[PATCH v4 00/11] cifs: Miscellaneous prep patches for rewrite of I/O layer

David Howells
2025-11-24T12:43:05Z

Hi Steve,

Could you take these patches extracted from my I/O layer rewrite for the
upcoming merge window. The performance change should be neutral, but it
cleans up the code a bit.

(1) Use netfs_alloc/free_folioq_buffer() rather than cifs doing its own
version.

(2) Do some minor cleanups so that patch 2 can be generated wholly by a
script.

(3) Organise the declarations in the cifs client header files, naming the
arguments the same as for the implementations, inserting divider
comments, ordering them the same as they're found in the files and
dividing them better between general, smb1 and smb2/3 categories.

The organisation is entirely scripted with the script in the second
patch's commit message. The first patch does a bit of preparation to
make sure that the second patch's output will build.

By filling in the argument names, this stops checkpatch moaning about
unnamed arguments from search-and-replace changes in later patches.
(Note that it doesn't fix func pointer declarations).

smbdirect is left untouched as requested by Stefan Metzmacher.

(4) Rename struct mid_q_entry to smb_message. In my rewrite, smb_message
will get allocated in the marshalling functions in smb2pdu.c and
cifssmb.c rather than in transport.c and used to hand parameters down
- and so I think it could be better named for that.

(5) Remove the RFC1002 header from the smb_hdr struct so that it's
consistent with SMB2/3. This allows I/O routines to be simplified and
shared.

(6) Make SMB1's SendReceive() wrap cifs_send_recv() and thus share code
with SMB2/3.

(7) Clean up a bunch of extra kvec[] that were required for RFC1002
headers from SMB1's header struct.

(8) Replace SendReceiveBlockingLock() with SendReceive() plus flags.

(9) Remove the server pointer from smb_message. It can be passed down
from the caller to all places that need it.

(10) Don't need state locking in smb2_get_mid_entry() as we're just doing a
single read inside the lock. READ_ONCE() should suffice instead.

(11) Add a tracepoint to log EIO errors and up to a couple of bits of info
for each to make it easier to find out why an EIO error happened when
the system is very busy without introducing printk delays.

The patches can be found here also:

https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/log/?h=cifs-cleanup

Thanks,
David

Changes
=======
ver #4)
- Rebased on the ksmbd-for-next branch.
- The read tracepoint patch got merged, so drop it.
- Move the netfs_alloc, etc. patch first.
- Fix a couple of prototypes that need to be conditional (may need some post
cleanup).
- Fixed another couple of headers that needed their own prototype lists.
- Fixed #include order in a couple of places.

ver #3)
- Rebased on the ksmbd-for-next branch.
- Add the patches to clean up the function prototypes in the headers.
- Don't touch smbdirect.
- Put prototypes into netlink.h and cached_dir.h rather than
centralising them.
- Indent the arguments in the prototypes to the opening bracket + 1.
- Cleaned up most other checkpatch complaints.
- Added the EIO tracepoint patch to the end.

ver #2)
- Rebased on the ksmbd-for-next-next branch.
- Moved the patch to use netfs_alloc/free_folioq_buffer() down the stack.

David Howells (11):
cifs: Use netfs_alloc/free_folioq_buffer()
cifs: Do some preparation prior to organising the function
declarations
cifs: Clean up declarations
cifs: Rename mid_q_entry to smb_message
cifs: Remove the RFC1002 header from smb_hdr
cifs: Make smb1's SendReceive() wrap cifs_send_recv()
cifs: Clean up some places where an extra kvec[] was required for
rfc1002
cifs: Replace SendReceiveBlockingLock() with SendReceive() plus flags
cifs: Remove the server pointer from smb_message
cifs: Don't need state locking in smb2_get_mid_entry()
cifs: Add a tracepoint to log EIO errors

fs/smb/client/cached_dir.c | 2 +-
fs/smb/client/cached_dir.h | 37 +-
fs/smb/client/cifs_debug.c | 51 +-
fs/smb/client/cifs_debug.h | 15 +-
fs/smb/client/cifs_spnego.h | 2 -
fs/smb/client/cifs_swn.h | 15 +-
fs/smb/client/cifs_unicode.c | 1 +
fs/smb/client/cifs_unicode.h | 16 -
fs/smb/client/cifsacl.c | 11 +-
fs/smb/client/cifsencrypt.c | 83 +--
fs/smb/client/cifsfs.c | 36 +-
fs/smb/client/cifsfs.h | 64 --
fs/smb/client/cifsglob.h | 219 ++----
fs/smb/client/cifspdu.h | 13 +-
fs/smb/client/cifsproto.h | 1318 +++++++++++++++++----------------
fs/smb/client/cifssmb.c | 932 +++++++++++++----------
fs/smb/client/cifstransport.c | 439 ++---------
fs/smb/client/compress.c | 23 +-
fs/smb/client/compress.h | 20 +-
fs/smb/client/connect.c | 200 ++---
fs/smb/client/dfs.h | 12 +-
fs/smb/client/dfs_cache.h | 9 +-
fs/smb/client/dir.c | 9 +-
fs/smb/client/dns_resolve.h | 3 -
fs/smb/client/file.c | 7 +-
fs/smb/client/fs_context.c | 2 +-
fs/smb/client/fs_context.h | 9 -
fs/smb/client/fscache.h | 13 +-
fs/smb/client/inode.c | 15 +-
fs/smb/client/ioctl.c | 1 +
fs/smb/client/link.c | 11 +-
fs/smb/client/misc.c | 53 +-
fs/smb/client/netlink.h | 8 +-
fs/smb/client/netmisc.c | 21 +-
fs/smb/client/nterr.h | 2 -
fs/smb/client/ntlmssp.h | 13 -
fs/smb/client/readdir.c | 2 +-
fs/smb/client/reparse.c | 53 +-
fs/smb/client/reparse.h | 11 -
fs/smb/client/sess.c | 17 +-
fs/smb/client/smb1ops.c | 116 ++-
fs/smb/client/smb1proto.h | 227 ++++++
fs/smb/client/smb2file.c | 9 +-
fs/smb/client/smb2inode.c | 13 +-
fs/smb/client/smb2maperror.c | 6 +-
fs/smb/client/smb2misc.c | 11 +-
fs/smb/client/smb2ops.c | 253 +++----
fs/smb/client/smb2pdu.c | 230 +++---
fs/smb/client/smb2proto.h | 516 +++++++------
fs/smb/client/smb2transport.c | 113 ++-
fs/smb/client/smbdirect.c | 18 +-
fs/smb/client/smbdirect.h | 1 +
fs/smb/client/trace.h | 153 ++++
fs/smb/client/transport.c | 302 ++++----
fs/smb/client/xattr.c | 2 +-
fs/smb/common/smb2pdu.h | 3 -
fs/smb/common/smbglob.h | 1 -
57 files changed, 2887 insertions(+), 2855 deletions(-)
create mode 100644 fs/smb/client/smb1proto.h