From: Miklos Szeredi <mszeredi@redhat.com>
To: linux-fsdevel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, Al Viro <viro@zeniv.linux.org.uk>
Subject: [PATCH 16/17] ovl: use vfs_get_link()
Date: Mon, 12 Sep 2016 21:29:18 +0200 [thread overview]
Message-ID: <1473708559-12714-17-git-send-email-mszeredi@redhat.com> (raw)
In-Reply-To: <1473708559-12714-1-git-send-email-mszeredi@redhat.com>
Resulting in a complete removal of a function basically implementing the
inverse of vfs_readlink().
As a bonus, now the proper security hook is also called.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
---
fs/overlayfs/copy_up.c | 45 ++++++---------------------------------------
fs/overlayfs/inode.c | 5 +----
2 files changed, 7 insertions(+), 43 deletions(-)
diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index a2d4c10dd74d..c3371d62d931 100644
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -167,39 +167,6 @@ out_fput:
return error;
}
-static char *ovl_read_symlink(struct dentry *realdentry)
-{
- int res;
- char *buf;
- struct inode *inode = realdentry->d_inode;
- mm_segment_t old_fs;
-
- res = -EINVAL;
- if (!inode->i_op->get_link)
- goto err;
-
- res = -ENOMEM;
- buf = (char *) __get_free_page(GFP_KERNEL);
- if (!buf)
- goto err;
-
- old_fs = get_fs();
- set_fs(get_ds());
- /* The cast to a user pointer is valid due to the set_fs() */
- res = vfs_readlink(realdentry, (char __user *)buf, PAGE_SIZE - 1);
- set_fs(old_fs);
- if (res < 0) {
- free_page((unsigned long) buf);
- goto err;
- }
- buf[res] = '\0';
-
- return buf;
-
-err:
- return ERR_PTR(res);
-}
-
static int ovl_set_timestamps(struct dentry *upperdentry, struct kstat *stat)
{
struct iattr attr = {
@@ -331,19 +298,21 @@ out_cleanup:
int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry,
struct path *lowerpath, struct kstat *stat)
{
+ DEFINE_DELAYED_CALL(done);
struct dentry *workdir = ovl_workdir(dentry);
int err;
struct kstat pstat;
struct path parentpath;
+ struct dentry *lowerdentry = lowerpath->dentry;
struct dentry *upperdir;
struct dentry *upperdentry;
const struct cred *old_cred;
- char *link = NULL;
+ const char *link = NULL;
if (WARN_ON(!workdir))
return -EROFS;
- ovl_do_check_copy_up(lowerpath->dentry);
+ ovl_do_check_copy_up(lowerdentry);
ovl_path_upper(parent, &parentpath);
upperdir = parentpath.dentry;
@@ -353,7 +322,7 @@ int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry,
return err;
if (S_ISLNK(stat->mode)) {
- link = ovl_read_symlink(lowerpath->dentry);
+ link = vfs_get_link(lowerdentry, d_inode(lowerdentry), &done);
if (IS_ERR(link))
return PTR_ERR(link);
}
@@ -381,9 +350,7 @@ int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry,
out_unlock:
unlock_rename(workdir, upperdir);
revert_creds(old_cred);
-
- if (link)
- free_page((unsigned long) link);
+ do_delayed_call(&done);
return err;
}
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index db8975f59021..6be9bb470fd9 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -164,11 +164,8 @@ static const char *ovl_get_link(struct dentry *dentry,
realdentry = ovl_dentry_real(dentry);
realinode = realdentry->d_inode;
- if (WARN_ON(!realinode->i_op->get_link))
- return ERR_PTR(-EPERM);
-
old_cred = ovl_override_creds(dentry->d_sb);
- p = realinode->i_op->get_link(realdentry, realinode, done);
+ p = vfs_get_link(realdentry, realinode, done);
revert_creds(old_cred);
return p;
}
--
2.5.5
next prev parent reply other threads:[~2016-09-12 19:29 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-12 19:29 [PATCH 00/17] clean up readlinks Miklos Szeredi
2016-09-12 19:29 ` [PATCH 01/17] bad_inode: add missing i_op initializers Miklos Szeredi
2016-09-12 19:29 ` [PATCH 02/17] ovl: use generic_readlink Miklos Szeredi
2016-09-12 19:29 ` [PATCH 03/17] proc/self: " Miklos Szeredi
2016-09-12 19:29 ` [PATCH 04/17] afs: " Miklos Szeredi
2016-09-12 19:29 ` [PATCH 05/17] bad_inode: " Miklos Szeredi
2016-09-12 19:29 ` [PATCH 06/17] vfs: remove page_readlink() Miklos Szeredi
2016-09-12 19:29 ` [PATCH 07/17] vfs: add is_following_link() helper Miklos Szeredi
2016-09-12 19:29 ` [PATCH 08/17] proc: merge proc_pid_readlink() into proc_pid_get_link() Miklos Szeredi
2016-09-12 19:29 ` [PATCH 09/17] proc: merge proc_ns_readlink() into proc_ns_get_link() Miklos Szeredi
2016-09-12 19:29 ` [PATCH 10/17] nsfs: clean up ns_get_name() interface Miklos Szeredi
2016-09-12 19:29 ` [PATCH 11/17] vfs: replace calling i_op->readlink with vfs_readlink() Miklos Szeredi
2016-09-12 19:29 ` [PATCH 12/17] vfs: remove ".readlink = generic_readlink" assignments Miklos Szeredi
2016-09-12 19:29 ` [PATCH 13/17] vfs: remove unused i_op->readlink Miklos Szeredi
2016-09-12 19:29 ` [PATCH 14/17] vfs: remove unused generic_readlink() Miklos Szeredi
2016-09-12 19:29 ` [PATCH 15/17] vfs: add vfs_get_link() helper Miklos Szeredi
2016-09-12 19:29 ` Miklos Szeredi [this message]
2016-09-12 19:29 ` [PATCH 17/17] ecryptfs: use vfs_get_link() Miklos Szeredi
2016-09-27 3:10 ` [PATCH 00/17] clean up readlinks Al Viro
2016-09-27 9:38 ` Miklos Szeredi
2016-09-28 2:17 ` Al Viro
2016-09-28 14:47 ` Miklos Szeredi
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1473708559-12714-17-git-send-email-mszeredi@redhat.com \
--to=mszeredi@redhat.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=viro@zeniv.linux.org.uk \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).