Solaris: lookup "" like "."

At least on some versions of solaris, we can get passed an empty
string to afs_lookup, if the root directory is in AFS (e.g. after a
chroot). Interpret this as the same as looking up the "." entry;
otherwise we return ENOENT, implying that the "/" directory does not
exist, even if its subdirectories do.

FIXES 127356

Change-Id: I84283e78fbf33b946afaf3c80ef4a1a679e8fc93
Reviewed-on: http://gerrit.openafs.org/2096
Tested-by: Andrew Deason <adeason@sinenomine.net>
Reviewed-by: Simon Wilkinson <sxw@inf.ed.ac.uk>
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>

diff --git a/src/afs/VNOPS/afs_vnop_lookup.c b/src/afs/VNOPS/afs_vnop_lookup.c
index 630b64390951505bf38d2758dba257203a6b3250..82e023405699a9f456c54b66504af8319ce1c1aa 100644 (file)
--- a/src/afs/VNOPS/afs_vnop_lookup.c
+++ b/src/afs/VNOPS/afs_vnop_lookup.c
@@ -1288,6 +1288,23 @@ afs_DoBulkStat(struct vcache *adp, long dirCookie, struct vrequest *areqp)
 /* was: (AFS_DEC_ENV) || defined(AFS_OSF30_ENV) || defined(AFS_NCR_ENV) */
 static int AFSDOBULK = 1;
 
+static_inline int
+osi_lookup_isdot(const char *aname)
+{
+#ifdef AFS_SUN5_ENV
+    if (!aname[0]) {
+       /* in Solaris, we can get passed "" as a path component if we are the
+        * root directory, e.g. after a call to chroot. It is equivalent to
+        * looking up "." */
+       return 1;
+    }
+#endif /* AFS_SUN5_ENV */
+    if (aname[0] == '.' && !aname[1]) {
+       return 1;
+    }
+    return 0;
+}
+
 int
 #if defined(AFS_SUN5_ENV) || defined(AFS_SGI_ENV)
 afs_lookup(OSI_VC_DECL(adp), char *aname, struct vcache **avcp, struct pathname *pnp, int flags, struct vnode *rdir, afs_ucred_t *acred)
@@ -1415,7 +1432,7 @@ afs_lookup(OSI_VC_DECL(adp), char *aname, struct vcache **avcp, afs_ucred_t *acr
      * I'm not fiddling with the LRUQ here, either, perhaps I should, or else 
      * invent a lightweight version of GetVCache.
      */
-    if (aname[0] == '.' && !aname[1]) {        /* special case */
+    if (osi_lookup_isdot(aname)) {     /* special case */
        ObtainReadLock(&afs_xvcache);
        osi_vnhold(adp, 0);
        ReleaseReadLock(&afs_xvcache);