[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 <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/mm/filemap.c b/mm/filemap.c
index 1d33fec..4a2fee2 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1968,6 +1968,7 @@
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 @@
* 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 @@
filemap_set_next_iovec(&cur_iov,
&iov_base, status);
buf = cur_iov->iov_base + iov_base;
+ } else {
+ iov_base += status;
}
}
}