Use -ECANCELED to signal "stop iterating" instead of these magical
*_ITER_ABORT values, since it's duplicative.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>

xfs_trans_log_buf() takes a final argument of the last byte to
log in the buffer; b_length is in basic blocks, so this isn't
the correct last byte.  Fix it.
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

In xfs_rmap_irec_offset_unpack, we should always clear the contents of
rm_flags before we begin unpacking the encoded (ondisk) offset into the
incore rm_offset and incore rm_flags fields.  Remove the open-coded
field zeroing as this encourages api misuse.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>

Remove the return value from the functions that schedule deferred bmap
operations since they never fail and do not return status.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>

Remove the return value from the functions that schedule deferred
refcount operations since they never fail and do not return status.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>

Remove the return value from the functions that schedule deferred rmap
operations since they never fail and do not return status.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>

This function doesn't use the @state parameter, so get rid of it.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>

In xfs_bmbt_diff_two_keys, we perform a signed int64_t subtraction with
two unsigned 64-bit quantities.  If the second quantity is actually the
"maximum" key (all ones) as used in _query_all, the subtraction
effectively becomes addition of two positive numbers and the function
returns incorrect results.  Fix this with explicit comparisons of the
unsigned values.  Nobody needs this now, but the online repair patches
will need this to work properly.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>

The xfs_rmap_has_other_keys helper aborts the iteration as soon as it
has an answer.  Don't let this abort leak out to callers.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>

In xfs_ialloc_setup_geometry, it's possible for a malicious/corrupt fs
image to set an unreasonably large value for sb_inopblog which will
cause ialloc_blks to be zero.  If sb_imax_pct is also set, this results
in a division by zero error in the second do_div call.  Therefore, force
maxicount to zero if ialloc_blks is zero.

Note that the kernel metadata verifiers will catch the garbage inopblog
value and abort the fs mount long before it tries to set up the inode
geometry; this is needed to avoid a crash in xfs_db while setting up the
xfs_mount structure.

Found by fuzzing sb_inopblog to 122 in xfs/350.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NCarlos Maiolino <cmaiolino@redhat.com>

The inode block mapping scrub function does more work for btree format
extent maps than is absolutely necessary -- first it will walk the bmbt
and check all the entries, and then it will load the incore tree and
check every entry in that tree, possibly for a second time.

Simplify the code and decrease check runtime by separating the two
responsibilities.  The bmbt walk will make sure the incore extent
mappings are loaded, check the shape of the bmap btree (via xchk_btree)
and check that every bmbt record has a corresponding incore extent map;
and the incore extent map walk takes all the responsibility for checking
the mapping records and cross referencing them with other AG metadata.

This enables us to clean up some messy parameter handling and reduce
redundant code.  Rename a few functions to make the split of
responsibilities clearer.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>

Fixes gcc warning:

fs/xfs/libxfs/xfs_btree.c:4475: warning: Excess function parameter 'max_recs' description in 'xfs_btree_sblock_v5hdr_verify'
fs/xfs/libxfs/xfs_btree.c:4475: warning: Excess function parameter 'pag_max_level' description in 'xfs_btree_sblock_v5hdr_verify'

Fixes: c5ab131b ("libxfs: refactor short btree block verification")
Signed-off-by: Nzhengbin <zhengbin13@huawei.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Memory we use to submit for IO needs strict alignment to the
underlying driver contraints. Worst case, this is 512 bytes. Given
that all allocations for IO are always a power of 2 multiple of 512
bytes, the kernel heap provides natural alignment for objects of
these sizes and that suffices.

Until, of course, memory debugging of some kind is turned on (e.g.
red zones, poisoning, KASAN) and then the alignment of the heap
objects is thrown out the window. Then we get weird IO errors and
data corruption problems because drivers don't validate alignment
and do the wrong thing when passed unaligned memory buffers in bios.

TO fix this, introduce kmem_alloc_io(), which will guaranteeat least
512 byte alignment of buffers for IO, even if memory debugging
options are turned on. It is assumed that the minimum allocation
size will be 512 bytes, and that sizes will be power of 2 mulitples
of 512 bytes.

Use this everywhere we allocate buffers for IO.

This no longer fails with log recovery errors when KASAN is enabled
due to the brd driver not handling unaligned memory buffers:

# mkfs.xfs -f /dev/ram0 ; mount /dev/ram0 /mnt/test
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Needed to feed into the allocation routine to guarantee the memory
buffers we add to bios are correctly aligned to the underlying
device.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

When trying to correlate XFS kernel allocations to memory reclaim
behaviour, it is useful to know what allocations XFS is actually
attempting. This information is not directly available from
tracepoints in the generic memory allocation and reclaim
tracepoints, so these new trace points provide a high level
indication of what the XFS memory demand actually is.

There is no per-filesystem context in this code, so we just trace
the type of allocation, the size and the allocation constraints.
The kmem code also doesn't include much of the common XFS headers,
so there are a few definitions that need to be added to the trace
headers and a couple of types that need to be made common to avoid
needing to include the whole world in the kmem code.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Since no caller is using KM_NOSLEEP and no callee branches on KM_SLEEP,
we can remove KM_NOSLEEP and replace KM_SLEEP with 0.
Signed-off-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

userfaultfd_release() should clear vm_flags/vm_userfaultfd_ctx even if
mm->core_state != NULL.

Otherwise a page fault can see userfaultfd_missing() == T and use an
already freed userfaultfd_ctx.

Link: http://lkml.kernel.org/r/20190820160237.GB4983@redhat.com
Fixes: 04f5866e ("coredump: fix race condition between mmget_not_zero()/get_task_mm() and core dumping")
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Reported-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: NAndrea Arcangeli <aarcange@redhat.com>
Tested-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Benjamin Moody reported to Debian that XFS partially wedges when a chgrp
fails on account of being out of disk quota.  I ran his reproducer
script:

# adduser dummy
# adduser dummy plugdev

# dd if=/dev/zero bs=1M count=100 of=test.img
# mkfs.xfs test.img
# mount -t xfs -o gquota test.img /mnt
# mkdir -p /mnt/dummy
# chown -c dummy /mnt/dummy
# xfs_quota -xc 'limit -g bsoft=100k bhard=100k plugdev' /mnt

(and then as user dummy)

$ dd if=/dev/urandom bs=1M count=50 of=/mnt/dummy/foo
$ chgrp plugdev /mnt/dummy/foo

and saw:

================================================
WARNING: lock held when returning to user space!
5.3.0-rc5 #rc5 Tainted: G        W
------------------------------------------------
chgrp/47006 is leaving the kernel with locks still held!
1 lock held by chgrp/47006:
 #0: 000000006664ea2d (&xfs_nondir_ilock_class){++++}, at: xfs_ilock+0xd2/0x290 [xfs]

...which is clearly caused by xfs_setattr_nonsize failing to unlock the
ILOCK after the xfs_qm_vop_chown_reserve call fails.  Add the missing
unlock.

Reported-by: benjamin.moody@gmail.com
Fixes: 253f4911 ("xfs: better xfs_trans_alloc interface")
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Tested-by: NSalvatore Bonaccorso <carnil@debian.org>

The outer poll loop checks for whether we need to reschedule, and
returns to userspace if we do. However, it's possible to get stuck
in the inner loop as well, if the CPU we are running on needs to
reschedule to finish the IO work.

Add the need_resched() check in the inner loop as well. This fixes
a potential hang if the kernel is configured with
CONFIG_PREEMPT_VOLUNTARY=y.
Reported-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Tested-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

If the number of dirty pages to be written back is large,
then writeback_inodes_sb will block waiting for a long time,
causing hung task detection alarm. Therefore, we should limit
the maximum number of pages written back this time, which let
the budget be completed faster. The remaining dirty pages
tend to rely on the writeback mechanism to complete the
synchronization.

Fixes: b6e51316 ("writeback: separate starting of sync vs opportunistic writeback")
Signed-off-by: NLiu Song <liu.song11@zte.com.cn>
Signed-off-by: NRichard Weinberger <richard@nod.at>

Currently on a freshly mounted UBIFS, c->min_log_bytes is 0.
This can lead to a log overrun and make commits fail.

Recent kernels will report the following assert:
UBIFS assert failed: c->lhead_lnum != c->ltail_lnum, in fs/ubifs/log.c:412

c->min_log_bytes can have two states, 0 and c->leb_size.
It controls how much bytes of the log area are reserved for non-bud
nodes such as commit nodes.

After a commit it has to be set to c->leb_size such that we have always
enough space for a commit. While a commit runs it can be 0 to make the
remaining bytes of the log available to writers.

Having it set to 0 right after mount is wrong since no space for commits
is reserved.

Fixes: 1e51764a ("UBIFS: add new flash file system")
Reported-and-tested-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NRichard Weinberger <richard@nod.at>

We unlock after orphan_delete(), so no need to unlock
in the function too.
Reported-by: NHan Xu <han.xu@nxp.com>
Fixes: 8009ce95 ("ubifs: Don't leak orphans on memory during commit")
Signed-off-by: NRichard Weinberger <richard@nod.at>

It seems that 'yfs_RXYFSStoreOpaqueACL2' should be use in
yfs_fs_store_opaque_acl2().

Fixes: f5e45463 ("afs: Implement YFS ACL setting")
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>

The afs_lookup trace event can cause the following:

[  216.576777] BUG: kernel NULL pointer dereference, address: 000000000000023b
[  216.576803] #PF: supervisor read access in kernel mode
[  216.576813] #PF: error_code(0x0000) - not-present page
...
[  216.576913] RIP: 0010:trace_event_raw_event_afs_lookup+0x9e/0x1c0 [kafs]

If the inode from afs_do_lookup() is an error other than ENOENT, or if it
is ENOENT and afs_try_auto_mntpt() returns an error, the trace event will
try to dereference the error pointer as a valid pointer.

Use IS_ERR_OR_NULL to only pass a valid pointer for the trace, or NULL.

Ideally the trace would include the error value, but for now just avoid
the oops.

Fixes: 80548b03 ("afs: Add more tracepoints")
Signed-off-by: NMarc Dionne <marc.dionne@auristor.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Fix a leak on the cell refcount in afs_lookup_cell_rcu() due to
non-clearance of the default error in the case a NULL cell name is passed
and the workstation default cell is used.

Also put a bit at the end to make sure we don't leak a cell ref if we're
going to be returning an error.

This leak results in an assertion like the following when the kafs module is
unloaded:

	AFS: Assertion failed
	2 == 1 is false
	0x2 == 0x1 is false
	------------[ cut here ]------------
	kernel BUG at fs/afs/cell.c:770!
	...
	RIP: 0010:afs_manage_cells+0x220/0x42f [kafs]
	...
	 process_one_work+0x4c2/0x82c
	 ? pool_mayday_timeout+0x1e1/0x1e1
	 ? do_raw_spin_lock+0x134/0x175
	 worker_thread+0x336/0x4a6
	 ? rescuer_thread+0x4af/0x4af
	 kthread+0x1de/0x1ee
	 ? kthread_park+0xd4/0xd4
	 ret_from_fork+0x24/0x30

Fixes: 989782dc ("afs: Overhaul cell database management")
Signed-off-by: NDavid Howells <dhowells@redhat.com>

When ceph_mdsc_do_request returns an error, we can't assume that the
filelock_reply pointer will be set. Only try to fetch fields out of
the r_reply_info when it returns success.

Cc: stable@vger.kernel.org
Reported-by: NHector Martin <hector@marcansoft.com>
Signed-off-by: NJeff Layton <jlayton@kernel.org>
Reviewed-by: N"Yan, Zheng" <zyan@redhat.com>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

clear_page_dirty_for_io(page) before mapping->a_ops->invalidatepage().
invalidatepage() clears page's private flag, if dirty flag is not
cleared, the page may cause BUG_ON failure in ceph_set_page_dirty().

Cc: stable@vger.kernel.org
Link: https://tracker.ceph.com/issues/40862Signed-off-by: NErqi Chen <chenerqi@gmail.com>
Reviewed-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

Calling ceph_buffer_put() in fill_inode() may result in freeing the
i_xattrs.blob buffer while holding the i_ceph_lock.  This can be fixed by
postponing the call until later, when the lock is released.

The following backtrace was triggered by fstests generic/070.

  BUG: sleeping function called from invalid context at mm/vmalloc.c:2283
  in_atomic(): 1, irqs_disabled(): 0, pid: 3852, name: kworker/0:4
  6 locks held by kworker/0:4/3852:
   #0: 000000004270f6bb ((wq_completion)ceph-msgr){+.+.}, at: process_one_work+0x1b8/0x5f0
   #1: 00000000eb420803 ((work_completion)(&(&con->work)->work)){+.+.}, at: process_one_work+0x1b8/0x5f0
   #2: 00000000be1c53a4 (&s->s_mutex){+.+.}, at: dispatch+0x288/0x1476
   #3: 00000000559cb958 (&mdsc->snap_rwsem){++++}, at: dispatch+0x2eb/0x1476
   #4: 000000000d5ebbae (&req->r_fill_mutex){+.+.}, at: dispatch+0x2fc/0x1476
   #5: 00000000a83d0514 (&(&ci->i_ceph_lock)->rlock){+.+.}, at: fill_inode.isra.0+0xf8/0xf70
  CPU: 0 PID: 3852 Comm: kworker/0:4 Not tainted 5.2.0+ #441
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58-prebuilt.qemu.org 04/01/2014
  Workqueue: ceph-msgr ceph_con_workfn
  Call Trace:
   dump_stack+0x67/0x90
   ___might_sleep.cold+0x9f/0xb1
   vfree+0x4b/0x60
   ceph_buffer_release+0x1b/0x60
   fill_inode.isra.0+0xa9b/0xf70
   ceph_fill_trace+0x13b/0xc70
   ? dispatch+0x2eb/0x1476
   dispatch+0x320/0x1476
   ? __mutex_unlock_slowpath+0x4d/0x2a0
   ceph_con_workfn+0xc97/0x2ec0
   ? process_one_work+0x1b8/0x5f0
   process_one_work+0x244/0x5f0
   worker_thread+0x4d/0x3e0
   kthread+0x105/0x140
   ? process_one_work+0x5f0/0x5f0
   ? kthread_park+0x90/0x90
   ret_from_fork+0x3a/0x50
Signed-off-by: NLuis Henriques <lhenriques@suse.com>
Reviewed-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

Calling ceph_buffer_put() in __ceph_build_xattrs_blob() may result in
freeing the i_xattrs.blob buffer while holding the i_ceph_lock.  This can
be fixed by having this function returning the old blob buffer and have
the callers of this function freeing it when the lock is released.

The following backtrace was triggered by fstests generic/117.

  BUG: sleeping function called from invalid context at mm/vmalloc.c:2283
  in_atomic(): 1, irqs_disabled(): 0, pid: 649, name: fsstress
  4 locks held by fsstress/649:
   #0: 00000000a7478e7e (&type->s_umount_key#19){++++}, at: iterate_supers+0x77/0xf0
   #1: 00000000f8de1423 (&(&ci->i_ceph_lock)->rlock){+.+.}, at: ceph_check_caps+0x7b/0xc60
   #2: 00000000562f2b27 (&s->s_mutex){+.+.}, at: ceph_check_caps+0x3bd/0xc60
   #3: 00000000f83ce16a (&mdsc->snap_rwsem){++++}, at: ceph_check_caps+0x3ed/0xc60
  CPU: 1 PID: 649 Comm: fsstress Not tainted 5.2.0+ #439
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58-prebuilt.qemu.org 04/01/2014
  Call Trace:
   dump_stack+0x67/0x90
   ___might_sleep.cold+0x9f/0xb1
   vfree+0x4b/0x60
   ceph_buffer_release+0x1b/0x60
   __ceph_build_xattrs_blob+0x12b/0x170
   __send_cap+0x302/0x540
   ? __lock_acquire+0x23c/0x1e40
   ? __mark_caps_flushing+0x15c/0x280
   ? _raw_spin_unlock+0x24/0x30
   ceph_check_caps+0x5f0/0xc60
   ceph_flush_dirty_caps+0x7c/0x150
   ? __ia32_sys_fdatasync+0x20/0x20
   ceph_sync_fs+0x5a/0x130
   iterate_supers+0x8f/0xf0
   ksys_sync+0x4f/0xb0
   __ia32_sys_sync+0xa/0x10
   do_syscall_64+0x50/0x1c0
   entry_SYSCALL_64_after_hwframe+0x49/0xbe
  RIP: 0033:0x7fc6409ab617
Signed-off-by: NLuis Henriques <lhenriques@suse.com>
Reviewed-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

Calling ceph_buffer_put() in __ceph_setxattr() may end up freeing the
i_xattrs.prealloc_blob buffer while holding the i_ceph_lock.  This can be
fixed by postponing the call until later, when the lock is released.

The following backtrace was triggered by fstests generic/117.

  BUG: sleeping function called from invalid context at mm/vmalloc.c:2283
  in_atomic(): 1, irqs_disabled(): 0, pid: 650, name: fsstress
  3 locks held by fsstress/650:
   #0: 00000000870a0fe8 (sb_writers#8){.+.+}, at: mnt_want_write+0x20/0x50
   #1: 00000000ba0c4c74 (&type->i_mutex_dir_key#6){++++}, at: vfs_setxattr+0x55/0xa0
   #2: 000000008dfbb3f2 (&(&ci->i_ceph_lock)->rlock){+.+.}, at: __ceph_setxattr+0x297/0x810
  CPU: 1 PID: 650 Comm: fsstress Not tainted 5.2.0+ #437
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58-prebuilt.qemu.org 04/01/2014
  Call Trace:
   dump_stack+0x67/0x90
   ___might_sleep.cold+0x9f/0xb1
   vfree+0x4b/0x60
   ceph_buffer_release+0x1b/0x60
   __ceph_setxattr+0x2b4/0x810
   __vfs_setxattr+0x66/0x80
   __vfs_setxattr_noperm+0x59/0xf0
   vfs_setxattr+0x81/0xa0
   setxattr+0x115/0x230
   ? filename_lookup+0xc9/0x140
   ? rcu_read_lock_sched_held+0x74/0x80
   ? rcu_sync_lockdep_assert+0x2e/0x60
   ? __sb_start_write+0x142/0x1a0
   ? mnt_want_write+0x20/0x50
   path_setxattr+0xba/0xd0
   __x64_sys_lsetxattr+0x24/0x30
   do_syscall_64+0x50/0x1c0
   entry_SYSCALL_64_after_hwframe+0x49/0xbe
  RIP: 0033:0x7ff23514359a
Signed-off-by: NLuis Henriques <lhenriques@suse.com>
Reviewed-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

We need to check if we have CQEs pending before starting a poll loop,
as those could be the events we will be spinning for (and hence we'll
find none). This can happen if a CQE triggers an error, or if it is
found by eg an IRQ before we get a chance to find it through polling.
Signed-off-by: NJens Axboe <axboe@kernel.dk>

If a request issue ends up being punted to async context to avoid
blocking, we can get into a situation where the original application
enters the poll loop for that very request before it has been issued.
This should not be an issue, except that the polling will hold the
io_uring uring_ctx mutex for the duration of the poll. When the async
worker has actually issued the request, it needs to acquire this mutex
to add the request to the poll issued list. Since the application
polling is already holding this mutex, the workqueue sleeps on the
mutex forever, and the application thus never gets a chance to poll for
the very request it was interested in.

Fix this by ensuring that the polling drops the uring_ctx occasionally
if it's not making any progress.
Reported-by: NJeffrey M. Birnbaum <jmbnyc@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The parens used in the while loop would result in error being assigned
the value 1 rather than the intended errno value.

This is required to return -ETXTBSY from follow on break_layout()
changes.
Signed-off-by: NIra Weiny <ira.weiny@intel.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

My recent to change to only use force_sig for a synchronous events
wound up breaking signal reception cifs and drbd.  I had overlooked
the fact that by default kthreads start out with all signals set to
SIG_IGN.  So a change I thought was safe turned out to have made it
impossible for those kernel thread to catch their signals.

Reverting the work on force_sig is a bad idea because what the code
was doing was very much a misuse of force_sig.  As the way force_sig
ultimately allowed the signal to happen was to change the signal
handler to SIG_DFL.  Which after the first signal will allow userspace
to send signals to these kernel threads.  At least for
wake_ack_receiver in drbd that does not appear actively wrong.

So correct this problem by adding allow_kernel_signal that will allow
signals whose siginfo reports they were sent by the kernel through,
but will not allow userspace generated signals, and update cifs and
drbd to call allow_kernel_signal in an appropriate place so that their
thread can receive this signal.

Fixing things this way ensures that userspace won't be able to send
signals and cause problems, that it is clear which signals the
threads are expecting to receive, and it guarantees that nothing
else in the system will be affected.

This change was partly inspired by similar cifs and drbd patches that
added allow_signal.
Reported-by: Nronnie sahlberg <ronniesahlberg@gmail.com>
Reported-by: NChristoph Böhmwalder <christoph.boehmwalder@linbit.com>
Tested-by: NChristoph Böhmwalder <christoph.boehmwalder@linbit.com>
Cc: Steve French <smfrench@gmail.com>
Cc: Philipp Reisner <philipp.reisner@linbit.com>
Cc: David Laight <David.Laight@ACULAB.COM>
Fixes: 247bc947 ("cifs: fix rmmod regression in cifs.ko caused by force_sig changes")
Fixes: 72abe3bc ("signal/cifs: Fix cifs_put_tcp_session to call send_sig instead of force_sig")
Fixes: fee10990 ("signal/drbd: Use send_sig not force_sig")
Fixes: 3cf5d076 ("signal: Remove task parameter from force_sig")
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

While trawling through the dedupe file comparison code trying to fix
page deadlocking problems, Dave Chinner noticed that the reflink code
only takes shared IOLOCK/MMAPLOCKs on the source file.  Because
page_mkwrite and directio writes do not take the EXCL versions of those
locks, this means that reflink can race with writer processes.

For pure remapping this can lead to undefined behavior and file
corruption; for dedupe this means that we cannot be sure that the
contents are identical when we decide to go ahead with the remapping.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

When dedupe wants to use the page cache to compare parts of two files
for dedupe, we must be very careful to handle locking correctly.  The
current code doesn't do this.  It must lock and unlock the page only
once if the two pages are the same, since the overlapping range check
doesn't catch this when blocksize < pagesize.  If the pages are distinct
but from the same file, we must observe page locking order and lock them
in order of increasing offset to avoid clashing with writeback locking.

Fixes: 876bec6f ("vfs: refactor clone/dedupe_file_range common functions")
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NBill O'Donnell <billodo@redhat.com>
Reviewed-by: NMatthew Wilcox (Oracle) <willy@infradead.org>

For 31-bit s390 user space, we have to pass pointer arguments through
compat_ptr() in the compat_ioctl handler.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NEric Sandeen <sandeen@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Always try the native ioctl if we don't have a compat handler.  This
removes a lot of boilerplate code as 'modern' ioctls should generally
be compat clean, and fixes the missing entries for the recently added
FS_IOC_GETFSLABEL/FS_IOC_SETFSLABEL ioctls.

Fixes: f7664b31 ("xfs: implement online get/set fs label")
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NEric Sandeen <sandeen@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

reply_cache_stats uses wrong parameter as seq file private structure and
thus causes the following kernel crash when users read
/proc/fs/nfsd/reply_cache_stats

BUG: kernel NULL pointer dereference, address: 00000000000001f9
PGD 0 P4D 0
Oops: 0000 [#3] SMP PTI
CPU: 6 PID: 1502 Comm: cat Tainted: G      D           5.3.0-rc3+ #1
Hardware name: Intel Corporation Broadwell Client platform/Basking Ridge, BIOS BDW-E2R1.86C.0118.R01.1503110618 03/11/2015
RIP: 0010:nfsd_reply_cache_stats_show+0x3b/0x2d0
Code: 41 54 49 89 f4 48 89 fe 48 c7 c7 b3 10 33 88 53 bb e8 03 00 00 e8 88 82 d1 ff bf 58 89 41 00 e8 eb c5 85 00 48 83 eb 01 75 f0 <41> 8b 94 24 f8 01 00 00 48 c7 c6 be 10 33 88 4c 89 ef bb e8 03 00
RSP: 0018:ffffaa520106fe08 EFLAGS: 00010246
RAX: 000000cfe1a77123 RBX: 0000000000000000 RCX: 0000000000291b46
RDX: 000000cf00000000 RSI: 0000000000000006 RDI: 0000000000291b28
RBP: ffffaa520106fe20 R08: 0000000000000006 R09: 000000cfe17e55dd
R10: ffffa424e47c0000 R11: 000000000000030b R12: 0000000000000001
R13: ffffa424e5697000 R14: 0000000000000001 R15: ffffa424e5697000
FS:  00007f805735f580(0000) GS:ffffa424f8f80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000000001f9 CR3: 00000000655ce005 CR4: 00000000003606e0
Call Trace:
 seq_read+0x194/0x3e0
 __vfs_read+0x1b/0x40
 vfs_read+0x95/0x140
 ksys_read+0x61/0xe0
 __x64_sys_read+0x1a/0x20
 do_syscall_64+0x4d/0x120
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f805728b861
Code: fe ff ff 50 48 8d 3d 86 b4 09 00 e8 79 e0 01 00 66 0f 1f 84 00 00 00 00 00 48 8d 05 d9 19 0d 00 8b 00 85 c0 75 13 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 57 c3 66 0f 1f 44 00 00 48 83 ec 28 48 89 54
RSP: 002b:00007ffea1ce3c38 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f805728b861
RDX: 0000000000020000 RSI: 00007f8057183000 RDI: 0000000000000003
RBP: 00007f8057183000 R08: 00007f8057182010 R09: 0000000000000000
R10: 0000000000000022 R11: 0000000000000246 R12: 0000559a60e8ff10
R13: 0000000000000003 R14: 0000000000020000 R15: 0000000000020000
Modules linked in:
CR2: 00000000000001f9
---[ end trace 01613595153f0cba ]---
RIP: 0010:nfsd_reply_cache_stats_show+0x3b/0x2d0
Code: 41 54 49 89 f4 48 89 fe 48 c7 c7 b3 10 33 88 53 bb e8 03 00 00 e8 88 82 d1 ff bf 58 89 41 00 e8 eb c5 85 00 48 83 eb 01 75 f0 <41> 8b 94 24 f8 01 00 00 48 c7 c6 be 10 33 88 4c 89 ef bb e8 03 00
RSP: 0018:ffffaa52004b3e08 EFLAGS: 00010246
RAX: 0000002bab45a7c6 RBX: 0000000000000000 RCX: 0000000000291b4c
RDX: 0000002b00000000 RSI: 0000000000000004 RDI: 0000000000291b28
RBP: ffffaa52004b3e20 R08: 0000000000000004 R09: 0000002bab1c8c7a
R10: ffffa424e5500000 R11: 00000000000002a9 R12: 0000000000000001
R13: ffffa424e4475000 R14: 0000000000000001 R15: ffffa424e4475000
FS:  00007f805735f580(0000) GS:ffffa424f8f80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000000001f9 CR3: 00000000655ce005 CR4: 00000000003606e0
Killed

Fixes: 3ba75830 ("nfsd4: drc containerization")
Signed-off-by: NHe Zhe <zhe.he@windriver.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

A process could race in an open and attempt to read one of these files
before i_private is initialized, and get a spurious error.
Reported-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>