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authorMartin Schwidefsky <schwidefsky@de.ibm.com>2005-06-06 13:35:54 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-06-06 14:42:23 -0700
commita51171816826b074828fa96cb6ef60fc3b13631a (patch)
treee3c6f7a9852d45e9fdec75d7c71548ba404625e7
parent7cef5677ef3a8084f2588ce0a129dc95d65161f6 (diff)
downloadlinux-a51171816826b074828fa96cb6ef60fc3b13631a.tar.gz
[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>
-rw-r--r--mm/filemap.c8
1 files changed, 7 insertions, 1 deletions
diff --git a/mm/filemap.c b/mm/filemap.c
index 1d33fec7bac6..4a2fee2cb62b 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;
 				}
 			}
 		}