[PATCH v2 06/10] vfs: turn do_path_lookup into wrapper around getname_info variant

Jeff Layton
2012-09-20T14:23:36Z

...and make the user_path callers use that variant instead.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
---
fs/namei.c | 30 +++++++++++++++++++++++-------
1 file changed, 23 insertions(+), 7 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 01a2dd18..8fe643e 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1993,20 +1993,30 @@ static int path_lookupat(int dfd, const char *name,
return err;
}

-static int do_path_lookup(int dfd, const char *name,
+static int ginfo_lookup(int dfd, struct getname_info *ginfo,
unsigned int flags, struct nameidata *nd)
{
- int retval = path_lookupat(dfd, name, flags | LOOKUP_RCU, nd);
+ int retval = path_lookupat(dfd, ginfo->name, flags | LOOKUP_RCU, nd);
if (unlikely(retval == -ECHILD))
- retval = path_lookupat(dfd, name, flags, nd);
+ retval = path_lookupat(dfd, ginfo->name, flags, nd);
if (unlikely(retval == -ESTALE))
- retval = path_lookupat(dfd, name, flags | LOOKUP_REVAL, nd);
+ retval = path_lookupat(dfd, ginfo->name,
+ flags | LOOKUP_REVAL, nd);

if (likely(!retval))
- audit_inode(name, nd->path.dentry, flags & LOOKUP_PARENT);
+ audit_inode(ginfo->name, nd->path.dentry,
+ flags & LOOKUP_PARENT);
return retval;
}

+static int do_path_lookup(int dfd, const char *name,
+ unsigned int flags, struct nameidata *nd)
+{
+ struct getname_info ginfo = { .name = name };
+
+ return ginfo_lookup(dfd, &ginfo, flags, nd);
+}
+
/* does lookup, returns the object with parent locked */
struct dentry *kern_path_locked(const char *name, struct path *path)
{
@@ -2130,7 +2140,7 @@ int user_path_at_empty(int dfd, const char __user *name, unsigned flags,

BUG_ON(flags & LOOKUP_PARENT);

- err = do_path_lookup(dfd, tmp->name, flags, &nd);
+ err = ginfo_lookup(dfd, tmp, flags, &nd);
putname(tmp);
if (!err)
*path = nd.path;
@@ -2144,6 +2154,12 @@ int user_path_at(int dfd, const char __user *name, unsigned flags,
return user_path_at_empty(dfd, name, flags, path, NULL);
}

+/*
+ * NB: most callers don't do anything directly with the reference to the
+ * to ginfo, but the nd->last pointer points into the name string
+ * allocated by getinfo. So we must hold the reference to it until all
+ * path-walking is complete.
+ */
static struct getname_info *
user_path_parent(int dfd, const char __user *path, struct nameidata *nd)
{
@@ -2153,7 +2169,7 @@ user_path_parent(int dfd, const char __user *path, struct nameidata *nd)
if (IS_ERR(s))
return s;

- error = do_path_lookup(dfd, s->name, LOOKUP_PARENT, nd);
+ error = ginfo_lookup(dfd, s, LOOKUP_PARENT, nd);
if (error) {
putname(s);
return ERR_PTR(error);
--
1.7.11.4