In lieu of dprintks or tracepoints in each individual transport
implementation, introduce tracepoints in the generic part of the RPC
layer. These typically fire for connection lifetime events, so
shouldn't contribute a lot of noise.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

Capture transport creation failures.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

Clean up: The xprt=%p was meant to distinguish events from different
transports, but the addr=%s does that just as well and does not
expose kernel memory addresses.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

Failure to accept a connection is typically due to a problem
specific to a transport type. Also, ->xpo_accept returns NULL
on error rather than reporting a specific problem.

So, add failure-specific tracepoints in svc_rdma_accept().
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

Clean up: Use a consistent naming convention so that these trace
points can be enabled quickly via a glob.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

Clean up: Replace a dprintk call site.

This is the last remaining dprintk call site in svc_rdma_rw.c, so
remove dprintk infrastructure as well.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

Clean up: Replace a dprintk call site with a tracepoint.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

Clean up: Replace two dprintk call sites with a tracepoint.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

- De-duplicate code
- Rename the tracepoint with "_err" to allow enabling via glob
- Report the sg_cnt for the failing rw_ctx
- Fix a dumb signage issue
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

Use the common interface bdi_dev_name() to get device name.
Signed-off-by: NYufen Yu <yuyufen@huawei.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>

Add missing <linux/backing-dev.h> include BFQ
Signed-off-by: NJens Axboe <axboe@kernel.dk>

This change updates the improper comment for the 'size' attribute in the
tracepoint definition. Most gfx drivers pre-fault in physical pages
instead of making virtual allocations. So we drop the 'Virtual' keyword
here and leave this to the implementations.

Link: http://lkml.kernel.org/r/20200428220825.169606-1-zzyiwei@google.comSigned-off-by: NYiwei Zhang <zzyiwei@google.com>
Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>

Systemtap 4.2 is unable to correctly interpret the "u32 (*missed_ppm)[2]"
argument of the iocost_ioc_vrate_adj trace entry defined in
include/trace/events/iocost.h leading to the following error:

  /tmp/stapAcz0G0/stap_c89c58b83cea1724e26395efa9ed4939_6321_aux_6.c:78:8:
  error: expected ‘;’, ‘,’ or ‘)’ before ‘*’ token
   , u32[]* __tracepoint_arg_missed_ppm

That argument type is indeed rather complex and hard to read. Looking
at block/blk-iocost.c. It is just a 2-entry u32 array. By simplifying
the argument to a simple "u32 *missed_ppm" and adjusting the trace
entry accordingly, the compilation error was gone.

Fixes: 7caa4715 ("blkcg: implement blk-iocost")
Acked-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NWaiman Long <longman@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

It's not safe to use resources pointed to by the @send_wr of
ib_post_send() _after_ that function returns. Those resources are
typically freed by the Send completion handler, which can run before
ib_post_send() returns.

Thus the trace points currently around ib_post_send() in the
client's RPC/RDMA transport are a hazard, even when they are
disabled. Rearrange them so that they touch the Work Request only
_before_ ib_post_send() is invoked.

Fixes: ab03eff5 ("xprtrdma: Add trace points in RPC Call transmit paths")
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

free_more_memory func has been completely removed in commit bc48f001
("buffer: eliminate the need to call free_more_memory() in __getblk_slow()")

So comment and `WB_REASON_FREE_MORE_MEM` reason about free_more_memory
are no longer needed.

Fixes: bc48f001 ("buffer: eliminate the need to call free_more_memory() in __getblk_slow()")
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: NZhiqiang Liu <liuzhiqiang26@huawei.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

I hit this while testing nfsd-5.7 with kernel memory debugging
enabled on my server:

Mar 30 13:21:45 klimt kernel: BUG: unable to handle page fault for address: ffff8887e6c279a8
Mar 30 13:21:45 klimt kernel: #PF: supervisor read access in kernel mode
Mar 30 13:21:45 klimt kernel: #PF: error_code(0x0000) - not-present page
Mar 30 13:21:45 klimt kernel: PGD 3601067 P4D 3601067 PUD 87c519067 PMD 87c3e2067 PTE 800ffff8193d8060
Mar 30 13:21:45 klimt kernel: Oops: 0000 [#1] SMP DEBUG_PAGEALLOC PTI
Mar 30 13:21:45 klimt kernel: CPU: 2 PID: 1933 Comm: nfsd Not tainted 5.6.0-rc6-00040-g881e87a3c6f9 #1591
Mar 30 13:21:45 klimt kernel: Hardware name: Supermicro Super Server/X10SRL-F, BIOS 1.0c 09/09/2015
Mar 30 13:21:45 klimt kernel: RIP: 0010:svc_rdma_post_chunk_ctxt+0xab/0x284 [rpcrdma]
Mar 30 13:21:45 klimt kernel: Code: c1 83 34 02 00 00 29 d0 85 c0 7e 72 48 8b bb a0 02 00 00 48 8d 54 24 08 4c 89 e6 48 8b 07 48 8b 40 20 e8 5a 5c 2b e1 41 89 c6 <8b> 45 20 89 44 24 04 8b 05 02 e9 01 00 85 c0 7e 33 e9 5e 01 00 00
Mar 30 13:21:45 klimt kernel: RSP: 0018:ffffc90000dfbdd8 EFLAGS: 00010286
Mar 30 13:21:45 klimt kernel: RAX: 0000000000000000 RBX: ffff8887db8db400 RCX: 0000000000000030
Mar 30 13:21:45 klimt kernel: RDX: 0000000000000040 RSI: 0000000000000000 RDI: 0000000000000246
Mar 30 13:21:45 klimt kernel: RBP: ffff8887e6c27988 R08: 0000000000000000 R09: 0000000000000004
Mar 30 13:21:45 klimt kernel: R10: ffffc90000dfbdd8 R11: 00c068ef00000000 R12: ffff8887eb4e4a80
Mar 30 13:21:45 klimt kernel: R13: ffff8887db8db634 R14: 0000000000000000 R15: ffff8887fc931000
Mar 30 13:21:45 klimt kernel: FS:  0000000000000000(0000) GS:ffff88885bd00000(0000) knlGS:0000000000000000
Mar 30 13:21:45 klimt kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Mar 30 13:21:45 klimt kernel: CR2: ffff8887e6c279a8 CR3: 000000081b72e002 CR4: 00000000001606e0
Mar 30 13:21:45 klimt kernel: Call Trace:
Mar 30 13:21:45 klimt kernel: ? svc_rdma_vec_to_sg+0x7f/0x7f [rpcrdma]
Mar 30 13:21:45 klimt kernel: svc_rdma_send_write_chunk+0x59/0xce [rpcrdma]
Mar 30 13:21:45 klimt kernel: svc_rdma_sendto+0xf9/0x3ae [rpcrdma]
Mar 30 13:21:45 klimt kernel: ? nfsd_destroy+0x51/0x51 [nfsd]
Mar 30 13:21:45 klimt kernel: svc_send+0x105/0x1e3 [sunrpc]
Mar 30 13:21:45 klimt kernel: nfsd+0xf2/0x149 [nfsd]
Mar 30 13:21:45 klimt kernel: kthread+0xf6/0xfb
Mar 30 13:21:45 klimt kernel: ? kthread_queue_delayed_work+0x74/0x74
Mar 30 13:21:45 klimt kernel: ret_from_fork+0x3a/0x50
Mar 30 13:21:45 klimt kernel: Modules linked in: ocfs2_dlmfs ocfs2_stack_o2cb ocfs2_dlm ocfs2_nodemanager ocfs2_stackglue ib_umad ib_ipoib mlx4_ib sb_edac x86_pkg_temp_thermal iTCO_wdt iTCO_vendor_support coretemp kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel glue_helper crypto_simd cryptd pcspkr rpcrdma i2c_i801 rdma_ucm lpc_ich mfd_core ib_iser rdma_cm iw_cm ib_cm mei_me raid0 libiscsi mei sg scsi_transport_iscsi ioatdma wmi ipmi_si ipmi_devintf ipmi_msghandler acpi_power_meter nfsd nfs_acl lockd auth_rpcgss grace sunrpc ip_tables xfs libcrc32c mlx4_en sd_mod sr_mod cdrom mlx4_core crc32c_intel igb nvme i2c_algo_bit ahci i2c_core libahci nvme_core dca libata t10_pi qedr dm_mirror dm_region_hash dm_log dm_mod dax qede qed crc8 ib_uverbs ib_core
Mar 30 13:21:45 klimt kernel: CR2: ffff8887e6c279a8
Mar 30 13:21:45 klimt kernel: ---[ end trace 87971d2ad3429424 ]---

It's absolutely not safe to use resources pointed to by the @send_wr
argument of ib_post_send() _after_ that function returns. Those
resources are typically freed by the Send completion handler, which
can run before ib_post_send() returns.

Thus the trace points currently around ib_post_send() in the
server's RPC/RDMA transport are a hazard, even when they are
disabled. Rearrange them so that they touch the Work Request only
_before_ ib_post_send() is invoked.

Fixes: bd2abef3 ("svcrdma: Trace key RDMA API events")
Fixes: 4201c746 ("svcrdma: Introduce svc_rdma_send_ctxt")
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

Drop needless newlines from tracepoint format strings, they only add
empty lines to perf tracing output.
Signed-off-by: NTommi Rantala <tommi.t.rantala@nokia.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Don't collapse the huge PMD if there is any userfault write protected
small PTEs.  The problem is that the write protection is in small page
granularity and there's no way to keep all these write protection
information if the small pages are going to be merged into a huge PMD.

The same thing needs to be considered for swap entries and migration
entries.  So do the check as well disregarding khugepaged_max_ptes_swap.
Signed-off-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: NJerome Glisse <jglisse@redhat.com>
Reviewed-by: NMike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Bobby Powers <bobbypowers@gmail.com>
Cc: Brian Geffon <bgeffon@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Denis Plotnikov <dplotnikov@virtuozzo.com>
Cc: "Dr . David Alan Gilbert" <dgilbert@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Kirill A . Shutemov" <kirill@shutemov.name>
Cc: Martin Cracauer <cracauer@cons.org>
Cc: Marty McFadden <mcfadden8@llnl.gov>
Cc: Maya Gokhale <gokhale2@llnl.gov>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Shaohua Li <shli@fb.com>
Link: http://lkml.kernel.org/r/20200220163112.11409-12-peterx@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Some comments for MADV_FREE is revised and added to help people understand
the MADV_FREE code, especially the page flag, PG_swapbacked.  This makes
page_is_file_cache() isn't consistent with its comments.  So the function
is renamed to page_is_file_lru() to make them consistent again.  All these
are put in one patch as one logical change.
Suggested-by: NDavid Hildenbrand <david@redhat.com>
Suggested-by: NJohannes Weiner <hannes@cmpxchg.org>
Suggested-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: N"Huang, Ying" <ying.huang@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NDavid Rientjes <rientjes@google.com>
Acked-by: NMichal Hocko <mhocko@kernel.org>
Acked-by: NPankaj Gupta <pankaj.gupta.linux@gmail.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@surriel.com>
Link: http://lkml.kernel.org/r/20200317100342.2730705-1-ying.huang@intel.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "mm/vma: Use all available wrappers when possible", v2.

Apart from adding a VMA flag readable name for trace purpose, this series
does some open encoding replacements with availabe VMA specific wrappers.
This skips VM_HUGETLB check in vma_migratable() as its already being done
with another patch (https://patchwork.kernel.org/patch/11347831/) which is
yet to be merged.

This patch (of 4):

This just adds the missing readable name for VM_SYNC.
Signed-off-by: NAnshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nick Piggin <npiggin@gmail.com>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/1582520593-30704-2-git-send-email-anshuman.khandual@arm.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add zstd compress algorithm support, use "compress_algorithm=zstd"
mountoption to enable it.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Even on 64 bit kernel, the mmap failure can happen for a 32 bit task.
Virtual memory space shortage of a task on mmap is reported to userspace
as -ENOMEM.  It can be confused as physical memory shortage of overall
system.

The vm_unmapped_area can be called to by some drivers or other kernel core
system like filesystem.  In my platform, GPU driver calls to
vm_unmapped_area and the driver returns -ENOMEM even in GPU side shortage.
It can be hard to distinguish which code layer returns the -ENOMEM.

Create mmap trace file and add trace point of vm_unmapped_area.

i.e.)
277.156599: vm_unmapped_area: addr=77e0d03000 err=0 total_vm=0x17014b flags=0x1 len=0x400000 lo=0x8000 hi=0x7878c27000 mask=0x0 ofs=0x1
342.838740: vm_unmapped_area: addr=0 err=-12 total_vm=0xffb08 flags=0x0 len=0x100000 lo=0x40000000 hi=0xfffff000 mask=0x0 ofs=0x22

[akpm@linux-foundation.org: prefix address printk with 0x, per Matthew]
Signed-off-by: NJaewon Kim <jaewon31.kim@samsung.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michel Lespinasse <walken@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Link: http://lkml.kernel.org/r/20200320055823.27089-3-jaewon31.kim@samsung.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Change the rpcrdma_xprt_disconnect() function so that it no longer
waits for the DISCONNECTED event.  This prevents blocking if the
remote is unresponsive.

In rpcrdma_xprt_disconnect(), the transport's rpcrdma_ep is
detached. Upon return from rpcrdma_xprt_disconnect(), the transport
(r_xprt) is ready immediately for a new connection.

The RDMA_CM_DEVICE_REMOVAL and RDMA_CM_DISCONNECTED events are now
handled almost identically.

However, because the lifetimes of rpcrdma_xprt structures and
rpcrdma_ep structures are now independent, creating an rpcrdma_ep
needs to take a module ref count. The ep now owns most of the
hardware resources for a transport.

Also, a kref is needed to ensure that rpcrdma_ep sticks around
long enough for the cm_event_handler to finish.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

rpcrdma_cm_event_handler() is always passed an @id pointer that is
valid. However, in a subsequent patch, we won't be able to extract
an r_xprt in every case. So instead of using the r_xprt's
presentation address strings, extract them from struct rdma_cm_id.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

I eventually want to allocate rpcrdma_ep separately from struct
rpcrdma_xprt so that on occasion there can be more than one ep per
xprt.

The new struct rpcrdma_ep will contain all the fields currently in
rpcrdma_ia and in rpcrdma_ep. This is all the device and CM settings
for the connection, in addition to per-connection settings
negotiated with the remote.

Take this opportunity to rename the existing ep fields from rep_* to
re_* to disambiguate these from struct rpcrdma_rep.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Completion errors after a disconnect often occur much sooner than a
CM_DISCONNECT event. Use this to try to detect connection loss more
quickly.

Note that other kernel ULPs do take care to disconnect explicitly
when a WR is flushed.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Move rdma_cm_id creation into rpcrdma_ep_create() so that it is now
responsible for allocating all per-connection hardware resources.

With this clean-up, all three arms of the switch statement in
rpcrdma_ep_connect are exactly the same now, thus the switch can be
removed.

Because device removal behaves a little differently than
disconnection, there is a little more work to be done before
rpcrdma_ep_destroy() can release the connection's rdma_cm_id. So
it is not quite symmetrical with rpcrdma_ep_create() yet.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Two changes:
- Show the number of SG entries that were mapped. This helps debug
  DMA-related problems.
- Record the MR's resource ID instead of its memory address. This
  groups each MR with its associated rdma-tool output, and reduces
  needless exposure of memory addresses.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Trace events target_sequencer_start and target_cmd_complete
(include/trace/events/target.h) are ready to show NAA identifier, LUN ID,
and many other important command details in the system log:

TP_printk("%s -> LUN %03u %s data_length %6u  CDB %s  (TA:%s C:%02x)",

However, it's still hard to identify command on the initiator and command
on the target in the real life output of system log.  For that purpose SCSI
provides a command identifier or task tag (term used in previous
standards). This patch adds tag ID in the system log's output:

TP_printk("%s -> LUN %03u tag %#llx %s data_length %6u  CDB %s  (TA:%s C:%02x)",

kworker/1:1-35    [001] ....  1392.989452: target_sequencer_start:
naa.5001405ec1ba6364 -> LUN 001 tag 0x1
SERVICE_ACTION_IN_16 data_length     32
CDB 9e 10 00 00 00 00 00 00 00 00 00 00 00 20 00 00  (TA:SIMPLE C:00)

kworker/1:1-35    [001] ....  1392.989456: target_cmd_complete:
naa.5001405ec1ba6364 <- LUN 001 tag 0x1 status GOOD (sense len 0)
SERVICE_ACTION_IN_16 data_length     32
CDB 9e 10 00 00 00 00 00 00 00 00 00 00 00 20 00 00  (TA:SIMPLE C:00)

Link: https://lore.kernel.org/r/226e01deaa9baf46d6ff3b8698bc9fe881f7dfc1.camel@dubeyko.comReviewed-by: NRoman Bolshakov <r.bolshakov@yadro.com>
Reviewed-by: NKonstantin Shelekhin <k.shelekhin@yadro.com>
Reviewed-by: NBart van Assche <bvanassche@acm.org>
Signed-off-by: NViacheslav Dubeyko <v.dubeiko@yadro.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

This commit flips the switch to start tracking/processing pinned extents
on a per-transaction basis. It mostly replaces all references from
btrfs_fs_info::(pinned_extents|freed_extents[]) to
btrfs_transaction::pinned_extents.

Two notable modifications that warrant explicit mention are changing
clean_pinned_extents to get a reference to the previously running
transaction. The other one is removal of call to
btrfs_destroy_pinned_extent since transactions are going to be cleaned
in btrfs_cleanup_one_transaction.
Reviewed-by: NJosef Bacik <josef@toxicpanda.com>
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Now that we have a safe way to update the isize, remove all of this code
as it's no longer needed.
Reviewed-by: NFilipe Manana <fdmanana@suse.com>
Signed-off-by: NJosef Bacik <josef@toxicpanda.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

In order to keep track of where we have file extents on disk, and thus
where it is safe to adjust the i_size to, we need to have a tree in
place to keep track of the contiguous areas we have file extents for.

Add helpers to use this tree, as it's not required for NO_HOLES file
systems.  We will use this by setting DIRTY for areas we know we have
file extent item's set, and clearing it when we remove file extent items
for truncation.
Reviewed-by: NFilipe Manana <fdmanana@suse.com>
Signed-off-by: NJosef Bacik <josef@toxicpanda.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Currently, rcu_barrier() ignores offline CPUs,  However, it is possible
for an offline no-CBs CPU to have callbacks queued, and rcu_barrier()
must wait for those callbacks.  This commit therefore makes rcu_barrier()
directly invoke the rcu_barrier_func() with interrupts disabled for such
CPUs.  This requires passing the CPU number into this function so that
it can entrain the rcu_barrier() callback onto the correct CPU's callback
list, given that the code must instead execute on the current CPU.

While in the area, this commit fixes a bug where the first CPU's callback
might have been invoked before rcu_segcblist_entrain() returned, which
would also result in an early wakeup.

Fixes: 5d6742b3 ("rcu/nocb: Use rcu_segcblist for no-CBs CPUs")
Signed-off-by: NPaul E. McKenney <paulmck@kernel.org>
[ paulmck: Apply optimization feedback from Boqun Feng. ]
Cc: <stable@vger.kernel.org> # 5.5.x

Add basic tracing for debugging the sunrpc cache events.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

On some platforms, DMA mapping part of a page is more costly than
copying bytes. Indeed, not involving the I/O MMU can help the
RPC/RDMA transport scale better for tiny I/Os across more RDMA
devices. This is because interaction with the I/O MMU is eliminated
for each of these small I/Os. Without the explicit unmapping, the
NIC no longer needs to do a costly internal TLB shoot down for
buffers that are just a handful of bytes.

Since pull-up is now a more a frequent operation, I've introduced a
trace point in the pull-up path. It can be used for debugging or
user-space tools that count pull-up frequency.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

These trace points are misnamed:

	trace_svcrdma_encode_wseg
	trace_svcrdma_encode_write
	trace_svcrdma_encode_reply
	trace_svcrdma_encode_rseg
	trace_svcrdma_encode_read
	trace_svcrdma_encode_pzr

Because they actually trace posting on the Send Queue. Let's rename
them so that I can add trace points in the chunk list encoders that
actually do trace chunk list encoding events.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

The logic that checks incoming network headers has to be scrupulous.

De-duplicate: replace open-coded buffer overflow checks with the use
of xdr_stream helpers that are used most everywhere else XDR
decoding is done.

One minor change to the sanity checks: instead of checking the
length of individual segments, cap the length of the whole chunk
to be sure it can fit in the set of pages available in rq_pages.
This should be a better test of whether the server can handle the
chunks in each request.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

Clean up. This trace point is no longer needed because the RDMA/core
CMA code has an equivalent trace point that was added by commit
ed999f82 ("RDMA/cma: Add trace points in RDMA Connection
Manager").
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

This class can be used to create trace points in either the RPC
client or RPC server paths. It simply displays the length of each
part of an xdr_buf, which is useful to determine that the transport
and XDR codecs are operating correctly.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

Signed-off-by: NChuck Lever <chuck.lever@oracle.com>

Fix a couple of tracelines to indicate the usage count after the atomic op,
not the usage count before it to be consistent with other afs and rxrpc
trace lines.

Change the wording of the afs_call_trace_work trace ID label from "WORK" to
"QUEUE" to reflect the fact that it's queueing work, not doing work.

Fixes: 341f741f ("afs: Refcount the afs_call struct")
Signed-off-by: NDavid Howells <dhowells@redhat.com>