[PATCH e2fsprogs 1/5] fsck: consume -l option instead of passing to e2fsck

[Baokun Li <libaokun@linux.alibaba.com>]

The -l (lockdisk) option was introduced by util-linux in commit
dd0bd943f9 ("fsck: add support for whole-disk locking (-l option)",
2010-10-26, first released in v2.19). systemd-fsck passes -l to
/sbin/fsck for parallel fsck support since commit 87c3e6c ("fsck:
pass -l to fsck").

Currently the e2fsprogs fsck wrapper (misc/fsck.c, installed via
make install) does not recognize -l and passes it through to e2fsck.
Since e2fsck's getopt string declares "l:" (requires argument), it
consumes the next argument as the bad_blocks_file parameter. This
triggers a chain of failures:

  systemd-fsck -> fsck -a -T -l -M -C6 /dev/sda
    -> wrapper consumes -a,-T,-M,-C6, adds -C<fd>, passes -l
      -> fsck.ext4 -a -l -C<fd> /dev/sda
        -> e2fsck getopt: -l consumes -C<fd> as bad_blocks_file
          -> journal recovery
          -> orphan cleanup (orphan inodes processed)
          -> fopen("-C<fd>", "r") fails -> E2F_FLAG_ABORT
            -> superblock not flushed (s_last_orphan still non-zero)
              -> kernel: "bad orphan inode" on next mount

This is because the e2fsprogs wrapper lacks a case for -l in its
option parsing, unlike the util-linux wrapper which handles it
correctly (lockdisk = 1).

Fix by adding case 'l': break; to consume the option in the wrapper,
matching util-linux's behavior. Users can still pass -l to e2fsck
via the "--" separator (e.g., "fsck -- -l badblocks_file /dev/sda")
or by invoking e2fsck directly.

Signed-off-by: Baokun Li <libaokun@linux.alibaba.com>
---
 misc/fsck.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/misc/fsck.c b/misc/fsck.c
index 44577590bca5..cb935e1b4b71 100644
--- a/misc/fsck.c
+++ b/misc/fsck.c
@@ -1212,6 +1212,9 @@ static void PRS(int argc, char *argv[])
 			case 'M':
 				ignore_mounted++;
 				break;
+			case 'l':
+				/* lockdisk option from util-linux fsck, consumed by wrapper */
+				break;
 			case 'P':
 				parallel_root++;
 				break;
-- 
2.43.7