nfsd: move most of fh_verify to separate function

Move the code that actually parses the filehandle and looks up the
dentry and export to a separate function.  This simplifies the reference
counting a little and moves fh_verify() a little closer to the kernel
ideal of small, minimally-indentended functions.  Clean up a few other
minor style sins along the way.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Cc: Neil Brown <neilb@suse.de>

1 files changed, 123 insertions, 105 deletions

diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c
index 3e6b3f41ee1f..100ae5641162 100644
--- a/fs/nfsd/nfsfh.c
+++ b/fs/nfsd/nfsfh.c
@@ -113,6 +113,124 @@ static __be32 nfsd_setuser_and_check_port(struct svc_rqst *rqstp,
 }
 
 /*
+ * Use the given filehandle to look up the corresponding export and
+ * dentry.  On success, the results are used to set fh_export and
+ * fh_dentry.
+ */
+static __be32 nfsd_set_fh_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp)
+{
+        struct knfsd_fh *fh = &fhp->fh_handle;
+        struct fid *fid = NULL, sfid;
+        struct svc_export *exp;
+        struct dentry *dentry;
+        int fileid_type;
+        int data_left = fh->fh_size/4;
+        __be32 error;
+
+        error = nfserr_stale;
+        if (rqstp->rq_vers > 2)
+                error = nfserr_badhandle;
+        if (rqstp->rq_vers == 4 && fh->fh_size == 0)
+                return nfserr_nofilehandle;
+
+        if (fh->fh_version == 1) {
+                int len;
+
+                if (--data_left < 0)
+                        return error;
+                if (fh->fh_auth_type != 0)
+                        return error;
+                len = key_len(fh->fh_fsid_type) / 4;
+                if (len == 0)
+                        return error;
+                if  (fh->fh_fsid_type == FSID_MAJOR_MINOR) {
+                        /* deprecated, convert to type 3 */
+                        len = key_len(FSID_ENCODE_DEV)/4;
+                        fh->fh_fsid_type = FSID_ENCODE_DEV;
+                        fh->fh_fsid[0] = new_encode_dev(MKDEV(ntohl(fh->fh_fsid[0]), ntohl(fh->fh_fsid[1])));
+                        fh->fh_fsid[1] = fh->fh_fsid[2];
+                }
+                data_left -= len;
+                if (data_left < 0)
+                        return error;
+                exp = rqst_exp_find(rqstp, fh->fh_fsid_type, fh->fh_auth);
+                fid = (struct fid *)(fh->fh_auth + len);
+        } else {
+                __u32 tfh[2];
+                dev_t xdev;
+                ino_t xino;
+
+                if (fh->fh_size != NFS_FHSIZE)
+                        return error;
+                /* assume old filehandle format */
+                xdev = old_decode_dev(fh->ofh_xdev);
+                xino = u32_to_ino_t(fh->ofh_xino);
+                mk_fsid(FSID_DEV, tfh, xdev, xino, 0, NULL);
+                exp = rqst_exp_find(rqstp, FSID_DEV, tfh);
+        }
+
+        error = nfserr_stale;
+        if (PTR_ERR(exp) == -ENOENT)
+                return error;
+
+        if (IS_ERR(exp))
+                return nfserrno(PTR_ERR(exp));
+
+        error = nfsd_setuser_and_check_port(rqstp, exp);
+        if (error)
+                goto out;
+
+        /*
+         * Look up the dentry using the NFS file handle.
+         */
+        error = nfserr_stale;
+        if (rqstp->rq_vers > 2)
+                error = nfserr_badhandle;
+
+        if (fh->fh_version != 1) {
+                sfid.i32.ino = fh->ofh_ino;
+                sfid.i32.gen = fh->ofh_generation;
+                sfid.i32.parent_ino = fh->ofh_dirino;
+                fid = &sfid;
+                data_left = 3;
+                if (fh->ofh_dirino == 0)
+                        fileid_type = FILEID_INO32_GEN;
+                else
+                        fileid_type = FILEID_INO32_GEN_PARENT;
+        } else
+                fileid_type = fh->fh_fileid_type;
+
+        if (fileid_type == FILEID_ROOT)
+                dentry = dget(exp->ex_path.dentry);
+        else {
+                dentry = exportfs_decode_fh(exp->ex_path.mnt, fid,
+                                data_left, fileid_type,
+                                nfsd_acceptable, exp);
+        }
+        if (dentry == NULL)
+                goto out;
+        if (IS_ERR(dentry)) {
+                if (PTR_ERR(dentry) != -EINVAL)
+                        error = nfserrno(PTR_ERR(dentry));
+                goto out;
+        }
+
+        if (S_ISDIR(dentry->d_inode->i_mode) &&
+                        (dentry->d_flags & DCACHE_DISCONNECTED)) {
+                printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %s/%s\n",
+                                dentry->d_parent->d_name.name, dentry->d_name.name);
+        }
+
+        fhp->fh_dentry = dentry;
+        fhp->fh_export = exp;
+        nfsd_nr_verified++;
+        return 0;
+out:
+        exp_put(exp);
+        return error;
+}
+
+/*
  * Perform sanity checks on the dentry in a client's file handle.
  *
  * Note that the file handle dentry may need to be freed even after
@@ -124,115 +242,18 @@ static __be32 nfsd_setuser_and_check_port(struct svc_rqst *rqstp,
 __be32
 fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access)
 {
-        struct knfsd_fh *fh = &fhp->fh_handle;
-        struct svc_export *exp = NULL;
+        struct svc_export *exp;
         struct dentry   *dentry;
-        __be32          error = 0;
+        __be32          error;
 
         dprintk("nfsd: fh_verify(%s)\n", SVCFH_fmt(fhp));
 
         if (!fhp->fh_dentry) {
-                struct fid *fid = NULL, sfid;
-                int fileid_type;
-                int data_left = fh->fh_size/4;
-
-                error = nfserr_stale;
-                if (rqstp->rq_vers > 2)
-                        error = nfserr_badhandle;
-                if (rqstp->rq_vers == 4 && fh->fh_size == 0)
-                        return nfserr_nofilehandle;
-
-                if (fh->fh_version == 1) {
-                        int len;
-                        if (--data_left<0) goto out;
-                        switch (fh->fh_auth_type) {
-                        case 0: break;
-                        default: goto out;
-                        }
-                        len = key_len(fh->fh_fsid_type) / 4;
-                        if (len == 0) goto out;
-                        if  (fh->fh_fsid_type == FSID_MAJOR_MINOR) {
-                                /* deprecated, convert to type 3 */
-                                len = key_len(FSID_ENCODE_DEV)/4;
-                                fh->fh_fsid_type = FSID_ENCODE_DEV;
-                                fh->fh_fsid[0] = new_encode_dev(MKDEV(ntohl(fh->fh_fsid[0]), ntohl(fh->fh_fsid[1])));
-                                fh->fh_fsid[1] = fh->fh_fsid[2];
-                        }
-                        if ((data_left -= len)<0) goto out;
-                        exp = rqst_exp_find(rqstp, fh->fh_fsid_type,
-                                            fh->fh_auth);
-                        fid = (struct fid *)(fh->fh_auth + len);
-                } else {
-                        __u32 tfh[2];
-                        dev_t xdev;
-                        ino_t xino;
-                        if (fh->fh_size != NFS_FHSIZE)
-                                goto out;
-                        /* assume old filehandle format */
-                        xdev = old_decode_dev(fh->ofh_xdev);
-                        xino = u32_to_ino_t(fh->ofh_xino);
-                        mk_fsid(FSID_DEV, tfh, xdev, xino, 0, NULL);
-                        exp = rqst_exp_find(rqstp, FSID_DEV, tfh);
-                }
-
-                error = nfserr_stale;
-                if (PTR_ERR(exp) == -ENOENT)
-                        goto out;
-
-                if (IS_ERR(exp)) {
-                        error = nfserrno(PTR_ERR(exp));
-                        goto out;
-                }
-
-                error = nfsd_setuser_and_check_port(rqstp, exp);
+                error = nfsd_set_fh_dentry(rqstp, fhp);
                 if (error)
                         goto out;
-
-                /*
-                 * Look up the dentry using the NFS file handle.
-                 */
-                error = nfserr_stale;
-                if (rqstp->rq_vers > 2)
-                        error = nfserr_badhandle;
-
-                if (fh->fh_version != 1) {
-                        sfid.i32.ino = fh->ofh_ino;
-                        sfid.i32.gen = fh->ofh_generation;
-                        sfid.i32.parent_ino = fh->ofh_dirino;
-                        fid = &sfid;
-                        data_left = 3;
-                        if (fh->ofh_dirino == 0)
-                                fileid_type = FILEID_INO32_GEN;
-                        else
-                                fileid_type = FILEID_INO32_GEN_PARENT;
-                } else
-                        fileid_type = fh->fh_fileid_type;
-
-                if (fileid_type == FILEID_ROOT)
-                        dentry = dget(exp->ex_path.dentry);
-                else {
-                        dentry = exportfs_decode_fh(exp->ex_path.mnt, fid,
-                                        data_left, fileid_type,
-                                        nfsd_acceptable, exp);
-                }
-                if (dentry == NULL)
-                        goto out;
-                if (IS_ERR(dentry)) {
-                        if (PTR_ERR(dentry) != -EINVAL)
-                                error = nfserrno(PTR_ERR(dentry));
-                        goto out;
-                }
-
-                if (S_ISDIR(dentry->d_inode->i_mode) &&
-                    (dentry->d_flags & DCACHE_DISCONNECTED)) {
-                        printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %s/%s\n",
-                               dentry->d_parent->d_name.name, dentry->d_name.name);
-                }
-
-                fhp->fh_dentry = dentry;
-                fhp->fh_export = exp;
-                nfsd_nr_verified++;
-                cache_get(&exp->h);
+                dentry = fhp->fh_dentry;
+                exp = fhp->fh_export;
         } else {
                 /*
                  * just rechecking permissions
@@ -242,7 +263,6 @@ fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access)
                 dprintk("nfsd: fh_verify - just checking\n");
                 dentry = fhp->fh_dentry;
                 exp = fhp->fh_export;
-                cache_get(&exp->h);
                 /*
                  * Set user creds for this exportpoint; necessary even
                  * in the "just checking" case because this may be a
@@ -281,8 +301,6 @@ fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access)
                         access, ntohl(error));
         }
 out:
-        if (exp && !IS_ERR(exp))
-                exp_put(exp);
         if (error == nfserr_stale)
                 nfsdstats.fh_stale++;
         return error;