Commit Graph

21 Commits

Author SHA1 Message Date
Steve French 68e14569d7 smb3: add dynamic trace points for tree disconnect
Needed this for debugging a failing xfstest.
Also change camel case for "treeName" to "tree_name" in tcon struct.

Example trace output (from "trace-cmd record -e smb3_tdis*"):
          umount-9718    [006] .....  5909.780244: smb3_tdis_enter: xid=206 sid=0xcf38894e tid=0x3d0b8cf8 path=\\localhost\test
          umount-9718    [007] .....  5909.780878: smb3_tdis_done: xid=206 sid=0xcf38894e tid=0x3d0b8cf8

Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-10-05 01:31:18 -05:00
Vincent Whitchurch cc391b694f cifs: fix potential deadlock in direct reclaim
The srv_mutex is used during writeback so cifs should ensure that
allocations done when that mutex is held are done with GFP_NOFS, to
avoid having direct reclaim ending up waiting for the same mutex and
causing a deadlock.  This is detected by lockdep with the splat below:

 ======================================================
 WARNING: possible circular locking dependency detected
 5.18.0 #70 Not tainted
 ------------------------------------------------------
 kswapd0/49 is trying to acquire lock:
 ffff8880195782e0 (&tcp_ses->srv_mutex){+.+.}-{3:3}, at: compound_send_recv

 but task is already holding lock:
 ffffffffa98e66c0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -> #1 (fs_reclaim){+.+.}-{0:0}:
        fs_reclaim_acquire
        kmem_cache_alloc_trace
        __request_module
        crypto_alg_mod_lookup
        crypto_alloc_tfm_node
        crypto_alloc_shash
        cifs_alloc_hash
        smb311_crypto_shash_allocate
        smb311_update_preauth_hash
        compound_send_recv
        cifs_send_recv
        SMB2_negotiate
        smb2_negotiate
        cifs_negotiate_protocol
        cifs_get_smb_ses
        cifs_mount
        cifs_smb3_do_mount
        smb3_get_tree
        vfs_get_tree
        path_mount
        __x64_sys_mount
        do_syscall_64
        entry_SYSCALL_64_after_hwframe

 -> #0 (&tcp_ses->srv_mutex){+.+.}-{3:3}:
        __lock_acquire
        lock_acquire
        __mutex_lock
        mutex_lock_nested
        compound_send_recv
        cifs_send_recv
        SMB2_write
        smb2_sync_write
        cifs_write
        cifs_writepage_locked
        cifs_writepage
        shrink_page_list
        shrink_lruvec
        shrink_node
        balance_pgdat
        kswapd
        kthread
        ret_from_fork

 other info that might help us debug this:

  Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(fs_reclaim);
                                lock(&tcp_ses->srv_mutex);
                                lock(fs_reclaim);
   lock(&tcp_ses->srv_mutex);

  *** DEADLOCK ***

 1 lock held by kswapd0/49:
  #0: ffffffffa98e66c0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat

 stack backtrace:
 CPU: 2 PID: 49 Comm: kswapd0 Not tainted 5.18.0 #70
 Call Trace:
  <TASK>
  dump_stack_lvl
  dump_stack
  print_circular_bug.cold
  check_noncircular
  __lock_acquire
  lock_acquire
  __mutex_lock
  mutex_lock_nested
  compound_send_recv
  cifs_send_recv
  SMB2_write
  smb2_sync_write
  cifs_write
  cifs_writepage_locked
  cifs_writepage
  shrink_page_list
  shrink_lruvec
  shrink_node
  balance_pgdat
  kswapd
  kthread
  ret_from_fork
  </TASK>

Fix this by using the memalloc_nofs_save/restore APIs around the places
where the srv_mutex is held.  Do this in a wrapper function for the
lock/unlock of the srv_mutex, and rename the srv_mutex to avoid missing
call sites in the conversion.

Note that there is another lockdep warning involving internal crypto
locks, which was masked by this problem and is visible after this fix,
see the discussion in this thread:

 https://lore.kernel.org/all/20220523123755.GA13668@axis.com/

Link: https://lore.kernel.org/r/CANT5p=rqcYfYMVHirqvdnnca4Mo+JQSw5Qu12v=kPfpk5yhhmg@mail.gmail.com/
Reported-by: Shyam Prasad N <nspmangalore@gmail.com>
Suggested-by: Lars Persson <larper@axis.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-06-01 00:03:18 -05:00
Shyam Prasad N dca65818c8 cifs: use a different reconnect helper for non-cifsd threads
The cifs_demultiplexer_thread should only call cifs_reconnect.
If any other thread wants to trigger a reconnect, they can do
so by updating the server tcpStatus to CifsNeedReconnect.

The last patch attempted to use the same helper function for
both types of threads, but that causes other issues
with lock dependencies.

This patch creates a new helper for non-cifsd threads, that
will indicate to cifsd that the server needs reconnect.

Fixes: 2a05137a05 ("cifs: mark sessions for reconnection in helper function")
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-03-18 23:12:03 -05:00
Shyam Prasad N 52492ff5c5 cifs: call helper functions for marking channels for reconnect
cifs_mark_tcp_ses_conns_for_reconnect helper function is now
meant to be used by any of the threads to mark a channel
(or all the channels) for reconnect.

Replace all such manual changes to tcpStatus to use this
helper function, which takes care that the right channels,
smb sessions and tcons are marked for reconnect.

Also includes one line minor change
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>
2022-02-08 22:13:48 -06:00
Shyam Prasad N ba978e8325 cifs: cifs_ses_mark_for_reconnect should also update reconnect bits
Recent restructuring of cifs_reconnect introduced a helper func
named cifs_ses_mark_for_reconnect, which updates the state of tcp
session for all the channels of a session for reconnect.

However, this does not update the session state and chans_need_reconnect
bitmask. This change fixes that.

Also, cifs_mark_tcp_sess_for_reconnect should mark set the bitmask
for all channels when the whole session is marked for reconnect.
Fixed that here too.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-01-19 11:10:58 -06:00
Shyam Prasad N 080dc5e565 cifs: take cifs_tcp_ses_lock for status checks
While checking/updating status for tcp ses, smb ses or tcon,
we take GlobalMid_Lock. This doesn't make any sense.
Replaced it with cifs_tcp_ses_lock.

Ideally, we should take a spin lock per struct.
But since tcp ses, smb ses and tcon objects won't add up to a lot,
I think there should not be too much contention.

Also, in few other places, these are checked without locking.
Added locking for these.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-01-07 20:07:07 -06:00
Paulo Alcantara 8ae87bbeb5 cifs: introduce cifs_ses_mark_for_reconnect() helper
Use new cifs_ses_mark_for_reconnect() helper to mark all session
channels for reconnect instead of duplicating it in different places.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-11-16 10:57:08 -06:00
Ronnie Sahlberg 76a3c92ec9 cifs: remove support for NTLM and weaker authentication algorithms
for SMB1.
This removes the dependency to DES.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-08-25 15:47:06 -05:00
Steve French ff93b71a3e smb3: fix uninitialized value for port in witness protocol move
Although in practice this can not occur (since IPv4 and IPv6 are the
only two cases currently supported), it is cleaner to avoid uninitialized
variable warnings.

Addresses smatch warning:
  fs/cifs/cifs_swn.c:468 cifs_swn_store_swn_addr() error: uninitialized symbol 'port'.

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
CC: Samuel Cabrero <scabrero@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-06-20 21:28:17 -05:00
Liu xuzhi 403dba003d fs/cifs/: fix misspellings using codespell tool
A typo is found out by codespell tool in 251th lines of cifs_swn.c:

$ codespell ./fs/cifs/
./cifs_swn.c:251: funciton  ==> function

Fix a typo found by codespell.

Signed-off-by: Liu xuzhi <liu.xuzhi@zte.com.cn>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-03-19 00:37:51 -05:00
YueHaibing af982da9a6 cifs: Fix inconsistent IS_ERR and PTR_ERR
Fix inconsistent IS_ERR and PTR_ERR in cifs_find_swn_reg(). The proper
pointer to be passed as argument to PTR_ERR() is share_name.

This bug was detected with the help of Coccinelle.

Fixes: bf80e5d425 ("cifs: Send witness register and unregister commands to userspace daemon")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Samuel Cabrero <scabrero@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-02-19 21:29:10 -06:00
Dan Carpenter 0f2c66ae5c cifs: Re-indent cifs_swn_reconnect()
This code is slightly nicer if we flip the cifs_sockaddr_equal()
around and pull all the code in one tab.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Samuel Cabrero <scabrero@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-18 00:02:37 -06:00
Dan Carpenter eedf8e88e5 cifs: Unlock on errors in cifs_swn_reconnect()
There are three error paths which need to unlock before returning.

Fixes: 121d947d4f ("cifs: Handle witness client move notification")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Samuel Cabrero <scabrero@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-18 00:02:28 -06:00
Dan Carpenter 6a29ab57f4 cifs: Delete a stray unlock in cifs_swn_reconnect()
The unlock is done in the caller, this is a stray which leads to a
double unlock bug.

Fixes: bf80e5d425 ("cifs: Send witness register and unregister commands to userspace daemon")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Samuel Cabrero <scabrero@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-18 00:02:16 -06:00
Linus Torvalds e13300bdaa cifs/smb3 changes, the largest part are for support of the newer mount API, also includes addition of support for the SMB3 witness protocol which can provide important notifications from the server on address or export or network changes, and three patches for stable
-----BEGIN PGP SIGNATURE-----
 
 iQGzBAABCgAdFiEE6fsu8pdIjtWE/DpLiiy9cAdyT1EFAl/bxgoACgkQiiy9cAdy
 T1HrVwv9E3lSCo8xvipqU4vto+I/29zVa7yjf2oY06LyHkgXEBzPYjhWtLN3KyF+
 H6gnFUusyw4prteeFXUYatXYBhT3tK1fxeshUT7B+zk9eFGQca8WYockjEIiDci3
 WcieEHH1xvDuwyPAomjpJFEQ70h+vXBREvtLZOAPxisKID+gKjncP0jncAFeFvhM
 Cln/s88YmG7vJZ78S1yIJqiD0PvUJOdYLrDz/Zmwh+m5UIs9N9clB1MVuLw+5vMe
 E5vG6Aeh3hCvwyVmGxTx4IEixV9hFR20XBvxTSnhyGQ4s+7DfcHmDDcmPHEnTcZ8
 7U2Y1xUslx6nvoej9hlZDB1bEyMPNlI6GIYjDb6RiU18D3crgygat4SmgbPUV1up
 P6hqIy1NebskZjLEpVDIDNV7JWqucHzfJYfPW9B/LwiH72KMNhwQhZ9H1PqkzS7q
 WCeVKdc5vGhLyHEZJjHu3qOhCQQQ3cDh4akL5gWiYmwNDGQZjpVfhE4tzcMYWtSn
 WkxqLVA3
 =YiLC
 -----END PGP SIGNATURE-----

Merge tag '5.11-rc-smb3' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs updates from Steve French:
 "The largest part are for support of the newer mount API which has been
  needed for cifs/smb3 mounts for a long time due to the new API's
  better handling of remount, and better error reporting. There are
  three additional small cleanup patches for this being tested, that are
  not included yet.

  This series also includes addition of support for the SMB3 witness
  protocol which can provide important notifications from the server to
  client on server address or export or network changes. This can be
  useful for example in order to be notified before the failure - when a
  server's IP address changes (in the future it will allow us to support
  server notifications of when a share is moved).

  It also includes three patches for stable e.g. some that better handle
  some confusing error messages during session establishment"

* tag '5.11-rc-smb3' of git://git.samba.org/sfrench/cifs-2.6: (55 commits)
  cifs: update internal module version number
  cifs: Fix support for remount when not changing rsize/wsize
  cifs: handle "guest" mount parameter
  cifs: correct four aliased mount parms to allow use of previous names
  cifs: Tracepoints and logs for tracing credit changes.
  cifs: fix use after free in cifs_smb3_do_mount()
  cifs: fix rsize/wsize to be negotiated values
  cifs: Fix some error pointers handling detected by static checker
  smb3: remind users that witness protocol is experimental
  cifs: update super_operations to show_devname
  cifs: fix uninitialized variable in smb3_fs_context_parse_param
  cifs: update mnt_cifs_flags during reconfigure
  cifs: move update of flags into a separate function
  cifs: remove ctx argument from cifs_setup_cifs_sb
  cifs: do not allow changing posix_paths during remount
  cifs: uncomplicate printing the iocharset parameter
  cifs: don't create a temp nls in cifs_setup_ipc
  cifs: simplify handling of cifs_sb/ctx->local_nls
  cifs: we do not allow changing username/password/unc/... during remount
  cifs: add initial reconfigure support
  ...
2020-12-17 17:41:37 -08:00
Samuel Cabrero 09a8361e3b cifs: Fix some error pointers handling detected by static checker
* extract_hostname() and extract_sharename() never return NULL, so
  use IS_ERR() instead of IS_ERR_OR_NULL() in cifs_find_swn_reg(). If
  any of these functions return an error, then return an error pointer
  instead of NULL.
* Change cifs_find_swn_reg() function to always return a valid pointer
  or an error pointer, instead of returning NULL if the registration
  is not found.
* Finally update cifs_find_swn_reg() callers to check for -EEXIST
  instead of NULL.
* In cifs_get_swn_reg() the swnreg idr mutex was not unlocked in the
  error path of cifs_find_swn_reg() call.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Samuel Cabrero <scabrero@suse.de>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-15 15:13:47 -06:00
Samuel Cabrero 121d947d4f cifs: Handle witness client move notification
This message is sent to tell a client to close its current connection
and connect to the specified address.

Signed-off-by: Samuel Cabrero <scabrero@suse.de>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-14 09:18:55 -06:00
Samuel Cabrero 21077c62e1 cifs: Send witness register messages to userspace daemon in echo task
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>
2020-12-14 09:16:23 -06:00
Samuel Cabrero 20fab0da2f cifs: Add witness information to debug data dump
+ 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>
2020-12-14 09:16:22 -06:00
Samuel Cabrero fed979a7e0 cifs: Set witness notification handler for messages from userspace daemon
+ 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>
2020-12-14 09:16:22 -06:00
Samuel Cabrero bf80e5d425 cifs: Send witness register and unregister commands to userspace daemon
+ 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>
2020-12-14 09:16:22 -06:00