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path: root/fs/cifs/transport.c
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2020-05-28tcp: add tcp_sock_set_corkChristoph Hellwig
Add a helper to directly set the TCP_CORK sockopt from kernel space without going through a fake uaccess. Cleanup the callers to avoid pointless wrappers now that this is a simple function call. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-29cifs: Allocate encryption header through kmallocLong Li
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>
2020-01-26CIFS: Fix task struct use-after-free on reconnectVincent Whitchurch
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>
2019-11-25cifs: try opening channels after mountingAurelien Aptel
After doing mount() successfully we call cifs_try_adding_channels() which will open as many channels as it can. Channels are closed when the master session is closed. The master connection becomes the first channel. ,-------------> global cifs_tcp_ses_list <-------------------------. | | '- TCP_Server_Info <--> TCP_Server_Info <--> TCP_Server_Info <-' (master con) (chan#1 con) (chan#2 con) | ^ ^ ^ v '--------------------|--------------------' cifs_ses | - chan_count = 3 | - chans[] ---------------------' - smb3signingkey[] (master signing key) Note how channel connections don't have sessions. That's because cifs_ses can only be part of one linked list (list_head are internal to the elements). For signing keys, each channel has its own signing key which must be used only after the channel has been bound. While it's binding it must use the master session signing key. For encryption keys, since channel connections do not have sessions attached we must now find matching session by looping over all sessions in smb2_get_enc_key(). Each channel is opened like a regular server connection but at the session setup request step it must set the SMB2_SESSION_REQ_FLAG_BINDING flag and use the session id to bind to. Finally, while sending in compound_send_recv() for requests that aren't negprot, ses-setup or binding related, use a channel by cycling through the available ones (round-robin). Signed-off-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-11-25cifs: add server paramAurelien Aptel
As we get down to the transport layer, plenty of functions are passed the session pointer and assume the transport to use is ses->server. Instead we modify those functions to pass (ses, server) so that we can decouple the session from the server. Signed-off-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-11-25cifs: smbd: Return -EAGAIN when transport is reconnectingLong Li
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>
2019-11-25CIFS: Do not miss cancelled OPEN responsesPavel Shilovsky
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>
2019-11-25cifs: rename a variable in SendReceive()Dan Carpenter
Smatch gets confused because we sometimes refer to "server->srv_mutex" and sometimes to "sess->server->srv_mutex". They refer to the same lock so let's just make this consistent. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Steve French <stfrench@microsoft.com>
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>
2018-10-23cifs: fix a credits leak for compund commandsRonnie Sahlberg
When processing the mids for compounds we would only add credits based on the last successful mid in the compound which would leak credits and eventually triggering a re-connect. Fix this by splitting the mid processing part into two loops instead of one where the first loop just waits for all mids and then counts how many credits we were granted for the whole compound. Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2018-10-24iov_iter: Separate type from direction and use accessor functionsDavid Howells
In the iov_iter struct, separate the iterator type from the iterator direction and use accessor functions to access them in most places. Convert a bunch of places to use switch-statements to access them rather then chains of bitwise-AND statements. This makes it easier to add further iterator types. Also, this can be more efficient as to implement a switch of small contiguous integers, the compiler can use ~50% fewer compare instructions than it has to use bitwise-and instructions. Further, cease passing the iterator type into the iterator setup function. The iterator function can set that itself. Only the direction is required. Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-02cifs: only wake the thread for the very last PDU in a compoundRonnie Sahlberg
For compounded PDUs we whould only wake the waiting thread for the very last PDU of the compound. We do this so that we are guaranteed that the demultiplex_thread will not process or access any of those MIDs any more once the send/recv thread starts processing. Else there is a race where at the end of the send/recv processing we will try to delete all the mids of the compound. If the multiplex thread still has other mids to process at this point for this compound this can lead to an oops. Needed to fix recent commit: commit 730928c8f4be88e9d6a027a16b1e8fa9c59fc077 ("cifs: update smb2_queryfs() to use compounding") Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2018-10-02cifs: add a warning if we try to to dequeue a deleted midRonnie Sahlberg
cifs_delete_mid() is called once we are finished handling a mid and we expect no more work done on this mid. Needed to fix recent commit: commit 730928c8f4be88e9d6a027a16b1e8fa9c59fc077 ("cifs: update smb2_queryfs() to use compounding") Add a warning if someone tries to dequeue a mid that has already been flagged to be deleted. Also change list_del() to list_del_init() so that if we have similar bugs resurface in the future we will not oops. Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2018-08-09cifs: update receive_encrypted_standard to handle compounded responsesRonnie Sahlberg
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Paulo Alcantara <palcantara@suse.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>