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>

The previous fix in commit 384632e6 ("userfaultfd: non-cooperative:
fix fork use after free") corrected the refcounting in case of
UFFD_EVENT_FORK failure for the fork userfault paths.

That still didn't clear the vma->vm_userfaultfd_ctx of the vmas that
were set to point to the aborted new uffd ctx earlier in
dup_userfaultfd.

Link: http://lkml.kernel.org/r/20171223002505.593-2-aarcange@redhat.comSigned-off-by: NAndrea Arcangeli <aarcange@redhat.com>
Reported-by: Nsyzbot <syzkaller@googlegroups.com>
Reviewed-by: NMike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Eric Biggers <ebiggers3@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This is a logical revert of commit e37fdb78 ("exec: Use secureexec
for setting dumpability")

This weakens dumpability back to checking only for uid/gid changes in
current (which is useless), but userspace depends on dumpability not
being tied to secureexec.

  https://bugzilla.redhat.com/show_bug.cgi?id=1528633Reported-by: NTom Horsley <horsley1953@gmail.com>
Fixes: e37fdb78 ("exec: Use secureexec for setting dumpability")
Cc: stable@vger.kernel.org
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix some integer overflow problems if offset + count happen to be large
enough to cause an integer overflow.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

xfs_qm_init_quotainfo() does not check result of register_shrinker()
which was tagged as __must_check recently, reported by sparse.
Signed-off-by: NAliaksei Karaliou <akaraliou.dev@gmail.com>
[darrick: move xfs_qm_destroy_quotainos nearer xfs_qm_init_quotainos]
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

xfs_qm_destroy_quotainfo() does not destroy quotainfo->qi_tree_lock
while destroys quotainfo->qi_quotaofflock.
Signed-off-by: NAliaksei Karaliou <akaraliou.dev@gmail.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

refcounts have a generic implementation and an asm optimized one.  The
generic version has extra debugging to make sure that once a refcount
goes to zero, refcount_inc won't increase it.

The btrfs delayed inode code wasn't expecting this, and we're tripping
over the warnings when the generic refcounts are used.  We ended up with
this race:

Process A                                         Process B
                                                  btrfs_get_delayed_node()
						  spin_lock(root->inode_lock)
						  radix_tree_lookup()
__btrfs_release_delayed_node()
refcount_dec_and_test(&delayed_node->refs)
our refcount is now zero
						  refcount_add(2) <---
						  warning here, refcount
                                                  unchanged

spin_lock(root->inode_lock)
radix_tree_delete()

With the generic refcounts, we actually warn again when process B above
tries to release his refcount because refcount_add() turned into a
no-op.

We saw this in production on older kernels without the asm optimized
refcounts.

The fix used here is to use refcount_inc_not_zero() to detect when the
object is in the middle of being freed and return NULL.  This is almost
always the right answer anyway, since we usually end up pitching the
delayed_node if it didn't have fresh data in it.

This also changes __btrfs_release_delayed_node() to remove the extra
check for zero refcounts before radix tree deletion.
btrfs_get_delayed_node() was the only path that was allowing refcounts
to go from zero to one.

Fixes: 6de5f18e ("btrfs: fix refcount_t usage when deleting btrfs_delayed_node")
CC: <stable@vger.kernel.org> # 4.12+
Signed-off-by: NChris Mason <clm@fb.com>
Reviewed-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Commit e0ae9994 ("btrfs: preallocate device flush bio") reworked
the way the flush bio is allocated and used. Concretely it allocates
the bio in __alloc_device and then re-uses it multiple times with a
very simple endio routine that just calls complete() without consuming
a reference. Allocated bios by default come with a ref count of 1,
which is then consumed by the endio routine (or not, in which case they
should be bio_put by the caller). The way the impleementation works now
is that the flush bio has a refcount of 2 and we only ever bio_put it
once, leaving it to hang indefinitely. Fix this by removing the extra
bio_get in __alloc_device.

Fixes: e0ae9994 ("btrfs: preallocate device flush bio")
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NLiu Bo <bo.li.liu@oracle.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>