From: Martin Schwidefsky Date: Mon, 6 Jun 2005 20:35:54 +0000 (-0700) Subject: [PATCH] broken fault_in_pages_readable call in generic_file_buffered_write() X-Git-Tag: v2.6.12~106 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a51171816826b074828fa96cb6ef60fc3b13631a;p=linux-2.6 [PATCH] broken fault_in_pages_readable call in generic_file_buffered_write() fault_in_pages_readable() is being passed an incorrect `end' address, which can result in writes accidentally faulting in pages which will not be affected by the write() call. Signed-off-by: Martin Schwidefsky Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/mm/filemap.c b/mm/filemap.c index 1d33fec7ba..4a2fee2cb6 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1968,6 +1968,7 @@ generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov, do { unsigned long index; unsigned long offset; + unsigned long maxlen; size_t copied; offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */ @@ -1982,7 +1983,10 @@ generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov, * same page as we're writing to, without it being marked * up-to-date. */ - fault_in_pages_readable(buf, bytes); + maxlen = cur_iov->iov_len - iov_base; + if (maxlen > bytes) + maxlen = bytes; + fault_in_pages_readable(buf, maxlen); page = __grab_cache_page(mapping,index,&cached_page,&lru_pvec); if (!page) { @@ -2024,6 +2028,8 @@ generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov, filemap_set_next_iovec(&cur_iov, &iov_base, status); buf = cur_iov->iov_base + iov_base; + } else { + iov_base += status; } } }