Commit 90e4fc88 authored by Al Viro's avatar Al Viro
Browse files

9p: don't bother with __getname() in ->follow_link() 



We copy there a kmalloc'ed string and proceed to kfree that string immediately
after that.  Easier to just feed that string to nd_set_link() and _not_
kfree it until ->put_link() (which becomes kfree_put_link() in that case).

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent b46c267e

fs/9p/v9fs.h

+0 −2
Original line number Diff line number Diff line
@@ -149,8 +149,6 @@ extern int v9fs_vfs_unlink(struct inode *i, struct dentry *d); 
extern int v9fs_vfs_rmdir(struct inode *i, struct dentry *d);

extern int v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,

			struct inode *new_dir, struct dentry *new_dentry);

extern void v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd,

			void *p);

extern struct inode *v9fs_inode_from_fid(struct v9fs_session_info *v9ses,

					 struct p9_fid *fid,

					 struct super_block *sb, int new);

fs/9p/vfs_inode.c

+18 −75
Original line number Diff line number Diff line
@@ -1224,102 +1224,45 @@ ino_t v9fs_qid2ino(struct p9_qid *qid) 
}



/**

 * v9fs_readlink - read a symlink's location (internal version)

 * v9fs_vfs_follow_link - follow a symlink path

 * @dentry: dentry for symlink

 * @buffer: buffer to load symlink location into

 * @buflen: length of buffer

 * @nd: nameidata

 *

 */



static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)

static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)

{

	int retval;



	struct v9fs_session_info *v9ses;

	struct p9_fid *fid;

	struct v9fs_session_info *v9ses = v9fs_dentry2v9ses(dentry);

	struct p9_fid *fid = v9fs_fid_lookup(dentry);

	struct p9_wstat *st;



	p9_debug(P9_DEBUG_VFS, "%pd\n", dentry);

	retval = -EPERM;

	v9ses = v9fs_dentry2v9ses(dentry);

	fid = v9fs_fid_lookup(dentry);



	if (IS_ERR(fid))

		return PTR_ERR(fid);

		return ERR_CAST(fid);



	if (!v9fs_proto_dotu(v9ses))

		return -EBADF;

		return ERR_PTR(-EBADF);



	st = p9_client_stat(fid);

	if (IS_ERR(st))

		return PTR_ERR(st);

		return ERR_CAST(st);



	if (!(st->mode & P9_DMSYMLINK)) {

		retval = -EINVAL;

		goto done;

	}



	/* copy extension buffer into buffer */

	retval = min(strlen(st->extension)+1, (size_t)buflen);

	memcpy(buffer, st->extension, retval);



	p9_debug(P9_DEBUG_VFS, "%pd -> %s (%.*s)\n",

		 dentry, st->extension, buflen, buffer);



done:

		p9stat_free(st);

		kfree(st);

	return retval;

		return ERR_PTR(-EINVAL);

	}

	if (strlen(st->extension) >= PATH_MAX)

		st->extension[PATH_MAX - 1] = '\0';



/**

 * v9fs_vfs_follow_link - follow a symlink path

 * @dentry: dentry for symlink

 * @nd: nameidata

 *

 */



static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)

{

	int len = 0;

	char *link = __getname();



	p9_debug(P9_DEBUG_VFS, "%pd\n", dentry);



	if (!link)

		link = ERR_PTR(-ENOMEM);

	else {

		len = v9fs_readlink(dentry, link, PATH_MAX);



		if (len < 0) {

			__putname(link);

			link = ERR_PTR(len);

		} else

			link[min(len, PATH_MAX-1)] = 0;

	}

	nd_set_link(nd, link);



	nd_set_link(nd, st->extension);

	st->extension = NULL;

	p9stat_free(st);

	kfree(st);

	return NULL;

}



/**

 * v9fs_vfs_put_link - release a symlink path

 * @dentry: dentry for symlink

 * @nd: nameidata

 * @p: unused

 *

 */



void

v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)

{

	char *s = nd_get_link(nd);



	p9_debug(P9_DEBUG_VFS, " %pd %s\n",

		 dentry, IS_ERR(s) ? "<error>" : s);

	if (!IS_ERR(s))

		__putname(s);

}



/**

 * v9fs_vfs_mkspecial - create a special file

 * @dir: inode to create special file in
@@ -1514,7 +1457,7 @@ static const struct inode_operations v9fs_file_inode_operations = { 
static const struct inode_operations v9fs_symlink_inode_operations = {

	.readlink = generic_readlink,

	.follow_link = v9fs_vfs_follow_link,

	.put_link = v9fs_vfs_put_link,

	.put_link = kfree_put_link,

	.getattr = v9fs_vfs_getattr,

	.setattr = v9fs_vfs_setattr,

};

fs/9p/vfs_inode_dotl.c

+8 −23
Original line number Diff line number Diff line
@@ -912,33 +912,18 @@ error: 
static void *

v9fs_vfs_follow_link_dotl(struct dentry *dentry, struct nameidata *nd)

{

	int retval;

	struct p9_fid *fid;

	char *link = __getname();

	struct p9_fid *fid = v9fs_fid_lookup(dentry);

	char *target;

	int retval;



	p9_debug(P9_DEBUG_VFS, "%pd\n", dentry);



	if (!link) {

		link = ERR_PTR(-ENOMEM);

		goto ndset;

	}

	fid = v9fs_fid_lookup(dentry);

	if (IS_ERR(fid)) {

		__putname(link);

		link = ERR_CAST(fid);

		goto ndset;

	}

	if (IS_ERR(fid))

		return ERR_CAST(fid);

	retval = p9_client_readlink(fid, &target);

	if (!retval) {

		strcpy(link, target);

		kfree(target);

		goto ndset;

	}

	__putname(link);

	link = ERR_PTR(retval);

ndset:

	nd_set_link(nd, link);

	if (retval)

		return ERR_PTR(retval);

	nd_set_link(nd, target);

	return NULL;

}
@@ -1006,7 +991,7 @@ const struct inode_operations v9fs_file_inode_operations_dotl = { 
const struct inode_operations v9fs_symlink_inode_operations_dotl = {

	.readlink = generic_readlink,

	.follow_link = v9fs_vfs_follow_link_dotl,

	.put_link = v9fs_vfs_put_link,

	.put_link = kfree_put_link,

	.getattr = v9fs_vfs_getattr_dotl,

	.setattr = v9fs_vfs_setattr_dotl,

	.setxattr = generic_setxattr,

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