leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

mm: khugepaged: fix radix tree node leak in shmem collapse error path

Browse Source 
The radix tree counts valid entries in each tree node.  Entries stored
in the tree cannot be removed by simpling storing NULL in the slot or
the internal counters will be off and the node never gets freed again.

When collapsing a shmem page fails, restore the holes that were filled
with radix_tree_insert() with a proper radix tree deletion.

Fixes: f3f0e1d215 ("khugepaged: add support of collapse for tmpfs/shmem pages")
Link: http://lkml.kernel.org/r/20161117191138.22769-3-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Jan Kara <jack@suse.cz>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <mawilcox@linuxonhyperv.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Johannes Weiner 2016-12-12 16:43:35 -08:00 committed by Linus Torvalds
parent 91a45f7107
commit 59749e6ce5
1 changed files with 4 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
mm/khugepaged.c
View File

@ -1525,9 +1525,11 @@ tree_unlocked:
if (!page || iter.index < page->index) {
if (!nr_none)
break;
/* Put holes back where they were */
radix_tree_replace_slot(slot, NULL);
nr_none--;
/* Put holes back where they were */
radix_tree_delete(&mapping->page_tree,
iter.index);
slot = radix_tree_iter_next(&iter);
continue;
}