f2fs: Fix type of section block count variables

Commit 4aa19f3a341d ("f2fs: get the right gc victim section when section
has several segments") added code to count blocks of each section using
variables with type 'unsigned short', which has 2 bytes size in many
systems. However, the counts can be larger than the 2 bytes range and
type conversion results in wrong values. Especially when the f2fs
sections have blocks as many as USHRT_MAX + 1, the count is handled as 0.
This triggers eternal loop in init_dirty_segmap() at mount system call.
Fix this by changing the type of the variables to block_t.

Fixes: 4aa19f3a341d ("f2fs: get the right gc victim section when section has several segments")
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index a65d357f89a9fad7ec74d7716aea268e702c3f4a..e247a5ef3713fb5a1308792fccaec8373ff058f0 100644 (file)
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -799,7 +799,7 @@ static void __locate_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno,
 
                if (__is_large_section(sbi)) {
                        unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
-                       unsigned short valid_blocks =
+                       block_t valid_blocks =
                                get_valid_blocks(sbi, segno, true);
 
                        f2fs_bug_on(sbi, unlikely(!valid_blocks ||
@@ -815,7 +815,7 @@ static void __remove_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno,
                enum dirty_type dirty_type)
 {
        struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
-       unsigned short valid_blocks;
+       block_t valid_blocks;
 
        if (test_and_clear_bit(segno, dirty_i->dirty_segmap[dirty_type]))
                dirty_i->nr_dirty[dirty_type]--;
@@ -4316,8 +4316,8 @@ static void init_dirty_segmap(struct f2fs_sb_info *sbi)
        struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
        struct free_segmap_info *free_i = FREE_I(sbi);
        unsigned int segno = 0, offset = 0, secno;
-       unsigned short valid_blocks;
-       unsigned short blks_per_sec = BLKS_PER_SEC(sbi);
+       block_t valid_blocks;
+       block_t blks_per_sec = BLKS_PER_SEC(sbi);
 
        while (1) {
                /* find dirty segment based on free segmap */