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authorAl Viro <viro@zeniv.linux.org.uk>2016-07-01 06:34:49 +0300
committerAl Viro <viro@zeniv.linux.org.uk>2016-07-01 06:34:49 +0300
commitb223f4e215b32849b841e750e83a915b670070f5 (patch)
tree75340f6305028de331a17255018869822b3886d2 /mm/fadvise.c
parentf4e6d844bdc142322905d137a9e44e07eee43c5c (diff)
parent0cac643c102c0632dc2cc81e2490b0fec1cac0af (diff)
downloadlinux-b223f4e215b32849b841e750e83a915b670070f5.tar.xz
Merge branch 'd_real' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs into work.misc
Diffstat (limited to 'mm/fadvise.c')
-rw-r--r--mm/fadvise.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/mm/fadvise.c b/mm/fadvise.c
index b8024fa7101d..6c707bfe02fd 100644
--- a/mm/fadvise.c
+++ b/mm/fadvise.c
@@ -126,6 +126,17 @@ SYSCALL_DEFINE4(fadvise64_64, int, fd, loff_t, offset, loff_t, len, int, advice)
*/
start_index = (offset+(PAGE_SIZE-1)) >> PAGE_SHIFT;
end_index = (endbyte >> PAGE_SHIFT);
+ if ((endbyte & ~PAGE_MASK) != ~PAGE_MASK) {
+ /* First page is tricky as 0 - 1 = -1, but pgoff_t
+ * is unsigned, so the end_index >= start_index
+ * check below would be true and we'll discard the whole
+ * file cache which is not what was asked.
+ */
+ if (end_index == 0)
+ break;
+
+ end_index--;
+ }
if (end_index >= start_index) {
unsigned long count = invalidate_mapping_pages(mapping,