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>

diff --git a/fs/nfsd/nfsproc.c b/fs/nfsd/nfsproc.c
index 6722fe5..e921476 100644 (file)
--- a/fs/nfsd/nfsproc.c
+++ b/fs/nfsd/nfsproc.c
@@ -359,8 +359,8 @@ nfsd_proc_create(struct svc_rqst *rqstp, struct nfsd_createargs *argp,
        nfserr = 0;
        if (!inode) {
                /* File doesn't exist. Create it and set attrs */
-               nfserr = nfsd_create(rqstp, dirfhp, argp->name, argp->len,
-                                       attr, type, rdev, newfhp);
+               nfserr = nfsd_create_locked(rqstp, dirfhp, argp->name,
+                                       argp->len, attr, type, rdev, newfhp);
        } else if (type == S_IFREG) {
                dprintk("nfsd:   existing %s, valid=%x, size=%ld\n",
                        argp->name, attr->ia_valid, (long) attr->ia_size);

diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index cf14e39..d21d082 100644 (file)
--- 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
 
 /*

diff --git a/fs/nfsd/vfs.h b/fs/nfsd/vfs.h
index 2d573ec..3cbb1b3 100644 (file)
--- a/fs/nfsd/vfs.h
+++ b/fs/nfsd/vfs.h
@@ -59,6 +59,9 @@ __be32                nfsd4_vfs_fallocate(struct svc_rqst *, struct svc_fh *,
 __be32         nfsd4_clone_file_range(struct file *, u64, struct file *,
                        u64, u64);
 #endif /* CONFIG_NFSD_V4 */
+__be32         nfsd_create_locked(struct svc_rqst *, struct svc_fh *,
+                               char *name, int len, struct iattr *attrs,
+                               int type, dev_t rdev, struct svc_fh *res);
 __be32         nfsd_create(struct svc_rqst *, struct svc_fh *,
                                char *name, int len, struct iattr *attrs,
                                int type, dev_t rdev, struct svc_fh *res);