[GIT PULL] afs: Miscellaneous fixes

[David Howells <dhowells@redhat.com>]

Hi Linus,

Here are a set of miscellaneous small fixes to the afs filesystem
including:

 (1) Fix the afs_server_list struct to be cleaned up with RCU.

 (2) Fix afs to translate a no-data result from a DNS lookup into ENOENT,
     not EDESTADDRREQ for consistency with OpenAFS.

 (3) Fix afs to translate a negative DNS lookup result into ENOENT rather
     than EDESTADDRREQ.

 (4) Fix file locking on R/O volumes to operate in local mode as the server
     doesn't handle exclusive locks on such files.

 (5) Set SB_RDONLY on superblocks for RO and Backup volumes so that the VFS
     can see that they're read only.

Btw, I did want to ask about (5): Does a superblock being marked SB_RDONLY
imply immutability to the application?  A 'read only' AFS volume is a snapshot
of a writable volume and can be updated.  It's only read-only in the sense you
can't perform normal filesystem modification ops on it.

Link: https://lore.kernel.org/r/20231116155312.156593-1-dhowells@redhat.com/ # v1
Reviewed-by: Jeffrey Altman <jaltman@auristor.com>

Thanks,
David

---
The following changes since commit 76df934c6d5f5c93ba7a0112b1818620ddc10b19:

  MAINTAINERS: Add netdev subsystem profile link (2023-11-17 03:44:21 +0000)

are available in the Git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git tags/afs-fixes-20231124

for you to fetch changes up to 68516f60c1d8b0a71e516d630f66b99cb50e0150:

  afs: Mark a superblock for an R/O or Backup volume as SB_RDONLY (2023-11-24 14:52:24 +0000)

----------------------------------------------------------------
AFS Fixes

----------------------------------------------------------------
David Howells (5):
      afs: Fix afs_server_list to be cleaned up with RCU
      afs: Make error on cell lookup failure consistent with OpenAFS
      afs: Return ENOENT if no cell DNS record can be found
      afs: Fix file locking on R/O volumes to operate in local mode
      afs: Mark a superblock for an R/O or Backup volume as SB_RDONLY

 fs/afs/dynroot.c     |  4 ++--
 fs/afs/internal.h    |  1 +
 fs/afs/server_list.c |  2 +-
 fs/afs/super.c       |  4 ++++
 fs/afs/vl_rotate.c   | 10 ++++++++++
 5 files changed, 18 insertions(+), 3 deletions(-)