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>

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>
J. Bruce Fields
1 parent c3bb257d2d
Showing 1 changed file with 123 additions and 105 deletions Side-by-side Diff
fs/nfsd/nfsfh.c
@@ -113,6 +113,124 @@
 }
  
 /*
+ * 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 @@
 __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 @@
 		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 @@
 			access, ntohl(error));
 	}
 out:
-	if (exp && !IS_ERR(exp))
-		exp_put(exp);
 	if (error == nfserr_stale)
 		nfsdstats.fh_stale++;
 	return error;
...	...	@@ -113,6 +113,124 @@
113	113	}
114	114
115	115	/*
	116	+ * Use the given filehandle to look up the corresponding export and
	117	+ * dentry. On success, the results are used to set fh_export and
	118	+ * fh_dentry.
	119	+ */
	120	+static __be32 nfsd_set_fh_dentry(struct svc_rqst rqstp, struct svc_fh fhp)
	121	+{
	122	+ struct knfsd_fh *fh = &fhp->fh_handle;
	123	+ struct fid *fid = NULL, sfid;
	124	+ struct svc_export *exp;
	125	+ struct dentry *dentry;
	126	+ int fileid_type;
	127	+ int data_left = fh->fh_size/4;
	128	+ __be32 error;
	129	+
	130	+ error = nfserr_stale;
	131	+ if (rqstp->rq_vers > 2)
	132	+ error = nfserr_badhandle;
	133	+ if (rqstp->rq_vers == 4 && fh->fh_size == 0)
	134	+ return nfserr_nofilehandle;
	135	+
	136	+ if (fh->fh_version == 1) {
	137	+ int len;
	138	+
	139	+ if (--data_left < 0)
	140	+ return error;
	141	+ if (fh->fh_auth_type != 0)
	142	+ return error;
	143	+ len = key_len(fh->fh_fsid_type) / 4;
	144	+ if (len == 0)
	145	+ return error;
	146	+ if (fh->fh_fsid_type == FSID_MAJOR_MINOR) {
	147	+ /* deprecated, convert to type 3 */
	148	+ len = key_len(FSID_ENCODE_DEV)/4;
	149	+ fh->fh_fsid_type = FSID_ENCODE_DEV;
	150	+ fh->fh_fsid[0] = new_encode_dev(MKDEV(ntohl(fh->fh_fsid[0]), ntohl(fh->fh_fsid[1])));
	151	+ fh->fh_fsid[1] = fh->fh_fsid[2];
	152	+ }
	153	+ data_left -= len;
	154	+ if (data_left < 0)
	155	+ return error;
	156	+ exp = rqst_exp_find(rqstp, fh->fh_fsid_type, fh->fh_auth);
	157	+ fid = (struct fid *)(fh->fh_auth + len);
	158	+ } else {
	159	+ __u32 tfh[2];
	160	+ dev_t xdev;
	161	+ ino_t xino;
	162	+
	163	+ if (fh->fh_size != NFS_FHSIZE)
	164	+ return error;
	165	+ /* assume old filehandle format */
	166	+ xdev = old_decode_dev(fh->ofh_xdev);
	167	+ xino = u32_to_ino_t(fh->ofh_xino);
	168	+ mk_fsid(FSID_DEV, tfh, xdev, xino, 0, NULL);
	169	+ exp = rqst_exp_find(rqstp, FSID_DEV, tfh);
	170	+ }
	171	+
	172	+ error = nfserr_stale;
	173	+ if (PTR_ERR(exp) == -ENOENT)
	174	+ return error;
	175	+
	176	+ if (IS_ERR(exp))
	177	+ return nfserrno(PTR_ERR(exp));
	178	+
	179	+ error = nfsd_setuser_and_check_port(rqstp, exp);
	180	+ if (error)
	181	+ goto out;
	182	+
	183	+ /*
	184	+ * Look up the dentry using the NFS file handle.
	185	+ */
	186	+ error = nfserr_stale;
	187	+ if (rqstp->rq_vers > 2)
	188	+ error = nfserr_badhandle;
	189	+
	190	+ if (fh->fh_version != 1) {
	191	+ sfid.i32.ino = fh->ofh_ino;
	192	+ sfid.i32.gen = fh->ofh_generation;
	193	+ sfid.i32.parent_ino = fh->ofh_dirino;
	194	+ fid = &sfid;
	195	+ data_left = 3;
	196	+ if (fh->ofh_dirino == 0)
	197	+ fileid_type = FILEID_INO32_GEN;
	198	+ else
	199	+ fileid_type = FILEID_INO32_GEN_PARENT;
	200	+ } else
	201	+ fileid_type = fh->fh_fileid_type;
	202	+
	203	+ if (fileid_type == FILEID_ROOT)
	204	+ dentry = dget(exp->ex_path.dentry);
	205	+ else {
	206	+ dentry = exportfs_decode_fh(exp->ex_path.mnt, fid,
	207	+ data_left, fileid_type,
	208	+ nfsd_acceptable, exp);
	209	+ }
	210	+ if (dentry == NULL)
	211	+ goto out;
	212	+ if (IS_ERR(dentry)) {
	213	+ if (PTR_ERR(dentry) != -EINVAL)
	214	+ error = nfserrno(PTR_ERR(dentry));
	215	+ goto out;
	216	+ }
	217	+
	218	+ if (S_ISDIR(dentry->d_inode->i_mode) &&
	219	+ (dentry->d_flags & DCACHE_DISCONNECTED)) {
	220	+ printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %s/%s\n",
	221	+ dentry->d_parent->d_name.name, dentry->d_name.name);
	222	+ }
	223	+
	224	+ fhp->fh_dentry = dentry;
	225	+ fhp->fh_export = exp;
	226	+ nfsd_nr_verified++;
	227	+ return 0;
	228	+out:
	229	+ exp_put(exp);
	230	+ return error;
	231	+}
	232	+
	233	+/*
116	234	* Perform sanity checks on the dentry in a client's file handle.
117	235	*
118	236	* Note that the file handle dentry may need to be freed even after
119	237
120	238
121	239
...	...	@@ -124,115 +242,18 @@
124	242	__be32
125	243	fh_verify(struct svc_rqst rqstp, struct svc_fh fhp, int type, int access)
126	244	{
127		- struct knfsd_fh *fh = &fhp->fh_handle;
128		- struct svc_export *exp = NULL;
	245	+ struct svc_export *exp;
129	246	struct dentry *dentry;
130		- __be32 error = 0;
	247	+ __be32 error;
131	248
132	249	dprintk("nfsd: fh_verify(%s)\n", SVCFH_fmt(fhp));
133	250
134	251	if (!fhp->fh_dentry) {
135		- struct fid *fid = NULL, sfid;
136		- int fileid_type;
137		- int data_left = fh->fh_size/4;
138		-
139		- error = nfserr_stale;
140		- if (rqstp->rq_vers > 2)
141		- error = nfserr_badhandle;
142		- if (rqstp->rq_vers == 4 && fh->fh_size == 0)
143		- return nfserr_nofilehandle;
144		-
145		- if (fh->fh_version == 1) {
146		- int len;
147		- if (--data_left<0) goto out;
148		- switch (fh->fh_auth_type) {
149		- case 0: break;
150		- default: goto out;
151		- }
152		- len = key_len(fh->fh_fsid_type) / 4;
153		- if (len == 0) goto out;
154		- if (fh->fh_fsid_type == FSID_MAJOR_MINOR) {
155		- /* deprecated, convert to type 3 */
156		- len = key_len(FSID_ENCODE_DEV)/4;
157		- fh->fh_fsid_type = FSID_ENCODE_DEV;
158		- fh->fh_fsid[0] = new_encode_dev(MKDEV(ntohl(fh->fh_fsid[0]), ntohl(fh->fh_fsid[1])));
159		- fh->fh_fsid[1] = fh->fh_fsid[2];
160		- }
161		- if ((data_left -= len)<0) goto out;
162		- exp = rqst_exp_find(rqstp, fh->fh_fsid_type,
163		- fh->fh_auth);
164		- fid = (struct fid *)(fh->fh_auth + len);
165		- } else {
166		- __u32 tfh[2];
167		- dev_t xdev;
168		- ino_t xino;
169		- if (fh->fh_size != NFS_FHSIZE)
170		- goto out;
171		- /* assume old filehandle format */
172		- xdev = old_decode_dev(fh->ofh_xdev);
173		- xino = u32_to_ino_t(fh->ofh_xino);
174		- mk_fsid(FSID_DEV, tfh, xdev, xino, 0, NULL);
175		- exp = rqst_exp_find(rqstp, FSID_DEV, tfh);
176		- }
177		-
178		- error = nfserr_stale;
179		- if (PTR_ERR(exp) == -ENOENT)
180		- goto out;
181		-
182		- if (IS_ERR(exp)) {
183		- error = nfserrno(PTR_ERR(exp));
184		- goto out;
185		- }
186		-
187		- error = nfsd_setuser_and_check_port(rqstp, exp);
	252	+ error = nfsd_set_fh_dentry(rqstp, fhp);
188	253	if (error)
189	254	goto out;
190		-
191		- /*
192		- * Look up the dentry using the NFS file handle.
193		- */
194		- error = nfserr_stale;
195		- if (rqstp->rq_vers > 2)
196		- error = nfserr_badhandle;
197		-
198		- if (fh->fh_version != 1) {
199		- sfid.i32.ino = fh->ofh_ino;
200		- sfid.i32.gen = fh->ofh_generation;
201		- sfid.i32.parent_ino = fh->ofh_dirino;
202		- fid = &sfid;
203		- data_left = 3;
204		- if (fh->ofh_dirino == 0)
205		- fileid_type = FILEID_INO32_GEN;
206		- else
207		- fileid_type = FILEID_INO32_GEN_PARENT;
208		- } else
209		- fileid_type = fh->fh_fileid_type;
210		-
211		- if (fileid_type == FILEID_ROOT)
212		- dentry = dget(exp->ex_path.dentry);
213		- else {
214		- dentry = exportfs_decode_fh(exp->ex_path.mnt, fid,
215		- data_left, fileid_type,
216		- nfsd_acceptable, exp);
217		- }
218		- if (dentry == NULL)
219		- goto out;
220		- if (IS_ERR(dentry)) {
221		- if (PTR_ERR(dentry) != -EINVAL)
222		- error = nfserrno(PTR_ERR(dentry));
223		- goto out;
224		- }
225		-
226		- if (S_ISDIR(dentry->d_inode->i_mode) &&
227		- (dentry->d_flags & DCACHE_DISCONNECTED)) {
228		- printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %s/%s\n",
229		- dentry->d_parent->d_name.name, dentry->d_name.name);
230		- }
231		-
232		- fhp->fh_dentry = dentry;
233		- fhp->fh_export = exp;
234		- nfsd_nr_verified++;
235		- cache_get(&exp->h);
	255	+ dentry = fhp->fh_dentry;
	256	+ exp = fhp->fh_export;
236	257	} else {
237	258	/*
238	259	* just rechecking permissions
...	...	@@ -242,7 +263,6 @@
242	263	dprintk("nfsd: fh_verify - just checking\n");
243	264	dentry = fhp->fh_dentry;
244	265	exp = fhp->fh_export;
245		- cache_get(&exp->h);
246	266	/*
247	267	* Set user creds for this exportpoint; necessary even
248	268	* in the "just checking" case because this may be a
...	...	@@ -281,8 +301,6 @@
281	301	access, ntohl(error));
282	302	}
283	303	out:
284		- if (exp && !IS_ERR(exp))
285		- exp_put(exp);
286	304	if (error == nfserr_stale)
287	305	nfsdstats.fh_stale++;
288	306	return error;