5.10-stable review patch. If anyone has any objections, please let me know.
------------------
From: Chuck Lever chuck.lever@oracle.com
[ Upstream commit 7f87fc2d34d475225e78b7f5c4eabb121f4282b2 ]
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@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 9e8481242dea8..781bb2b115e74 100644 --- a/fs/nfsd/nfs3proc.c +++ b/fs/nfsd/nfs3proc.c @@ -446,18 +446,30 @@ 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; }
/* @@ -476,16 +488,13 @@ 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);
@@ -509,11 +518,9 @@ 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;
@@ -527,7 +534,7 @@ 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 3d076d3c5c7b8..f38d845ac8a0f 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 a4cdd8ccb175a..81dea78b0f17e 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);