The benefit of the xdr_stream helpers is that they transparently
handle encoding an XDR data item that crosses page boundaries.
Most of the open-coded logic to do that here can be eliminated.
A sub-buffer and sub-stream are set up as a sink buffer for the
directory entry encoder. As an entry is encoded, it is added to
the end of the content in this buffer/stream. The total length of
the directory list is tracked in the buffer's @len field.
When it comes time to encode the Reply, the sub-buffer is merged
into rq_res's page array at the correct place using
xdr_write_pages().
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
fs/nfsd/nfs3proc.c | 35 +++++++----
fs/nfsd/nfs3xdr.c | 166 ++++++++++++++++++++++++++++++++++++++++++++++++----
fs/nfsd/xdr3.h | 14 +++-
3 files changed, 185 insertions(+), 30 deletions(-)
diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c
index f1096aa0f47c..bc64e95a168d 100644
--- a/fs/nfsd/nfs3proc.c
+++ b/fs/nfsd/nfs3proc.c
@@ -441,18 +441,30 @@ static void nfsd3_init_dirlist_pages(struct svc_rqst *rqstp,
struct nfsd3_readdirres *resp,
int count)
{
+ struct xdr_buf *buf = &resp->dirlist;
+ struct xdr_stream *xdr = &resp->xdr;
+
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;
+ memset(buf, 0, sizeof(*buf));
- resp->pages = rqstp->rq_next_page;
- resp->buffer = page_address(*resp->pages);
+ /* Reserve room for the NULL ptr & eof flag (-2 words) */
+ buf->buflen = count - XDR_UNIT * 2;
+ buf->pages = rqstp->rq_next_page;
while (count > 0) {
rqstp->rq_next_page++;
count -= PAGE_SIZE;
}
+
+ /* This is xdr_init_encode(), but it assumes that
+ * the head kvec has already been consumed. */
+ xdr_set_scratch_buffer(xdr, NULL, 0);
+ xdr->buf = buf;
+ xdr->page_ptr = buf->pages;
+ xdr->iov = NULL;
+ xdr->p = page_address(*buf->pages);
+ xdr->end = xdr->p + (PAGE_SIZE >> 2);
+ xdr->rqst = NULL;
}
/*
@@ -471,16 +483,13 @@ nfsd3_proc_readdir(struct svc_rqst *rqstp)
nfsd3_init_dirlist_pages(rqstp, resp, argp->count);
- /* Read directory and encode entries on the fly */
fh_copy(&resp->fh, &argp->fh);
-
- resp->count = 0;
resp->common.err = nfs_ok;
+ resp->cookie_offset = 0;
resp->rqstp = rqstp;
offset = argp->cookie;
-
resp->status = nfsd_readdir(rqstp, &resp->fh, &offset,
- &resp->common, nfs3svc_encode_entry);
+ &resp->common, nfs3svc_encode_entry3);
memcpy(resp->verf, argp->verf, 8);
nfs3svc_encode_cookie3(resp, offset);
@@ -504,11 +513,9 @@ nfsd3_proc_readdirplus(struct svc_rqst *rqstp)
nfsd3_init_dirlist_pages(rqstp, resp, argp->count);
- /* Read directory and encode entries on the fly */
fh_copy(&resp->fh, &argp->fh);
-
- resp->count = 0;
resp->common.err = nfs_ok;
+ resp->cookie_offset = 0;
resp->rqstp = rqstp;
offset = argp->cookie;
@@ -522,7 +529,7 @@ nfsd3_proc_readdirplus(struct svc_rqst *rqstp)
}
resp->status = nfsd_readdir(rqstp, &resp->fh, &offset,
- &resp->common, nfs3svc_encode_entry_plus);
+ &resp->common, nfs3svc_encode_entryplus3);
memcpy(resp->verf, argp->verf, 8);
nfs3svc_encode_cookie3(resp, offset);
diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c
index f8362b5ea98f..9c799fec5044 100644
--- a/fs/nfsd/nfs3xdr.c
+++ b/fs/nfsd/nfs3xdr.c
@@ -1139,6 +1139,7 @@ nfs3svc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p)
{
struct xdr_stream *xdr = &rqstp->rq_res_stream;
struct nfsd3_readdirres *resp = rqstp->rq_resp;
+ struct xdr_buf *dirlist = &resp->dirlist;
if (!svcxdr_encode_nfsstat3(xdr, resp->status))
return 0;
@@ -1148,7 +1149,7 @@ nfs3svc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p)
return 0;
if (!svcxdr_encode_cookieverf3(xdr, resp->verf))
return 0;
- xdr_write_pages(xdr, resp->pages, 0, resp->count << 2);
+ xdr_write_pages(xdr, dirlist->pages, 0, dirlist->len);
/* no more entries */
if (xdr_stream_encode_item_absent(xdr) < 0)
return 0;
@@ -1240,21 +1241,18 @@ static __be32 *encode_entryplus_baggage(struct nfsd3_readdirres *cd, __be32 *p,
* @resp: readdir result context
* @offset: offset cookie to encode
*
+ * The buffer space for the offset cookie has already been reserved
+ * by svcxdr_encode_entry3_common().
*/
void nfs3svc_encode_cookie3(struct nfsd3_readdirres *resp, u64 offset)
{
- if (!resp->offset)
- return;
+ __be64 cookie = cpu_to_be64(offset);
- if (resp->offset1) {
- /* we ended up with offset on a page boundary */
- *resp->offset = cpu_to_be32(offset >> 32);
- *resp->offset1 = cpu_to_be32(offset & 0xffffffff);
- resp->offset1 = NULL;
- } else {
- xdr_encode_hyper(resp->offset, offset);
- }
- resp->offset = NULL;
+ if (!resp->cookie_offset)
+ return;
+ write_bytes_to_xdr_buf(&resp->dirlist, resp->cookie_offset, &cookie,
+ sizeof(cookie));
+ resp->cookie_offset = 0;
}
/*
@@ -1403,6 +1401,150 @@ nfs3svc_encode_entry_plus(void *cd, const char *name,
return encode_entry(cd, name, namlen, offset, ino, d_type, 1);
}
+static bool
+svcxdr_encode_entry3_common(struct nfsd3_readdirres *resp, const char *name,
+ int namlen, loff_t offset, u64 ino)
+{
+ struct xdr_buf *dirlist = &resp->dirlist;
+ struct xdr_stream *xdr = &resp->xdr;
+
+ if (xdr_stream_encode_item_present(xdr) < 0)
+ return false;
+ /* fileid */
+ if (xdr_stream_encode_u64(xdr, ino) < 0)
+ return false;
+ /* name */
+ if (xdr_stream_encode_opaque(xdr, name, min(namlen, NFS3_MAXNAMLEN)) < 0)
+ return false;
+ /* cookie */
+ resp->cookie_offset = dirlist->len;
+ if (xdr_stream_encode_u64(xdr, NFS_OFFSET_MAX) < 0)
+ return false;
+
+ return true;
+}
+
+/**
+ * nfs3svc_encode_entry3 - encode one NFSv3 READDIR entry
+ * @data: directory context
+ * @name: name of the object to be encoded
+ * @namlen: length of that name, in bytes
+ * @offset: the offset of the previous entry
+ * @ino: the fileid of this entry
+ * @d_type: unused
+ *
+ * Return values:
+ * %0: Entry was successfully encoded.
+ * %-EINVAL: An encoding problem occured, secondary status code in resp->common.err
+ *
+ * On exit, the following fields are updated:
+ * - resp->xdr
+ * - resp->common.err
+ * - resp->cookie_offset
+ */
+int nfs3svc_encode_entry3(void *data, const char *name, int namlen,
+ loff_t offset, u64 ino, unsigned int d_type)
+{
+ struct readdir_cd *ccd = data;
+ struct nfsd3_readdirres *resp = container_of(ccd,
+ struct nfsd3_readdirres,
+ common);
+ unsigned int starting_length = resp->dirlist.len;
+
+ /* The offset cookie for the previous entry */
+ nfs3svc_encode_cookie3(resp, offset);
+
+ if (!svcxdr_encode_entry3_common(resp, name, namlen, offset, ino))
+ goto out_toosmall;
+
+ xdr_commit_encode(&resp->xdr);
+ resp->common.err = nfs_ok;
+ return 0;
+
+out_toosmall:
+ resp->cookie_offset = 0;
+ resp->common.err = nfserr_toosmall;
+ resp->dirlist.len = starting_length;
+ return -EINVAL;
+}
+
+static bool
+svcxdr_encode_entry3_plus(struct nfsd3_readdirres *resp, const char *name,
+ int namlen, u64 ino)
+{
+ struct xdr_stream *xdr = &resp->xdr;
+ struct svc_fh *fhp = &resp->scratch;
+ bool result;
+
+ result = false;
+ fh_init(fhp, NFS3_FHSIZE);
+ if (compose_entry_fh(resp, fhp, name, namlen, ino) != nfs_ok)
+ goto out_noattrs;
+
+ if (!svcxdr_encode_post_op_attr(resp->rqstp, xdr, fhp))
+ goto out;
+ if (!svcxdr_encode_post_op_fh3(xdr, fhp))
+ goto out;
+ result = true;
+
+out:
+ fh_put(fhp);
+ return result;
+
+out_noattrs:
+ if (xdr_stream_encode_item_absent(xdr) < 0)
+ return false;
+ if (xdr_stream_encode_item_absent(xdr) < 0)
+ return false;
+ return true;
+}
+
+/**
+ * nfs3svc_encode_entryplus3 - encode one NFSv3 READDIRPLUS entry
+ * @data: directory context
+ * @name: name of the object to be encoded
+ * @namlen: length of that name, in bytes
+ * @offset: the offset of the previous entry
+ * @ino: the fileid of this entry
+ * @d_type: unused
+ *
+ * Return values:
+ * %0: Entry was successfully encoded.
+ * %-EINVAL: An encoding problem occured, secondary status code in resp->common.err
+ *
+ * On exit, the following fields are updated:
+ * - resp->xdr
+ * - resp->common.err
+ * - resp->cookie_offset
+ */
+int nfs3svc_encode_entryplus3(void *data, const char *name, int namlen,
+ loff_t offset, u64 ino, unsigned int d_type)
+{
+ struct readdir_cd *ccd = data;
+ struct nfsd3_readdirres *resp = container_of(ccd,
+ struct nfsd3_readdirres,
+ common);
+ unsigned int starting_length = resp->dirlist.len;
+
+ /* The offset cookie for the previous entry */
+ nfs3svc_encode_cookie3(resp, offset);
+
+ if (!svcxdr_encode_entry3_common(resp, name, namlen, offset, ino))
+ goto out_toosmall;
+ if (!svcxdr_encode_entry3_plus(resp, name, namlen, ino))
+ goto out_toosmall;
+
+ xdr_commit_encode(&resp->xdr);
+ resp->common.err = nfs_ok;
+ return 0;
+
+out_toosmall:
+ resp->cookie_offset = 0;
+ resp->common.err = nfserr_toosmall;
+ resp->dirlist.len = starting_length;
+ return -EINVAL;
+}
+
static bool
svcxdr_encode_fsstat3resok(struct xdr_stream *xdr,
const struct nfsd3_fsstatres *resp)
diff --git a/fs/nfsd/xdr3.h b/fs/nfsd/xdr3.h
index a4cdd8ccb175..81dea78b0f17 100644
--- a/fs/nfsd/xdr3.h
+++ b/fs/nfsd/xdr3.h
@@ -169,20 +169,22 @@ struct nfsd3_linkres {
};
struct nfsd3_readdirres {
+ /* Components of the reply */
__be32 status;
struct svc_fh fh;
- /* Just to save kmalloc on every readdirplus entry (svc_fh is a
- * little large for the stack): */
- struct svc_fh scratch;
int count;
__be32 verf[2];
- struct page **pages;
+ /* Used to encode the reply's entry list */
+ struct xdr_stream xdr;
+ struct xdr_buf dirlist;
+ struct svc_fh scratch;
struct readdir_cd common;
__be32 * buffer;
int buflen;
__be32 * offset;
__be32 * offset1;
+ unsigned int cookie_offset;
struct svc_rqst * rqstp;
};
@@ -309,6 +311,10 @@ int nfs3svc_encode_entry(void *, const char *name,
int nfs3svc_encode_entry_plus(void *, const char *name,
int namlen, loff_t offset, u64 ino,
unsigned int);
+int nfs3svc_encode_entry3(void *data, const char *name, int namlen,
+ loff_t offset, u64 ino, unsigned int d_type);
+int nfs3svc_encode_entryplus3(void *data, const char *name, int namlen,
+ loff_t offset, u64 ino, unsigned int d_type);
/* Helper functions for NFSv3 ACL code */
__be32 *nfs3svc_encode_post_op_attr(struct svc_rqst *rqstp, __be32 *p,
struct svc_fh *fhp);
