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>
With commit 506c1da44f ("cifs: use the expiry output of dns_query to
schedule next resolution") and after triggering the first reconnect,
the next async dns resolution of tcp server's hostname would be
scheduled based on dns_resolver's key expiry default, which happens to
default to 5s on most systems that use key.dns_resolver for upcall.
As per key.dns_resolver.conf(5):
default_ttl=<number>
The number of seconds to set as the expiration on a cached
record. This will be overridden if the program manages to re-
trieve TTL information along with the addresses (if, for exam-
ple, it accesses the DNS directly). The default is 5 seconds.
The value must be in the range 1 to INT_MAX.
Make the next async dns resolution no shorter than 120s as we do not
want to be upcalling too often.
Cc: stable@vger.kernel.org
Fixes: 506c1da44f ("cifs: use the expiry output of dns_query to schedule next resolution")
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>
Make two separate functions that handle dfs and non-dfs reconnect
logics since cifs_reconnect() became way too complex to handle both.
While at it, add some documentation.
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>
Convert list_for_each{,_safe} to list_for_each_entry{,_safe} in
cifs_mark_tcp_ses_conns_for_reconnect() function.
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>
Create cifs_mark_tcp_ses_conns_for_reconnect() helper to mark all
sessions and tcons for reconnect when reconnecting tcp server.
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>
During the ntlmssp session setup (authenticate phases)
send the client workstation info. This can make debugging easier on
servers.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
Today, when a new mount is done with nosharesock, we ensure
that we don't select an existing matching session. However,
we don't mark the connection as nosharesock, which means that
those could be shared with future sessions.
Fixed it with this commit. Also printing this info in DebugData.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
This file will contain all the definitions we need for SMB2 packets
and will follow the naming convention of MS-SMB2.PDF as closely
as possible to make it easier to cross-reference beween the definitions
and the standard.
The content of this file will mostly consist of migration of existing
definitions in the cifs/smb2.pdu.h and ksmbd/smb2pdu.h files
with some additional tweaks as the two files have diverged.
This patch introduces the new smbfs_common/smb2pdu.h file
and migrates the SMB2 header as well as TREE_CONNECT and TREE_DISCONNECT
to the shared file.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
We generally rely on a bunch of factors to differentiate between servers.
For example, IP address, port etc.
For certain server types (like Azure), it is important to make sure
that the server hostname matches too, even if the both hostnames currently
resolve to the same IP address.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Cc: stable@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Although very unlikely that the tlink pointer would be null in this case,
get_next_mid function can in theory return null (but not an error)
so need to check for null (not for IS_ERR, which can not be returned
here).
Address warning:
fs/smbfs_client/connect.c:2392 cifs_match_super()
warn: 'tlink' isn't an ERR_PTR
Pointed out by Dan Carpenter via smatch code analysis tool
CC: stable@vger.kernel.org
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Correct kernel-doc comments pointed out by the
automated kernel test robot.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
checkpatch complains about source files with filenames (e.g. in
these cases just below the SPDX header in comments at the top of
various files in fs/cifs). It also is helpful to change this now
so will be less confusing when the parent directory is renamed
e.g. from fs/cifs to fs/smb_client (or fs/smbfs)
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
for SMB1.
This removes the dependency to DES.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
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>
Make sure that we do not share tcp sessions of dfs mounts when
mounting regular shares that connect to same server. DFS connections
rely on a single instance of tcp in order to do failover properly in
cifs_reconnect().
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
We have a few ref counters srv_count, ses_count and
tc_count which we use for ref counting. Added a WARN_ON
during the decrement of each of these counters to make
sure that they don't go below their minimum values.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Although it is unlikely to be have ended up with a null
session pointer calling cifs_try_adding_channels in cifs_mount.
Coverity correctly notes that we are already checking for
it earlier (when we return from do_dfs_failover), so at
a minimum to clarify the code we should make sure we also
check for it when we exit the loop so we don't end up calling
cifs_try_adding_channels or mount_setup_tlink with a null
ses pointer.
Addresses-Coverity: 1505608 ("Derefernce after null check")
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
When there is no cached DFS referral of tcon->dfs_path, then reconnect
to same share.
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
We recently fixed DNS resolution of the server hostname during reconnect.
However, server IP address may change, even when the old one continues
to server (although sub-optimally).
We should schedule the next DNS resolution based on the TTL of
the DNS record used for the last resolution. This way, we resolve the
server hostname again when a DNS record expires.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Cc: <stable@vger.kernel.org> # v5.11+
Signed-off-by: Steve French <stfrench@microsoft.com>
There were three places where we were not taking the spinlock
around updates to server->tcpStatus when it was being modified.
To be consistent (also removes Coverity warning) and to remove
possibility of race best to lock all places where it is updated.
Two of the three were in initialization of the field and can't
race - but added lock around the other.
Addresses-Coverity: 1399512 ("Data race condition")
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
In the other places where we update ses->status we protect the
updates via GlobalMid_Lock. So to be consistent add the same
locking around it in cifs_put_smb_ses where it was missing.
Addresses-Coverity: 1268904 ("Data race condition")
Signed-off-by: Steve French <stfrench@microsoft.com>
We weren't checking if tcon is null before setting dfs path,
although we check for null tcon in an earlier assignment statement.
Addresses-Coverity: 1476411 ("Dereference after null check")
Signed-off-by: Steve French <stfrench@microsoft.com>
Add SPDX license identifier and replace license boilerplate.
Corrects various checkpatch errors with the older format for
noting the LGPL license.
Signed-off-by: Steve French <stfrench@microsoft.com>
It isn't enough to have unshared tcons because multiple DFS mounts can
connect to same target server and failover to different servers, so we
can't use a single tcp server for such cases.
For the simplest solution, use nosharesock option to achieve that.
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
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>
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>
On session close, the IPC is closed and the server must release all
tcons of the session. It doesn't matter if we send a ipc close or
not.
Besides, it will make the server to not close durable and resilient
files on session close, as specified in MS-SMB2 3.3.5.6 Receiving an
SMB2 LOGOFF 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>
The commit 315db9a05b ("cifs: fix leak in cifs_smb3_do_mount() ctx")
revealed an existing bug when mounting shares that contain a prefix
path or DFS links.
cifs_setup_volume_info() requires the @devname to contain the full
path (UNC + prefix) to update the fs context with the new UNC and
prepath values, however we were passing only the UNC
path (old_ctx->UNC) in @device thus discarding any prefix paths.
Instead of concatenating both old_ctx->{UNC,prepath} and pass it in
@devname, just keep the dup'ed values of UNC and prepath in
cifs_sb->ctx after calling smb3_fs_context_dup(), and fix
smb3_parse_devname() to correctly parse and not leak the new UNC and
prefix paths.
Cc: <stable@vger.kernel.org> # v5.11+
Fixes: 315db9a05b ("cifs: fix leak in cifs_smb3_do_mount() ctx")
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Acked-by: David Disseldorp <ddiss@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
When the tcp connection is not ready to send requests,
we keep retrying echo with an interval of zero.
This seems unnecessary, and this fix changes the interval
between echoes to what is specified as echo_interval.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
We can detect server unresponsiveness only if echoes are enabled.
Echoes can be disabled under two scenarios:
1. The connection is low on credits, so we've disabled echoes/oplocks.
2. The connection has not seen any request till now (other than
negotiate/sess-setup), which is when we enable these two, based on
the credits available.
So this fix will check for dead connection, only when echo is enabled.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
CC: <stable@vger.kernel.org> # v5.8+
Signed-off-by: Steve French <stfrench@microsoft.com>
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>
This commit doesn't change the logic of SWN.
Add dummy implementation of SWN functions when SWN is disabled instead
of using ifdef sections.
The dummy functions get optimized out, this leads to clearer code and
compile time type-checking regardless of config options with no
runtime penalty.
Leave the simple ifdefs section as-is.
A single bitfield (bool foo:1) on its own will use up one int. Move
tcon->use_witness out of ifdefs with the other tcon bitfields.
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Samuel Cabrero <scabrero@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
On cifs_reconnect, make sure that DNS resolution happens again.
It could be the cause of connection to go dead in the first place.
This also contains the fix for a build issue identified by Intel bot.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
CC: <stable@vger.kernel.org> # 5.11+
Signed-off-by: Steve French <stfrench@microsoft.com>
The MIDs are mostly printed as decimal, so let's make it consistent.
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
With multichannel, operations like the queries
from "ls -lR" can cause all credits to be used and
errors to be returned since max_credits was not
being set correctly on the secondary channels and
thus the client was requesting 0 credits incorrectly
in some cases (which can lead to not having
enough credits to perform any operation on that
channel).
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
CC: <stable@vger.kernel.org> # v5.8+
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
The iterator, ITER_DISCARD, that can only be used in READ mode and
just discards any data copied to it, was added to allow a network
filesystem to discard any unwanted data sent by a server.
Convert cifs_discard_from_socket() to use this.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
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>
Handle the case where a resolved target share is like
//server/users/dir, and the user "foo" has no read permission to
access the parent folder "users" but has access to the final path
component "dir".
is_path_remote() already implements that, so call it directly.
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Cc: stable@vger.kernel.org # 5.11
Signed-off-by: Steve French <stfrench@microsoft.com>
In do_dfs_failover(), the mount_get_conns() function requires the full
fs context in order to get new connection to server, so clone the
original context and change it accordingly when retrying the DFS
targets in the referral.
If failover was successful, then update original context with the new
UNC, prefix path and ip address.
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Cc: stable@vger.kernel.org # 5.11
Signed-off-by: Steve French <stfrench@microsoft.com>
Skip DFS resolving when mounting with 'nodfs' even if
CONFIG_CIFS_DFS_UPCALL is enabled.
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Cc: stable@vger.kernel.org # 5.11
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
The new optional mount parameter "acregmax" allows a different
timeout for file metadata ("acdirmax" now allows controlling timeout
for directory metadata). Setting "actimeo" still works as before,
and changes timeout for both files and directories, but
specifying "acregmax" or "acdirmax" allows overriding the
default more granularly which can be a big performance benefit
on some workloads. "acregmax" is already used by NFS as a mount
parameter (albeit with a larger default and thus looser caching).
Suggested-by: Tom Talpey <tom@talpey.com>
Reviewed-By: Tom Talpey <tom@talpey.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
nfs and cifs on Linux currently have a mount parameter "actimeo" to control
metadata (attribute) caching but cifs does not have additional mount
parameters to allow distinguishing between caching directory metadata
(e.g. needed to revalidate paths) and that for files.
Add new mount parameter "acdirmax" to allow caching metadata for
directories more loosely than file data. NFS adjusts metadata
caching from acdirmin to acdirmax (and another two mount parms
for files) but to reduce complexity, it is safer to just introduce
the one mount parm to allow caching directories longer. The
defaults for acdirmax and actimeo (for cifs.ko) are conservative,
1 second (NFS defaults acdirmax to 60 seconds). For many workloads,
setting acdirmax to a higher value is safe and will improve
performance. This patch leaves unchanged the default values
for caching metadata for files and directories but gives the
user more flexibility in adjusting them safely for their workload
via the new mount parm.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-By: Tom Talpey <tom@talpey.com>
When server returns error STATUS_NETWORK_NAME_DELETED, TCON
must be marked for reconnect. So, subsequent IO does the tree
connect again.
Signed-off-by: Rohith Surabattula <rohiths@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
ses->serverName is not the server name, but the string form
of the ip address of the server. Change the name to ip_addr
to avoid confusion (and fix the array length to match
maximum length of ipv6 address).
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Introduced a new field conn_id in TCP_Server_Info structure.
This is a non-persistent unique identifier maintained by the client
for a connection to a file server. For this, a global counter named
tcpSesNextId is maintained. On allocating a new TCP_Server_Info,
this counter is incremented and assigned.
Changed the dynamic tracepoints related to reconnects and
crediting to be more informative (with conn_id printed).
Debugging a crediting issue helped me understand the
important things to print here.
Always call dynamic tracepoints outside the scope of spinlocks.
To do this, copy out the credits and in_flight fields of the
server struct before dropping the lock.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
While debugging another issue today, Steve and I noticed that if a
subdir for a file share is already mounted on the client, any new
mount of any other subdir (or the file share root) of the same share
results in sharing the cifs superblock, which e.g. can result in
incorrect device name.
While setting prefix path for the root of a cifs_sb,
CIFS_MOUNT_USE_PREFIX_PATH flag should also be set.
Without it, prepath is not even considered in some places,
and output of "mount" and various /proc/<>/*mount* related
options can be missing part of the device name.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
This fixes a regression following dfs links that was introduced in the
patch series for the new mount api.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
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>
