nfsd4: allow large readdirs
Currently we limit readdir results to a single page. This can result in a performance regression compared to NFSv3 when reading large directories. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This commit is contained in:
J. Bruce Fields
parent
32aaa62ede
commit
561f0ed498
@ -1500,13 +1500,14 @@ static inline u32 nfsd4_read_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
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static inline u32 nfsd4_readdir_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
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{
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u32 maxcount = svc_max_payload(rqstp);
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u32 rlen = op->u.readdir.rd_maxcount;
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if (rlen > PAGE_SIZE)
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rlen = PAGE_SIZE;
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if (rlen > maxcount)
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rlen = maxcount;
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return (op_encode_hdr_size + op_encode_verifier_maxsz)
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* sizeof(__be32) + rlen;
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return (op_encode_hdr_size + op_encode_verifier_maxsz +
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XDR_QUADLEN(rlen)) * sizeof(__be32);
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}
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static inline u32 nfsd4_remove_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
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@ -2575,8 +2575,8 @@ static inline int attributes_need_mount(u32 *bmval)
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}
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static __be32
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nfsd4_encode_dirent_fattr(struct nfsd4_readdir *cd,
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const char *name, int namlen, __be32 **p, int buflen)
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nfsd4_encode_dirent_fattr(struct xdr_stream *xdr, struct nfsd4_readdir *cd,
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const char *name, int namlen)
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{
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struct svc_export *exp = cd->rd_fhp->fh_export;
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struct dentry *dentry;
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@ -2628,8 +2628,7 @@ nfsd4_encode_dirent_fattr(struct nfsd4_readdir *cd,
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}
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out_encode:
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nfserr = nfsd4_encode_fattr_to_buf(p, buflen, NULL, exp, dentry,
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cd->rd_bmval,
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nfserr = nfsd4_encode_fattr(xdr, NULL, exp, dentry, cd->rd_bmval,
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cd->rd_rqstp, ignore_crossmnt);
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out_put:
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dput(dentry);
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@ -2638,9 +2637,12 @@ nfsd4_encode_dirent_fattr(struct nfsd4_readdir *cd,
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}
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static __be32 *
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nfsd4_encode_rdattr_error(__be32 *p, int buflen, __be32 nfserr)
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nfsd4_encode_rdattr_error(struct xdr_stream *xdr, __be32 nfserr)
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{
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if (buflen < 6)
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__be32 *p;
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p = xdr_reserve_space(xdr, 6);
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if (!p)
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return NULL;
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*p++ = htonl(2);
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*p++ = htonl(FATTR4_WORD0_RDATTR_ERROR); /* bmval0 */
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@ -2657,10 +2659,13 @@ nfsd4_encode_dirent(void *ccdv, const char *name, int namlen,
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{
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struct readdir_cd *ccd = ccdv;
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struct nfsd4_readdir *cd = container_of(ccd, struct nfsd4_readdir, common);
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int buflen;
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__be32 *p = cd->buffer;
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__be32 *cookiep;
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struct xdr_stream *xdr = cd->xdr;
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int start_offset = xdr->buf->len;
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int cookie_offset;
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int entry_bytes;
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__be32 nfserr = nfserr_toosmall;
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__be64 wire_offset;
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__be32 *p;
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/* In nfsv4, "." and ".." never make it onto the wire.. */
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if (name && isdotent(name, namlen)) {
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@ -2668,19 +2673,24 @@ nfsd4_encode_dirent(void *ccdv, const char *name, int namlen,
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return 0;
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}
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if (cd->offset)
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xdr_encode_hyper(cd->offset, (u64) offset);
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if (cd->cookie_offset) {
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wire_offset = cpu_to_be64(offset);
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write_bytes_to_xdr_buf(xdr->buf, cd->cookie_offset,
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&wire_offset, 8);
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}
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buflen = cd->buflen - 4 - XDR_QUADLEN(namlen);
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if (buflen < 0)
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p = xdr_reserve_space(xdr, 4);
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if (!p)
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goto fail;
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*p++ = xdr_one; /* mark entry present */
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cookiep = p;
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cookie_offset = xdr->buf->len;
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p = xdr_reserve_space(xdr, 3*4 + namlen);
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if (!p)
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goto fail;
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p = xdr_encode_hyper(p, NFS_OFFSET_MAX); /* offset of next entry */
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p = xdr_encode_array(p, name, namlen); /* name length & name */
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nfserr = nfsd4_encode_dirent_fattr(cd, name, namlen, &p, buflen);
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nfserr = nfsd4_encode_dirent_fattr(xdr, cd, name, namlen);
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switch (nfserr) {
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case nfs_ok:
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break;
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@ -2699,19 +2709,23 @@ nfsd4_encode_dirent(void *ccdv, const char *name, int namlen,
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*/
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if (!(cd->rd_bmval[0] & FATTR4_WORD0_RDATTR_ERROR))
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goto fail;
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p = nfsd4_encode_rdattr_error(p, buflen, nfserr);
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p = nfsd4_encode_rdattr_error(xdr, nfserr);
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if (p == NULL) {
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nfserr = nfserr_toosmall;
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goto fail;
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}
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}
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cd->buflen -= (p - cd->buffer);
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cd->buffer = p;
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cd->offset = cookiep;
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nfserr = nfserr_toosmall;
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entry_bytes = xdr->buf->len - start_offset;
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if (entry_bytes > cd->rd_maxcount)
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goto fail;
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cd->rd_maxcount -= entry_bytes;
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cd->cookie_offset = cookie_offset;
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skip_entry:
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cd->common.err = nfs_ok;
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return 0;
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fail:
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xdr_truncate_encode(xdr, start_offset);
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cd->common.err = nfserr;
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return -EINVAL;
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}
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@ -3206,10 +3220,11 @@ static __be32
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nfsd4_encode_readdir(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_readdir *readdir)
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{
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int maxcount;
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int bytes_left;
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loff_t offset;
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__be64 wire_offset;
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struct xdr_stream *xdr = &resp->xdr;
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int starting_len = xdr->buf->len;
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__be32 *page, *tailbase;
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__be32 *p;
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if (nfserr)
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@ -3219,38 +3234,38 @@ nfsd4_encode_readdir(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4
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if (!p)
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return nfserr_resource;
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if (resp->xdr.buf->page_len)
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return nfserr_resource;
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if (!*resp->rqstp->rq_next_page)
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return nfserr_resource;
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/* XXX: Following NFSv3, we ignore the READDIR verifier for now. */
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WRITE32(0);
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WRITE32(0);
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resp->xdr.buf->head[0].iov_len = ((char *)resp->xdr.p)
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- (char *)resp->xdr.buf->head[0].iov_base;
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tailbase = p;
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maxcount = PAGE_SIZE;
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if (maxcount > readdir->rd_maxcount)
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maxcount = readdir->rd_maxcount;
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/*
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* Convert from bytes to words, account for the two words already
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* written, make sure to leave two words at the end for the next
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* pointer and eof field.
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* Number of bytes left for directory entries allowing for the
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* final 8 bytes of the readdir and a following failed op:
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*/
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maxcount = (maxcount >> 2) - 4;
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if (maxcount < 0) {
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nfserr = nfserr_toosmall;
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bytes_left = xdr->buf->buflen - xdr->buf->len
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- COMPOUND_ERR_SLACK_SPACE - 8;
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if (bytes_left < 0) {
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nfserr = nfserr_resource;
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goto err_no_verf;
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}
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maxcount = min_t(u32, readdir->rd_maxcount, INT_MAX);
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/*
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* Note the rfc defines rd_maxcount as the size of the
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* READDIR4resok structure, which includes the verifier above
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* and the 8 bytes encoded at the end of this function:
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*/
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if (maxcount < 16) {
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nfserr = nfserr_toosmall;
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goto err_no_verf;
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}
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maxcount = min_t(int, maxcount-16, bytes_left);
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page = page_address(*(resp->rqstp->rq_next_page++));
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readdir->xdr = xdr;
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readdir->rd_maxcount = maxcount;
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readdir->common.err = 0;
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readdir->buflen = maxcount;
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readdir->buffer = page;
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readdir->offset = NULL;
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readdir->cookie_offset = 0;
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offset = readdir->rd_cookie;
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nfserr = nfsd_readdir(readdir->rd_rqstp, readdir->rd_fhp,
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@ -3258,33 +3273,31 @@ nfsd4_encode_readdir(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4
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&readdir->common, nfsd4_encode_dirent);
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if (nfserr == nfs_ok &&
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readdir->common.err == nfserr_toosmall &&
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readdir->buffer == page)
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nfserr = nfserr_toosmall;
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xdr->buf->len == starting_len + 8) {
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/* nothing encoded; which limit did we hit?: */
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if (maxcount - 16 < bytes_left)
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/* It was the fault of rd_maxcount: */
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nfserr = nfserr_toosmall;
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else
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/* We ran out of buffer space: */
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nfserr = nfserr_resource;
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}
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if (nfserr)
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goto err_no_verf;
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if (readdir->offset)
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xdr_encode_hyper(readdir->offset, offset);
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if (readdir->cookie_offset) {
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wire_offset = cpu_to_be64(offset);
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write_bytes_to_xdr_buf(xdr->buf, readdir->cookie_offset,
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&wire_offset, 8);
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}
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p = readdir->buffer;
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p = xdr_reserve_space(xdr, 8);
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if (!p) {
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WARN_ON_ONCE(1);
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goto err_no_verf;
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}
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*p++ = 0; /* no more entries */
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*p++ = htonl(readdir->common.err == nfserr_eof);
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resp->xdr.buf->page_len = ((char *)p) -
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(char*)page_address(*(resp->rqstp->rq_next_page-1));
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xdr->buf->len += xdr->buf->page_len;
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xdr->iov = xdr->buf->tail;
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xdr->page_ptr++;
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xdr->buf->buflen -= PAGE_SIZE;
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xdr->iov = xdr->buf->tail;
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/* Use rest of head for padding and remaining ops: */
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resp->xdr.buf->tail[0].iov_base = tailbase;
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resp->xdr.buf->tail[0].iov_len = 0;
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resp->xdr.p = resp->xdr.buf->tail[0].iov_base;
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resp->xdr.end = resp->xdr.p +
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(PAGE_SIZE - resp->xdr.buf->head[0].iov_len)/4;
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return 0;
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err_no_verf:
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@ -287,9 +287,8 @@ struct nfsd4_readdir {
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struct svc_fh * rd_fhp; /* response */
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struct readdir_cd common;
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__be32 * buffer;
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int buflen;
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__be32 * offset;
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struct xdr_stream *xdr;
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int cookie_offset;
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};
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struct nfsd4_release_lockowner {
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