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>
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>
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>
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>
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>
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>
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: 8de9e86c67 ("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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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: ee258d7915 ("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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
There is a special ACE used by some servers to allow the mode
bits to be stored. This can be especially helpful in scenarios
in which the client is trusted, and access checking on the
client vs the POSIX mode bits is sufficient.
Add mount option to allow enabling this behavior.
Follow on patch will add support for chmod and queryinfo
(stat) by retrieving the POSIX mode bits from the special
ACE, SID: S-1-5-88-3
See e.g.
https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2008-R2-and-2008/hh509017(v=ws.10)
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
SMB3 ACL support is needed for many use cases now and should not be
ifdeffed out, even for SMB1 (CIFS). Remove the CONFIG_CIFS_ACL
ifdef so ACL support is always built into cifs.ko
Signed-off-by: Steve French <stfrench@microsoft.com>
If we mount the same share twice, we check the flags to see if the
second mount matches the earlier mount, but we left some flags out.
Signed-off-by: Steve French <stfrench@microsoft.com>
We can not depend on the tcon->open_file_lock here since in multiuser mode
we may have the same file/inode open via multiple different tcons.
The current code is race prone and will crash if one user deletes a file
at the same time a different user opens/create the file.
To avoid this we need to have a spinlock attached to the inode and not the tcon.
RHBZ: 1580165
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Add llseek op for SEEK_DATA and SEEK_HOLE.
Improves xfstests/285,286,436,445,448 and 490
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Two of the common symlink formats use reparse points
(unlike mfsymlinks and also unlike the SMB1 posix
extensions). This is the first part of the fixes
to allow these reparse points (NFS style and Windows
symlinks) to be resolved properly as symlinks by the
client.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
New negotiate context (3) allows the server and client to
negotiate which compression algorithms to use. Add support
for this and save it off in the server structure.
Also now displayed in /proc/fs/cifs/DebugData (see below example
to Windows 10) where compression algoirthm "LZ77" was negotiated:
Servers:
Number of credits: 326 Dialect 0x311 COMPRESS_LZ77 signed
1) Name: 192.168.92.17 Uses: 1 Capability: 0x300067 Session Status: 1 TCP status: 1 Instance: 1
See MS-XCA and MS-SMB2 2.2.3.1 for more details.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
The flags were named confusingly.
CIFS_ASYNC_OP now just means that we will not block waiting for credits
to become available so we thus rename this to be CIFS_NON_BLOCKING.
Change CIFS_NO_RESP to CIFS_NO_RSP_BUF to clarify that we will actually get a
response from the server but we will not get/do not want a response buffer.
Delete CIFSSMBNotify. This is an SMB1 function that is not used.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
For SMB1 oplock breaks we would grab one credit while sending the PDU
but we would never relese the credit back since we will never receive a
response to this from the server. Eventuallt this would lead to a hang
once all credits are leaked.
Fix this by defining a new flag CIFS_NO_SRV_RSP which indicates that there
is no server response to this command and thus we need to add any credits back
immediately after sending the PDU.
CC: Stable <stable@vger.kernel.org> #v5.0+
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Useful for improved copy performance as well as for
applications which query allocated ranges of sparse
files.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
if we mount A then mount A again with nodfs, we shouldn't reuse the
superblock. document the purpose of the defines as well.
there are most likely more flags that needs to be added to this mask,
in fact the logic to find them should be which flag should
be *ignored* when trying to reuse an existing sb.
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
In the oplock break handler, writing pending changes from pages puts
the FileInfo handle. If the refcount reaches zero it closes the handle
and waits for any oplock break handler to return, thus causing a deadlock.
To prevent this situation:
* We add a wait flag to cifsFileInfo_put() to decide whether we should
wait for running/pending oplock break handlers
* We keep an additionnal reference of the SMB FileInfo handle so that
for the rest of the handler putting the handle won't close it.
- The ref is bumped everytime we queue the handler via the
cifs_queue_oplock_break() helper.
- The ref is decremented at the end of the handler
This bug was triggered by xfstest 464.
Also important fix to address the various reports of
oops in smb2_push_mandatory_locks
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Reconnecting after server or network failure can be improved
(to maintain availability and protect data integrity) by allowing
the client to choose the default persistent (or resilient)
handle timeout in some use cases. Today we default to 0 which lets
the server pick the default timeout (usually 120 seconds) but this
can be problematic for some workloads. Add the new mount parameter
to cifs.ko for SMB3 mounts "handletimeout" which enables the user
to override the default handle timeout for persistent (mount
option "persistenthandles") or resilient handles (mount option
"resilienthandles"). Maximum allowed is 16 minutes (960000 ms).
Units for the timeout are expressed in milliseconds. See
section 2.2.14.2.12 and 2.2.31.3 of the MS-SMB2 protocol
specification for more information.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
CC: Stable <stable@vger.kernel.org>
This cleanup removes cifs specific code from SMB2/SMB3 code paths
which is cleaner and easier to maintain as the code to handle
special files is improved. Below is an example creating special files
using 'sfu' mount option over SMB3 to Windows (with this patch)
(Note that to Samba server, support for saving dos attributes
has to be enabled for the SFU mount option to work).
In the future this will also make implementation of creating
special files as reparse points easier (as Windows NFS server does
for example).
root@smf-Thinkpad-P51:~# stat -c "%F" /mnt2/char
character special file
root@smf-Thinkpad-P51:~# stat -c "%F" /mnt2/block
block special file
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
When we open the shared root handle also ask for FILE_ALL_INFORMATION since
we can do this at zero cost as part of a compound.
Cache this information as long as the lease is held and return and serve any
future requests from cache.
This allows us to serve "stat /<mountpoint>" directly from cache and avoid
a network roundtrip. Since clients often want to do this quite a lot
this improve performance slightly.
As an example: xfstest generic/533 performs 43 stat operations on the root
of the share while it is run. Which are eliminated with this patch.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Change wait_for_free_credits() to allow waiting for >=1 credits instead of just
a single credit.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Currently we adjust MTU credits before sending an IO request
and after reopening a file. This approach doesn't allow the
reopen routine to use existing credits that are not needed
for IO. Reorder credit adjustment and reopening a file to
use credits available to the client more efficiently. Also
unwrap complex if statement into few pieces to improve
readability.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Every time after a session reconnect we don't need to account for
credits obtained in previous sessions. Make use of the recently
added cifs_credits structure to properly calculate credits for
non-MTU requests the same way we did for MTU ones.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Every time after a session reconnect we don't need to account for
credits obtained in previous sessions. Introduce new struct cifs_credits
which contains both credits value and reconnect instance of the
time those credits were taken. Modify a routine that add credits
back to handle the reconnect instance by assuming zero credits
if the reconnect happened after the credits were obtained and
before we decided to add them back due to some errors during sending.
This patch fixes the MTU credits cases. The subsequent patch
will handle non-MTU ones.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Even if a response is malformed, we should count credits
granted by the server to avoid miscalculations and unnecessary
reconnects due to client or server bugs. If the response has
been received partially, the session will be reconnected anyway
on the next iteration of the demultiplex thread, so counting
credits for such cases shouldn't break things.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
When we hit failures during constructing MIDs or sending PDUs
through the network, we end up not using message IDs assigned
to the packet. The next SMB packet will skip those message IDs
and continue with the next one. This behavior may lead to a server
not granting us credits until we use the skipped IDs. Fix this by
reverting the current ID to the original value if any errors occur
before we push the packet through the network stack.
This patch fixes the generic/310 test from the xfs-tests.
Cc: <stable@vger.kernel.org> # 4.19.x
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
We negotiate rsize mounts (and it can be overridden by user) to
typically 4MB, so using larger default I/O sizes from userspace
(changing to 1MB default i/o size returned by stat) the
performance is much better (and not just for long latency
network connections) in most use cases for SMB3 than the default I/O
size (which ends up being 128K for cp and can be even smaller for cp).
This can be 4x slower or worse depending on network latency.
By changing inode->blocksize from 32K (which was perhaps ok
for very old SMB1/CIFS) to a larger value, 1MB (but still less than
max size negotiated with the server which is 4MB, in order to minimize
risk) it significantly increases performance for the
noncached case, and slightly increases it for the cached case.
This can be changed by the user on mount (specifying bsize=
values from 16K to 16MB) to tune better for performance
for applications that depend on blocksize.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
CC: Stable <stable@vger.kernel.org>
This patch aims to address writeback code problems related to error
paths. In particular it respects EINTR and related error codes and
stores and returns the first error occurred during writeback.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Acked-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
If a request is cancelled, we can't assume that the server returns
1 credit back. Instead we need to wait for a response and process
the number of credits granted by the server.
Create a separate mid callback for cancelled request, parse the number
of credits in a response buffer and add them to the client's credits.
If the didn't get a response (no response buffer available) assume
0 credits granted. The latter most probably happens together with
session reconnect, so the client's credits are adjusted anyway.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
After failing to reconnect to original target, it will retry any
target available from DFS cache.
Signed-off-by: Paulo Alcantara <palcantara@suse.de>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
This patch will make use of DFS cache routines where appropriate and
do not always request a new referral from server.
Signed-off-by: Paulo Alcantara <palcantara@suse.de>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
* Add new dfs_cache.[ch] files
* Add new /proc/fs/cifs/dfscache file
- dump current cache when read
- clear current cache when writing "0" to it
* Add delayed_work to periodically refresh cache entries
The new interface will be used for caching DFS referrals, as well as
supporting client target failover.
The DFS cache is a hashtable that maps UNC paths to cache entries.
A cache entry contains:
- the UNC path it is mapped on
- how much the the UNC path the entry consumes
- flags
- a Time-To-Live after which the entry expires
- a list of possible targets (linked lists of UNC paths)
- a "hint target" pointing the last known working target or the first
target if none were tried. This hint lets cifs.ko remember and try
working targets first.
* Looking for an entry in the cache is done with dfs_cache_find()
- if no valid entries are found, a DFS query is made, stored in the
cache and returned
- the full target list can be copied and returned to avoid race
conditions and looped on with the help with the
dfs_cache_tgt_iterator
* Updating the target hint to the next target is done with
dfs_cache_update_tgthint()
These functions have a dfs_cache_noreq_XXX() version that doesn't
fetches referrals if no entries are found. These versions don't
require the tcp/ses/tcon/cifs_sb parameters as a result.
Expired entries cannot be used and since they have a pretty short TTL
[1] in order for them to be useful for failover the DFS cache adds a
delayed work called periodically to keep them fresh.
Since we might not have available connections to issue the referral
request when refreshing we need to store volume_info structs with
credentials and other needed info to be able to connect to the right
server.
1: Windows defaults: 5mn for domain-based referrals, 30mn for regular
links
Signed-off-by: Paulo Alcantara <palcantara@suse.de>
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
This will be needed by DFS cache.
Signed-off-by: Paulo Alcantara <palcantara@suse.de>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Technically 3.02 is not the dialect name although that is more familiar to
many, so we should also accept the official dialect name (3.0.2 vs. 3.02)
in vers=
Signed-off-by: Kenneth D'souza <kdsouza@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
With direct I/O read, we transfer the data directly from transport layer to
the user data buffer.
Change in v3: add support for kernel AIO
Change in v4:
Refactor common read code to __cifs_readv for direct and non-direct I/O.
Retry on direct I/O failure.
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
In order to debug complex problems it is often helpful to
have detailed information on the client and server view
of the open file information. Add the ability for root to
view the list of smb3 open files and dump the persistent
handle and other info so that it can be more easily
correlated with server logs.
Sample output from "cat /proc/fs/cifs/open_files"
# Version:1
# Format:
# <tree id> <persistent fid> <flags> <count> <pid> <uid> <filename> <mid>
0x5 0x800000378 0x8000 1 7704 0 some-file 0x14
0xcb903c0c 0x84412e67 0x8000 1 7754 1001 rofile 0x1a6d
0xcb903c0c 0x9526b767 0x8000 1 7720 1000 file 0x1a5b
0xcb903c0c 0x9ce41a21 0x8000 1 7715 0 smallfile 0xd67
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
To allow better debugging (for example applications with
handle leaks, or complex reconnect scenarios) display the
number of open files (on the client) and number of open
server file handles for each tcon in /proc/fs/cifs/Stats.
Note that open files on server is one larger than local
due to handle caching (in this case of the root of
the share). In this example there are two local
open files, and three (two file and one directory handle)
open on the server.
Sample output:
$ cat /proc/fs/cifs/Stats
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: 36 maximum at one time: 2
1) \\localhost\test
SMBs: 69
Bytes read: 27 Bytes written: 0
Open files: 2 total (local), 3 open on server
TreeConnects: 1 total 0 failed
TreeDisconnects: 0 total 0 failed
Creates: 19 total 0 failed
Closes: 16 total 0 failed
...
Signed-off-by: Steve French <stfrench@microsoft.com>
We do not call cifs_open_file() for directories and thus we do not have a
pSMBFile we can extract the FIDs from.
Solve this by instead always using a compounded open/query/close for
the passthrough ioctl.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
This allows userspace tools to query the raw info levels for cifs files
and process the response in userspace.
In particular this is useful for many of those data where there is no
corresponding native data structure in linux.
For example querying the security descriptor for a file and extract the
SIDs.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
RHBZ 1484130
Update cifs_find_fid_lock_conflict() to recognize that
ODF locks do not conflict with eachother.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Modern servers often support 8MB as maximum i/o size, and we see some
performance benefits (my testing showed 1 to 13% on write paths,
and 1 to 3% on read paths for increasing the default to 4MB). If server
doesn't support larger i/o size, during negotiate protocol it is already
set correctly to the server's maximum if lower than 4MB.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Each time we reconnect to the same server, bump an instance
counter (and display in /proc/fs/cifs/DebugData) to make it
easier to debug.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
/proc/fs/cifs/Stats when CONFIG_CIFS_STATS2 is enabled logs 'slow'
responses, but depending on the server you are debugging a
one second timeout may be too fast, so allow setting it to
a larger number of seconds via new module parameter
/sys/module/cifs/parameters/slow_rsp_threshold
or via modprobe:
slow_rsp_threshold:Amount of time (in seconds) to wait before
logging that a response is delayed.
Default: 1 (if set to 0 disables msg). (uint)
Recommended values are 0 (disabled) to 32767 (9 hours) with
the default remaining as 1 second.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
cifs_delete_mid() is called once we are finished handling a mid and we
expect no more work done on this mid.
Needed to fix recent commit:
commit 730928c8f4
("cifs: update smb2_queryfs() to use compounding")
Add a warning if someone tries to dequeue a mid that has already been
flagged to be deleted.
Also change list_del() to list_del_init() so that if we have similar bugs
resurface in the future we will not oops.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Paulo Alcantara <palcantara@suse.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
When CONFIG_CIFS_STATS2 is enabled keep counters for slow
commands (ie server took longer than 1 second to respond)
by SMB2/SMB3 command code. This can help in diagnosing
whether performance problems are on server (instead of
client) and which commands are causing the problem.
Sample output (the new lines contain words "slow responses ...")
$ cat /proc/fs/cifs/Stats
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
Total Large 10 Small 490 Allocations
Operations (MIDs): 0
0 session 0 share reconnects
Total vfs operations: 67 maximum at one time: 2
4 slow responses from localhost for command 5
1 slow responses from localhost for command 6
1 slow responses from localhost for command 14
1 slow responses from localhost for command 16
1) \\localhost\test
SMBs: 243
Bytes read: 1024000 Bytes written: 104857600
TreeConnects: 1 total 0 failed
TreeDisconnects: 0 total 0 failed
Creates: 40 total 0 failed
Closes: 39 total 0 failed
...
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
These are used for SMB3 encryption and compounded requests.
Update these functions and the other functions related to SMB3 encryption to
take an array of requests.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
CONFIG_CIFS_STATS should always be enabled as Pavel recently
noted. Simple statistics are not a significant performance hit,
and removing the ifdef simplifies the code slightly.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@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>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Cc: <stable@vger.kernel.org>
These timers were a good idea but weren't used in current code,
and the idea was cifs specific. Future patch will add similar timers
for SMB2/SMB3, but no sense using memory for cifs timers that
aren't used in current code.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
We really, really want to be encouraging use of secure dialects,
and SMB3.1.1 offers useful security features, and will soon
be the recommended dialect for many use cases. Simplify the code
by removing the CONFIG_CIFS_SMB311 ifdef so users don't disable
it in the build, and create compatibility and/or security issues
with modern servers - many of which have been supporting this
dialect for multiple years.
Also clarify some of the Kconfig text for cifs.ko about
SMB3.1.1 and current supported features in the module.
Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
In cifs, the timestamps are stored in memory in the cifs_fattr structure,
which uses the deprecated 'timespec' structure. Now that the VFS code
has moved on to 'timespec64', the next step is to change over the fattr
as well.
This also makes 32-bit and 64-bit systems behave the same way, and
no longer overflow the 32-bit time_t in year 2038.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Paulo Alcantara <palcantara@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
With protocol version 2.0 mounts we have seen crashes with corrupt mid
entries. Either the server->pending_mid_q list becomes corrupt with a
cyclic reference in one element or a mid object fetched by the
demultiplexer thread becomes overwritten during use.
Code review identified a race between the demultiplexer thread and the
request issuing thread. The demultiplexer thread seems to be written
with the assumption that it is the sole user of the mid object until
it calls the mid callback which either wakes the issuer task or
deletes the mid.
This assumption is not true because the issuer task can be woken up
earlier by a signal. If the demultiplexer thread has proceeded as far
as setting the mid_state to MID_RESPONSE_RECEIVED then the issuer
thread will happily end up calling cifs_delete_mid while the
demultiplexer thread still is using the mid object.
Inserting a delay in the cifs demultiplexer thread widens the race
window and makes reproduction of the race very easy:
if (server->large_buf)
buf = server->bigbuf;
+ usleep_range(500, 4000);
server->lstrp = jiffies;
To resolve this I think the proper solution involves putting a
reference count on the mid object. This patch makes sure that the
demultiplexer thread holds a reference until it has finished
processing the transaction.
Cc: stable@vger.kernel.org
Signed-off-by: Lars Persson <larper@axis.com>
Acked-by: Paulo Alcantara <palcantara@suse.de>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Use a read lease for the cached root fid so that we can detect
when the content of the directory changes (via a break) at which time
we close the handle. On next access to the root the handle will be reopened
and cached again.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
cifs->master_tlink is NULL against Win Server 2016 (which is
strange.. not sure why) and is dereferenced in cifs_sb_master_tcon().
move master_tlink getter to cifsglob.h so it can be used from
smb2misc.c
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Pavel Shilovsky <pshilov@microsoft.com>
Add a function to allocate wdata without allocating pages for data
transfer. This gives the caller an option to pass a number of pages that
point to the data buffer to write to.
wdata is reponsible for free those pages after it's done.
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Add a function to allocate rdata without allocating pages for data
transfer. This gives the caller an option to pass a number of pages
that point to the data buffer.
rdata is still reponsible for free those pages after it's done.
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
If "posix" (or synonym "unix" for backward compatibility) specified on mount,
and server advertises support for SMB3.11 POSIX negotiate context, then
enable the new posix extensions on the tcon. This can be viewed by
looking for "posix" in the mount options displayed by /proc/mounts
for that mount (ie if posix extensions allowed by server and the
experimental POSIX extensions also requested on the mount by specifying
"posix" at mount time).
Also add check to warn user if conflicting unix/nounix or posix/noposix specified
on mount.
Signed-off-by: Steve French <smfrench@gmail.com>
Unlike CIFS where UNIX/POSIX extensions had been negotiatable,
SMB3 did not have POSIX extensions yet. Add the new SMB3.11
POSIX negotiate context to ask the server whether it can
support POSIX (and thus whether we can send the new POSIX open
context).
Signed-off-by: Steve French <smfrench@gmail.com>
To improve security it may be helpful to have additional ways to restrict the
ability to override the default dialects (SMB2.1, SMB3 and SMB3.02) on mount
with old dialects (CIFS/SMB1 and SMB2) since vers=1.0 (CIFS/SMB1) and vers=2.0
are weaker and less secure.
Add a module parameter "disable_legacy_dialects"
(/sys/module/cifs/parameters/disable_legacy_dialects) which can be set to
1 (or equivalently Y) to forbid use of vers=1.0 or vers=2.0 on mount.
Also cleans up a few build warnings about globals for various module parms.
Signed-off-by: Steve French <smfrench@gmail.com>
Note which ones of the module params are cifs dialect only
(N/A for default dialect now that has moved to SMB2.1 or later)
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
When direct I/O is used, the data buffer may not always align to page
boundaries. Introduce a page offset in transport data structures to
describe the location of the buffer within the page.
Also change the function to pass the page offset when sending data to
transport.
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
In SMB2_open(), if we got a lease we need to store this in the fid structure
or else we will never be able to map a lease break back to which file/fid
it applies to.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
and change the smb2 version to take heder_preamble_size into account
instead of hardcoding it as 4 bytes.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
We need a struct TCP_Server_Info *server to this method as it calls
calc_size. The calc_size method will soon be changed to also
take a server argument.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
In SMB2/SMB3 unlike in cifs we unnecessarily open the root of the share
over and over again in various places during mount and path revalidation
and also in statfs. This patch cuts redundant traffic (opens and closes)
by simply keeping the directory handle for the root around (and reopening
it as needed on reconnect), so query calls don't require three round
trips to copmlete - just one, and eases load on network, client and
server (on mount alone, cuts network traffic by more than a third).
Also add a new cifs mount parm "nohandlecache" to allow users whose
servers might have resource constraints (eg in case they have a server
with so many users connecting to it that this extra handle per mount
could possibly be a resource concern).
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
and get rid of some more calls to get_rfc1002_length()
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
and get rid of some get_rfc1002_length() in smb2
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
SMB3.11 crypto and hash contexts were not being checked strictly enough.
Add parsing and validity checking for the security contexts in the SMB3.11
negotiate response.
Signed-off-by: Steve French <smfrench@gmail.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Some servers return inode number zero for the root directory, which
causes ls to display incorrect data (missing "." and "..").
If the server returns zero for the inode number of the root directory,
fake an inode number for it.
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
CC: Stable <stable@vger.kernel.org>
This variable is set to 4 for all protocol versions and replaces
the hardcoded constant 4 throughought the code.
This will later be updated to reflect whether a response packet
has a 4 byte length preamble or not once we start removing this
field from the SMB2+ dialects.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
SMB3.11 clients must implement pre-authentification integrity.
* new mechanism to certify requests/responses happening before Tree
Connect.
* supersedes VALIDATE_NEGOTIATE
* fixes signing for SMB3.11
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <smfrench@gmail.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
* prepare for SMB3.11 pre-auth integrity
* enable sha512 when SMB311 is enabled in Kconfig
* add sha512 as a soft dependency
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <smfrench@gmail.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
* Remove ses->ipc_tid.
* Make IPC$ regular tcon.
* Add a direct pointer to it in ses->tcon_ipc.
* Distinguish PIPE tcon from IPC tcon by adding a tcon->pipe flag. All
IPC tcons are pipes but not all pipes are IPC.
* All TreeConnect functions now cannot take a NULL tcon object.
The IPC tcon has the same lifetime as the session it belongs to. It is
created when the session is created and destroyed when the session is
destroyed.
Since no mounts directly refer to the IPC tcon, its refcount should
always be set to initialisation value (1). Thus we make sure
cifs_put_tcon() skips it.
If the mount request resulting in a new session being created requires
encryption, try to require it too for IPC.
* set SERVER_NAME_LENGTH to serverName actual size
The maximum length of an ipv6 string representation is defined in
INET6_ADDRSTRLEN as 45+1 for null but lets keep what we know works.
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
This patch is for preparing upper layer doing SMB read via RDMA write.
When RDMA write is used for SMB read, the returned data length is in
DataRemaining in the response packet. Reading it properly by adding a
parameter to specifiy where the returned data length is.
Add the defition for memory registration to wdata and return the correct
length based on if RDMA write is used.
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
When sending I/O, if size is larger than rdma_readwrite_threshold we prepare
to send SMB write packet for a RDMA read via memory registration. The actual
I/O is done by remote peer through local RDMA hardware. Modify the relevant
fields in the packet accordingly, and append a smbd_buffer_descriptor_v1 to
the end of the SMB write packet.
On write I/O finish, deregister the memory region if this was for a RDMA read.
If remote invalidation is not used, the call to smbd_deregister_mr will do
local invalidation and possibly wait. Memory region is normally deregistered
in MID callback as soon as it's used. There are situations where the MID may
not be created on I/O failure, under which memory region is deregistered when
write data context is released.
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Add "rdma" to CIFS mount options to connect to SMB Direct.
Add checks to validate this is used on SMB 3.X dialects.
To connect to SMBDirect, use "mount.cifs -o rdma,vers=3.x".
At the time of this patch, 3.x can be 3.0, 3.02 or 3.1.1.
Signed-off-by: Long Li <longli@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Acked-by: Ronnie Sahlberg <lsahlber.redhat.com>
This is a pure automated search-and-replace of the internal kernel
superblock flags.
The s_flags are now called SB_*, with the names and the values for the
moment mirroring the MS_* flags that they're equivalent to.
Note how the MS_xyz flags are the ones passed to the mount system call,
while the SB_xyz flags are what we then use in sb->s_flags.
The script to do this was:
# places to look in; re security/*: it generally should *not* be
# touched (that stuff parses mount(2) arguments directly), but
# there are two places where we really deal with superblock flags.
FILES="drivers/mtd drivers/staging/lustre fs ipc mm \
include/linux/fs.h include/uapi/linux/bfs_fs.h \
security/apparmor/apparmorfs.c security/apparmor/include/lib.h"
# the list of MS_... constants
SYMS="RDONLY NOSUID NODEV NOEXEC SYNCHRONOUS REMOUNT MANDLOCK \
DIRSYNC NOATIME NODIRATIME BIND MOVE REC VERBOSE SILENT \
POSIXACL UNBINDABLE PRIVATE SLAVE SHARED RELATIME KERNMOUNT \
I_VERSION STRICTATIME LAZYTIME SUBMOUNT NOREMOTELOCK NOSEC BORN \
ACTIVE NOUSER"
SED_PROG=
for i in $SYMS; do SED_PROG="$SED_PROG -e s/MS_$i/SB_$i/g"; done
# we want files that contain at least one of MS_...,
# with fs/namespace.c and fs/pnode.c excluded.
L=$(for i in $SYMS; do git grep -w -l MS_$i $FILES; done| sort|uniq|grep -v '^fs/namespace.c'|grep -v '^fs/pnode.c')
for f in $L; do sed -i $f $SED_PROG; done
Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
SMB3.1.1 is most secure and recent dialect. Fixup labels and lengths
for sMB3.1.1 signing and encryption.
Signed-off-by: Steve French <smfrench@gmail.com>
CC: Stable <stable@vger.kernel.org>
With the need to discourage use of less secure dialect, SMB1 (CIFS),
we temporarily upgraded the dialect to SMB3 in 4.13, but since there
are various servers which only support SMB2.1 (2.1 is more secure
than CIFS/SMB1) but not optimal for a default dialect - add support
for multidialect negotiation. cifs.ko will now request SMB2.1
or later (ie SMB2.1 or SMB3.0, SMB3.02) and the server will
pick the latest most secure one it can support.
In addition since we are sending multidialect negotiate, add
support for secure negotiate to validate that a man in the
middle didn't downgrade us.
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
CC: Stable <stable@vger.kernel.org> # 4.13+
This adds support for writing extended attributes on SMB2+ shares.
Attributes can be written using the setfattr command.
RH-bz: 1110709
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Remove the CONFIG_CIFS_SMB2 ifdef and Kconfig option since they
must always be on now.
For various security reasons, SMB3 and later are STRONGLY preferred
over CIFS and older dialects, and SMB3 (and later) will now be
the default dialects so we do not want to allow them to be
ifdeffed out.
In the longer term, we may be able to make older CIFS support
disableable in Kconfig with a new set of #ifdef, but we always
want SMB3 and later support enabled.
Signed-off-by: Steven French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
According to the MS-SMB2 spec (3.2.5.1.6) once the client receives
STATUS_NETWORK_SESSION_EXPIRED error code from a server it should
reconnect the current SMB session. Currently the client doesn't do
that. This can result in subsequent client requests failing by
the server. The patch adds an additional logic to the demultiplex
thread to identify expired sessions and reconnect them.
Cc: <stable@vger.kernel.org>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Some minor cleanup of cifs query xattr functions (will also make
SMB3 xattr implementation cleaner as well).
Signed-off-by: Steve French <steve.french@primarydata.com>
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>
This patch adds support to process write calls passed by io_submit()
asynchronously. It based on the previously introduced async context
that allows to process i/o responses in a separate thread and
return the caller immediately for asynchronous calls.
This improves writing performance of single threaded applications
with increasing of i/o queue depth size.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
This patch adds support to process read calls passed by io_submit()
asynchronously. It based on the previously introduced async context
that allows to process i/o responses in a separate thread and
return the caller immediately for asynchronous calls.
This improves reading performance of single threaded applications
with increasing of i/o queue depth size.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Currently the code doesn't recognize asynchronous calls passed
by io_submit() and processes all calls synchronously. This is not
what kernel AIO expects. This patch introduces a new async context
that keeps track of all issued i/o requests and moves a response
collecting procedure to a separate thread. This allows to return
to a caller immediately for async calls and call iocb->ki_complete()
once all requests are completed. For sync calls the current thread
simply waits until all requests are completed.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
STATUS_BAD_NETWORK_NAME can be received during node failover,
causing the flag to be set and making the reconnect thread
always unsuccessful, thereafter.
Once the only place where it is set is removed, the remaining
bits are rendered moot.
Removing it does not prevent "mount" from failing when a non
existent share is passed.
What happens when the share really ceases to exist while the
share is mounted is undefined now as much as it was before.
Signed-off-by: Germano Percossi <germano.percossi@citrix.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <smfrench@gmail.com>
The earlier changes to copy range for cifs unintentionally disabled the more
common form of server side copy.
The patch introduces the file_operations helper cifs_copy_file_range()
which is used by the syscall copy_file_range. The new file operations
helper allows us to perform server side copies for SMB2.0 and 2.1
servers as well as SMB 3.0+ servers which do not support the ioctl
FSCTL_DUPLICATE_EXTENTS_TO_FILE.
The new helper uses the ioctl FSCTL_SRV_COPYCHUNK_WRITE to perform
server side copies. The helper is called by vfs_copy_file_range() only
once an attempt to clone the file using the ioctl
FSCTL_DUPLICATE_EXTENTS_TO_FILE has failed.
Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <smfrench@gmail.com>
Server side copy is one of the most important mechanisms smb2/smb3
supports and it was unintentionally disabled for most use cases.
Renaming calls to reflect the underlying smb2 ioctl called. This is
similar to the name duplicate_extents used for a similar ioctl which is
also used to duplicate files by reusing fs blocks. The name change is to
avoid confusion.
Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
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>
If the security type specified using a mount option is not supported,
the SMB2 session setup code changes the security type to RawNTLMSSP. We
should instead fail the mount and return an error.
The patch changes the code for SMB2 to make it similar to the code used
for SMB1. Like in SMB1, we now use the global security flags to select
the security method to be used when no security method is specified and
to return an error when the requested auth method is not available.
For SMB2, we also use ntlmv2 as a synonym for nltmssp.
Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Acked-by: Pavel Shilovsky <pshilov@microsoft.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
the TreeId field went from 2 bytes in CIFS to 4 bytes in SMB2+. this
commit updates the size of the ipc_tid field of a cifs_ses, which was
still using 2 bytes.
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Since we have two different types of reads (pagecache and direct)
we need to process such responses differently after decryption of
a packet. The change allows to specify a callback that copies a read
payload data into preallocated pages.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
We need to process read responses differently because the data
should go directly into preallocated pages. This can be done
by specifying a mid handle callback.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
We need to recognize and parse transformed packets in demultiplex
thread to find a corresponsing mid and process it further.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
This change allows to encrypt packets if it is required by a server
for SMB sessions or tree connections.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
This will allow us to do protocol specific tranformations of packets
before sending to the server. For SMB3 it can be used to support
encryption.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
In order to simplify further encryption support we need to separate
RFC1001 length and SMB2 header when sending a request. Put the length
field in iov[0] and the rest of the packet into following iovs.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
With commit 2b149f119 many things have been fixed/introduced.
However, the default behaviour for RawNTLMSSP authentication
seems to be wrong in case the domain is not passed on the command line.
The main points (see below) of the patch are:
- It alignes behaviour with Windows clients
- It fixes backward compatibility
- It fixes UPN
I compared this behavour with the one from a Windows 10 command line
client. When no domains are specified on the command line, I traced
the packets and observed that the client does send an empty
domain to the server.
In the linux kernel case, the empty domain is replaced by the
primary domain communicated by the SMB server.
This means that, if the credentials are valid against the local server
but that server is part of a domain, then the kernel module will
ask to authenticate against that domain and we will get LOGON failure.
I compared the packet trace from the smbclient when no domain is passed
and, in that case, a default domain from the client smb.conf is taken.
Apparently, connection succeeds anyway, because when the domain passed
is not valid (in my case WORKGROUP), then the local one is tried and
authentication succeeds. I tried with any kind of invalid domain and
the result was always a connection.
So, trying to interpret what to do and picking a valid domain if none
is passed, seems the wrong thing to do.
To this end, a new option "domainauto" has been added in case the
user wants a mechanism for guessing.
Without this patch, backward compatibility also is broken.
With kernel 3.10, the default auth mechanism was NTLM.
One of our testing servers accepted NTLM and, because no
domains are passed, authentication was local.
Moving to RawNTLMSSP forced us to change our command line
to add a fake domain to pass to prevent this mechanism to kick in.
For the same reasons, UPN is broken because the domain is specified
in the username.
The SMB server will work out the domain from the UPN and authenticate
against the right server.
Without the patch, though, given the domain is empty, it gets replaced
with another domain that could be the wrong one for the authentication.
Signed-off-by: Germano Percossi <germano.percossi@citrix.com>
Acked-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
With the current code it is possible to lock a mutex twice when
a subsequent reconnects are triggered. On the 1st reconnect we
reconnect sessions and tcons and then persistent file handles.
If the 2nd reconnect happens during the reconnecting of persistent
file handles then the following sequence of calls is observed:
cifs_reopen_file -> SMB2_open -> small_smb2_init -> smb2_reconnect
-> cifs_reopen_persistent_file_handles -> cifs_reopen_file (again!).
So, we are trying to acquire the same cfile->fh_mutex twice which
is wrong. Fix this by moving reconnecting of persistent handles to
the delayed work (smb2_reconnect_server) and submitting this work
every time we reconnect tcon in SMB2 commands handling codepath.
This can also lead to corruption of a temporary file list in
cifs_reopen_persistent_file_handles() because we can recursively
call this function twice.
Cc: Stable <stable@vger.kernel.org> # v4.9+
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
We can not unlock/lock cifs_tcp_ses_lock while walking through ses
and tcon lists because it can corrupt list iterator pointers and
a tcon structure can be released if we don't hold an extra reference.
Fix it by moving a reconnect process to a separate delayed work
and acquiring a reference to every tcon that needs to be reconnected.
Also do not send an echo request on newly established connections.
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
New mount option "snapshot=<time>" to allow mounting an earlier
version of the remote volume (if such a snapshot exists on
the server).
Note that eventually specifying a snapshot time of 1 will allow
the user to mount the oldest snapshot. A subsequent patch
add the processing for that and another for actually specifying
the "time warp" create context on SMB2/SMB3 open.
Check to make sure SMB2 negotiated, and ensure that
we use a different tcon if mount same share twice
but with different snaphshot times
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Add "idsfromsid" mount option to indicate to cifs.ko that it should
try to retrieve the uid and gid owner fields from special sids in the
ACL if present. This first patch just adds the parsing for the mount
option.
Signed-off-by: Steve French <steve.french@primarydata.com>
Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
openFileList of tcon can be changed while cifs_reopen_file() is called
that can lead to an unexpected behavior when we return to the loop.
Fix this by introducing a temp list for keeping all file handles that
need to be reopen.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Add mount option "max_credits" to allow setting maximum SMB3
credits to any value from 10 to 64000 (default is 32000).
This can be useful to workaround servers with problems allocating
credits, or to throttle the client to use smaller amount of
simultaneous i/o or to workaround server performance issues.
Also adds a cap, so that even if the server granted us more than
65000 credits due to a server bug, we would not use that many.
Signed-off-by: Steve French <steve.french@primarydata.com>
Kenneth D'souza