nfsd: reorganize nfsd_create

There's some odd logic in nfsd_create() that allows it to be called with
the parent directory either locked or unlocked.  The only already-locked
caller is NFSv2's nfsd_proc_create().  It's less confusing to split out
the unlocked case into a separate function which the NFSv2 code can call
directly.

Also fix some comments while we're here.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 56 insertions, 53 deletions

diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index cf14e394a1b0..d21d0827cac4 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1135,16 +1135,9 @@ nfsd_check_ignore_resizing(struct iattr *iap)
                 iap->ia_valid &= ~ATTR_SIZE;
 }
 
-/*
- * Create a file (regular, directory, device, fifo); UNIX sockets 
- * not yet implemented.
- * If the response fh has been verified, the parent directory should
- * already be locked. Note that the parent directory is left locked.
- *
- * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp
- */
+/* The parent directory should already be locked: */
 __be32
-nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
+nfsd_create_locked(struct svc_rqst *rqstp, struct svc_fh *fhp,
                 char *fname, int flen, struct iattr *iap,
                 int type, dev_t rdev, struct svc_fh *resfhp)
 {
@@ -1154,50 +1147,15 @@ nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
         __be32          err2;
         int             host_err;
 
-        err = nfserr_exist;
-        if (isdotent(fname, flen))
-                goto out;
-
-        /*
-         * Even though it is a create, first let's see if we are even allowed
-         * to peek inside the parent
-         */
-        err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);
-        if (err)
-                goto out;
-
         dentry = fhp->fh_dentry;
         dirp = d_inode(dentry);
 
-        /*
-         * Check whether the response file handle has been verified yet.
-         * If it has, the parent directory should already be locked.
-         */
-        if (!resfhp->fh_dentry) {
-                host_err = fh_want_write(fhp);
-                if (host_err)
-                        goto out_nfserr;
-
-                /* called from nfsd_proc_mkdir, or possibly nfsd3_proc_create */
-                fh_lock_nested(fhp, I_MUTEX_PARENT);
-                dchild = lookup_one_len(fname, dentry, flen);
-                host_err = PTR_ERR(dchild);
-                if (IS_ERR(dchild))
-                        goto out_nfserr;
-                err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
-                if (err)
-                        goto out;
-        } else {
-                /* called from nfsd_proc_create */
-                dchild = dget(resfhp->fh_dentry);
-                if (!fhp->fh_locked) {
-                        /* not actually possible */
-                        printk(KERN_ERR
-                                "nfsd_create: parent %pd2 not locked!\n",
+        dchild = dget(resfhp->fh_dentry);
+        if (!fhp->fh_locked) {
+                WARN_ONCE(1, "nfsd_create: parent %pd2 not locked!\n",
                                 dentry);
-                        err = nfserr_io;
-                        goto out;
-                }
+                err = nfserr_io;
+                goto out;
         }
         /*
          * Make sure the child dentry is still negative ...
@@ -1225,9 +1183,6 @@ nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
                 goto out;
         }
 
-        /*
-         * Get the dir op function pointer.
-         */
         err = 0;
         host_err = 0;
         switch (type) {
@@ -1254,7 +1209,7 @@ nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
         /*
          * nfsd_create_setattr already committed the child.  Transactional
          * filesystems had a chance to commit changes for both parent and
-         * child * simultaneously making the following commit_metadata a
+         * child simultaneously making the following commit_metadata a
          * noop.
          */
         err2 = nfserrno(commit_metadata(fhp));
@@ -1275,6 +1230,54 @@ out_nfserr:
         goto out;
 }
 
+/*
+ * Create a filesystem object (regular, directory, special).
+ * Note that the parent directory is left locked.
+ *
+ * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp
+ */
+__be32
+nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
+                char *fname, int flen, struct iattr *iap,
+                int type, dev_t rdev, struct svc_fh *resfhp)
+{
+        struct dentry   *dentry, *dchild = NULL;
+        struct inode    *dirp;
+        __be32          err;
+        int             host_err;
+
+        if (isdotent(fname, flen))
+                return nfserr_exist;
+
+        /*
+         * Even though it is a create, first let's see if we are even allowed
+         * to peek inside the parent
+         */
+        err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);
+        if (err)
+                return err;
+
+        dentry = fhp->fh_dentry;
+        dirp = d_inode(dentry);
+
+        host_err = fh_want_write(fhp);
+        if (host_err)
+                return nfserrno(host_err);
+
+        fh_lock_nested(fhp, I_MUTEX_PARENT);
+        dchild = lookup_one_len(fname, dentry, flen);
+        host_err = PTR_ERR(dchild);
+        if (IS_ERR(dchild))
+                return nfserrno(host_err);
+        err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
+        if (err) {
+                dput(dchild);
+                return err;
+        }
+        return nfsd_create_locked(rqstp, fhp, fname, flen, iap, type,
+                                        rdev, resfhp);
+}
+
 #ifdef CONFIG_NFSD_V3
 
 /*