When connecting over SMB Direct, the transport negotiates its maximum I/O sizes
with the server and determines how to choose to do RDMA send/recv vs
read/write. Expose these maximum I/O sizes to upper layer so we will get the
correct sized payloads.
Signed-off-by: NLong Li <longli@microsoft.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: NRonnie Sahlberg <lsahlber@redhat.com>

When upper layer wants to umount, make it call shutdown on transport when
SMB Direct is used.
Signed-off-by: NLong Li <longli@microsoft.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: NRonnie Sahlberg <lsahlber@redhat.com>

Add function to tear down a SMB Direct connection. This is used by upper layer
to free all SMB Direct connection and transport resources.
Signed-off-by: NLong Li <longli@microsoft.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: NRonnie Sahlberg <lsahlber@redhat.com>

Do a reconnect on SMB Direct when it is used as the connection. Reconnect can
happen for many reasons and it's mostly the decision of SMB2 upper layer.
Signed-off-by: NLong Li <longli@microsoft.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Reviewed-by: NRonnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>

Add function to implement a reconnect to SMB Direct. This involves tearing down
the current connection and establishing/negotiating a new connection.
Signed-off-by: NLong Li <longli@microsoft.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: NRonnie Sahlberg <lsahlber@redhat.com>

When "rdma" is specified in the mount option, make CIFS connect to
SMB Direct.
Signed-off-by: NLong Li <longli@microsoft.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: NRonnie Sahlberg <lsahlber@redhat.com>

Prevent build errors when CIFS=y and INFINIBAND=m.

fs/cifs/smbdirect.o: In function `smbd_qp_async_error_upcall':
smbdirect.c:(.text+0x28c): undefined reference to `ib_event_msg'
fs/cifs/smbdirect.o: In function `smbd_destroy_rdma_work':
smbdirect.c:(.text+0xfde): undefined reference to `ib_drain_qp'
smbdirect.c:(.text+0xfea): undefined reference to `rdma_destroy_qp'
smbdirect.c:(.text+0x12a0): undefined reference to `ib_free_cq'
smbdirect.c:(.text+0x12ac): undefined reference to `ib_free_cq'
smbdirect.c:(.text+0x12b8): undefined reference to `ib_dealloc_pd'
smbdirect.c:(.text+0x12c4): undefined reference to `rdma_destroy_id'
fs/cifs/smbdirect.o: In function `_smbd_get_connection':
smbdirect.c:(.text+0x168c): undefined reference to `rdma_create_id'
smbdirect.c:(.text+0x1713): undefined reference to `rdma_resolve_addr'
smbdirect.c:(.text+0x1780): undefined reference to `rdma_resolve_route'
smbdirect.c:(.text+0x17e3): undefined reference to `rdma_destroy_id'
smbdirect.c:(.text+0x183d): undefined reference to `rdma_destroy_id'
smbdirect.c:(.text+0x199d): undefined reference to `ib_alloc_cq'
smbdirect.c:(.text+0x19d9): undefined reference to `ib_alloc_cq'
smbdirect.c:(.text+0x1a89): undefined reference to `rdma_create_qp'
smbdirect.c:(.text+0x1b3c): undefined reference to `rdma_connect'
smbdirect.c:(.text+0x2538): undefined reference to `rdma_destroy_qp'
smbdirect.c:(.text+0x2549): undefined reference to `ib_free_cq'
smbdirect.c:(.text+0x255a): undefined reference to `ib_free_cq'
smbdirect.c:(.text+0x2563): undefined reference to `ib_dealloc_pd'
smbdirect.c:(.text+0x256c): undefined reference to `rdma_destroy_id'
smbdirect.c:(.text+0x25f0): undefined reference to `__ib_alloc_pd'
smbdirect.c:(.text+0x26bb): undefined reference to `rdma_disconnect'
fs/cifs/smbdirect.o: In function `smbd_disconnect_rdma_work':
smbdirect.c:(.text+0x62): undefined reference to `rdma_disconnect'
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Cc:	Steve French <sfrench@samba.org>
Cc:	linux-cifs@vger.kernel.org
Cc:	samba-technical@lists.samba.org (moderated for non-subscribers)
Signed-off-by: NSteve French <smfrench@gmail.com>

If cifs_zap_mapping() returned an error, we would return without putting
the xid that we got earlier.  Restructure cifs_file_strict_mmap() and
cifs_file_mmap() to be more similar to each other and have a single
point of return that always puts the xid.
Signed-off-by: NMatthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
CC: Stable <stable@vger.kernel.org>

For use-configurable SMB Direct protocol values, export them to /proc/fs/cifs.
Signed-off-by: NLong Li <longli@microsoft.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Acked-by: NRonnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>

The upper layer calls this function to connect to peer through SMB Direct.
Each SMB Direct connection is based on a RDMA RC Queue Pair.
Signed-off-by: NLong Li <longli@microsoft.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>

Add code to implement the core functions to establish a SMB Direct connection.

1. Establish an RDMA connection to SMB server.
2. Negotiate and setup SMB Direct protocol.
3. Implement idle connection timer and credit management.

SMB Direct is enabled by setting CONFIG_CIFS_SMB_DIRECT.

Add to Makefile to enable building SMB Direct.
Signed-off-by: NLong Li <longli@microsoft.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>

To prepare for protocol implementation, add constants and user-configurable
values for the SMB Direct protocol.
Signed-off-by: NLong Li <longli@microsoft.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Acked-by: Ronnie Sahlberg <lsahlber.redhat.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.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: NLong Li <longli@microsoft.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Acked-by: Ronnie Sahlberg <lsahlber.redhat.com>

Build SMB Direct code when this option is set.
Signed-off-by: NLong Li <longli@microsoft.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Acked-by: Ronnie Sahlberg <lsahlber.redhat.com>

This patch is for preparing upper layer for doing SMB read via RDMA write.

When we assemble the SMB read packet header, we need to know the I/O layout
if this request is to use a RDMA write. rdata has all the information we need
for memory registration. Add rdata to smb2_new_read_req.
Signed-off-by: NLong Li <longli@microsoft.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Acked-by: Ronnie Sahlberg <lsahlber.redhat.com>

In both functions, use an array of 8 (arbitrary but should be big enough
for all current uses) iov and avoid having to kmalloc the array
for the common case.

If 8 is too small, then fall back to the original behaviour and use
kmalloc/kfree.

This should not change any behaviour but should save us a tiny amount of
cpu cycles.
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>

Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Acked-by: NPavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>

Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>
Acked-by: NPavel Shilovsky <pshilov@microsoft.com>

Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Acked-by: NPavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>

Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Acked-by: NPavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>

Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Acked-by: NPavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>

Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Acked-by: NPavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>

Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Acked-by: NPavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>

Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Acked-by: NPavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>

Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Acked-by: NPavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>

Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>
Acked-by: NPavel Shilovsky <pshilov@microsoft.com>

Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Acked-by: NPavel Shilovsky <pshilov@microsoft.com>

Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Acked-by: NPavel Shilovsky <pshilov@microsoft.com>

Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Acked-by: NPavel Shilovsky <pshilov@microsoft.com>

Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Acked-by: NPavel Shilovsky <pshilov@microsoft.com>

Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Acked-by: NPavel Shilovsky <pshilov@microsoft.com>

Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Acked-by: NPavel Shilovsky <pshilov@microsoft.com>

Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

This function is similar to SendReceive2 except it does not expect
a 4 byte rfc1002 length header in the first io vector.
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

Commit bdcf0a42 ("kernel: make groups_sort calling a responsibility
group_info allocators") appears to break nfsd rootsquash in a pretty
major way.

It adds a call to groups_sort() inside the loop that copies/squashes
gids, which means the valid gids are sorted along with the following
garbage.  The net result is that the highest numbered valid gids are
replaced with any lower-valued garbage gids, possibly including 0.

We should sort only once, after filling in all the gids.

Fixes: bdcf0a42 ("kernel: make groups_sort calling a responsibility ...")
Signed-off-by: NBen Hutchings <ben.hutchings@codethink.co.uk>
Acked-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In orangefs_devreq_read, there is a loop which picks an op off the list
of pending ops.  If the loop fails to find an op, there is nothing to
read, and it returns EAGAIN.  If the op has been given up on, the loop
is restarted via a goto.  The bug is that the variable which the found
op is written to is not reinitialized, so if there are no more eligible
ops on the list, the code runs again on the already handled op.

This is triggered by interrupting a process while the op is being copied
to the client-core.  It's a fairly small window, but it's there.
Signed-off-by: NMartin Brandenburg <martin@omnibond.com>
Cc: stable@vger.kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

set_op_state_purged can delete the op.
Signed-off-by: NMartin Brandenburg <martin@omnibond.com>
Cc: stable@vger.kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

do_task_stat() accesses IP and SP of a task without bumping reference
count of a stack (which became an entity with independent lifetime at
some point).

Steps to reproduce:

    #include <stdio.h>
    #include <sys/types.h>
    #include <sys/stat.h>
    #include <fcntl.h>
    #include <sys/time.h>
    #include <sys/resource.h>
    #include <unistd.h>
    #include <sys/wait.h>

    int main(void)
    {
    	setrlimit(RLIMIT_CORE, &(struct rlimit){});

    	while (1) {
    		char buf[64];
    		char buf2[4096];
    		pid_t pid;
    		int fd;

    		pid = fork();
    		if (pid == 0) {
    			*(volatile int *)0 = 0;
    		}

    		snprintf(buf, sizeof(buf), "/proc/%u/stat", pid);
    		fd = open(buf, O_RDONLY);
    		read(fd, buf2, sizeof(buf2));
    		close(fd);

    		waitpid(pid, NULL, 0);
    	}
    	return 0;
    }

    BUG: unable to handle kernel paging request at 0000000000003fd8
    IP: do_task_stat+0x8b4/0xaf0
    PGD 800000003d73e067 P4D 800000003d73e067 PUD 3d558067 PMD 0
    Oops: 0000 [#1] PREEMPT SMP PTI
    CPU: 0 PID: 1417 Comm: a.out Not tainted 4.15.0-rc8-dirty #2
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1.fc27 04/01/2014
    RIP: 0010:do_task_stat+0x8b4/0xaf0
    Call Trace:
     proc_single_show+0x43/0x70
     seq_read+0xe6/0x3b0
     __vfs_read+0x1e/0x120
     vfs_read+0x84/0x110
     SyS_read+0x3d/0xa0
     entry_SYSCALL_64_fastpath+0x13/0x6c
    RIP: 0033:0x7f4d7928cba0
    RSP: 002b:00007ffddb245158 EFLAGS: 00000246
    Code: 03 b7 a0 01 00 00 4c 8b 4c 24 70 4c 8b 44 24 78 4c 89 74 24 18 e9 91 f9 ff ff f6 45 4d 02 0f 84 fd f7 ff ff 48 8b 45 40 48 89 ef <48> 8b 80 d8 3f 00 00 48 89 44 24 20 e8 9b 97 eb ff 48 89 44 24
    RIP: do_task_stat+0x8b4/0xaf0 RSP: ffffc90000607cc8
    CR2: 0000000000003fd8

John Ogness said: for my tests I added an else case to verify that the
race is hit and correctly mitigated.

Link: http://lkml.kernel.org/r/20180116175054.GA11513@avx2Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Reported-by: N"Kohli, Gaurav" <gkohli@codeaurora.org>
Tested-by: NJohn Ogness <john.ogness@linutronix.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>