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5 years agopnfs/flexfiles: Add tracepoints for detecting pnfs fallback to MDS
Trond Myklebust [Thu, 18 Jul 2019 13:32:17 +0000 (09:32 -0400)]
pnfs/flexfiles: Add tracepoints for detecting pnfs fallback to MDS

Add tracepoints to allow debugging of the event chain leading to
a pnfs fallback to doing I/O through the MDS.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agopnfs: Fix a problem where we gratuitously start doing I/O through the MDS
Trond Myklebust [Thu, 18 Jul 2019 19:33:42 +0000 (15:33 -0400)]
pnfs: Fix a problem where we gratuitously start doing I/O through the MDS

If the client has to stop in pnfs_update_layout() to wait for another
layoutget to complete, it currently exits and defaults to I/O through
the MDS if the layoutget was successful.

Fixes: ea6a75a9ca2c ("pNFS: Ensure we return the error if someone kills...")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org # v4.20+
5 years agoSUNRPC: Optimise transport balancing code
Trond Myklebust [Tue, 16 Jul 2019 17:27:23 +0000 (13:27 -0400)]
SUNRPC: Optimise transport balancing code

Moves the balancing code to avoid doing cursor changes on every search
iteration.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agoSUNRPC: Ensure the bvecs are reset when we re-encode the RPC request
Trond Myklebust [Thu, 18 Jul 2019 01:22:38 +0000 (21:22 -0400)]
SUNRPC: Ensure the bvecs are reset when we re-encode the RPC request

The bvec tracks the list of pages, so if the number of pages changes
due to a re-encode, we need to reset the bvec as well.

Fixes: ccd359b08deb ("SUNRPC: Simplify TCP receive code by switching...")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org # v4.20+
5 years agopnfs/flexfiles: Fix PTR_ERR() dereferences in ff_layout_track_ds_error
Trond Myklebust [Wed, 17 Jul 2019 17:57:44 +0000 (13:57 -0400)]
pnfs/flexfiles: Fix PTR_ERR() dereferences in ff_layout_track_ds_error

mirror->mirror_ds can be NULL if uninitialised, but can contain
a PTR_ERR() if call to GETDEVICEINFO failed.

Fixes: cbe4f330b5e0 ("pNFS/flexfiles: Fix a deadlock on LAYOUTGET")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org # 4.10+
5 years agoNFSv4: Don't use the zero stateid with layoutget
Trond Myklebust [Tue, 16 Jul 2019 19:38:28 +0000 (15:38 -0400)]
NFSv4: Don't use the zero stateid with layoutget

The NFSv4.1 protocol explicitly forbids us from using the zero stateid
together with layoutget, so when we see that nfs4_select_rw_stateid()
is unable to return a valid delegation, lock or open stateid, then
we should initiate recovery and retry.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agoSUNRPC: Fix up backchannel slot table accounting
Trond Myklebust [Tue, 16 Jul 2019 17:51:29 +0000 (13:51 -0400)]
SUNRPC: Fix up backchannel slot table accounting

Add a per-transport maximum limit in the socket case, and add
helpers to allow the NFSv4 code to discover that limit.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agoSUNRPC: Fix initialisation of struct rpc_xprt_switch
Trond Myklebust [Thu, 18 Jul 2019 05:10:51 +0000 (01:10 -0400)]
SUNRPC: Fix initialisation of struct rpc_xprt_switch

Ensure that we do initialise the fields xps_nactive, xps_queuelen
and xps_net.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agoSUNRPC: Skip zero-refcount transports
Trond Myklebust [Tue, 16 Jul 2019 11:07:28 +0000 (07:07 -0400)]
SUNRPC: Skip zero-refcount transports

When looking for the next transport to use for an RPC call, skip those
that are in the process of being destroyed and that have a zero refcount.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agoSUNRPC: Replace division by multiplication in calculation of queue length
Trond Myklebust [Mon, 15 Jul 2019 19:12:08 +0000 (15:12 -0400)]
SUNRPC: Replace division by multiplication in calculation of queue length

When checking whether or not a particular xprt queue length is shorter
than the average queue length for all xprts, prefer to use multiplication
rather than division for performance reasons.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agoNFSv4: Validate the stateid before applying it to state recovery
Trond Myklebust [Thu, 11 Jul 2019 23:02:18 +0000 (19:02 -0400)]
NFSv4: Validate the stateid before applying it to state recovery

If the stateid is the zero or invalid stateid, then it is pointless
to attempt to use it for recovery. In that case, try to fall back
to using the open state stateid, or just doing a general recovery
of all state on a given inode.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agonfs4.0: Refetch lease_time after clientid update
Donald Buczek [Sun, 7 Jul 2019 19:26:10 +0000 (21:26 +0200)]
nfs4.0: Refetch lease_time after clientid update

RFC 7530 requires us to refetch the lease time attribute once a new
clientID is established. This is already implemented for the
nfs4.1(+) clients by nfs41_init_clientid, which calls
nfs41_finish_session_reset, which calls nfs4_setup_state_renewal.

To make nfs4_setup_state_renewal available for nfs4.0, move it
further to the top of the source file to include it regardles of
CONFIG_NFS_V4_1 and to save a forward declaration.

Call nfs4_setup_state_renewal from nfs4_init_clientid.

Signed-off-by: Donald Buczek <buczek@molgen.mpg.de>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agonfs4: Rename nfs41_setup_state_renewal
Donald Buczek [Sun, 7 Jul 2019 19:26:09 +0000 (21:26 +0200)]
nfs4: Rename nfs41_setup_state_renewal

The function nfs41_setup_state_renewal is useful to the nfs 4.0 client
as well, so rename the function to nfs4_setup_state_renewal.

Signed-off-by: Donald Buczek <buczek@molgen.mpg.de>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agonfs4: Make nfs4_proc_get_lease_time available for nfs4.0
Donald Buczek [Sun, 7 Jul 2019 19:26:08 +0000 (21:26 +0200)]
nfs4: Make nfs4_proc_get_lease_time available for nfs4.0

Compile nfs4_proc_get_lease_time, enc_get_lease_time and
dec_get_lease_time for nfs4.0. Use nfs4_sequence_done instead of
nfs41_sequence_done in nfs4_proc_get_lease_time,

Signed-off-by: Donald Buczek <buczek@molgen.mpg.de>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agonfs: Fix copy-and-paste error in debug message
Donald Buczek [Sun, 7 Jul 2019 19:26:07 +0000 (21:26 +0200)]
nfs: Fix copy-and-paste error in debug message

The debug message of decode_attr_lease_time incorrectly
says "file size". Fix it to "lease time".

Signed-off-by: Donald Buczek <buczek@molgen.mpg.de>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agoNFS: Replace 16 seq_printf() calls by seq_puts()
Markus Elfring [Wed, 3 Jul 2019 13:50:37 +0000 (15:50 +0200)]
NFS: Replace 16 seq_printf() calls by seq_puts()

Some strings should be put into a sequence.
Thus use the corresponding function “seq_puts”.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agoNFS: Use seq_putc() in nfs_show_stats()
Markus Elfring [Wed, 3 Jul 2019 13:33:09 +0000 (15:33 +0200)]
NFS: Use seq_putc() in nfs_show_stats()

A single character (line break) should be put into a sequence.
Thus use the corresponding function “seq_putc”.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agoRevert "NFS: readdirplus optimization by cache mechanism" (memleak)
Max Kellermann [Fri, 12 Jul 2019 14:18:06 +0000 (16:18 +0200)]
Revert "NFS: readdirplus optimization by cache mechanism" (memleak)

This reverts commit b409bd8c5133beacec5a36d3d02fce73bf8be33d.

That commit caused a severe memory leak in nfs_readdir_make_qstr().

When listing a directory with more than 100 files (this is how many
struct nfs_cache_array_entry elements fit in one 4kB page), all
allocated file name strings past those 100 leak.

The root of the leakage is that those string pointers are managed in
pages which are never linked into the page cache.

fs/nfs/dir.c puts pages into the page cache by calling
read_cache_page(); the callback function nfs_readdir_filler() will
then fill the given page struct which was passed to it, which is
already linked in the page cache (by do_read_cache_page() calling
add_to_page_cache_lru()).

Commit b409bd8c5133 added another (local) array of allocated pages, to
be filled with more data, instead of discarding excess items received
from the NFS server.  Those additional pages can be used by the next
nfs_readdir_filler() call (from within the same nfs_readdir() call).

The leak happens when some of those additional pages are never used
(copied to the page cache using copy_highpage()).  The pages will be
freed by nfs_readdir_free_pages(), but their contents will not.  The
commit did not invoke nfs_readdir_clear_array() (and doing so would
have been dangerous, because it did not track which of those pages
were already copied to the page cache, risking double free bugs).

How to reproduce the leak:

- Use a kernel with CONFIG_SLUB_DEBUG_ON.

- Create a directory on a NFS mount with more than 100 files with
  names long enough to use the "kmalloc-32" slab (so we can easily
  look up the allocation counts):

  for i in `seq 110`; do touch ${i}_0123456789abcdef; done

- Drop all caches:

  echo 3 >/proc/sys/vm/drop_caches

- Check the allocation counter:

  grep nfs_readdir /sys/kernel/slab/kmalloc-32/alloc_calls
  30564391 nfs_readdir_add_to_array+0x73/0xd0 age=534558/4791307/6540952 pid=370-1048386 cpus=0-47 nodes=0-1

- Request a directory listing and check the allocation counters again:

  ls
  [...]
  grep nfs_readdir /sys/kernel/slab/kmalloc-32/alloc_calls
  30564511 nfs_readdir_add_to_array+0x73/0xd0 age=207/4792999/6542663 pid=370-1048386 cpus=0-47 nodes=0-1

There are now 120 new allocations.

- Drop all caches and check the counters again:

  echo 3 >/proc/sys/vm/drop_caches
  grep nfs_readdir /sys/kernel/slab/kmalloc-32/alloc_calls
  30564401 nfs_readdir_add_to_array+0x73/0xd0 age=735/4793524/6543176 pid=370-1048386 cpus=0-47 nodes=0-1

110 allocations are gone, but 10 have leaked and will never be freed.

Unhelpfully, those allocations are explicitly excluded from KMEMLEAK,
that's why my initial attempts with KMEMLEAK were not successful:

/*
 * Avoid a kmemleak false positive. The pointer to the name is stored
 * in a page cache page which kmemleak does not scan.
 */
kmemleak_not_leak(string->name);

It would be possible to solve this bug without reverting the whole
commit:

- keep track of which pages were not used, and call
  nfs_readdir_clear_array() on them, or
- manually link those pages into the page cache

But for now I have decided to just revert the commit, because the real
fix would require complex considerations, risking more dangerous
(crash) bugs, which may seem unsuitable for the stable branches.

Signed-off-by: Max Kellermann <mk@cm4all.com>
Cc: stable@vger.kernel.org # v5.1+
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agoSUNRPC: Fix transport accounting when caller specifies an rpc_xprt
Trond Myklebust [Thu, 11 Jul 2019 20:33:12 +0000 (16:33 -0400)]
SUNRPC: Fix transport accounting when caller specifies an rpc_xprt

Ensure that we do the required accounting for the round robin queue
when the caller to rpc_init_task() has passed in a transport to be
used.

Reported-by: Olga Kornievskaia <aglo@umich.edu>
Reported-by: Neil Brown <neilb@suse.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agoMerge tag 'nfs-rdma-for-5.3-1' of git://git.linux-nfs.org/projects/anna/linux-nfs
Trond Myklebust [Thu, 11 Jul 2019 20:52:47 +0000 (16:52 -0400)]
Merge tag 'nfs-rdma-for-5.3-1' of git://git.linux-nfs.org/projects/anna/linux-nfs

NFSoRDMA client updates for 5.3

New features:
- Add a way to place MRs back on the free list
- Reduce context switching
- Add new trace events

Bugfixes and cleanups:
- Fix a BUG when tracing is enabled with NFSv4.1
- Fix a use-after-free in rpcrdma_post_recvs
- Replace use of xdr_stream_pos in rpcrdma_marshal_req
- Fix occasional transport deadlock
- Fix show_nfs_errors macros, other tracing improvements
- Remove RPCRDMA_REQ_F_PENDING and fr_state
- Various simplifications and refactors

5 years agoNFS: Record task, client ID, and XID in xdr_status trace points
Chuck Lever [Wed, 19 Jun 2019 14:34:09 +0000 (10:34 -0400)]
NFS: Record task, client ID, and XID in xdr_status trace points

When triggering an nfs_xdr_status trace point, record the task ID
and XID of the failing RPC to better pinpoint the problem.

This feels like a bit of a layering violation.

Suggested-by: Trond Myklebust <trondmy@hammerspace.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
5 years agoNFS: Update symbolic flags displayed by trace events
Chuck Lever [Wed, 19 Jun 2019 14:34:03 +0000 (10:34 -0400)]
NFS: Update symbolic flags displayed by trace events

Add missing symbolic flag names and display flags variables in
hexadecimal to improve observability.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
5 years agoNFS: Display symbolic status code names in trace log
Chuck Lever [Wed, 19 Jun 2019 14:33:58 +0000 (10:33 -0400)]
NFS: Display symbolic status code names in trace log

For improved readability, add nfs_show_status() call-sites in the
generic NFS trace points so that the symbolic status code name is
displayed.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
5 years agoNFS: Fix show_nfs_errors macros again
Chuck Lever [Wed, 19 Jun 2019 14:33:53 +0000 (10:33 -0400)]
NFS: Fix show_nfs_errors macros again

I noticed that NFS status values stopped working again.

trace_print_symbols_seq() takes an unsigned long. Passing a negative
errno or negative NFSERR value just confuses it, and since we're
using C macros here and not static inline functions, all bets are
off due to implicit type conversion.

Straight-line the calling conventions so that error codes are stored
in the trace record as positive values in an unsigned long field,
mapped to symbolic as an unsigned long, and displayed as a negative
value, to continue to enable grepping on "error=-".

It's often the case that an error value that is positive is a byte
count but when it's negative, it's an error (e.g. nfs4_write). Fix
those cases so that the value that is eventually stored in the
error field is a positive NFS status or errno, or zero.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
5 years agoNFS4: Add a trace event to record invalid CB sequence IDs
Chuck Lever [Wed, 19 Jun 2019 14:33:47 +0000 (10:33 -0400)]
NFS4: Add a trace event to record invalid CB sequence IDs

Help debug NFSv4 callback failures.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
5 years agoxprtrdma: Modernize ops->connect
Chuck Lever [Wed, 19 Jun 2019 14:33:42 +0000 (10:33 -0400)]
xprtrdma: Modernize ops->connect

Adapt and apply changes that were made to the TCP socket connect
code. See the following commits for details on the purpose of
these changes:

Commit 6406d528d4b0 ("SUNRPC: Allow changing of the TCP timeout parameters on the fly")
Commit 4132e2ae71d9 ("SUNRPC: Limit the reconnect backoff timer to the max RPC message timeout")
Commit 91a4d6dab43e ("SUNRPC: Fix reconnection timeouts")

Some common transport code is moved to xprt.c to satisfy the code
duplication police.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
5 years agoxprtrdma: Remove rpcrdma_req::rl_buffer
Chuck Lever [Wed, 19 Jun 2019 14:33:36 +0000 (10:33 -0400)]
xprtrdma: Remove rpcrdma_req::rl_buffer

Clean up.

There is only one remaining function, rpcrdma_buffer_put(), that
uses this field. Its caller can supply a pointer to the correct
rpcrdma_buffer, enabling the removal of an 8-byte pointer field
from a frequently-allocated shared data structure.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
5 years agoxprtrdma: Refactor chunk encoding
Chuck Lever [Wed, 19 Jun 2019 14:33:31 +0000 (10:33 -0400)]
xprtrdma: Refactor chunk encoding

Clean up.

Move the "not present" case into the individual chunk encoders. This
improves code organization and readability.

The reason for the original organization was to optimize for the
case where there there are no chunks. The optimization turned out to
be inconsequential, so let's err on the side of code readability.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
5 years agoxprtrdma: Streamline rpcrdma_post_recvs
Chuck Lever [Wed, 19 Jun 2019 14:33:26 +0000 (10:33 -0400)]
xprtrdma: Streamline rpcrdma_post_recvs

rb_lock is contended between rpcrdma_buffer_create,
rpcrdma_buffer_put, and rpcrdma_post_recvs.

Commit 83fb311b6d32 ("xprtrdma: Reduce the doorbell rate (Receive)")
causes rpcrdma_post_recvs to take the rb_lock repeatedly when it
determines more Receives are needed. Streamline this code path so
it takes the lock just once in most cases to build the Receive
chain that is about to be posted.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
5 years agoxprtrdma: Simplify rpcrdma_rep_create
Chuck Lever [Wed, 19 Jun 2019 14:33:20 +0000 (10:33 -0400)]
xprtrdma: Simplify rpcrdma_rep_create

Clean up.

Commit 6ebe1df697bd ("xprtrdma: Move Receive posting to Receive
handler") reduced the number of rpcrdma_rep_create call sites to
one. After that commit, the backchannel code no longer invokes it.

Therefore the free list logic added by commit 12b9cf9ffa5a
("xprtrdma: Fix backchannel allocation of extra rpcrdma_reps") is
no longer necessary, and in fact adds some extra overhead that we
can do without.

Simply post any newly created reps. They will get added back to
the rb_recv_bufs list when they subsequently complete.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
5 years agoxprtrdma: Wake RPCs directly in rpcrdma_wc_send path
Chuck Lever [Wed, 19 Jun 2019 14:33:15 +0000 (10:33 -0400)]
xprtrdma: Wake RPCs directly in rpcrdma_wc_send path

Eliminate a context switch in the path that handles RPC wake-ups
when a Receive completion has to wait for a Send completion.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
5 years agoxprtrdma: Reduce context switching due to Local Invalidation
Chuck Lever [Wed, 19 Jun 2019 14:33:10 +0000 (10:33 -0400)]
xprtrdma: Reduce context switching due to Local Invalidation

Since commit 84a0fea29b45 ("xprtrdma: Remove support for FMR memory
registration"), FRWR is the only supported memory registration mode.

We can take advantage of the asynchronous nature of FRWR's LOCAL_INV
Work Requests to get rid of the completion wait by having the
LOCAL_INV completion handler take care of DMA unmapping MRs and
waking the upper layer RPC waiter.

This eliminates two context switches when local invalidation is
necessary. As a side benefit, we will no longer need the per-xprt
deferred completion work queue.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
5 years agoxprtrdma: Add mechanism to place MRs back on the free list
Chuck Lever [Wed, 19 Jun 2019 14:33:04 +0000 (10:33 -0400)]
xprtrdma: Add mechanism to place MRs back on the free list

When a marshal operation fails, any MRs that were already set up for
that request are recycled. Recycling releases MRs and creates new
ones, which is expensive.

Since commit 8c57f62d8349 ("xprtrdma: Chain Send to FastReg WRs")
was merged, recycling FRWRs is unnecessary. This is because before
that commit, frwr_map had already posted FAST_REG Work Requests,
so ownership of the MRs had already been passed to the NIC and thus
dealing with them had to be delayed until they completed.

Since that commit, however, FAST_REG WRs are posted at the same time
as the Send WR. This means that if marshaling fails, we are certain
the MRs are safe to simply unmap and place back on the free list
because neither the Send nor the FAST_REG WRs have been posted yet.
The kernel still has ownership of the MRs at this point.

This reduces the total number of MRs that the xprt has to create
under heavy workloads and makes the marshaling logic less brittle.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
5 years agoxprtrdma: Remove fr_state
Chuck Lever [Wed, 19 Jun 2019 14:32:59 +0000 (10:32 -0400)]
xprtrdma: Remove fr_state

Now that both the Send and Receive completions are handled in
process context, it is safe to DMA unmap and return MRs to the
free or recycle lists directly in the completion handlers.

Doing this means rpcrdma_frwr no longer needs to track the state of
each MR, meaning that a VALID or FLUSHED MR can no longer appear on
an xprt's MR free list. Thus there is no longer a need to track the
MR's registration state in rpcrdma_frwr.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
5 years agoxprtrdma: Remove the RPCRDMA_REQ_F_PENDING flag
Chuck Lever [Wed, 19 Jun 2019 14:32:54 +0000 (10:32 -0400)]
xprtrdma: Remove the RPCRDMA_REQ_F_PENDING flag

Commit cf4d900d1d42 ("xprtrdma: Use xprt_pin_rqst in
rpcrdma_reply_handler") pins incoming RPC/RDMA replies so they
can be left in the pending requests queue while they are being
processed without introducing a race between ->buf_free and the
transport's reply handler. Therefore RPCRDMA_REQ_F_PENDING is no
longer necessary.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
5 years agoxprtrdma: Fix occasional transport deadlock
Chuck Lever [Wed, 19 Jun 2019 14:32:48 +0000 (10:32 -0400)]
xprtrdma: Fix occasional transport deadlock

Under high I/O workloads, I've noticed that an RPC/RDMA transport
occasionally deadlocks (IOPS goes to zero, and doesn't recover).
Diagnosis shows that the sendctx queue is empty, but when sendctxs
are returned to the queue, the xprt_write_space wake-up never
occurs. The wake-up logic in rpcrdma_sendctx_put_locked is racy.

I noticed that both EMPTY_SCQ and XPRT_WRITE_SPACE are implemented
via an atomic bit. Just one of those is sufficient. Removing
EMPTY_SCQ in favor of the generic bit mechanism makes the deadlock
un-reproducible.

Without EMPTY_SCQ, rpcrdma_buffer::rb_flags is no longer used and
is therefore removed.

Unfortunately this patch does not apply cleanly to stable. If
needed, someone will have to port it and test it.

Fixes: 2dd2419d6bef ("xprtrdma: Wait on empty sendctx queue")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
5 years agoxprtrdma: Replace use of xdr_stream_pos in rpcrdma_marshal_req
Chuck Lever [Wed, 19 Jun 2019 14:32:43 +0000 (10:32 -0400)]
xprtrdma: Replace use of xdr_stream_pos in rpcrdma_marshal_req

This is a latent bug. xdr_stream_pos works by subtracting
xdr_stream::nwords from xdr_buf::len. But xdr_stream::nwords is not
initialized by xdr_init_encode().

It works today only because all fields in rpcrdma_req::rl_stream
are initialized to zero by rpcrdma_req_create, making the
subtraction in xdr_stream_pos always a no-op.

I found this issue via code inspection. It was introduced by commit
7ab21cbf19df ("xprtrdma: Harden chunk list encoding against send
buffer overflow"), but the code has changed enough since then that
this fix can't be automatically applied to stable.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
5 years agoSUNRPC: Fix possible autodisconnect during connect due to old last_used
Dave Wysochanski [Wed, 26 Jun 2019 20:30:24 +0000 (16:30 -0400)]
SUNRPC: Fix possible autodisconnect during connect due to old last_used

Ensure last_used is updated before calling mod_timer inside
xprt_schedule_autodisconnect.  This avoids a possible xprt_autoclose
firing immediately after a successful connect when xprt_unlock_connect
calls xprt_schedule_autodisconnect with an old value of last_used.

Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agoSUNRPC: Drop redundant CONFIG_ from CONFIG_SUNRPC_DISABLE_INSECURE_ENCTYPES
Anna Schumaker [Wed, 19 Jun 2019 21:24:10 +0000 (17:24 -0400)]
SUNRPC: Drop redundant CONFIG_ from CONFIG_SUNRPC_DISABLE_INSECURE_ENCTYPES

The "CONFIG_" portion is added automatically, so this was being expanded
into "CONFIG_CONFIG_SUNRPC_DISABLE_INSECURE_ENCTYPES"

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agoNFS: Cleanup if nfs_match_client is interrupted
Benjamin Coddington [Tue, 11 Jun 2019 16:57:52 +0000 (12:57 -0400)]
NFS: Cleanup if nfs_match_client is interrupted

Don't bail out before cleaning up a new allocation if the wait for
searching for a matching nfs client is interrupted.  Memory leaks.

Reported-by: syzbot+7fe11b49c1cc30e3fce2@syzkaller.appspotmail.com
Fixes: d880bf69e0fe ("NFS: make nfs_match_client killable")
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agonfs: disable client side deduplication
Darrick J. Wong [Fri, 31 May 2019 21:06:05 +0000 (14:06 -0700)]
nfs: disable client side deduplication

The NFS protocol doesn't support deduplication, so turn it off again.

Fixes: 72c1e75cdbe5c ("Fix nfs4.2 return -EINVAL when do dedupe operation")
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agoNFSv4: Add lease_time and lease_expired to 'nfs4:' line of mountstats
Dave Wysochanski [Fri, 17 May 2019 21:06:41 +0000 (17:06 -0400)]
NFSv4: Add lease_time and lease_expired to 'nfs4:' line of mountstats

On the NFS client there is no low-impact way to determine the nfs4
lease time or whether the lease is expired, so add these to mountstats
with times displayed in seconds.

If the lease is not expired, display lease_expired=0. Otherwise,
display lease_expired=seconds_since_expired, similar to 'age:' line
in mountstats.

Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agoNFS: Clean up writeback code
Trond Myklebust [Tue, 11 Jun 2019 20:49:52 +0000 (16:49 -0400)]
NFS: Clean up writeback code

Now that the VM promises never to recurse back into the filesystem
layer on writeback, remove all the GFP_NOFS references etc from
the generic writeback code.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agoMerge branch 'multipath_tcp'
Trond Myklebust [Tue, 11 Jun 2019 20:53:33 +0000 (16:53 -0400)]
Merge branch 'multipath_tcp'

5 years agoMerge branch 'containers'
Trond Myklebust [Fri, 28 Jun 2019 15:10:39 +0000 (11:10 -0400)]
Merge branch 'containers'

5 years agoMerge branch 'cache_consistency'
Trond Myklebust [Tue, 11 Jun 2019 18:29:47 +0000 (14:29 -0400)]
Merge branch 'cache_consistency'

5 years agoSUNRPC: Remove warning in debugfs.c when compiling with W=1
Trond Myklebust [Thu, 30 May 2019 15:24:26 +0000 (11:24 -0400)]
SUNRPC: Remove warning in debugfs.c when compiling with W=1

Remove the following warning:

net/sunrpc/debugfs.c:13: warning: cannot understand function prototype: 'struct dentry *topdir;

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agoMerge branch 'bh-remove'
Trond Myklebust [Tue, 11 Jun 2019 18:19:07 +0000 (14:19 -0400)]
Merge branch 'bh-remove'

5 years agoSUNRPC: add links for all client xprts to debugfs
NeilBrown [Thu, 30 May 2019 00:41:28 +0000 (10:41 +1000)]
SUNRPC: add links for all client xprts to debugfs

Now that a client can have multiple xprts, we need to add
them all to debugs.
The first one is still "xprt"
Subsequent xprts are "xprt1", "xprt2", etc.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agoSUNRPC: Count ops completing with tk_status < 0
Dave Wysochanski [Thu, 23 May 2019 20:13:50 +0000 (16:13 -0400)]
SUNRPC: Count ops completing with tk_status < 0

We often see various error conditions with NFS4.x that show up with
a very high operation count all completing with tk_status < 0 in a
short period of time.  Add a count to rpc_iostats to record on a
per-op basis the ops that complete in this manner, which will
enable lower overhead diagnostics.

Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agoSUNRPC: enhance rpc_clnt_show_stats() to report on all xprts.
NeilBrown [Thu, 30 May 2019 00:41:28 +0000 (10:41 +1000)]
SUNRPC: enhance rpc_clnt_show_stats() to report on all xprts.

Now that a client can have multiple xprts, we need to
report the statistics for all of them.

Reported-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agoSUNRPC: Use proper printk specifiers for unsigned long long
Dave Wysochanski [Thu, 23 May 2019 20:13:49 +0000 (16:13 -0400)]
SUNRPC: Use proper printk specifiers for unsigned long long

Update the printk specifiers inside _print_rpc_iostats to avoid
a checkpatch warning.

Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agoSUNRPC: Move call to rpc_count_iostats before rpc_call_done
Dave Wysochanski [Thu, 23 May 2019 20:13:48 +0000 (16:13 -0400)]
SUNRPC: Move call to rpc_count_iostats before rpc_call_done

For diagnostic purposes, it would be useful to have an rpc_iostats
metric of RPCs completing with tk_status < 0.  Unfortunately,
tk_status is reset inside the rpc_call_done functions for each
operation, and the call to tally the per-op metrics comes after
rpc_call_done.  Refactor the call to rpc_count_iostat earlier in
rpc_exit_task so we can count these RPCs completing in error.

Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agoNFS: send state management on a single connection.
NeilBrown [Thu, 30 May 2019 00:41:28 +0000 (10:41 +1000)]
NFS: send state management on a single connection.

With NFSv4.1, different network connections need to be explicitly
bound to a session.  During session startup, this is not possible
so only a single connection must be used for session startup.

So add a task flag to disable the default round-robin choice of
connections (when nconnect > 1) and force the use of a single
connection.
Then use that flag on all requests for session management - for
consistence, include NFSv4.0 management (SETCLIENTID) and session
destruction

Reported-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agoNFS: Allow multiple connections to a NFSv2 or NFSv3 server
Trond Myklebust [Mon, 17 Sep 2018 17:32:02 +0000 (13:32 -0400)]
NFS: Allow multiple connections to a NFSv2 or NFSv3 server

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agoNFS: Display the "nconnect" mount option if it is set.
Trond Myklebust [Thu, 27 Apr 2017 15:40:04 +0000 (11:40 -0400)]
NFS: Display the "nconnect" mount option if it is set.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
5 years agopNFS: Allow multiple connections to the DS
Trond Myklebust [Thu, 27 Apr 2017 15:22:07 +0000 (11:22 -0400)]
pNFS: Allow multiple connections to the DS

If the user specifies -onconnect=<number> mount option, and the transport
protocol is TCP, then set up <number> connections to the pNFS data server
as well. The connections will all go to the same IP address.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
5 years agoNFSv4: Allow multiple connections to NFSv4.x (x>0) servers
Trond Myklebust [Thu, 27 Apr 2017 15:13:40 +0000 (11:13 -0400)]
NFSv4: Allow multiple connections to NFSv4.x (x>0) servers

If the user specifies the -onconn=<number> mount option, and the transport
protocol is TCP, then set up <number> connections to the server. The
connections will all go to the same IP address.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
5 years agoNFS: Add a mount option to specify number of TCP connections to use
Trond Myklebust [Thu, 27 Apr 2017 03:30:48 +0000 (23:30 -0400)]
NFS: Add a mount option to specify number of TCP connections to use

Allow the user to specify that the client should use multiple connections
to the server. For the moment, this functionality will be limited to
TCP and to NFSv4.x (x>0).

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
5 years agoSUNRPC: Allow creation of RPC clients with multiple connections
Trond Myklebust [Thu, 27 Apr 2017 12:50:51 +0000 (08:50 -0400)]
SUNRPC: Allow creation of RPC clients with multiple connections

Add an argument to struct rpc_create_args that allows the specification
of how many transport connections you want to set up to the server.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
5 years agoNFS: Add sysfs support for per-container identifier
Trond Myklebust [Wed, 30 Jan 2019 02:40:10 +0000 (21:40 -0500)]
NFS: Add sysfs support for per-container identifier

In order to identify containers to the NFS client, we add a per-net
sysfs attribute that udev can fill with the appropriate identifier.
The identifier could be a unique hostname, but in most cases it
will probably be a persisted uuid.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agoNFS: Add deferred cache invalidation for close-to-open consistency violations
Trond Myklebust [Wed, 22 May 2019 12:38:57 +0000 (08:38 -0400)]
NFS: Add deferred cache invalidation for close-to-open consistency violations

If the client detects that close-to-open cache consistency has been
violated, and that the file or directory has been changed on the
server, then do a cache invalidation when we're done working with
the file.
The reason we don't do an immediate cache invalidation is that we
want to avoid performance problems due to false positives. Also,
note that we cannot guarantee cache consistency in this situation
even if we do invalidate the cache.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agoSUNRPC: Remove the bh-safe lock requirement on the rpc_wait_queue->lock
Trond Myklebust [Thu, 2 May 2019 15:23:12 +0000 (11:23 -0400)]
SUNRPC: Remove the bh-safe lock requirement on the rpc_wait_queue->lock

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agoSUNRPC: Add basic load balancing to the transport switch
Trond Myklebust [Fri, 28 Apr 2017 14:52:42 +0000 (10:52 -0400)]
SUNRPC: Add basic load balancing to the transport switch

For now, just count the queue length. It is less accurate than counting
number of bytes queued, but easier to implement.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
5 years agoNFS: Cleanup - add nfs_clients_exit to mirror nfs_clients_init
Trond Myklebust [Wed, 6 Feb 2019 14:32:50 +0000 (09:32 -0500)]
NFS: Cleanup - add nfs_clients_exit to mirror nfs_clients_init

Add a helper to clean up the struct nfs_net when it is being destroyed.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agoNFS: Create a root NFS directory in /sys/fs/nfs
Trond Myklebust [Thu, 24 Jan 2019 21:10:46 +0000 (16:10 -0500)]
NFS: Create a root NFS directory in /sys/fs/nfs

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agoSUNRPC: Remove the bh-safe lock requirement on xprt->transport_lock
Trond Myklebust [Thu, 2 May 2019 15:21:08 +0000 (11:21 -0400)]
SUNRPC: Remove the bh-safe lock requirement on xprt->transport_lock

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agoSUNRPC: Replace direct task wakeups from softirq context
Trond Myklebust [Wed, 1 May 2019 20:28:29 +0000 (16:28 -0400)]
SUNRPC: Replace direct task wakeups from softirq context

Replace the direct task wakeups from inside a softirq context with
wakeups from a process context.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agoSUNRPC: Replace the queue timer with a delayed work function
Trond Myklebust [Wed, 1 May 2019 14:49:27 +0000 (10:49 -0400)]
SUNRPC: Replace the queue timer with a delayed work function

The queue timer function, which walks the RPC queue in order to locate
candidates for waking up is one of the current constraints against
removing the bh-safe queue spin locks. Replace it with a delayed
work queue, so that we can do the actual rpc task wake ups from an
ordinary process context.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agoNFSv4: Handle the special Linux file open access mode
Trond Myklebust [Thu, 27 Jun 2019 10:41:45 +0000 (06:41 -0400)]
NFSv4: Handle the special Linux file open access mode

According to the open() manpage, Linux reserves the access mode 3
to mean "check for read and write permission on the file and return
a file descriptor that can't be used for reading or writing."

Currently, the NFSv4 code will ask the server to open the file,
and will use an incorrect share access mode of 0. Since it has
an incorrect share access mode, the client later forgets to send
a corresponding close, meaning it can leak stateids on the server.

Fixes: a50dfb12dfc62 ("NFS: Split out NFS v4 file operations")
Cc: stable@vger.kernel.org # 3.6+
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agoNFSv4: Handle open for execute correctly
Trond Myklebust [Thu, 27 Jun 2019 10:30:48 +0000 (06:30 -0400)]
NFSv4: Handle open for execute correctly

When mapping the NFSv4 context to an open mode and access mode,
we need to treat the FMODE_EXEC flag differently. For the open
mode, FMODE_EXEC means we need read share access. For the access
mode checking, we need to verify that the user actually has
execute access.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
5 years agoMerge tag 'mips_fixes_5.2_2' of git://git.kernel.org/pub/scm/linux/kernel/git/mips...
Linus Torvalds [Sat, 6 Jul 2019 17:32:12 +0000 (10:32 -0700)]
Merge tag 'mips_fixes_5.2_2' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux

Pull MIPS fixes from Paul Burton:
 "A few more MIPS fixes:

   - Fix a silly typo in virt_addr_valid which led to completely bogus
     behavior (that happened to stop tripping up hardened usercopy
     despite being broken).

   - Fix UART parity setup on AR933x systems.

   - A build fix for non-Linux build machines.

   - Have the 'all' make target build DTBs, primarily to fit in with the
     behavior of scripts/package/builddeb.

   - Handle an execution hazard in TLB exceptions that use KScratch
     registers, which could inadvertently clobber the $1 register on
     some generally higher-end out-of-order CPUs.

   - A MAINTAINERS update to fix the path to the NAND driver for Ingenic
     systems"

* tag 'mips_fixes_5.2_2' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
  MAINTAINERS: Correct path to moved files
  MIPS: Add missing EHB in mtc0 -> mfc0 sequence.
  MIPS: have "plain" make calls build dtbs for selected platforms
  MIPS: fix build on non-linux hosts
  MIPS: ath79: fix ar933x uart parity mode
  MIPS: Fix bounds check virt_addr_valid

5 years agoMerge tag 'dmaengine-fix-5.2' of git://git.infradead.org/users/vkoul/slave-dma
Linus Torvalds [Sat, 6 Jul 2019 17:06:37 +0000 (10:06 -0700)]
Merge tag 'dmaengine-fix-5.2' of git://git.infradead.org/users/vkoul/slave-dma

Pull dmaengine fixes from Vinod Koul:

 - bam_dma fix for completed descriptor count

 - fix for imx-sdma remove BD_INTR for channel0 and use-after-free on
   probe error path

 - endian bug fix in jz4780 IRQ handler

* tag 'dmaengine-fix-5.2' of git://git.infradead.org/users/vkoul/slave-dma:
  dmaengine: qcom: bam_dma: Fix completed descriptors count
  dmaengine: imx-sdma: remove BD_INTR for channel0
  dmaengine: imx-sdma: fix use-after-free on probe error path
  dmaengine: jz4780: Fix an endian bug in IRQ handler

5 years agoMerge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Linus Torvalds [Sat, 6 Jul 2019 16:56:20 +0000 (09:56 -0700)]
Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

Pull SCSI fixes from James Bottomley:
 "Two iscsi fixes.

  One for an oops in the client which can be triggered by the server
  authentication protocol and the other in the target code which causes
  data corruption"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: iscsi: set auth_protocol back to NULL if CHAP_A value is not supported
  scsi: target/iblock: Fix overrun in WRITE SAME emulation

5 years agoMerge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Linus Torvalds [Sat, 6 Jul 2019 16:53:08 +0000 (09:53 -0700)]
Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs fixlet from Al Viro:
 "Fix bogus default y in Kconfig (VALIDATE_FS_PARSER)

  That thing should not be turned on by default, especially since it's
  not quiet in case it finds no problems. Geert has sent the obvious fix
  quite a few times, but it fell through the cracks"

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs: VALIDATE_FS_PARSER should default to n

5 years agoRevert "mm: page cache: store only head pages in i_pages"
Linus Torvalds [Sat, 6 Jul 2019 02:55:18 +0000 (19:55 -0700)]
Revert "mm: page cache: store only head pages in i_pages"

This reverts commit a8648c991cf03a5cab81d4eb1ea96ad80369097e.

Mikhail Gavrilov reports that it causes the VM_BUG_ON_PAGE() in
__delete_from_swap_cache() to trigger:

   page:ffffd6d34dff0000 refcount:1 mapcount:1 mapping:ffff97812323a689 index:0xfecec363
   anon
   flags: 0x17fffe00080034(uptodate|lru|active|swapbacked)
   raw: 0017fffe00080034 ffffd6d34c67c508 ffffd6d3504b8d48 ffff97812323a689
   raw: 00000000fecec363 0000000000000000 0000000100000000 ffff978433ace000
   page dumped because: VM_BUG_ON_PAGE(entry != page)
   page->mem_cgroup:ffff978433ace000
   ------------[ cut here ]------------
   kernel BUG at mm/swap_state.c:170!
   invalid opcode: 0000 [#1] SMP NOPTI
   CPU: 1 PID: 221 Comm: kswapd0 Not tainted 5.2.0-0.rc2.git0.1.fc31.x86_64 #1
   Hardware name: System manufacturer System Product Name/ROG STRIX X470-I GAMING, BIOS 2202 04/11/2019
   RIP: 0010:__delete_from_swap_cache+0x20d/0x240
   Code: 30 65 48 33 04 25 28 00 00 00 75 4a 48 83 c4 38 5b 5d 41 5c 41 5d 41 5e 41 5f c3 48 c7 c6 2f dc 0f 8a 48 89 c7 e8 93 1b fd ff <0f> 0b 48 c7 c6 a8 74 0f 8a e8 85 1b fd ff 0f 0b 48 c7 c6 a8 7d 0f
   RSP: 0018:ffffa982036e7980 EFLAGS: 00010046
   RAX: 0000000000000021 RBX: 0000000000000040 RCX: 0000000000000006
   RDX: 0000000000000000 RSI: 0000000000000086 RDI: ffff97843d657900
   RBP: 0000000000000001 R08: ffffa982036e7835 R09: 0000000000000535
   R10: ffff97845e21a46c R11: ffffa982036e7835 R12: ffff978426387120
   R13: 0000000000000000 R14: ffffd6d34dff0040 R15: ffffd6d34dff0000
   FS:  0000000000000000(0000) GS:ffff97843d640000(0000) knlGS:0000000000000000
   CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
   CR2: 00002cba88ef5000 CR3: 000000078a97c000 CR4: 00000000003406e0
   Call Trace:
    delete_from_swap_cache+0x46/0xa0
    try_to_free_swap+0xbc/0x110
    swap_writepage+0x13/0x70
    pageout.isra.0+0x13c/0x350
    shrink_page_list+0xc14/0xdf0
    shrink_inactive_list+0x1e5/0x3c0
    shrink_node_memcg+0x202/0x760
    shrink_node+0xe0/0x470
    balance_pgdat+0x2d1/0x510
    kswapd+0x220/0x420
    kthread+0xfb/0x130
    ret_from_fork+0x22/0x40

and it's not immediately obvious why it happens.  It's too late in the
rc cycle to do anything but revert for now.

Link: https://lore.kernel.org/lkml/CABXGCsN9mYmBD-4GaaeW_NrDu+FDXLzr_6x+XNxfmFV6QkYCDg@mail.gmail.com/
Reported-and-bisected-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Suggested-by: Jan Kara <jack@suse.cz>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Kirill Shutemov <kirill@shutemov.name>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
5 years agoMerge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Linus Torvalds [Sat, 6 Jul 2019 02:13:24 +0000 (19:13 -0700)]
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm fixes from Paolo Bonzini:
 "x86 bugfix patches and one compilation fix for ARM"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: arm64/sve: Fix vq_present() macro to yield a bool
  KVM: LAPIC: Fix pending interrupt in IRR blocked by software disable LAPIC
  KVM: nVMX: Change KVM_STATE_NESTED_EVMCS to signal vmcs12 is copied from eVMCS
  KVM: nVMX: Allow restore nested-state to enable eVMCS when vCPU in SMM
  KVM: x86: degrade WARN to pr_warn_ratelimited

5 years agoMerge tag 'mtd/fixes-for-5.2-final' of git://git.kernel.org/pub/scm/linux/kernel...
Linus Torvalds [Sat, 6 Jul 2019 02:07:57 +0000 (19:07 -0700)]
Merge tag 'mtd/fixes-for-5.2-final' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux

Pull mtf fixes from Miquel Raynal:

 - Fix the memory organization structure of a Macronix SPI-NAND chip.

 - Fix a build dependency wrongly described.

 - Fix the sunxi NAND driver for A23/A33 SoCs by (a) reverting the
   faulty commit introducing broken DMA support and (b) applying another
   commit bringing working DMA support.

* tag 'mtd/fixes-for-5.2-final' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux:
  mtd: rawnand: sunxi: Add A23/A33 DMA support with extra MBUS configuration
  Revert "mtd: rawnand: sunxi: Add A23/A33 DMA support"
  mtd: rawnand: ingenic: Fix ingenic_ecc dependency
  mtd: spinand: Fix max_bad_eraseblocks_per_lun info in memorg

5 years agoMerge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa...
Linus Torvalds [Sat, 6 Jul 2019 02:04:57 +0000 (19:04 -0700)]
Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

Pull i2c fixlet from Wolfram Sang:
 "I2C has a MAINTAINERS update which will be benfitial for developers,
  so let's add it right away"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: tegra: Add Dmitry as a reviewer

5 years agoMerge tag 'nfsd-5.2-2' of git://linux-nfs.org/~bfields/linux
Linus Torvalds [Sat, 6 Jul 2019 02:00:37 +0000 (19:00 -0700)]
Merge tag 'nfsd-5.2-2' of git://linux-nfs.org/~bfields/linux

Pull nfsd fixes from Bruce Fields:
 "Two more quick bugfixes for nfsd: fixing a regression causing mount
  failures on high-memory machines and fixing the DRC over RDMA"

* tag 'nfsd-5.2-2' of git://linux-nfs.org/~bfields/linux:
  nfsd: Fix overflow causing non-working mounts on 1 TB machines
  svcrdma: Ignore source port when computing DRC hash

5 years agomtd: rawnand: sunxi: Add A23/A33 DMA support with extra MBUS configuration
Miquel Raynal [Mon, 8 Apr 2019 07:41:46 +0000 (09:41 +0200)]
mtd: rawnand: sunxi: Add A23/A33 DMA support with extra MBUS configuration

Allwinner NAND controllers can make use of DMA to enhance the I/O
throughput thanks to ECC pipelining. DMA handling with A23/A33 NAND IP
is a bit different than with the older SoCs, hence the introduction of
a new compatible to handle:
* the differences between register offsets,
* the burst length change from 4 to minimum 8,
* manage SRAM accesses through MBUS with extra configuration.

Fixes: 359165367daf ("mtd: rawnand: sunxi: Add A23/A33 DMA support")
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
5 years agoRevert "mtd: rawnand: sunxi: Add A23/A33 DMA support"
Miquel Raynal [Fri, 5 Jul 2019 09:25:29 +0000 (11:25 +0200)]
Revert "mtd: rawnand: sunxi: Add A23/A33 DMA support"

This reverts commit 359165367dafe352ebced75eed88a16fa465f075.

The commit is wrong and its approach actually does not work. Let's
revert it in order to add the feature with a clean patch.

Fixes: 359165367daf ("mtd: rawnand: sunxi: Add A23/A33 DMA support")
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
5 years agoi2c: tegra: Add Dmitry as a reviewer
Dmitry Osipenko [Sun, 23 Jun 2019 17:46:55 +0000 (20:46 +0300)]
i2c: tegra: Add Dmitry as a reviewer

I'm contributing to Tegra's upstream development in general and happened
to review the Tegra's I2C patches for awhile because I'm actively using
upstream kernel on all of my Tegra-powered devices and initially some of
the submitted patches were getting my attention since they were causing
problems. Recently Wolfram Sang asked whether I'm interested in becoming
a reviewer for the driver and I don't mind at all.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
[wsa: ack was expressed by Thierry Reding in a mail thread]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
5 years agofs: VALIDATE_FS_PARSER should default to n
Geert Uytterhoeven [Mon, 1 Apr 2019 11:53:57 +0000 (13:53 +0200)]
fs: VALIDATE_FS_PARSER should default to n

CONFIG_VALIDATE_FS_PARSER is a debugging tool to check that the parser
tables are vaguely sane.  It was set to default to 'Y' for the moment to
catch errors in upcoming fs conversion development.

Make sure it is not enabled by default in the final release of v5.1.

Fixes: ef66c5fdf5226b19 ("vfs: Add configuration parser helpers")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
5 years agoKVM: arm64/sve: Fix vq_present() macro to yield a bool
Zhang Lei [Wed, 3 Jul 2019 17:42:50 +0000 (18:42 +0100)]
KVM: arm64/sve: Fix vq_present() macro to yield a bool

The original implementation of vq_present() relied on aggressive
inlining in order for the compiler to know that the code is
correct, due to some const-casting issues.  This was causing sparse
and clang to complain, while GCC compiled cleanly.

Commit 5dc82993abdd addressed this problem, but since vq_present()
is no longer a function, there is now no implicit casting of the
returned value to the return type (bool).

In set_sve_vls(), this uncast bit value is compared against a bool,
and so may spuriously compare as unequal when both are nonzero.  As
a result, KVM may reject valid SVE vector length configurations as
invalid, and vice versa.

Fix it by forcing the returned value to a bool.

Signed-off-by: Zhang Lei <zhang.lei@jp.fujitsu.com>
Fixes: 5dc82993abdd ("KVM: arm64: Implement vq_present() as a macro")
Signed-off-by: Dave Martin <Dave.Martin@arm.com> [commit message rewrite]
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
5 years agodmaengine: qcom: bam_dma: Fix completed descriptors count
Sricharan R [Fri, 28 Jun 2019 12:09:46 +0000 (17:39 +0530)]
dmaengine: qcom: bam_dma: Fix completed descriptors count

One space is left unused in circular FIFO to differentiate
'full' and 'empty' cases. So take that in to account while
counting for the descriptors completed.

Fixes the issue reported here,
https://lkml.org/lkml/2019/6/18/669

Cc: stable@vger.kernel.org
Reported-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
5 years agodmaengine: imx-sdma: remove BD_INTR for channel0
Robin Gong [Fri, 21 Jun 2019 08:23:06 +0000 (16:23 +0800)]
dmaengine: imx-sdma: remove BD_INTR for channel0

It is possible for an irq triggered by channel0 to be received later
after clks are disabled once firmware loaded during sdma probe. If
that happens then clearing them by writing to SDMA_H_INTR won't work
and the kernel will hang processing infinite interrupts. Actually,
don't need interrupt triggered on channel0 since it's pollling
SDMA_H_STATSTOP to know channel0 done rather than interrupt in
current code, just clear BD_INTR to disable channel0 interrupt to
avoid the above case.
This issue was brought by commit 2fc83ad0d052 ("dmaengine: imx-sdma:
ack channel 0 IRQ in the interrupt handler") which didn't take care
the above case.

Fixes: 2fc83ad0d052 ("dmaengine: imx-sdma: ack channel 0 IRQ in the interrupt handler")
Cc: stable@vger.kernel.org #5.0+
Signed-off-by: Robin Gong <yibin.gong@nxp.com>
Reported-by: Sven Van Asbroeck <thesven73@gmail.com>
Tested-by: Sven Van Asbroeck <thesven73@gmail.com>
Reviewed-by: Michael Olbrich <m.olbrich@pengutronix.de>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
5 years agodmaengine: imx-sdma: fix use-after-free on probe error path
Sven Van Asbroeck [Mon, 24 Jun 2019 14:07:31 +0000 (10:07 -0400)]
dmaengine: imx-sdma: fix use-after-free on probe error path

If probe() fails anywhere beyond the point where
sdma_get_firmware() is called, then a kernel oops may occur.

Problematic sequence of events:
1. probe() calls sdma_get_firmware(), which schedules the
   firmware callback to run when firmware becomes available,
   using the sdma instance structure as the context
2. probe() encounters an error, which deallocates the
   sdma instance structure
3. firmware becomes available, firmware callback is
   called with deallocated sdma instance structure
4. use after free - kernel oops !

Solution: only attempt to load firmware when we're certain
that probe() will succeed. This guarantees that the firmware
callback's context will remain valid.

Note that the remove() path is unaffected by this issue: the
firmware loader will increment the driver module's use count,
ensuring that the module cannot be unloaded while the
firmware callback is pending or running.

Signed-off-by: Sven Van Asbroeck <TheSven73@gmail.com>
Reviewed-by: Robin Gong <yibin.gong@nxp.com>
[vkoul: fixed braces for if condition]
Signed-off-by: Vinod Koul <vkoul@kernel.org>
5 years agodmaengine: jz4780: Fix an endian bug in IRQ handler
Dan Carpenter [Mon, 24 Jun 2019 13:49:40 +0000 (16:49 +0300)]
dmaengine: jz4780: Fix an endian bug in IRQ handler

The "pending" variable was a u32 but we cast it to an unsigned long
pointer when we do the for_each_set_bit() loop.  The problem is that on
big endian 64bit systems that results in an out of bounds read.

Fixes: a40aaab1b094 ("dmaengine: jz4780: Fix transfers being ACKed too soon")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
5 years agoMerge tag 'drm-fixes-2019-07-05-1' of git://anongit.freedesktop.org/drm/drm
Linus Torvalds [Fri, 5 Jul 2019 05:10:30 +0000 (14:10 +0900)]
Merge tag 'drm-fixes-2019-07-05-1' of git://anongit.freedesktop.org/drm/drm

Pull drm fixes from Dave Airlie:
 "I skipped last week because there wasn't much worth doing, this week
  got a few more fixes in.

  amdgpu:
   - default register value change
   - runpm regression fix
   - fan control fix

  i915:
   - fix Ironlake regression

  panfrost:
   - fix a double free

  virtio:
   - fix a locking bug

  imx:
   - crtc disable fixes"

* tag 'drm-fixes-2019-07-05-1' of git://anongit.freedesktop.org/drm/drm:
  drm/imx: only send event on crtc disable if kept disabled
  drm/imx: notify drm core before sending event during crtc disable
  drm/i915/ringbuffer: EMIT_INVALIDATE *before* switch context
  drm/amdgpu/gfx9: use reset default for PA_SC_FIFO_SIZE
  drm/amdgpu: Don't skip display settings in hwmgr_resume()
  drm/amd/powerplay: use hardware fan control if no powerplay fan table
  drm/panfrost: Fix a double-free error
  drm/etnaviv: add missing failure path to destroy suballoc
  drm/virtio: move drm_connector_update_edid_property() call

5 years agoMerge tag 'imx-drm-fixes-2019-07-04' of git://git.pengutronix.de/git/pza/linux into...
Dave Airlie [Fri, 5 Jul 2019 02:54:48 +0000 (12:54 +1000)]
Merge tag 'imx-drm-fixes-2019-07-04' of git://git.pengutronix.de/git/pza/linux into drm-fixes

drm/imx: fix stale vblank timestamp after a modeset

This series fixes stale vblank timestamps in the first event sent after
a crtc was disabled. The core now is notified via drm_crtc_vblank_off
before sending the last pending event in atomic_disable. If the crtc is
reenabled right away during to a modeset, the event is not sent at all,
as the next vblank will take care of it.

Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Philipp Zabel <p.zabel@pengutronix.de>
Link: https://patchwork.freedesktop.org/patch/msgid/1562237119.6641.16.camel@pengutronix.de
5 years agoMerge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Linus Torvalds [Fri, 5 Jul 2019 04:31:19 +0000 (13:31 +0900)]
Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6

Pull crypto fixes from Herbert Xu:
 "This fixes two memory leaks and a list corruption bug"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: user - prevent operating on larval algorithms
  crypto: cryptd - Fix skcipher instance memory leak
  lib/mpi: Fix karactx leak in mpi_powm

5 years agoMerge branch 'akpm' (patches from Andrew)
Linus Torvalds [Fri, 5 Jul 2019 02:39:56 +0000 (11:39 +0900)]
Merge branch 'akpm' (patches from Andrew)

Merge more fixes from Andrew Morton:
 "5 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  swap_readpage(): avoid blk_wake_io_task() if !synchronous
  devres: allow const resource arguments
  mm/vmscan.c: prevent useless kswapd loops
  fs/userfaultfd.c: disable irqs for fault_pending and event locks
  mm/page_alloc.c: fix regression with deferred struct page init

5 years agoMerge tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc
Linus Torvalds [Fri, 5 Jul 2019 02:35:45 +0000 (11:35 +0900)]
Merge tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc

Pull ARM SoC fixes from Olof Johansson:
 "Likely our final small batch of fixes for 5.2:

   - Some fixes for USB on davinci, regressions were due to the recent
     conversion of the OCHI driver to use GPIO regulators

   - A fixup of kconfig dependencies for a TI irq controller

   - A switch of armada-38x to avoid dropped characters on uart, caused
     by switch of base inherited platform description earlier this year"

* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc:
  ARM: davinci: da830-evm: fix GPIO lookup for OHCI
  ARM: davinci: omapl138-hawk: add missing regulator constraints for OHCI
  ARM: davinci: da830-evm: add missing regulator constraints for OHCI
  soc: ti: fix irq-ti-sci link error
  ARM: dts: armada-xp-98dx3236: Switch to armada-38x-uart serial node

5 years agoMerge tag 'dax-fix-5.2-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm...
Linus Torvalds [Fri, 5 Jul 2019 02:32:11 +0000 (11:32 +0900)]
Merge tag 'dax-fix-5.2-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull dax fix from Dan Williams:
 "A single dax fix that has been soaking awaiting other fixes under
  discussion to join it. As it is getting late in the cycle lets proceed
  with this fix and save follow-on changes for post-v5.3-rc1.

   - Fix xarray entry association for mixed mappings"

* tag 'dax-fix-5.2-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  dax: Fix xarray entry association for mixed mappings

5 years agoMerge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Linus Torvalds [Fri, 5 Jul 2019 02:21:36 +0000 (11:21 +0900)]
Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull do_move_mount() fix from Al Viro:
 "Regression fix"

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  vfs: move_mount: reject moving kernel internal mounts

5 years agoswap_readpage(): avoid blk_wake_io_task() if !synchronous
Oleg Nesterov [Thu, 4 Jul 2019 22:14:49 +0000 (15:14 -0700)]
swap_readpage(): avoid blk_wake_io_task() if !synchronous

swap_readpage() sets waiter = bio->bi_private even if synchronous = F,
this means that the caller can get the spurious wakeup after return.

This can be fatal if blk_wake_io_task() does
set_current_state(TASK_RUNNING) after the caller does
set_special_state(), in the worst case the kernel can crash in
do_task_dead().

Link: http://lkml.kernel.org/r/20190704160301.GA5956@redhat.com
Fixes: f8cdecabae14b08 ("block: add polled wakeup task helper")
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Qian Cai <cai@lca.pw>
Acked-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
5 years agodevres: allow const resource arguments
Arnd Bergmann [Thu, 4 Jul 2019 22:14:45 +0000 (15:14 -0700)]
devres: allow const resource arguments

devm_ioremap_resource() does not currently take 'const' arguments, which
results in a warning from the first driver trying to do it anyway:

  drivers/gpio/gpio-amd-fch.c: In function 'amd_fch_gpio_probe':
  drivers/gpio/gpio-amd-fch.c:171:49: error: passing argument 2 of 'devm_ioremap_resource' discards 'const' qualifier from pointer target type [-Werror=discarded-qualifiers]
    priv->base = devm_ioremap_resource(&pdev->dev, &amd_fch_gpio_iores);
                                                   ^~~~~~~~~~~~~~~~~~~

Change the prototype to allow it, as there is no real reason not to.

Link: http://lkml.kernel.org/r/20190628150049.1108048-1-arnd@arndb.de
Fixes: 9bb2e0452508 ("gpio: amd: Make resource struct const")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
5 years agomm/vmscan.c: prevent useless kswapd loops
Shakeel Butt [Thu, 4 Jul 2019 22:14:42 +0000 (15:14 -0700)]
mm/vmscan.c: prevent useless kswapd loops

In production we have noticed hard lockups on large machines running
large jobs due to kswaps hoarding lru lock within isolate_lru_pages when
sc->reclaim_idx is 0 which is a small zone.  The lru was couple hundred
GiBs and the condition (page_zonenum(page) > sc->reclaim_idx) in
isolate_lru_pages() was basically skipping GiBs of pages while holding
the LRU spinlock with interrupt disabled.

On further inspection, it seems like there are two issues:

(1) If kswapd on the return from balance_pgdat() could not sleep (i.e.
    node is still unbalanced), the classzone_idx is unintentionally set
    to 0 and the whole reclaim cycle of kswapd will try to reclaim only
    the lowest and smallest zone while traversing the whole memory.

(2) Fundamentally isolate_lru_pages() is really bad when the
    allocation has woken kswapd for a smaller zone on a very large machine
    running very large jobs.  It can hoard the LRU spinlock while skipping
    over 100s of GiBs of pages.

This patch only fixes (1).  (2) needs a more fundamental solution.  To
fix (1), in the kswapd context, if pgdat->kswapd_classzone_idx is
invalid use the classzone_idx of the previous kswapd loop otherwise use
the one the waker has requested.

Link: http://lkml.kernel.org/r/20190701201847.251028-1-shakeelb@google.com
Fixes: c70935eb5c59 ("mm, vmscan: prevent kswapd sleeping prematurely due to mismatched classzone_idx")
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Yang Shi <yang.shi@linux.alibaba.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
5 years agofs/userfaultfd.c: disable irqs for fault_pending and event locks
Eric Biggers [Thu, 4 Jul 2019 22:14:39 +0000 (15:14 -0700)]
fs/userfaultfd.c: disable irqs for fault_pending and event locks

When IOCB_CMD_POLL is used on a userfaultfd, aio_poll() disables IRQs
and takes kioctx::ctx_lock, then userfaultfd_ctx::fd_wqh.lock.

This may have to wait for userfaultfd_ctx::fd_wqh.lock to be released by
userfaultfd_ctx_read(), which in turn can be waiting for
userfaultfd_ctx::fault_pending_wqh.lock or
userfaultfd_ctx::event_wqh.lock.

But elsewhere the fault_pending_wqh and event_wqh locks are taken with
IRQs enabled.  Since the IRQ handler may take kioctx::ctx_lock, lockdep
reports that a deadlock is possible.

Fix it by always disabling IRQs when taking the fault_pending_wqh and
event_wqh locks.

Commit ccba82498630 ("userfaultfd: disable irqs when taking the
waitqueue lock") didn't fix this because it only accounted for the
fd_wqh lock, not the other locks nested inside it.

Link: http://lkml.kernel.org/r/20190627075004.21259-1-ebiggers@kernel.org
Fixes: e433c8c716fe ("aio: implement IOCB_CMD_POLL")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reported-by: syzbot+fab6de82892b6b9c6191@syzkaller.appspotmail.com
Reported-by: syzbot+53c0b767f7ca0dc0c451@syzkaller.appspotmail.com
Reported-by: syzbot+a3accb352f9c22041cfa@syzkaller.appspotmail.com
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org> [4.19+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>