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authorLinus Torvalds <torvalds@linux-foundation.org>2018-01-31 18:46:22 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2018-01-31 18:46:22 -0800
commit73da9e1a9f310a449eeb9bf5735a9cd475fef5e2 (patch)
tree82cd78255b0a480340a8427e7ba5586df8280ac4 /mm/fadvise.c
parentb2fe5fa68642860e7de76167c3111623aa0d5de1 (diff)
parent3f56a2f8030071cf86520ef4fc3045ba6856e610 (diff)
Merge branch 'akpm' (patches from Andrew)
Merge updates from Andrew Morton: - misc fixes - ocfs2 updates - most of MM * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (118 commits) mm: remove PG_highmem description tools, vm: new option to specify kpageflags file mm/swap.c: make functions and their kernel-doc agree mm, memory_hotplug: fix memmap initialization mm: correct comments regarding do_fault_around() mm: numa: do not trap faults on shared data section pages. hugetlb, mbind: fall back to default policy if vma is NULL hugetlb, mempolicy: fix the mbind hugetlb migration mm, hugetlb: further simplify hugetlb allocation API mm, hugetlb: get rid of surplus page accounting tricks mm, hugetlb: do not rely on overcommit limit during migration mm, hugetlb: integrate giga hugetlb more naturally to the allocation path mm, hugetlb: unify core page allocation accounting and initialization mm/memcontrol.c: try harder to decrease [memory,memsw].limit_in_bytes mm/memcontrol.c: make local symbol static mm/hmm: fix uninitialized use of 'entry' in hmm_vma_walk_pmd() include/linux/mmzone.h: fix explanation of lower bits in the SPARSEMEM mem_map pointer mm/compaction.c: fix comment for try_to_compact_pages() mm/page_ext.c: make page_ext_init a noop when CONFIG_PAGE_EXTENSION but nothing uses it zsmalloc: use U suffix for negative literals being shifted ...
Diffstat (limited to 'mm/fadvise.c')
-rw-r--r--mm/fadvise.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/mm/fadvise.c b/mm/fadvise.c
index ec70d6e4b86d..767887f5f3bf 100644
--- a/mm/fadvise.c
+++ b/mm/fadvise.c
@@ -127,7 +127,15 @@ 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) {
+ /*
+ * The page at end_index will be inclusively discarded according
+ * by invalidate_mapping_pages(), so subtracting 1 from
+ * end_index means we will skip the last page. But if endbyte
+ * is page aligned or is at the end of file, we should not skip
+ * that page - discarding the last page is safe enough.
+ */
+ if ((endbyte & ~PAGE_MASK) != ~PAGE_MASK &&
+ endbyte != inode->i_size - 1) {
/* 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