Replace is_power_of_2 with the helper that is self-documenting and
remove the open coded call in alloc_profile_is_valid.
Signed-off-by: David Sterba <dsterba@suse.com>

As is_power_of_two takes unsigned long, it's not safe on 32bit
architectures, but we could pass any u64 value in seveal places. Add a
separate helper and also an alias that better expresses the purpose for
which the helper is used.
Signed-off-by: David Sterba <dsterba@suse.com>

When balance reduces the number of copies of metadata, it reduces the
redundancy, use the term redundancy instead of integrity.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

The function belongs to the family of locking functions, so move it
there. The 'noinline' keyword is dropped as it's now an exported
function that does not need it.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>

The function belongs to the family of locking functions, so move it
there. The 'noinline' keyword is dropped as it's now an exported
function that does not need it.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>

The function btrfs_assert_tree_locked is used outside of the locking
code so it is exported, however we can make it static inine as it's
fairly trivial.

This is the only locking assertion used in release builds, inlining
improves the text size by 174 bytes and reduces stack consumption in the
callers.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>

I've noticed that none of the btrfs_assert_*lock* debugging helpers is
inlined, despite they're short and mostly a value update. Making them
inline shaves 67 from the text size, reduces stack consumption and
perhaps also slightly improves the performance due to avoiding
unnecessary calls.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Commit ac0c7cf8 ("btrfs: fix crash when tracepoint arguments are
freed by wq callbacks") added a void pointer, wtag, which is passed into
trace_btrfs_all_work_done() instead of the freed work item. This is
silly for a few reasons:

1. The freed work item still has the same address.
2. work is still in scope after it's freed, so assigning wtag doesn't
   stop anyone from using it.
3. The tracepoint has always taken a void * argument, so assigning wtag
   doesn't actually make things any more type-safe. (Note that the
   original bug in commit bc074524 ("btrfs: prefix fsid to all trace
   events") was that the void * was implicitly casted when it was passed
   to btrfs_work_owner() in the trace point itself).

Instead, let's add some clearer warnings as comments.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Commit 9e0af237 ("Btrfs: fix task hang under heavy compressed
write") worked around the issue that a recycled work item could get a
false dependency on the original work item due to how the workqueue code
guarantees non-reentrancy. It did so by giving different work functions
to different types of work.

However, the fixes in the previous few patches are more complete, as
they prevent a work item from being recycled at all (except for a tiny
window that the kernel workqueue code handles for us). This obsoletes
the previous fix, so we don't need the unique helpers for correctness.
The only other reason to keep them would be so they show up in stack
traces, but they always seem to be optimized to a tail call, so they
don't show up anyways. So, let's just get rid of the extra indirection.

While we're here, rename normal_work_helper() to the more informative
btrfs_work_helper().
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Currently, scrub_missing_raid56_worker() puts and potentially frees
sblock (which embeds the work item) and then submits a bio through
scrub_wr_submit(). This is another potential instance of the bug in
"btrfs: don't prematurely free work in run_ordered_work()". Fix it by
dropping the reference after we submit the bio.
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Currently, reada_start_machine_worker() frees the reada_machine_work and
then calls __reada_start_machine() to do readahead. This is another
potential instance of the bug in "btrfs: don't prematurely free work in
run_ordered_work()".

There _might_ already be a deadlock here: reada_start_machine_worker()
can depend on itself through stacked filesystems (__read_start_machine()
-> reada_start_machine_dev() -> reada_tree_block_flagged() ->
read_extent_buffer_pages() -> submit_one_bio() ->
btree_submit_bio_hook() -> btrfs_map_bio() -> submit_stripe_bio() ->
submit_bio() onto a loop device can trigger readahead on the lower
filesystem).

Either way, let's fix it by freeing the work at the end.
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Currently, end_workqueue_fn() frees the end_io_wq entry (which embeds
the work item) and then calls bio_endio(). This is another potential
instance of the bug in "btrfs: don't prematurely free work in
run_ordered_work()".

In particular, the endio call may depend on other work items. For
example, btrfs_end_dio_bio() can call btrfs_subio_endio_read() ->
__btrfs_correct_data_nocsum() -> dio_read_error() ->
submit_dio_repair_bio(), which submits a bio that is also completed
through a end_workqueue_fn() work item. However,
__btrfs_correct_data_nocsum() waits for the newly submitted bio to
complete, thus it depends on another work item.

This example currently usually works because we use different workqueue
helper functions for BTRFS_WQ_ENDIO_DATA and BTRFS_WQ_ENDIO_DIO_REPAIR.
However, it may deadlock with stacked filesystems and is fragile
overall. The proper fix is to free the work item at the very end of the
work function, so let's do that.
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

We hit the following very strange deadlock on a system with Btrfs on a
loop device backed by another Btrfs filesystem:

1. The top (loop device) filesystem queues an async_cow work item from
   cow_file_range_async(). We'll call this work X.
2. Worker thread A starts work X (normal_work_helper()).
3. Worker thread A executes the ordered work for the top filesystem
   (run_ordered_work()).
4. Worker thread A finishes the ordered work for work X and frees X
   (work->ordered_free()).
5. Worker thread A executes another ordered work and gets blocked on I/O
   to the bottom filesystem (still in run_ordered_work()).
6. Meanwhile, the bottom filesystem allocates and queues an async_cow
   work item which happens to be the recently-freed X.
7. The workqueue code sees that X is already being executed by worker
   thread A, so it schedules X to be executed _after_ worker thread A
   finishes (see the find_worker_executing_work() call in
   process_one_work()).

Now, the top filesystem is waiting for I/O on the bottom filesystem, but
the bottom filesystem is waiting for the top filesystem to finish, so we
deadlock.

This happens because we are breaking the workqueue assumption that a
work item cannot be recycled while it still depends on other work. Fix
it by waiting to free the work item until we are done with all of the
related ordered work.

P.S.:

One might ask why the workqueue code doesn't try to detect a recycled
work item. It actually does try by checking whether the work item has
the same work function (find_worker_executing_work()), but in our case
the function is the same. This is the only key that the workqueue code
has available to compare, short of adding an additional, layer-violating
"custom key". Considering that we're the only ones that have ever hit
this, we should just play by the rules.

Unfortunately, we haven't been able to create a minimal reproducer other
than our full container setup using a compress-force=zstd filesystem on
top of another compress-force=zstd filesystem.
Suggested-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Commit fc97fab0 ("btrfs: Replace fs_info->qgroup_rescan_worker
workqueue with btrfs_workqueue.") converted qgroup_rescan_work to be
initialized with btrfs_init_work(), but it left behind an unnecessary
memset(). Get rid of the memset().
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

This needs to be cleaned up in the future, but for now it belongs to the
extent-io-tree stuff since it uses the internal tree search code.
Needed to export get_state_failrec and set_state_failrec as well since
we're not going to move the actual IO part of the failrec stuff out at
this point.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

This utilizes internal stuff to the extent_io_tree, so we need to export
it before we move it.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

extent_io.c/h are huge, encompassing a bunch of different things.  The
extent_io_tree code can live on its own, so separate this out.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

We are moving extent_io_tree into it's on file, so separate out the
extent_state init stuff from extent_io_tree_init().
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

We check both extent buffer and extent state leaks in the same function,
separate these two functions out so we can move them around.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

The following comment shows up in btrfs_search_slot() with out much
sense:

	/*
	 * setup the path here so we can release it under lock
	 * contention with the cow code
	 */
	if (cow) {
		/* code touching path->lock[] is far away from here */
	}

This comment hasn't been cleaned up after the relevant code has been
removed.

The original code is introduced in commit 65b51a00
("btrfs_search_slot: reduce lock contention by cowing in two stages"):

  +
  +               /*
  +                * setup the path here so we can release it under lock
  +                * contention with the cow code
  +                */
  +               p->nodes[level] = b;
  +               if (!p->skip_locking)
  +                       p->locks[level] = 1;
  +

But in current code, we have different timing for modifying path lock,
so just remove the comment.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Similar to btrfs_search_slot() done in previous patch, make a shortcut
for the level 0 case and allow to reduce indentation for the remaining
case.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>

In btrfs_search_slot(), we something like:

	if (level != 0) {
		/* Do search inside tree nodes*/
	} else {
		/* Do search inside tree leaves */
		goto done;
	}

This caused extra indent for tree node search code.  Change it to
something like:

	if (level == 0) {
		/* Do search inside tree leaves */
		goto done'
	}
	/* Do search inside tree nodes */

So we have more space to maneuver our code, this is especially useful as
the tree nodes search code is more complex than the leaves search code.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

For INODE_REF we will check:
- Objectid (ino) against previous key
  To detect missing INODE_ITEM.

- No overflow/padding in the data payload
  Much like DIR_ITEM, but with less members to check.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

For the following items, key->objectid is inode number:
- DIR_ITEM
- DIR_INDEX
- XATTR_ITEM
- EXTENT_DATA
- INODE_REF

So in the subvolume tree, such items must have its previous item share the
same objectid, e.g.:

 (257 INODE_ITEM 0)
 (257 DIR_INDEX xxx)
 (257 DIR_ITEM xxx)
 (258 INODE_ITEM 0)
 (258 INODE_REF 0)
 (258 XATTR_ITEM 0)
 (258 EXTENT_DATA 0)

But if we have the following sequence, then there is definitely
something wrong, normally some INODE_ITEM is missing, like:

 (257 INODE_ITEM 0)
 (257 DIR_INDEX xxx)
 (257 DIR_ITEM xxx)
 (258 XATTR_ITEM 0)  <<< objecitd suddenly changed to 258
 (258 EXTENT_DATA 0)

So just by checking the previous key for above inode based key types, we
can detect a missing inode item.

For INODE_REF key type, the check will be added along with INODE_REF
checker.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

It's not used ouside of transaction.c
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

A recent patch to btrfs showed that there was at least 1 case where a
nested transaction was committed. Nested transaction in this case means
a code which has a transaction handle calls some function which in turn
obtains a copy of the same transaction handle. In such cases the correct
thing to do is for the lower callee to call btrfs_end_transaction which
contains appropriate checks so as to not commit the transaction which
will result in stale trans handler for the caller.

To catch such cases add an assert in btrfs_commit_transaction ensuring
btrfs_trans_handle::use_count is always 1.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

This is similar to 942491c9 ("xfs: fix AIM7 regression"). Apparently
our current rwsem code doesn't like doing the trylock, then lock for
real scheme. This causes extra contention on the lock and can be
measured eg. by AIM7 benchmark.  So change our read/write methods to
just do the trylock for the RWF_NOWAIT case.

Fixes: edf064e7 ("btrfs: nowait aio support")
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>

Pull iommu fixes from Joerg Roedel:

 - Fix for Intel IOMMU to correct invalidation commands when in SVA
   mode.

 - Update MAINTAINERS entry for Intel IOMMU

* tag 'iommu-fixes-v5.4-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu/vt-d: Fix QI_DEV_IOTLB_PFSID and QI_DEV_EIOTLB_PFSID macros
  MAINTAINERS: Update for INTEL IOMMU (VT-d) entry

Pull misc scheduler fixes from Ingo Molnar:

 - Fix potential deadlock under CONFIG_DEBUG_OBJECTS=y

 - PELT metrics update ordering fix

 - uclamp logic fix

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/uclamp: Fix incorrect condition
  sched/pelt: Fix update of blocked PELT ordering
  sched/core: Avoid spurious lock dependencies

Pull i2c fixes from Wolfram Sang:
 "An I2C core fix to prevent a use-after-free in a rare error path,
  and an I2C ACPI addition to work around broken HW/firmware related
  to touchscreens"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: core: fix use after free in of_i2c_notify
  i2c: acpi: Force bus speed to 400KHz if a Silead touchscreen is present

Pull crypto fix from Herbert Xu:
 "This reverts a number of changes to the khwrng thread which feeds the
  kernel random number pool from hwrng drivers. They were trying to fix
  issues with suspend-and-resume but ended up causing regressions"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  Revert "hwrng: core - Freeze khwrng thread during suspend"

This reverts commit 03a3bb7a ("hwrng: core - Freeze khwrng
thread during suspend"), ff296293 ("random: Support freezable
kthreads in add_hwgenerator_randomness()") and 59b56948 ("random:
Use wait_event_freezable() in add_hwgenerator_randomness()").

These patches introduced regressions and we need more time to
get them ready for mainline.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Pull x86 fixes from Ingo Molnar:
 "Two fixes: disable unreliable HPET on Intel Coffe Lake platforms, and
  fix a lockdep splat in the resctrl code"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/resctrl: Fix potential lockdep warning
  x86/quirks: Disable HPET on Intel Coffe Lake platforms

Pull timer fix from Ingo Molnar:
 "Fix integer truncation bug in __do_adjtimex()"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  ntp/y2038: Remove incorrect time_t truncation

Pull perf fixes from Ingo Molnar:
 "Misc fixes: a handful of AUX event handling related fixes, a Sparse
  fix and two ABI fixes"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Fix missing static inline on perf_cgroup_switch()
  perf/core: Consistently fail fork on allocation failures
  perf/aux: Disallow aux_output for kernel events
  perf/core: Reattach a misplaced comment
  perf/aux: Fix the aux_output group inheritance fix
  perf/core: Disallow uncore-cgroup events

Pull networking fixes from David Miller:

 1) Fix memory leak in xfrm_state code, from Steffen Klassert.

 2) Fix races between devlink reload operations and device
    setup/cleanup, from Jiri Pirko.

 3) Null deref in NFC code, from Stephan Gerhold.

 4) Refcount fixes in SMC, from Ursula Braun.

 5) Memory leak in slcan open error paths, from Jouni Hogander.

 6) Fix ETS bandwidth validation in hns3, from Yonglong Liu.

 7) Info leak on short USB request answers in ax88172a driver, from
    Oliver Neukum.

 8) Release mem region properly in ep93xx_eth, from Chuhong Yuan.

 9) PTP config timestamp flags validation, from Richard Cochran.

10) Dangling pointers after SKB data realloc in seg6, from Andrea Mayer.

11) Missing free_netdev() in gemini driver, from Chuhong Yuan.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (56 commits)
  ipmr: Fix skb headroom in ipmr_get_route().
  net: hns3: cleanup of stray struct hns3_link_mode_mapping
  net/smc: fix fastopen for non-blocking connect()
  rds: ib: update WR sizes when bringing up connection
  net: gemini: add missed free_netdev
  net: dsa: tag_8021q: Fix dsa_8021q_restore_pvid for an absent pvid
  seg6: fix skb transport_header after decap_and_validate()
  seg6: fix srh pointer in get_srh()
  net: stmmac: Use the correct style for SPDX License Identifier
  octeontx2-af: Use the correct style for SPDX License Identifier
  ptp: Extend the test program to check the external time stamp flags.
  mlx5: Reject requests to enable time stamping on both edges.
  igb: Reject requests that fail to enable time stamping on both edges.
  dp83640: Reject requests to enable time stamping on both edges.
  mv88e6xxx: Reject requests to enable time stamping on both edges.
  ptp: Introduce strict checking of external time stamp options.
  renesas: reject unsupported external timestamp flags
  mlx5: reject unsupported external timestamp flags
  igb: reject unsupported external timestamp flags
  dp83640: reject unsupported external timestamp flags
  ...

In route.c, inet_rtm_getroute_build_skb() creates an skb with no
headroom. This skb is then used by inet_rtm_getroute() which may pass
it to rt_fill_info() and, from there, to ipmr_get_route(). The later
might try to reuse this skb by cloning it and prepending an IPv4
header. But since the original skb has no headroom, skb_push() triggers
skb_under_panic():

skbuff: skb_under_panic: text:00000000ca46ad8a len:80 put:20 head:00000000cd28494e data:000000009366fd6b tail:0x3c end:0xec0 dev:veth0
------------[ cut here ]------------
kernel BUG at net/core/skbuff.c:108!
invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 6 PID: 587 Comm: ip Not tainted 5.4.0-rc6+ #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-2.fc30 04/01/2014
RIP: 0010:skb_panic+0xbf/0xd0
Code: 41 a2 ff 8b 4b 70 4c 8b 4d d0 48 c7 c7 20 76 f5 8b 44 8b 45 bc 48 8b 55 c0 48 8b 75 c8 41 54 41 57 41 56 41 55 e8 75 dc 7a ff <0f> 0b 0f 1f 44 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00
RSP: 0018:ffff888059ddf0b0 EFLAGS: 00010286
RAX: 0000000000000086 RBX: ffff888060a315c0 RCX: ffffffff8abe4822
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88806c9a79cc
RBP: ffff888059ddf118 R08: ffffed100d9361b1 R09: ffffed100d9361b0
R10: ffff88805c68aee3 R11: ffffed100d9361b1 R12: ffff88805d218000
R13: ffff88805c689fec R14: 000000000000003c R15: 0000000000000ec0
FS:  00007f6af184b700(0000) GS:ffff88806c980000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc8204a000 CR3: 0000000057b40006 CR4: 0000000000360ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 skb_push+0x7e/0x80
 ipmr_get_route+0x459/0x6fa
 rt_fill_info+0x692/0x9f0
 inet_rtm_getroute+0xd26/0xf20
 rtnetlink_rcv_msg+0x45d/0x630
 netlink_rcv_skb+0x1a5/0x220
 rtnetlink_rcv+0x15/0x20
 netlink_unicast+0x305/0x3a0
 netlink_sendmsg+0x575/0x730
 sock_sendmsg+0xb5/0xc0
 ___sys_sendmsg+0x497/0x4f0
 __sys_sendmsg+0xcb/0x150
 __x64_sys_sendmsg+0x48/0x50
 do_syscall_64+0xd2/0xac0
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Actually the original skb used to have enough headroom, but the
reserve_skb() call was lost with the introduction of
inet_rtm_getroute_build_skb() by commit 404eb77e ("ipv4: support
sport, dport and ip_proto in RTM_GETROUTE").

We could reserve some headroom again in inet_rtm_getroute_build_skb(),
but this function shouldn't be responsible for handling the special
case of ipmr_get_route(). Let's handle that directly in
ipmr_get_route() by calling skb_realloc_headroom() instead of
skb_clone().

Fixes: 404eb77e ("ipv4: support sport, dport and ip_proto in RTM_GETROUTE")
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch cleans-up the stray left over code. It has no
functionality impact.
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

FASTOPEN does not work with SMC-sockets. Since SMC allows fallback to
TCP native during connection start, the FASTOPEN setsockopts trigger
this fallback, if the SMC-socket is still in state SMC_INIT.
But if a FASTOPEN setsockopt is called after a non-blocking connect(),
this is broken, and fallback does not make sense.
This change complements
commit cd206360 ("net/smc: avoid fallback in case of non-blocking connect")
and fixes the syzbot reported problem "WARNING in smc_unhash_sk".

Reported-by: syzbot+8488cc4cf1c9e09b8b86@syzkaller.appspotmail.com
Fixes: e1bbdd57 ("net/smc: reduce sock_put() for fallback sockets")
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>