From 408bd629badbd4353b238ab6f58001529b274d73 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 3 May 2012 09:34:20 -0400 Subject: 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 --- fs/ecryptfs/inode.c | 48 +++++++++--------------------------------------- 1 file changed, 9 insertions(+), 39 deletions(-) diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index ab35b113003b..a07441a0a878 100644 --- a/fs/ecryptfs/inode.c +++ b/fs/ecryptfs/inode.c @@ -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 @@ out: } 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, -- cgit v1.2.3-59-g8ed1b