MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/5525
JIRA: https://issues.redhat.com/browse/RHEL-63701
CVE: CVE-2022-48989
```
fscache: Fix oops due to race with cookie_lru and use_cookie
If a cookie expires from the LRU and the LRU_DISCARD flag is set, but
the state machine has not run yet, it's possible another thread can call
fscache_use_cookie and begin to use it.
When the cookie_worker finally runs, it will see the LRU_DISCARD flag
set, transition the cookie->state to LRU_DISCARDING, which will then
withdraw the cookie. Once the cookie is withdrawn the object is removed
the below oops will occur because the object associated with the cookie
is now NULL.
Fix the oops by clearing the LRU_DISCARD bit if another thread uses the
cookie before the cookie_worker runs.
BUG: kernel NULL pointer dereference, address: 0000000000000008
...
CPU: 31 PID: 44773 Comm: kworker/u130:1 Tainted: G E 6.0.0-5.dneg.x86_64 #1
Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022
Workqueue: events_unbound netfs_rreq_write_to_cache_work [netfs]
RIP: 0010:cachefiles_prepare_write+0x28/0x90 [cachefiles]
...
Call Trace:
netfs_rreq_write_to_cache_work+0x11c/0x320 [netfs]
process_one_work+0x217/0x3e0
worker_thread+0x4a/0x3b0
kthread+0xd6/0x100
Fixes: 12bb21a29c19 ("fscache: Implement cookie user counting and resource pinning")
Reported-by: Daire Byrne <daire.byrne@gmail.com>
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Daire Byrne <daire@dneg.com>
Link: https://lore.kernel.org/r/20221117115023.1350181-1-dwysocha@redhat.com/ # v1
Link: https://lore.kernel.org/r/20221117142915.1366990-1-dwysocha@redhat.com/ # v2
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit b5b52de3214a29911f949459a79f6640969b5487)
```
Signed-off-by: CKI Backport Bot <cki-ci-bot+cki-gitlab-backport-bot@redhat.com>
---
<small>Created 2024-10-22 12:03 UTC by backporter - [KWF FAQ](https://red.ht/kernel_workflow_doc) - [Slack #team-kernel-workflow](https://redhat-internal.slack.com/archives/C04LRUPMJQ5) - [Source](https://gitlab.com/cki-project/kernel-workflow/-/blob/main/webhook/utils/backporter.py) - [Documentation](https://gitlab.com/cki-project/kernel-workflow/-/blob/main/docs/README.backporter.md) - [Report an issue](https://gitlab.com/cki-project/kernel-workflow/-/issues/new?issue%5Btitle%5D=backporter%20webhook%20issue)</small>
Approved-by: David Howells <dhowells@redhat.com>
Approved-by: Brian Foster <bfoster@redhat.com>
Approved-by: CKI KWF Bot <cki-ci-bot+kwf-gitlab-com@redhat.com>
Merged-by: Rado Vrbovsky <rvrbovsk@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-57214
CVE: CVE-2024-45000
commit f71aa06398aabc2e3eaac25acdf3d62e0094ba70
Author: Max Kellermann <max.kellermann@ionos.com>
Date: Mon Jul 29 17:19:30 2024 +0100
fs/netfs/fscache_cookie: add missing "n_accesses" check
This fixes a NULL pointer dereference bug due to a data race which
looks like this:
BUG: kernel NULL pointer dereference, address: 0000000000000008
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] SMP PTI
CPU: 33 PID: 16573 Comm: kworker/u97:799 Not tainted 6.8.7-cm4all1-hp+ #43
Hardware name: HP ProLiant DL380 Gen9/ProLiant DL380 Gen9, BIOS P89 10/17/2018
Workqueue: events_unbound netfs_rreq_write_to_cache_work
RIP: 0010:cachefiles_prepare_write+0x30/0xa0
Code: 57 41 56 45 89 ce 41 55 49 89 cd 41 54 49 89 d4 55 53 48 89 fb 48 83 ec 08 48 8b 47 08 48 83 7f 10 00 48 89 34 24 48 8b 68 20 <48> 8b 45 08 4c 8b 38 74 45 49 8b 7f 50 e8 4e a9 b0 ff 48 8b 73 10
RSP: 0018:ffffb4e78113bde0 EFLAGS: 00010286
RAX: ffff976126be6d10 RBX: ffff97615cdb8438 RCX: 0000000000020000
RDX: ffff97605e6c4c68 RSI: ffff97605e6c4c60 RDI: ffff97615cdb8438
RBP: 0000000000000000 R08: 0000000000278333 R09: 0000000000000001
R10: ffff97605e6c4600 R11: 0000000000000001 R12: ffff97605e6c4c68
R13: 0000000000020000 R14: 0000000000000001 R15: ffff976064fe2c00
FS: 0000000000000000(0000) GS:ffff9776dfd40000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000008 CR3: 000000005942c002 CR4: 00000000001706f0
Call Trace:
<TASK>
? __die+0x1f/0x70
? page_fault_oops+0x15d/0x440
? search_module_extables+0xe/0x40
? fixup_exception+0x22/0x2f0
? exc_page_fault+0x5f/0x100
? asm_exc_page_fault+0x22/0x30
? cachefiles_prepare_write+0x30/0xa0
netfs_rreq_write_to_cache_work+0x135/0x2e0
process_one_work+0x137/0x2c0
worker_thread+0x2e9/0x400
? __pfx_worker_thread+0x10/0x10
kthread+0xcc/0x100
? __pfx_kthread+0x10/0x10
ret_from_fork+0x30/0x50
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1b/0x30
</TASK>
Modules linked in:
CR2: 0000000000000008
---[ end trace 0000000000000000 ]---
This happened because fscache_cookie_state_machine() was slow and was
still running while another process invoked fscache_unuse_cookie();
this led to a fscache_cookie_lru_do_one() call, setting the
FSCACHE_COOKIE_DO_LRU_DISCARD flag, which was picked up by
fscache_cookie_state_machine(), withdrawing the cookie via
cachefiles_withdraw_cookie(), clearing cookie->cache_priv.
At the same time, yet another process invoked
cachefiles_prepare_write(), which found a NULL pointer in this code
line:
struct cachefiles_object *object = cachefiles_cres_object(cres);
The next line crashes, obviously:
struct cachefiles_cache *cache = object->volume->cache;
During cachefiles_prepare_write(), the "n_accesses" counter is
non-zero (via fscache_begin_operation()). The cookie must not be
withdrawn until it drops to zero.
The counter is checked by fscache_cookie_state_machine() before
switching to FSCACHE_COOKIE_STATE_RELINQUISHING and
FSCACHE_COOKIE_STATE_WITHDRAWING (in "case
FSCACHE_COOKIE_STATE_FAILED"), but not for
FSCACHE_COOKIE_STATE_LRU_DISCARDING ("case
FSCACHE_COOKIE_STATE_ACTIVE").
This patch adds the missing check. With a non-zero access counter,
the function returns and the next fscache_end_cookie_access() call
will queue another fscache_cookie_state_machine() call to handle the
still-pending FSCACHE_COOKIE_DO_LRU_DISCARD.
Fixes: 12bb21a29c19 ("fscache: Implement cookie user counting and resource pinning")
Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20240729162002.3436763-2-dhowells@redhat.com
cc: Jeff Layton <jlayton@kernel.org>
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
cc: stable@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: CKI Backport Bot <cki-ci-bot+cki-gitlab-backport-bot@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-63701
CVE: CVE-2022-48989
commit b5b52de3214a29911f949459a79f6640969b5487
Author: Dave Wysochanski <dwysocha@redhat.com>
Date: Wed Dec 7 13:49:15 2022 +0000
fscache: Fix oops due to race with cookie_lru and use_cookie
If a cookie expires from the LRU and the LRU_DISCARD flag is set, but
the state machine has not run yet, it's possible another thread can call
fscache_use_cookie and begin to use it.
When the cookie_worker finally runs, it will see the LRU_DISCARD flag
set, transition the cookie->state to LRU_DISCARDING, which will then
withdraw the cookie. Once the cookie is withdrawn the object is removed
the below oops will occur because the object associated with the cookie
is now NULL.
Fix the oops by clearing the LRU_DISCARD bit if another thread uses the
cookie before the cookie_worker runs.
BUG: kernel NULL pointer dereference, address: 0000000000000008
...
CPU: 31 PID: 44773 Comm: kworker/u130:1 Tainted: G E 6.0.0-5.dneg.x86_64 #1
Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022
Workqueue: events_unbound netfs_rreq_write_to_cache_work [netfs]
RIP: 0010:cachefiles_prepare_write+0x28/0x90 [cachefiles]
...
Call Trace:
netfs_rreq_write_to_cache_work+0x11c/0x320 [netfs]
process_one_work+0x217/0x3e0
worker_thread+0x4a/0x3b0
kthread+0xd6/0x100
Fixes: 12bb21a29c19 ("fscache: Implement cookie user counting and resource pinning")
Reported-by: Daire Byrne <daire.byrne@gmail.com>
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Daire Byrne <daire@dneg.com>
Link: https://lore.kernel.org/r/20221117115023.1350181-1-dwysocha@redhat.com/ # v1
Link: https://lore.kernel.org/r/20221117142915.1366990-1-dwysocha@redhat.com/ # v2
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: CKI Backport Bot <cki-ci-bot+cki-gitlab-backport-bot@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-59451
CVE: CVE-2024-46786
commit 72a6e22c604c95ddb3b10b5d3bb85b6ff4dbc34f
Author: Baokun Li <libaokun1@huawei.com>
Date: Mon Aug 26 19:20:56 2024 +0800
fscache: delete fscache_cookie_lru_timer when fscache exits to avoid UAF
The fscache_cookie_lru_timer is initialized when the fscache module
is inserted, but is not deleted when the fscache module is removed.
If timer_reduce() is called before removing the fscache module,
the fscache_cookie_lru_timer will be added to the timer list of
the current cpu. Afterwards, a use-after-free will be triggered
in the softIRQ after removing the fscache module, as follows:
==================================================================
BUG: unable to handle page fault for address: fffffbfff803c9e9
PF: supervisor read access in kernel mode
PF: error_code(0x0000) - not-present page
PGD 21ffea067 P4D 21ffea067 PUD 21ffe6067 PMD 110a7c067 PTE 0
Oops: Oops: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G W 6.11.0-rc3 #855
Tainted: [W]=WARN
RIP: 0010:__run_timer_base.part.0+0x254/0x8a0
Call Trace:
<IRQ>
tmigr_handle_remote_up+0x627/0x810
__walk_groups.isra.0+0x47/0x140
tmigr_handle_remote+0x1fa/0x2f0
handle_softirqs+0x180/0x590
irq_exit_rcu+0x84/0xb0
sysvec_apic_timer_interrupt+0x6e/0x90
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:default_idle+0xf/0x20
default_idle_call+0x38/0x60
do_idle+0x2b5/0x300
cpu_startup_entry+0x54/0x60
start_secondary+0x20d/0x280
common_startup_64+0x13e/0x148
</TASK>
Modules linked in: [last unloaded: netfs]
==================================================================
Therefore delete fscache_cookie_lru_timer when removing the fscahe module.
Fixes: 12bb21a29c19 ("fscache: Implement cookie user counting and resource pinning")
Cc: stable@kernel.org
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Link: https://lore.kernel.org/r/20240826112056.2458299-1-libaokun@huaweicloud.com
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: CKI Backport Bot <cki-ci-bot+cki-gitlab-backport-bot@redhat.com>
Conflicts: Mismatch of file names from fs/fscache/{internal.h, volume.c}
to fs/netfs/{internal.h, fscache_volume.c} caused by the absence of
upstream commit 47757ea83a54 ("netfs, fscache: Move fs/fscache/* into
fs/netfs/").
JIRA: https://issues.redhat.com/browse/RHEL-51157
JIRA: https://issues.redhat.com/browse/RHEL-51163
Export fscache_put_volume() and add fscache_try_get_volume()
helper function to allow cachefiles to get/put fscache_volume
via linux/fscache-cache.h.
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Link: https://lore.kernel.org/r/20240628062930.2467993-2-libaokun@huaweicloud.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
(cherry picked from commit 85b08b31a22b481ec6528130daf94eee4452e23f)
Signed-off-by: Pavel Reichl <preichl@redhat.com>
JIRA: https://issues.redhat.com/browse/RHEL-32199
Upstream Status: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Note: The core of this patch was already backported in commit 0d33f8e1f3.
And later commit a9e6d7970e back ported cifs part. This patch tries
to back port the remaining parts which doesn't have conficts. This
change is easing code reading and understanding, not related to
functionality or features, hence leave those parts to module developer
to back port when dependency is met.
commit de4eda9de2d957ef2d6a8365a01e26a435e958cb
Author: Al Viro <viro@zeniv.linux.org.uk>
Date: Thu Sep 15 20:25:47 2022 -0400
use less confusing names for iov_iter direction initializers
READ/WRITE proved to be actively confusing - the meanings are
"data destination, as used with read(2)" and "data source, as
used with write(2)", but people keep interpreting those as
"we read data from it" and "we write data to it", i.e. exactly
the wrong way.
Call them ITER_DEST and ITER_SOURCE - at least that is harder
to misinterpret...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Baoquan He <bhe@redhat.com>
This function dereferences "cache" and then checks if it's
IS_ERR_OR_NULL(). Check first, then dereference.
Fixes: 9549332df4ed ("fscache: Implement cache registration")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/e84bc740-3502-4f16-982a-a40d5676615c@moroto.mountain/ # v2
(cherry picked from commit 3be0b3ed1d76c6703b9ee482b55f7e01c369cc68)
JIRA: https://issues.redhat.com/browse/RHEL-28890
CVE: CVE-2024-26612
Signed-off-by: Pavel Reichl <preichl@redhat.com>
Conflicts:
drop changes to fs/9p/vfs_addr.c - unsupported fs
fs/afs/file.c - We already have
bc899ee1c898 ("netfs: Add a netfs inode context")
so just remove the .set_page_dirty entry and replace it with
the .dirty_folio entry
Bugzilla: https://bugzilla.redhat.com/2120352
commit 8fb72b4a76933ae6f86725cc8e4a8190ba84d755
Author: Matthew Wilcox (Oracle) <willy@infradead.org>
Date: Wed Feb 9 20:22:01 2022 +0000
fscache: Convert fscache_set_page_dirty() to fscache_dirty_folio()
Convert all users of fscache_set_page_dirty to use fscache_dirty_folio.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Tested-by: Mike Marshall <hubcap@omnibond.com> # orangefs
Tested-by: David Howells <dhowells@redhat.com> # afs
Signed-off-by: Chris von Recklinghausen <crecklin@redhat.com>
Bugzilla: http://bugzilla.redhat.com/1229736
commit fb24771faf72a2fd62b3b6287af3c610c3ec9cf1
Author: Jeff Layton <jlayton@kernel.org>
Date: Fri Aug 5 06:42:45 2022 -0400
fscache: don't leak cookie access refs if invalidation is in progress or failed
It's possible for a request to invalidate a fscache_cookie will come in
while we're already processing an invalidation. If that happens we
currently take an extra access reference that will leak. Only call
__fscache_begin_cookie_access if the FSCACHE_COOKIE_DO_INVALIDATE bit
was previously clear.
Also, ensure that we attempt to clear the bit when the cookie is
"FAILED" and put the reference to avoid an access leak.
Fixes: 85e4ea1049c7 ("fscache: Fix invalidation/lookup race")
Suggested-by: David Howells <dhowells@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Jeffrey Layton <jlayton@redhat.com>
Bugzilla: http://bugzilla.redhat.com/1229736
commit 85e4ea1049c70fb99de5c6057e835d151fb647da
Author: David Howells <dhowells@redhat.com>
Date: Wed Apr 20 14:27:17 2022 +0100
fscache: Fix invalidation/lookup race
If an NFS file is opened for writing and closed, fscache_invalidate() will
be asked to invalidate the file - however, if the cookie is in the
LOOKING_UP state (or the CREATING state), then request to invalidate
doesn't get recorded for fscache_cookie_state_machine() to do something
with.
Fix this by making __fscache_invalidate() set a flag if it sees the cookie
is in the LOOKING_UP state to indicate that we need to go to invalidation.
Note that this requires a count on the n_accesses counter for the state
machine, which that will release when it's done.
fscache_cookie_state_machine() then shifts to the INVALIDATING state if it
sees the flag.
Without this, an nfs file can get corrupted if it gets modified locally and
then read locally as the cache contents may not get updated.
Fixes: d24af13e2e23 ("fscache: Implement cookie invalidation")
Reported-by: Max Kellermann <mk@cm4all.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Max Kellermann <mk@cm4all.com>
Link: https://lore.kernel.org/r/YlWWbpW5Foynjllo@rabbit.intern.cm-ag [1]
Signed-off-by: Jeffrey Layton <jlayton@redhat.com>
Bugzilla: http://bugzilla.redhat.com/1229736
commit 5c4588aea6675b69e328d468c5b6be5127e19a79
Author: Yue Hu <zbestahu@gmail.com>
Date: Wed May 25 10:51:50 2022 +0800
fscache: Introduce fscache_cookie_is_dropped()
FSCACHE_COOKIE_STATE_DROPPED will be read more than once, so let's add a
helper to avoid code duplication.
Signed-off-by: Yue Hu <huyue2@coolpad.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://listman.redhat.com/archives/linux-cachefs/2022-May/006919.html
Signed-off-by: Jeffrey Layton <jlayton@redhat.com>
Bugzilla: http://bugzilla.redhat.com/1229736
commit bf17455b9cbd4b10bf30d39c047307e1d774fb1a
Author: Yue Hu <huyue2@coolpad.com>
Date: Wed May 25 10:32:22 2022 +0800
fscache: Fix if condition in fscache_wait_on_volume_collision()
After waiting for the volume to complete the acquisition with timeout,
the if condition under which potential volume collision occurs should be
acquire the volume is still pending rather than not pending so that we
will continue to wait until the pending flag is cleared. Also, use the
existing test pending wrapper directly instead of test_bit().
Fixes: 62ab63352350 ("fscache: Implement volume registration")
Signed-off-by: Yue Hu <huyue2@coolpad.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Jeffle Xu <jefflexu@linux.alibaba.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Link: https://listman.redhat.com/archives/linux-cachefs/2022-May/006918.html
Signed-off-by: Jeffrey Layton <jlayton@redhat.com>
Bugzilla: http://bugzilla.redhat.com/1229736
commit b3c958c20a61fb8514fa16e3edcb421703600ee0
Author: Yue Hu <huyue2@coolpad.com>
Date: Fri Apr 1 14:37:15 2022 +0800
fscache: Use wrapper fscache_set_cache_state() directly when relinquishing
We already have the wrapper function to set cache state.
Signed-off-by: Yue Hu <huyue2@coolpad.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeffle Xu <jefflexu@linux.alibaba.com>
cc: linux-cachefs@redhat.com
Link: https://listman.redhat.com/archives/linux-cachefs/2022-April/006648.html # v1
Signed-off-by: Jeffrey Layton <jlayton@redhat.com>
Bugzilla: http://bugzilla.redhat.com/1229736
commit 19517e53740ec671c335f05089abe1f0720103c7
Author: Yue Hu <huyue2@coolpad.com>
Date: Sat Apr 2 12:47:43 2022 +0800
fscache: Move fscache_cookies_seq_ops specific code under CONFIG_PROC_FS
fscache_cookies_seq_ops is only used in proc.c that is compiled under
enabled CONFIG_PROC_FS, so move related code under this config. The
same case exsits in internal.h.
Also, make fscache_lru_cookie_timeout static due to no user outside
of cookie.c.
Signed-off-by: Yue Hu <huyue2@coolpad.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-cachefs@redhat.com
Link: https://listman.redhat.com/archives/linux-cachefs/2022-April/006649.html # v1
Signed-off-by: Jeffrey Layton <jlayton@redhat.com>
Bugzilla: http://bugzilla.redhat.com/1229736
Conflicts: Documentation conflicts
commit 2c547f299827c12244d613eb2ee3616d88f56088
Author: Yue Hu <huyue2@coolpad.com>
Date: Wed Apr 6 11:50:17 2022 +0800
fscache: Remove the cookie parameter from fscache_clear_page_bits()
The cookie is not used at all, remove it and update the usage in io.c
and afs/write.c (which is the only user outside of fscache currently)
at the same time.
[DH: Amended the documentation also]
Signed-off-by: Yue Hu <huyue2@coolpad.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-cachefs@redhat.com
Link: https://listman.redhat.com/archives/linux-cachefs/2022-April/006659.html
Signed-off-by: Jeffrey Layton <jlayton@redhat.com>
Bugzilla: http://bugzilla.redhat.com/1229736
commit 80a00ab8344f0fe4d555a1f97960215b659436e9
Author: David Howells <dhowells@redhat.com>
Date: Fri Jan 14 13:30:17 2022 +0000
fscache: Fix the volume collision wait condition
The condition that the waits in fscache_wait_on_volume_collision() are
waiting until are inverted. This suddenly started happening on the
upstream kernel with something like the following appearing in dmesg when
running xfstests:
CacheFiles: cachefiles: Inode already in use: Iafs,example.com,100055
Fix them by inverting the conditions.
Fixes: 62ab63352350 ("fscache: Implement volume registration")
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/164251398010.3435901.943876048104930939.stgit@warthog.procyon.org.uk/ # v1
Signed-off-by: Jeffrey Layton <jlayton@redhat.com>
Bugzilla: http://bugzilla.redhat.com/1229736
commit 08276bdae68b022a7726edf7416b6748e3df5395
Author: David Howells <dhowells@redhat.com>
Date: Wed Oct 20 23:50:01 2021 +0100
vfs, fscache: Implement pinning of cache usage for writeback
Cachefiles has a problem in that it needs to keep the backing file for a
cookie open whilst there are local modifications pending that need to be
written to it. However, we don't want to keep the file open indefinitely,
as that causes EMFILE/ENFILE/ENOMEM problems.
Reopening the cache file, however, is a problem if this is being done due
to writeback triggered by exit(). Some filesystems will oops if we try to
open a file in that context because they want to access current->fs or
other resources that have already been dismantled.
To get around this, I added the following:
(1) An inode flag, I_PINNING_FSCACHE_WB, to be set on a network filesystem
inode to indicate that we have a usage count on the cookie caching
that inode.
(2) A flag in struct writeback_control, unpinned_fscache_wb, that is set
when __writeback_single_inode() clears the last dirty page from
i_pages - at which point it clears I_PINNING_FSCACHE_WB and sets this
flag.
This has to be done here so that clearing I_PINNING_FSCACHE_WB can be
done atomically with the check of PAGECACHE_TAG_DIRTY that clears
I_DIRTY_PAGES.
(3) A function, fscache_set_page_dirty(), which if it is not set, sets
I_PINNING_FSCACHE_WB and calls fscache_use_cookie() to pin the cache
resources.
(4) A function, fscache_unpin_writeback(), to be called by ->write_inode()
to unuse the cookie.
(5) A function, fscache_clear_inode_writeback(), to be called when the
inode is evicted, before clear_inode() is called. This cleans up any
lingering I_PINNING_FSCACHE_WB.
The network filesystem can then use these tools to make sure that
fscache_write_to_cache() can write locally modified data to the cache as
well as to the server.
For the future, I'm working on write helpers for netfs lib that should
allow this facility to be removed by keeping track of the dirty regions
separately - but that's incomplete at the moment and is also going to be
affected by folios, one way or another, since it deals with pages
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/163819615157.215744.17623791756928043114.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/163906917856.143852.8224898306177154573.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/163967124567.1823006.14188359004568060298.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/164021524705.640689.17824932021727663017.stgit@warthog.procyon.org.uk/ # v4
Signed-off-by: Jeffrey Layton <jlayton@redhat.com>
Bugzilla: http://bugzilla.redhat.com/1229736
commit b6e16652d6c0e4f9e9b120f66966ec153f0623fc
Author: David Howells <dhowells@redhat.com>
Date: Wed Oct 20 14:06:34 2021 +0100
fscache: Implement higher-level write I/O interface
Provide a higher-level function than fscache_write() to perform a write
from an inode's pagecache to the cache, whilst fending off concurrent
writes by means of the PG_fscache mark on a page:
void fscache_write_to_cache(struct fscache_cookie *cookie,
struct address_space *mapping,
loff_t start,
size_t len,
loff_t i_size,
netfs_io_terminated_t term_func,
void *term_func_priv,
bool caching);
If caching is false, this function does nothing except call (*term_func)()
if given. It assumes that, in such a case, PG_fscache will not have been
set on the pages.
Otherwise, if caching is true, this function requires the source pages to
have had PG_fscache set on them before calling. start and len define the
region of the file to be modified and i_size indicates the new file size.
The source pages are extracted from the mapping.
term_func and term_func_priv work as for fscache_write(). The PG_fscache
marks will be cleared at the end of the operation, before term_func is
called or the function otherwise returns.
There is an additonal helper function to clear the PG_fscache bits from a
range of pages:
void fscache_clear_page_bits(struct fscache_cookie *cookie,
struct address_space *mapping,
loff_t start, size_t len,
bool caching);
If caching is true, the pages to be managed are expected to be located on
mapping in the range defined by start and len. If caching is false, it
does nothing.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/163819614155.215744.5528123235123721230.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/163906916346.143852.15632773570362489926.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/163967123599.1823006.12946816026724657428.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/164021522672.640689.4381958316198807813.stgit@warthog.procyon.org.uk/ # v4
Signed-off-by: Jeffrey Layton <jlayton@redhat.com>
Bugzilla: http://bugzilla.redhat.com/1229736
commit d64f4554dd177c5891c02424a8d9e80590b55b35
Author: David Howells <dhowells@redhat.com>
Date: Wed Oct 20 14:06:34 2021 +0100
fscache: Provide a means to begin an operation
Provide a function to begin a read operation:
int fscache_begin_read_operation(
struct netfs_cache_resources *cres,
struct fscache_cookie *cookie)
This is primarily intended to be called by network filesystems on behalf of
netfslib, but may also be called to use the I/O access functions directly.
It attaches the resources required by the cache to cres struct from the
supplied cookie.
This holds access to the cache behind the cookie for the duration of the
operation and forces cache withdrawal and cookie invalidation to perform
synchronisation on the operation. cres->inval_counter is set from the
cookie at this point so that it can be compared at the end of the
operation.
Note that this does not guarantee that the cache state is fully set up and
able to perform I/O immediately; looking up and creation may be left in
progress in the background. The operations intended to be called by the
network filesystem, such as reading and writing, are expected to wait for
the cookie to move to the correct state.
This will, however, potentially sleep, waiting for a certain minimum state
to be set or for operations such as invalidate to advance far enough that
I/O can resume.
Also provide a function for the cache to call to wait for the cache object
to get to a state where it can be used for certain things:
bool fscache_wait_for_operation(struct netfs_cache_resources *cres,
enum fscache_want_stage stage);
This looks at the cache resources provided by the begin function and waits
for them to get to an appropriate stage. There's a choice of wanting just
some parameters (FSCACHE_WANT_PARAM) or the ability to do I/O
(FSCACHE_WANT_READ or FSCACHE_WANT_WRITE).
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/163819603692.215744.146724961588817028.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/163906910672.143852.13856103384424986357.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/163967110245.1823006.2239170567540431836.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/164021513617.640689.16627329360866150606.stgit@warthog.procyon.org.uk/ # v4
Signed-off-by: Jeffrey Layton <jlayton@redhat.com>
Bugzilla: http://bugzilla.redhat.com/1229736
commit 12bb21a29c19aae50cfad4e2bb5c943108f34a7d
Author: David Howells <dhowells@redhat.com>
Date: Wed Oct 20 15:53:34 2021 +0100
fscache: Implement cookie user counting and resource pinning
Provide a pair of functions to count the number of users of a cookie (open
files, writeback, invalidation, resizing, reads, writes), to obtain and pin
resources for the cookie and to prevent culling for the whilst there are
users.
The first function marks a cookie as being in use:
void fscache_use_cookie(struct fscache_cookie *cookie,
bool will_modify);
The caller should indicate the cookie to use and whether or not the caller
is in a context that may modify the cookie (e.g. a file open O_RDWR).
If the cookie is not already resourced, fscache will ask the cache backend
in the background to do whatever it needs to look up, create or otherwise
obtain the resources necessary to access data. This is pinned to the
cookie and may not be culled, though it may be withdrawn if the cache as a
whole is withdrawn.
The second function removes the in-use mark from a cookie and, optionally,
updates the coherency data:
void fscache_unuse_cookie(struct fscache_cookie *cookie,
const void *aux_data,
const loff_t *object_size);
If non-NULL, the aux_data buffer and/or the object_size will be saved into
the cookie and will be set on the backing store when the object is
committed.
If this removes the last usage on a cookie, the cookie is placed onto an
LRU list from which it will be removed and closed after a couple of seconds
if it doesn't get reused. This prevents resource overload in the cache -
in particular it prevents it from holding too many files open.
Changes
=======
ver #2:
- Fix fscache_unuse_cookie() to use atomic_dec_and_lock() to avoid a
potential race if the cookie gets reused before it completes the
unusement.
- Added missing transition to LRU_DISCARDING state.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/163819600612.215744.13678350304176542741.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/163906907567.143852.16979631199380722019.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/163967106467.1823006.6790864931048582667.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/164021511674.640689.10084988363699111860.stgit@warthog.procyon.org.uk/ # v4
Signed-off-by: Jeffrey Layton <jlayton@redhat.com>
Bugzilla: http://bugzilla.redhat.com/1229736
commit a7733fb632722a2f085f9324f14783effe268ed3
Author: David Howells <dhowells@redhat.com>
Date: Wed Oct 20 15:53:34 2021 +0100
fscache: Implement cookie-level access helpers
Add a number of helper functions to manage access to a cookie, pinning the
cache object in place for the duration to prevent cache withdrawal from
removing it:
(1) void fscache_init_access_gate(struct fscache_cookie *cookie);
This function initialises the access count when a cache binds to a
cookie. An extra ref is taken on the access count to prevent wakeups
while the cache is active. We're only interested in the wakeup when a
cookie is being withdrawn and we're waiting for it to quiesce - at
which point the counter will be decremented before the wait.
The FSCACHE_COOKIE_NACC_ELEVATED flag is set on the cookie to keep
track of the extra ref in order to handle a race between
relinquishment and withdrawal both trying to drop the extra ref.
(2) bool fscache_begin_cookie_access(struct fscache_cookie *cookie,
enum fscache_access_trace why);
This function attempts to begin access upon a cookie, pinning it in
place if it's cached. If successful, it returns true and leaves a the
access count incremented.
(3) void fscache_end_cookie_access(struct fscache_cookie *cookie,
enum fscache_access_trace why);
This function drops the access count obtained by (2), permitting
object withdrawal to take place when it reaches zero.
A tracepoint is provided to track changes to the access counter on a
cookie.
Changes
=======
ver #2:
- Don't hold n_accesses elevated whilst cache is bound to a cookie, but
rather add a flag that prevents the state machine from being queued when
n_accesses reaches 0.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/163819595085.215744.1706073049250505427.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/163906895313.143852.10141619544149102193.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/163967095980.1823006.1133648159424418877.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/164021503063.640689.8870918985269528670.stgit@warthog.procyon.org.uk/ # v4
Signed-off-by: Jeffrey Layton <jlayton@redhat.com>
Bugzilla: http://bugzilla.redhat.com/1229736
commit e6acd3299badbfb5fb0231d42481d4f5dedf5599
Author: David Howells <dhowells@redhat.com>
Date: Wed Oct 20 15:26:17 2021 +0100
fscache: Implement volume-level access helpers
Add a pair of helper functions to manage access to a volume, pinning the
volume in place for the duration to prevent cache withdrawal from removing
it:
bool fscache_begin_volume_access(struct fscache_volume *volume,
enum fscache_access_trace why);
void fscache_end_volume_access(struct fscache_volume *volume,
enum fscache_access_trace why);
The way the access gate on the volume works/will work is:
(1) If the cache tests as not live (state is not FSCACHE_CACHE_IS_ACTIVE),
then we return false to indicate access was not permitted.
(2) If the cache tests as live, then we increment the volume's n_accesses
count and then recheck the cache liveness, ending the access if it
ceased to be live.
(3) When we end the access, we decrement the volume's n_accesses and wake
up the any waiters if it reaches 0.
(4) Whilst the cache is caching, the volume's n_accesses is kept
artificially incremented to prevent wakeups from happening.
(5) When the cache is taken offline, the state is changed to prevent new
accesses, the volume's n_accesses is decremented and we wait for it to
become 0.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/163819594158.215744.8285859817391683254.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/163906894315.143852.5454793807544710479.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/163967095028.1823006.9173132503876627466.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/164021501546.640689.9631510472149608443.stgit@warthog.procyon.org.uk/ # v4
Signed-off-by: Jeffrey Layton <jlayton@redhat.com>
Bugzilla: http://bugzilla.redhat.com/1229736
commit 23e12e285a6ab7320a8bceead29cfe13190a6e3c
Author: David Howells <dhowells@redhat.com>
Date: Wed Oct 20 15:00:26 2021 +0100
fscache: Implement cache-level access helpers
Add a pair of functions to pin/unpin a cache that we're wanting to do a
high-level access to (such as creating or removing a volume):
bool fscache_begin_cache_access(struct fscache_cache *cache,
enum fscache_access_trace why);
void fscache_end_cache_access(struct fscache_cache *cache,
enum fscache_access_trace why);
The way the access gate works/will work is:
(1) If the cache tests as not live (state is not FSCACHE_CACHE_IS_ACTIVE),
then we return false to indicate access was not permitted.
(2) If the cache tests as live, then we increment the n_accesses count and
then recheck the liveness, ending the access if it ceased to be live.
(3) When we end the access, we decrement n_accesses and wake up the any
waiters if it reaches 0.
(4) Whilst the cache is caching, n_accesses is kept artificially
incremented to prevent wakeups from happening.
(5) When the cache is taken offline, the state is changed to prevent new
accesses, n_accesses is decremented and we wait for n_accesses to
become 0.
Note that some of this is implemented in a later patch.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/163819593239.215744.7537428720603638088.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/163906893368.143852.14164004598465617981.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/163967093977.1823006.6967886507023056409.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/164021499995.640689.18286203753480287850.stgit@warthog.procyon.org.uk/ # v4
Signed-off-by: Jeffrey Layton <jlayton@redhat.com>
Bugzilla: http://bugzilla.redhat.com/1229736
commit 7f3283aba39a0f395700c3b5defa4ec49d9914b3
Author: David Howells <dhowells@redhat.com>
Date: Wed Oct 20 15:53:34 2021 +0100
fscache: Implement cookie registration
Add functions to the fscache API to allow data file cookies to be acquired
and relinquished by the network filesystem. It is intended that the
filesystem will create such cookies per-inode under a volume.
To request a cookie, the filesystem should call:
struct fscache_cookie *
fscache_acquire_cookie(struct fscache_volume *volume,
u8 advice,
const void *index_key,
size_t index_key_len,
const void *aux_data,
size_t aux_data_len,
loff_t object_size)
The filesystem must first have created a volume cookie, which is passed in
here. If it passes in NULL then the function will just return a NULL
cookie.
A binary key should be passed in index_key and is of size index_key_len.
This is saved in the cookie and is used to locate the associated data in
the cache.
A coherency data buffer of size aux_data_len will be allocated and
initialised from the buffer pointed to by aux_data. This is used to
validate cache objects when they're opened and is stored on disk with them
when they're committed. The data is stored in the cookie and will be
updateable by various functions in later patches.
The object_size must also be given. This is also used to perform a
coherency check and to size the backing storage appropriately.
This function disallows a cookie from being acquired twice in parallel,
though it will cause the second user to wait if the first is busy
relinquishing its cookie.
When a network filesystem has finished with a cookie, it should call:
void
fscache_relinquish_cookie(struct fscache_volume *volume,
bool retire)
If retire is true, any backing data will be discarded immediately.
Changes
=======
ver #3:
- fscache_hash()'s size parameter is now in bytes. Use __le32 as the unit
to round up to.
- When comparing cookies, simply see if the attributes are the same rather
than subtracting them to produce a strcmp-style return[1].
- Add a check to see if the cookie is still hashed at the point of
freeing.
ver #2:
- Don't hold n_accesses elevated whilst cache is bound to a cookie, but
rather add a flag that prevents the state machine from being queued when
n_accesses reaches 0.
- Remove the unused cookie pointer field from the fscache_acquire
tracepoint.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/CAHk-=whtkzB446+hX0zdLsdcUJsJ=8_-0S1mE_R+YurThfUbLA@mail.gmail.com/ [1]
Link: https://lore.kernel.org/r/163819590658.215744.14934902514281054323.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/163906891983.143852.6219772337558577395.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/163967088507.1823006.12659006350221417165.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/164021498432.640689.12743483856927722772.stgit@warthog.procyon.org.uk/ # v4
Signed-off-by: Jeffrey Layton <jlayton@redhat.com>
Bugzilla: http://bugzilla.redhat.com/1229736
commit 62ab63352350e881ae693a8236b35d7d0516c78b
Author: David Howells <dhowells@redhat.com>
Date: Wed Oct 20 15:26:17 2021 +0100
fscache: Implement volume registration
Add functions to the fscache API to allow volumes to be acquired and
relinquished by the network filesystem. A volume is an index of data
storage cache objects. A volume is represented by a volume cookie in the
API. A filesystem would typically create a volume for a superblock and
then create per-inode cookies within it.
To request a volume, the filesystem calls:
struct fscache_volume *
fscache_acquire_volume(const char *volume_key,
const char *cache_name,
const void *coherency_data,
size_t coherency_len)
The volume_key is a printable string used to match the volume in the cache.
It should not contain any '/' characters. For AFS, for example, this would
be "afs,<cellname>,<volume_id>", e.g. "afs,example.com,523001".
The cache_name can be NULL, but if not it should be a string indicating the
name of the cache to use if there's more than one available.
The coherency data, if given, is an arbitrarily-sized blob that's attached
to the volume and is compared when the volume is looked up. If it doesn't
match, the old volume is judged to be out of date and it and everything
within it is discarded.
Acquiring a volume twice concurrently is disallowed, though the function
will wait if an old volume cookie is being relinquishing.
When a network filesystem has finished with a volume, it should return the
volume cookie by calling:
void
fscache_relinquish_volume(struct fscache_volume *volume,
const void *coherency_data,
bool invalidate)
If invalidate is true, the entire volume will be discarded; if false, the
volume will be synced and the coherency data will be updated.
Changes
=======
ver #4:
- Removed an extraneous param from kdoc on fscache_relinquish_volume()[3].
ver #3:
- fscache_hash()'s size parameter is now in bytes. Use __le32 as the unit
to round up to.
- When comparing cookies, simply see if the attributes are the same rather
than subtracting them to produce a strcmp-style return[2].
- Make the coherency data an arbitrary blob rather than a u64, but don't
store it for the moment.
ver #2:
- Fix error check[1].
- Make a fscache_acquire_volume() return errors, including EBUSY if a
conflicting volume cookie already exists. No error is printed now -
that's left to the netfs.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/20211203095608.GC2480@kili/ [1]
Link: https://lore.kernel.org/r/CAHk-=whtkzB446+hX0zdLsdcUJsJ=8_-0S1mE_R+YurThfUbLA@mail.gmail.com/ [2]
Link: https://lore.kernel.org/r/20211220224646.30e8205c@canb.auug.org.au/ [3]
Link: https://lore.kernel.org/r/163819588944.215744.1629085755564865996.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/163906890630.143852.13972180614535611154.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/163967086836.1823006.8191672796841981763.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/164021495816.640689.4403156093668590217.stgit@warthog.procyon.org.uk/ # v4
Signed-off-by: Jeffrey Layton <jlayton@redhat.com>
Bugzilla: http://bugzilla.redhat.com/1229736
commit 20ec197bfa13c5b799fc9527790ea7b5374fc8f2
Author: David Howells <dhowells@redhat.com>
Date: Mon Mar 29 13:53:50 2021 +0100
fscache: Use refcount_t for the cookie refcount instead of atomic_t
Use refcount_t for the fscache_cookie refcount instead of atomic_t and
rename the 'usage' member to 'ref' in such cases. The tracepoints that
reference it change from showing "u=%d" to "r=%d".
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/162431204358.2908479.8006938388213098079.stgit@warthog.procyon.org.uk/
Signed-off-by: Jeffrey Layton <jlayton@redhat.com>
Bugzilla: http://bugzilla.redhat.com/1229736
commit 33cba859220b0878b3b2931caa1629a3d2432379
Author: David Howells <dhowells@redhat.com>
Date: Fri Jun 18 11:19:49 2021 +0100
fscache: Fix fscache_cookie_put() to not deref after dec
fscache_cookie_put() accesses the cookie it has just put inside the
tracepoint that monitors the change - but this is something it's not
allowed to do if we didn't reduce the count to zero.
Fix this by dropping most of those values from the tracepoint and grabbing
the cookie debug ID before doing the dec.
Also take the opportunity to switch over the usage and where arguments on
the tracepoint to put the reason last.
Fixes: a18feb5576 ("fscache: Add tracepoints")
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/162431203107.2908479.3259582550347000088.stgit@warthog.procyon.org.uk/
Signed-off-by: Jeffrey Layton <jlayton@redhat.com>
Rado Vrbovsky
CKI Backport Bot
Pavel Reichl
Baoquan He
Chris von Recklinghausen
Jeffrey Layton