This patch changes the handling of a plock operation that was interrupted
while waiting for a user space reply from dlm_controld. (This is not
the lock blocking state, i.e. locks_lock_file_wait().)
Currently, when an op is interrupted while waiting on user space, the
op is removed. When the user space result later arrives, a kernel
message is loggged: "dev_write no op...". This can be seen from a test
such as "stress-ng --fcntl 100" and interrupting it with ctrl-c.
Now, leave the op in place when interrupted and remove it when the
result arrives (the result will be ignored.) With this change, the
logged message is not expected to appear, and would indicate a bug.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch refactors do_unlock_close() by using only struct dlm_plock_info
as a parameter.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch reverses the commit bcfad4265c ("dlm: improve plock logging
if interrupted") by moving it to debug level and notifying the user an op
was removed.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch adds the pid information which requested the lock operation
to the debug log output.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch will use the list helper list_first_entry() instead of using
list_entry() to get the first element of a list.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch will optimize __put_lkb() by using kref_put_lock(). The
function kref_put_lock() will only take the lock if the reference is
going to be zero, if not the lock will never be held.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch will optimize put_rsb() by using kref_put_lock(). The
function kref_put_lock() will only take the lock if the reference is
going to be zero, if not the lock will never be held.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch removes unnecessary error assigns to 0 at places we know that
error is zero because it was checked on non-zero before.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
We always call hold_lkb(lkb) if we increment lkb->lkb_wait_count.
So, we always need to call unhold_lkb(lkb) if we decrement
lkb->lkb_wait_count. This patch will add missing unhold_lkb(lkb) if we
decrement lkb->lkb_wait_count. In case of setting lkb->lkb_wait_count to
zero we need to countdown until reaching zero and call unhold_lkb(lkb).
The waiters list unhold_lkb(lkb) can be removed because it's done for
the last lkb_wait_count decrement iteration as it's done in
_remove_from_waiters().
This issue was discovered by a dlm gfs2 test case which use excessively
dlm_unlock(LKF_CANCEL) feature. Probably the lkb->lkb_wait_count value
never reached above 1 if this feature isn't used and so it was not
discovered before.
The testcase ended in a rsb on the rsb keep data structure with a
refcount of 1 but no lkb was associated with it, which is itself
an invalid behaviour. A side effect of that was a condition in which
the dlm was sending remove messages in a looping behaviour. With this
patch that has not been reproduced.
Cc: stable@vger.kernel.org
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch fixes the following warning when doing a 32 bit kernel build
when pointers are 4 byte long:
In file included from ./include/linux/byteorder/little_endian.h:5,
from ./arch/x86/include/uapi/asm/byteorder.h:5,
from ./include/asm-generic/qrwlock_types.h:6,
from ./arch/x86/include/asm/spinlock_types.h:7,
from ./include/linux/spinlock_types_raw.h:7,
from ./include/linux/ratelimit_types.h:7,
from ./include/linux/printk.h:10,
from ./include/asm-generic/bug.h:22,
from ./arch/x86/include/asm/bug.h:87,
from ./include/linux/bug.h:5,
from ./include/linux/mmdebug.h:5,
from ./include/linux/gfp.h:5,
from ./include/linux/slab.h:15,
from fs/dlm/dlm_internal.h:19,
from fs/dlm/rcom.c:12:
fs/dlm/rcom.c: In function ‘dlm_send_rcom_lock’:
./include/uapi/linux/byteorder/little_endian.h:32:43: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
#define __cpu_to_le64(x) ((__force __le64)(__u64)(x))
^
./include/linux/byteorder/generic.h:86:21: note: in expansion of macro ‘__cpu_to_le64’
#define cpu_to_le64 __cpu_to_le64
^~~~~~~~~~~~~
fs/dlm/rcom.c:457:14: note: in expansion of macro ‘cpu_to_le64’
rc->rc_id = cpu_to_le64(r);
The rc_id value in dlm rcom is handled as u64. The rcom implementation
uses for an unique number generation the pointer value of the used
dlm_rsb instance. However if the pointer value is 4 bytes long
-Wpointer-to-int-cast will print a warning. We get rid of that warning
to cast the pointer to uintptr_t which is either 4 or 8 bytes. There
might be a very unlikely case where this number isn't unique anymore if
using dlm in a mixed cluster of nodes and sizeof(uintptr_t) returns 4 and
8.
However this problem was already been there and this patch should get
rid of the warning.
Fixes: 2f9dbeda8d ("dlm: use __le types for rcom messages")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
To move the list iterator variable into the list_for_each_entry_*()
macro in the future it should be avoided to use the list iterator
variable after the loop body.
To *never* use the list iterator variable after the loop it was
concluded to use a separate iterator variable instead of a
found boolean [1].
This removes the need to use a found variable and simply checking if
the variable was set, can determine if the break/goto was hit.
Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1]
Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
In preparation to limit the scope of a list iterator to the list
traversal loop, use a dedicated pointer to point to the found element [1].
Before, the code implicitly used the head when no element was found
when using &pos->list. Since the new variable is only set if an
element was found, the list_add() is performed within the loop
and only done after the loop if it is done on the list head directly.
Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1]
Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch unsets ls_remove_len and ls_remove_name if a message
allocation of a remove messages fails. In this case we never send a
remove message out but set the per ls ls_remove_len ls_remove_name
variable for a pending remove. Unset those variable should indicate
possible waiters in wait_pending_remove() that no pending remove is
going on at this moment.
Cc: stable@vger.kernel.org
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch move the wake_up() call at the point when a remove message
completed. Before it was only when a remove message was going to be
sent. The possible waiter in wait_pending_remove() waits until a remove
is done if the resource name matches with the per ls variable
ls->ls_remove_name. If this is the case we must wait until a pending
remove is done which is indicated if DLM_WAIT_PENDING_COND() returns
false which will always be the case when ls_remove_len and
ls_remove_name are unset to indicate that a remove is not going on
anymore.
Fixes: 21d9ac1a53 ("fs: dlm: use event based wait for pending remove")
Cc: stable@vger.kernel.org
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch adds a WARN_ON() check to validate the right context while
dlm_midcomms_close() is called. Even before commit 489d8e559c
("fs: dlm: add reliable connection if reconnect") in this context
dlm_lowcomms_close() flushes all ongoing transmission triggered by dlm
application stack. If we do that, it's required that no new message will
be triggered by the dlm application stack. The function
dlm_midcomms_close() is not called often so we can check if all
lockspaces are in such context.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch will remove the following warning by sparse:
fs/dlm/lock.c:1049:9: warning: context imbalance in 'dlm_master_lookup' - different lock contexts for basic block
I tried to find any issues with the current handling and I did not find
any. However it is hard to follow the lock handling in this area of
dlm_master_lookup() and I suppose that sparse cannot realize that there
are no issues. The variable "toss_list" makes it really hard to follow
the lock handling because if it's set the rsb lock/refcount isn't held
but the ls->ls_rsbtbl[b].lock is held and this is one reason why the rsb
lock/refcount does not need to be held. If it's not set the
ls->ls_rsbtbl[b].lock is not held but the rsb lock/refcount is held. The
indicator of toss_list will be used to store the actual lock state.
Another possibility is that a retry can happen and then it's hard to
follow the specific code part. I did not find any issues but sparse
cannot realize that there are no issues.
To make it more easier to understand for developers and sparse as well,
we remove the toss_list variable which indicates a specific lock state
and move handling in between of this lock state in a separate function.
This function can be called now in case when the initial lock states are
taken which was previously signalled if toss_list was set or not. The
advantage here is that we can release all locks/refcounts in mostly the
same code block as it was taken.
Afterwards sparse had no issues to figure out that there are no problems
with the current lock behaviour.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch cleanups a not necessary label found which can be replaced by
a proper else handling to jump over a specific code block.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch avoids the following sparse warning:
fs/dlm/user.c:111:38: warning: incorrect type in assignment (different address spaces)
fs/dlm/user.c:111:38: expected void [noderef] __user *castparam
fs/dlm/user.c:111:38: got void *
fs/dlm/user.c:112:37: warning: incorrect type in assignment (different address spaces)
fs/dlm/user.c:112:37: expected void [noderef] __user *castaddr
fs/dlm/user.c:112:37: got void *
fs/dlm/user.c:113:38: warning: incorrect type in assignment (different address spaces)
fs/dlm/user.c:113:38: expected void [noderef] __user *bastparam
fs/dlm/user.c:113:38: got void *
fs/dlm/user.c:114:37: warning: incorrect type in assignment (different address spaces)
fs/dlm/user.c:114:37: expected void [noderef] __user *bastaddr
fs/dlm/user.c:114:37: got void *
fs/dlm/user.c:115:33: warning: incorrect type in assignment (different address spaces)
fs/dlm/user.c:115:33: expected struct dlm_lksb [noderef] __user *lksb
fs/dlm/user.c:115:33: got void *
fs/dlm/user.c:130:39: warning: cast removes address space '__user' of expression
fs/dlm/user.c:131:40: warning: cast removes address space '__user' of expression
fs/dlm/user.c:132:36: warning: cast removes address space '__user' of expression
So far I see there is no direct handling of copying a pointer value to
another pointer value. The handling only copies the actual pointer
address to a scalar type or vice versa. This should be okay because it
never handles dereferencing anything of those addresses in the kernel
space. To get rid of those warnings we doing some different casting
which results in no warnings in sparse or compiler.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch is a cleanup to move the byte order conversion to compile
time. In a simple comparison like this it's possible to move it to
static values so the compiler will always convert those values at
compile time.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch changes to use __le types directly in the dlm message
structure which is casted at the right dlm message buffer positions.
The main goal what is reached here is to remove sparse warnings
regarding to host to little byte order conversion or vice versa. Leaving
those sparse issues ignored and always do it in out/in functionality
tends to leave it unknown in which byte order the variable is being
handled.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch changes to use __le types directly in the dlm rcom
structure which is casted at the right dlm message buffer positions.
The main goal what is reached here is to remove sparse warnings
regarding to host to little byte order conversion or vice versa. Leaving
those sparse issues ignored and always do it in out/in functionality
tends to leave it unknown in which byte order the variable is being
handled.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch changes to use __le types directly in the dlm header
structure which is casted at the right dlm message buffer positions.
The main goal what is reached here is to remove sparse warnings
regarding to host to little byte order conversion or vice versa. Leaving
those sparse issues ignored and always do it in out/in functionality
tends to leave it unknown in which byte order the variable is being
handled.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch changes to use __le types directly in the dlm option headers
structures which are casted at the right dlm message buffer positions.
Currently only midcomms.c using those headers which already was calling
endian conversions on-the-fly without using in/out functionality like
other endianness handling in dlm. Using __le types now will hopefully get
useful warnings in future if we do comparison against host byte order
values.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch will adds #ifndef __CHECKER__ for false positives warnings
about an imbalance lock/unlock srcu handling. Which are shown by running
sparse checks:
fs/dlm/midcomms.c:1065:20: warning: context imbalance in 'dlm_midcomms_get_mhandle' - wrong count at exit
Using __CHECKER__ will tell sparse to ignore these sections.
Those imbalances are false positive because from upper layer it is
always required to call a function in sequence, e.g. if
dlm_midcomms_get_mhandle() is successful there must be a
dlm_midcomms_commit_mhandle() call afterwards.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
Instead of init global module at module loading time we can move the
initialization of those global variables at memory initialization of the
module loader.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
There is no need to call INIT_LIST_HEAD() when it's set directly
afterwards by list_add_tail().
Reported-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch changes the log level if a plock is removed when interrupted
from debug to info. Additional it signals now that the plock entity was
removed to let the user know what's happening.
If on a dev_write() a pending plock cannot be find it will signal that
it might have been removed because wait interruption.
Before this patch there might be a "dev_write no op ..." info message
and the users can only guess that the plock was removed before because
the wait interruption. To be sure that is the case we log both messages
on the same log level.
Let both message be logged on info layer because it should not happened
a lot and if it happens it should be clear why the op was not found.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch moves the return of FILE_LOCK_DEFERRED a little bit earlier
than checking afterwards again if the request was an asynchronous request.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
Lately the different casting between plock_op and plock_xop and list
holders which was involved showed some issues which were hard to see.
This patch removes the "plock_xop" structure and introduces a
"struct plock_async_data". This structure will be set in "struct plock_op"
in case of asynchronous lock handling as the original "plock_xop" was
made for. There is no need anymore to cast pointers around for
additional fields in case of asynchronous lock handling. As disadvantage
another allocation was introduces but only needed in the asynchronous
case which is currently only used in combination with nfs lockd.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
There are several sanity checks and recover handling if they occur in
the dlm plock handling. From my understanding those operation can't run
in parallel with any list manipulation which involved setting the list
holder of plock_op, if so we have a bug which this sanity check will
warn about. Previously if such sanity check occurred the dlm plock
handling was trying to recover from it by deleting the plock_op from a
list which the holder was set to. However there is a bug in the dlm
plock handling if this case ever happens. To make such bugs are more
visible for further investigations we add a WARN_ON() on those sanity
checks and remove the recovering handling because other possible side
effects.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch adds a additional check if lkb->lkb_wait_count is non zero as
it is done in validate_unlock_args() to check if any operation is in
progress. While on it add a comment taken from validate_unlock_args() to
signal what the check is doing.
There might be no changes because if lkb->lkb_wait_type is non zero
implies that lkb->lkb_wait_count is non zero. However we should add the
check as it does validate_unlock_args().
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
The "sock" variable is not initialized on this error path.
Cc: stable@vger.kernel.org
Fixes: 2dc6b1158c ("fs: dlm: introduce generic listen")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
Here is the set of changes for the driver core for 5.17-rc1.
Lots of little things here, including:
- kobj_type cleanups
- auxiliary_bus documentation updates
- auxiliary_device conversions for some drivers (relevant
subsystems all have provided acks for these)
- kernfs lock contention reduction for some workloads
- other tiny cleanups and changes.
All of these have been in linux-next for a while with no reported
issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core updates from Greg KH:
"Here is the set of changes for the driver core for 5.17-rc1.
Lots of little things here, including:
- kobj_type cleanups
- auxiliary_bus documentation updates
- auxiliary_device conversions for some drivers (relevant subsystems
all have provided acks for these)
- kernfs lock contention reduction for some workloads
- other tiny cleanups and changes.
All of these have been in linux-next for a while with no reported
issues"
* tag 'driver-core-5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (43 commits)
kobject documentation: remove default_attrs information
drivers/firmware: Add missing platform_device_put() in sysfb_create_simplefb
debugfs: lockdown: Allow reading debugfs files that are not world readable
driver core: Make bus notifiers in right order in really_probe()
driver core: Move driver_sysfs_remove() after driver_sysfs_add()
firmware: edd: remove empty default_attrs array
firmware: dmi-sysfs: use default_groups in kobj_type
qemu_fw_cfg: use default_groups in kobj_type
firmware: memmap: use default_groups in kobj_type
sh: sq: use default_groups in kobj_type
headers/uninline: Uninline single-use function: kobject_has_children()
devtmpfs: mount with noexec and nosuid
driver core: Simplify async probe test code by using ktime_ms_delta()
nilfs2: use default_groups in kobj_type
kobject: remove kset from struct kset_uevent_ops callbacks
driver core: make kobj_type constant.
driver core: platform: document registration-failure requirement
vdpa/mlx5: Use auxiliary_device driver data helpers
net/mlx5e: Use auxiliary_device driver data helpers
soundwire: intel: Use auxiliary_device driver data helpers
...
This patch prints the cluster node address if a non-cluster node
(according to the dlm config setting) tries to connect. The current
hexdump call will print in a different loglevel and only available if
dynamic debug is enabled. Additional we using the ip address format
strings to print an IETF ip4/6 string represenation.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
There is no need to pass the pointer to the kset in the struct
kset_uevent_ops callbacks as no one uses it, so just remove that pointer
entirely.
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Wedson Almeida Filho <wedsonaf@google.com>
Link: https://lore.kernel.org/r/20211227163924.3970661-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch introduces a kmem cache for dlm_msg handles which are used
always if dlm sends a message out. Even if their are covered by midcomms
layer or not.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch introduces a kmem cache for writequeue entry. A writequeue
entry get quite a lot allocated if dlm transmit messages.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch will introduce a kmem cache for allocating message handles
which are needed for midcomms layer to take track of lowcomms messages.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch cleanups the code for allocating a new buffer in the dlm
writequeue mechanism. There was a possible tuneup to allow scheduling
while a new writequeue entry needs to be allocated because either no
sending page is available or are full. To avoid multiple concurrent
users checking at the same time if an entry is available or full
alloc_wq was introduce that those are waiting if there is currently a
new writequeue entry in process to be queued so possible further users
will check on the new allocated writequeue entry if it's full.
To simplify the code we just remove this mutex and switch that the
already introduced spin lock will be held during writequeue check,
allocation and queueing. So other users can never check on available
writequeues while there is a new one in process but not queued yet.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch will use an event based waitqueue to wait for a possible clash
with the ls_remove_name field of dlm_ls instead of doing busy waiting.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
Currently we don't care if the DLM application stack is filling buffers
(not committed yet) while we transmit some already committed buffers.
By checking on active writequeue users before dequeue a writequeue entry
we know there is coming more data and do nothing. We wait until the send
worker will be triggered again if the writequeue entry users hit zero.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch will use list_empty(&ls->ls_cb_delay) to check for last list
iteration. In case of a multiply count of MAX_CB_QUEUE and the list is
empty we do a extra goto more which we can avoid by checking on
list_empty().
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch will surround the AF_INET6 case in sk_error_report() of dlm
with a #if IS_ENABLED(CONFIG_IPV6). The field sk->sk_v6_daddr is not
defined when CONFIG_IPV6 is disabled. If CONFIG_IPV6 is disabled, the
socket creation with AF_INET6 should already fail because a runtime
check if AF_INET6 is registered. However if there is the possibility
that AF_INET6 is set as sk_family the sk_error_report() callback will
print then an invalid family type error.
Reported-by: kernel test robot <lkp@intel.com>
Fixes: 4c3d90570b ("fs: dlm: don't call kernel_getpeername() in error_report()")
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch will replace the use of socket sk_callback_lock lock and uses
socket lock instead. Some users like sunrpc, see commit ea9afca88b
("SUNRPC: Replace use of socket sk_callback_lock with sock_lock") moving
from sk_callback_lock to sock_lock which seems to be held when the socket
callbacks are called.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
In some cases kernel_getpeername() will held the socket lock which is
already held when the socket layer calls error_report() callback. Since
commit 9dfc685e02 ("inet: remove races in inet{6}_getname()") this
problem becomes more likely because the socket lock will be held always.
You will see something like:
bob9-u5 login: [ 562.316860] BUG: spinlock recursion on CPU#7, swapper/7/0
[ 562.318562] lock: 0xffff8f2284720088, .magic: dead4ead, .owner: swapper/7/0, .owner_cpu: 7
[ 562.319522] CPU: 7 PID: 0 Comm: swapper/7 Not tainted 5.15.0+ #135
[ 562.320346] Hardware name: Red Hat KVM/RHEL-AV, BIOS 1.13.0-2.module+el8.3.0+7353+9de0a3cc 04/01/2014
[ 562.321277] Call Trace:
[ 562.321529] <IRQ>
[ 562.321734] dump_stack_lvl+0x33/0x42
[ 562.322282] do_raw_spin_lock+0x8b/0xc0
[ 562.322674] lock_sock_nested+0x1e/0x50
[ 562.323057] inet_getname+0x39/0x110
[ 562.323425] ? sock_def_readable+0x80/0x80
[ 562.323838] lowcomms_error_report+0x63/0x260 [dlm]
[ 562.324338] ? wait_for_completion_interruptible_timeout+0xd2/0x120
[ 562.324949] ? lock_timer_base+0x67/0x80
[ 562.325330] ? do_raw_spin_unlock+0x49/0xc0
[ 562.325735] ? _raw_spin_unlock_irqrestore+0x1e/0x40
[ 562.326218] ? del_timer+0x54/0x80
[ 562.326549] sk_error_report+0x12/0x70
[ 562.326919] tcp_validate_incoming+0x3c8/0x530
[ 562.327347] ? kvm_clock_read+0x14/0x30
[ 562.327718] ? ktime_get+0x3b/0xa0
[ 562.328055] tcp_rcv_established+0x121/0x660
[ 562.328466] tcp_v4_do_rcv+0x132/0x260
[ 562.328835] tcp_v4_rcv+0xcea/0xe20
[ 562.329173] ip_protocol_deliver_rcu+0x35/0x1f0
[ 562.329615] ip_local_deliver_finish+0x54/0x60
[ 562.330050] ip_local_deliver+0xf7/0x110
[ 562.330431] ? inet_rtm_getroute+0x211/0x840
[ 562.330848] ? ip_protocol_deliver_rcu+0x1f0/0x1f0
[ 562.331310] ip_rcv+0xe1/0xf0
[ 562.331603] ? ip_local_deliver+0x110/0x110
[ 562.332011] __netif_receive_skb_core+0x46a/0x1040
[ 562.332476] ? inet_gro_receive+0x263/0x2e0
[ 562.332885] __netif_receive_skb_list_core+0x13b/0x2c0
[ 562.333383] netif_receive_skb_list_internal+0x1c8/0x2f0
[ 562.333896] ? update_load_avg+0x7e/0x5e0
[ 562.334285] gro_normal_list.part.149+0x19/0x40
[ 562.334722] napi_complete_done+0x67/0x160
[ 562.335134] virtnet_poll+0x2ad/0x408 [virtio_net]
[ 562.335644] __napi_poll+0x28/0x140
[ 562.336012] net_rx_action+0x23d/0x300
[ 562.336414] __do_softirq+0xf2/0x2ea
[ 562.336803] irq_exit_rcu+0xc1/0xf0
[ 562.337173] common_interrupt+0xb9/0xd0
It is and was always forbidden to call kernel_getpeername() in context
of error_report(). To get rid of the problem we access the destination
address for the peer over the socket structure. While on it we fix to
print out the destination port of the inet socket.
Fixes: 1a31833d08 ("DLM: Replace nodeid_to_addr with kernel_getpeername")
Reported-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch fixes an potential overflow in sscanf and the maximum
declared string parsing length which seems to be excluding the null
termination symbol. This patch will just add one byte to be prepared on
a string with length of DLM_RESNAME_MAXLEN including the null
termination symbol.
Fixes: 5054e79de9 ("fs: dlm: add lkb debugfs functionality")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch removes a list_first_entry() call which is already done by
the previous con_next_wq() call.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This patch fixes the following crash by receiving a invalid message:
[ 160.672220] ==================================================================
[ 160.676206] BUG: KASAN: user-memory-access in dlm_user_add_ast+0xc3/0x370
[ 160.679659] Read of size 8 at addr 00000000deadbeef by task kworker/u32:13/319
[ 160.681447]
[ 160.681824] CPU: 10 PID: 319 Comm: kworker/u32:13 Not tainted 5.14.0-rc2+ #399
[ 160.683472] Hardware name: Red Hat KVM/RHEL-AV, BIOS 1.14.0-1.module+el8.6.0+12648+6ede71a5 04/01/2014
[ 160.685574] Workqueue: dlm_recv process_recv_sockets
[ 160.686721] Call Trace:
[ 160.687310] dump_stack_lvl+0x56/0x6f
[ 160.688169] ? dlm_user_add_ast+0xc3/0x370
[ 160.689116] kasan_report.cold.14+0x116/0x11b
[ 160.690138] ? dlm_user_add_ast+0xc3/0x370
[ 160.690832] dlm_user_add_ast+0xc3/0x370
[ 160.691502] _receive_unlock_reply+0x103/0x170
[ 160.692241] _receive_message+0x11df/0x1ec0
[ 160.692926] ? rcu_read_lock_sched_held+0xa1/0xd0
[ 160.693700] ? rcu_read_lock_bh_held+0xb0/0xb0
[ 160.694427] ? lock_acquire+0x175/0x400
[ 160.695058] ? do_purge.isra.51+0x200/0x200
[ 160.695744] ? lock_acquired+0x360/0x5d0
[ 160.696400] ? lock_contended+0x6a0/0x6a0
[ 160.697055] ? lock_release+0x21d/0x5e0
[ 160.697686] ? lock_is_held_type+0xe0/0x110
[ 160.698352] ? lock_is_held_type+0xe0/0x110
[ 160.699026] ? ___might_sleep+0x1cc/0x1e0
[ 160.699698] ? dlm_wait_requestqueue+0x94/0x140
[ 160.700451] ? dlm_process_requestqueue+0x240/0x240
[ 160.701249] ? down_write_killable+0x2b0/0x2b0
[ 160.701988] ? do_raw_spin_unlock+0xa2/0x130
[ 160.702690] dlm_receive_buffer+0x1a5/0x210
[ 160.703385] dlm_process_incoming_buffer+0x726/0x9f0
[ 160.704210] receive_from_sock+0x1c0/0x3b0
[ 160.704886] ? dlm_tcp_shutdown+0x30/0x30
[ 160.705561] ? lock_acquire+0x175/0x400
[ 160.706197] ? rcu_read_lock_sched_held+0xa1/0xd0
[ 160.706941] ? rcu_read_lock_bh_held+0xb0/0xb0
[ 160.707681] process_recv_sockets+0x32/0x40
[ 160.708366] process_one_work+0x55e/0xad0
[ 160.709045] ? pwq_dec_nr_in_flight+0x110/0x110
[ 160.709820] worker_thread+0x65/0x5e0
[ 160.710423] ? process_one_work+0xad0/0xad0
[ 160.711087] kthread+0x1ed/0x220
[ 160.711628] ? set_kthread_struct+0x80/0x80
[ 160.712314] ret_from_fork+0x22/0x30
The issue is that we received a DLM message for a user lock but the
destination lock is a kernel lock. Note that the address which is trying
to derefence is 00000000deadbeef, which is in a kernel lock
lkb->lkb_astparam, this field should never be derefenced by the DLM
kernel stack. In case of a user lock lkb->lkb_astparam is lkb->lkb_ua
(memory is shared by a union field). The struct lkb_ua will be handled
by the DLM kernel stack but on a kernel lock it will contain invalid
data and ends in most likely crashing the kernel.
It can be reproduced with two cluster nodes.
node 2:
dlm_tool join test
echo "862 fooobaar 1 2 1" > /sys/kernel/debug/dlm/test_locks
echo "862 3 1" > /sys/kernel/debug/dlm/test_waiters
node 1:
dlm_tool join test
python:
foo = DLM(h_cmd=3, o_nextcmd=1, h_nodeid=1, h_lockspace=0x77222027, \
m_type=7, m_flags=0x1, m_remid=0x862, m_result=0xFFFEFFFE)
newFile = open("/sys/kernel/debug/dlm/comms/2/rawmsg", "wb")
newFile.write(bytes(foo))
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
