When compiling with W=1 I noticed various functions that
did not follow proper style in describing (in the comments)
the parameters passed in to the function. For example:

fs/cifs/inode.c:2236: warning: Function parameter or member 'mode' not described in 'cifs_wait_bit_killable'

I did not address the style warnings in two of the six files
(connect.c and misc.c) in order to reduce risk of merge
conflict with pending patches. We can update those later.
Signed-off-by: Steve French <stfrench@microsoft.com>

Some witness notifications, like client move, tell the client to
reconnect to a specific IP address. In this situation the DFS failover
code path has to be skipped so clean up as much as possible the
cifs_reconnect() code.
Signed-off-by: Samuel Cabrero <scabrero@suse.de>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

If the daemon starts after mounting a share, or if it crashes, this
provides a mechanism to register again.
Signed-off-by: Samuel Cabrero <scabrero@suse.de>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

+ Indicate if witness feature is supported
+ Indicate if witness is used when dumping tcons
+ Dumps witness registrations. Example:
  Witness registrations:
  Id: 1 Refs: 1 Network name: 'fs.fover.ad'(y) Share name: 'share1'(y) \
    Ip address: 192.168.103.200(n)
Signed-off-by: Samuel Cabrero <scabrero@suse.de>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

+ Set a handler for the witness notification messages received from the
  userspace daemon.

+ Handle the resource state change notification. When the resource
  becomes unavailable or available set the tcp status to
  CifsNeedReconnect for all channels.
Signed-off-by: Samuel Cabrero <scabrero@suse.de>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

+ Define the generic netlink family commands and message attributes to
  communicate with the userspace daemon

+ The register and unregister commands are sent when connecting or
  disconnecting a tree. The witness registration keeps a pointer to
  the tcon and has the same lifetime.

+ Each registration has an id allocated by an IDR. This id is sent to the
  userspace daemon in the register command, and will be included in the
  notification messages from the userspace daemon to retrieve from the
  IDR the matching registration.

+ The authentication information is bundled in the register message.
  If kerberos is used the message just carries a flag.
Signed-off-by: Samuel Cabrero <scabrero@suse.de>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

Correct references to fs/cifs/README which has been replaced by
Documentation/filesystems/admin-guide/cifs/usage.rst, and also
correct a typo.
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

Add 'witness' mount option to register for witness notifications.
Signed-off-by: Samuel Cabrero <scabrero@suse.de>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

Register a new generic netlink family to talk to the witness service
userspace daemon.
Signed-off-by: Samuel Cabrero <scabrero@suse.de>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

misc.c was getting a little large, move two of the UNC parsing relating
functions to a new C file unc.c which makes the coding of the
upcoming witness protocol patch series a little cleaner as well.
Suggested-by: Rafal Szczesniak <rafal@elbingbrewery.org>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

Trivial fix for a few comments which didn't follow kernel style
Signed-off-by: Steve French <stfrench@microsoft.com>

Move the function to misc.c
Signed-off-by: Samuel Cabrero <scabrero@suse.de>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

Move the function to misc.c and give it a public header.
Signed-off-by: Samuel Cabrero <scabrero@suse.de>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

as we now have a full smb3_fs_context as part of the cifs superblock
we no longer need a local copy of the mount options and can just
reference the copy in the smb3_fs_context.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

and populate it during mount in cifs_smb3_do_mount()
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

none of the callers use this argument any more.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

See Documentation/filesystems/mount_api.rst for details on new mount API
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

Also rename the function from cifs_ to smb3_
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

No change to logic, just moving the enum of cifs mount parms into a header
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

Continue restructuring needed for support of new mount API
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

Harmonize and change all such variables to 'ctx', where possible.
No changes to actual logic.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

In the negotiate protocol preauth context, the server is not required
to populate the salt (although it is done by most servers) so do
not warn on mount.

We retain the checks (warn) that the preauth context is the minimum
size and that the salt does not exceed DataLength of the SMB response.
Although we use the defaults in the case that the preauth context
response is invalid, these checks may be useful in the future
as servers add support for additional mechanisms.

CC: Stable <stable@vger.kernel.org>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

Trivial changes to clarify confusing comment about
SPNEGO blog (and also one length comparisons in negotiate
context parsing).
Suggested-by: Tom Talpey <tom@talpey.com>
Suggested-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

For the cifsacl mount option, we did not support sticky bits.
With this patch, we do support it, by setting the DELETE_CHILD perm
on the directory only for the owner user. When sticky bit is not
enabled, allow DELETE_CHILD perm for everyone.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

With the "cifsacl" mount option, the mode bits set on the file/dir
is converted to corresponding ACEs in DACL. However, only the
ALLOWED ACEs were being set for "owner" and "group" SIDs. Since
owner is a subset of group, and group is a subset of
everyone/world SID, in order to properly emulate unix perm groups,
we need to add DENIED ACEs. If we don't do that, "owner" and "group"
SIDs could get more access rights than they should. Which is what
was happening. This fixes it.

We try to keep the "preferred" order of ACEs, i.e. DENYs followed
by ALLOWs. However, for a small subset of cases we cannot
maintain the preferred order. In that case, we'll end up with the
DENY ACE for group after the ALLOW for the owner.

If owner SID == group SID, use the more restrictive
among the two perm bits and convert them to ACEs.

Also, for reverse mapping, i.e. to convert ACL to unix perm bits,
for the "others" bits, we needed to add the masked bits of the
owner and group masks to others mask.

Updated version of patch fixes a problem noted by the kernel
test robot.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

Azure does not send an SPNEGO blob in the negotiate protocol response,
so we shouldn't assume that it is there when validating the location
of the first negotiate context.  This avoids the potential confusing
mount warning:

   CIFS: Invalid negotiate context offset

CC: Stable <stable@vger.kernel.org>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

Mounts to Azure cause an unneeded warning message in dmesg
   "CIFS: VFS: parse_server_interfaces: incomplete interface info"

Azure rounds up the size (by 8 additional bytes, to a
16 byte boundary) of the structure returned on the query
of the server interfaces at mount time.  This is permissible
even though different than other servers so do not log a warning
if query network interfaces response is only rounded up by 8
bytes or fewer.

CC: Stable <stable@vger.kernel.org>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

In preparation to enable -Wimplicit-fallthrough for Clang, fix multiple
warnings by explicitly adding multiple break/goto statements instead of
just letting the code fall through to the next case.

Link: https://github.com/KSPP/linux/issues/115Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

Pull x86 fixes from Thomas Gleixner:
 "A set of x86 and membarrier fixes:

   - Correct a few problems in the x86 and the generic membarrier
     implementation. Small corrections for assumptions about visibility
     which have turned out not to be true.

   - Make the PAT bits for memory encryption correct vs 4K and 2M/1G
     page table entries as they are at a different location.

   - Fix a concurrency issue in the the local bandwidth readout of
     resource control leading to incorrect values

   - Fix the ordering of allocating a vector for an interrupt. The order
     missed to respect the provided cpumask when the first attempt of
     allocating node local in the mask fails. It then tries the node
     instead of trying the full provided mask first. This leads to
     erroneous error messages and breaking the (user) supplied affinity
     request. Reorder it.

   - Make the INT3 padding detection in optprobe work correctly"

* tag 'x86-urgent-2020-12-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/kprobes: Fix optprobe to detect INT3 padding correctly
  x86/apic/vector: Fix ordering in vector assignment
  x86/resctrl: Fix incorrect local bandwidth when mba_sc is enabled
  x86/mm/mem_encrypt: Fix definition of PMD_FLAGS_DEC_WP
  membarrier: Execute SYNC_CORE on the calling thread
  membarrier: Explicitly sync remote cores when SYNC_CORE is requested
  membarrier: Add an actual barrier before rseq_preempt()
  x86/membarrier: Get rid of a dubious optimization

Pull block fixes from Jens Axboe:
 "This should be it for 5.10.

  Mike and Song looked into the warning case, and thankfully it appears
  the fix was pretty trivial - we can just change the md device chunk
  type to unsigned int to get rid of it. They cannot currently be < 0,
  and nobody is checking for that either.

  We're reverting the discard changes as the corruption reports came in
  very late, and there's just no time to attempt to deal with it at this
  point. Reverting the changes in question is the right call for 5.10"

* tag 'block-5.10-2020-12-12' of git://git.kernel.dk/linux-block:
  md: change mddev 'chunk_sectors' from int to unsigned
  Revert "md: add md_submit_discard_bio() for submitting discard bio"
  Revert "md/raid10: extend r10bio devs to raid disks"
  Revert "md/raid10: pull codes that wait for blocked dev into one function"
  Revert "md/raid10: improve raid10 discard request"
  Revert "md/raid10: improve discard request for far layout"
  Revert "dm raid: remove unnecessary discard limits for raid10"

Pull SCSI fixes from James Bottomley:
 "Five small fixes.  Four in drivers:

   - hisi_sas: fix internal queue timeout

   - be2iscsi: revert a prior fix causing problems

   - bnx2i: add missing dependency

   - storvsc: late arriving revert of a problem fix

  and one in the core.

  The core one is a minor change to stop paying attention to the busy
  count when returning out of resources because there's a race window
  where the queue might not restart due to missing returning I/O"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  Revert "scsi: storvsc: Validate length of incoming packet in storvsc_on_channel_callback()"
  scsi: hisi_sas: Select a suitable queue for internal I/Os
  scsi: core: Fix race between handling STS_RESOURCE and completion
  scsi: be2iscsi: Revert "Fix a theoretical leak in beiscsi_create_eqs()"
  scsi: bnx2i: Requires MMU

Pull i2c fix from Wolfram Sang:
 "Bugfix for the AT24 EEPROM driver"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  misc: eeprom: at24: fix NVMEM name with custom AT24 device name

Pull kvm fixes from Paolo Bonzini:
 "Bugfixes for ARM, x86 and tools"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  tools/kvm_stat: Exempt time-based counters
  KVM: mmu: Fix SPTE encoding of MMIO generation upper half
  kvm: x86/mmu: Use cpuid to determine max gfn
  kvm: svm: de-allocate svm_cpu_data for all cpus in svm_cpu_uninit()
  selftests: kvm/set_memory_region_test: Fix race in move region test
  KVM: arm64: Add usage of stage 2 fault lookup level in user_mem_abort()
  KVM: arm64: Fix handling of merging tables into a block entry
  KVM: arm64: Fix memory leak on stage2 update of a valid PTE

Pull xen fixes from Juergen Gross:
 "A short series fixing a regression introduced in 5.9 for running as
  Xen dom0 on a system with NVMe backed storage"

* tag 'for-linus-5.10c-rc8-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen: don't use page->lru for ZONE_DEVICE memory
  xen: add helpers for caching grant mapping pages

Pull RISC-V fix from Palmer Dabbelt:
 "Just one fix. It's nothing critical, just a randconfig that wasn't
  building. That said, it does seem pretty safe and is technically a
  regression so I'm sending it along for 5.10:

   - define get_cycles64() all the time, as it's used by most
     configurations"

* tag 'riscv-for-linus-5.10-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  RISC-V: Define get_cycles64() regardless of M-mode

Pull io_uring fixes from Jens Axboe:
 "Two fixes in here, fixing issues introduced in this merge window"

* tag 'io_uring-5.10-2020-12-11' of git://git.kernel.dk/linux-block:
  io_uring: fix file leak on error path of io ctx creation
  io_uring: fix mis-seting personality's creds

Pull input fixes from Dmitry Torokhov:

 - a fix for cm109 stomping on its own control URB if it tries to toggle
   buzzer immediately after userspace opens input device (found by
   syzcaller)

 - another fix for Raydium touchscreens that do not like splitting
   command transfers

 - quirks for i8042, soc_button_array, and goodix drivers to make them
   work better with certain hardware.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: goodix - add upside-down quirk for Teclast X98 Pro tablet
  Input: cm109 - do not stomp on control URB
  Input: i8042 - add Acer laptops to the i8042 reset list
  Input: cros_ec_keyb - send 'scancodes' in addition to key events
  Input: soc_button_array - add Lenovo Yoga Tablet2 1051L to the dmi_use_low_level_irq list
  Input: raydium_ts_i2c - do not split tx transactions

Commit e2782f56 ("Revert "dm raid: remove unnecessary discard
limits for raid10"") exposed compiler warnings introduced by commit
e0910c8e ("dm raid: fix discard limits for raid1 and raid10"):

In file included from ./include/linux/kernel.h:14,
                 from ./include/asm-generic/bug.h:20,
                 from ./arch/x86/include/asm/bug.h:93,
                 from ./include/linux/bug.h:5,
                 from ./include/linux/mmdebug.h:5,
                 from ./include/linux/gfp.h:5,
                 from ./include/linux/slab.h:15,
                 from drivers/md/dm-raid.c:8:
drivers/md/dm-raid.c: In function ‘raid_io_hints’:
./include/linux/minmax.h:18:28: warning: comparison of distinct pointer types lacks a cast
  (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
                            ^~
./include/linux/minmax.h:32:4: note: in expansion of macro ‘__typecheck’
   (__typecheck(x, y) && __no_side_effects(x, y))
    ^~~~~~~~~~~
./include/linux/minmax.h:42:24: note: in expansion of macro ‘__safe_cmp’
  __builtin_choose_expr(__safe_cmp(x, y), \
                        ^~~~~~~~~~
./include/linux/minmax.h:51:19: note: in expansion of macro ‘__careful_cmp’
 #define min(x, y) __careful_cmp(x, y, <)
                   ^~~~~~~~~~~~~
./include/linux/minmax.h:84:39: note: in expansion of macro ‘min’
  __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); })
                                       ^~~
drivers/md/dm-raid.c:3739:33: note: in expansion of macro ‘min_not_zero’
   limits->max_discard_sectors = min_not_zero(rs->md.chunk_sectors,
                                 ^~~~~~~~~~~~

Fix this by changing the chunk_sectors member of 'struct mddev' from
int to 'unsigned int' to match the type used for the 'chunk_sectors'
member of 'struct queue_limits'.  Various MD code still uses 'int' but
none of it appears to ever make use of signed int; and storing
positive signed int in unsigned is perfectly safe.
Reported-by: Song Liu <songliubraving@fb.com>
Fixes: e2782f56 ("Revert "dm raid: remove unnecessary discard limits for raid10"")
Fixes: e0910c8e ("dm raid: fix discard limits for raid1 and raid10")
Cc: stable@vger,kernel.org # e0910c8e was marked for stable@
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Commit

  7705dc85 ("x86/vmlinux: Use INT3 instead of NOP for linker fill bytes")

changed the padding bytes between functions from NOP to INT3. However,
when optprobe decodes a target function it finds INT3 and gives up the
jump optimization.

Instead of giving up any INT3 detection, check whether the rest of the
bytes to the end of the function are INT3. If all of them are INT3,
those come from the linker. In that case, continue the optprobe jump
optimization.

 [ bp: Massage commit message. ]

Fixes: 7705dc85 ("x86/vmlinux: Use INT3 instead of NOP for linker fill bytes")
Reported-by: Adam Zabrocki <pi3@pi3.com.pl>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/160767025681.3880685.16021570341428835411.stgit@devnote2