Commit f71381fc authored by Ian Kent's avatar Ian Kent Committed by Andrew Morton
Browse files

autofs: use inode permission method for write access 

Patch series "autofs: misc patches".

This series contains several patches that resulted mostly from comments
made by Al Viro (quite a long time ago now).


This patch (of 5):

Eliminate some code duplication from mkdir/rmdir/symlink/unlink methods by
using the inode operation .permission().

Link: https://lkml.kernel.org/r/165724445154.30914.10970894936827635879.stgit@donald.themaw.net
Link: https://lkml.kernel.org/r/165724458096.30914.13499431569758625806.stgit@donald.themaw.net


Signed-off-by: default avatarIan Kent <raven@themaw.net>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 55656016

fs/autofs/root.c

+22 −41
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ 


#include "autofs_i.h"



static int autofs_dir_permission(struct user_namespace *, struct inode *, int);

static int autofs_dir_symlink(struct user_namespace *, struct inode *,

			      struct dentry *, const char *);

static int autofs_dir_unlink(struct inode *, struct dentry *);
@@ -50,6 +51,7 @@ const struct file_operations autofs_dir_operations = { 


const struct inode_operations autofs_dir_inode_operations = {

	.lookup		= autofs_lookup,

	.permission	= autofs_dir_permission,

	.unlink		= autofs_dir_unlink,

	.symlink	= autofs_dir_symlink,

	.mkdir		= autofs_dir_mkdir,
@@ -526,18 +528,11 @@ static struct dentry *autofs_lookup(struct inode *dir, 
	return NULL;

}



static int autofs_dir_symlink(struct user_namespace *mnt_userns,

			      struct inode *dir, struct dentry *dentry,

			      const char *symname)

static int autofs_dir_permission(struct user_namespace *mnt_userns,

				 struct inode *inode, int mask)

{

	struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);

	struct autofs_info *ino = autofs_dentry_ino(dentry);

	struct autofs_info *p_ino;

	struct inode *inode;

	size_t size = strlen(symname);

	char *cp;



	pr_debug("%s <- %pd\n", symname, dentry);

	if (mask & MAY_WRITE) {

		struct autofs_sb_info *sbi = autofs_sbi(inode->i_sb);



		if (!autofs_oz_mode(sbi))

			return -EACCES;
@@ -548,6 +543,22 @@ static int autofs_dir_symlink(struct user_namespace *mnt_userns, 
		 */

		if (sbi->flags & AUTOFS_SBI_CATATONIC)

			return -EACCES;

	}



	return generic_permission(mnt_userns, inode, mask);

}



static int autofs_dir_symlink(struct user_namespace *mnt_userns,

			      struct inode *dir, struct dentry *dentry,

			      const char *symname)

{

	struct autofs_info *ino = autofs_dentry_ino(dentry);

	struct autofs_info *p_ino;

	struct inode *inode;

	size_t size = strlen(symname);

	char *cp;



	pr_debug("%s <- %pd\n", symname, dentry);



	BUG_ON(!ino);
@@ -601,16 +612,6 @@ static int autofs_dir_unlink(struct inode *dir, struct dentry *dentry) 
	struct autofs_info *ino = autofs_dentry_ino(dentry);

	struct autofs_info *p_ino;



	if (!autofs_oz_mode(sbi))

		return -EACCES;



	/* autofs_oz_mode() needs to allow path walks when the

	 * autofs mount is catatonic but the state of an autofs

	 * file system needs to be preserved over restarts.

	 */

	if (sbi->flags & AUTOFS_SBI_CATATONIC)

		return -EACCES;



	ino->count--;

	p_ino = autofs_dentry_ino(dentry->d_parent);

	p_ino->count--;
@@ -683,16 +684,6 @@ static int autofs_dir_rmdir(struct inode *dir, struct dentry *dentry) 


	pr_debug("dentry %p, removing %pd\n", dentry, dentry);



	if (!autofs_oz_mode(sbi))

		return -EACCES;



	/* autofs_oz_mode() needs to allow path walks when the

	 * autofs mount is catatonic but the state of an autofs

	 * file system needs to be preserved over restarts.

	 */

	if (sbi->flags & AUTOFS_SBI_CATATONIC)

		return -EACCES;



	if (ino->count != 1)

		return -ENOTEMPTY;
@@ -726,16 +717,6 @@ static int autofs_dir_mkdir(struct user_namespace *mnt_userns, 
	struct autofs_info *p_ino;

	struct inode *inode;



	if (!autofs_oz_mode(sbi))

		return -EACCES;



	/* autofs_oz_mode() needs to allow path walks when the

	 * autofs mount is catatonic but the state of an autofs

	 * file system needs to be preserved over restarts.

	 */

	if (sbi->flags & AUTOFS_SBI_CATATONIC)

		return -EACCES;



	pr_debug("dentry %p, creating %pd\n", dentry, dentry);



	BUG_ON(!ino);