linux-stable.git/fs/dlm, branch v5.4.263

dlm: fix plock lookup when using multiple lockspaces

2023-09-23T08:59:55+00:00

commit 7c53e847ff5e97f033fdd31f71949807633d506b upstream.

All posix lock ops, for all lockspaces (gfs2 file systems) are
sent to userspace (dlm_controld) through a single misc device.
The dlm_controld daemon reads the ops from the misc device
and sends them to other cluster nodes using separate, per-lockspace
cluster api communication channels.  The ops for a single lockspace
are ordered at this level, so that the results are received in
the same sequence that the requests were sent.  When the results
are sent back to the kernel via the misc device, they are again
funneled through the single misc device for all lockspaces.  When
the dlm code in the kernel processes the results from the misc
device, these results will be returned in the same sequence that
the requests were sent, on a per-lockspace basis.  A recent change
in this request/reply matching code missed the "per-lockspace"
check (fsid comparison) when matching request and reply, so replies
could be incorrectly matched to requests from other lockspaces.

Cc: stable@vger.kernel.org
Reported-by: Barry Marson 
Fixes: 57e2c2f2d94c ("fs: dlm: fix mismatch of plock results from userspace")
Signed-off-by: Alexander Aring 
Signed-off-by: David Teigland 
Signed-off-by: Greg Kroah-Hartman

fs: dlm: fix mismatch of plock results from userspace

2023-08-30T14:27:21+00:00

[ Upstream commit 57e2c2f2d94cfd551af91cedfa1af6d972487197 ]

When a waiting plock request (F_SETLKW) is sent to userspace
for processing (dlm_controld), the result is returned at a
later time. That result could be incorrectly matched to a
different waiting request in cases where the owner field is
the same (e.g. different threads in a process.) This is fixed
by comparing all the properties in the request and reply.

The results for non-waiting plock requests are now matched
based on list order because the results are returned in the
same order they were sent.

Cc: stable@vger.kernel.org
Signed-off-by: Alexander Aring 
Signed-off-by: David Teigland 
Signed-off-by: Sasha Levin

fs: dlm: use dlm_plock_info for do_unlock_close

2023-08-30T14:27:21+00:00

[ Upstream commit 4d413ae9ced4180c0e2114553c3a7560b509b0f8 ]

This patch refactors do_unlock_close() by using only struct dlm_plock_info
as a parameter.

Signed-off-by: Alexander Aring 
Signed-off-by: David Teigland 
Stable-dep-of: 57e2c2f2d94c ("fs: dlm: fix mismatch of plock results from userspace")
Signed-off-by: Sasha Levin

fs: dlm: change plock interrupted message to debug again

2023-08-30T14:27:20+00:00

[ Upstream commit ea06d4cabf529eefbe7e89e3a8325f1f89355ccd ]

This patch reverses the commit bcfad4265ced ("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 
Signed-off-by: David Teigland 
Stable-dep-of: 57e2c2f2d94c ("fs: dlm: fix mismatch of plock results from userspace")
Signed-off-by: Sasha Levin

fs: dlm: add pid to debug log

2023-08-30T14:27:20+00:00

[ Upstream commit 19d7ca051d303622c423b4cb39e6bde5d177328b ]

This patch adds the pid information which requested the lock operation
to the debug log output.

Signed-off-by: Alexander Aring 
Signed-off-by: David Teigland 
Stable-dep-of: 57e2c2f2d94c ("fs: dlm: fix mismatch of plock results from userspace")
Signed-off-by: Sasha Levin

dlm: replace usage of found with dedicated list iterator variable

2023-08-30T14:27:20+00:00

[ Upstream commit dc1acd5c94699389a9ed023e94dd860c846ea1f6 ]

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 
Signed-off-by: Alexander Aring 
Signed-off-by: David Teigland 
Stable-dep-of: 57e2c2f2d94c ("fs: dlm: fix mismatch of plock results from userspace")
Signed-off-by: Sasha Levin

dlm: improve plock logging if interrupted

2023-08-30T14:27:20+00:00

[ Upstream commit bcfad4265cedf3adcac355e994ef9771b78407bd ]

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 
Signed-off-by: David Teigland 
Stable-dep-of: 57e2c2f2d94c ("fs: dlm: fix mismatch of plock results from userspace")
Signed-off-by: Sasha Levin

fs: dlm: interrupt posix locks only when process is killed

2023-08-11T09:53:45+00:00

[ Upstream commit 59e45c758ca1b9893ac923dd63536da946ac333b ]

If a posix lock request is waiting for a result from user space
(dlm_controld), do not let it be interrupted unless the process
is killed. This reverts commit a6b1533e9a57 ("dlm: make posix locks
interruptible"). The problem with the interruptible change is
that all locks were cleared on any signal interrupt. If a signal
was received that did not terminate the process, the process
could continue running after all its dlm posix locks had been
cleared. A future patch will add cancelation to allow proper
interruption.

Cc: stable@vger.kernel.org
Fixes: a6b1533e9a57 ("dlm: make posix locks interruptible")
Signed-off-by: Alexander Aring 
Signed-off-by: David Teigland 
Signed-off-by: Sasha Levin

dlm: rearrange async condition return

2023-08-11T09:53:45+00:00

[ Upstream commit a800ba77fd285c6391a82819867ac64e9ab3af46 ]

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 
Signed-off-by: David Teigland 
Stable-dep-of: 59e45c758ca1 ("fs: dlm: interrupt posix locks only when process is killed")
Signed-off-by: Sasha Levin

dlm: cleanup plock_op vs plock_xop

2023-08-11T09:53:45+00:00

[ Upstream commit bcbb4ba6c9ba81e6975b642a2cade68044cd8a66 ]

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 
Signed-off-by: David Teigland 
Stable-dep-of: 59e45c758ca1 ("fs: dlm: interrupt posix locks only when process is killed")
Signed-off-by: Sasha Levin