f2fs: check truncation of mapping after lock_page

We call lock_page when we need to update a page after readpage.
Between grab and lock page, the page can be truncated by other thread.
So, we should check the page after lock_page whether it was truncated or not.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

1 files changed, 16 insertions, 4 deletions

diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index aede91071f71..6ff017245522 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -674,6 +674,7 @@ fail:
 int truncate_inode_blocks(struct inode *inode, pgoff_t from)
 {
         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
+        struct address_space *node_mapping = sbi->node_inode->i_mapping;
         int err = 0, cont = 1;
         int level, offset[4], noffset[4];
         unsigned int nofs = 0;
@@ -684,7 +685,7 @@ int truncate_inode_blocks(struct inode *inode, pgoff_t from)
         trace_f2fs_truncate_inode_blocks_enter(inode, from);
 
         level = get_node_path(from, offset, noffset);
-
+restart:
         page = get_node_page(sbi, inode->i_ino);
         if (IS_ERR(page)) {
                 trace_f2fs_truncate_inode_blocks_exit(inode, PTR_ERR(page));
@@ -748,6 +749,10 @@ skip_partial:
                 if (offset[1] == 0 &&
                                 rn->i.i_nid[offset[0] - NODE_DIR1_BLOCK]) {
                         lock_page(page);
+                        if (page->mapping != node_mapping) {
+                                f2fs_put_page(page, 1);
+                                goto restart;
+                        }
                         wait_on_page_writeback(page);
                         rn->i.i_nid[offset[0] - NODE_DIR1_BLOCK] = 0;
                         set_page_dirty(page);
@@ -916,7 +921,7 @@ struct page *get_node_page(struct f2fs_sb_info *sbi, pgoff_t nid)
         struct address_space *mapping = sbi->node_inode->i_mapping;
         struct page *page;
         int err;
-
+repeat:
         page = grab_cache_page(mapping, nid);
         if (!page)
                 return ERR_PTR(-ENOMEM);
@@ -932,6 +937,10 @@ struct page *get_node_page(struct f2fs_sb_info *sbi, pgoff_t nid)
                 f2fs_put_page(page, 1);
                 return ERR_PTR(-EIO);
         }
+        if (page->mapping != mapping) {
+                f2fs_put_page(page, 1);
+                goto repeat;
+        }
 got_it:
         BUG_ON(nid != nid_of_node(page));
         mark_page_accessed(page);
@@ -955,7 +964,7 @@ struct page *get_node_page_ra(struct page *parent, int start)
         nid = get_nid(parent, start, false);
         if (!nid)
                 return ERR_PTR(-ENOENT);
-
+repeat:
         page = grab_cache_page(mapping, nid);
         if (!page)
                 return ERR_PTR(-ENOMEM);
@@ -981,7 +990,10 @@ struct page *get_node_page_ra(struct page *parent, int start)
         blk_finish_plug(&plug);
 
         lock_page(page);
-
+        if (page->mapping != mapping) {
+                f2fs_put_page(page, 1);
+                goto repeat;
+        }
 page_hit:
         if (!PageUptodate(page)) {
                 f2fs_put_page(page, 1);