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Commit 408bd629 authored by Al Viro's avatar Al Viro
Browse files

get rid of pointless allocations and copying in ecryptfs_follow_link() 



switch to generic_readlink(), while we are at it

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 28fe3c19

fs/ecryptfs/inode.c

+9 −39
Original line number Diff line number Diff line
@@ -660,11 +660,10 @@ static int ecryptfs_readlink_lower(struct dentry *dentry, char **buf, 
{

	struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);

	char *lower_buf;

	size_t lower_bufsiz = PATH_MAX;

	mm_segment_t old_fs;

	int rc;



	lower_buf = kmalloc(lower_bufsiz, GFP_KERNEL);

	lower_buf = kmalloc(PATH_MAX, GFP_KERNEL);

	if (!lower_buf) {

		rc = -ENOMEM;

		goto out;
@@ -673,58 +672,29 @@ static int ecryptfs_readlink_lower(struct dentry *dentry, char **buf, 
	set_fs(get_ds());

	rc = lower_dentry->d_inode->i_op->readlink(lower_dentry,

						   (char __user *)lower_buf,

						   lower_bufsiz);

						   PATH_MAX);

	set_fs(old_fs);

	if (rc < 0)

		goto out;

	lower_bufsiz = rc;

	rc = ecryptfs_decode_and_decrypt_filename(buf, bufsiz, dentry,

						  lower_buf, lower_bufsiz);

						  lower_buf, rc);

out:

	kfree(lower_buf);

	return rc;

}



static int

ecryptfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz)

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

{

	char *kbuf;

	size_t kbufsiz, copied;

	char *buf;

	size_t len = PATH_MAX;

	int rc;



	rc = ecryptfs_readlink_lower(dentry, &kbuf, &kbufsiz);

	rc = ecryptfs_readlink_lower(dentry, &buf, &len);

	if (rc)

		goto out;

	copied = min_t(size_t, bufsiz, kbufsiz);

	rc = copy_to_user(buf, kbuf, copied) ? -EFAULT : copied;

	kfree(kbuf);

	fsstack_copy_attr_atime(dentry->d_inode,

				ecryptfs_dentry_to_lower(dentry)->d_inode);

out:

	return rc;

}



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

{

	char *buf;

	int len = PAGE_SIZE, rc;

	mm_segment_t old_fs;



	/* Released in ecryptfs_put_link(); only release here on error */

	buf = kmalloc(len, GFP_KERNEL);

	if (!buf) {

		buf = ERR_PTR(-ENOMEM);

		goto out;

	}

	old_fs = get_fs();

	set_fs(get_ds());

	rc = dentry->d_inode->i_op->readlink(dentry, (char __user *)buf, len);

	set_fs(old_fs);

	if (rc < 0) {

		kfree(buf);

		buf = ERR_PTR(rc);

	} else

		buf[rc] = '\0';

	buf[len] = '\0';

out:

	nd_set_link(nd, buf);

	return NULL;
@@ -1153,7 +1123,7 @@ static int ecryptfs_removexattr(struct dentry *dentry, const char *name) 
}



const struct inode_operations ecryptfs_symlink_iops = {

	.readlink = ecryptfs_readlink,

	.readlink = generic_readlink,

	.follow_link = ecryptfs_follow_link,

	.put_link = ecryptfs_put_link,

	.permission = ecryptfs_permission,