get rid of pointless allocations and copying in ecryptfs_follow_link()
switch to generic_readlink(), while we are at it
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index ab35b11..a07441a 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -660,11 +660,10 @@
{
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 @@
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)
-{
- char *kbuf;
- size_t kbufsiz, copied;
- int rc;
-
- rc = ecryptfs_readlink_lower(dentry, &kbuf, &kbufsiz);
- 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;
+ size_t len = PATH_MAX;
+ int rc;
- /* Released in ecryptfs_put_link(); only release here on error */
- buf = kmalloc(len, GFP_KERNEL);
- if (!buf) {
- buf = ERR_PTR(-ENOMEM);
+ rc = ecryptfs_readlink_lower(dentry, &buf, &len);
+ if (rc)
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';
+ fsstack_copy_attr_atime(dentry->d_inode,
+ ecryptfs_dentry_to_lower(dentry)->d_inode);
+ buf[len] = '\0';
out:
nd_set_link(nd, buf);
return NULL;
@@ -1153,7 +1123,7 @@
}
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,