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| author | Trond Myklebust <trond.myklebust@hammerspace.com> | 2018-12-02 15:22:48 -0500 |
|---|---|---|
| committer | Trond Myklebust <trond.myklebust@hammerspace.com> | 2018-12-05 07:11:12 -0500 |
| commit | 16e5e90f0e4f9b7b2e4d08558a2f695e2fa1fb0d (patch) | |
| tree | 3ad2f6300ed7f53e640d8f8c1211397d4fa868cc /net/sunrpc | |
| parent | c443305529d1d3d3bee0d68fdd14ae89835e091f (diff) | |
| download | lwn-16e5e90f0e4f9b7b2e4d08558a2f695e2fa1fb0d.tar.gz lwn-16e5e90f0e4f9b7b2e4d08558a2f695e2fa1fb0d.zip | |
SUNRPC: Fix up handling of the XDRBUF_SPARSE_PAGES flag
If the allocator fails before it has reached the target number of pages,
then we need to recheck that we're not seeking past the page buffer.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Diffstat (limited to 'net/sunrpc')
| -rw-r--r-- | net/sunrpc/xprtsock.c | 22 |
1 files changed, 11 insertions, 11 deletions
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index 0898752cecfe..cd85c492c267 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -330,18 +330,16 @@ xs_alloc_sparse_pages(struct xdr_buf *buf, size_t want, gfp_t gfp) { size_t i,n; - if (!(buf->flags & XDRBUF_SPARSE_PAGES)) + if (!want || !(buf->flags & XDRBUF_SPARSE_PAGES)) return want; - if (want > buf->page_len) - want = buf->page_len; n = (buf->page_base + want + PAGE_SIZE - 1) >> PAGE_SHIFT; for (i = 0; i < n; i++) { if (buf->pages[i]) continue; buf->bvec[i].bv_page = buf->pages[i] = alloc_page(gfp); if (!buf->pages[i]) { - buf->page_len = (i * PAGE_SIZE) - buf->page_base; - return buf->page_len; + i *= PAGE_SIZE; + return i > buf->page_base ? i - buf->page_base : 0; } } return want; @@ -404,10 +402,11 @@ xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags, seek -= buf->head[0].iov_len; offset += buf->head[0].iov_len; } - if (seek < buf->page_len) { - want = xs_alloc_sparse_pages(buf, - min_t(size_t, count - offset, buf->page_len), - GFP_NOWAIT); + + want = xs_alloc_sparse_pages(buf, + min_t(size_t, count - offset, buf->page_len), + GFP_NOWAIT); + if (seek < want) { ret = xs_read_bvec(sock, msg, flags, buf->bvec, xdr_buf_pagecount(buf), want + buf->page_base, @@ -421,9 +420,10 @@ xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags, goto out; seek = 0; } else { - seek -= buf->page_len; - offset += buf->page_len; + seek -= want; + offset += want; } + if (seek < buf->tail[0].iov_len) { want = min_t(size_t, count - offset, buf->tail[0].iov_len); ret = xs_read_kvec(sock, msg, flags, &buf->tail[0], want, seek); |