Граф коммитов

56 Коммитов

Автор SHA1 Сообщение Дата
Shyam Prasad N d7d7a66aac cifs: avoid use of global locks for high contention data
During analysis of multichannel perf, it was seen that
the global locks cifs_tcp_ses_lock and GlobalMid_Lock, which
were shared between various data structures were causing a
lot of contention points.

With this change, we're breaking down the use of these locks
by introducing new locks at more granular levels. i.e.
server->srv_lock, ses->ses_lock and tcon->tc_lock to protect
the unprotected fields of server, session and tcon structs;
and server->mid_lock to protect mid related lists and entries
at server level.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-08-01 01:34:45 -05:00
Steve French ee3c8019cc cifs: fix uninitialized pointer in error case in dfs_cache_get_tgt_share
Set default value of ppath to null.

Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-06-04 13:33:42 -05:00
Paulo Alcantara ef605e8682 cifs: skip trailing separators of prefix paths
During DFS failover, prefix paths may change, so make sure to not
leave trailing separators when parsing thew in
dfs_cache_get_tgt_share().  The separators of prefix paths are already
handled by build_path_from_dentry_optional_prefix().

Consider the following DFS link:

  //dom/dfs/link: [\srv1\share\dir1, \srv2\share\dir1]

Before commit:

  mount.cifs //dom/dfs/link
  tree connect to \\srv1\share; prefix_path=dir1
  disconnect srv1; failover to srv2
  tree connect to \\srv2\share; prefix_path=dir1\
  mv foo bar

  ...
  SMB2 430 Create Request File: dir1\\foo;GetInfo Request FILE_INFO/SMB2_FILE_ALL_INFO;Close Request
  SMB2 582 Create Response File: dir1\\foo;GetInfo Response;Close Response
  SMB2 430 Create Request File: dir1\\bar;GetInfo Request FILE_INFO/SMB2_FILE_ALL_INFO;Close Request
  SMB2 286 Create Response, Error: STATUS_OBJECT_NAME_NOT_FOUND;GetInfo Response, Error: STATUS_OBJECT_NAME_NOT_FOUND;Close Response, Error: STATUS_OBJECT_NAME_NOT_FOUND
  SMB2 462 Create Request File: dir1\\foo;SetInfo Request FILE_INFO/SMB2_FILE_RENAME_INFO NewName:dir1\\bar;Close Request
  SMB2 478 Create Response File: dir1\\foo;SetInfo Response, Error: STATUS_OBJECT_NAME_INVALID;Close Response

After commit:

  mount.cifs //dom/dfs/link
  tree connect to \\srv1\share; prefix_path=dir1
  disconnect srv1; failover to srv2
  tree connect to \\srv2\share; prefix_path=dir1
  mv foo bar

  ...
  SMB2 430 Create Request File: dir1\foo;GetInfo Request FILE_INFO/SMB2_FILE_ALL_INFO;Close Request
  SMB2 582 Create Response File: dir1\foo;GetInfo Response;Close Response
  SMB2 430 Create Request File: dir1\bar;GetInfo Request FILE_INFO/SMB2_FILE_ALL_INFO;Close Request
  SMB2 286 Create Response, Error: STATUS_OBJECT_NAME_NOT_FOUND;GetInfo Response, Error: STATUS_OBJECT_NAME_NOT_FOUND;Close Response, Error: STATUS_OBJECT_NAME_NOT_FOUND
  SMB2 462 Create Request File: dir1\foo;SetInfo Request FILE_INFO/SMB2_FILE_RENAME_INFO NewName:dir1\bar;Close Request
  SMB2 478 Create Response File: dir1\foo;SetInfo Response;Close Response

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-06-03 14:14:58 -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
Enzo Matsumiya 337b8b0e43 cifs: return ENOENT for DFS lookup_cache_entry()
EEXIST didn't make sense to use when dfs_cache_find() couldn't find a
cache entry nor retrieve a referral target.

It also doesn't make sense cifs_dfs_query_info_nonascii_quirk() to
emulate ENOENT anymore.

Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-05-20 17:44:34 -05:00
Paulo Alcantara 41f10081a9 cifs: fix NULL ptr dereference in refresh_mounts()
Either mount(2) or automount might not have server->origin_fullpath
set yet while refresh_cache_worker() is attempting to refresh DFS
referrals.  Add missing NULL check and locking around it.

This fixes bellow crash:

[ 1070.276835] general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN NOPTI
[ 1070.277676] KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
[ 1070.278219] CPU: 1 PID: 8506 Comm: kworker/u8:1 Not tainted 5.18.0-rc3 #10
[ 1070.278701] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.15.0-0-g2dd4b9b-rebuilt.opensuse.org 04/01/2014
[ 1070.279495] Workqueue: cifs-dfscache refresh_cache_worker [cifs]
[ 1070.280044] RIP: 0010:strcasecmp+0x34/0x150
[ 1070.280359] Code: 00 00 00 fc ff df 41 54 55 48 89 fd 53 48 83 ec 10 eb 03 4c 89 fe 48 89 ef 48 83 c5 01 48 89 f8 48 89 fa 48 c1 e8 03 83 e2 07 <42> 0f b6 04 28 38 d0 7f 08 84 c0 0f 85 bc 00 00 00 0f b6 45 ff 44
[ 1070.281729] RSP: 0018:ffffc90008367958 EFLAGS: 00010246
[ 1070.282114] RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000000
[ 1070.282691] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[ 1070.283273] RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff873eda27
[ 1070.283857] R10: ffffc900083679a0 R11: 0000000000000001 R12: ffff88812624c000
[ 1070.284436] R13: dffffc0000000000 R14: ffff88810e6e9a88 R15: ffff888119bb9000
[ 1070.284990] FS:  0000000000000000(0000) GS:ffff888151200000(0000) knlGS:0000000000000000
[ 1070.285625] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1070.286100] CR2: 0000561a4d922418 CR3: 000000010aecc000 CR4: 0000000000350ee0
[ 1070.286683] Call Trace:
[ 1070.286890]  <TASK>
[ 1070.287070]  refresh_cache_worker+0x895/0xd20 [cifs]
[ 1070.287475]  ? __refresh_tcon.isra.0+0xfb0/0xfb0 [cifs]
[ 1070.287905]  ? __lock_acquire+0xcd1/0x6960
[ 1070.288247]  ? is_dynamic_key+0x1a0/0x1a0
[ 1070.288591]  ? lockdep_hardirqs_on_prepare+0x410/0x410
[ 1070.289012]  ? lock_downgrade+0x6f0/0x6f0
[ 1070.289318]  process_one_work+0x7bd/0x12d0
[ 1070.289637]  ? worker_thread+0x160/0xec0
[ 1070.289970]  ? pwq_dec_nr_in_flight+0x230/0x230
[ 1070.290318]  ? _raw_spin_lock_irq+0x5e/0x90
[ 1070.290619]  worker_thread+0x5ac/0xec0
[ 1070.290891]  ? process_one_work+0x12d0/0x12d0
[ 1070.291199]  kthread+0x2a5/0x350
[ 1070.291430]  ? kthread_complete_and_exit+0x20/0x20
[ 1070.291770]  ret_from_fork+0x22/0x30
[ 1070.292050]  </TASK>
[ 1070.292223] Modules linked in: bpfilter cifs cifs_arc4 cifs_md4
[ 1070.292765] ---[ end trace 0000000000000000 ]---
[ 1070.293108] RIP: 0010:strcasecmp+0x34/0x150
[ 1070.293471] Code: 00 00 00 fc ff df 41 54 55 48 89 fd 53 48 83 ec 10 eb 03 4c 89 fe 48 89 ef 48 83 c5 01 48 89 f8 48 89 fa 48 c1 e8 03 83 e2 07 <42> 0f b6 04 28 38 d0 7f 08 84 c0 0f 85 bc 00 00 00 0f b6 45 ff 44
[ 1070.297718] RSP: 0018:ffffc90008367958 EFLAGS: 00010246
[ 1070.298622] RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000000
[ 1070.299428] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[ 1070.300296] RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff873eda27
[ 1070.301204] R10: ffffc900083679a0 R11: 0000000000000001 R12: ffff88812624c000
[ 1070.301932] R13: dffffc0000000000 R14: ffff88810e6e9a88 R15: ffff888119bb9000
[ 1070.302645] FS:  0000000000000000(0000) GS:ffff888151200000(0000) knlGS:0000000000000000
[ 1070.303462] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1070.304131] CR2: 0000561a4d922418 CR3: 000000010aecc000 CR4: 0000000000350ee0
[ 1070.305004] Kernel panic - not syncing: Fatal exception
[ 1070.305711] Kernel Offset: disabled
[ 1070.305971] ---[ end Kernel panic - not syncing: Fatal exception ]---

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Cc: stable@vger.kernel.org
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-04-20 22:54:17 -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
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
Paulo Alcantara c88f7dcd6d cifs: support nested dfs links over reconnect
Mounting a dfs link that has nested links was already supported at
mount(2), so make it work over reconnect as well.

Make the following case work:

* mount //root/dfs/link /mnt -o ...
  - final share: /server/share

* in server settings
  - change target folder of /root/dfs/link3 to /server/share2
  - change target folder of /root/dfs/link2 to /root/dfs/link3
  - change target folder of /root/dfs/link to /root/dfs/link2

* mount -o remount,... /mnt
 - refresh all dfs referrals
 - mark current connection for failover
 - cifs_reconnect() reconnects to root server
 - tree_connect()
   * checks that /root/dfs/link2 is a link, then chase it
   * checks that root/dfs/link3 is a link, then chase it
   * finally tree connect to /server/share2

If the mounted share is no longer accessible and a reconnect had been
triggered, the client will retry it from both last referral
path (/root/dfs/link3) and original referral path (/root/dfs/link).

Any new referral paths found while chasing dfs links over reconnect,
it will be updated to TCP_Server_Info::leaf_fullpath, accordingly.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-11-10 16:30:13 -06:00
Paulo Alcantara efb21d7b0f cifs: fix print of hdr_flags in dfscache_proc_show()
Reorder the parameters in seq_printf() to correctly print header
flags.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-11-09 20:44:07 -06:00
Paulo Alcantara b62366181a cifs: support share failover when remounting
When remouting a DFS share, force a new DFS referral of the path and
if the currently cached targets do not match any of the new targets or
there was no cached targets, then mark it for reconnect.

For example:

    $ mount //dom/dfs/link /mnt -o username=foo,password=bar
    $ ls /mnt
    oldfile.txt

    change target share of 'link' in server settings

    $ mount /mnt -o remount,username=foo,password=bar
    $ ls /mnt
    newfile.txt

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-07-22 11:43:23 -05:00
Paulo Alcantara 889c2a7007 cifs: fix check of dfs interlinks
Interlink is a special type of DFS link that resolves to a different
DFS domain-based namespace.  To determine whether it is an interlink
or not, check if ReferralServers and StorageServers bits are set to 1
and 0 respectively in ReferralHeaderFlags, as specified in MS-DFSC
3.1.5.4.5 Determining Whether a Referral Response is an Interlink.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-06-20 21:28:17 -05:00
Paulo Alcantara 1023e90b73 cifs: avoid starvation when refreshing dfs cache
When refreshing the DFS cache, keep SMB2 IOCTL calls as much outside
critical sections as possible and avoid read/write starvation when
getting new DFS referrals by using broken or slow connections.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-06-20 21:28:17 -05:00
Paulo Alcantara c950fc7af9 cifs: set a minimum of 2 minutes for refreshing dfs cache
We don't want to refresh the dfs cache in very short intervals, so
setting a minimum interval of 2 minutes is OK.

If it needs to be refreshed immediately, one could have the cache
cleared with

	$ echo 0 > /proc/fs/cifs/dfscache

and then remounting the dfs share.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-06-20 21:28:17 -05:00
Paulo Alcantara 42caeba713 cifs: fix path comparison and hash calc
Fix cache lookup and hash calculations when handling paths with
different cases.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-06-20 21:28:17 -05:00
Paulo Alcantara c870a8e70e cifs: handle different charsets in dfs cache
Convert all dfs paths to dfs cache's local codepage (@cache_cp) and
avoid mixing them with different charsets.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-06-20 21:28:16 -05:00
Paulo Alcantara c9f7110399 cifs: keep referral server sessions alive
At every mount, keep all sessions alive that were used for chasing the
DFS referrals as long as the dfs mounts are active.

Use those sessions in DFS cache to refresh all active tcons as well as
cached entries.  They will be managed by a list of mount_group
structures that will be indexed by a randomly generated uuid at mount
time, so we can put all the sessions related to specific dfs mounts
and avoid leaking them.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-06-20 21:28:16 -05:00
Paulo Alcantara 2b133b7e21 cifs: get rid of @noreq param in __dfs_cache_find()
@noreq param isn't used anywhere, so just remove it.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-06-20 21:28:16 -05:00
YueHaibing a23a71abca cifs: Remove unused inline function is_sysvol_or_netlogon()
is_sysvol_or_netlogon() is never used, so can remove it.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-06-20 21:28:16 -05:00
Al Viro 9cfdb1c12b cifs: constify get_normalized_path() properly
As it is, it takes const char * and, in some cases, stores it in
caller's variable that is plain char *.  Fortunately, none of the
callers actually proceeded to modify the string via now-non-const
alias, but that's trouble waiting to happen.

It's easy to do properly, anyway...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-04-25 16:28:23 -05:00
Al Viro 8d76722355 cifs: don't cargo-cult strndup()
strndup(s, strlen(s)) is a highly unidiomatic way to spell strdup(s);
it's *NOT* safer in any way, since strlen() is just as sensitive to
NUL-termination as strdup() is.

strndup() is for situations when you need a copy of a known-sized
substring, not a magic security juju to drive the bad spirits away.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-04-25 16:28:23 -05:00
Paulo Alcantara 5ff2836ed3 cifs: introduce helper for finding referral server to improve DFS target resolution
Some servers seem to mistakenly report different values for
capabilities and share flags, so we can't always rely on those values
to decide whether the resolved target can handle any new DFS
referrals.

Add a new helper is_referral_server() to check if all resolved targets
can handle new DFS referrals by directly looking at the
GET_DFS_REFERRAL.ReferralHeaderFlags value as specified in MS-DFSC
2.2.4 RESP_GET_DFS_REFERRAL in addition to is_tcon_dfs().

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Cc: stable@vger.kernel.org # 5.11
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-02-25 12:19:15 -06:00
Ronnie Sahlberg 0d4873f9aa cifs: fix dfs domain referrals
The new mount API requires additional changes to how DFS
is handled. Additional testing of DFS uncovered problems
with domain based DFS referrals (a follow on patch addresses
DFS links) which this patch addresses.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-01-28 21:40:43 -06:00
Tom Rix 77b6ec01c2 cifs: check pointer before freeing
clang static analysis reports this problem

dfs_cache.c:591:2: warning: Argument to kfree() is a constant address
  (18446744073709551614), which is not memory allocated by malloc()
        kfree(vi);
        ^~~~~~~~~

In dfs_cache_del_vol() the volume info pointer 'vi' being freed
is the return of a call to find_vol().  The large constant address
is find_vol() returning an error.

Add an error check to dfs_cache_del_vol() similar to the one done
in dfs_cache_update_vol().

Fixes: 54be1f6c1c ("cifs: Add DFS cache routines")
Signed-off-by: Tom Rix <trix@redhat.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
CC: <stable@vger.kernel.org> # v5.0+
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-01-13 12:55:29 -06:00
Ronnie Sahlberg c741cba2cd cifs: move cifs_cleanup_volume_info[_content] to fs_context.c
and rename it to smb3_cleanup_fs_context[_content]

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-14 09:26:30 -06:00
Ronnie Sahlberg 4deb075985 cifs: remove the devname argument to cifs_compose_mount_options
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>
2020-12-13 19:12:07 -06:00
Ronnie Sahlberg 24e0a1eff9 cifs: switch to new mount api
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>
2020-12-13 19:12:07 -06:00
Ronnie Sahlberg 837e3a1bbf cifs: rename dup_vol to smb3_fs_context_dup and move it into fs_context.c
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>
2020-12-13 19:12:07 -06:00
Ronnie Sahlberg 3fa1c6d1b8 cifs: rename smb_vol as smb3_fs_context and move it to fs_context.h
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>
2020-12-13 19:12:07 -06:00
Linus Torvalds 81e11336d9 Merge branch 'akpm' (patches from Andrew)
Merge misc updates from Andrew Morton:

 - a few MM hotfixes

 - kthread, tools, scripts, ntfs and ocfs2

 - some of MM

Subsystems affected by this patch series: kthread, tools, scripts, ntfs,
ocfs2 and mm (hofixes, pagealloc, slab-generic, slab, slub, kcsan,
debug, pagecache, gup, swap, shmem, memcg, pagemap, mremap, mincore,
sparsemem, vmalloc, kasan, pagealloc, hugetlb and vmscan).

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (162 commits)
  mm: vmscan: consistent update to pgrefill
  mm/vmscan.c: fix typo
  khugepaged: khugepaged_test_exit() check mmget_still_valid()
  khugepaged: retract_page_tables() remember to test exit
  khugepaged: collapse_pte_mapped_thp() protect the pmd lock
  khugepaged: collapse_pte_mapped_thp() flush the right range
  mm/hugetlb: fix calculation of adjust_range_if_pmd_sharing_possible
  mm: thp: replace HTTP links with HTTPS ones
  mm/page_alloc: fix memalloc_nocma_{save/restore} APIs
  mm/page_alloc.c: skip setting nodemask when we are in interrupt
  mm/page_alloc: fallbacks at most has 3 elements
  mm/page_alloc: silence a KASAN false positive
  mm/page_alloc.c: remove unnecessary end_bitidx for [set|get]_pfnblock_flags_mask()
  mm/page_alloc.c: simplify pageblock bitmap access
  mm/page_alloc.c: extract the common part in pfn_to_bitidx()
  mm/page_alloc.c: replace the definition of NR_MIGRATETYPE_BITS with PB_migratetype_bits
  mm/shuffle: remove dynamic reconfiguration
  mm/memory_hotplug: document why shuffle_zone() is relevant
  mm/page_alloc: remove nr_free_pagecache_pages()
  mm: remove vm_total_pages
  ...
2020-08-07 11:39:33 -07:00
Waiman Long 453431a549 mm, treewide: rename kzfree() to kfree_sensitive()
As said by Linus:

  A symmetric naming is only helpful if it implies symmetries in use.
  Otherwise it's actively misleading.

  In "kzalloc()", the z is meaningful and an important part of what the
  caller wants.

  In "kzfree()", the z is actively detrimental, because maybe in the
  future we really _might_ want to use that "memfill(0xdeadbeef)" or
  something. The "zero" part of the interface isn't even _relevant_.

The main reason that kzfree() exists is to clear sensitive information
that should not be leaked to other future users of the same memory
objects.

Rename kzfree() to kfree_sensitive() to follow the example of the recently
added kvfree_sensitive() and make the intention of the API more explicit.
In addition, memzero_explicit() is used to clear the memory to make sure
that it won't get optimized away by the compiler.

The renaming is done by using the command sequence:

  git grep -w --name-only kzfree |\
  xargs sed -i 's/kzfree/kfree_sensitive/'

followed by some editing of the kfree_sensitive() kerneldoc and adding
a kzfree backward compatibility macro in slab.h.

[akpm@linux-foundation.org: fs/crypto/inline_crypt.c needs linux/slab.h]
[akpm@linux-foundation.org: fix fs/crypto/inline_crypt.c some more]

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Joe Perches <joe@perches.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: "Jason A . Donenfeld" <Jason@zx2c4.com>
Link: http://lkml.kernel.org/r/20200616154311.12314-3-longman@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07 11:33:22 -07:00
Paulo Alcantara 7548e1da8d cifs: handle RESP_GET_DFS_REFERRAL.PathConsumed in reconnect
Use PathConsumed field when parsing prefixes of referral paths that
either match a cache entry or are a complete prefix path of an
existing entry.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-08-02 18:00:26 -05:00
Paulo Alcantara 2e5de42445 cifs: reduce number of referral requests in DFS link lookups
When looking up the DFS cache with a referral path that has more than
two path components, and is a complete prefix of an existing cache
entry, do not request another referral and just return the matched
entry as specified in MS-DFSC 3.2.5.5 Receiving a Root Referral
Request or Link Referral Request.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-08-02 18:00:26 -05:00
Joe Perches a0a3036b81 cifs: Standardize logging output
Use pr_fmt to standardize all logging for fs/cifs.

Some logging output had no CIFS: specific prefix.

Now all output has one of three prefixes:

o CIFS:
o CIFS: VFS:
o Root-CIFS:

Miscellanea:

o Convert printks to pr_<level>
o Neaten macro definitions
o Remove embedded CIFS: prefixes from formats
o Convert "illegal" to "invalid"
o Coalesce formats
o Add missing '\n' format terminations
o Consolidate multiple cifs_dbg continuations into single calls
o More consistent use of upper case first word output logging
o Multiline statement argument alignment and wrapping

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-06-01 00:10:18 -05:00
Paulo Alcantara (SUSE) bacd704a95 cifs: handle prefix paths in reconnect
For the case where we have a DFS path like below and we're currently
connected to targetA:

    //dfsroot/link -> //targetA/share/foo, //targetB/share/bar

after failover, we should make sure to update cifs_sb->prepath so the
next operations will use the new prefix path "/bar".

Besides, in order to simplify the use of different prefix paths,
enforce CIFS_MOUNT_USE_PREFIX_PATH for DFS mounts so we don't have to
revalidate the root dentry every time we set a new prefix path.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-03-22 22:49:09 -05:00
Alexey Dobriyan 97a32539b9 proc: convert everything to "struct proc_ops"
The most notable change is DEFINE_SHOW_ATTRIBUTE macro split in
seq_file.h.

Conversion rule is:

	llseek		=> proc_lseek
	unlocked_ioctl	=> proc_ioctl

	xxx		=> proc_xxx

	delete ".owner = THIS_MODULE" line

[akpm@linux-foundation.org: fix drivers/isdn/capi/kcapi_proc.c]
[sfr@canb.auug.org.au: fix kernel/sched/psi.c]
  Link: http://lkml.kernel.org/r/20200122180545.36222f50@canb.auug.org.au
Link: http://lkml.kernel.org/r/20191225172546.GB13378@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-02-04 03:05:26 +00:00
Chen Zhou 050d2a8b69 cifs: use PTR_ERR_OR_ZERO() to simplify code
PTR_ERR_OR_ZERO contains if(IS_ERR(...)) + PTR_ERR, just use
PTR_ERR_OR_ZERO directly.

Signed-off-by: Chen Zhou <chenzhou10@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
2020-01-26 19:24:17 -06:00
Steve French 463a7b457c cifs: fix unitialized variable poential problem with network I/O cache lock patch
static analysis with Coverity detected an issue with the following
commit:

 Author: Paulo Alcantara (SUSE) <pc@cjr.nz>
 Date:   Wed Dec 4 17:38:03 2019 -0300

    cifs: Avoid doing network I/O while holding cache lock

Addresses-Coverity: ("Uninitialized pointer read")
Reported-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-01-26 19:24:16 -06:00
YueHaibing eecfc57130 cifs: Fix return value in __update_cache_entry
copy_ref_data() may return error, it should be
returned to upstream caller.

Fixes: 03535b72873b ("cifs: Avoid doing network I/O while holding cache lock")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-01-26 19:24:16 -06:00
Paulo Alcantara (SUSE) 742d8de018 cifs: Avoid doing network I/O while holding cache lock
When creating or updating a cache entry, we need to get an DFS
referral (get_dfs_referral), so avoid holding any locks during such
network operation.

To prevent that, do the following:
* change cache hashtable sync method from RCU sync to a read/write
  lock.
* use GFP_ATOMIC in memory allocations.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-01-26 19:24:16 -06:00
Paulo Alcantara (SUSE) 06d57378bc cifs: Fix potential deadlock when updating vol in cifs_reconnect()
We can't acquire volume lock while refreshing the DFS cache because
cifs_reconnect() may call dfs_cache_update_vol() while we are walking
through the volume list.

To prevent that, make vol_info refcounted, create a temp list with all
volumes eligible for refreshing, and then use it without any locks
held.

Besides, replace vol_lock with a spinlock and protect cache_ttl from
concurrent accesses or changes.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-01-26 19:24:16 -06:00
Paulo Alcantara (SUSE) ff2f7fc082 cifs: Merge is_path_valid() into get_normalized_path()
Just do the trivial path validation in get_normalized_path().

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-01-26 19:24:16 -06:00
Paulo Alcantara (SUSE) 345c1a4a9e cifs: Introduce helpers for finding TCP connection
Add helpers for finding TCP connections that are good candidates for
being used by DFS refresh worker.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-01-26 19:24:16 -06:00
Paulo Alcantara (SUSE) 199c6bdfb0 cifs: Get rid of kstrdup_const()'d paths
The DFS cache API is mostly used with heap allocated strings.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-01-26 19:24:16 -06:00
Paulo Alcantara (SUSE) 185352ae61 cifs: Clean up DFS referral cache
Do some renaming and code cleanup.

No functional changes.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-01-26 19:24:16 -06:00
Paulo Alcantara (SUSE) df3df923b3 cifs: Fix lookup of root ses in DFS referral cache
We don't care about module aliasing validation in
cifs_compose_mount_options(..., is_smb3) when finding the root SMB
session of an DFS namespace in order to refresh DFS referral cache.

The following issue has been observed when mounting with '-t smb3' and
then specifying 'vers=2.0':

...
Nov 08 15:27:08 tw kernel: address conversion returned 0 for FS0.WIN.LOCAL
Nov 08 15:27:08 tw kernel: [kworke] ==> dns_query((null),FS0.WIN.LOCAL,13,(null))
Nov 08 15:27:08 tw kernel: [kworke] call request_key(,FS0.WIN.LOCAL,)
Nov 08 15:27:08 tw kernel: [kworke] ==> dns_resolver_cmp(FS0.WIN.LOCAL,FS0.WIN.LOCAL)
Nov 08 15:27:08 tw kernel: [kworke] <== dns_resolver_cmp() = 1
Nov 08 15:27:08 tw kernel: [kworke] <== dns_query() = 13
Nov 08 15:27:08 tw kernel: fs/cifs/dns_resolve.c: dns_resolve_server_name_to_ip: resolved: FS0.WIN.LOCAL to 192.168.30.26
===> Nov 08 15:27:08 tw kernel: CIFS VFS: vers=2.0 not permitted when mounting with smb3
Nov 08 15:27:08 tw kernel: fs/cifs/dfs_cache.c: CIFS VFS: leaving refresh_tcon (xid = 26) rc = -22
...

Fixes: 5072010ccf ("cifs: Fix DFS cache refresher for DFS links")
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-11-25 09:25:32 -06:00
Kefeng Wang 06f2fca7ff fs: cifs: Drop unlikely before IS_ERR(_OR_NULL)
IS_ERR(_OR_NULL) already contain an 'unlikely' compiler flag,
so no need to do that again from its callers. Drop it.

Cc: linux-cifs@vger.kernel.org
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Paulo Alcantara <palcantara@suse.de>
2019-07-07 22:37:42 -05:00
Gen Zhang 50fbc13dc1 dfs_cache: fix a wrong use of kfree in flush_cache_ent()
In flush_cache_ent(), 'ce->ce_path' is allocated by kstrdup_const().
It should be freed by kfree_const(), rather than kfree().

Signed-off-by: Gen Zhang <blackgod016574@gmail.com>
Reviewed-by: Paulo Alcantara <palcantara@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-05-28 19:13:58 -05:00