To quote Alexey[1]:
I was adding custom tracepoint to the kernel, grabbed full F34 kernel
.config, disabled modules and booted whole shebang as VM kernel.
Then did
perf record -a -e ...
It crashed:
general protection fault, probably for non-canonical address 0x435f5346592e4243: 0000 [#1] SMP PTI
CPU: 1 PID: 842 Comm: cat Not tainted 5.12.6+ #26
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-1.fc33 04/01/2014
RIP: 0010:t_show+0x22/0xd0
Then reproducer was narrowed to
# cat /sys/kernel/tracing/printk_formats
Original F34 kernel with modules didn't crash.
So I started to disable options and after disabling AFS everything
started working again.
The root cause is that AFS was placing char arrays content into a
section full of _pointers_ to strings with predictable consequences.
Non canonical address 435f5346592e4243 is "CB.YFS_" which came from
CM_NAME macro.
Steps to reproduce:
CONFIG_AFS=y
CONFIG_TRACING=y
# cat /sys/kernel/tracing/printk_formats
Fix this by the following means:
(1) Add enum->string translation tables in the event header with the AFS
and YFS cache/callback manager operations listed by RPC operation ID.
(2) Modify the afs_cb_call tracepoint to print the string from the
translation table rather than using the string at the afs_call name
pointer.
(3) Switch translation table depending on the service we're being accessed
as (AFS or YFS) in the tracepoint print clause. Will this cause
problems to userspace utilities?
Note that the symbolic representation of the YFS service ID isn't
available to this header, so I've put it in as a number. I'm not sure
if this is the best way to do this.
(4) Remove the name wrangling (CM_NAME) macro and put the names directly
into the afs_call_type structs in cmservice.c.
Fixes: 8e8d7f13b6 ("afs: Add some tracepoints")
Reported-by: Alexey Dobriyan (SK hynix) <adobriyan@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Marc Dionne <marc.dionne@auristor.com>
cc: Andrew Morton <akpm@linux-foundation.org>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/YLAXfvZ+rObEOdc%2F@localhost.localdomain/ [1]
Link: https://lore.kernel.org/r/643721.1623754699@warthog.procyon.org.uk/
Link: https://lore.kernel.org/r/162430903582.2896199.6098150063997983353.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/162609463957.3133237.15916579353149746363.stgit@warthog.procyon.org.uk/ # v1 (repost)
Link: https://lore.kernel.org/r/162610726860.3408253.445207609466288531.stgit@warthog.procyon.org.uk/ # v2
The AFS filesystem driver is handling the CB.ProbeUuid request incorrectly.
The UUID presented in the request is that of the cache manager, not the
fileserver, so afs_deliver_cb_probe_uuid() shouldn't be using that UUID to
look up the server.
Fix this by looking up the server by address instead.
Signed-off-by: David Howells <dhowells@redhat.com>
Don't get the epoch from a server, particularly one that we're looking up
by UUID, as UUIDs may be ambiguous and may map to more than one server - so
we can't draw any conclusions from it.
Reported-by: Jeffrey Altman <jaltman@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
When an AFS client accesses a file, it receives a limited-duration callback
promise that the server will notify it if another client changes a file.
This callback duration can be a few hours in length.
If a client mounts a volume and then an application prevents it from being
unmounted, say by chdir'ing into it, but then does nothing for some time,
the rxrpc_peer record will expire and rxrpc-level keepalive will cease.
If there is NAT or a firewall between the client and the server, the route
back for the server may close after a comparatively short duration, meaning
that attempts by the server to notify the client may then bounce.
The client, however, may (so far as it knows) still have a valid unexpired
promise and will then rely on its cached data and will not see changes made
on the server by a third party until it incidentally rechecks the status or
the promise needs renewal.
To deal with this, the client needs to regularly probe the server. This
has two effects: firstly, it keeps a route open back for the server, and
secondly, it causes the server to disgorge any notifications that got
queued up because they couldn't be sent.
Fix this by adding a mechanism to emit regular probes.
Two levels of probing are made available: Under normal circumstances the
'slow' queue will be used for a fileserver - this just probes the preferred
address once every 5 mins or so; however, if server fails to respond to any
probes, the server will shift to the 'fast' queue from which all its
interfaces will be probed every 30s. When it finally responds, the record
will switch back to the slow queue.
Further notes:
(1) Probing is now no longer driven from the fileserver rotation
algorithm.
(2) Probes are dispatched to all interfaces on a fileserver when that an
afs_server object is set up to record it.
(3) The afs_server object is removed from the probe queues when we start
to probe it. afs_is_probing_server() returns true if it's not listed
- ie. it's undergoing probing.
(4) The afs_server object is added back on to the probe queue when the
final outstanding probe completes, but the probed_at time is set when
we're about to launch a probe so that it's not dependent on the probe
duration.
(5) The timer and the work item added for this must be handed a count on
net->servers_outstanding, which they hand on or release. This makes
sure that network namespace cleanup waits for them.
Fixes: d2ddc776a4 ("afs: Overhaul volume and server record caching and fileserver rotation")
Reported-by: Dave Botsch <botsch@cnf.cornell.edu>
Signed-off-by: David Howells <dhowells@redhat.com>
Split the usage count on the afs_server struct to have an active count that
registers who's actually using it separately from the reference count on
the object.
This allows a future patch to dispatch polling probes without advancing the
"unuse" time into the future each time we emit a probe, which would
otherwise prevent unused server records from expiring.
Included in this:
(1) The latter part of afs_destroy_server() in which the RCU destruction
of afs_server objects is invoked and the outstanding server count is
decremented is split out into __afs_put_server().
(2) afs_put_server() now calls __afs_put_server() rather then setting the
management timer.
(3) The calls begun by afs_fs_give_up_all_callbacks() and
afs_fs_get_capabilities() can now take a ref on the server record, so
afs_destroy_server() can just drop its ref and needn't wait for the
completion of these calls. They'll put the ref when they're done.
(4) Because of (3), afs_fs_probe_done() no longer needs to wake up
afs_destroy_server() with server->probe_outstanding.
(5) afs_gc_servers can be simplified. It only needs to check if
server->active is 0 rather than playing games with the refcount.
(6) afs_manage_servers() can propose a server for gc if usage == 0 rather
than if ref == 1. The gc is effected by (5).
Signed-off-by: David Howells <dhowells@redhat.com>
AFS keeps track of the epoch value from the rxrpc protocol to note (a) when
a fileserver appears to have restarted and (b) when different endpoints of
a fileserver do not appear to be associated with the same fileserver
(ie. all probes back from a fileserver from all of its interfaces should
carry the same epoch).
However, the AFS_SERVER_FL_HAVE_EPOCH flag that indicates that we've
received the server's epoch is never set, though it is used.
Fix this to set the flag when we first receive an epoch value from a probe
sent to the filesystem client from the fileserver.
Fixes: 3bf0fb6f33 ("afs: Probe multiple fileservers simultaneously")
Signed-off-by: David Howells <dhowells@redhat.com>
When an AFS service handler function aborts a call, AF_RXRPC marks the call
as complete - which means that it's not going to get any more packets from
the receiver. This is a problem because reception of the final ACK is what
triggers afs_deliver_to_call() to drop the final ref on the afs_call
object.
Instead, aborted AFS service calls may then just sit around waiting for
ever or until they're displaced by a new call on the same connection
channel or a connection-level abort.
Fix this by calling afs_set_call_complete() to finalise the afs_call struct
representing the call.
However, we then need to drop the ref that stops the call from being
deallocated. We can do this in afs_set_call_complete(), as the work queue
is holding a separate ref of its own, but then we shouldn't do it in
afs_process_async_call() and afs_delete_async_call().
call->drop_ref is set to indicate that a ref needs dropping for a call and
this is dealt with when we transition a call to AFS_CALL_COMPLETE.
But then we also need to get rid of the ref that pins an asynchronous
client call. We can do this by the same mechanism, setting call->drop_ref
for an async client call too.
We can also get rid of call->incoming since nothing ever sets it and only
one thing ever checks it (futilely).
A trace of the rxrpc_call and afs_call struct ref counting looks like:
<idle>-0 [001] ..s5 164.764892: rxrpc_call: c=00000002 SEE u=3 sp=rxrpc_new_incoming_call+0x473/0xb34 a=00000000442095b5
<idle>-0 [001] .Ns5 164.766001: rxrpc_call: c=00000002 QUE u=4 sp=rxrpc_propose_ACK+0xbe/0x551 a=00000000442095b5
<idle>-0 [001] .Ns4 164.766005: rxrpc_call: c=00000002 PUT u=3 sp=rxrpc_new_incoming_call+0xa3f/0xb34 a=00000000442095b5
<idle>-0 [001] .Ns7 164.766433: afs_call: c=00000002 WAKE u=2 o=11 sp=rxrpc_notify_socket+0x196/0x33c
kworker/1:2-1810 [001] ...1 164.768409: rxrpc_call: c=00000002 SEE u=3 sp=rxrpc_process_call+0x25/0x7ae a=00000000442095b5
kworker/1:2-1810 [001] ...1 164.769439: rxrpc_tx_packet: c=00000002 e9f1a7a8:95786a88:00000008:09c5 00000001 00000000 02 22 ACK CallAck
kworker/1:2-1810 [001] ...1 164.769459: rxrpc_call: c=00000002 PUT u=2 sp=rxrpc_process_call+0x74f/0x7ae a=00000000442095b5
kworker/1:2-1810 [001] ...1 164.770794: afs_call: c=00000002 QUEUE u=3 o=12 sp=afs_deliver_to_call+0x449/0x72c
kworker/1:2-1810 [001] ...1 164.770829: afs_call: c=00000002 PUT u=2 o=12 sp=afs_process_async_call+0xdb/0x11e
kworker/1:2-1810 [001] ...2 164.771084: rxrpc_abort: c=00000002 95786a88:00000008 s=0 a=1 e=1 K-1
kworker/1:2-1810 [001] ...1 164.771461: rxrpc_tx_packet: c=00000002 e9f1a7a8:95786a88:00000008:09c5 00000002 00000000 04 00 ABORT CallAbort
kworker/1:2-1810 [001] ...1 164.771466: afs_call: c=00000002 PUT u=1 o=12 sp=SRXAFSCB_ProbeUuid+0xc1/0x106
The abort generated in SRXAFSCB_ProbeUuid(), labelled "K-1", indicates that
the local filesystem/cache manager didn't recognise the UUID as its own.
Fixes: 2067b2b3f4 ("afs: Fix the CB.ProbeUuid service handler to reply correctly")
Signed-off-by: David Howells <dhowells@redhat.com>
Change the name of call->iter to call->def_iter to represent the default
iterator.
Change the name of call->_iter to call->iter to represent the iterator
actually being used.
Signed-off-by: David Howells <dhowells@redhat.com>
Fix the service handler function for the CB.ProbeUuid RPC call so that it
replies in the correct manner - that is an empty reply for success and an
abort of 1 for failure.
Putting 0 or 1 in an integer in the body of the reply should result in the
fileserver throwing an RX_PROTOCOL_ERROR abort and discarding its record of
the client; older servers, however, don't necessarily check that all the
data got consumed, and so might incorrectly think that they got a positive
response and associate the client with the wrong host record.
If the client is incorrectly associated, this will result in callbacks
intended for a different client being delivered to this one and then, when
the other client connects and responds positively, all of the callback
promises meant for the client that issued the improper response will be
lost and it won't receive any further change notifications.
Fixes: 9396d496d7 ("afs: support the CB.ProbeUuid RPC op")
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeffrey Altman <jaltman@auristor.com>
Pull networking updates from David Miller:
"Some highlights from this development cycle:
1) Big refactoring of ipv6 route and neigh handling to support
nexthop objects configurable as units from userspace. From David
Ahern.
2) Convert explored_states in BPF verifier into a hash table,
significantly decreased state held for programs with bpf2bpf
calls, from Alexei Starovoitov.
3) Implement bpf_send_signal() helper, from Yonghong Song.
4) Various classifier enhancements to mvpp2 driver, from Maxime
Chevallier.
5) Add aRFS support to hns3 driver, from Jian Shen.
6) Fix use after free in inet frags by allocating fqdirs dynamically
and reworking how rhashtable dismantle occurs, from Eric Dumazet.
7) Add act_ctinfo packet classifier action, from Kevin
Darbyshire-Bryant.
8) Add TFO key backup infrastructure, from Jason Baron.
9) Remove several old and unused ISDN drivers, from Arnd Bergmann.
10) Add devlink notifications for flash update status to mlxsw driver,
from Jiri Pirko.
11) Lots of kTLS offload infrastructure fixes, from Jakub Kicinski.
12) Add support for mv88e6250 DSA chips, from Rasmus Villemoes.
13) Various enhancements to ipv6 flow label handling, from Eric
Dumazet and Willem de Bruijn.
14) Support TLS offload in nfp driver, from Jakub Kicinski, Dirk van
der Merwe, and others.
15) Various improvements to axienet driver including converting it to
phylink, from Robert Hancock.
16) Add PTP support to sja1105 DSA driver, from Vladimir Oltean.
17) Add mqprio qdisc offload support to dpaa2-eth, from Ioana
Radulescu.
18) Add devlink health reporting to mlx5, from Moshe Shemesh.
19) Convert stmmac over to phylink, from Jose Abreu.
20) Add PTP PHC (Physical Hardware Clock) support to mlxsw, from
Shalom Toledo.
21) Add nftables SYNPROXY support, from Fernando Fernandez Mancera.
22) Convert tcp_fastopen over to use SipHash, from Ard Biesheuvel.
23) Track spill/fill of constants in BPF verifier, from Alexei
Starovoitov.
24) Support bounded loops in BPF, from Alexei Starovoitov.
25) Various page_pool API fixes and improvements, from Jesper Dangaard
Brouer.
26) Just like ipv4, support ref-countless ipv6 route handling. From
Wei Wang.
27) Support VLAN offloading in aquantia driver, from Igor Russkikh.
28) Add AF_XDP zero-copy support to mlx5, from Maxim Mikityanskiy.
29) Add flower GRE encap/decap support to nfp driver, from Pieter
Jansen van Vuuren.
30) Protect against stack overflow when using act_mirred, from John
Hurley.
31) Allow devmap map lookups from eBPF, from Toke Høiland-Jørgensen.
32) Use page_pool API in netsec driver, Ilias Apalodimas.
33) Add Google gve network driver, from Catherine Sullivan.
34) More indirect call avoidance, from Paolo Abeni.
35) Add kTLS TX HW offload support to mlx5, from Tariq Toukan.
36) Add XDP_REDIRECT support to bnxt_en, from Andy Gospodarek.
37) Add MPLS manipulation actions to TC, from John Hurley.
38) Add sending a packet to connection tracking from TC actions, and
then allow flower classifier matching on conntrack state. From
Paul Blakey.
39) Netfilter hw offload support, from Pablo Neira Ayuso"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (2080 commits)
net/mlx5e: Return in default case statement in tx_post_resync_params
mlx5: Return -EINVAL when WARN_ON_ONCE triggers in mlx5e_tls_resync().
net: dsa: add support for BRIDGE_MROUTER attribute
pkt_sched: Include const.h
net: netsec: remove static declaration for netsec_set_tx_de()
net: netsec: remove superfluous if statement
netfilter: nf_tables: add hardware offload support
net: flow_offload: rename tc_cls_flower_offload to flow_cls_offload
net: flow_offload: add flow_block_cb_is_busy() and use it
net: sched: remove tcf block API
drivers: net: use flow block API
net: sched: use flow block API
net: flow_offload: add flow_block_cb_{priv, incref, decref}()
net: flow_offload: add list handling functions
net: flow_offload: add flow_block_cb_alloc() and flow_block_cb_free()
net: flow_offload: rename TCF_BLOCK_BINDER_TYPE_* to FLOW_BLOCK_BINDER_TYPE_*
net: flow_offload: rename TC_BLOCK_{UN}BIND to FLOW_BLOCK_{UN}BIND
net: flow_offload: add flow_block_cb_setup_simple()
net: hisilicon: Add an tx_desc to adapt HI13X1_GMAC
net: hisilicon: Add an rx_desc to adapt HI13X1_GMAC
...
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Merge tag 'afs-next-20190628' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull afs updates from David Howells:
"A set of minor changes for AFS:
- Remove an unnecessary check in afs_unlink()
- Add a tracepoint for tracking callback management
- Add a tracepoint for afs_server object usage
- Use struct_size()
- Add mappings for AFS UAE abort codes to Linux error codes, using
symbolic names rather than hex numbers in the .c file"
* tag 'afs-next-20190628' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
afs: Add support for the UAE error table
fs/afs: use struct_size() in kzalloc()
afs: Trace afs_server usage
afs: Add some callback management tracepoints
afs: afs_unlink() doesn't need to check dentry->d_inode
Some ISDN files that got removed in net-next had some changes
done in mainline, take the removals.
Signed-off-by: David S. Miller <davem@davemloft.net>
David Howells says:
I'm told that there's not really any point populating the list.
Current OpenAFS ignores it, as does AuriStor - and IBM AFS 3.6 will
do the right thing.
The list is actually useless as it's the client's view of the world,
not the servers, so if there's any NAT in the way its contents are
invalid. Further, it doesn't support IPv6 addresses.
On that basis, feel free to make it an empty list and remove all the
interface enumeration.
V1 of this patch reworked the function to use a new helper for the
ifa_list iteration to avoid sparse warnings once the proper __rcu
annotations get added in struct in_device later.
But, in light of the above, just remove afs_get_ipv4_interfaces.
Compile tested only.
Cc: David Howells <dhowells@redhat.com>
Cc: linux-afs@lists.infradead.org
Signed-off-by: Florian Westphal <fw@strlen.de>
Tested-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 3029 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Replace the afs_call::reply[] array with a bunch of typed members so that
the compiler can use type-checking on them. It's also easier for the eye
to see what's going on.
Signed-off-by: David Howells <dhowells@redhat.com>
Hi Linus,
This is my very first pull-request. I've been working full-time as
a kernel developer for more than two years now. During this time I've
been fixing bugs reported by Coverity all over the tree and, as part
of my work, I'm also contributing to the KSPP. My work in the kernel
community has been supervised by Greg KH and Kees Cook.
OK. So, after the quick introduction above, please, pull the following
patches that mark switch cases where we are expecting to fall through.
These patches are part of the ongoing efforts to enable -Wimplicit-fallthrough.
They have been ignored for a long time (most of them more than 3 months,
even after pinging multiple times), which is the reason why I've created
this tree. Most of them have been baking in linux-next for a whole development
cycle. And with Stephen Rothwell's help, we've had linux-next nag-emails
going out for newly introduced code that triggers -Wimplicit-fallthrough
to avoid gaining more of these cases while we work to remove the ones
that are already present.
I'm happy to let you know that we are getting close to completing this
work. Currently, there are only 32 of 2311 of these cases left to be
addressed in linux-next. I'm auditing every case; I take a look into
the code and analyze it in order to determine if I'm dealing with an
actual bug or a false positive, as explained here:
https://lore.kernel.org/lkml/c2fad584-1705-a5f2-d63c-824e9b96cf50@embeddedor.com/
While working on this, I've found and fixed the following missing
break/return bugs, some of them introduced more than 5 years ago:
84242b82d87850b51b6c5e420fe63509186e5034b5be8531817264235ee7cc5034a5d2479826cc865340f23df8df997abeeb2f10d82373307b00c5e65d25ff7a54a7ed5b3e7dc24bfa8f21ad0eaee6199ba8376ce1dc586a60a1a8e9b186f14e57562b4860747828eac5b974bee9cc44ba91162c930e3d0a
Once this work is finish, we'll be able to universally enable
"-Wimplicit-fallthrough" to avoid any of these kinds of bugs from
entering the kernel again.
Thanks
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
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Merge tag 'Wimplicit-fallthrough-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux
Pull Wimplicit-fallthrough updates from Gustavo A. R. Silva:
"Mark switch cases where we are expecting to fall through.
This is part of the ongoing efforts to enable -Wimplicit-fallthrough.
Most of them have been baking in linux-next for a whole development
cycle. And with Stephen Rothwell's help, we've had linux-next
nag-emails going out for newly introduced code that triggers
-Wimplicit-fallthrough to avoid gaining more of these cases while we
work to remove the ones that are already present.
We are getting close to completing this work. Currently, there are
only 32 of 2311 of these cases left to be addressed in linux-next. I'm
auditing every case; I take a look into the code and analyze it in
order to determine if I'm dealing with an actual bug or a false
positive, as explained here:
https://lore.kernel.org/lkml/c2fad584-1705-a5f2-d63c-824e9b96cf50@embeddedor.com/
While working on this, I've found and fixed the several missing
break/return bugs, some of them introduced more than 5 years ago.
Once this work is finished, we'll be able to universally enable
"-Wimplicit-fallthrough" to avoid any of these kinds of bugs from
entering the kernel again"
* tag 'Wimplicit-fallthrough-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux: (27 commits)
memstick: mark expected switch fall-throughs
drm/nouveau/nvkm: mark expected switch fall-throughs
NFC: st21nfca: Fix fall-through warnings
NFC: pn533: mark expected switch fall-throughs
block: Mark expected switch fall-throughs
ASN.1: mark expected switch fall-through
lib/cmdline.c: mark expected switch fall-throughs
lib: zstd: Mark expected switch fall-throughs
scsi: sym53c8xx_2: sym_nvram: Mark expected switch fall-through
scsi: sym53c8xx_2: sym_hipd: mark expected switch fall-throughs
scsi: ppa: mark expected switch fall-through
scsi: osst: mark expected switch fall-throughs
scsi: lpfc: lpfc_scsi: Mark expected switch fall-throughs
scsi: lpfc: lpfc_nvme: Mark expected switch fall-through
scsi: lpfc: lpfc_nportdisc: Mark expected switch fall-through
scsi: lpfc: lpfc_hbadisc: Mark expected switch fall-throughs
scsi: lpfc: lpfc_els: Mark expected switch fall-throughs
scsi: lpfc: lpfc_ct: Mark expected switch fall-throughs
scsi: imm: mark expected switch fall-throughs
scsi: csiostor: csio_wr: mark expected switch fall-through
...
__tracepoint_str cannot be const because the tracepoint_str
section is not read-only. Remove the stray const.
Cc: dhowells@redhat.com
Cc: viro@zeniv.linux.org.uk
Signed-off-by: Andi Kleen <ak@linux.intel.com>
In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.
Notice that in many cases I placed a /* Fall through */ comment
at the bottom of the case, which what GCC is expecting to find.
In other cases I had to tweak a bit the format of the comments.
This patch suppresses ALL missing-break-in-switch false positives
in fs/afs
Addresses-Coverity-ID: 115042 ("Missing break in switch")
Addresses-Coverity-ID: 115043 ("Missing break in switch")
Addresses-Coverity-ID: 115045 ("Missing break in switch")
Addresses-Coverity-ID: 1357430 ("Missing break in switch")
Addresses-Coverity-ID: 115047 ("Missing break in switch")
Addresses-Coverity-ID: 115050 ("Missing break in switch")
Addresses-Coverity-ID: 115051 ("Missing break in switch")
Addresses-Coverity-ID: 1467806 ("Missing break in switch")
Addresses-Coverity-ID: 1467807 ("Missing break in switch")
Addresses-Coverity-ID: 1467811 ("Missing break in switch")
Addresses-Coverity-ID: 115041 ("Missing break in switch")
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Send probes to all the unprobed fileservers in a fileserver list on all
addresses simultaneously in an attempt to find out the fastest route whilst
not getting stuck for 20s on any server or address that we don't get a
reply from.
This alleviates the problem whereby attempting to access a new server can
take a long time because the rotation algorithm ends up rotating through
all servers and addresses until it finds one that responds.
Signed-off-by: David Howells <dhowells@redhat.com>
Implement the YFS cache manager service which gives extra capabilities on
top of AFS. This is done by listening for an additional service on the
same port and indicating that anyone requesting an upgrade should be
upgraded to the YFS port.
Signed-off-by: David Howells <dhowells@redhat.com>
Remove unnecessary details of a broken callback, such as version, expiry
and type, from the afs_callback_break struct as they're not actually used
and make the list take more memory.
Signed-off-by: David Howells <dhowells@redhat.com>
afs_extract_data sets up a temporary iov_iter and passes it to AF_RXRPC
each time it is called to describe the remaining buffer to be filled.
Instead:
(1) Put an iterator in the afs_call struct.
(2) Set the iterator for each marshalling stage to load data into the
appropriate places. A number of convenience functions are provided to
this end (eg. afs_extract_to_buf()).
This iterator is then passed to afs_extract_data().
(3) Use the new ITER_DISCARD iterator to discard any excess data provided
by FetchData.
Signed-off-by: David Howells <dhowells@redhat.com>
Include the site of detection of AFS protocol errors in trace lines to
better be able to determine what went wrong.
Signed-off-by: David Howells <dhowells@redhat.com>
Pull AFS updates from Al Viro:
"Assorted AFS stuff - ended up in vfs.git since most of that consists
of David's AFS-related followups to Christoph's procfs series"
* 'afs-proc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
afs: Optimise callback breaking by not repeating volume lookup
afs: Display manually added cells in dynamic root mount
afs: Enable IPv6 DNS lookups
afs: Show all of a server's addresses in /proc/fs/afs/servers
afs: Handle CONFIG_PROC_FS=n
proc: Make inline name size calculation automatic
afs: Implement network namespacing
afs: Mark afs_net::ws_cell as __rcu and set using rcu functions
afs: Fix a Sparse warning in xdr_decode_AFSFetchStatus()
proc: Add a way to make network proc files writable
afs: Rearrange fs/afs/proc.c to remove remaining predeclarations.
afs: Rearrange fs/afs/proc.c to move the show routines up
afs: Rearrange fs/afs/proc.c by moving fops and open functions down
afs: Move /proc management functions to the end of the file
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Merge tag 'afs-fixes-20180514' into afs-proc
backmerge AFS fixes that went into mainline and deal with
the conflict in fs/afs/fsclient.c
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Implement network namespacing within AFS, but don't yet let mounts occur
outside the init namespace. An additional patch will be required propagate
the network namespace across automounts.
Signed-off-by: David Howells <dhowells@redhat.com>
The handling of CB.CallBack messages sent by the fileserver to the client
is broken in that they are currently being processed after the reply has
been transmitted.
This is not what the fileserver expects, however. It holds up change
visibility until the reply comes so as to maintain cache coherency, and so
expects the client to have to refetch the state on the affected files.
Fix CB.CallBack handling to perform the callback break before sending the
reply.
The fileserver is free to hold up status fetches issued by other threads on
the same client that occur in reponse to the callback until any pending
changes have been committed.
Fixes: d001648ec7 ("rxrpc: Don't expose skbs to in-kernel users [ver #2]")
Signed-off-by: David Howells <dhowells@redhat.com>
If the client cache manager operations that need the server record
(CB.Callback, CB.InitCallBackState, and CB.InitCallBackState3) can't find
the server record, they abort the call from the file server with
RX_CALL_DEAD when they should return okay.
Fixes: c35eccb1f6 ("[AFS]: Implement the CB.InitCallBackState3 operation.")
Signed-off-by: David Howells <dhowells@redhat.com>
Fix the handling of the CB.InitCallBackState3 service call to find the
record of a server that we're using by looking it up by the UUID passed as
the parameter rather than by its address (of which it might have many, and
which may change).
Fixes: c35eccb1f6 ("[AFS]: Implement the CB.InitCallBackState3 operation.")
Signed-off-by: David Howells <dhowells@redhat.com>
When afs_lookup() is called, prospectively look up the next 50 uncached
fids also from that same directory and cache the results, rather than just
looking up the one file requested.
This allows us to use the FS.InlineBulkStatus RPC op to increase efficiency
by fetching up to 50 file statuses at a time.
Signed-off-by: David Howells <dhowells@redhat.com>
Fix warnings raised by checker, including:
(*) Warnings raised by unequal comparison for the purposes of sorting,
where the endianness doesn't matter:
fs/afs/addr_list.c:246:21: warning: restricted __be16 degrades to integer
fs/afs/addr_list.c:246:30: warning: restricted __be16 degrades to integer
fs/afs/addr_list.c:248:21: warning: restricted __be32 degrades to integer
fs/afs/addr_list.c:248:49: warning: restricted __be32 degrades to integer
fs/afs/addr_list.c:283:21: warning: restricted __be16 degrades to integer
fs/afs/addr_list.c:283:30: warning: restricted __be16 degrades to integer
(*) afs_set_cb_interest() is not actually used and can be removed.
(*) afs_cell_gc_delay() should be provided with a sysctl.
(*) afs_cell_destroy() needs to use rcu_access_pointer() to read
cell->vl_addrs.
(*) afs_init_fs_cursor() should be static.
(*) struct afs_vnode::permit_cache needs to be marked __rcu.
(*) afs_server_rcu() needs to use rcu_access_pointer().
(*) afs_destroy_server() should use rcu_access_pointer() on
server->addresses as the server object is no longer accessible.
(*) afs_find_server() casts __be16/__be32 values to int in order to
directly compare them for the purpose of finding a match in a list,
but is should also annotate the cast with __force to avoid checker
warnings.
(*) afs_check_permit() accesses vnode->permit_cache outside of the RCU
readlock, though it doesn't then access the value; the extraneous
access is deleted.
False positives:
(*) Conditional locking around the code in xdr_decode_AFSFetchStatus. This
can be dealt with in a separate patch.
fs/afs/fsclient.c:148:9: warning: context imbalance in 'xdr_decode_AFSFetchStatus' - different lock contexts for basic block
(*) Incorrect handling of seq-retry lock context balance:
fs/afs/inode.c:455:38: warning: context imbalance in 'afs_getattr' - different
lock contexts for basic block
fs/afs/server.c:52:17: warning: context imbalance in 'afs_find_server' - different lock contexts for basic block
fs/afs/server.c:128:17: warning: context imbalance in 'afs_find_server_by_uuid' - different lock contexts for basic block
Errors:
(*) afs_lookup_cell_rcu() needs to break out of the seq-retry loop, not go
round again if it successfully found the workstation cell.
(*) Fix UUID decode in afs_deliver_cb_probe_uuid().
(*) afs_cache_permit() has a missing rcu_read_unlock() before one of the
jumps to the someone_else_changed_it label. Move the unlock to after
the label.
(*) afs_vl_get_addrs_u() is using ntohl() rather than htonl() when
encoding to XDR.
(*) afs_deliver_yfsvl_get_endpoints() is using htonl() rather than ntohl()
when decoding from XDR.
Signed-off-by: David Howells <dhowells@redhat.com>
Protect call->state changes against the call being prematurely terminated
due to a signal.
What can happen is that a signal causes afs_wait_for_call_to_complete() to
abort an afs_call because it's not yet complete whilst afs_deliver_to_call()
is delivering data to that call.
If the data delivery causes the state to change, this may overwrite the state
of the afs_call, making it not-yet-complete again - but no further
notifications will be forthcoming from AF_RXRPC as the rxrpc call has been
aborted and completed, so kAFS will just hang in various places waiting for
that call or on page bits that need clearing by that call.
A tracepoint to monitor call state changes is also provided.
Signed-off-by: David Howells <dhowells@redhat.com>
Overhaul the AFS callback handling by the following means:
(1) Don't give up callback promises on vnodes that we are no longer using,
rather let them just expire on the server or let the server break
them. This is actually more efficient for the server as the callback
lookup is expensive if there are lots of extant callbacks.
(2) Only give up the callback promises we have from a server when the
server record is destroyed. Then we can just give up *all* the
callback promises on it in one go.
(3) Servers can end up being shared between cells if cells are aliased, so
don't add all the vnodes being backed by a particular server into a
big FID-indexed tree on that server as there may be duplicates.
Instead have each volume instance (~= superblock) register an interest
in a server as it starts to make use of it and use this to allow the
processor for callbacks from the server to find the superblock and
thence the inode corresponding to the FID being broken by means of
ilookup_nowait().
(4) Rather than iterating over the entire callback list when a mass-break
comes in from the server, maintain a counter of mass-breaks in
afs_server (cb_seq) and make afs_validate() check it against the copy
in afs_vnode.
It would be nice not to have to take a read_lock whilst doing this,
but that's tricky without using RCU.
(5) Save a ref on the fileserver we're using for a call in the afs_call
struct so that we can access its cb_s_break during call decoding.
(6) Write-lock around callback and status storage in a vnode and read-lock
around getattr so that we don't see the status mid-update.
This has the following consequences:
(1) Data invalidation isn't seen until someone calls afs_validate() on a
vnode. Unfortunately, we need to use a key to query the server, but
getting one from a background thread is tricky without caching loads
of keys all over the place.
(2) Mass invalidation isn't seen until someone calls afs_validate().
(3) Callback breaking is going to hit the inode_hash_lock quite a bit.
Could this be replaced with rcu_read_lock() since inodes are destroyed
under RCU conditions.
Signed-off-by: David Howells <dhowells@redhat.com>
Rename the server member of struct afs_call to cm_server as we're only
going to be using it for incoming calls for the Cache Manager service.
This makes it easier to differentiate from the pointer to the target server
for the client, which will point to a different structure to allow for
callback handling.
Signed-off-by: David Howells <dhowells@redhat.com>
The handler for the CB.ProbeUuid operation in the cache manager is
implemented, but isn't listed in the switch-statement of operation
selection, so won't be used. Fix this by adding it.
Signed-off-by: David Howells <dhowells@redhat.com>
The AFS abort code space is shared across all services, so there's no need
for separate abort_to_error translators for each service.
Consolidate them into a single function and remove the function pointers
for them.
Signed-off-by: David Howells <dhowells@redhat.com>
Push the network namespace pointer to more places in AFS, including the
afs_server structure (which doesn't hold a ref on the netns).
In particular, afs_put_cell() now takes requires a net ns parameter so that
it can safely alter the netns after decrementing the cell usage count - the
cell will be deallocated by a background thread after being cached for a
period, which means that it's not safe to access it after reducing its
usage count.
Signed-off-by: David Howells <dhowells@redhat.com>
Lay the groundwork for supporting network namespaces (netns) to the AFS
filesystem by moving various global features to a network-namespace struct
(afs_net) and providing an instance of this as a temporary global variable
that everything uses via accessor functions for the moment.
The following changes have been made:
(1) Store the netns in the superblock info. This will be obtained from
the mounter's nsproxy on a manual mount and inherited from the parent
superblock on an automount.
(2) The cell list is made per-netns. It can be viewed through
/proc/net/afs/cells and also be modified by writing commands to that
file.
(3) The local workstation cell is set per-ns in /proc/net/afs/rootcell.
This is unset by default.
(4) The 'rootcell' module parameter, which sets a cell and VL server list
modifies the init net namespace, thereby allowing an AFS root fs to be
theoretically used.
(5) The volume location lists and the file lock manager are made
per-netns.
(6) The AF_RXRPC socket and associated I/O bits are made per-ns.
The various workqueues remain global for the moment.
Changes still to be made:
(1) /proc/fs/afs/ should be moved to /proc/net/afs/ and a symlink emplaced
from the old name.
(2) A per-netns subsys needs to be registered for AFS into which it can
store its per-netns data.
(3) Rather than the AF_RXRPC socket being opened on module init, it needs
to be opened on the creation of a superblock in that netns.
(4) The socket needs to be closed when the last superblock using it is
destroyed and all outstanding client calls on it have been completed.
This prevents a reference loop on the namespace.
(5) It is possible that several namespaces will want to use AFS, in which
case each one will need its own UDP port. These can either be set
through /proc/net/afs/cm_port or the kernel can pick one at random.
The init_ns gets 7001 by default.
Other issues that need resolving:
(1) The DNS keyring needs net-namespacing.
(2) Where do upcalls go (eg. DNS request-key upcall)?
(3) Need something like open_socket_in_file_ns() syscall so that AFS
command line tools attempting to operate on an AFS file/volume have
their RPC calls go to the right place.
Signed-off-by: David Howells <dhowells@redhat.com>
This essentially is a partial revert of commit ff548773
("afs: Move UUID struct to linux/uuid.h") and moves struct uuid_v1 back into
fs/afs as struct afs_uuid. It however keeps it as big endian structure
so that we can use the normal uuid generation helpers when casting to/from
struct afs_uuid.
The V1 uuid intrepretation in struct form isn't really useful to the
rest of the kernel, and not really compatible to it either, so move it
back to AFS instead of polluting the global uuid.h.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: David Howells <dhowells@redhat.com>
Servers may send a callback array that is the same size as
the FID array, or an empty array. If the callback count is
0, the code would attempt to read (fid_count * 12) bytes of
data, which would fail and result in an unmarshalling error.
This would lead to stale data for remotely modified files
or directories.
Store the callback array size in the internal afs_call
structure and use that to determine the amount of data to
read.
Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
Move the afs_uuid struct to linux/uuid.h, rename it to uuid_v1 and change
the u16/u32 fields to __be16/__be32 instead so that the structure can be
cast to a 16-octet network-order buffer.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de
A static checker warning occurs in the AFS filesystem:
fs/afs/cmservice.c:155 SRXAFSCB_CallBack()
error: dereferencing freed memory 'call'
due to the reply being sent before we access the server it points to. The
act of sending the reply causes the call to be freed if an error occurs
(but not if it doesn't).
On top of this, the lifetime handling of afs_call structs is fragile
because they get passed around through workqueues without any sort of
refcounting.
Deal with the issues by:
(1) Fix the maybe/maybe not nature of the reply sending functions with
regards to whether they release the call struct.
(2) Refcount the afs_call struct and sort out places that need to get/put
references.
(3) Pass a ref through the work queue and release (or pass on) that ref in
the work function. Care has to be taken because a work queue may
already own a ref to the call.
(4) Do the cleaning up in the put function only.
(5) Simplify module cleanup by always incrementing afs_outstanding_calls
whenever a call is allocated.
(6) Set the backlog to 0 with kernel_listen() at the beginning of the
process of closing the socket to prevent new incoming calls from
occurring and to remove the contribution of preallocated calls from
afs_outstanding_calls before we wait on it.
A tracepoint is also added to monitor the afs_call refcount and lifetime.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Fixes: 08e0e7c82eea: "[AF_RXRPC]: Make the in-kernel AFS filesystem use AF_RXRPC."
David Howells