Merge branch 'for-2.6.37' of git://linux-nfs.org/~bfields/linux

* 'for-2.6.37' of git://linux-nfs.org/~bfields/linux:
  nfsd: Fix possible BUG_ON firing in set_change_info
  sunrpc: prevent use-after-free on clearing XPT_BUSY

3 files changed, 22 insertions, 14 deletions

diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c
index 2a533a0af2a9..7e84a852cdae 100644
--- a/fs/nfsd/nfs3xdr.c
+++ b/fs/nfsd/nfs3xdr.c
@@ -260,9 +260,11 @@ void fill_post_wcc(struct svc_fh *fhp)
         err = vfs_getattr(fhp->fh_export->ex_path.mnt, fhp->fh_dentry,
                         &fhp->fh_post_attr);
         fhp->fh_post_change = fhp->fh_dentry->d_inode->i_version;
-        if (err)
+        if (err) {
                 fhp->fh_post_saved = 0;
-        else
+                /* Grab the ctime anyway - set_change_info might use it */
+                fhp->fh_post_attr.ctime = fhp->fh_dentry->d_inode->i_ctime;
+        } else
                 fhp->fh_post_saved = 1;
 }
 
diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h
index 4d476ff08ae6..60fce3dc5cb5 100644
--- a/fs/nfsd/xdr4.h
+++ b/fs/nfsd/xdr4.h
@@ -484,18 +484,17 @@ static inline bool nfsd4_not_cached(struct nfsd4_compoundres *resp)
 static inline void
 set_change_info(struct nfsd4_change_info *cinfo, struct svc_fh *fhp)
 {
-        BUG_ON(!fhp->fh_pre_saved || !fhp->fh_post_saved);
-        cinfo->atomic = 1;
+        BUG_ON(!fhp->fh_pre_saved);
+        cinfo->atomic = fhp->fh_post_saved;
         cinfo->change_supported = IS_I_VERSION(fhp->fh_dentry->d_inode);
-        if (cinfo->change_supported) {
-                cinfo->before_change = fhp->fh_pre_change;
-                cinfo->after_change = fhp->fh_post_change;
-        } else {
-                cinfo->before_ctime_sec = fhp->fh_pre_ctime.tv_sec;
-                cinfo->before_ctime_nsec = fhp->fh_pre_ctime.tv_nsec;
-                cinfo->after_ctime_sec = fhp->fh_post_attr.ctime.tv_sec;
-                cinfo->after_ctime_nsec = fhp->fh_post_attr.ctime.tv_nsec;
-        }
+
+        cinfo->before_change = fhp->fh_pre_change;
+        cinfo->after_change = fhp->fh_post_change;
+        cinfo->before_ctime_sec = fhp->fh_pre_ctime.tv_sec;
+        cinfo->before_ctime_nsec = fhp->fh_pre_ctime.tv_nsec;
+        cinfo->after_ctime_sec = fhp->fh_post_attr.ctime.tv_sec;
+        cinfo->after_ctime_nsec = fhp->fh_post_attr.ctime.tv_nsec;
+
 }
 
 int nfs4svc_encode_voidres(struct svc_rqst *, __be32 *, void *);
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index ea2ff78dcf7b..3f2c5559ca1a 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -212,6 +212,7 @@ int svc_create_xprt(struct svc_serv *serv, const char *xprt_name,
         spin_lock(&svc_xprt_class_lock);
         list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) {
                 struct svc_xprt *newxprt;
+                unsigned short newport;
 
                 if (strcmp(xprt_name, xcl->xcl_name))
                         continue;
@@ -230,8 +231,9 @@ int svc_create_xprt(struct svc_serv *serv, const char *xprt_name,
                 spin_lock_bh(&serv->sv_lock);
                 list_add(&newxprt->xpt_list, &serv->sv_permsocks);
                 spin_unlock_bh(&serv->sv_lock);
+                newport = svc_xprt_local_port(newxprt);
                 clear_bit(XPT_BUSY, &newxprt->xpt_flags);
-                return svc_xprt_local_port(newxprt);
+                return newport;
         }
  err:
         spin_unlock(&svc_xprt_class_lock);
@@ -425,8 +427,13 @@ void svc_xprt_received(struct svc_xprt *xprt)
 {
         BUG_ON(!test_bit(XPT_BUSY, &xprt->xpt_flags));
         xprt->xpt_pool = NULL;
+        /* As soon as we clear busy, the xprt could be closed and
+         * 'put', so we need a reference to call svc_xprt_enqueue with:
+         */
+        svc_xprt_get(xprt);
         clear_bit(XPT_BUSY, &xprt->xpt_flags);
         svc_xprt_enqueue(xprt);
+        svc_xprt_put(xprt);
 }
 EXPORT_SYMBOL_GPL(svc_xprt_received);