1 files changed, 73 insertions, 70 deletions

diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index a293f0273263..8715d194561a 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1,7 +1,5 @@
 #define MSNFS   /* HACK HACK */
 /*
- * linux/fs/nfsd/vfs.c
- *
  * File operations used by nfsd. Some of these have been ripped from
  * other parts of the kernel because they weren't exported, others
  * are partial duplicates with added or changed functionality.
@@ -16,48 +14,31 @@
  * Zerocpy NFS support (C) 2002 Hirokazu Takahashi <taka@valinux.co.jp>
  */
 
-#include <linux/string.h>
-#include <linux/time.h>
-#include <linux/errno.h>
 #include <linux/fs.h>
 #include <linux/file.h>
-#include <linux/mount.h>
-#include <linux/major.h>
 #include <linux/splice.h>
-#include <linux/proc_fs.h>
-#include <linux/stat.h>
 #include <linux/fcntl.h>
-#include <linux/net.h>
-#include <linux/unistd.h>
-#include <linux/slab.h>
-#include <linux/pagemap.h>
-#include <linux/in.h>
-#include <linux/module.h>
 #include <linux/namei.h>
-#include <linux/vfs.h>
 #include <linux/delay.h>
-#include <linux/sunrpc/svc.h>
-#include <linux/nfsd/nfsd.h>
-#ifdef CONFIG_NFSD_V3
-#include <linux/nfs3.h>
-#include <linux/nfsd/xdr3.h>
-#endif /* CONFIG_NFSD_V3 */
-#include <linux/nfsd/nfsfh.h>
 #include <linux/quotaops.h>
 #include <linux/fsnotify.h>
-#include <linux/posix_acl.h>
 #include <linux/posix_acl_xattr.h>
 #include <linux/xattr.h>
+#include <linux/jhash.h>
+#include <linux/ima.h>
+#include <asm/uaccess.h>
+
+#ifdef CONFIG_NFSD_V3
+#include "xdr3.h"
+#endif /* CONFIG_NFSD_V3 */
+
 #ifdef CONFIG_NFSD_V4
-#include <linux/nfs4.h>
 #include <linux/nfs4_acl.h>
 #include <linux/nfsd_idmap.h>
-#include <linux/security.h>
 #endif /* CONFIG_NFSD_V4 */
-#include <linux/jhash.h>
-#include <linux/ima.h>
 
-#include <asm/uaccess.h>
+#include "nfsd.h"
+#include "vfs.h"
 
 #define NFSDDBG_FACILITY                NFSDDBG_FILEOP
 
@@ -89,12 +70,6 @@ struct raparm_hbucket {
 #define RAPARM_HASH_MASK        (RAPARM_HASH_SIZE-1)
 static struct raparm_hbucket    raparm_hash[RAPARM_HASH_SIZE];
 
-static inline int
-nfsd_v4client(struct svc_rqst *rq)
-{
-    return rq->rq_prog == NFS_PROGRAM && rq->rq_vers == 4;
-}
-
 /* 
  * Called from nfsd_lookup and encode_dirent. Check if we have crossed 
  * a mount point.
@@ -116,8 +91,16 @@ nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp,
 
         exp2 = rqst_exp_get_by_name(rqstp, &path);
         if (IS_ERR(exp2)) {
-                if (PTR_ERR(exp2) != -ENOENT)
-                        err = PTR_ERR(exp2);
+                err = PTR_ERR(exp2);
+                /*
+                 * We normally allow NFS clients to continue
+                 * "underneath" a mountpoint that is not exported.
+                 * The exception is V4ROOT, where no traversal is ever
+                 * allowed without an explicit export of the new
+                 * directory.
+                 */
+                if (err == -ENOENT && !(exp->ex_flags & NFSEXP_V4ROOT))
+                        err = 0;
                 path_put(&path);
                 goto out;
         }
@@ -141,6 +124,53 @@ out:
         return err;
 }
 
+static void follow_to_parent(struct path *path)
+{
+        struct dentry *dp;
+
+        while (path->dentry == path->mnt->mnt_root && follow_up(path))
+                ;
+        dp = dget_parent(path->dentry);
+        dput(path->dentry);
+        path->dentry = dp;
+}
+
+static int nfsd_lookup_parent(struct svc_rqst *rqstp, struct dentry *dparent, struct svc_export **exp, struct dentry **dentryp)
+{
+        struct svc_export *exp2;
+        struct path path = {.mnt = mntget((*exp)->ex_path.mnt),
+                            .dentry = dget(dparent)};
+
+        follow_to_parent(&path);
+
+        exp2 = rqst_exp_parent(rqstp, &path);
+        if (PTR_ERR(exp2) == -ENOENT) {
+                *dentryp = dget(dparent);
+        } else if (IS_ERR(exp2)) {
+                path_put(&path);
+                return PTR_ERR(exp2);
+        } else {
+                *dentryp = dget(path.dentry);
+                exp_put(*exp);
+                *exp = exp2;
+        }
+        path_put(&path);
+        return 0;
+}
+
+/*
+ * For nfsd purposes, we treat V4ROOT exports as though there was an
+ * export at *every* directory.
+ */
+int nfsd_mountpoint(struct dentry *dentry, struct svc_export *exp)
+{
+        if (d_mountpoint(dentry))
+                return 1;
+        if (!(exp->ex_flags & NFSEXP_V4ROOT))
+                return 0;
+        return dentry->d_inode != NULL;
+}
+
 __be32
 nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp,
                    const char *name, unsigned int len,
@@ -169,35 +199,13 @@ nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp,
                         dentry = dget(dparent);
                 else if (dparent != exp->ex_path.dentry)
                         dentry = dget_parent(dparent);
-                else if (!EX_NOHIDE(exp))
+                else if (!EX_NOHIDE(exp) && !nfsd_v4client(rqstp))
                         dentry = dget(dparent); /* .. == . just like at / */
                 else {
                         /* checking mountpoint crossing is very different when stepping up */
-                        struct svc_export *exp2 = NULL;
-                        struct dentry *dp;
-                        struct path path = {.mnt = mntget(exp->ex_path.mnt),
-                                            .dentry = dget(dparent)};
-
-                        while (path.dentry == path.mnt->mnt_root &&
-                               follow_up(&path))
-                                ;
-                        dp = dget_parent(path.dentry);
-                        dput(path.dentry);
-                        path.dentry = dp;
-
-                        exp2 = rqst_exp_parent(rqstp, &path);
-                        if (PTR_ERR(exp2) == -ENOENT) {
-                                dentry = dget(dparent);
-                        } else if (IS_ERR(exp2)) {
-                                host_err = PTR_ERR(exp2);
-                                path_put(&path);
+                        host_err = nfsd_lookup_parent(rqstp, dparent, &exp, &dentry);
+                        if (host_err)
                                 goto out_nfserr;
-                        } else {
-                                dentry = dget(path.dentry);
-                                exp_put(exp);
-                                exp = exp2;
-                        }
-                        path_put(&path);
                 }
         } else {
                 fh_lock(fhp);
@@ -208,7 +216,7 @@ nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp,
                 /*
                  * check if we have crossed a mount point ...
                  */
-                if (d_mountpoint(dentry)) {
+                if (nfsd_mountpoint(dentry, exp)) {
                         if ((host_err = nfsd_cross_mnt(rqstp, &dentry, &exp))) {
                                 dput(dentry);
                                 goto out_nfserr;
@@ -745,7 +753,7 @@ nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
         if (IS_ERR(*filp))
                 host_err = PTR_ERR(*filp);
         else
-                ima_counts_get(*filp);
+                host_err = ima_file_check(*filp, access);
 out_nfserr:
         err = nfserrno(host_err);
 out:
@@ -774,12 +782,9 @@ static inline int nfsd_dosync(struct file *filp, struct dentry *dp,
         int (*fsync) (struct file *, struct dentry *, int);
         int err;
 
-        err = filemap_fdatawrite(inode->i_mapping);
+        err = filemap_write_and_wait(inode->i_mapping);
         if (err == 0 && fop && (fsync = fop->fsync))
                 err = fsync(filp, dp, 0);
-        if (err == 0)
-                err = filemap_fdatawait(inode->i_mapping);
-
         return err;
 }
 
@@ -2124,8 +2129,6 @@ nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
          */
         path.mnt = exp->ex_path.mnt;
         path.dentry = dentry;
-        err = ima_path_check(&path, acc & (MAY_READ | MAY_WRITE | MAY_EXEC),
-                             IMA_COUNT_LEAVE);
 nfsd_out:
         return err? nfserrno(err) : 0;
 }