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path: root/fs/cifs/transport.c
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2023-03-22cifs: Move the in_send statistic to __smb_send_rqst()Zhang Xiaoxu
[ Upstream commit d0dc41119905f740e8d5594adce277f7c0de8c92 ] When send SMB_COM_NT_CANCEL and RFC1002_SESSION_REQUEST, the in_send statistic was lost. Let's move the in_send statistic to the send function to avoid this scenario. Fixes: 7ee1af765dfa ("[CIFS]") Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-09-28cifs: always initialize struct msghdr smb_msg completelyStefan Metzmacher
[ Upstream commit bedc8f76b3539ac4f952114b316bcc2251e808ce ] So far we were just lucky because the uninitialized members of struct msghdr are not used by default on a SOCK_STREAM tcp socket. But as new things like msg_ubuf and sg_from_iter where added recently, we should play on the safe side and avoid potention problems in future. Signed-off-by: Stefan Metzmacher <metze@samba.org> Cc: stable@vger.kernel.org Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-09-28cifs: don't send down the destination address to sendmsg for a SOCK_STREAMStefan Metzmacher
commit 17d3df38dc5f4cec9b0ac6eb79c1859b6e2693a4 upstream. This is ignored anyway by the tcp layer. Signed-off-by: Stefan Metzmacher <metze@samba.org> Cc: stable@vger.kernel.org Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com> Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-30cifs: change noisy error message to FYIPaulo Alcantara
[ Upstream commit e3d100eae44b42f309c1366efb8397368f1cf8ed ] A customer has reported that their dmesg were being flooded by CIFS: VFS: \\server Cancelling wait for mid xxx cmd: a CIFS: VFS: \\server Cancelling wait for mid yyy cmd: b CIFS: VFS: \\server Cancelling wait for mid zzz cmd: c because some processes that were performing statfs(2) on the share had been interrupted due to their automount setup when certain users logged in and out. Change it to FYI as they should be mostly informative rather than error messages. 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> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-24cifs: Fix preauth hash corruptionVincent Whitchurch
commit 05946d4b7a7349ae58bfa2d51ae832e64a394c2d upstream. smb311_update_preauth_hash() uses the shash in server->secmech without appropriate locking, and this can lead to sessions corrupting each other's preauth hashes. The following script can easily trigger the problem: #!/bin/sh -e NMOUNTS=10 for i in $(seq $NMOUNTS); mkdir -p /tmp/mnt$i umount /tmp/mnt$i 2>/dev/null || : done while :; do for i in $(seq $NMOUNTS); do mount -t cifs //192.168.0.1/test /tmp/mnt$i -o ... & done wait for i in $(seq $NMOUNTS); do umount /tmp/mnt$i done done Usually within seconds this leads to one or more of the mounts failing with the following errors, and a "Bad SMB2 signature for message" is seen in the server logs: CIFS: VFS: \\192.168.0.1 failed to connect to IPC (rc=-13) CIFS: VFS: cifs_mount failed w/return code = -13 Fix it by holding the server mutex just like in the other places where the shashes are used. Fixes: 8bd68c6e47abff34e4 ("CIFS: implement v3.11 preauth integrity") Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com> CC: <stable@vger.kernel.org> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com> [aaptel: backport to kernel without CIFS_SESS_OP] Signed-off-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-10smb3: fix crediting for compounding when only one request in flightPavel Shilovsky
commit 91792bb8089b63b7b780251eb83939348ac58a64 upstream. Currently we try to guess if a compound request is going to succeed waiting for credits or not based on the number of requests in flight. This approach doesn't work correctly all the time because there may be only one request in flight which is going to bring multiple credits satisfying the compound request. Change the behavior to fail a request only if there are no requests in flight at all and proceed waiting for credits otherwise. Cc: <stable@vger.kernel.org> # 5.1+ Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> Reviewed-by: Tom Talpey <tom@talpey.com> Reviewed-by: Shyam Prasad N <nspmangalore@gmail.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-27cifs: do not fail __smb_send_rqst if non-fatal signals are pendingRonnie Sahlberg
commit 214a5ea081e77346e4963dd6d20c5539ff8b6ae6 upstream. RHBZ 1848178 The original intent of returning an error in this function in the patch: "CIFS: Mask off signals when sending SMB packets" was to avoid interrupting packet send in the middle of sending the data (and thus breaking an SMB connection), but we also don't want to fail the request for non-fatal signals even before we have had a chance to try to send it (the reported problem could be reproduced e.g. by exiting a child process when the parent process was in the midst of calling futimens to update a file's timestamps). In addition, since the signal may remain pending when we enter the sending loop, we may end up not sending the whole packet before TCP buffers become full. In this case the code returns -EINTR but what we need here is to return -ERESTARTSYS instead to allow system calls to be restarted. Fixes: b30c74c73c78 ("CIFS: Mask off signals when sending SMB packets") Cc: stable@vger.kernel.org # v5.1+ Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-11cifs: allow syscalls to be restarted in __smb_send_rqst()Paulo Alcantara
commit 6988a619f5b79e4efadea6e19dcfe75fbcd350b5 upstream. A customer has reported that several files in their multi-threaded app were left with size of 0 because most of the read(2) calls returned -EINTR and they assumed no bytes were read. Obviously, they could have fixed it by simply retrying on -EINTR. We noticed that most of the -EINTR on read(2) were due to real-time signals sent by glibc to process wide credential changes (SIGRT_1), and its signal handler had been established with SA_RESTART, in which case those calls could have been automatically restarted by the kernel. Let the kernel decide to whether or not restart the syscalls when there is a signal pending in __smb_send_rqst() by returning -ERESTARTSYS. If it can't, it will return -EINTR anyway. Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> CC: Stable <stable@vger.kernel.org> Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-22cifs: prevent truncation from long to int in wait_for_free_creditsRonnie Sahlberg
[ Upstream commit 19e888678bac8c82206eb915eaf72741b2a2615c ] The wait_event_... defines evaluate to long so we should not assign it an int as this may truncate the value. Reported-by: Marshall Midden <marshallmidden@gmail.com> Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-23cifs: Allocate encryption header through kmallocLong Li
[ Upstream commit 3946d0d04bb360acca72db5efe9ae8440012d9dc ] When encryption is used, smb2_transform_hdr is defined on the stack and is passed to the transport. This doesn't work with RDMA as the buffer needs to be DMA'ed. Fix it by using kmalloc. Signed-off-by: Long Li <longli@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-01CIFS: Fix task struct use-after-free on reconnectVincent Whitchurch
commit f1f27ad74557e39f67a8331a808b860f89254f2d upstream. The task which created the MID may be gone by the time cifsd attempts to call the callbacks on MIDs from cifs_reconnect(). This leads to a use-after-free of the task struct in cifs_wake_up_task: ================================================================== BUG: KASAN: use-after-free in __lock_acquire+0x31a0/0x3270 Read of size 8 at addr ffff8880103e3a68 by task cifsd/630 CPU: 0 PID: 630 Comm: cifsd Not tainted 5.5.0-rc6+ #119 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 Call Trace: dump_stack+0x8e/0xcb print_address_description.constprop.5+0x1d3/0x3c0 ? __lock_acquire+0x31a0/0x3270 __kasan_report+0x152/0x1aa ? __lock_acquire+0x31a0/0x3270 ? __lock_acquire+0x31a0/0x3270 kasan_report+0xe/0x20 __lock_acquire+0x31a0/0x3270 ? __wake_up_common+0x1dc/0x630 ? _raw_spin_unlock_irqrestore+0x4c/0x60 ? mark_held_locks+0xf0/0xf0 ? _raw_spin_unlock_irqrestore+0x39/0x60 ? __wake_up_common_lock+0xd5/0x130 ? __wake_up_common+0x630/0x630 lock_acquire+0x13f/0x330 ? try_to_wake_up+0xa3/0x19e0 _raw_spin_lock_irqsave+0x38/0x50 ? try_to_wake_up+0xa3/0x19e0 try_to_wake_up+0xa3/0x19e0 ? cifs_compound_callback+0x178/0x210 ? set_cpus_allowed_ptr+0x10/0x10 cifs_reconnect+0xa1c/0x15d0 ? generic_ip_connect+0x1860/0x1860 ? rwlock_bug.part.0+0x90/0x90 cifs_readv_from_socket+0x479/0x690 cifs_read_from_socket+0x9d/0xe0 ? cifs_readv_from_socket+0x690/0x690 ? mempool_resize+0x690/0x690 ? rwlock_bug.part.0+0x90/0x90 ? memset+0x1f/0x40 ? allocate_buffers+0xff/0x340 cifs_demultiplex_thread+0x388/0x2a50 ? cifs_handle_standard+0x610/0x610 ? rcu_read_lock_held_common+0x120/0x120 ? mark_lock+0x11b/0xc00 ? __lock_acquire+0x14ed/0x3270 ? __kthread_parkme+0x78/0x100 ? lockdep_hardirqs_on+0x3e8/0x560 ? lock_downgrade+0x6a0/0x6a0 ? lockdep_hardirqs_on+0x3e8/0x560 ? _raw_spin_unlock_irqrestore+0x39/0x60 ? cifs_handle_standard+0x610/0x610 kthread+0x2bb/0x3a0 ? kthread_create_worker_on_cpu+0xc0/0xc0 ret_from_fork+0x3a/0x50 Allocated by task 649: save_stack+0x19/0x70 __kasan_kmalloc.constprop.5+0xa6/0xf0 kmem_cache_alloc+0x107/0x320 copy_process+0x17bc/0x5370 _do_fork+0x103/0xbf0 __x64_sys_clone+0x168/0x1e0 do_syscall_64+0x9b/0xec0 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 0: save_stack+0x19/0x70 __kasan_slab_free+0x11d/0x160 kmem_cache_free+0xb5/0x3d0 rcu_core+0x52f/0x1230 __do_softirq+0x24d/0x962 The buggy address belongs to the object at ffff8880103e32c0 which belongs to the cache task_struct of size 6016 The buggy address is located 1960 bytes inside of 6016-byte region [ffff8880103e32c0, ffff8880103e4a40) The buggy address belongs to the page: page:ffffea000040f800 refcount:1 mapcount:0 mapping:ffff8880108da5c0 index:0xffff8880103e4c00 compound_mapcount: 0 raw: 4000000000010200 ffffea00001f2208 ffffea00001e3408 ffff8880108da5c0 raw: ffff8880103e4c00 0000000000050003 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880103e3900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880103e3980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880103e3a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880103e3a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880103e3b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== This can be reliably reproduced by adding the below delay to cifs_reconnect(), running find(1) on the mount, restarting the samba server while find is running, and killing find during the delay: spin_unlock(&GlobalMid_Lock); mutex_unlock(&server->srv_mutex); + msleep(10000); + cifs_dbg(FYI, "%s: issuing mid callbacks\n", __func__); list_for_each_safe(tmp, tmp2, &retry_list) { mid_entry = list_entry(tmp, struct mid_q_entry, qhead); Fix this by holding a reference to the task struct until the MID is freed. Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com> Signed-off-by: Steve French <stfrench@microsoft.com> CC: Stable <stable@vger.kernel.org> Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-21CIFS: Do not miss cancelled OPEN responsesPavel Shilovsky
commit 7b71843fa7028475b052107664cbe120156a2cfc upstream. When an OPEN command is cancelled we mark a mid as cancelled and let the demultiplex thread process it by closing an open handle. The problem is there is a race between a system call thread and the demultiplex thread and there may be a situation when the mid has been already processed before it is set as cancelled. Fix this by processing cancelled requests when mids are being destroyed which means that there is only one thread referencing a particular mid. Also set mids as cancelled unconditionally on their state. Cc: Stable <stable@vger.kernel.org> Tested-by: Frank Sorenson <sorenson@redhat.com> Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-21cifs: smbd: Return -EAGAIN when transport is reconnectingLong Li
commit 4357d45f50e58672e1d17648d792f27df01dfccd upstream. During reconnecting, the transport may have already been destroyed and is in the process being reconnected. In this case, return -EAGAIN to not fail and to retry this I/O. Signed-off-by: Long Li <longli@microsoft.com> Cc: stable@vger.kernel.org Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-24CIFS: Fix retry mid list corruption on reconnectsPavel Shilovsky
When the client hits reconnect it iterates over the mid pending queue marking entries for retry and moving them to a temporary list to issue callbacks later without holding GlobalMid_Lock. In the same time there is no guarantee that mids can't be removed from the temporary list or even freed completely by another thread. It may cause a temporary list corruption: [ 430.454897] list_del corruption. prev->next should be ffff98d3a8f316c0, but was 2e885cb266355469 [ 430.464668] ------------[ cut here ]------------ [ 430.466569] kernel BUG at lib/list_debug.c:51! [ 430.468476] invalid opcode: 0000 [#1] SMP PTI [ 430.470286] CPU: 0 PID: 13267 Comm: cifsd Kdump: loaded Not tainted 5.4.0-rc3+ #19 [ 430.473472] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 [ 430.475872] RIP: 0010:__list_del_entry_valid.cold+0x31/0x55 ... [ 430.510426] Call Trace: [ 430.511500] cifs_reconnect+0x25e/0x610 [cifs] [ 430.513350] cifs_readv_from_socket+0x220/0x250 [cifs] [ 430.515464] cifs_read_from_socket+0x4a/0x70 [cifs] [ 430.517452] ? try_to_wake_up+0x212/0x650 [ 430.519122] ? cifs_small_buf_get+0x16/0x30 [cifs] [ 430.521086] ? allocate_buffers+0x66/0x120 [cifs] [ 430.523019] cifs_demultiplex_thread+0xdc/0xc30 [cifs] [ 430.525116] kthread+0xfb/0x130 [ 430.526421] ? cifs_handle_standard+0x190/0x190 [cifs] [ 430.528514] ? kthread_park+0x90/0x90 [ 430.530019] ret_from_fork+0x35/0x40 Fix this by obtaining extra references for mids being retried and marking them as MID_DELETED which indicates that such a mid has been dequeued from the pending list. Also move mid cleanup logic from DeleteMidQEntry to _cifs_mid_q_entry_release which is called when the last reference to a particular mid is put. This allows to avoid any use-after-free of response buffers. The patch needs to be backported to stable kernels. A stable tag is not mentioned below because the patch doesn't apply cleanly to any actively maintained stable kernel. Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com> Reviewed-and-tested-by: David Wysochanski <dwysocha@redhat.com> Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-09-16smb3: display max smb3 requests in flight at any one timeSteve French
Displayed in /proc/fs/cifs/Stats once for each socket we are connected to. This allows us to find out what the maximum number of requests that had been in flight (at any one time). Note that /proc/fs/cifs/Stats can be reset if you want to look for maximum over a small period of time. Sample output (immediately after mount): Resources in use CIFS Session: 1 Share (unique mount targets): 2 SMB Request/Response Buffer: 1 Pool size: 5 SMB Small Req/Resp Buffer: 1 Pool size: 30 Operations (MIDs): 0 0 session 0 share reconnects Total vfs operations: 5 maximum at one time: 2 Max requests in flight: 2 1) \\localhost\scratch SMBs: 18 Bytes read: 0 Bytes written: 0 ... Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2019-09-16cifs: add a debug macro that prints \\server\share for errorsRonnie Sahlberg
Where we have a tcon available we can log \\server\share as part of the message. Only do this for the VFS log level. Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-09-16cifs: fix dereference on ses before it is null checkedColin Ian King
The assignment of pointer server dereferences pointer ses, however, this dereference occurs before ses is null checked and hence we have a potential null pointer dereference. Fix this by only dereferencing ses after it has been null checked. Addresses-Coverity: ("Dereference before null check") Fixes: 2808c6639104 ("cifs: add new debugging macro cifs_server_dbg") Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-09-16cifs: add new debugging macro cifs_server_dbgRonnie Sahlberg
which can be used from contexts where we have a TCP_Server_Info *server. This new macro will prepend the debugging string with "Server:<servername> " which will help when debugging issues on hosts with many cifs connections to several different servers. Convert a bunch of cifs_dbg(VFS) calls to cifs_server_dbg(VFS) Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-07-07smb3: minor cleanup of compound_send_recvAurelien Aptel
Trivial cleanup. Will make future multichannel code smaller as well. Signed-off-by: Aurelien Aptel <aaptel@suse.com> Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-05-12cifs: use the right include for signal_pending()Ronnie Sahlberg
This header is actually where signal_pending is defined although either would work. Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-05-07cifs: rename and clarify CIFS_ASYNC_OP and CIFS_NO_RESPRonnie Sahlberg
The flags were named confusingly. CIFS_ASYNC_OP now just means that we will not block waiting for credits to become available so we thus rename this to be CIFS_NON_BLOCKING. Change CIFS_NO_RESP to CIFS_NO_RSP_BUF to clarify that we will actually get a response from the server but we will not get/do not want a response buffer. Delete CIFSSMBNotify. This is an SMB1 function that is not used. Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2019-05-07cifs: fix credits leak for SMB1 oplock breaksRonnie Sahlberg
For SMB1 oplock breaks we would grab one credit while sending the PDU but we would never relese the credit back since we will never receive a response to this from the server. Eventuallt this would lead to a hang once all credits are leaked. Fix this by defining a new flag CIFS_NO_SRV_RSP which indicates that there is no server response to this command and thus we need to add any credits back immediately after sending the PDU. CC: Stable <stable@vger.kernel.org> #v5.0+ Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-05-07cifs: smbd: take an array of reqeusts when sending upper layer dataLong Li
To support compounding, __smb_send_rqst() now sends an array of requests to the transport layer. Change smbd_send() to take an array of requests, and send them in as few packets as possible. Signed-off-by: Long Li <longli@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com> CC: Stable <stable@vger.kernel.org>
2019-05-07SMB3: Track total time spent on roundtrips for each SMB3 commandSteve French
Also track minimum and maximum time by command in /proc/fs/cifs/Stats Signed-off-by: Steve French <stfrench@microsoft.com>
2019-03-14cifs: simplify how we handle credits in compound_send_recv()Ronnie Sahlberg
Since we can now wait for multiple requests atomically in wait_for_free_request() we can now greatly simplify the handling of the credits in this function. This fixes a potential deadlock where many concurrent compound requests could each have reserved 1 or 2 credits each but are all blocked waiting for the final credits they need to be able to issue the requests to the server. Set a default timeout of 60 seconds for compounded requests. Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2019-03-14smb3: add dynamic tracepoint for timeout waiting for creditsSteve French
To help debug credit starvation problems where we timeout waiting for server to grant the client credits. Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2019-03-14cifs: add a timeout argument to wait_for_free_creditsRonnie Sahlberg
A negative timeout is the same as the current behaviour, i.e. no timeout. Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2019-03-14cifs: prevent starvation in wait_for_free_credits for multi-credit requestsRonnie Sahlberg
Reserve the last MAX_COMPOUND credits for any request asking for >1 credit. This is to prevent future compound requests from becoming starved while waiting for potentially many requests is there is a large number of concurrent singe-credit requests. However, we need to protect from servers that are very slow to hand out new credits on new sessions so we only do this IFF there are 2*MAX_COMPOUND (arbitrary) credits already in flight. Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2019-03-14cifs: wait_for_free_credits() make it possible to wait for >=1 creditsRonnie Sahlberg
Change wait_for_free_credits() to allow waiting for >=1 credits instead of just a single credit. Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2019-03-14cifs: pass flags down into wait_for_free_credits()Ronnie Sahlberg
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2019-03-14cifs: change wait_for_free_request() to take flags as argumentRonnie Sahlberg
and compute timeout and optyp from it. Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2019-03-05CIFS: Mask off signals when sending SMB packetsPavel Shilovsky
We don't want to break SMB sessions if we receive signals when sending packets through the network. Fix it by masking off signals inside __smb_send_rqst() to avoid partial packet sends due to interrupts. Return -EINTR if a signal is pending and only a part of the packet was sent. Return a success status code if the whole packet was sent regardless of signal being pending or not. This keeps a mid entry for the request in the pending queue and allows the demultiplex thread to handle a response from the server properly. Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-03-05CIFS: Return -EAGAIN instead of -ENOTSOCKPavel Shilovsky
When we attempt to send a packet while the demultiplex thread is in the middle of cifs_reconnect() we may end up returning -ENOTSOCK to upper layers. The intent here is to retry the request once the TCP connection is up, so change it to return -EAGAIN instead. The latter error code is retryable and the upper layers will retry the request if needed. Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-03-05CIFS: Try to acquire credits at once for compound requestsPavel Shilovsky
Currently we get one credit per compound part of the request individually. This may lead to being stuck on waiting for credits if multiple compounded operations happen in parallel. Try acquire credits for all compound parts at once. Return immediately if not enough credits and too few requests are in flight currently thus narrowing the possibility of infinite waiting for credits. The more advance fix is to return right away if not enough credits for the compound request and do not look at the number of requests in flight. The caller should handle such situations by falling back to sequential execution of SMB commands instead of compounding. Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-03-05CIFS: Check for reconnects before sending compound requestsPavel Shilovsky
The reconnect might have happended after we obtained credits and before we acquired srv_mutex. Check for that under the mutex and retry a sync operation if the reconnect is detected. Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-03-05CIFS: Check for reconnects before sending async requestsPavel Shilovsky
The reconnect might have happended after we obtained credits and before we acquired srv_mutex. Check for that under the mutex and retry an async operation if the reconnect is detected. Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-03-05CIFS: Respect reconnect in non-MTU credits calculationsPavel Shilovsky
Every time after a session reconnect we don't need to account for credits obtained in previous sessions. Make use of the recently added cifs_credits structure to properly calculate credits for non-MTU requests the same way we did for MTU ones. Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-03-05CIFS: Respect reconnect in MTU credits calculationsPavel Shilovsky
Every time after a session reconnect we don't need to account for credits obtained in previous sessions. Introduce new struct cifs_credits which contains both credits value and reconnect instance of the time those credits were taken. Modify a routine that add credits back to handle the reconnect instance by assuming zero credits if the reconnect happened after the credits were obtained and before we decided to add them back due to some errors during sending. This patch fixes the MTU credits cases. The subsequent patch will handle non-MTU ones. Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-03-04CIFS: Do not skip SMB2 message IDs on send failuresPavel Shilovsky
When we hit failures during constructing MIDs or sending PDUs through the network, we end up not using message IDs assigned to the packet. The next SMB packet will skip those message IDs and continue with the next one. This behavior may lead to a server not granting us credits until we use the skipped IDs. Fix this by reverting the current ID to the original value if any errors occur before we push the packet through the network stack. This patch fixes the generic/310 test from the xfs-tests. Cc: <stable@vger.kernel.org> # 4.19.x Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-01-24CIFS: Fix credit calculations in compound mid callbackPavel Shilovsky
The current code doesn't do proper accounting for credits in SMB1 case: it adds one credit per response only if we get a complete response while it needs to return it unconditionally. Fix this and also include malformed responses for SMB2+ into accounting for credits because such responses have Credit Granted field, thus nothing prevents to get a proper credit value from them. Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-01-11CIFS: Move credit processing to mid callbacks for SMB3Pavel Shilovsky
Currently we account for credits in the thread initiating a request and waiting for a response. The demultiplex thread receives the response, wakes up the thread and the latter collects credits from the response buffer and add them to the server structure on the client. This approach is not accurate, because it may race with reconnect events in the demultiplex thread which resets the number of credits. Fix this by moving credit processing to new mid callbacks that collect credits granted by the server from the response in the demultiplex thread. Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-01-11CIFS: Fix credits calculation for cancelled requestsPavel Shilovsky
If a request is cancelled, we can't assume that the server returns 1 credit back. Instead we need to wait for a response and process the number of credits granted by the server. Create a separate mid callback for cancelled request, parse the number of credits in a response buffer and add them to the client's credits. If the didn't get a response (no response buffer available) assume 0 credits granted. The latter most probably happens together with session reconnect, so the client's credits are adjusted anyway. Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-01-11CIFS: Do not hide EINTR after sending network packetsPavel Shilovsky
Currently we hide EINTR code returned from sock_sendmsg() and return 0 instead. This makes a caller think that we successfully completed the network operation which is not true. Fix this by properly returning EINTR to callers. Cc: <stable@vger.kernel.org> Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-01-10CIFS: Fix credit computation for compounded requestsPavel Shilovsky
In SMB3 protocol every part of the compound chain consumes credits individually, so we need to call wait_for_free_credits() for each of the PDUs in the chain. If an operation is interrupted, we must ensure we return all credits taken from the server structure back. Without this patch server can sometimes disconnect the session due to credit mismatches, especially when first operation(s) are large writes. Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com> CC: Stable <stable@vger.kernel.org>
2019-01-10CIFS: Do not set credits to 1 if the server didn't grant anythingPavel Shilovsky
Currently we reset the number of total credits granted by the server to 1 if the server didn't grant us anything int the response. This violates the SMB3 protocol - we need to trust the server and use the credit values from the response. Fix this by removing the corresponding code. Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com> CC: Stable <stable@vger.kernel.org>
2018-12-23cifs: smb2 commands can not be negative, remove confusing checkSteve French
As Coverity points out le16_to_cpu(midEntry->Command) can not be less than zero. Detected by CoverityScan, CID#1438650 ("Macro compares unsigned to 0") Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
2018-11-01Merge branch 'work.afs' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull AFS updates from Al Viro: "AFS series, with some iov_iter bits included" * 'work.afs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (26 commits) missing bits of "iov_iter: Separate type from direction and use accessor functions" afs: Probe multiple fileservers simultaneously afs: Fix callback handling afs: Eliminate the address pointer from the address list cursor afs: Allow dumping of server cursor on operation failure afs: Implement YFS support in the fs client afs: Expand data structure fields to support YFS afs: Get the target vnode in afs_rmdir() and get a callback on it afs: Calc callback expiry in op reply delivery afs: Fix FS.FetchStatus delivery from updating wrong vnode afs: Implement the YFS cache manager service afs: Remove callback details from afs_callback_break struct afs: Commit the status on a new file/dir/symlink afs: Increase to 64-bit volume ID and 96-bit vnode ID for YFS afs: Don't invoke the server to read data beyond EOF afs: Add a couple of tracepoints to log I/O errors afs: Handle EIO from delivery function afs: Fix TTL on VL server and address lists afs: Implement VL server rotation afs: Improve FS server rotation error handling ...
2018-10-24smb3: add debug for unexpected mid cancellationSteve French
We have hit this intermittently, increase the verbosity of warning message on unexpected mid cancellation. Signed-off-by: Steve French <stfrench@microsoft.com>
2018-10-23CIFS: Print message when attempting a mountRodrigo Freire
Currently, no messages are printed when mounting a CIFS filesystem and no debug configuration is enabled. However, a CIFS mount information is valuable when troubleshooting and/or forensic analyzing a system and finding out if was a CIFS endpoint mount attempted. Other filesystems such as XFS, EXT* does issue a printk() when mounting their filesystems. A terse log message is printed only if cifsFYI is not enabled. Otherwise, the default full debug message is printed. In order to not clutter and classify correctly the event messages, these are logged as KERN_INFO level. Sample mount operations: [root@corinthians ~]# mount -o user=administrator //172.25.250.18/c$ /mnt (non-existent system) [root@corinthians ~]# mount -o user=administrator //172.25.250.19/c$ /mnt (Valid system) Kernel message log for the mount operations: [ 450.464543] CIFS: Attempting to mount //172.25.250.18/c$ [ 456.478186] CIFS VFS: Error connecting to socket. Aborting operation. [ 456.478381] CIFS VFS: cifs_mount failed w/return code = -113 [ 467.688866] CIFS: Attempting to mount //172.25.250.19/c$ Signed-off-by: Rodrigo Freire <rfreire@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2018-10-23smb3: add way to control slow response threshold for logging and statsSteve French
/proc/fs/cifs/Stats when CONFIG_CIFS_STATS2 is enabled logs 'slow' responses, but depending on the server you are debugging a one second timeout may be too fast, so allow setting it to a larger number of seconds via new module parameter /sys/module/cifs/parameters/slow_rsp_threshold or via modprobe: slow_rsp_threshold:Amount of time (in seconds) to wait before logging that a response is delayed. Default: 1 (if set to 0 disables msg). (uint) Recommended values are 0 (disabled) to 32767 (9 hours) with the default remaining as 1 second. Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Aurelien Aptel <aaptel@suse.com>