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path: root/fs/cifs/cifsglob.h
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2020-12-18SMB3: Add support for getting and setting SACLsBoris Protopopov
Add SYSTEM_SECURITY access flag and use with smb2 when opening files for getting/setting SACLs. Add "system.cifs_ntsd_full" extended attribute to allow user-space access to the functionality. Avoid multiple server calls when setting owner, DACL, and SACL. Signed-off-by: Boris Protopopov <pboris@amazon.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-14cifs: Handle witness client move notificationSamuel Cabrero
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: add witness mount option and data structsSamuel Cabrero
Add 'witness' mount option to register for witness notifications. Signed-off-by: Samuel Cabrero <scabrero@suse.de> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-13cifs: rename smb_vol as smb3_fs_context and move it to fs_context.hRonnie Sahlberg
Harmonize and change all such variables to 'ctx', where possible. No changes to actual logic. Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-10-23smb3: add support for stat of WSL reparse points for special file typesSteve French
This is needed so when mounting to Windows we do not misinterpret various special files created by Linux (WSL) as symlinks. An earlier patch addressed readdir. This patch fixes stat (getattr). With this patch:   File: /mnt1/char   Size: 0          Blocks: 0          IO Block: 16384  character special file Device: 34h/52d Inode: 844424930132069  Links: 1     Device type: 0,0 Access: (0755/crwxr-xr-x)  Uid: (    0/    root)   Gid: (    0/    root) Access: 2020-10-21 17:46:51.839458900 -0500 Modify: 2020-10-21 17:46:51.839458900 -0500 Change: 2020-10-21 18:30:39.797358800 -0500  Birth: -   File: /mnt1/fifo   Size: 0          Blocks: 0          IO Block: 16384  fifo Device: 34h/52d Inode: 1125899906842722  Links: 1 Access: (0755/prwxr-xr-x)  Uid: (    0/    root)   Gid: (    0/    root) Access: 2020-10-21 16:21:37.259249700 -0500 Modify: 2020-10-21 16:21:37.259249700 -0500 Change: 2020-10-21 18:30:39.797358800 -0500  Birth: -   File: /mnt1/block   Size: 0          Blocks: 0          IO Block: 16384  block special file Device: 34h/52d Inode: 844424930132068  Links: 1     Device type: 0,0 Access: (0755/brwxr-xr-x)  Uid: (    0/    root)   Gid: (    0/    root) Access: 2020-10-21 17:10:47.913103200 -0500 Modify: 2020-10-21 17:10:47.913103200 -0500 Change: 2020-10-21 18:30:39.796725500 -0500  Birth: - without the patch all show up incorrectly as symlinks with annoying "operation not supported error also returned"   File: /mnt1/charstat: cannot read symbolic link '/mnt1/char': Operation not supported   Size: 0          Blocks: 0          IO Block: 16384  symbolic link Device: 34h/52d Inode: 844424930132069  Links: 1 Access: (0000/l---------)  Uid: (    0/    root)   Gid: (    0/    root) Access: 2020-10-21 17:46:51.839458900 -0500 Modify: 2020-10-21 17:46:51.839458900 -0500 Change: 2020-10-21 18:30:39.797358800 -0500  Birth: -   File: /mnt1/fifostat: cannot read symbolic link '/mnt1/fifo': Operation not supported   Size: 0          Blocks: 0          IO Block: 16384  symbolic link Device: 34h/52d Inode: 1125899906842722  Links: 1 Access: (0000/l---------)  Uid: (    0/    root)   Gid: (    0/    root) Access: 2020-10-21 16:21:37.259249700 -0500 Modify: 2020-10-21 16:21:37.259249700 -0500 Change: 2020-10-21 18:30:39.797358800 -0500  Birth: -   File: /mnt1/blockstat: cannot read symbolic link '/mnt1/block': Operation not supported   Size: 0          Blocks: 0          IO Block: 16384  symbolic link Device: 34h/52d Inode: 844424930132068  Links: 1 Access: (0000/l---------)  Uid: (    0/    root)   Gid: (    0/    root) Access: 2020-10-21 17:10:47.913103200 -0500 Modify: 2020-10-21 17:10:47.913103200 -0500 Change: 2020-10-21 18:30:39.796725500 -0500 Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
2020-10-22cifs: move smb version mount options into fs_context.cRonnie Sahlberg
This and related patches which move mount related code to fs_context.c has the advantage of shriking the code in fs/cifs/connect.c (which had the second most lines of code of any of the files in cifs.ko and was getting harder to read due to its size) and will also make it easier to switch over to the new mount API in the future. Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-10-15smb3.1.1: add new module load parm enable_gcm_256Steve French
Add new module load parameter enable_gcm_256. If set, then add AES-256-GCM (strongest encryption type) to the list of encryption types requested. Put it in the list as the second choice (since AES-128-GCM is faster and much more broadly supported by SMB3 servers). To make this stronger encryption type, GCM-256, required (the first and only choice, you would use module parameter "require_gcm_256." Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-10-15smb3.1.1: add new module load parm require_gcm_256Steve French
Add new module load parameter require_gcm_256. If set, then only request AES-256-GCM (strongest encryption type). Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-10-15Handle STATUS_IO_TIMEOUT gracefullyRohith Surabattula
Currently STATUS_IO_TIMEOUT is not treated as retriable error. It is currently mapped to ETIMEDOUT and returned to userspace for most system calls. STATUS_IO_TIMEOUT is returned by server in case of unavailability or throttling errors. This patch will map the STATUS_IO_TIMEOUT to EAGAIN, so that it can be retried. Also, added a check to drop the connection to not overload the server in case of ongoing unavailability. Signed-off-by: Rohith Surabattula <rohiths@microsoft.com> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-08-28cifs: fix check of tcon dfs in smb1Paulo Alcantara
For SMB1, the DFS flag should be checked against tcon->Flags rather than tcon->share_flags. While at it, add an is_tcon_dfs() helper to check for DFS capability in a more generic way. Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Shyam Prasad N <nspmangalore@gmail.com>
2020-08-06Merge tag '5.9-rc-smb3-fixes-part1' of git://git.samba.org/sfrench/cifs-2.6Linus Torvalds
Pull cifs updates from Steve French: "16 cifs/smb3 fixes, about half DFS related, two fixes for stable. Still working on and testing an additional set of fixes (including updates to mount, and some fallocate scenario improvements) for later in the merge window" * tag '5.9-rc-smb3-fixes-part1' of git://git.samba.org/sfrench/cifs-2.6: cifs: document and cleanup dfs mount cifs: only update prefix path of DFS links in cifs_tree_connect() cifs: fix double free error on share and prefix cifs: handle RESP_GET_DFS_REFERRAL.PathConsumed in reconnect cifs: handle empty list of targets in cifs_reconnect() cifs: rename reconn_inval_dfs_target() cifs: reduce number of referral requests in DFS link lookups cifs: merge __{cifs,smb2}_reconnect[_tcon]() into cifs_tree_connect() cifs: convert to use be32_add_cpu() cifs: delete duplicated words in header files cifs: Remove the superfluous break cifs: smb1: Try failing back to SetFileInfo if SetPathInfo fails cifs`: handle ERRBaduid for SMB1 cifs: remove unused variable 'server' smb3: warn on confusing error scenario with sec=krb5 cifs: Fix leak when handling lease break for cached root fid
2020-08-02cifs: delete duplicated words in header filesRandy Dunlap
Drop repeated words in multiple comments. (be, use, the, See) Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Steve French <sfrench@samba.org> Cc: linux-cifs@vger.kernel.org Cc: samba-technical@lists.samba.org Signed-off-by: Steve French <stfrench@microsoft.com>
2020-07-05Replace HTTP links with HTTPS ones: CIFSAlexander A. Klimov
Rationale: Reduces attack surface on kernel devs opening the links for MITM as HTTPS traffic is much harder to manipulate. Deterministic algorithm: For each file: If not .svg: For each line: If doesn't contain `\bxmlns\b`: For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`: If both the HTTP and HTTPS versions return 200 OK and serve the same content: Replace HTTP with HTTPS. Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Link: https://lore.kernel.org/r/20200627103125.71828-1-grandmaster@al2klimov.de Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-06-08cifs: Add get_security_type_str function to return sec type.Kenneth D'souza
This code is more organized and robust. Signed-off-by: Kenneth D'souza <kdsouza@redhat.com> Signed-off-by: Roberto Bergantinos Corpas <rbergant@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-06-04cifs: multichannel: use pointer for binding channelAurelien Aptel
Add a cifs_chan pointer in struct cifs_ses that points to the channel currently being bound if ses->binding is true. Previously it was always the channel past the established count. This will make reconnecting (and rebinding) a channel easier later on. Signed-off-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-06-04cifs: multichannel: move channel selection above transport layerAurelien Aptel
Move the channel (TCP_Server_Info*) selection from the tranport layer to higher in the call stack so that: - credit handling is done with the server that will actually be used to send. * ->wait_mtu_credit * ->set_credits / set_credits * ->add_credits / add_credits * add_credits_and_wake_if - potential reconnection (smb2_reconnect) done when initializing a request is checked and done with the server that will actually be used to send. To do this: - remove the cifs_pick_channel() call out of compound_send_recv() - select channel and pass it down by adding a cifs_pick_channel(ses) call in: - smb311_posix_mkdir - SMB2_open - SMB2_ioctl - __SMB2_close - query_info - SMB2_change_notify - SMB2_flush - smb2_async_readv (if none provided in context param) - SMB2_read (if none provided in context param) - smb2_async_writev (if none provided in context param) - SMB2_write (if none provided in context param) - SMB2_query_directory - send_set_info - SMB2_oplock_break - SMB311_posix_qfs_info - SMB2_QFS_info - SMB2_QFS_attr - smb2_lockv - SMB2_lease_break - smb2_compound_op - smb2_set_ea - smb2_ioctl_query_info - smb2_query_dir_first - smb2_query_info_comound - smb2_query_symlink - cifs_writepages - cifs_write_from_iter - cifs_send_async_read - cifs_read - cifs_readpages - add TCP_Server_Info *server param argument to: - cifs_send_recv - compound_send_recv - SMB2_open_init - SMB2_query_info_init - SMB2_set_info_init - SMB2_close_init - SMB2_ioctl_init - smb2_iotcl_req_init - SMB2_query_directory_init - SMB2_notify_init - SMB2_flush_init - build_qfs_info_req - smb2_hdr_assemble - smb2_reconnect - fill_small_buf - smb2_plain_req_init - __smb2_plain_req_init The read/write codepath is different than the rest as it is using pages, io iterators and async calls. To deal with those we add a server pointer in the cifs_writedata/cifs_readdata/cifs_io_parms context struct and set it in: - cifs_writepages (wdata) - cifs_write_from_iter (wdata) - cifs_readpages (rdata) - cifs_send_async_read (rdata) The [rw]data->server pointer is eventually copied to cifs_io_parms->server to pass it down to SMB2_read/SMB2_write. If SMB2_read/SMB2_write is called from a different place that doesn't set the server field it will pick a channel. Some places do not pick a channel and just use ses->server or cifs_ses_server(ses). All cifs_ses_server(ses) calls are in codepaths involving negprot/sess.setup. - SMB2_negotiate (binding channel) - SMB2_sess_alloc_buffer (binding channel) - SMB2_echo (uses provided one) - SMB2_logoff (uses master) - SMB2_tdis (uses master) (list not exhaustive) Signed-off-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-06-01smb3: Add new parm "nodelete"Steve French
In order to handle workloads where it is important to make sure that a buggy app did not delete content on the drive, the new mount option "nodelete" allows standard permission checks on the server to work, but prevents on the client any attempts to unlink a file or delete a directory on that mount point. This can be helpful when running a little understood app on a network mount that contains important content that should not be deleted. Signed-off-by: Steve French <stfrench@microsoft.com> CC: Stable <stable@vger.kernel.org> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2020-04-21cifs: minor update to comments around the cifs_tcp_ses_lock mutexSteve French
Update comment to note that it protects server->dstaddr Signed-off-by: Steve French <stfrench@microsoft.com>
2020-04-10smb3: enable swap on SMB3 mountsSteve French
Add experimental support for allowing a swap file to be on an SMB3 mount. There are use cases where swapping over a secure network filesystem is preferable. In some cases there are no local block devices large enough, and network block devices can be hard to setup and secure. And in some cases there are no local block devices at all (e.g. with the recent addition of remote boot over SMB3 mounts). There are various enhancements that can be added later e.g.: - doing a mandatory byte range lock over the swapfile (until the Linux VFS is modified to notify the file system that an open is for a swapfile, when the file can be opened "DENY_ALL" to prevent others from opening it). - pinning more buffers in the underlying transport to minimize memory allocations in the TCP stack under the fs - documenting how to create ACLs (on the server) to secure the swapfile (or adding additional tools to cifs-utils to make it easier) Signed-off-by: Steve French <stfrench@microsoft.com> Acked-by: Pavel Shilovsky <pshilov@microsoft.com> Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
2020-04-07cifs: Allocate crypto structures on the fly for calculating signatures of ↵Long Li
incoming packets CIFS uses pre-allocated crypto structures to calculate signatures for both incoming and outgoing packets. In this way it doesn't need to allocate crypto structures for every packet, but it requires a lock to prevent concurrent access to crypto structures. Remove the lock by allocating crypto structures on the fly for incoming packets. At the same time, we can still use pre-allocated crypto structures for outgoing packets, as they are already protected by transport lock srv_mutex. Signed-off-by: Long Li <longli@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2020-02-24cifs: fix rename() by ensuring source handle opened with DELETE bitAurelien Aptel
To rename a file in SMB2 we open it with the DELETE access and do a special SetInfo on it. If the handle is missing the DELETE bit the server will fail the SetInfo with STATUS_ACCESS_DENIED. We currently try to reuse any existing opened handle we have with cifs_get_writable_path(). That function looks for handles with WRITE access but doesn't check for DELETE, making rename() fail if it finds a handle to reuse. Simple reproducer below. To select handles with the DELETE bit, this patch adds a flag argument to cifs_get_writable_path() and find_writable_file() and the existing 'bool fsuid_only' argument is converted to a flag. The cifsFileInfo struct only stores the UNIX open mode but not the original SMB access flags. Since the DELETE bit is not mapped in that mode, this patch stores the access mask in cifs_fid on file open, which is accessible from cifsFileInfo. Simple reproducer: #include <stdio.h> #include <stdlib.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <unistd.h> #define E(s) perror(s), exit(1) int main(int argc, char *argv[]) { int fd, ret; if (argc != 3) { fprintf(stderr, "Usage: %s A B\n" "create&open A in write mode, " "rename A to B, close A\n", argv[0]); return 0; } fd = openat(AT_FDCWD, argv[1], O_WRONLY|O_CREAT|O_SYNC, 0666); if (fd == -1) E("openat()"); ret = rename(argv[1], argv[2]); if (ret) E("rename()"); ret = close(fd); if (ret) E("close()"); return ret; } $ gcc -o bugrename bugrename.c $ ./bugrename /mnt/a /mnt/b rename(): Permission denied Fixes: 8de9e86c67ba ("cifs: create a helper to find a writeable handle by path name") CC: Stable <stable@vger.kernel.org> Signed-off-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com> Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
2020-02-06cifs: add SMB3 change notification supportSteve French
A commonly used SMB3 feature is change notification, allowing an app to be notified about changes to a directory. The SMB3 Notify request blocks until the server detects a change to that directory or its contents that matches the completion flags that were passed in and the "watch_tree" flag (which indicates whether subdirectories under this directory should be also included). See MS-SMB2 2.2.35 for additional detail. To use this simply pass in the following structure to ioctl: struct __attribute__((__packed__)) smb3_notify { uint32_t completion_filter; bool watch_tree; } __packed; using CIFS_IOC_NOTIFY 0x4005cf09 or equivalently _IOW(CIFS_IOCTL_MAGIC, 9, struct smb3_notify) SMB3 change notification is supported by all major servers. The ioctl will block until the server detects a change to that directory or its subdirectories (if watch_tree is set). Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Acked-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
2020-02-03SMB3: Backup intent flag missing from some more opsAmir Goldstein
When "backup intent" is requested on the mount (e.g. backupuid or backupgid mount options), the corresponding flag was missing from some of the operations. Change all operations to use the macro cifs_create_options() to set the backup intent flag if needed. Signed-off-by: Amir Goldstein <amir73il@gmail.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>
2019-12-23cifs: Optimize readdir on reparse pointsPaulo Alcantara (SUSE)
When listing a directory with thounsands of files and most of them are reparse points, we simply marked all those dentries for revalidation and then sending additional (compounded) create/getinfo/close requests for each of them. Instead, upon receiving a response from an SMB2_QUERY_DIRECTORY (FileIdFullDirectoryInformation) command, the directory entries that have a file attribute of FILE_ATTRIBUTE_REPARSE_POINT will contain an EaSize field with a reparse tag in it, so we parse it and mark the dentry for revalidation only if it is a DFS or a symlink. Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-12-13CIFS: Close cached root handle only if it has a leasePavel Shilovsky
SMB2_tdis() checks if a root handle is valid in order to decide whether it needs to close the handle or not. However if another thread has reference for the handle, it may end up with putting the reference twice. The extra reference that we want to put during the tree disconnect is the reference that has a directory lease. So, track the fact that we have a directory lease and close the handle only in that case. Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-12-04cifs: Fix lookup of SMB connections on multichannelPaulo Alcantara (SUSE)
With the addition of SMB session channels, we introduced new TCP server pointers that have no sessions or tcons associated with them. In this case, when we started looking for TCP connections, we might end up picking session channel rather than the master connection, hence failing to get either a session or a tcon. In order to fix that, this patch introduces a new "is_channel" field to TCP_Server_Info structure so we can skip session channels during lookup of connections. Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-12-03smb3: query attributes on file closeSteve French
Since timestamps on files on most servers can be updated at close, and since timestamps on our dentries default to one second we can have stale timestamps in some common cases (e.g. open, write, close, stat, wait one second, stat - will show different mtime for the first and second stat). The SMB2/SMB3 protocol allows querying timestamps at close so add the code to request timestamp and attr information (which is cheap for the server to provide) to be returned when a file is closed (it is not needed for the many paths that call SMB2_close that are from compounded query infos and close nor is it needed for some of the cases where a directory close immediately follows a directory open. Signed-off-by: Steve French <stfrench@microsoft.com> Acked-by: Ronnie Sahlberg <lsahlber@redhat.com> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2019-11-25smb3: dump in_send and num_waiters stats counters by defaultSteve French
Number of requests in_send and the number of waiters on sendRecv are useful counters in various cases, move them from CONFIG_CIFS_STATS2 to be on by default especially with multichannel Signed-off-by: Steve French <stfrench@microsoft.com> Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
2019-11-25CIFS: Properly process SMB3 lease breaksPavel Shilovsky
Currenly we doesn't assume that a server may break a lease from RWH to RW which causes us setting a wrong lease state on a file and thus mistakenly flushing data and byte-range locks and purging cached data on the client. This leads to performance degradation because subsequent IOs go directly to the server. Fix this by propagating new lease state and epoch values to the oplock break handler through cifsFileInfo structure and removing the use of cifsInodeInfo flags for that. It allows to avoid some races of several lease/oplock breaks using those flags in parallel. Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-11-25cifs: move cifsFileInfo_put logic into a work-queueRonnie Sahlberg
This patch moves the final part of the cifsFileInfo_put() logic where we need a write lock on lock_sem to be processed in a separate thread that holds no other locks. This is to prevent deadlocks like the one below: > there are 6 processes looping to while trying to down_write > cinode->lock_sem, 5 of them from _cifsFileInfo_put, and one from > cifs_new_fileinfo > > and there are 5 other processes which are blocked, several of them > waiting on either PG_writeback or PG_locked (which are both set), all > for the same page of the file > > 2 inode_lock() (inode->i_rwsem) for the file > 1 wait_on_page_writeback() for the page > 1 down_read(inode->i_rwsem) for the inode of the directory > 1 inode_lock()(inode->i_rwsem) for the inode of the directory > 1 __lock_page > > > so processes are blocked waiting on: > page flags PG_locked and PG_writeback for one specific page > inode->i_rwsem for the directory > inode->i_rwsem for the file > cifsInodeInflock_sem > > > > here are the more gory details (let me know if I need to provide > anything more/better): > > [0 00:48:22.765] [UN] PID: 8863 TASK: ffff8c691547c5c0 CPU: 3 > COMMAND: "reopen_file" > #0 [ffff9965007e3ba8] __schedule at ffffffff9b6e6095 > #1 [ffff9965007e3c38] schedule at ffffffff9b6e64df > #2 [ffff9965007e3c48] rwsem_down_write_slowpath at ffffffff9af283d7 > #3 [ffff9965007e3cb8] legitimize_path at ffffffff9b0f975d > #4 [ffff9965007e3d08] path_openat at ffffffff9b0fe55d > #5 [ffff9965007e3dd8] do_filp_open at ffffffff9b100a33 > #6 [ffff9965007e3ee0] do_sys_open at ffffffff9b0eb2d6 > #7 [ffff9965007e3f38] do_syscall_64 at ffffffff9ae04315 > * (I think legitimize_path is bogus) > > in path_openat > } else { > const char *s = path_init(nd, flags); > while (!(error = link_path_walk(s, nd)) && > (error = do_last(nd, file, op)) > 0) { <<<< > > do_last: > if (open_flag & O_CREAT) > inode_lock(dir->d_inode); <<<< > else > so it's trying to take inode->i_rwsem for the directory > > DENTRY INODE SUPERBLK TYPE PATH > ffff8c68bb8e79c0 ffff8c691158ef20 ffff8c6915bf9000 DIR /mnt/vm1_smb/ > inode.i_rwsem is ffff8c691158efc0 > > <struct rw_semaphore 0xffff8c691158efc0>: > owner: <struct task_struct 0xffff8c6914275d00> (UN - 8856 - > reopen_file), counter: 0x0000000000000003 > waitlist: 2 > 0xffff9965007e3c90 8863 reopen_file UN 0 1:29:22.926 > RWSEM_WAITING_FOR_WRITE > 0xffff996500393e00 9802 ls UN 0 1:17:26.700 > RWSEM_WAITING_FOR_READ > > > the owner of the inode.i_rwsem of the directory is: > > [0 00:00:00.109] [UN] PID: 8856 TASK: ffff8c6914275d00 CPU: 3 > COMMAND: "reopen_file" > #0 [ffff99650065b828] __schedule at ffffffff9b6e6095 > #1 [ffff99650065b8b8] schedule at ffffffff9b6e64df > #2 [ffff99650065b8c8] schedule_timeout at ffffffff9b6e9f89 > #3 [ffff99650065b940] msleep at ffffffff9af573a9 > #4 [ffff99650065b948] _cifsFileInfo_put.cold.63 at ffffffffc0a42dd6 [cifs] > #5 [ffff99650065ba38] cifs_writepage_locked at ffffffffc0a0b8f3 [cifs] > #6 [ffff99650065bab0] cifs_launder_page at ffffffffc0a0bb72 [cifs] > #7 [ffff99650065bb30] invalidate_inode_pages2_range at ffffffff9b04d4bd > #8 [ffff99650065bcb8] cifs_invalidate_mapping at ffffffffc0a11339 [cifs] > #9 [ffff99650065bcd0] cifs_revalidate_mapping at ffffffffc0a1139a [cifs] > #10 [ffff99650065bcf0] cifs_d_revalidate at ffffffffc0a014f6 [cifs] > #11 [ffff99650065bd08] path_openat at ffffffff9b0fe7f7 > #12 [ffff99650065bdd8] do_filp_open at ffffffff9b100a33 > #13 [ffff99650065bee0] do_sys_open at ffffffff9b0eb2d6 > #14 [ffff99650065bf38] do_syscall_64 at ffffffff9ae04315 > > cifs_launder_page is for page 0xffffd1e2c07d2480 > > crash> page.index,mapping,flags 0xffffd1e2c07d2480 > index = 0x8 > mapping = 0xffff8c68f3cd0db0 > flags = 0xfffffc0008095 > > PAGE-FLAG BIT VALUE > PG_locked 0 0000001 > PG_uptodate 2 0000004 > PG_lru 4 0000010 > PG_waiters 7 0000080 > PG_writeback 15 0008000 > > > inode is ffff8c68f3cd0c40 > inode.i_rwsem is ffff8c68f3cd0ce0 > DENTRY INODE SUPERBLK TYPE PATH > ffff8c68a1f1b480 ffff8c68f3cd0c40 ffff8c6915bf9000 REG > /mnt/vm1_smb/testfile.8853 > > > this process holds the inode->i_rwsem for the parent directory, is > laundering a page attached to the inode of the file it's opening, and in > _cifsFileInfo_put is trying to down_write the cifsInodeInflock_sem > for the file itself. > > > <struct rw_semaphore 0xffff8c68f3cd0ce0>: > owner: <struct task_struct 0xffff8c6914272e80> (UN - 8854 - > reopen_file), counter: 0x0000000000000003 > waitlist: 1 > 0xffff9965005dfd80 8855 reopen_file UN 0 1:29:22.912 > RWSEM_WAITING_FOR_WRITE > > this is the inode.i_rwsem for the file > > the owner: > > [0 00:48:22.739] [UN] PID: 8854 TASK: ffff8c6914272e80 CPU: 2 > COMMAND: "reopen_file" > #0 [ffff99650054fb38] __schedule at ffffffff9b6e6095 > #1 [ffff99650054fbc8] schedule at ffffffff9b6e64df > #2 [ffff99650054fbd8] io_schedule at ffffffff9b6e68e2 > #3 [ffff99650054fbe8] __lock_page at ffffffff9b03c56f > #4 [ffff99650054fc80] pagecache_get_page at ffffffff9b03dcdf > #5 [ffff99650054fcc0] grab_cache_page_write_begin at ffffffff9b03ef4c > #6 [ffff99650054fcd0] cifs_write_begin at ffffffffc0a064ec [cifs] > #7 [ffff99650054fd30] generic_perform_write at ffffffff9b03bba4 > #8 [ffff99650054fda8] __generic_file_write_iter at ffffffff9b04060a > #9 [ffff99650054fdf0] cifs_strict_writev.cold.70 at ffffffffc0a4469b [cifs] > #10 [ffff99650054fe48] new_sync_write at ffffffff9b0ec1dd > #11 [ffff99650054fed0] vfs_write at ffffffff9b0eed35 > #12 [ffff99650054ff00] ksys_write at ffffffff9b0eefd9 > #13 [ffff99650054ff38] do_syscall_64 at ffffffff9ae04315 > > the process holds the inode->i_rwsem for the file to which it's writing, > and is trying to __lock_page for the same page as in the other processes > > > the other tasks: > [0 00:00:00.028] [UN] PID: 8859 TASK: ffff8c6915479740 CPU: 2 > COMMAND: "reopen_file" > #0 [ffff9965007b39d8] __schedule at ffffffff9b6e6095 > #1 [ffff9965007b3a68] schedule at ffffffff9b6e64df > #2 [ffff9965007b3a78] schedule_timeout at ffffffff9b6e9f89 > #3 [ffff9965007b3af0] msleep at ffffffff9af573a9 > #4 [ffff9965007b3af8] cifs_new_fileinfo.cold.61 at ffffffffc0a42a07 [cifs] > #5 [ffff9965007b3b78] cifs_open at ffffffffc0a0709d [cifs] > #6 [ffff9965007b3cd8] do_dentry_open at ffffffff9b0e9b7a > #7 [ffff9965007b3d08] path_openat at ffffffff9b0fe34f > #8 [ffff9965007b3dd8] do_filp_open at ffffffff9b100a33 > #9 [ffff9965007b3ee0] do_sys_open at ffffffff9b0eb2d6 > #10 [ffff9965007b3f38] do_syscall_64 at ffffffff9ae04315 > > this is opening the file, and is trying to down_write cinode->lock_sem > > > [0 00:00:00.041] [UN] PID: 8860 TASK: ffff8c691547ae80 CPU: 2 > COMMAND: "reopen_file" > [0 00:00:00.057] [UN] PID: 8861 TASK: ffff8c6915478000 CPU: 3 > COMMAND: "reopen_file" > [0 00:00:00.059] [UN] PID: 8858 TASK: ffff8c6914271740 CPU: 2 > COMMAND: "reopen_file" > [0 00:00:00.109] [UN] PID: 8862 TASK: ffff8c691547dd00 CPU: 6 > COMMAND: "reopen_file" > #0 [ffff9965007c3c78] __schedule at ffffffff9b6e6095 > #1 [ffff9965007c3d08] schedule at ffffffff9b6e64df > #2 [ffff9965007c3d18] schedule_timeout at ffffffff9b6e9f89 > #3 [ffff9965007c3d90] msleep at ffffffff9af573a9 > #4 [ffff9965007c3d98] _cifsFileInfo_put.cold.63 at ffffffffc0a42dd6 [cifs] > #5 [ffff9965007c3e88] cifs_close at ffffffffc0a07aaf [cifs] > #6 [ffff9965007c3ea0] __fput at ffffffff9b0efa6e > #7 [ffff9965007c3ee8] task_work_run at ffffffff9aef1614 > #8 [ffff9965007c3f20] exit_to_usermode_loop at ffffffff9ae03d6f > #9 [ffff9965007c3f38] do_syscall_64 at ffffffff9ae0444c > > closing the file, and trying to down_write cifsi->lock_sem > > > [0 00:48:22.839] [UN] PID: 8857 TASK: ffff8c6914270000 CPU: 7 > COMMAND: "reopen_file" > #0 [ffff9965006a7cc8] __schedule at ffffffff9b6e6095 > #1 [ffff9965006a7d58] schedule at ffffffff9b6e64df > #2 [ffff9965006a7d68] io_schedule at ffffffff9b6e68e2 > #3 [ffff9965006a7d78] wait_on_page_bit at ffffffff9b03cac6 > #4 [ffff9965006a7e10] __filemap_fdatawait_range at ffffffff9b03b028 > #5 [ffff9965006a7ed8] filemap_write_and_wait at ffffffff9b040165 > #6 [ffff9965006a7ef0] cifs_flush at ffffffffc0a0c2fa [cifs] > #7 [ffff9965006a7f10] filp_close at ffffffff9b0e93f1 > #8 [ffff9965006a7f30] __x64_sys_close at ffffffff9b0e9a0e > #9 [ffff9965006a7f38] do_syscall_64 at ffffffff9ae04315 > > in __filemap_fdatawait_range > wait_on_page_writeback(page); > for the same page of the file > > > > [0 00:48:22.718] [UN] PID: 8855 TASK: ffff8c69142745c0 CPU: 7 > COMMAND: "reopen_file" > #0 [ffff9965005dfc98] __schedule at ffffffff9b6e6095 > #1 [ffff9965005dfd28] schedule at ffffffff9b6e64df > #2 [ffff9965005dfd38] rwsem_down_write_slowpath at ffffffff9af283d7 > #3 [ffff9965005dfdf0] cifs_strict_writev at ffffffffc0a0c40a [cifs] > #4 [ffff9965005dfe48] new_sync_write at ffffffff9b0ec1dd > #5 [ffff9965005dfed0] vfs_write at ffffffff9b0eed35 > #6 [ffff9965005dff00] ksys_write at ffffffff9b0eefd9 > #7 [ffff9965005dff38] do_syscall_64 at ffffffff9ae04315 > > inode_lock(inode); > > > and one 'ls' later on, to see whether the rest of the mount is available > (the test file is in the root, so we get blocked up on the directory > ->i_rwsem), so the entire mount is unavailable > > [0 00:36:26.473] [UN] PID: 9802 TASK: ffff8c691436ae80 CPU: 4 > COMMAND: "ls" > #0 [ffff996500393d28] __schedule at ffffffff9b6e6095 > #1 [ffff996500393db8] schedule at ffffffff9b6e64df > #2 [ffff996500393dc8] rwsem_down_read_slowpath at ffffffff9b6e9421 > #3 [ffff996500393e78] down_read_killable at ffffffff9b6e95e2 > #4 [ffff996500393e88] iterate_dir at ffffffff9b103c56 > #5 [ffff996500393ec8] ksys_getdents64 at ffffffff9b104b0c > #6 [ffff996500393f30] __x64_sys_getdents64 at ffffffff9b104bb6 > #7 [ffff996500393f38] do_syscall_64 at ffffffff9ae04315 > > in iterate_dir: > if (shared) > res = down_read_killable(&inode->i_rwsem); <<<< > else > res = down_write_killable(&inode->i_rwsem); > Reported-by: Frank Sorenson <sorenson@redhat.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@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: refactor cifs_get_inode_info()Aurelien Aptel
Make logic of cifs_get_inode() much clearer by moving code to sub functions and adding comments. Document the steps this function does. cifs_get_inode_info() gets and updates a file inode metadata from its file path. * If caller already has raw info data from server they can pass it. * If inode already exists (just need to update) caller can pass it. Step 1: get raw data from server if none was passed Step 2: parse raw data into intermediate internal cifs_fattr struct Step 3: set fattr uniqueid which is later used for inode number. This can sometime be done from raw data Step 4: tweak fattr according to mount options (file_mode, acl to mode bits, uid, gid, etc) Step 5: update or create inode from final fattr struct * add is_smb1_server() helper * add is_inode_cache_good() helper * move SMB1-backupcreds-getinfo-retry to separate func cifs_backup_query_path_info(). * move set-uniqueid code to separate func cifs_set_fattr_ino() * don't clobber uniqueid from backup cred retry * fix some probable corner cases memleaks Signed-off-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-11-25cifs: switch servers depending on binding stateAurelien Aptel
Currently a lot of the code to initialize a connection & session uses the cifs_ses as input. But depending on if we are opening a new session or a new channel we need to use different server pointers. Add a "binding" flag in cifs_ses and a helper function that returns the server ptr a session should use (only in the sess establishment code path). 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: add multichannel mount options and data structsAurelien Aptel
adds: - [no]multichannel to enable/disable multichannel - max_channels=N to control how many channels to create these options are then stored in the volume struct. - store channels and max_channels in cifs_ses Signed-off-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-11-25smb3: add debug messages for closing unmatched openRonnie Sahlberg
Helps distinguish between an interrupted close and a truly unmatched open. Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-11-25CIFS: Fix NULL pointer dereference in mid callbackPavel Shilovsky
There is a race between a system call processing thread and the demultiplex thread when mid->resp_buf becomes NULL and later is being accessed to get credits. It happens when the 1st thread wakes up before a mid callback is called in the 2nd one but the mid state has already been set to MID_RESPONSE_RECEIVED. This causes NULL pointer dereference in mid callback. Fix this by saving credits from the response before we update the mid state and then use this value in the mid callback rather then accessing a response buffer. Cc: Stable <stable@vger.kernel.org> Fixes: ee258d79159afed5 ("CIFS: Move credit processing to mid callbacks for SMB3") 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>
2019-10-24cifs: Fix cifsInodeInfo lock_sem deadlock when reconnect occursDave Wysochanski
There's a deadlock that is possible and can easily be seen with a test where multiple readers open/read/close of the same file and a disruption occurs causing reconnect. The deadlock is due a reader thread inside cifs_strict_readv calling down_read and obtaining lock_sem, and then after reconnect inside cifs_reopen_file calling down_read a second time. If in between the two down_read calls, a down_write comes from another process, deadlock occurs. CPU0 CPU1 ---- ---- cifs_strict_readv() down_read(&cifsi->lock_sem); _cifsFileInfo_put OR cifs_new_fileinfo down_write(&cifsi->lock_sem); cifs_reopen_file() down_read(&cifsi->lock_sem); Fix the above by changing all down_write(lock_sem) calls to down_write_trylock(lock_sem)/msleep() loop, which in turn makes the second down_read call benign since it will never block behind the writer while holding lock_sem. Signed-off-by: Dave Wysochanski <dwysocha@redhat.com> Suggested-by: Ronnie Sahlberg <lsahlber@redhat.com> Reviewed--by: Ronnie Sahlberg <lsahlber@redhat.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2019-10-08smb3: remove noisy debug message and minor cleanupSteve French
Message was intended only for developer temporary build In addition cleanup two minor warnings noticed by Coverity and a trivial change to workaround a sparse warning Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2019-09-26smb3: pass mode bits into create callsSteve French
We need to populate an ACL (security descriptor open context) on file and directory correct. This patch passes in the mode. Followon patch will build the open context and the security descriptor (from the mode) that goes in the open context. Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Aurelien Aptel <aaptel@suse.com>
2019-09-16cifs: Add support for root file systemsPaulo Alcantara (SUSE)
Introduce a new CONFIG_CIFS_ROOT option to handle root file systems over a SMB share. In order to mount the root file system during the init process, make cifs.ko perform non-blocking socket operations while mounting and accessing it. Cc: Steve French <smfrench@gmail.com> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Paulo Alcantara (SUSE) <paulo@paulo.ac> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-09-16smb3: allow disabling requesting leasesSteve French
In some cases to work around server bugs or performance problems it can be helpful to be able to disable requesting SMB2.1/SMB3 leases on a particular mount (not to all servers and all shares we are mounted to). Add new mount parm "nolease" which turns off requesting leases on directory or file opens. Currently the only way to disable leases is globally through a module load parameter. This is more granular. Suggested-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com> CC: Stable <stable@vger.kernel.org>
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>
2019-09-16smb3: enable offload of decryption of large reads via mount optionSteve French
Disable offload of the decryption of encrypted read responses by default (equivalent to setting this new mount option "esize=0"). Allow setting the minimum encrypted read response size that we will choose to offload to a worker thread - it is now configurable via on a new mount option "esize=" Depending on which encryption mechanism (GCM vs. CCM) and the number of reads that will be issued in parallel and the performance of the network and CPU on the client, it may make sense to enable this since it can provide substantial benefit when multiple large reads are in flight at the same time. Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
2019-09-16smb3: allow parallelizing decryption of readsSteve French
decrypting large reads on encrypted shares can be slow (e.g. adding multiple milliseconds per-read on non-GCM capable servers or when mounting with dialects prior to SMB3.1.1) - allow parallelizing of read decryption by launching worker threads. Testing to Samba on localhost showed 25% improvement. Testing to remote server showed very large improvement when doing more than one 'cp' command was called at one time. Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
2019-09-16smb3: allow skipping signature verification for perf sensitive configurationsSteve French
Add new mount option "signloosely" which enables signing but skips the sometimes expensive signing checks in the responses (signatures are calculated and sent correctly in the SMB2/SMB3 requests even with this mount option but skipped in the responses). Although weaker for security (and also data integrity in case a packet were corrupted), this can provide enough of a performance benefit (calculating the signature to verify a packet can be expensive especially for large packets) to be useful in some cases. Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
2019-09-16smb3: add mount option to allow RW caching of share accessed by only 1 clientSteve French
If a share is known to be only to be accessed by one client, we can aggressively cache writes not just reads to it. Add "cache=" option (cache=singleclient) for mounting read write shares (that will not be read or written to from other clients while we have it mounted) in order to improve performance. Signed-off-by: Steve French <stfrench@microsoft.com>
2019-09-16smb3: add mount option to allow forced caching of read only shareSteve French
If a share is immutable (at least for the period that it will be mounted) it would be helpful to not have to revalidate dentries repeatedly that we know can not be changed remotely. Add "cache=" option (cache=ro) for mounting read only shares in order to improve performance in cases in which we know that the share will not be changing while it is in use. Signed-off-by: Steve French <stfrench@microsoft.com>
2019-07-07smb3: do not send compression info by defaultSteve French
Since in theory a server could respond with compressed read responses even if not requested on read request (assuming that a compression negcontext is sent in negotiate protocol) - do not send compression information during negotiate protocol unless the user asks for compression explicitly (compression is experimental), and add a mount warning that compression is experimental. Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>