix_acl *
 | |
| posix_acl_from_xattr(struct user_namespace *user_ns,
 | |
| 		     const void *value, size_t size)
 | |
| {
 | |
| 	posix_acl_xattr_header *header = (posix_acl_xattr_header *)value;
 | |
| 	posix_acl_xattr_entry *entry = (posix_acl_xattr_entry *)(header+1), *end;
 | |
| 	int count;
 | |
| 	struct posix_acl *acl;
 | |
| 	struct posix_acl_entry *acl_e;
 | |
| 
 | |
| 	if (!value)
 | |
| 		return NULL;
 | |
| 	if (size < sizeof(posix_acl_xattr_header))
 | |
| 		 return ERR_PTR(-EINVAL);
 | |
| 	if (header->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION))
 | |
| 		return ERR_PTR(-EOPNOTSUPP);
 | |
| 
 | |
| 	count = posix_acl_xattr_count(size);
 | |
| 	if (count < 0)
 | |
| 		return ERR_PTR(-EINVAL);
 | |
| 	if (count == 0)
 | |
| 		return NULL;
 | |
| 	
 | |
| 	acl = posix_acl_alloc(count, GFP_NOFS);
 | |
| 	if (!acl)
 | |
| 		return ERR_PTR(-ENOMEM);
 | |
| 	acl_e = acl->a_entries;
 | |
| 	
 | |
| 	for (end = entry + count; entry != end; acl_e++, entry++) {
 | |
| 		acl_e->e_tag  = le16_to_cpu(entry->e_tag);
 | |
| 		acl_e->e_perm = le16_to_cpu(entry->e_perm);
 | |
| 
 | |
| 		switch(acl_e->e_tag) {
 | |
| 			case ACL_USER_OBJ:
 | |
| 			case ACL_GROUP_OBJ:
 | |
| 			case ACL_MASK:
 | |
| 			case ACL_OTHER:
 | |
| 				break;
 | |
| 
 | |
| 			case ACL_USER:
 | |
| 				acl_e->e_uid =
 | |
| 					make_kuid(user_ns,
 | |
| 						  le32_to_cpu(entry->e_id));
 | |
| 				if (!uid_valid(acl_e->e_uid))
 | |
| 					goto fail;
 | |
| 				break;
 | |
| 			case ACL_GROUP:
 | |
| 				acl_e->e_gid =
 | |
| 					make_kgid(user_ns,
 | |
| 						  le32_to_cpu(entry->e_id));
 | |
| 				if (!gid_valid(acl_e->e_gid))
 | |
| 					goto fail;
 | |
| 				break;
 | |
| 
 | |
| 			default:
 | |
| 				goto fail;
 | |
| 		}
 | |
| 	}
 | |
| 	return acl;
 | |
| 
 | |
| fail:
 | |
| 	posix_acl_release(acl);
 | |
| 	return ERR_PTR(-EINVAL);
 | |
| }
 | |
| EXPORT_SYMBOL (posix_acl_from_xattr);
 | |
| 
 | |
| /*
 | |
|  * Convert from in-memory to extended attribute representation.
 | |
|  */
 | |
| int
 | |
| posix_acl_to_xattr(struct user_namespace *user_ns, const struct posix_acl *acl,
 | |
| 		   void *buffer, size_t size)
 | |
| {
 | |
| 	posix_acl_xattr_header *ext_acl = (posix_acl_xattr_header *)buffer;
 | |
| 	posix_acl_xattr_entry *ext_entry = ext_acl->a_entries;
 | |
| 	int real_size, n;
 | |
| 
 | |
| 	real_size = posix_acl_xattr_size(acl->a_count);
 | |
| 	if (!buffer)
 | |
| 		return real_size;
 | |
| 	if (real_size > size)
 | |
| 		return -ERANGE;
 | |
| 	
 | |
| 	ext_acl->a_version = cpu_to_le32(POSIX_ACL_XATTR_VERSION);
 | |
| 
 | |
| 	for (n=0; n < acl->a_count; n++, ext_entry++) {
 | |
| 		const struct posix_acl_entry *acl_e = &acl->a_entries[n];
 | |
| 		ext_entry->e_tag  = cpu_to_le16(acl_e->e_tag);
 | |
| 		ext_entry->e_perm = cpu_to_le16(acl_e->e_perm);
 | |
| 		switch(acl_e->e_tag) {
 | |
| 		case ACL_USER:
 | |
| 			ext_entry->e_id =
 | |
| 				cpu_to_le32(from_kuid(user_ns, acl_e->e_uid));
 | |
| 			break;
 | |
| 		case ACL_GROUP:
 | |
| 			ext_entry->e_id =
 | |
| 				cpu_to_le32(from_kgid(user_ns, acl_e->e_gid));
 | |
| 			break;
 | |
| 		default:
 | |
| 			ext_entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID);
 | |
| 			break;
 | |
| 		}
 | |
| 	}
 | |
| 	return real_size;
 | |
| }
 | |
| EXPORT_SYMBOL (posix_acl_to_xattr);
 | |
| 
 | |
| static int
 | |
| posix_acl_xattr_get(struct dentry *dentry, const char *name,
 | |
| 		void *value, size_t size, int type)
 | |
| {
 | |
| 	struct posix_acl *acl;
 | |
| 	int error;
 | |
| 
 | |
| 	if (!IS_POSIXACL(dentry->d_inode))
 | |
| 		return -EOPNOTSUPP;
 | |
| 	if (S_ISLNK(dentry->d_inode->i_mode))
 | |
| 		return -EOPNOTSUPP;
 | |
| 
 | |
| 	acl = get_acl(dentry->d_inode, type);
 | |
| 	if (IS_ERR(acl))
 | |
| 		return PTR_ERR(acl);
 | |
| 	if (acl == NULL)
 | |
| 		return -ENODATA;
 | |
| 
 | |
| 	error = posix_acl_to_xattr(&init_user_ns, acl, value, size);
 | |
| 	posix_acl_release(acl);
 | |
| 
 | |
| 	return error;
 | |
| }
 | |
| 
 | |
| static int
 | |
| posix_acl_xattr_set(struct dentry *dentry, const char *name,
 | |
| 		const void *value, size_t size, int flags, int type)
 | |
| {
 | |
| 	struct inode *inode = dentry->d_inode;
 | |
| 	struct posix_acl *acl = NULL;
 | |
| 	int ret;
 | |
| 
 | |
| 	if (!IS_POSIXACL(inode))
 | |
| 		return -EOPNOTSUPP;
 | |
| 	if (!inode->i_op->set_acl)
 | |
| 		return -EOPNOTSUPP;
 | |
| 
 | |
| 	if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
 | |
| 		return value ? -EACCES : 0;
 | |
| 	if (!inode_owner_or_capable(inode))
 | |
| 		return -EPERM;
 | |
| 
 | |
| 	if (value) {
 | |
| 		acl = posix_acl_from_xattr(&init_user_ns, value, size);
 | |
| 		if (IS_ERR(acl))
 | |
| 			return PTR_ERR(acl);
 | |
| 
 | |
| 		if (acl) {
 | |
| 			ret = posix_acl_valid(acl);
 | |
| 			if (ret)
 | |
| 				goto out;
 | |
| 		}
 | |
| 	}
 | |
| 
 | |
| 	ret = inode->i_op->set_acl(inode, acl, type);
 | |
| out:
 | |
| 	posix_acl_release(acl);
 | |
| 	return ret;
 | |
| }
 | |
| 
 | |
| static size_t
 | |
| posix_acl_xattr_list(struct dentry *dentry, char *list, size_t list_size,
 | |
| 		const char *name, size_t name_len, int type)
 | |
| {
 | |
| 	const char *xname;
 | |
| 	size_t size;
 | |
| 
 | |
| 	if (!IS_POSIXACL(dentry->d_inode))
 | |
| 		return -EOPNOTSUPP;
 | |
| 	if (S_ISLNK(dentry->d_inode->i_mode))
 | |
| 		return -EOPNOTSUPP;
 | |
| 
 | |
| 	if (type == ACL_TYPE_ACCESS)
 | |
| 		xname = POSIX_ACL_XATTR_ACCESS;
 | |
| 	else
 | |
| 		xname = POSIX_ACL_XATTR_DEFAULT;
 | |
| 
 | |
| 	size = strlen(xname) + 1;
 | |
| 	if (list && size <= list_size)
 | |
| 		memcpy(list, xname, size);
 | |
| 	return size;
 | |
| }
 | |
| 
 | |
| const struct xattr_handler posix_acl_access_xattr_handler = {
 | |
| 	.prefix = POSIX_ACL_XATTR_ACCESS,
 | |
| 	.flags = ACL_TYPE_ACCESS,
 | |
| 	.list = posix_acl_xattr_list,
 | |
| 	.get = posix_acl_xattr_get,
 | |
| 	.set = posix_acl_xattr_set,
 | |
| };
 | |
| EXPORT_SYMBOL_GPL(posix_acl_access_xattr_handler);
 | |
| 
 | |
| const struct xattr_handler posix_acl_default_xattr_handler = {
 | |
| 	.prefix = POSIX_ACL_XATTR_DEFAULT,
 | |
| 	.flags = ACL_TYPE_DEFAULT,
 | |
| 	.list = posix_acl_xattr_list,
 | |
| 	.get = posix_acl_xattr_get,
 | |
| 	.set = posix_acl_xattr_set,
 | |
| };
 | |
| EXPORT_SYMBOL_GPL(posix_acl_default_xattr_handler);
 | |
| 
 | |
| int simple_set_acl(struct inode *inode, struct posix_acl *acl, int type)
 | |
| {
 | |
| 	int error;
 | |
| 
 | |
| 	if (type == ACL_TYPE_ACCESS) {
 | |
| 		error = posix_acl_equiv_mode(acl, &inode->i_mode);
 | |
| 		if (error < 0)
 | |
| 			return 0;
 | |
| 		if (error == 0)
 | |
| 			acl = NULL;
 | |
| 	}
 | |
| 
 | |
| 	inode->i_ctime = CURRENT_TIME;
 | |
| 	set_cached_acl(inode, type, acl);
 | |
| 	return 0;
 | |
| }
 | |
| 
 | |
| int simple_acl_create(struct inode *dir, struct inode *inode)
 | |
| {
 | |
| 	struct posix_acl *default_acl, *acl;
 | |
| 	int error;
 | |
| 
 | |
| 	error = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
 | |
| 	if (error)
 | |
| 		return error;
 | |
| 
 | |
| 	set_cached_acl(inode, ACL_TYPE_DEFAULT, default_acl);
 | |
| 	set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
 | |
| 
 | |
| 	if (default_acl)
 | |
| 		posix_acl_release(default_acl);
 | |
| 	if (acl)
 | |
| 		posix_acl_release(acl);
 | |
| 	return 0;
 | |
| }
 |