From 278765ea0752e67922c0f2aaf1138f6ba227688d Mon Sep 17 00:00:00 2001 From: Anna Schumaker Date: Mon, 28 Sep 2020 13:09:00 -0400 Subject: [PATCH] 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 Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4xdr.c | 56 +++++++++++++++++++++++++++++++++-------------- 1 file changed, 40 insertions(+), 16 deletions(-) diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index 74645c5c44bd..2aff50745d6d 100644 --- 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;