f2fs: fix null reference error when checking end of zone

[ Upstream commit c82bc1ab2a8a5e73d9728e80c4c2ed87e8921a38 ]

This patch fixes a potentially null pointer being accessed by
is_end_zone_blkaddr() that checks the last block of a zone
when f2fs is mounted as a single device.

Fixes: e067dc3c6b9c ("f2fs: maintain six open zones for zoned devices")
Signed-off-by: Daejun Park <daejun7.park@samsung.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Reviewed-by: Daeho Jeong <daehojeong@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 03bfba48b1cf9d94c9a79e1db9726fd113d13700..467f67cf2b380007f11bff217f91391e6b481135 100644 (file)
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -925,6 +925,7 @@ alloc_new:
 #ifdef CONFIG_BLK_DEV_ZONED
 static bool is_end_zone_blkaddr(struct f2fs_sb_info *sbi, block_t blkaddr)
 {
+       struct block_device *bdev = sbi->sb->s_bdev;
        int devi = 0;
 
        if (f2fs_is_multi_device(sbi)) {
@@ -935,8 +936,9 @@ static bool is_end_zone_blkaddr(struct f2fs_sb_info *sbi, block_t blkaddr)
                        return false;
                }
                blkaddr -= FDEV(devi).start_blk;
+               bdev = FDEV(devi).bdev;
        }
-       return bdev_is_zoned(FDEV(devi).bdev) &&
+       return bdev_is_zoned(bdev) &&
                f2fs_blkz_is_seq(sbi, devi, blkaddr) &&
                (blkaddr % sbi->blocks_per_blkz == sbi->blocks_per_blkz - 1);
 }