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* CIFS: fix oplock break deadlocksRabin Vincent2017-05-031-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the final cifsFileInfo_put() is called from cifsiod and an oplock break work is queued, lockdep complains loudly: ============================================= [ INFO: possible recursive locking detected ] 4.11.0+ #21 Not tainted --------------------------------------------- kworker/0:2/78 is trying to acquire lock: ("cifsiod"){++++.+}, at: flush_work+0x215/0x350 but task is already holding lock: ("cifsiod"){++++.+}, at: process_one_work+0x255/0x8e0 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock("cifsiod"); lock("cifsiod"); *** DEADLOCK *** May be due to missing lock nesting notation 2 locks held by kworker/0:2/78: #0: ("cifsiod"){++++.+}, at: process_one_work+0x255/0x8e0 #1: ((&wdata->work)){+.+...}, at: process_one_work+0x255/0x8e0 stack backtrace: CPU: 0 PID: 78 Comm: kworker/0:2 Not tainted 4.11.0+ #21 Workqueue: cifsiod cifs_writev_complete Call Trace: dump_stack+0x85/0xc2 __lock_acquire+0x17dd/0x2260 ? match_held_lock+0x20/0x2b0 ? trace_hardirqs_off_caller+0x86/0x130 ? mark_lock+0xa6/0x920 lock_acquire+0xcc/0x260 ? lock_acquire+0xcc/0x260 ? flush_work+0x215/0x350 flush_work+0x236/0x350 ? flush_work+0x215/0x350 ? destroy_worker+0x170/0x170 __cancel_work_timer+0x17d/0x210 ? ___preempt_schedule+0x16/0x18 cancel_work_sync+0x10/0x20 cifsFileInfo_put+0x338/0x7f0 cifs_writedata_release+0x2a/0x40 ? cifs_writedata_release+0x2a/0x40 cifs_writev_complete+0x29d/0x850 ? preempt_count_sub+0x18/0xd0 process_one_work+0x304/0x8e0 worker_thread+0x9b/0x6a0 kthread+0x1b2/0x200 ? process_one_work+0x8e0/0x8e0 ? kthread_create_on_node+0x40/0x40 ret_from_fork+0x31/0x40 This is a real warning. Since the oplock is queued on the same workqueue this can deadlock if there is only one worker thread active for the workqueue (which will be the case during memory pressure when the rescuer thread is handling it). Furthermore, there is at least one other kind of hang possible due to the oplock break handling if there is only worker. (This can be reproduced without introducing memory pressure by having passing 1 for the max_active parameter of cifsiod.) cifs_oplock_break() can wait indefintely in the filemap_fdatawait() while the cifs_writev_complete() work is blocked: sysrq: SysRq : Show Blocked State task PC stack pid father kworker/0:1 D 0 16 2 0x00000000 Workqueue: cifsiod cifs_oplock_break Call Trace: __schedule+0x562/0xf40 ? mark_held_locks+0x4a/0xb0 schedule+0x57/0xe0 io_schedule+0x21/0x50 wait_on_page_bit+0x143/0x190 ? add_to_page_cache_lru+0x150/0x150 __filemap_fdatawait_range+0x134/0x190 ? do_writepages+0x51/0x70 filemap_fdatawait_range+0x14/0x30 filemap_fdatawait+0x3b/0x40 cifs_oplock_break+0x651/0x710 ? preempt_count_sub+0x18/0xd0 process_one_work+0x304/0x8e0 worker_thread+0x9b/0x6a0 kthread+0x1b2/0x200 ? process_one_work+0x8e0/0x8e0 ? kthread_create_on_node+0x40/0x40 ret_from_fork+0x31/0x40 dd D 0 683 171 0x00000000 Call Trace: __schedule+0x562/0xf40 ? mark_held_locks+0x29/0xb0 schedule+0x57/0xe0 io_schedule+0x21/0x50 wait_on_page_bit+0x143/0x190 ? add_to_page_cache_lru+0x150/0x150 __filemap_fdatawait_range+0x134/0x190 ? do_writepages+0x51/0x70 filemap_fdatawait_range+0x14/0x30 filemap_fdatawait+0x3b/0x40 filemap_write_and_wait+0x4e/0x70 cifs_flush+0x6a/0xb0 filp_close+0x52/0xa0 __close_fd+0xdc/0x150 SyS_close+0x33/0x60 entry_SYSCALL_64_fastpath+0x1f/0xbe Showing all locks held in the system: 2 locks held by kworker/0:1/16: #0: ("cifsiod"){.+.+.+}, at: process_one_work+0x255/0x8e0 #1: ((&cfile->oplock_break)){+.+.+.}, at: process_one_work+0x255/0x8e0 Showing busy workqueues and worker pools: workqueue cifsiod: flags=0xc pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/1 in-flight: 16:cifs_oplock_break delayed: cifs_writev_complete, cifs_echo_request pool 0: cpus=0 node=0 flags=0x0 nice=0 hung=0s workers=3 idle: 750 3 Fix these problems by creating a a new workqueue (with a rescuer) for the oplock break work. Signed-off-by: Rabin Vincent <rabinv@axis.com> Signed-off-by: Steve French <smfrench@gmail.com> CC: Stable <stable@vger.kernel.org>
* Handle mismatched open callsSachin Prabhu2017-04-071-0/+46
| | | | | | | | | | | | | | | | | | A signal can interrupt a SendReceive call which result in incoming responses to the call being ignored. This is a problem for calls such as open which results in the successful response being ignored. This results in an open file resource on the server. The patch looks into responses which were cancelled after being sent and in case of successful open closes the open fids. For this patch, the check is only done in SendReceive2() RH-bz: 1403319 Signed-off-by: Sachin Prabhu <sprabhu@redhat.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com> Cc: Stable <stable@vger.kernel.org>
* CIFS: Separate SMB2 header structurePavel Shilovsky2017-02-011-28/+33
| | | | | | | | | In order to support compounding and encryption we need to separate RFC1001 length field and SMB2 header structure because the protocol treats them differently. This change will allow to simplify parsing of such complex SMB2 packets further. Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
* Clarify locking of cifs file and tcon structures and make more granularSteve French2016-10-121-8/+8
| | | | | | | | | | | | | | | | | | | Remove the global file_list_lock to simplify cifs/smb3 locking and have spinlocks that more closely match the information they are protecting. Add new tcon->open_file_lock and file->file_info_lock spinlocks. Locks continue to follow a heirachy, cifs_socket --> cifs_ses --> cifs_tcon --> cifs_file where global tcp_ses_lock still protects socket and cifs_ses, while the the newer locks protect the lower level structure's information (tcon and cifs_file respectively). CC: Stable <stable@vger.kernel.org> Signed-off-by: Steve French <steve.french@primarydata.com> Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Reviewed-by: Germano Percossi <germano.percossi@citrix.com>
* Prepare for encryption support (first part). Add decryption and encryption ↵Steve French2016-01-141-6/+30
| | | | | | | key generation. Thanks to Metze for helping with this. Reviewed-by: Stefan Metzmacher <metze@samba.org> Signed-off-by: Steve French <steve.french@primarydata.com>
* VFS: normal filesystems (and lustre): d_inode() annotationsDavid Howells2015-04-151-2/+2
| | | | | | | that's the bulk of filesystem drivers dealing with inodes of their own Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Fix coverity warningSteve French2015-04-011-1/+1
| | | | | | | | | | | | | | Coverity reports a warning for referencing the beginning of the SMB2/SMB3 frame using the ProtocolId field as an array. Although it works the same either way, this patch should quiet the warning and might be a little clearer. Reported by Coverity (CID 741269) Signed-off-by: Steve French <smfrench@gmail.com> Acked-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com> Acked-by: Sachin Prabhu <sprabhu@redhat.com> Reviewed-by: Jeff Layton <jlayton@poochiereds.net>
* Convert MessageID in smb2_hdr to LESachin Prabhu2014-12-141-5/+7
| | | | | | | | | | | | | | We have encountered failures when When testing smb2 mounts on ppc64 machines when using both Samba as well as Windows 2012. On poking around, the problem was determined to be caused by the high endian MessageID passed in the header for smb2. On checking the corresponding MID for smb1 is converted to LE before being sent on the wire. We have tested this patch successfully on a ppc64 machine. Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
* fs/cifs: remove obsolete __constantFabian Frederick2014-12-101-19/+19
| | | | | | | | | | | Replace all __constant_foo to foo() except in smb2status.h (1700 lines to update). Signed-off-by: Fabian Frederick <fabf@skynet.be> Cc: Steve French <sfrench@samba.org> Cc: Jeff Layton <jlayton@poochiereds.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Allow conversion of characters in Mac remap range (part 2)Steve French2014-10-161-3/+9
| | | | | | | | | The previous patch allowed remapping reserved characters from directory listenings, this patch adds conversion the other direction, allowing opening of files with any of the seven reserved characters. Signed-off-by: Steve French <smfrench@gmail.com> Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
* [CIFS] Workaround MacOS server problem with SMB2.1 writeSteve French2014-08-151-1/+16
| | | | | | | | | | | | | | | | | | response Writes fail to Mac servers with SMB2.1 mounts (works with cifs though) due to them sending an incorrect RFC1001 length for the SMB2.1 Write response. Workaround this problem. MacOS server sends a write response with 3 bytes of pad beyond the end of the SMB itself. The RFC1001 length is 3 bytes more than the sum of the SMB2.1 header length + the write reponse. Incorporate feedback from Jeff and JRA to allow servers to send a tcp frame that is even more than three bytes too long (ie much longer than the SMB2/SMB3 request that it contains) but we do log it once now. In the earlier version of the patch I had limited how far off the length field could be before we fail the request. Signed-off-by: Steve French <smfrench@gmail.com>
* [CIFS] Fix incorrect hex vs. decimal in some debug print statementsSteve French2014-08-021-3/+3
| | | | | | | | | | | Joe Perches and Hans Wennborg noticed that various places in the kernel were printing decimal numbers with 0x prefix. printk("0x%d") or equivalent This fixes the instances of this in the cifs driver. CC: Hans Wennborg <hans@hanshq.net> CC: Joe Perches <joe@perches.com> Signed-off-by: Steve French <smfrench@gmail.com>
* cifs: Wait for writebacks to complete before attempting write.Sachin Prabhu2014-04-161-3/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Problem reported in Red Hat bz 1040329 for strict writes where we cache only when we hold oplock and write direct to the server when we don't. When we receive an oplock break, we first change the oplock value for the inode in cifsInodeInfo->oplock to indicate that we no longer hold the oplock before we enqueue a task to flush changes to the backing device. Once we have completed flushing the changes, we return the oplock to the server. There are 2 ways here where we can have data corruption 1) While we flush changes to the backing device as part of the oplock break, we can have processes write to the file. These writes check for the oplock, find none and attempt to write directly to the server. These direct writes made while we are flushing from cache could be overwritten by data being flushed from the cache causing data corruption. 2) While a thread runs in cifs_strict_writev, the machine could receive and process an oplock break after the thread has checked the oplock and found that it allows us to cache and before we have made changes to the cache. In that case, we end up with a dirty page in cache when we shouldn't have any. This will be flushed later and will overwrite all subsequent writes to the part of the file represented by this page. Before making any writes to the server, we need to confirm that we are not in the process of flushing data to the server and if we are, we should wait until the process is complete before we attempt the write. We should also wait for existing writes to complete before we process an oplock break request which changes oplock values. We add a version specific downgrade_oplock() operation to allow for differences in the oplock values set for the different smb versions. Cc: stable@vger.kernel.org Signed-off-by: Sachin Prabhu <sprabhu@redhat.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru> Signed-off-by: Steve French <smfrench@gmail.com>
* CIFS: Respect epoch value from create lease context v2Pavel Shilovsky2013-09-091-2/+4
| | | | | | | that force a client to purge cache pages when a server requests it. Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org> Signed-off-by: Steve French <smfrench@gmail.com>
* CIFS: Store lease state itself rather than a mapped oplock valuePavel Shilovsky2013-09-091-19/+11
| | | | | | | and separate smb20_operations struct. Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org> Signed-off-by: Steve French <smfrench@gmail.com>
* CIFS: Replace clientCanCache* bools with an integerPavel Shilovsky2013-09-081-3/+3
| | | | | | | that prepare the code to handle different types of SMB2 leases. Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org> Signed-off-by: Steve French <smfrench@gmail.com>
* CIFS: Fix missing lease breakPavel Shilovsky2013-09-081-69/+80
| | | | | | | | | | | If a server sends a lease break to a connection that doesn't have opens with a lease key specified in the server response, we can't find an open file to send an ack. Fix this by walking through all connections we have. Cc: <stable@vger.kernel.org> Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org> Signed-off-by: Steve French <smfrench@gmail.com>
* CIFS: Fix a memory leak when a lease break comesPavel Shilovsky2013-09-081-0/+1
| | | | | | | | | | This happens when we receive a lease break from a server, then find an appropriate lease key in opened files and schedule the oplock_break slow work. lw pointer isn't freed in this case. Cc: <stable@vger.kernel.org> Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org> Signed-off-by: Steve French <smfrench@gmail.com>
* CIFS: Implement follow_link for SMB2Pavel Shilovsky2013-09-081-0/+4
| | | | | | | | that allows to access files through symlink created on a server. Acked-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org> Signed-off-by: Steve French <smfrench@gmail.com>
* SMB2 FSCTL and IOCTL worker functionSteve French2013-06-261-0/+4
| | | | | | | | | | | | | | | | | | | | | | | This worker function is needed to send SMB2 fsctl (and ioctl) requests including: validating negotiation info (secure negotiate) querying the servers network interfaces copy offload (refcopy) Followon patches for the above three will use this. This patch also does general validation of the response. In the future, as David Disseldorp notes, for the copychunk ioctl case, we will want to enhance the response processing to allow returning the chunk request limits to the caller (even though the server returns an error, in that case we would return data that the caller could use - see 2.2.32.1). See MS-SMB2 Section 2.2.31 for more details on format of fsctl. Acked-by: Pavel Shilovsky <piastry@etersoft.ru> Signed-off-by: Steve French <smfrench@gmail.com>
* [CIFS] cifs: Rename cERROR and cFYI to cifs_dbgJoe Perches2013-05-041-48/+48
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's not obvious from reading the macro names that these macros are for debugging. Convert the names to a single more typical kernel style cifs_dbg macro. cERROR(1, ...) -> cifs_dbg(VFS, ...) cFYI(1, ...) -> cifs_dbg(FYI, ...) cFYI(DBG2, ...) -> cifs_dbg(NOISY, ...) Move the terminating format newline from the macro to the call site. Add CONFIG_CIFS_DEBUG function cifs_vfs_err to emit the "CIFS VFS: " prefix for VFS messages. Size is reduced ~ 1% when CONFIG_CIFS_DEBUG is set (default y) $ size fs/cifs/cifs.ko* text data bss dec hex filename 265245 2525 132 267902 4167e fs/cifs/cifs.ko.new 268359 2525 132 271016 422a8 fs/cifs/cifs.ko.old Other miscellaneous changes around these conversions: o Miscellaneous typo fixes o Add terminating \n's to almost all formats and remove them from the macros to be more kernel style like. A few formats previously had defective \n's o Remove unnecessary OOM messages as kmalloc() calls dump_stack o Coalesce formats to make grep easier, added missing spaces when coalescing formats o Use %s, __func__ instead of embedded function name o Removed unnecessary "cifs: " prefixes o Convert kzalloc with multiply to kcalloc o Remove unused cifswarn macro Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com>
* Trivial endian fixesSteve French2012-09-241-2/+3
| | | | | | | | Some trivial endian fixes for the SMB2 code. One warning remains which I asked Pavel to look at. Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru> Signed-off-by: Steve French <smfrench@gmail.com>
* CIFS: Fix fast lease break after open problemPavel Shilovsky2012-09-241-5/+69
| | | | | | | | | | | | Now we walk though cifsFileInfo's list for every incoming lease break and look for an equivalent there. That approach misses lease breaks that come just after an open response - we don't have time to populate new cifsFileInfo structure to the list. Fix this by adding new list of pending opens and look for a lease there if we didn't find it in the list of cifsFileInfo structures. Signed-off-by: Pavel Shilovsky <pshilovsky@etersoft.ru> Signed-off-by: Steve French <sfrench@us.ibm.com>
* CIFS: Add SMB2.1 lease break supportPavel Shilovsky2012-09-241-1/+89
| | | | | Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org> Signed-off-by: Steve French <sfrench@us.ibm.com>
* CIFS: Add oplock break support for SMB2Pavel Shilovsky2012-09-241-2/+74
| | | | | Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org> Signed-off-by: Steve French <smfrench@gmail.com>
* CIFS: Add readdir support for SMB2Pavel Shilovsky2012-09-241-1/+7
| | | | | Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org> Signed-off-by: Steve French <smfrench@gmail.com>
* CIFS: Add SMB2 support for cifs_iovec_readPavel Shilovsky2012-09-241-0/+3
| | | | | Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org> Signed-off-by: Steve French <smfrench@gmail.com>
* CIFS: Fix log messages in packet checking for SMB2Pavel Shilovsky2012-08-191-7/+9
| | | | | Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org> Signed-off-by: Steve French <smfrench@gmail.com>
* CIFS: Query SMB2 inode infoPavel Shilovsky2012-07-241-1/+6
| | | | | Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru> Signed-off-by: Steve French <smfrench@gmail.com>
* CIFS: Add SMB2 support for is_path_accessiblePavel Shilovsky2012-07-241-0/+25
| | | | | | | that needs for a successful mount through SMB2 protocol. Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru> Signed-off-by: Steve French <smfrench@gmail.com>
* CIFS: Add session setup/logoff capability for SMB2Pavel Shilovsky2012-07-241-0/+5
| | | | | Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru> Signed-off-by: Steve French <smfrench@gmail.com>
* CIFS: Add capability to send SMB2 negotiate messagePavel Shilovsky2012-07-241-1/+6
| | | | | | | | | and add negotiate request type to let set_credits know that we are only on negotiate stage and no need to make a decision about disabling echos and oplocks. Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru> Signed-off-by: Steve French <smfrench@gmail.com>
* CIFS: Make demultiplex_thread work with SMB2 codePavel Shilovsky2012-07-241-0/+307
Now we can process SMB2 messages: check message, get message id and wakeup awaiting routines. Signed-off-by: Pavel Shilovsky <piastryyy@gmail.com> Signed-off-by: Steve French <smfrench@gmail.com>