f2fs: fix to check readonly condition correctly

[ Upstream commit d78dfefcde9d311284434560d69c0478c55a657e ]

With below case, it can mount multi-device image w/ rw option, however
one of secondary device is set as ro, later update will cause panic, so
let's introduce f2fs_dev_is_readonly(), and check multi-devices rw status
in f2fs_remount() w/ it in order to avoid such inconsistent mount status.

mkfs.f2fs -c /dev/zram1 /dev/zram0 -f
blockdev --setro /dev/zram1
mount -t f2fs dev/zram0 /mnt/f2fs
mount: /mnt/f2fs: WARNING: source write-protected, mounted read-only.
mount -t f2fs -o remount,rw mnt/f2fs
dd if=/dev/zero  of=/mnt/f2fs/file bs=1M count=8192

kernel BUG at fs/f2fs/inline.c:258!
RIP: 0010:f2fs_write_inline_data+0x23e/0x2d0 [f2fs]
Call Trace:
  f2fs_write_single_data_page+0x26b/0x9f0 [f2fs]
  f2fs_write_cache_pages+0x389/0xa60 [f2fs]
  __f2fs_write_data_pages+0x26b/0x2d0 [f2fs]
  f2fs_write_data_pages+0x2e/0x40 [f2fs]
  do_writepages+0xd3/0x1b0
  __writeback_single_inode+0x5b/0x420
  writeback_sb_inodes+0x236/0x5a0
  __writeback_inodes_wb+0x56/0xf0
  wb_writeback+0x2a3/0x490
  wb_do_writeback+0x2b2/0x330
  wb_workfn+0x6a/0x260
  process_one_work+0x270/0x5e0
  worker_thread+0x52/0x3e0
  kthread+0xf4/0x120
  ret_from_fork+0x29/0x50

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index a0a232551da97484c6326235100174468dac9887..8d7dc76e6f935a3fac82be34fe9bc0a981ec2929 100644 (file)
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -4435,6 +4435,11 @@ static inline bool f2fs_hw_is_readonly(struct f2fs_sb_info *sbi)
        return false;
 }
 
+static inline bool f2fs_dev_is_readonly(struct f2fs_sb_info *sbi)
+{
+       return f2fs_sb_has_readonly(sbi) || f2fs_hw_is_readonly(sbi);
+}
+
 static inline bool f2fs_lfs_mode(struct f2fs_sb_info *sbi)
 {
        return F2FS_OPTION(sbi).fs_mode == FS_MODE_LFS;

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index c46533d65372c5a33dce1a76d2b03f13099fdb1d..b6dad389fa1445f2bfc5940ef32dbd8069e45bf2 100644 (file)
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -2258,7 +2258,7 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
        if (f2fs_readonly(sb) && (*flags & SB_RDONLY))
                goto skip;
 
-       if (f2fs_sb_has_readonly(sbi) && !(*flags & SB_RDONLY)) {
+       if (f2fs_dev_is_readonly(sbi) && !(*flags & SB_RDONLY)) {
                err = -EROFS;
                goto restore_opts;
        }