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, 38 insertions, 0 deletions

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index bfbcff8339c5..049bbeb8ebff 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -186,6 +186,7 @@ bool need_SSR(struct f2fs_sb_info *sbi)
 
 void register_inmem_page(struct inode *inode, struct page *page)
 {
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 	struct f2fs_inode_info *fi = F2FS_I(inode);
 	struct inmem_pages *new;
 
@@ -204,6 +205,10 @@ void register_inmem_page(struct inode *inode, struct page *page)
 	mutex_lock(&fi->inmem_lock);
 	get_page(page);
 	list_add_tail(&new->list, &fi->inmem_pages);
+	spin_lock(&sbi->inode_lock[ATOMIC_FILE]);
+	if (list_empty(&fi->inmem_ilist))
+		list_add_tail(&fi->inmem_ilist, &sbi->inode_list[ATOMIC_FILE]);
+	spin_unlock(&sbi->inode_lock[ATOMIC_FILE]);
 	inc_page_count(F2FS_I_SB(inode), F2FS_INMEM_PAGES);
 	mutex_unlock(&fi->inmem_lock);
 
@@ -262,12 +267,41 @@ next:
 	return err;
 }
 
+void drop_inmem_pages_all(struct f2fs_sb_info *sbi)
+{
+	struct list_head *head = &sbi->inode_list[ATOMIC_FILE];
+	struct inode *inode;
+	struct f2fs_inode_info *fi;
+next:
+	spin_lock(&sbi->inode_lock[ATOMIC_FILE]);
+	if (list_empty(head)) {
+		spin_unlock(&sbi->inode_lock[ATOMIC_FILE]);
+		return;
+	}
+	fi = list_first_entry(head, struct f2fs_inode_info, inmem_ilist);
+	inode = igrab(&fi->vfs_inode);
+	spin_unlock(&sbi->inode_lock[ATOMIC_FILE]);
+
+	if (inode) {
+		drop_inmem_pages(inode);
+		iput(inode);
+	}
+	congestion_wait(BLK_RW_ASYNC, HZ/50);
+	cond_resched();
+	goto next;
+}
+
 void drop_inmem_pages(struct inode *inode)
 {
+	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 	struct f2fs_inode_info *fi = F2FS_I(inode);
 
 	mutex_lock(&fi->inmem_lock);
 	__revoke_inmem_pages(inode, &fi->inmem_pages, true, false);
+	spin_lock(&sbi->inode_lock[ATOMIC_FILE]);
+	if (!list_empty(&fi->inmem_ilist))
+		list_del_init(&fi->inmem_ilist);
+	spin_unlock(&sbi->inode_lock[ATOMIC_FILE]);
 	mutex_unlock(&fi->inmem_lock);
 
 	clear_inode_flag(inode, FI_ATOMIC_FILE);
@@ -399,6 +433,10 @@ int commit_inmem_pages(struct inode *inode)
 		/* drop all uncommitted pages */
 		__revoke_inmem_pages(inode, &fi->inmem_pages, true, false);
 	}
+	spin_lock(&sbi->inode_lock[ATOMIC_FILE]);
+	if (!list_empty(&fi->inmem_ilist))
+		list_del_init(&fi->inmem_ilist);
+	spin_unlock(&sbi->inode_lock[ATOMIC_FILE]);
 	mutex_unlock(&fi->inmem_lock);
 
 	clear_inode_flag(inode, FI_ATOMIC_COMMIT);