summaryrefslogtreecommitdiff
path: root/fs/smb/client/connect.c
AgeCommit message (Collapse)AuthorFilesLines
2023-12-06cifs: reconnect worker should take reference on server struct unconditionallyShyam Prasad N1-4/+4
Reconnect worker currently assumes that the server struct is alive and only takes reference on the server if it needs to call smb2_reconnect. With the new ability to disable channels based on whether the server has multichannel disabled, this becomes a problem when we need to disable established channels. While disabling the channels and deallocating the server, there could be reconnect work that could not be cancelled (because it started). This change forces the reconnect worker to unconditionally take a reference on the server when it runs. Also, this change now allows smb2_reconnect to know if it was called by the reconnect worker. Based on this, the cifs_put_tcp_session can decide whether it can cancel the reconnect work synchronously or not. Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-12-06Revert "cifs: reconnect work should have reference on server struct"Shyam Prasad N1-21/+6
This reverts commit 19a4b9d6c372cab6a3b2c9a061a236136fe95274. This earlier commit was making an assumption that each mod_delayed_work called for the reconnect work would result in smb2_reconnect_server being called twice. This assumption turns out to be untrue. So reverting this change for now. I will submit a follow-up patch to fix the actual problem in a different way. Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-11-14cifs: fix leak of iface for primary channelShyam Prasad N1-0/+6
My last change in this area introduced a change which accounted for primary channel in the interface ref count. However, it did not reduce this ref count on deallocation of the primary channel. i.e. during umount. Fixing this leak here, by dropping this ref count for primary channel while freeing up the session. Fixes: fa1d0508bdd4 ("cifs: account for primary channel in the interface list") Cc: stable@vger.kernel.org Reported-by: Paulo Alcantara <pc@manguebit.com> Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-11-10cifs: handle when server stops supporting multichannelShyam Prasad N1-0/+10
When a server stops supporting multichannel, we will keep attempting reconnects to the secondary channels today. Avoid this by freeing extra channels when negotiate returns no multichannel support. Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-11-10cifs: handle when server starts supporting multichannelShyam Prasad N1-0/+3
When the user mounts with multichannel option, but the server does not support it, there can be a time in future where it can be supported. With this change, such a case is handled. Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
2023-11-09cifs: reconnect work should have reference on server structShyam Prasad N1-6/+21
The delayed work for reconnect takes server struct as a parameter. But it does so without holding a ref to it. Normally, this may not show a problem as the reconnect work is only cancelled on umount. However, since we now plan to support scaling down of channels, and the scale down can happen from reconnect work itself, we need to fix it. This change takes a reference on the server struct before it is passed to the delayed work. And drops the reference in the delayed work itself. Or if the delayed work is successfully cancelled, by the process that cancels it. Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-11-09cifs: do not pass cifs_sb when trying to add channelsShyam Prasad N1-1/+1
The only reason why cifs_sb gets passed today to cifs_try_adding_channels is to pass the local_nls field for the new channels and binding session. However, the ses struct already has local_nls field that is setup during the first cifs_setup_session. So there is no need to pass cifs_sb. This change removes cifs_sb from the arg list for this and the functions that it calls and uses ses->local_nls instead. Cc: stable@vger.kernel.org Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Reviewed-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-11-09cifs: handle cases where a channel is closedShyam Prasad N1-1/+5
So far, SMB multichannel could only scale up, but not scale down the number of channels. In this series of patch, we now allow the client to deal with the case of multichannel disabled on the server when the share is mounted. With that change, we now need the ability to scale down the channels. This change allows the client to deal with cases of missing channels more gracefully. Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-11-02cifs: force interface update before a fresh session setupShyam Prasad N1-1/+5
During a session reconnect, it is possible that the server moved to another physical server (happens in case of Azure files). So at this time, force a query of server interfaces again (in case of multichannel session), such that the secondary channels connect to the right IP addresses (possibly updated now). Cc: stable@vger.kernel.org Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-11-02cifs: reconnect helper should set reconnect for the right channelShyam Prasad N1-4/+5
We introduced a helper function to be used by non-cifsd threads to mark the connection for reconnect. For multichannel, when only a particular channel needs to be reconnected, this had a bug. This change fixes that by marking that particular channel for reconnect. Fixes: dca65818c80c ("cifs: use a different reconnect helper for non-cifsd threads") Cc: stable@vger.kernel.org Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Reviewed-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-11-02smb: client: remove extra @chan_count check in __cifs_put_smb_ses()Paulo Alcantara1-14/+9
If @ses->chan_count <= 1, then for-loop body will not be executed so no need to check it twice. Reviewed-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-10-31cifs: add xid to query server interface callShyam Prasad N1-1/+5
We were passing 0 as the xid for the call to query server interfaces. This is not great for debugging. This change adds a real xid. Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Reviewed-by: Bharath SM <bharathsm@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-10-04smb: client: do not start laundromat thread on nohandlecachePaulo Alcantara1-8/+8
Honor 'nohandlecache' mount option by not starting laundromat thread even when SMB server supports directory leases. Do not waste system resources by having laundromat thread running with no directory caching at all. Fixes: 2da338ff752a ("smb3: do not start laundromat thread when dir leases disabled") Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-10-04smb: use kernel_connect() and kernel_bind()Jordan Rife1-5/+5
Recent changes to kernel_connect() and kernel_bind() ensure that callers are insulated from changes to the address parameter made by BPF SOCK_ADDR hooks. This patch wraps direct calls to ops->connect() and ops->bind() with kernel_connect() and kernel_bind() to ensure that SMB mounts do not see their mount address overwritten in such cases. Link: https://lore.kernel.org/netdev/9944248dba1bce861375fcce9de663934d933ba9.camel@redhat.com/ Cc: <stable@vger.kernel.org> # 6.0+ Signed-off-by: Jordan Rife <jrife@google.com> Acked-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-09-19smb3: do not start laundromat thread when dir leasesSteve French1-2/+6
disabled When no directory lease support, or for IPC shares where directories can not be opened, do not start an unneeded laundromat thread for that mount (it wastes resources). Fixes: d14de8067e3f ("cifs: Add a laundromat thread for cached directories") Reviewed-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Acked-by: Tom Talpey <tom@talpey.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-09-07smb3: allow controlling maximum number of cached directoriesSteve French1-0/+1
Allow adjusting the maximum number of cached directories per share (defaults to 16) via mount parm "max_cached_dirs" Signed-off-by: Steve French <stfrench@microsoft.com>
2023-08-30SMB3: rename macro CIFS_SERVER_IS_CHAN to avoid confusionSteve French1-6/+6
Since older dialects such as CIFS do not support multichannel the macro CIFS_SERVER_IS_CHAN can be confusing (it requires SMB 3 or later) so shorten its name to "SERVER_IS_CHAN" Suggested-by: Tom Talpey <tom@talpey.com> Acked-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-08-24[SMB3] send channel sequence number in SMB3 requests after reconnectsSteve French1-0/+1
The ChannelSequence field in the SMB3 header is supposed to be increased after reconnect to allow the server to distinguish requests from before and after the reconnect. We had always been setting it to zero. There are cases where incrementing ChannelSequence on requests after network reconnects can reduce the chance of data corruptions. See MS-SMB2 3.2.4.1 and 3.2.7.1 Signed-off-by: Steve French <stfrench@microsoft.com> Cc: stable@vger.kernel.org # 5.16+
2023-08-20smb: client: reduce stack usage in cifs_demultiplex_thread()Paulo Alcantara1-2/+2
Clang warns about exceeded stack frame size fs/smb/client/connect.c:1109:1: warning: stack frame size (1048) exceeds limit (1024) in 'cifs_demultiplex_thread' [-Wframe-larger-than] It turns out that clean_demultiplex_info() got inlined into cifs_demultiplex_thread(), so mark it as noinline_for_stack to save some stack space. Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-08-20smb: client: introduce DFS_CACHE_TGT_LIST()Paulo Alcantara1-2/+2
Add new helper which declares and initialises target list of a DFS referral rather having to do both separately. No functional changes. Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-07-25cifs: fix charset issue in reconnectionWinston Wen1-0/+5
We need to specify charset, like "iocharset=utf-8", in mount options for Chinese path if the nls_default don't support it, such as iso8859-1, the default value for CONFIG_NLS_DEFAULT. But now in reconnection the nls_default is used, instead of the one we specified and used in mount, and this can lead to mount failure. Signed-off-by: Winston Wen <wentao@uniontech.com> Reviewed-by: Paulo Alcantara <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-07-14cifs: fix mid leak during reconnection after timeout thresholdShyam Prasad N1-4/+15
When the number of responses with status of STATUS_IO_TIMEOUT exceeds a specified threshold (NUM_STATUS_IO_TIMEOUT), we reconnect the connection. But we do not return the mid, or the credits returned for the mid, or reduce the number of in-flight requests. This bug could result in the server->in_flight count to go bad, and also cause a leak in the mids. This change moves the check to a few lines below where the response is decrypted, even of the response is read from the transform header. This way, the code for returning the mids can be reused. Also, the cifs_reconnect was reconnecting just the transport connection before. In case of multi-channel, this may not be what we want to do after several timeouts. Changed that to reconnect the session and the tree too. Also renamed NUM_STATUS_IO_TIMEOUT to a more appropriate name MAX_STATUS_IO_TIMEOUT. Fixes: 8e670f77c4a5 ("Handle STATUS_IO_TIMEOUT gracefully") Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-07-14cifs: is_network_name_deleted should return a boolShyam Prasad N1-3/+8
Currently, is_network_name_deleted and it's implementations do not return anything if the network name did get deleted. So the function doesn't fully achieve what it advertizes. Changed the function to return a bool instead. It will now return true if the error returned is STATUS_NETWORK_NAME_DELETED and the share (tree id) was found to be connected. It returns false otherwise. Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Acked-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-07-01cifs: fix session state transition to avoid use-after-free issueWinston Wen1-3/+4
We switch session state to SES_EXITING without cifs_tcp_ses_lock now, it may lead to potential use-after-free issue. Consider the following execution processes: Thread 1: __cifs_put_smb_ses() spin_lock(&cifs_tcp_ses_lock) if (--ses->ses_count > 0) spin_unlock(&cifs_tcp_ses_lock) return spin_unlock(&cifs_tcp_ses_lock) ---> **GAP** spin_lock(&ses->ses_lock) if (ses->ses_status == SES_GOOD) ses->ses_status = SES_EXITING spin_unlock(&ses->ses_lock) Thread 2: cifs_find_smb_ses() spin_lock(&cifs_tcp_ses_lock) list_for_each_entry(ses, ...) spin_lock(&ses->ses_lock) if (ses->ses_status == SES_EXITING) spin_unlock(&ses->ses_lock) continue ... spin_unlock(&ses->ses_lock) if (ret) cifs_smb_ses_inc_refcount(ret) spin_unlock(&cifs_tcp_ses_lock) If thread 1 is preempted in the gap and thread 2 start executing, thread 2 will get the session, and soon thread 1 will switch the session state to SES_EXITING and start releasing it, even though thread 1 had increased the session's refcount and still uses it. So switch session state under cifs_tcp_ses_lock to eliminate this gap. Signed-off-by: Winston Wen <wentao@uniontech.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-06-28smb: client: fix shared DFS root mounts with different prefixesPaulo Alcantara1-30/+40
When having two DFS root mounts that are connected to same namespace, same mount options but different prefix paths, we can't really use the shared @server->origin_fullpath when chasing DFS links in them. Move the origin_fullpath field to cifs_tcon structure so when having shared DFS root mounts with different prefix paths, and we need to chase any DFS links, dfs_get_automount_devname() will pick up the correct full path out of the @tcon that will be used for the new mount. Before patch mount.cifs //dom/dfs/dir /mnt/1 -o ... mount.cifs //dom/dfs /mnt/2 -o ... # shared server, ses, tcon # server: origin_fullpath=//dom/dfs/dir # @server->origin_fullpath + '/dir/link1' $ ls /mnt/2/dir/link1 ls: cannot open directory '/mnt/2/dir/link1': No such file or directory After patch mount.cifs //dom/dfs/dir /mnt/1 -o ... mount.cifs //dom/dfs /mnt/2 -o ... # shared server & ses # tcon_1: origin_fullpath=//dom/dfs/dir # tcon_2: origin_fullpath=//dom/dfs # @tcon_2->origin_fullpath + '/dir/link1' $ ls /mnt/2/dir/link1 dir0 dir1 dir10 dir3 dir5 dir6 dir7 dir9 target2_file.txt tsub Fixes: 8e3554150d6c ("cifs: fix sharing of DFS connections") Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-06-20smb: client: fix warning in generic_ip_connect()Paulo Alcantara1-8/+9
This fixes the following warning reported by kernel test robot fs/smb/client/connect.c:2974 generic_ip_connect() error: we previously assumed 'socket' could be null (see line 2962) Link: https://lore.kernel.org/all/202306170124.CtQqzf0I-lkp@intel.com/ Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-06-19smb: client: fix warning in cifs_match_super()Paulo Alcantara1-2/+3
Fix potential dereference of ERR_PTR @tlink as reported by kernel test robot fs/smb/client/connect.c:2775 cifs_match_super() error: 'tlink' dereferencing possible ERR_PTR() Link: https://lore.kernel.org/all/202306170124.CtQqzf0I-lkp@intel.com/ Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-06-11cifs: fix sockaddr comparison in iface_cmpShyam Prasad N1-0/+50
iface_cmp used to simply do a memcmp of the two provided struct sockaddrs. The comparison needs to do more based on the address family. Similar logic was already present in cifs_match_ipaddr. Doing something similar now. Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-06-11cifs: fix status checks in cifs_tree_connectShyam Prasad N1-4/+5
The ordering of status checks at the beginning of cifs_tree_connect is wrong. As a result, a tcon which is good may stay marked as needing reconnect infinitely. Fixes: 2f0e4f034220 ("cifs: check only tcon status on tcon related functions") Cc: stable@vger.kernel.org # 6.3 Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-05-24smb: move client and server files to common directory fs/smbSteve French1-0/+4118
Move CIFS/SMB3 related client and server files (cifs.ko and ksmbd.ko and helper modules) to new fs/smb subdirectory: fs/cifs --> fs/smb/client fs/ksmbd --> fs/smb/server fs/smbfs_common --> fs/smb/common Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>