[PATCH] f2fs: don't traverse directory blocks after EOF

[Chao Yu]

All directory blocks are within the scope of i_size, so let's limit
the end_block to just check valid dirent blocks.

Meanwhile, it uses dir_blocks() instead of variable for cleanup in
__f2fs_find_entry().

Signed-off-by: Chao Yu <chao@xxxxxxxxxx>
---
 fs/f2fs/dir.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
index 02c9355176d3..d4591c215f07 100644
--- a/fs/f2fs/dir.c
+++ b/fs/f2fs/dir.c
@@ -305,18 +305,21 @@ static struct f2fs_dir_entry *find_in_level(struct inode *dir,
 	int s = GET_DENTRY_SLOTS(fname->disk_name.len);
 	unsigned int nbucket, nblock;
 	unsigned int bidx, end_block;
+	unsigned long last_block;
 	struct page *dentry_page;
 	struct f2fs_dir_entry *de = NULL;
 	pgoff_t next_pgofs;
 	bool room = false;
 	int max_slots;
 
+	last_block = dir_blocks(dir);
 	nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level);
 	nblock = bucket_blocks(level);
 
 	bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level,
 			       le32_to_cpu(fname->hash) % nbucket);
 	end_block = bidx + nblock;
+	end_block = min_t(unsigned int, end_block, last_block);
 
 	while (bidx < end_block) {
 		/* no need to allocate new dentry pages to all the indices */
@@ -361,7 +364,6 @@ struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir,
 					 const struct f2fs_filename *fname,
 					 struct page **res_page)
 {
-	unsigned long npages = dir_blocks(dir);
 	struct f2fs_dir_entry *de = NULL;
 	unsigned int max_depth;
 	unsigned int level;
@@ -373,7 +375,7 @@ struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir,
 		goto out;
 	}
 
-	if (npages == 0)
+	if (dir_blocks(dir) == 0)
 		goto out;
 
 	max_depth = F2FS_I(dir)->i_current_depth;
-- 
2.40.1