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path: root/fs/cifs/cifs_swn.c
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2022-10-05smb3: add dynamic trace points for tree disconnectSteve French1-6/+6
Needed this for debugging a failing xfstest. Also change camel case for "treeName" to "tree_name" in tcon struct. Example trace output (from "trace-cmd record -e smb3_tdis*"): umount-9718 [006] ..... 5909.780244: smb3_tdis_enter: xid=206 sid=0xcf38894e tid=0x3d0b8cf8 path=\\localhost\test umount-9718 [007] ..... 5909.780878: smb3_tdis_done: xid=206 sid=0xcf38894e tid=0x3d0b8cf8 Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com>
2022-06-01cifs: fix potential deadlock in direct reclaimVincent Whitchurch1-2/+2
The srv_mutex is used during writeback so cifs should ensure that allocations done when that mutex is held are done with GFP_NOFS, to avoid having direct reclaim ending up waiting for the same mutex and causing a deadlock. This is detected by lockdep with the splat below: ====================================================== WARNING: possible circular locking dependency detected 5.18.0 #70 Not tainted ------------------------------------------------------ kswapd0/49 is trying to acquire lock: ffff8880195782e0 (&tcp_ses->srv_mutex){+.+.}-{3:3}, at: compound_send_recv but task is already holding lock: ffffffffa98e66c0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (fs_reclaim){+.+.}-{0:0}: fs_reclaim_acquire kmem_cache_alloc_trace __request_module crypto_alg_mod_lookup crypto_alloc_tfm_node crypto_alloc_shash cifs_alloc_hash smb311_crypto_shash_allocate smb311_update_preauth_hash compound_send_recv cifs_send_recv SMB2_negotiate smb2_negotiate cifs_negotiate_protocol cifs_get_smb_ses cifs_mount cifs_smb3_do_mount smb3_get_tree vfs_get_tree path_mount __x64_sys_mount do_syscall_64 entry_SYSCALL_64_after_hwframe -> #0 (&tcp_ses->srv_mutex){+.+.}-{3:3}: __lock_acquire lock_acquire __mutex_lock mutex_lock_nested compound_send_recv cifs_send_recv SMB2_write smb2_sync_write cifs_write cifs_writepage_locked cifs_writepage shrink_page_list shrink_lruvec shrink_node balance_pgdat kswapd kthread ret_from_fork other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(fs_reclaim); lock(&tcp_ses->srv_mutex); lock(fs_reclaim); lock(&tcp_ses->srv_mutex); *** DEADLOCK *** 1 lock held by kswapd0/49: #0: ffffffffa98e66c0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat stack backtrace: CPU: 2 PID: 49 Comm: kswapd0 Not tainted 5.18.0 #70 Call Trace: <TASK> dump_stack_lvl dump_stack print_circular_bug.cold check_noncircular __lock_acquire lock_acquire __mutex_lock mutex_lock_nested compound_send_recv cifs_send_recv SMB2_write smb2_sync_write cifs_write cifs_writepage_locked cifs_writepage shrink_page_list shrink_lruvec shrink_node balance_pgdat kswapd kthread ret_from_fork </TASK> Fix this by using the memalloc_nofs_save/restore APIs around the places where the srv_mutex is held. Do this in a wrapper function for the lock/unlock of the srv_mutex, and rename the srv_mutex to avoid missing call sites in the conversion. Note that there is another lockdep warning involving internal crypto locks, which was masked by this problem and is visible after this fix, see the discussion in this thread: https://lore.kernel.org/all/20220523123755.GA13668@axis.com/ Link: https://lore.kernel.org/r/CANT5p=rqcYfYMVHirqvdnnca4Mo+JQSw5Qu12v=kPfpk5yhhmg@mail.gmail.com/ Reported-by: Shyam Prasad N <nspmangalore@gmail.com> Suggested-by: Lars Persson <larper@axis.com> Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com> Reviewed-by: Enzo Matsumiya <ematsumiya@suse.de> Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2022-03-19cifs: use a different reconnect helper for non-cifsd threadsShyam Prasad N1-3/+3
The cifs_demultiplexer_thread should only call cifs_reconnect. If any other thread wants to trigger a reconnect, they can do so by updating the server tcpStatus to CifsNeedReconnect. The last patch attempted to use the same helper function for both types of threads, but that causes other issues with lock dependencies. This patch creates a new helper for non-cifsd threads, that will indicate to cifsd that the server needs reconnect. Fixes: 2a05137a0575 ("cifs: mark sessions for reconnection in helper function") Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2022-02-09cifs: call helper functions for marking channels for reconnectShyam Prasad N1-3/+3
cifs_mark_tcp_ses_conns_for_reconnect helper function is now meant to be used by any of the threads to mark a channel (or all the channels) for reconnect. Replace all such manual changes to tcpStatus to use this helper function, which takes care that the right channels, smb sessions and tcons are marked for reconnect. Also includes one line minor change Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2022-01-19cifs: cifs_ses_mark_for_reconnect should also update reconnect bitsShyam Prasad N1-6/+3
Recent restructuring of cifs_reconnect introduced a helper func named cifs_ses_mark_for_reconnect, which updates the state of tcp session for all the channels of a session for reconnect. However, this does not update the session state and chans_need_reconnect bitmask. This change fixes that. Also, cifs_mark_tcp_sess_for_reconnect should mark set the bitmask for all channels when the whole session is marked for reconnect. Fixed that here too. Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2022-01-08cifs: take cifs_tcp_ses_lock for status checksShyam Prasad N1-2/+2
While checking/updating status for tcp ses, smb ses or tcon, we take GlobalMid_Lock. This doesn't make any sense. Replaced it with cifs_tcp_ses_lock. Ideally, we should take a spin lock per struct. But since tcp ses, smb ses and tcon objects won't add up to a lot, I think there should not be too much contention. Also, in few other places, these are checked without locking. Added locking for these. Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2021-11-16cifs: introduce cifs_ses_mark_for_reconnect() helperPaulo Alcantara1-14/+2
Use new cifs_ses_mark_for_reconnect() helper to mark all session channels for reconnect instead of duplicating it in different places. Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com>
2021-08-25cifs: remove support for NTLM and weaker authentication algorithmsRonnie Sahlberg1-2/+0
for SMB1. This removes the dependency to DES. Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2021-06-21smb3: fix uninitialized value for port in witness protocol moveSteve French1-7/+3
Although in practice this can not occur (since IPv4 and IPv6 are the only two cases currently supported), it is cleaner to avoid uninitialized variable warnings. Addresses smatch warning: fs/cifs/cifs_swn.c:468 cifs_swn_store_swn_addr() error: uninitialized symbol 'port'. Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> CC: Samuel Cabrero <scabrero@suse.de> Signed-off-by: Steve French <stfrench@microsoft.com>
2021-03-19fs/cifs/: fix misspellings using codespell toolLiu xuzhi1-1/+1
A typo is found out by codespell tool in 251th lines of cifs_swn.c: $ codespell ./fs/cifs/ ./cifs_swn.c:251: funciton ==> function Fix a typo found by codespell. Signed-off-by: Liu xuzhi <liu.xuzhi@zte.com.cn> Signed-off-by: Steve French <stfrench@microsoft.com>
2021-02-20cifs: Fix inconsistent IS_ERR and PTR_ERRYueHaibing1-1/+1
Fix inconsistent IS_ERR and PTR_ERR in cifs_find_swn_reg(). The proper pointer to be passed as argument to PTR_ERR() is share_name. This bug was detected with the help of Coccinelle. Fixes: bf80e5d4259a ("cifs: Send witness register and unregister commands to userspace daemon") Signed-off-by: YueHaibing <yuehaibing@huawei.com> Reviewed-by: Samuel Cabrero <scabrero@suse.de> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-18cifs: Re-indent cifs_swn_reconnect()Dan Carpenter1-31/+33
This code is slightly nicer if we flip the cifs_sockaddr_equal() around and pull all the code in one tab. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Samuel Cabrero <scabrero@suse.de> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-18cifs: Unlock on errors in cifs_swn_reconnect()Dan Carpenter1-6/+7
There are three error paths which need to unlock before returning. Fixes: 121d947d4fe1 ("cifs: Handle witness client move notification") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Samuel Cabrero <scabrero@suse.de> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-18cifs: Delete a stray unlock in cifs_swn_reconnect()Dan Carpenter1-2/+0
The unlock is done in the caller, this is a stray which leads to a double unlock bug. Fixes: bf80e5d4259a ("cifs: Send witness register and unregister commands to userspace daemon") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Samuel Cabrero <scabrero@suse.de> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-18Merge tag '5.11-rc-smb3' of git://git.samba.org/sfrench/cifs-2.6Linus Torvalds1-0/+694
Pull cifs updates from Steve French: "The largest part are for support of the newer mount API which has been needed for cifs/smb3 mounts for a long time due to the new API's better handling of remount, and better error reporting. There are three additional small cleanup patches for this being tested, that are not included yet. This series also includes addition of support for the SMB3 witness protocol which can provide important notifications from the server to client on server address or export or network changes. This can be useful for example in order to be notified before the failure - when a server's IP address changes (in the future it will allow us to support server notifications of when a share is moved). It also includes three patches for stable e.g. some that better handle some confusing error messages during session establishment" * tag '5.11-rc-smb3' of git://git.samba.org/sfrench/cifs-2.6: (55 commits) cifs: update internal module version number cifs: Fix support for remount when not changing rsize/wsize cifs: handle "guest" mount parameter cifs: correct four aliased mount parms to allow use of previous names cifs: Tracepoints and logs for tracing credit changes. cifs: fix use after free in cifs_smb3_do_mount() cifs: fix rsize/wsize to be negotiated values cifs: Fix some error pointers handling detected by static checker smb3: remind users that witness protocol is experimental cifs: update super_operations to show_devname cifs: fix uninitialized variable in smb3_fs_context_parse_param cifs: update mnt_cifs_flags during reconfigure cifs: move update of flags into a separate function cifs: remove ctx argument from cifs_setup_cifs_sb cifs: do not allow changing posix_paths during remount cifs: uncomplicate printing the iocharset parameter cifs: don't create a temp nls in cifs_setup_ipc cifs: simplify handling of cifs_sb/ctx->local_nls cifs: we do not allow changing username/password/unc/... during remount cifs: add initial reconfigure support ...
2020-12-16cifs: Fix some error pointers handling detected by static checkerSamuel Cabrero1-10/+11
* extract_hostname() and extract_sharename() never return NULL, so use IS_ERR() instead of IS_ERR_OR_NULL() in cifs_find_swn_reg(). If any of these functions return an error, then return an error pointer instead of NULL. * Change cifs_find_swn_reg() function to always return a valid pointer or an error pointer, instead of returning NULL if the registration is not found. * Finally update cifs_find_swn_reg() callers to check for -EEXIST instead of NULL. * In cifs_get_swn_reg() the swnreg idr mutex was not unlocked in the error path of cifs_find_swn_reg() call. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Samuel Cabrero <scabrero@suse.de> Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-14cifs: Handle witness client move notificationSamuel Cabrero1-2/+138
This message is sent to tell a client to close its current connection and connect to the specified address. Signed-off-by: Samuel Cabrero <scabrero@suse.de> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-14cifs: Send witness register messages to userspace daemon in echo taskSamuel Cabrero1-0/+15
If the daemon starts after mounting a share, or if it crashes, this provides a mechanism to register again. Signed-off-by: Samuel Cabrero <scabrero@suse.de> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-14cifs: Add witness information to debug data dumpSamuel Cabrero1-0/+35
+ Indicate if witness feature is supported + Indicate if witness is used when dumping tcons + Dumps witness registrations. Example: Witness registrations: Id: 1 Refs: 1 Network name: 'fs.fover.ad'(y) Share name: 'share1'(y) \ Ip address: 192.168.103.200(n) Signed-off-by: Samuel Cabrero <scabrero@suse.de> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-14cifs: Set witness notification handler for messages from userspace daemonSamuel Cabrero1-0/+86
+ Set a handler for the witness notification messages received from the userspace daemon. + Handle the resource state change notification. When the resource becomes unavailable or available set the tcp status to CifsNeedReconnect for all channels. Signed-off-by: Samuel Cabrero <scabrero@suse.de> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-14cifs: Send witness register and unregister commands to userspace daemonSamuel Cabrero1-0/+421
+ Define the generic netlink family commands and message attributes to communicate with the userspace daemon + The register and unregister commands are sent when connecting or disconnecting a tree. The witness registration keeps a pointer to the tcon and has the same lifetime. + Each registration has an id allocated by an IDR. This id is sent to the userspace daemon in the register command, and will be included in the notification messages from the userspace daemon to retrieve from the IDR the matching registration. + The authentication information is bundled in the register message. If kerberos is used the message just carries a flag. Signed-off-by: Samuel Cabrero <scabrero@suse.de> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>