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>

diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c
index 3e6b3f4..100ae56 100644 (file)
--- 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;