NFSD: Add helper to set up the pages where the dirlist is encoded

De-duplicate some code that is used by both READDIR and READDIRPLUS to build the dirlist in the Reply. Because this code is not related to decoding READ arguments, it is moved to a more appropriate spot. Signed-off-by: Chuck Lever <[email protected]>
Stilmant · Jan 25, 2021 · 40116eb · 40116eb
1 parent 0a8f37f
commit 40116eb
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Showing 3 changed files with 19 additions and 31 deletions.
diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c
@@ -435,6 +435,23 @@ nfsd3_proc_link(struct svc_rqst *rqstp)
 	return rpc_success;
 }
 
+static void nfsd3_init_dirlist_pages(struct svc_rqst *rqstp,
+				     struct nfsd3_readdirres *resp,
+				     int count)
+{
+	count = min_t(u32, count, svc_max_payload(rqstp));
+
+	/* Convert byte count to number of words (i.e. >> 2),
+	 * and reserve room for the NULL ptr & eof flag (-2 words) */
+	resp->buflen = (count >> 2) - 2;
+
+	resp->buffer = page_address(*rqstp->rq_next_page);
+	while (count > 0) {
+		rqstp->rq_next_page++;
+		count -= PAGE_SIZE;
+	}
+}
+
 /*
  * Read a portion of a directory.
  */
@@ -452,16 +469,12 @@ nfsd3_proc_readdir(struct svc_rqst *rqstp)
 				SVCFH_fmt(&argp->fh),
 				argp->count, (u32) argp->cookie);
 
-	/* Make sure we've room for the NULL ptr & eof flag, and shrink to
-	 * client read size */
-	count = (argp->count >> 2) - 2;
+	nfsd3_init_dirlist_pages(rqstp, resp, argp->count);
 
 	/* Read directory and encode entries on the fly */
 	fh_copy(&resp->fh, &argp->fh);
 
-	resp->buflen = count;
 	resp->common.err = nfs_ok;
-	resp->buffer = argp->buffer;
 	resp->rqstp = rqstp;
 	offset = argp->cookie;
 
@@ -513,16 +526,12 @@ nfsd3_proc_readdirplus(struct svc_rqst *rqstp)
 				SVCFH_fmt(&argp->fh),
 				argp->count, (u32) argp->cookie);
 
-	/* Convert byte count to number of words (i.e. >> 2),
-	 * and reserve room for the NULL ptr & eof flag (-2 words) */
-	resp->count = (argp->count >> 2) - 2;
+	nfsd3_init_dirlist_pages(rqstp, resp, argp->count);
 
 	/* Read directory and encode entries on the fly */
 	fh_copy(&resp->fh, &argp->fh);
 
 	resp->common.err = nfs_ok;
-	resp->buffer = argp->buffer;
-	resp->buflen = resp->count;
 	resp->rqstp = rqstp;
 	offset = argp->cookie;
 

diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c
@@ -560,8 +560,6 @@ int
 nfs3svc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p)
 {
 	struct nfsd3_readdirargs *args = rqstp->rq_argp;
-	int len;
-	u32 max_blocksize = svc_max_payload(rqstp);
 
 	p = decode_fh(p, &args->fh);
 	if (!p)
@@ -570,14 +568,6 @@ nfs3svc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p)
 	args->verf   = p; p += 2;
 	args->dircount = ~0;
 	args->count  = ntohl(*p++);
-	len = args->count  = min_t(u32, args->count, max_blocksize);
-
-	while (len > 0) {
-		struct page *p = *(rqstp->rq_next_page++);
-		if (!args->buffer)
-			args->buffer = page_address(p);
-		len -= PAGE_SIZE;
-	}
 
 	return xdr_argsize_check(rqstp, p);
 }
@@ -586,8 +576,6 @@ int
 nfs3svc_decode_readdirplusargs(struct svc_rqst *rqstp, __be32 *p)
 {
 	struct nfsd3_readdirargs *args = rqstp->rq_argp;
-	int len;
-	u32 max_blocksize = svc_max_payload(rqstp);
 
 	p = decode_fh(p, &args->fh);
 	if (!p)
@@ -597,14 +585,6 @@ nfs3svc_decode_readdirplusargs(struct svc_rqst *rqstp, __be32 *p)
 	args->dircount = ntohl(*p++);
 	args->count    = ntohl(*p++);
 
-	len = args->count = min(args->count, max_blocksize);
-	while (len > 0) {
-		struct page *p = *(rqstp->rq_next_page++);
-		if (!args->buffer)
-			args->buffer = page_address(p);
-		len -= PAGE_SIZE;
-	}
-
 	return xdr_argsize_check(rqstp, p);
 }
 

diff --git a/fs/nfsd/xdr3.h b/fs/nfsd/xdr3.h
@@ -93,7 +93,6 @@ struct nfsd3_readdirargs {
 	__u32			dircount;
 	__u32			count;
 	__be32 *		verf;
-	__be32 *		buffer;
 };
 
 struct nfsd3_commitargs {