smb: client: add support for WSL reparse points

Add support for creating special files via WSL reparse points when
using 'reparse=wsl' mount option. They're faster than NFS reparse
points because they don't require extra roundtrips to figure out what
->d_type a specific dirent is as such information is already stored in
query dir responses and then making getdents() calls faster.

Signed-off-by: Paulo Alcantara <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

smb: client: move most of reparse point handling code to common file

In preparation to add support for creating special files also via WSL
reparse points in next commits.

Signed-off-by: Paulo Alcantara <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

smb: client: reuse file lease key in compound operations

Currently, when a rename, unlink or set path size compound operation
is requested on a file that has a lot of dirty pages to be written
to the server, we do not send the lease key for these requests. As a
result, the server can assume that this request is from a new client, and
send a lease break notification to the same client, on the same
connection. As a response to the lease break, the client can consume
several credits to write the dirty pages to the server. Depending on the
server's credit grant implementation, the server can stop granting more
credits to this connection, and this can cause a deadlock (which can only
be resolved when the lease timer on the server expires).
One of the problems here is that the client is sending no lease key,
even if it has a lease for the file. This patch fixes the problem by
reusing the existing lease key on the file for rename, unlink and set path
size compound operations so that the client does not break its own lease.

A very trivial example could be a set of commands by a client that
maintains open handle (for write) to a file and then tries to copy the
contents of that file to another one, eg.,

tail -f /dev/null > myfile &
mv myfile myfile2

Presently, the network capture on the client shows that the move (or
rename) would trigger a lease break on the same client, for the same file.
With the lease key reused, the lease break request-response overhead is
eliminated, thereby reducing the roundtrips performed for this set of
operations.

The patch fixes the bug described above and also provides perf benefit.

Signed-off-by: Meetakshi Setiya <msetiya@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

cifs: commands that are retried should have replay flag set

MS-SMB2 states that the header flag SMB2_FLAGS_REPLAY_OPERATION
needs to be set when a command needs to be retried, so that
the server is aware that this is a replay for an operation that
appeared before.

This can be very important, for example, for state changing
operations and opens which get retried following a reconnect;
since the client maybe unaware of the status of the previous
open.

This is particularly important for multichannel scenario, since
disconnection of one connection does not mean that the session
is lost. The requests can be replayed on another channel.

This change also makes use of exponential back-off before replays
and also limits the number of retries to "retrans" mount option
value.

Also, this change does not modify the read/write codepath.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

smb: client: parse owner/group when creating reparse points

Parse owner/group when creating special files and symlinks under
SMB3.1.1 POSIX mounts.

Move the parsing of owner/group to smb2_compound_op() so we don't have
to duplicate it in both smb2_get_reparse_inode() and
smb311_posix_query_path_info().

Signed-off-by: Paulo Alcantara <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

cifs: Pass unbyteswapped eof value into SMB2_set_eof()

Change SMB2_set_eof() to take eof as CPU order rather than __le64 and pass
it directly rather than by pointer. This moves the conversion down into
SMB_set_eof() rather than all of its callers and means we don't need to
undo it for the traceline.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cifs@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>

smb: client: cleanup smb2_query_reparse_point()

Use smb2_compound_op() with SMB2_OP_GET_REPARSE to get reparse point.

Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

smb: client: fix hardlinking of reparse points

The client was sending an SMB2_CREATE request without setting
OPEN_REPARSE_POINT flag thus failing the entire hardlink operation.

Fix this by setting OPEN_REPARSE_POINT in create options for
SMB2_CREATE request when the source inode is a repase point.

Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

smb: client: fix renaming of reparse points

The client was sending an SMB2_CREATE request without setting
OPEN_REPARSE_POINT flag thus failing the entire rename operation.

Fix this by setting OPEN_REPARSE_POINT in create options for
SMB2_CREATE request when the source inode is a repase point.

Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

smb: client: allow creating special files via reparse points

Add support for creating special files (e.g. char/block devices,
sockets, fifos) via NFS reparse points on SMB2+, which are fully
supported by most SMB servers and documented in MS-FSCC.

smb2_get_reparse_inode() creates the file with a corresponding reparse
point buffer set in @iov through a single roundtrip to the server.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202311260746.HOJ039BV-lkp@intel.com/
Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

smb: client: fix potential OOBs in smb2_parse_contexts()

Validate offsets and lengths before dereferencing create contexts in
smb2_parse_contexts().

This fixes following oops when accessing invalid create contexts from
server:

BUG: unable to handle page fault for address: ffff8881178d8cc3
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 4a01067 P4D 4a01067 PUD 0
Oops: 0000 [#1] PREEMPT SMP NOPTI
CPU: 3 PID: 1736 Comm: mount.cifs Not tainted 6.7.0-rc4 #1
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014
RIP: 0010:smb2_parse_contexts+0xa0/0x3a0 [cifs]
Code: f8 10 75 13 48 b8 93 ad 25 50 9c b4 11 e7 49 39 06 0f 84 d2 00
00 00 8b 45 00 85 c0 74 61 41 29 c5 48 01 c5 41 83 fd 0f 76 55 <0f> b7
7d 04 0f b7 45 06 4c 8d 74 3d 00 66 83 f8 04 75 bc ba 04 00
RSP: 0018:ffffc900007939e0 EFLAGS: 00010216
RAX: ffffc90000793c78 RBX: ffff8880180cc000 RCX: ffffc90000793c90
RDX: ffffc90000793cc0 RSI: ffff8880178d8cc0 RDI: ffff8880180cc000
RBP: ffff8881178d8cbf R08: ffffc90000793c22 R09: 0000000000000000
R10: ffff8880180cc000 R11: 0000000000000024 R12: 0000000000000000
R13: 0000000000000020 R14: 0000000000000000 R15: ffffc90000793c22
FS: 00007f873753cbc0(0000) GS:ffff88806bc00000(0000)
knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff8881178d8cc3 CR3: 00000000181ca000 CR4: 0000000000750ef0
PKRU: 55555554
Call Trace:
<TASK>
? __die+0x23/0x70
? page_fault_oops+0x181/0x480
? search_module_extables+0x19/0x60
? srso_alias_return_thunk+0x5/0xfbef5
? exc_page_fault+0x1b6/0x1c0
? asm_exc_page_fault+0x26/0x30
? smb2_parse_contexts+0xa0/0x3a0 [cifs]
SMB2_open+0x38d/0x5f0 [cifs]
? smb2_is_path_accessible+0x138/0x260 [cifs]
smb2_is_path_accessible+0x138/0x260 [cifs]
cifs_is_path_remote+0x8d/0x230 [cifs]
cifs_mount+0x7e/0x350 [cifs]
cifs_smb3_do_mount+0x128/0x780 [cifs]
smb3_get_tree+0xd9/0x290 [cifs]
vfs_get_tree+0x2c/0x100
? capable+0x37/0x70
path_mount+0x2d7/0xb80
? srso_alias_return_thunk+0x5/0xfbef5
? _raw_spin_unlock_irqrestore+0x44/0x60
__x64_sys_mount+0x11a/0x150
do_syscall_64+0x47/0xf0
entry_SYSCALL_64_after_hwframe+0x6f/0x77
RIP: 0033:0x7f8737657b1e

Reported-by: Robert Morris <rtm@csail.mit.edu>
Cc: stable@vger.kernel.org
Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

smb: client: move some params to cifs_open_info_data

Instead of passing @adjust_tz and some reparse point related fields as
parameters in ->query_path_info() and
{smb311_posix,cifs}_info_to_fattr() calls, move them to
cifs_open_info_data structure as they can be easily accessed through
@data.

No functional changes.

Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

smb: move client and server files to common directory fs/smb

Move CIFS/SMB3 related client and server files (cifs.ko and ksmbd.ko
and helper modules) to new fs/smb subdirectory:

fs/cifs --> fs/smb/client
fs/ksmbd --> fs/smb/server
fs/smbfs_common --> fs/smb/common

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>