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Commit 1c7c474c authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Al Viro
Browse files

make generic_acl slightly more generic 



Now that we cache the ACL pointers in the generic inode all the generic_acl
cruft can go away and generic_acl.c can directly implement xattr handlers
dealing with the full Posix ACL semantics for in-memory filesystems.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 431547b3

fs/generic_acl.c

+89 −69
Original line number Diff line number Diff line 
/*

 * fs/generic_acl.c

 *

 * (C) 2005 Andreas Gruenbacher <agruen@suse.de>

 *

 * This file is released under the GPL.

 *

 * Generic ACL support for in-memory filesystems.

 */



#include <linux/sched.h>

#include <linux/fs.h>

#include <linux/generic_acl.h>

#include <linux/posix_acl.h>

#include <linux/posix_acl_xattr.h>



/**

 * generic_acl_list  -  Generic xattr_handler->list() operation

 * @ops:	Filesystem specific getacl and setacl callbacks

 */

size_t

generic_acl_list(struct inode *inode, struct generic_acl_operations *ops,

		 int type, char *list, size_t list_size)



static size_t

generic_acl_list(struct dentry *dentry, char *list, size_t list_size,

		const char *name, size_t name_len, int type)

{

	struct posix_acl *acl;

	const char *name;

	const char *xname;

	size_t size;



	acl = ops->getacl(inode, type);

	acl = get_cached_acl(dentry->d_inode, type);

	if (!acl)

		return 0;

	posix_acl_release(acl);



	switch (type) {

	case ACL_TYPE_ACCESS:

			name = POSIX_ACL_XATTR_ACCESS;

		xname = POSIX_ACL_XATTR_ACCESS;

		break;



	case ACL_TYPE_DEFAULT:

			name = POSIX_ACL_XATTR_DEFAULT;

		xname = POSIX_ACL_XATTR_DEFAULT;

		break;



	default:

		return 0;

	}

	size = strlen(name) + 1;

	size = strlen(xname) + 1;

	if (list && size <= list_size)

		memcpy(list, name, size);

		memcpy(list, xname, size);

	return size;

}



/**

 * generic_acl_get  -  Generic xattr_handler->get() operation

 * @ops:	Filesystem specific getacl and setacl callbacks

 */

int

generic_acl_get(struct inode *inode, struct generic_acl_operations *ops,

		int type, void *buffer, size_t size)

static int

generic_acl_get(struct dentry *dentry, const char *name, void *buffer,

		     size_t size, int type)

{

	struct posix_acl *acl;

	int error;



	acl = ops->getacl(inode, type);

	if (strcmp(name, "") != 0)

		return -EINVAL;



	acl = get_cached_acl(dentry->d_inode, type);

	if (!acl)

		return -ENODATA;

	error = posix_acl_to_xattr(acl, buffer, size);
@@ -65,17 +61,16 @@ generic_acl_get(struct inode *inode, struct generic_acl_operations *ops, 
	return error;

}



/**

 * generic_acl_set  -  Generic xattr_handler->set() operation

 * @ops:	Filesystem specific getacl and setacl callbacks

 */

int

generic_acl_set(struct inode *inode, struct generic_acl_operations *ops,

		int type, const void *value, size_t size)

static int

generic_acl_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 error;



	if (strcmp(name, "") != 0)

		return -EINVAL;

	if (S_ISLNK(inode->i_mode))

		return -EOPNOTSUPP;

	if (!is_owner_or_cap(inode))
@@ -103,7 +98,6 @@ generic_acl_set(struct inode *inode, struct generic_acl_operations *ops, 
				acl = NULL;

			}

			break;



		case ACL_TYPE_DEFAULT:

			if (!S_ISDIR(inode->i_mode)) {

				error = -EINVAL;
@@ -112,7 +106,7 @@ generic_acl_set(struct inode *inode, struct generic_acl_operations *ops, 
			break;

		}

	}

	ops->setacl(inode, type, acl);

	set_cached_acl(inode, type, acl);

	error = 0;

failed:

	posix_acl_release(acl);
@@ -121,14 +115,12 @@ generic_acl_set(struct inode *inode, struct generic_acl_operations *ops, 


/**

 * generic_acl_init  -  Take care of acl inheritance at @inode create time

 * @ops:	Filesystem specific getacl and setacl callbacks

 *

 * Files created inside a directory with a default ACL inherit the

 * directory's default ACL.

 */

int

generic_acl_init(struct inode *inode, struct inode *dir,

		 struct generic_acl_operations *ops)

generic_acl_init(struct inode *inode, struct inode *dir)

{

	struct posix_acl *acl = NULL;

	mode_t mode = inode->i_mode;
@@ -136,7 +128,7 @@ generic_acl_init(struct inode *inode, struct inode *dir, 


	inode->i_mode = mode & ~current_umask();

	if (!S_ISLNK(inode->i_mode))

		acl = ops->getacl(dir, ACL_TYPE_DEFAULT);

		acl = get_cached_acl(dir, ACL_TYPE_DEFAULT);

	if (acl) {

		struct posix_acl *clone;
@@ -145,7 +137,7 @@ generic_acl_init(struct inode *inode, struct inode *dir, 
			error = -ENOMEM;

			if (!clone)

				goto cleanup;

			ops->setacl(inode, ACL_TYPE_DEFAULT, clone);

			set_cached_acl(inode, ACL_TYPE_DEFAULT, clone);

			posix_acl_release(clone);

		}

		clone = posix_acl_clone(acl, GFP_KERNEL);
@@ -156,7 +148,7 @@ generic_acl_init(struct inode *inode, struct inode *dir, 
		if (error >= 0) {

			inode->i_mode = mode;

			if (error > 0)

				ops->setacl(inode, ACL_TYPE_ACCESS, clone);

				set_cached_acl(inode, ACL_TYPE_ACCESS, clone);

		}

		posix_acl_release(clone);

	}
@@ -169,20 +161,19 @@ generic_acl_init(struct inode *inode, struct inode *dir, 


/**

 * generic_acl_chmod  -  change the access acl of @inode upon chmod()

 * @ops:	FIlesystem specific getacl and setacl callbacks

 *

 * A chmod also changes the permissions of the owner, group/mask, and

 * other ACL entries.

 */

int

generic_acl_chmod(struct inode *inode, struct generic_acl_operations *ops)

generic_acl_chmod(struct inode *inode)

{

	struct posix_acl *acl, *clone;

	int error = 0;



	if (S_ISLNK(inode->i_mode))

		return -EOPNOTSUPP;

	acl = ops->getacl(inode, ACL_TYPE_ACCESS);

	acl = get_cached_acl(inode, ACL_TYPE_ACCESS);

	if (acl) {

		clone = posix_acl_clone(acl, GFP_KERNEL);

		posix_acl_release(acl);
@@ -190,8 +181,37 @@ generic_acl_chmod(struct inode *inode, struct generic_acl_operations *ops) 
			return -ENOMEM;

		error = posix_acl_chmod_masq(clone, inode->i_mode);

		if (!error)

			ops->setacl(inode, ACL_TYPE_ACCESS, clone);

			set_cached_acl(inode, ACL_TYPE_ACCESS, clone);

		posix_acl_release(clone);

	}

	return error;

}



int

generic_check_acl(struct inode *inode, int mask)

{

	struct posix_acl *acl = get_cached_acl(inode, ACL_TYPE_ACCESS);



	if (acl) {

		int error = posix_acl_permission(inode, acl, mask);

		posix_acl_release(acl);

		return error;

	}

	return -EAGAIN;

}



struct xattr_handler generic_acl_access_handler = {

	.prefix = POSIX_ACL_XATTR_ACCESS,

	.flags	= ACL_TYPE_ACCESS,

	.list	= generic_acl_list,

	.get	= generic_acl_get,

	.set	= generic_acl_set,

};



struct xattr_handler generic_acl_default_handler = {

	.prefix = POSIX_ACL_XATTR_DEFAULT,

	.flags	= ACL_TYPE_DEFAULT,

	.list	= generic_acl_list,

	.get	= generic_acl_get,

	.set	= generic_acl_set,

};

include/linux/generic_acl.h

+10 −31
Original line number Diff line number Diff line 
/*

 * include/linux/generic_acl.h

 *

 * (C) 2005 Andreas Gruenbacher <agruen@suse.de>

 *

 * This file is released under the GPL.

 */

#ifndef LINUX_GENERIC_ACL_H

#define LINUX_GENERIC_ACL_H



#ifndef GENERIC_ACL_H

#define GENERIC_ACL_H

#include <linux/xattr.h>



#include <linux/posix_acl.h>

#include <linux/posix_acl_xattr.h>

struct inode;



/**

 * struct generic_acl_operations  -  filesystem operations

 *

 * Filesystems must make these operations available to the generic

 * operations.

 */

struct generic_acl_operations {

	struct posix_acl *(*getacl)(struct inode *, int);

	void (*setacl)(struct inode *, int, struct posix_acl *);

};

extern struct xattr_handler generic_acl_access_handler;

extern struct xattr_handler generic_acl_default_handler;



size_t generic_acl_list(struct inode *, struct generic_acl_operations *, int,

			char *, size_t);

int generic_acl_get(struct inode *, struct generic_acl_operations *, int,

		    void *, size_t);

int generic_acl_set(struct inode *, struct generic_acl_operations *, int,

		    const void *, size_t);

int generic_acl_init(struct inode *, struct inode *,

		     struct generic_acl_operations *);

int generic_acl_chmod(struct inode *, struct generic_acl_operations *);

int generic_acl_init(struct inode *, struct inode *);

int generic_acl_chmod(struct inode *);

int generic_check_acl(struct inode *inode, int mask);



#endif
 
#endif /* LINUX_GENERIC_ACL_H */

include/linux/shmem_fs.h

+0 −16
Original line number Diff line number Diff line
@@ -41,20 +41,4 @@ static inline struct shmem_inode_info *SHMEM_I(struct inode *inode) 
extern int init_tmpfs(void);

extern int shmem_fill_super(struct super_block *sb, void *data, int silent);



#ifdef CONFIG_TMPFS_POSIX_ACL

int shmem_check_acl(struct inode *, int);

int shmem_acl_init(struct inode *, struct inode *);



extern struct xattr_handler shmem_xattr_acl_access_handler;

extern struct xattr_handler shmem_xattr_acl_default_handler;



extern struct generic_acl_operations shmem_acl_ops;



#else

static inline int shmem_acl_init(struct inode *inode, struct inode *dir)

{

	return 0;

}

#endif  /* CONFIG_TMPFS_POSIX_ACL */



#endif

mm/Makefile

+0 −1
Original line number Diff line number Diff line
@@ -22,7 +22,6 @@ obj-$(CONFIG_HUGETLBFS) += hugetlb.o 
obj-$(CONFIG_NUMA) 	+= mempolicy.o

obj-$(CONFIG_SPARSEMEM)	+= sparse.o

obj-$(CONFIG_SPARSEMEM_VMEMMAP) += sparse-vmemmap.o

obj-$(CONFIG_TMPFS_POSIX_ACL) += shmem_acl.o

obj-$(CONFIG_SLOB) += slob.o

obj-$(CONFIG_MMU_NOTIFIER) += mmu_notifier.o

obj-$(CONFIG_KSM) += ksm.o

mm/shmem.c

+10 −7
Original line number Diff line number Diff line
@@ -41,6 +41,7 @@ static struct vfsmount *shm_mnt; 


#include <linux/xattr.h>

#include <linux/exportfs.h>

#include <linux/posix_acl.h>

#include <linux/generic_acl.h>

#include <linux/mman.h>

#include <linux/string.h>
@@ -809,7 +810,7 @@ static int shmem_notify_change(struct dentry *dentry, struct iattr *attr) 
		error = inode_setattr(inode, attr);

#ifdef CONFIG_TMPFS_POSIX_ACL

	if (!error && (attr->ia_valid & ATTR_MODE))

		error = generic_acl_chmod(inode, &shmem_acl_ops);

		error = generic_acl_chmod(inode);

#endif

	if (page)

		page_cache_release(page);
@@ -1823,11 +1824,13 @@ shmem_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) 
				return error;

			}

		}

		error = shmem_acl_init(inode, dir);

#ifdef CONFIG_TMPFS_POSIX_ACL

		error = generic_acl_init(inode, dir);

		if (error) {

			iput(inode);

			return error;

		}

#endif

		if (dir->i_mode & S_ISGID) {

			inode->i_gid = dir->i_gid;

			if (S_ISDIR(mode))
@@ -2074,8 +2077,8 @@ static struct xattr_handler shmem_xattr_security_handler = { 
};



static struct xattr_handler *shmem_xattr_handlers[] = {

	&shmem_xattr_acl_access_handler,

	&shmem_xattr_acl_default_handler,

	&generic_acl_access_handler,

	&generic_acl_default_handler,

	&shmem_xattr_security_handler,

	NULL

};
@@ -2454,7 +2457,7 @@ static const struct inode_operations shmem_inode_operations = { 
	.getxattr	= generic_getxattr,

	.listxattr	= generic_listxattr,

	.removexattr	= generic_removexattr,

	.check_acl	= shmem_check_acl,

	.check_acl	= generic_check_acl,

#endif



};
@@ -2477,7 +2480,7 @@ static const struct inode_operations shmem_dir_inode_operations = { 
	.getxattr	= generic_getxattr,

	.listxattr	= generic_listxattr,

	.removexattr	= generic_removexattr,

	.check_acl	= shmem_check_acl,

	.check_acl	= generic_check_acl,

#endif

};
@@ -2488,7 +2491,7 @@ static const struct inode_operations shmem_special_inode_operations = { 
	.getxattr	= generic_getxattr,

	.listxattr	= generic_listxattr,

	.removexattr	= generic_removexattr,

	.check_acl	= shmem_check_acl,

	.check_acl	= generic_check_acl,

#endif

};