Re: [PATCH 0/9] gfs2: Bugs in "Use GL_NOBLOCK flag for non-blocking lookups"

[Andrew Price <anprice@redhat.com>]

On 19/01/2024 21:20, Andreas Gruenbacher wrote:
> Hello,
> 
> Al Viro has reported issues with commit dd00aaeb3432 ("gfs2: Use
> GL_NOBLOCK flag for non-blocking lookups"):
> 
> * First, parent can now be NULL and dereferencing it in
>    gfs2_dir_check(d_inode(parent), &dentry->d_name, ip) isn't going to
>    work;
> 
> * Second, gfs2_dir_check() can still sleep, which breaks LOOKUP_RCU
>    mode.
> 
> These patches should fix both of these problems.  We'll either need
> these fixes added, or commit dd00aaeb3432 reverted for now.

No issues spotted. I like the gfs2_meta_read() improvement. If it helps:

Reviewed-by: Andrew Price <anprice@redhat.com>

Andy

> Thanks,
> Andreas
> 
> Andreas Gruenbacher (9):
>    gfs2: Fix gfs2_drevalidate NULL pointer dereference
>    gfs2: Pass FGP flags to gfs2_getbuf
>    gfs2: Split gfs2_meta_read_async off from gfs2_meta_read
>    gfs2: Add FGP_NOWAIT support to gfs2_meta_read_async
>    gfs2: Pass FGP flags to gfs2_meta_{,inode_}buffer
>    gfs2: Pass FGP flags to gfs2_dirent_search
>    gfs2: Pass FGP flags to gfs2_dir_check
>    gfs2: Minor gfs2_drevalidate cleanup
>    gfs2: Fix LOOKUP_RCU support in gfs2_drevalidate
> 
>   fs/gfs2/aops.c       |   4 +-
>   fs/gfs2/bmap.c       |  21 ++++----
>   fs/gfs2/dentry.c     |  32 ++++++++-----
>   fs/gfs2/dir.c        |  52 +++++++++++---------
>   fs/gfs2/dir.h        |   2 +-
>   fs/gfs2/file.c       |   4 +-
>   fs/gfs2/glops.c      |   2 +-
>   fs/gfs2/incore.h     |   1 -
>   fs/gfs2/inode.c      |  10 ++--
>   fs/gfs2/meta_io.c    | 112 ++++++++++++++++++++++++++++---------------
>   fs/gfs2/meta_io.h    |  15 +++---
>   fs/gfs2/ops_fstype.c |   4 +-
>   fs/gfs2/quota.c      |   2 +-
>   fs/gfs2/recovery.c   |   2 +-
>   fs/gfs2/rgrp.c       |   5 +-
>   fs/gfs2/super.c      |   6 +--
>   fs/gfs2/xattr.c      |  17 ++++---
>   17 files changed, 173 insertions(+), 118 deletions(-)
>