autofs4: track uid and gid of last mount requester
Ian Kent [Thu, 16 Oct 2008 05:02:52 +0000 (22:02 -0700)]
Track the uid and gid of the last process to request a mount for on an
autofs dentry.

[akpm@linux-foundation.org: fix tpyo in comment]
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/autofs4/autofs_i.h
fs/autofs4/inode.c
fs/autofs4/waitq.c

index ea024d8..fa76d18 100644 (file)
@@ -63,6 +63,9 @@ struct autofs_info {
        unsigned long last_used;
        atomic_t count;
 
+       uid_t uid;
+       gid_t gid;
+
        mode_t  mode;
        size_t  size;
 
index 7303099..c7e65bb 100644 (file)
@@ -53,6 +53,8 @@ struct autofs_info *autofs4_init_ino(struct autofs_info *ino,
                atomic_set(&ino->count, 0);
        }
 
+       ino->uid = 0;
+       ino->gid = 0;
        ino->mode = mode;
        ino->last_used = jiffies;
 
index 6d87bb1..4b67c2a 100644 (file)
@@ -457,6 +457,40 @@ int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry,
 
        status = wq->status;
 
+       /*
+        * For direct and offset mounts we need to track the requester's
+        * uid and gid in the dentry info struct. This is so it can be
+        * supplied, on request, by the misc device ioctl interface.
+        * This is needed during daemon resatart when reconnecting
+        * to existing, active, autofs mounts. The uid and gid (and
+        * related string values) may be used for macro substitution
+        * in autofs mount maps.
+        */
+       if (!status) {
+               struct autofs_info *ino;
+               struct dentry *de = NULL;
+
+               /* direct mount or browsable map */
+               ino = autofs4_dentry_ino(dentry);
+               if (!ino) {
+                       /* If not lookup actual dentry used */
+                       de = d_lookup(dentry->d_parent, &dentry->d_name);
+                       if (de)
+                               ino = autofs4_dentry_ino(de);
+               }
+
+               /* Set mount requester */
+               if (ino) {
+                       spin_lock(&sbi->fs_lock);
+                       ino->uid = wq->uid;
+                       ino->gid = wq->gid;
+                       spin_unlock(&sbi->fs_lock);
+               }
+
+               if (de)
+                       dput(de);
+       }
+
        /* Are we the last process to need status? */
        mutex_lock(&sbi->wq_mutex);
        if (!--wq->wait_ctr)