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f2fs: use PGP_LOCK to check its truncation

PATCH New Jaegeuk Kim 1 participant 2 messages Mar 30, 2016

Subsystems (2)
VFS F2FS file system
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Jaegeuk Kim

author maintainer
#0 lore raw

PATCH 1/2 f2fs: use PGP_LOCK to check its truncation

Previously, after trylock_page is succeeded, it doesn't check its mapping. In order to fix that, we can just give PGP_LOCK to pagecache_get_page.

Signed-off-by Jaegeuk Kim <[email protected]>
---
 fs/f2fs/node.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)
fs/f2fs/node.c +1 -4
index 118321b..2f2810e 100644
@@ -1202,13 +1202,10 @@ static void flush_inline_data(struct f2fs_sb_info *sbi, nid_t ino)
 	if (!inode)
 		return;
 
-	page = pagecache_get_page(inode->i_mapping, 0, FGP_NOWAIT, 0);
+	page = pagecache_get_page(inode->i_mapping, 0, FGP_LOCK|FGP_NOWAIT, 0);
 	if (!page)
 		goto iput_out;
 
-	if (!trylock_page(page))
-		goto release_out;
-
 	if (!PageUptodate(page))
 		goto page_out;
Signature · 1 line
2.6.3
author maintainer
#1 lore raw

PATCH 2/2 f2fs: add BUG_ON to avoid unnecessary flow

This patch adds BUG_ON instead of retrying loop.
In the case of node pages, we already got this inode page, but unlocked it. By the fact that we don't truncate any node pages in operations, the page's mapping should be unchangeable.

Signed-off-by Jaegeuk Kim <[email protected]>
---
 fs/f2fs/node.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)
fs/f2fs/node.c +2 -5
index 2f2810e..fac22fe 100644
@@ -832,7 +832,7 @@ int truncate_inode_blocks(struct inode *inode, pgoff_t from)
 	trace_f2fs_truncate_inode_blocks_enter(inode, from);
 
 	level = get_node_path(inode, 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));

@@ -896,10 +896,7 @@ skip_partial:
 		if (offset[1] == 0 &&
 				ri->i_nid[offset[0] - NODE_DIR1_BLOCK]) {
 			lock_page(page);
-			if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
-				f2fs_put_page(page, 1);
-				goto restart;
-			}
+			BUG_ON(page->mapping != NODE_MAPPING(sbi));
 			f2fs_wait_on_page_writeback(page, NODE, true);
 			ri->i_nid[offset[0] - NODE_DIR1_BLOCK] = 0;
 			set_page_dirty(page);
Signature · 1 line
2.6.3