Commit Graph

790 Commits

Author SHA1 Message Date
Jiapeng Zhong 16a78851e1 fs/cifs: Simplify bool comparison.
Fix the follow warnings:

./fs/cifs/connect.c: WARNING: Comparison of 0/1 to bool variable

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Zhong <abaci-bugfix@linux.alibaba.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-01-17 19:22:24 -06:00
Jiapeng Zhong 2be449fcf3 fs/cifs: Assign boolean values to a bool variable
Fix the following coccicheck warnings:

./fs/cifs/connect.c:3386:2-21: WARNING: Assignment of 0/1 to
bool variable.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Zhong <abaci-bugfix@linux.alibaba.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-01-17 19:22:18 -06:00
YANG LI ed6b1920f8 cifs: connect: style: Simplify bool comparison
Fix the following coccicheck warning:
./fs/cifs/connect.c:3740:6-21: WARNING: Comparison of 0/1 to bool
variable

Signed-off-by: YANG LI <abaci-bugfix@linux.alibaba.com>
Reported-by: Abaci Robot<abaci@linux.alibaba.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-01-13 12:55:40 -06:00
Samuel Cabrero 0bf1bafb17 cifs: Avoid error pointer dereference
The patch 7d6535b72042: "cifs: Simplify reconnect code when dfs
upcall is enabled" leads to the following static checker warning:

	fs/cifs/connect.c:160 reconn_set_next_dfs_target()
	error: 'server->hostname' dereferencing possible ERR_PTR()

Avoid dereferencing the error pointer by early returning on error
condition.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Samuel Cabrero <scabrero@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-18 07:40:21 -06:00
Shyam Prasad N cd7b699b01 cifs: Tracepoints and logs for tracing credit changes.
There is at least one suspected bug in crediting changes in cifs.ko
which has come up a few times in the discussions and in a customer
case.

This change adds tracepoints to the code which modifies the server
credit values in any way. The goal is to be able to track the changes
to the credit values of the session to be able to catch when there is
a crediting bug.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-15 16:56:04 -06:00
Steve French 0c2b5f7ce5 cifs: fix rsize/wsize to be negotiated values
Also make sure these are displayed in /proc/mounts

Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
2020-12-15 15:13:59 -06:00
Ronnie Sahlberg 2d39f50c2b cifs: move update of flags into a separate function
This function will set/clear flags that can be changed during mount or remount

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-14 09:28:25 -06:00
Ronnie Sahlberg 51acd208bd cifs: remove ctx argument from cifs_setup_cifs_sb
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 6fd4ea88b5 cifs: don't create a temp nls in cifs_setup_ipc
just use the one that is already available in ctx

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 387ec58f33 cifs: simplify handling of cifs_sb/ctx->local_nls
Only load/unload local_nls from cifs_sb and just make the ctx
contain a pointer to cifs_sb->ctx.

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 522aa3b575 cifs: move [brw]size from cifs_sb to cifs_sb->ctx
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 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
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
Ronnie Sahlberg af1e40d9ac cifs: remove actimeo from cifs_sb
Can now be accessed via the ctx

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-14 09:16:23 -06:00
Ronnie Sahlberg 8401e93678 cifs: remove [gu]id/backup[gu]id/file_mode/dir_mode from cifs_sb
We can already access these from cifs_sb->ctx so we no longer need
a local copy in cifs_sb.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-14 09:16:23 -06:00
Samuel Cabrero 7d6535b720 cifs: Simplify reconnect code when dfs upcall is enabled
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>
2020-12-14 09:16:23 -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 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
Samuel Cabrero 0ac4e2919a cifs: add witness mount option and data structs
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>
2020-12-14 09:16:22 -06:00
Steve French bc04499477 cifs: minor kernel style fixes for comments
Trivial fix for a few comments which didn't follow kernel style

Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-14 09:16:22 -06:00
Samuel Cabrero a87e67254b cifs: Make extract_hostname function public
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>
2020-12-14 09:16:22 -06:00
Ronnie Sahlberg a2a52a8a36 cifs: get rid of cifs_sb->mountdata
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>
2020-12-13 19:12:07 -06:00
Ronnie Sahlberg d17abdf756 cifs: add an smb3_fs_context to cifs_sb
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>
2020-12-13 19:12:07 -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 66e7b09c73 cifs: move cifs_parse_devname to fs_context.c
Also rename the function from cifs_ to smb3_

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 15c7d09af2 cifs: move the enum for cifs parameters into fs_context.h
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>
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
Aurelien Aptel 59463eb888 cifs: add NULL check for ses->tcon_ipc
In some scenarios (DFS and BAD_NETWORK_NAME) set_root_set() can be
called with a NULL ses->tcon_ipc.

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-03 17:06:03 -06:00
Paulo Alcantara 212253367d cifs: fix potential use-after-free in cifs_echo_request()
This patch fixes a potential use-after-free bug in
cifs_echo_request().

For instance,

  thread 1
  --------
  cifs_demultiplex_thread()
    clean_demultiplex_info()
      kfree(server)

  thread 2 (workqueue)
  --------
  apic_timer_interrupt()
    smp_apic_timer_interrupt()
      irq_exit()
        __do_softirq()
          run_timer_softirq()
            call_timer_fn()
	      cifs_echo_request() <- use-after-free in server ptr

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-11-30 15:23:45 -06:00
Ronnie Sahlberg 555782aa55 cifs: move smb version mount options into fs_context.c
This and related patches which move mount related
code to fs_context.c has the advantage of
shriking the code in fs/cifs/connect.c (which had
the second most lines of code of any of the files
in cifs.ko and was getting harder to read due
to its size) and will also make it easier to
switch over to the new mount API in the future.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-10-22 12:17:31 -05:00
Ronnie Sahlberg 2f20f07686 cifs: move cache mount options to fs_context.ch
Helps to shrink connect.c and make it more readable
by moving mount related code to fs_context.c and
fs_context.h

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
2020-10-22 12:17:05 -05:00
Ronnie Sahlberg 5c6e5aa496 cifs: move security mount options into fs_context.ch
This patch moves the parsing of security mount options into
fs_context.ch.  There are no changes to any logic.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
2020-10-22 12:16:44 -05:00
Steve French 3c6e65e679 smb3: do not try to cache root directory if dir leases not supported
To servers which do not support directory leases (e.g. Samba)
it is wasteful to try to open_shroot (ie attempt to cache the
root directory handle).  Skip attempt to open_shroot when
server does not indicate support for directory leases.

Cuts the number of requests on mount from 17 to 15, and
cuts the number of requests on stat of the root directory
from 4 to 3.

Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org> # v5.1+
2020-10-21 17:57:07 -05:00
Samuel Cabrero def6e1dc17 cifs: Print the address and port we are connecting to in generic_ip_connect()
Can be helpful in debugging mount and reconnect issues

Signed-off-by: Samuel Cabrero <scabrero@suse.de>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-10-21 17:57:02 -05:00
Rohith Surabattula 8e670f77c4 Handle STATUS_IO_TIMEOUT gracefully
Currently STATUS_IO_TIMEOUT is not treated as retriable error.
It is currently mapped to ETIMEDOUT and returned to userspace
for most system calls. STATUS_IO_TIMEOUT is returned by server
in case of unavailability or throttling errors.

This patch will map the STATUS_IO_TIMEOUT to EAGAIN, so that it
can be retried. Also, added a check to drop the connection to
not overload the server in case of ongoing unavailability.

Signed-off-by: Rohith Surabattula <rohiths@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-10-15 23:58:04 -05:00
Linus Torvalds 3edd8db2d5 DFS SMB1 Fix
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Merge tag '5.9-rc2-smb-fix' of git://git.samba.org/sfrench/cifs-2.6

Pull cfis fix from Steve French:
 "DFS fix for referral problem when using SMB1"

* tag '5.9-rc2-smb-fix' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: fix check of tcon dfs in smb1
2020-08-30 11:38:21 -07:00
Paulo Alcantara e183785f25 cifs: fix check of tcon dfs in smb1
For SMB1, the DFS flag should be checked against tcon->Flags rather
than tcon->share_flags.  While at it, add an is_tcon_dfs() helper to
check for DFS capability in a more generic way.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Shyam Prasad N <nspmangalore@gmail.com>
2020-08-28 12:27:33 -05:00
Gustavo A. R. Silva df561f6688 treewide: Use fallthrough pseudo-keyword
Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-23 17:36:59 -05:00
Linus Torvalds f6513bd39c 3 small cifs/smb3 fixes, one for stable fixing mkdir path with idsfromsid mount option
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Merge tag '5.9-rc-smb3-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs fixes from Steve French:
 "Three small cifs/smb3 fixes, one for stable fixing mkdir path with
  the 'idsfromsid' mount option"

* tag '5.9-rc-smb3-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6:
  SMB3: Fix mkdir when idsfromsid configured on mount
  cifs: Convert to use the fallthrough macro
  cifs: Fix an error pointer dereference in cifs_mount()
2020-08-15 08:31:39 -07:00
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
Dan Carpenter 20b135e48c cifs: Fix an error pointer dereference in cifs_mount()
The error handling calls kfree(full_path) so we can't let it be a NULL
pointer.  There used to be a NULL assignment here but we accidentally
deleted it.  Add it back.

Fixes: 7efd081582 ("cifs: document and cleanup dfs mount")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
2020-08-06 22:06:10 -05:00
Paulo Alcantara 7efd081582 cifs: document and cleanup dfs mount
cifs_mount() for DFS mounts is for a long time way too complex to
follow, mostly because it lacks some documentation, does a lot of
operations like resolving DFS roots and links, checking for path
components, perform failover, crap code, etc.

Besides adding some documentation to it, do some cleanup and ensure
that the following is implemented and supported:

    * non-DFS mounts
    * DFS failover
    * DFS root mounts
        - tcon and cifs_sb must contain DFS path (NOT including prefix)
        - if prefix path, then save it in cifs_sb and it must not be
	  changed
    * DFS link mounts
      - tcon and cifs_sb must contain DFS path (including prefix)
      - if prefix path, then save it in cifs_sb and it may be changed
    * prevent recursion on broken link referrals (MAX_NESTED_LINKS)
    * check every path component of the currently resolved
      target (including prefix), and chase them accordingly
    * make sure that DFS referrals go through newly resolved root
      servers

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 11375a59a9 cifs: only update prefix path of DFS links in cifs_tree_connect()
For DFS root mounts that contain a prefix path, do not change them
after failover.

E.g., if the user mounts

	//srvA/root/dir1

and then lost connection to srvA, it will reconnect to

	//srvB/root/dir1

In case of DFS links, which may resolve to different prefix paths
depending on their list of targets, the following must be supported:

	- mount //srvA/root/link/bar
	- connect to //srvA/share
	- set prefix path to "bar"
	- lost connection to srvA
	- reconnect to next target: //srvB/share/foo
	- set new prefix path to "foo/bar"

In cifs_tree_connect(), check the server_type field of the cached DFS
referral to determine whether or not prefix path should be updated.

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
Colin Ian King c6a80e1ff4 cifs: fix double free error on share and prefix
Currently if the call dfs_cache_get_tgt_share fails we cannot
fully guarantee that share and prefix are set to NULL and the
next iteration of the loop can end up potentially double freeing
these pointers. Since the semantics of dfs_cache_get_tgt_share
are ambiguous for failure cases with the setting of share and
prefix (currently now and the possibly the future), it seems
prudent to set the pointers to NULL when the objects are
free'd to avoid any double frees.

Addresses-Coverity: ("Double free")
Fixes: 96296c946a2a ("cifs: handle RESP_GET_DFS_REFERRAL.PathConsumed in reconnect")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
2020-08-02 18:00:26 -05:00
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 a52930353e cifs: handle empty list of targets in cifs_reconnect()
In case there were no cached DFS referrals in
reconn_setup_dfs_targets(), set cifs_sb to NULL prior to calling
reconn_set_next_dfs_target() so it would not try to access an empty
tgt_list.

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 7d397a034d cifs: rename reconn_inval_dfs_target()
This function has nothing to do with *invalidation* but setting up the
next target server from a cached referral.

Rename it to reconn_set_next_dfs_target().  While at it, get rid of
some meaningless checks.

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
Stefan Metzmacher 565674d613 cifs: merge __{cifs,smb2}_reconnect[_tcon]() into cifs_tree_connect()
They were identical execpt to CIFSTCon() vs. SMB2_tcon().
These are also available via ops->tree_connect().

Signed-off-by: Stefan Metzmacher <metze@samba.org>
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