Re: [PATCH] [V2] fs/9p: TREADLINK bugfix

From: M. Mohan Kumar
Date: Thu Jan 06 2011 - 00:55:45 EST


Thanks Aneesh, I will be posting the patch with addressing your comments.

On Thursday 06 January 2011 10:50:26 am Aneesh Kumar K. V wrote:
> On Wed, 5 Jan 2011 22:19:56 +0530, "M. Mohan Kumar" <mohan@xxxxxxxxxx>
wrote:
> > Remove v9fs_vfs_readlink_dotl function and use generic_readlink. Update
> > v9fs_vfs_follow_link_dotl function to accommodate this change
> >
> > Signed-off-by: M. Mohan Kumar <mohan@xxxxxxxxxx>
> > Reported-by: Dr. David Alan Gilbert <linux@xxxxxxxxxxx>
> > ---
> > Changes from previous version:
> > * Use __getname in v9fs_vfs_follow_link_dotl
> > * Remove v9fs_vfs_readlink_dotl function
> >
> > fs/9p/vfs_inode.c | 53
> > +++++++++++++++++------------------------------------ 1 files changed,
> > 17 insertions(+), 36 deletions(-)
> >
> > diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
> > index 2ce3668..7e613e8 100644
> > --- a/fs/9p/vfs_inode.c
> > +++ b/fs/9p/vfs_inode.c
> >
> > @@ -1994,30 +1994,6 @@ error:
> > return err;
> >
> > }
> >
> > -static int
> > -v9fs_vfs_readlink_dotl(struct dentry *dentry, char *buffer, int buflen)
> > -{
> > - int retval;
> > - struct p9_fid *fid;
> > - char *target = NULL;
> > -
> > - P9_DPRINTK(P9_DEBUG_VFS, " %s\n", dentry->d_name.name);
> > - retval = -EPERM;
> > - fid = v9fs_fid_lookup(dentry);
> > - if (IS_ERR(fid))
> > - return PTR_ERR(fid);
> > -
> > - retval = p9_client_readlink(fid, &target);
> > - if (retval < 0)
> > - return retval;
> > -
> > - strncpy(buffer, target, buflen);
> > - P9_DPRINTK(P9_DEBUG_VFS, "%s -> %s\n", dentry->d_name.name, buffer);
> > -
> > - retval = strnlen(buffer, buflen);
> > - return retval;
> > -}
> > -
> >
> > /**
> >
> > * v9fs_vfs_follow_link_dotl - follow a symlink path
> > * @dentry: dentry for symlink
> >
> > @@ -2028,23 +2004,28 @@ v9fs_vfs_readlink_dotl(struct dentry *dentry,
> > char *buffer, int buflen)
> >
> > static void *
> > v9fs_vfs_follow_link_dotl(struct dentry *dentry, struct nameidata *nd)
> > {
> >
> > - int len = 0;
> > + int retval;
> > + struct p9_fid *fid;
> >
> > char *link = __getname();
> >
> > + char *target;
> >
> > - P9_DPRINTK(P9_DEBUG_VFS, "%s n", dentry->d_name.name);
> > + P9_DPRINTK(P9_DEBUG_VFS, "%s\n", dentry->d_name.name);
> >
> > if (!link)
> >
> > - link = ERR_PTR(-ENOMEM);
> > - else {
> > - len = v9fs_vfs_readlink_dotl(dentry, link, PATH_MAX);
> > - if (len < 0) {
> > - __putname(link);
> > - link = ERR_PTR(len);
> > - } else
> > - link[min(len, PATH_MAX-1)] = 0;
> > + return NULL;
> > + fid = v9fs_fid_lookup(dentry);
> > + if (IS_ERR(fid))
> > + return fid;
>
> need to do a __putname(link) and do a nd_set_link(nd, ERR_PTR(fid))
>
> > + retval = p9_client_readlink(fid, &target);
> > + if (retval < 0) {
> > + __putname(link);
> > + kfree(target);
>
> On error target should not be allocated right ? So why kfree ?
>
> > + return NULL;
> >
> > }
> >
> > - nd_set_link(nd, link);
> >
> > + strcpy(link, target);
> > + nd_set_link(nd, link);
> > + kfree(target);
> >
> > return NULL;
> >
> > }
>
> -aneesh

----
M. Mohan Kumar
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