[v4,0/3] CONFIG_DEBUG_VFS at last

Message

Mateusz Guzik Feb. 9, 2025, 6:55 p.m. UTC

This adds a super basic version just to get the mechanism going, along
with sample usage.

The macro set is incomplete (e.g., lack of locking macros) and
dump_inode routine fails to dump any state yet, to be implemented(tm).

I think despite the primitive state this is complete enough to start
sprinkling asserts as necessary.

v4:
- export dump_inode, fixes building ext4 as a module

v3:
- move dump_inode to fs/inode.c
- s/failed/encountered/
- pr_warn instead of pr_crit, matches dump_mapping

v2:
- correct may_open
- fixed up condition reporting:
before:
VFS_WARN_ON_INODE(__builtin_choose_expr((sizeof(int) ==
sizeof(*(8 ? ((void *)((long)(__builtin_strlen(link)) * 0l)) : (int
*)8))), __builtin_strlen(link), __fortify_strlen(link)) != linklen)
failed for inode ff32f7c350c8aec8
after:
VFS_WARN_ON_INODE(strlen(link) != linklen) failed for inode ff2b81ddca13f338

Mateusz Guzik (3):
  vfs: add initial support for CONFIG_DEBUG_VFS
  vfs: catch invalid modes in may_open()
  vfs: use the new debug macros in inode_set_cached_link()

 fs/inode.c               | 15 ++++++++++++++
 fs/namei.c               |  2 ++
 include/linux/fs.h       | 16 +++-----------
 include/linux/vfsdebug.h | 45 ++++++++++++++++++++++++++++++++++++++++
 lib/Kconfig.debug        |  9 ++++++++
 5 files changed, 74 insertions(+), 13 deletions(-)
 create mode 100644 include/linux/vfsdebug.h