Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
fs/nfs/nfs2xdr.c | 173 +++++++++++++++++++++++++++++++++++++++++++++++-------
1 files changed, 152 insertions(+), 21 deletions(-)
diff --git a/fs/nfs/nfs2xdr.c b/fs/nfs/nfs2xdr.c
index 565a5c6..1d65103 100644
--- a/fs/nfs/nfs2xdr.c
+++ b/fs/nfs/nfs2xdr.c
@@ -834,27 +834,6 @@ err_unmap:
goto out;
}
-__be32 *
-nfs_decode_dirent(__be32 *p, struct nfs_entry *entry, int plus)
-{
- if (!*p++) {
- if (!*p)
- return ERR_PTR(-EAGAIN);
- entry->eof = 1;
- return ERR_PTR(-EBADCOOKIE);
- }
-
- entry->ino = ntohl(*p++);
- entry->len = ntohl(*p++);
- entry->name = (const char *) p;
- p += XDR_QUADLEN(entry->len);
- entry->prev_cookie = entry->cookie;
- entry->cookie = ntohl(*p++);
- entry->eof = !p[0] && p[1];
-
- return p;
-}
-
/*
* NFS XDR decode functions
*/
@@ -1110,6 +1089,158 @@ static int nfs2_xdr_dec_writeres(struct rpc_rqst *req, __be32 *p,
}
/*
+ * 2.2.17. entry
+ *
+ * struct entry {
+ * unsigned fileid;
+ * filename name;
+ * nfscookie cookie;
+ * entry *nextentry;
+ * };
+ *
+ * The type (size) of nfscookie isn't defined in RFC 1094.
+ * The "nextentry" field is not used; instead, each entry
+ * is preceded by a boolean "entry follows" field.
+ *
+ * The Linux implementation is limited to receiving not more
+ * than a single page of entries at a time.
+ *
+ * Here, the XDR buffer is checked for correct syntax. The
+ * actual decoding is done by nfs_decode_entry() during
+ * subsequent nfs_readdir() calls.
+ */
+static int decode_readdirok(struct xdr_stream *xdr)
+{
+ struct xdr_buf *rcvbuf = xdr->buf;
+ struct page **page = rcvbuf->pages;
+ __be32 *p, *end, *entry, *kaddr;
+ unsigned int nr, pglen, recvd;
+ size_t hdrlen;
+
+ pglen = rcvbuf->page_len;
+ hdrlen = (u8 *)xdr->p - (u8 *)xdr->iov->iov_base;
+ recvd = rcvbuf->len - hdrlen;
+ if (pglen > recvd)
+ pglen = recvd;
+ xdr_read_pages(xdr, pglen);
+ kaddr = p = kmap_atomic(*page, KM_USER0);
+ end = (__be32 *)((char *)p + pglen);
+ entry = p;
+
+ /* Make sure the packet actually has a value_follows and EOF entry */
+ if ((entry + 1) > end)
+ goto short_pkt;
+
+ nr = 0;
+ for (; *p++; nr++) {
+ u32 len;
+
+ if (p + 2 > end)
+ goto short_pkt;
+ p++; /* fileid */
+ len = be32_to_cpup(p++);
+ if (len > NFS2_MAXNAMLEN) {
+ dprintk("NFS: giant filename in readdir (len 0x%x)!\n",
+ len);
+ goto err_unmap;
+ }
+ p += XDR_QUADLEN(len) + 1; /* name plus cookie */
+ if (p + 2 > end)
+ goto short_pkt;
+ entry = p;
+ }
+
+ /*
+ * Apparently some server sends responses that are a valid size, but
+ * contain no entries, and have value_follows==0 and EOF==0. For
+ * those, just set the EOF marker.
+ */
+ if (!nr && entry[1] == 0) {
+ dprintk("NFS: readdir reply truncated!\n");
+ entry[1] = 1;
+ }
+out:
+ kunmap_atomic(kaddr, KM_USER0);
+ return nr;
+short_pkt:
+ /*
+ * When we get a short packet there are 2 possibilities. We can
+ * return an error, or fix up the response to look like a valid
+ * response and return what we have so far. If there are no
+ * entries and the packet was short, then return -EIO. If there
+ * are valid entries in the response, return them and pretend that
+ * the call was successful, but incomplete. The caller can retry the
+ * readdir starting at the last cookie.
+ */
+ dprintk("%s: short packet at entry %d\n", __func__, nr);
+ entry[0] = entry[1] = 0;
+ if (nr)
+ goto out;
+err_unmap:
+ kunmap_atomic(kaddr, KM_USER0);
+ return -EIO;
+}
+
+/*
+ * 2.2.17. readdirres
+ *
+ * union readdirres switch (stat status) {
+ * case NFS_OK:
+ * struct {
+ * entry *entries;
+ * bool eof;
+ * } readdirok;
+ * default:
+ * void;
+ * };
+ */
+static int nfs2_xdr_dec_readdirres(struct rpc_rqst *req, __be32 *p,
+ void *__unused)
+{
+ struct xdr_stream xdr;
+ enum nfs_stat status;
+
+ xdr_init_decode(&xdr, &req->rq_rcv_buf, p);
+ if (decode_stat(&xdr, &status) != 0)
+ return -EIO;
+ if (status != NFS_OK)
+ return nfs_stat_to_errno(status);
+ return decode_readdirok(&xdr);
+}
+
+/**
+ * nfs_decode_dirent - Decode a single NFSv2 directory entry stored in
+ * the local page cache.
+ * @p: pointer to buffer where entry resides
+ * @entry: entry struct to fill out with data
+ * @plus: boolean indicating whether this should be a readdirplus entry
+ *
+ * Returns the position of the next item in the buffer, or an ERR_PTR.
+ *
+ * This function is not invoked during READDIR reply processing, but
+ * rather whenever an application invokes the getdents(2) system call.
+ */
+__be32 *nfs_decode_dirent(__be32 *p, struct nfs_entry *entry, int plus)
+{
+ if (!*p++) {
+ if (!*p)
+ return ERR_PTR(-EAGAIN);
+ entry->eof = 1;
+ return ERR_PTR(-EBADCOOKIE);
+ }
+
+ entry->ino = be32_to_cpup(p++);
+ entry->len = be32_to_cpup(p++);
+ entry->name = (const char *)p;
+ p += XDR_QUADLEN(entry->len);
+ entry->prev_cookie = entry->cookie;
+ entry->cookie = be32_to_cpup(p++);
+
+ entry->eof = !p[0] && p[1];
+ return p;
+}
+
+/*
* Decode STATFS reply
*/
static int
--
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