9p: skip over-long directory entry names for legacy 9p2000 too

The legacy 9p2000 and 9p2000.u readdir path, v9fs_dir_readdir(), parses
each entry with p9stat_read() and, unlike the 9p2000.L path, never had
a 256-byte name limit: a name of any length up to the wire maximum was
handed to dir_emit(). getdents64() therefore returned names longer than
NAME_MAX that no later syscall can use, and failed with -EIO for names
of PATH_MAX bytes or more.

Apply the same NAME_MAX check as the previous patch does for
v9fs_dir_readdir_dotl(), so both protocol variants behave the same.

Note that this is a behaviour change for 9p2000 and 9p2000.u,
Name length 256..4095:
  - before: listed, but unusable (ENAMETOOLONG)
  - now: entry skipped, fetch continues
Name length >=4096:
  - before: aborts the entire fetch (similar to 9p2000.L side)
  - now: entry skipped, fetch continues

Suggested-by: Christian Schoenebeck <linux_oss@crudebyte.com>
Link: https://lore.kernel.org/all/3910569.MHq7AAxBmi@weasel/
Signed-off-by: Haobin Wu <853555@gmail.com>
Message-ID: <20260918024851.51229-4-853555@gmail.com>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>

0 files changed, 0 insertions, 0 deletions