NFSD: Return both a hole and a data segment

But only one of each right now. We'll expand on this in the next patch.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 74645c5..2aff507 100644 (file)
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -4603,7 +4603,7 @@ nfsd4_encode_offload_status(struct nfsd4_compoundres *resp, __be32 nfserr,
 static __be32
 nfsd4_encode_read_plus_data(struct nfsd4_compoundres *resp,
                            struct nfsd4_read *read,
-                           unsigned long maxcount,  u32 *eof)
+                           unsigned long *maxcount, u32 *eof)
 {
        struct xdr_stream *xdr = &resp->xdr;
        struct file *file = read->rd_nf->nf_file;
@@ -4614,20 +4614,20 @@ nfsd4_encode_read_plus_data(struct nfsd4_compoundres *resp,
        __be64 tmp64;
 
        if (hole_pos > read->rd_offset)
-               maxcount = min_t(unsigned long, maxcount, hole_pos - read->rd_offset);
-       maxcount = min_t(unsigned long, maxcount, (xdr->buf->buflen - xdr->buf->len));
+               *maxcount = min_t(unsigned long, *maxcount, hole_pos - read->rd_offset);
+       *maxcount = min_t(unsigned long, *maxcount, (xdr->buf->buflen - xdr->buf->len));
 
        /* Content type, offset, byte count */
        p = xdr_reserve_space(xdr, 4 + 8 + 4);
        if (!p)
                return nfserr_resource;
 
-       read->rd_vlen = xdr_reserve_space_vec(xdr, resp->rqstp->rq_vec, maxcount);
+       read->rd_vlen = xdr_reserve_space_vec(xdr, resp->rqstp->rq_vec, *maxcount);
        if (read->rd_vlen < 0)
                return nfserr_resource;
 
        nfserr = nfsd_readv(resp->rqstp, read->rd_fhp, file, read->rd_offset,
-                           resp->rqstp->rq_vec, read->rd_vlen, &maxcount, eof);
+                           resp->rqstp->rq_vec, read->rd_vlen, maxcount, eof);
        if (nfserr)
                return nfserr;
 
@@ -4635,7 +4635,7 @@ nfsd4_encode_read_plus_data(struct nfsd4_compoundres *resp,
        write_bytes_to_xdr_buf(xdr->buf, starting_len,      &tmp,   4);
        tmp64 = cpu_to_be64(read->rd_offset);
        write_bytes_to_xdr_buf(xdr->buf, starting_len + 4,  &tmp64, 8);
-       tmp = htonl(maxcount);
+       tmp = htonl(*maxcount);
        write_bytes_to_xdr_buf(xdr->buf, starting_len + 12, &tmp,   4);
        return nfs_ok;
 }
@@ -4643,11 +4643,19 @@ nfsd4_encode_read_plus_data(struct nfsd4_compoundres *resp,
 static __be32
 nfsd4_encode_read_plus_hole(struct nfsd4_compoundres *resp,
                            struct nfsd4_read *read,
-                           unsigned long maxcount, u32 *eof)
+                           unsigned long *maxcount, u32 *eof)
 {
        struct file *file = read->rd_nf->nf_file;
+       loff_t data_pos = vfs_llseek(file, read->rd_offset, SEEK_DATA);
+       unsigned long count;
        __be32 *p;
 
+       if (data_pos == -ENXIO)
+               data_pos = i_size_read(file_inode(file));
+       else if (data_pos <= read->rd_offset)
+               return nfserr_resource;
+       count = data_pos - read->rd_offset;
+
        /* Content type, offset, byte count */
        p = xdr_reserve_space(&resp->xdr, 4 + 8 + 8);
        if (!p)
@@ -4655,9 +4663,10 @@ nfsd4_encode_read_plus_hole(struct nfsd4_compoundres *resp,
 
        *p++ = htonl(NFS4_CONTENT_HOLE);
         p   = xdr_encode_hyper(p, read->rd_offset);
-        p   = xdr_encode_hyper(p, maxcount);
+        p   = xdr_encode_hyper(p, count);
 
-       *eof = (read->rd_offset + maxcount) >= i_size_read(file_inode(file));
+       *eof = (read->rd_offset + count) >= i_size_read(file_inode(file));
+       *maxcount = min_t(unsigned long, count, *maxcount);
        return nfs_ok;
 }
 
@@ -4665,7 +4674,7 @@ static __be32
 nfsd4_encode_read_plus(struct nfsd4_compoundres *resp, __be32 nfserr,
                       struct nfsd4_read *read)
 {
-       unsigned long maxcount;
+       unsigned long maxcount, count;
        struct xdr_stream *xdr = &resp->xdr;
        struct file *file;
        int starting_len = xdr->buf->len;
@@ -4688,6 +4697,7 @@ nfsd4_encode_read_plus(struct nfsd4_compoundres *resp, __be32 nfserr,
        maxcount = min_t(unsigned long, maxcount,
                         (xdr->buf->buflen - xdr->buf->len));
        maxcount = min_t(unsigned long, maxcount, read->rd_length);
+       count    = maxcount;
 
        eof = read->rd_offset >= i_size_read(file_inode(file));
        if (eof)
@@ -4696,24 +4706,38 @@ nfsd4_encode_read_plus(struct nfsd4_compoundres *resp, __be32 nfserr,
        pos = vfs_llseek(file, read->rd_offset, SEEK_DATA);
        if (pos == -ENXIO)
                pos = i_size_read(file_inode(file));
+       else if (pos < 0)
+               pos = read->rd_offset;
 
-       if (pos > read->rd_offset) {
-               maxcount = pos - read->rd_offset;
-               nfserr = nfsd4_encode_read_plus_hole(resp, read, maxcount, &eof);
+       if (pos == read->rd_offset) {
+               maxcount = count;
+               nfserr = nfsd4_encode_read_plus_data(resp, read, &maxcount, &eof);
+               if (nfserr)
+                       goto out;
+               count -= maxcount;
+               read->rd_offset += maxcount;
                segments++;
-       } else {
-               nfserr = nfsd4_encode_read_plus_data(resp, read, maxcount, &eof);
+       }
+
+       if (count > 0 && !eof) {
+               maxcount = count;
+               nfserr = nfsd4_encode_read_plus_hole(resp, read, &maxcount, &eof);
+               if (nfserr)
+                       goto out;
+               count -= maxcount;
+               read->rd_offset += maxcount;
                segments++;
        }
 
 out:
-       if (nfserr)
+       if (nfserr && segments == 0)
                xdr_truncate_encode(xdr, starting_len);
        else {
                tmp = htonl(eof);
                write_bytes_to_xdr_buf(xdr->buf, starting_len,     &tmp, 4);
                tmp = htonl(segments);
                write_bytes_to_xdr_buf(xdr->buf, starting_len + 4, &tmp, 4);
+               nfserr = nfs_ok;
        }
 
        return nfserr;