f2fs: limit # of inmemory pages

If some abnormal users try lots of atomic write operations, f2fs is able to
produce pinned pages in the main memory which affects system performance.
This patch limits that as 20% over total memory size, and if f2fs reaches
to the limit, it will drop all the inmemory pages.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/fs/f2fs/node.h b/fs/f2fs/node.h
index e91b08b4a51a..0ee3e5ff49a3 100644
--- a/fs/f2fs/node.h
+++ b/fs/f2fs/node.h
@@ -140,6 +140,7 @@ enum mem_type {
 	DIRTY_DENTS,	/* indicates dirty dentry pages */
 	INO_ENTRIES,	/* indicates inode entries */
 	EXTENT_CACHE,	/* indicates extent cache */
+	INMEM_PAGES,	/* indicates inmemory pages */
 	BASE_CHECK,	/* check kernel status */
 };