Instead of creating our own kthread (dlm_astd) to deliver
callbacks for all lockspaces, use a per-lockspace workqueue
to deliver the callbacks. This eliminates complications and
slowdowns from many lockspaces sharing the same thread.
Signed-off-by: David Teigland <teigland@redhat.com>
By pre-allocating rsb structs before searching the hash
table, they can be inserted immediately. This avoids
always having to repeat the search when adding the struct
to hash list.
This also adds space to the rsb struct for a max resource
name, so an rsb allocation can be used by any request.
The constant size also allows us to finally use a slab
for the rsb structs.
Signed-off-by: David Teigland <teigland@redhat.com>
This is simpler and quicker than the hash table, and
avoids needing to search the hash list for every new
lkid to check if it's used.
Signed-off-by: David Teigland <teigland@redhat.com>
Allocate dlm hash tables in the vmalloc area to allow a greater
maximum size without restructuring of the hash table code.
Signed-off-by: Bryn M. Reeves <bmr@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
Add an option (disabled by default) to print a warning message
when a lock has been waiting a configurable amount of time for
a reply message from another node. This is mainly for debugging.
Signed-off-by: David Teigland <teigland@redhat.com>
Constify struct sysfs_ops.
This is part of the ops structure constification
effort started by Arjan van de Ven et al.
Benefits of this constification:
* prevents modification of data that is shared
(referenced) by many other structure instances
at runtime
* detects/prevents accidental (but not intentional)
modification attempts on archs that enforce
read-only kernel data at runtime
* potentially better optimized code as the compiler
can assume that the const data cannot be changed
* the compiler/linker move const data into .rodata
and therefore exclude them from false sharing
Signed-off-by: Emese Revfy <re.emese@gmail.com>
Acked-by: David Teigland <teigland@redhat.com>
Acked-by: Matt Domsch <Matt_Domsch@dell.com>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Acked-by: Hans J. Koch <hjk@linutronix.de>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Although it is possible to get this information from the path,
its much easier to provide the lockspace as a seperate env
variable.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
Replace all GFP_KERNEL and ls_allocation with GFP_NOFS.
ls_allocation would be GFP_KERNEL for userland lockspaces
and GFP_NOFS for file system lockspaces.
It was discovered that any lockspaces on the system can
affect all others by triggering memory reclaim in the
file system which could in turn call back into the dlm
to acquire locks, deadlocking dlm threads that were
shared by all lockspaces, like dlm_recv.
Signed-off-by: David Teigland <teigland@redhat.com>
When a lockspace was joined multiple times, the global dlm
use count was incremented when it should not have been. This
caused the global dlm threads to not be stopped when all
lockspaces were eventually be removed.
Signed-off-by: David Teigland <teigland@redhat.com>
The ls_dirtbl[].lock was an rwlock, but since it was only used in write
mode a spinlock will suffice.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
The rwlock is almost always used in write mode, so there's no reason
to not use a spinlock instead.
Signed-off-by: David Teigland <teigland@redhat.com>
Fixes a regression from commit 0f8e0d9a31,
"dlm: allow multiple lockspace creates".
An extraneous 'else' slipped into a code fragment being moved from
release_lockspace() to dlm_release_lockspace(). The result of the
unwanted 'else' is that dlm threads and structures are not stopped
and cleaned up when the final dlm lockspace is removed. Trying to
create a new lockspace again afterward will fail with
"kmem_cache_create: duplicate cache dlm_conn" because the cache
was not previously destroyed.
Signed-off-by: David Teigland <teigland@redhat.com>
If dlm_controld (the userspace daemon that controls the setup and
recovery of the dlm) fails, the kernel should shut down the lockspaces
in the kernel rather than leaving them running. This is detected by
having dlm_controld hold a misc device open while running, and if
the kernel detects a close while the daemon is still needed, it stops
the lockspaces in the kernel.
Knowing that the userspace daemon isn't running also allows the
lockspace create/remove routines to avoid waiting on the daemon
for join/leave operations.
Signed-off-by: David Teigland <teigland@redhat.com>
Add a count for lockspace create and release so that create can
be called multiple times to use the lockspace from different places.
Also add the new flag DLM_LSFL_NEWEXCL to create a lockspace with
the previous behavior of returning -EEXIST if the lockspace already
exists.
Signed-off-by: David Teigland <teigland@redhat.com>
__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
it moves 365 bytes from .text to .init.text, and 30 bytes from .text to
.exit.text, saves memory.
Signed-off-by: Denis Cheng <crquan@gmail.com>
Signed-off-by: David Teigland <teigland@redhat.com>
The dlm functions in memory.c should use the dlm_ prefix. Also, use
kzalloc/kfree directly for dlm_direntry's, removing the wrapper functions.
Signed-off-by: David Teigland <teigland@redhat.com>
This patch adds a proper prototype for some functions in
fs/dlm/dlm_internal.h
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: David Teigland <teigland@redhat.com>
There is no need for kobject_unregister() anymore, thanks to Kay's
kobject cleanup changes, so replace all instances of it with
kobject_put().
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Stop using kobject_register, as this way we can control the sending of
the uevent properly, after everything is properly initialized.
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
kernel_kset does not need to be a kset, but a much simpler kobject now
that we have kobj_attributes.
We also rename kernel_kset to kernel_kobj to catch all users of this
symbol with a build error instead of an easy-to-ignore build warning.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Dynamically create the kset instead of declaring it statically. We also
rename kernel_subsys to kernel_kset to catch all users of this symbol
with a build error instead of an easy-to-ignore build warning.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Dynamically create the kset instead of declaring it statically.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
We don't need a "default" ktype for a kset. We should set this
explicitly every time for each kset. This change is needed so that we
can make ksets dynamic, and cleans up one of the odd, undocumented
assumption that the kset/kobject/ktype model has.
This patch is based on a lot of help from Kay Sievers.
Nasty bug in the block code was found by Dave Young
<hidave.darkstar@gmail.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* master.kernel.org:/pub/scm/linux/kernel/git/gregkh/driver-2.6: (75 commits)
PM: merge device power-management source files
sysfs: add copyrights
kobject: update the copyrights
kset: add some kerneldoc to help describe what these strange things are
Driver core: rename ktype_edd and ktype_efivar
Driver core: rename ktype_driver
Driver core: rename ktype_device
Driver core: rename ktype_class
driver core: remove subsystem_init()
sysfs: move sysfs file poll implementation to sysfs_open_dirent
sysfs: implement sysfs_open_dirent
sysfs: move sysfs_dirent->s_children into sysfs_dirent->s_dir
sysfs: make sysfs_root a regular directory dirent
sysfs: open code sysfs_attach_dentry()
sysfs: make s_elem an anonymous union
sysfs: make bin attr open get active reference of parent too
sysfs: kill unnecessary NULL pointer check in sysfs_release()
sysfs: kill unnecessary sysfs_get() in open paths
sysfs: reposition sysfs_dirent->s_mode.
sysfs: kill sysfs_update_file()
...
A kset should not have its name set directly, so dynamically set the
name at runtime.
This is needed to remove the static array in the kobject structure which
will be changed in a future patch.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Introduce a per-lockspace rwsem that's held in read mode by dlm_recv
threads while working in the dlm. This allows dlm_recv activity to be
suspended when the lockspace transitions to, from and between recovery
cycles.
The specific bug prompting this change is one where an in-progress
recovery cycle is aborted by a new recovery cycle. While dlm_recv was
processing a recovery message, the recovery cycle was aborted and
dlm_recoverd began cleaning up. dlm_recv decremented recover_locks_count
on an rsb after dlm_recoverd had reset it to zero. This is fixed by
suspending dlm_recv (taking write lock on the rwsem) before aborting the
current recovery.
The transitions to/from normal and recovery modes are simplified by using
this new ability to block dlm_recv. The switch from normal to recovery
mode means dlm_recv goes from processing locking messages, to saving them
for later, and vice versa. Races are avoided by blocking dlm_recv when
setting the flag that switches between modes.
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Mask off the recently added DLM_LSFL_FS flag when setting the exflags.
This way all the nodes in the lockspace aren't required to have the FS
flag set, since we later check that exflags matches among all nodes.
Signed-off-by: Patrick Caulfield <pcaulfie@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Add a new flag, DLM_LSFL_FS, to be used when a file system creates a lockspace.
This flag causes the dlm to use GFP_NOFS for allocations instead of GFP_KERNEL.
(This updated version of the patch uses gfp_t for ls_allocation.)
Signed-Off-By: Patrick Caulfield <pcaulfie@redhat.com>
Signed-Off-By: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Joining the lockspace should wait for the initial round of inter-node
config checks to complete before returning. This way, if there's a
configuration mismatch between the joining node and the existing nodes,
the join can fail and return an error to the application.
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Fix the error path when exiting new_lockspace(). It was kfree'ing the
lockspace struct at the end, but that's only valid if it exits before
kobject_register occured. After kobject_register we have to let the
kobject do the freeing.
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
New features: lock timeouts and time warnings. If the DLM_LKF_TIMEOUT
flag is set, then the request/conversion will be canceled after waiting
the specified number of centiseconds (specified per lock). This feature
is only available for locks requested through libdlm (can be enabled for
kernel dlm users if there's a use for it.)
If the new DLM_LSFL_TIMEWARN flag is set when creating the lockspace, then
a warning message will be sent to userspace (using genetlink) after a
request/conversion has been waiting for a given number of centiseconds
(configurable per node). The time warnings will be used in the future
to do deadlock detection in userspace.
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Don't let dlm_scand run during recovery since it may try to do a resource
directory removal while the directory nodes are changing.
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
We need to work on cleaning up the relationship between kobjects, ksets and
ktypes. The removal of 'struct subsystem' is the first step of this,
especially as it is not really needed at all.
Thanks to Kay for fixing the bugs in this patch.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Full cancel and force-unlock support. In the past, cancel and force-unlock
wouldn't work if there was another operation in progress on the lock. Now,
both cancel and unlock-force can overlap an operation on a lock, meaning there
may be 2 or 3 operations in progress on a lock in parallel. This support is
important not only because cancel and force-unlock are explicit operations
that an app can use, but both are used implicitly when a process exits while
holding locks.
Summary of changes:
- add-to and remove-from waiters functions were rewritten to handle situations
with more than one remote operation outstanding on a lock
- validate_unlock_args detects when an overlapping cancel/unlock-force
can be sent and when it needs to be delayed until a request/lookup
reply is received
- processing request/lookup replies detects when cancel/unlock-force
occured during the op, and carries out the delayed cancel/unlock-force
- manipulation of the "waiters" (remote operation) state of a lock moved under
the standard rsb mutex that protects all the other lock state
- the two recovery routines related to locks on the waiters list changed
according to the way lkb's are now locked before accessing waiters state
- waiters recovery detects when lkb's being recovered have overlapping
cancel/unlock-force, and may not recover such locks
- revert_lock (cancel) returns a value to distinguish cases where it did
nothing vs cases where it actually did a cancel; the cancel completion ast
should only be done when cancel did something
- orphaned locks put on new list so they can be found later for purging
- cancel must be called on a lock when making it an orphan
- flag user locks (ENDOFLIFE) at the end of their useful life (to the
application) so we can return an error for any further cancel/unlock-force
- we weren't setting COMP/BAST ast flags if one was already set, so we'd lose
either a completion or blocking ast
- clear an unread bast on a lock that's become unlocked
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Add a "ci_" prefix to the fields in the dlm_config_info struct so that we
can use macros to add configfs functions to access them (in a later
patch). No functional changes in this patch, just naming changes.
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
We often abort a recovery after sending a status request to a remote node.
We want to ignore any potential status reply we get from the remote node.
If we get one of these unwanted replies, we've often moved on to the next
recovery message and incremented the message sequence counter, so the
reply will be ignored due to the seq number. In some cases, we've not
moved on to the next message so the seq number of the reply we want to
ignore is still correct, causing the reply to be accepted. The next
recovery message will then mistake this old reply as a new one.
To fix this, we add the flag RCOM_WAIT to indicate when we can accept a
new reply. We clear this flag if we abort recovery while waiting for a
reply. Before the flag is set again (to allow new replies) we know that
any old replies will be rejected due to their sequence number. We also
initialize the recovery-message sequence number to a random value when a
lockspace is first created. This makes it clear when messages are being
rejected from an old instance of a lockspace that has since been
recreated.
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Requests that arrive after recovery has started are saved in the
requestqueue and processed after recovery is done. Some of these requests
are purged during recovery if they are from nodes that have been removed.
We move the purging of the requests (dlm_purge_requestqueue) to later in
the recovery sequence which allows the routine saving requests
(dlm_add_requestqueue) to avoid filtering out requests by nodeid since the
same will be done by the purge. The current code has add_requestqueue
filtering by nodeid but doesn't hold any locks when accessing the list of
current nodes. This also means that we need to call the purge routine
when the lockspace is being shut down since the add routine will not be
rejecting requests itself any more.
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Now that the lockspace struct is freed when the last sysfs object is released
this patch prevents use of that lockspace by sysfs. We attempt to re-get the
lockspace from the lockspace list and fail the request if it has been removed.
Signed-Off-By: Patrick Caulfield <pcaulfie@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This patch fixes the recounting on the lockspace kobject. Previously the lockspace was freed while userspace could have had a
reference to one of its sysfs files, causing an oops in kref_put.
Now the lockspace kfree is moved into the kobject release() function
Signed-Off-By: Patrick Caulfield <pcaulfie@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Use snprintf(buf, PAGE_SIZE, ...) instead of sprintf in sysfs show
methods.
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
When a new lockspace was being created, the recoverd thread was being
started for it before the lockspace was added to the global list of
lockspaces. The new thread was looking up the lockspace in the global
list and sometimes not finding it due to the race with the original thread
adding it to the list. We need to add the lockspace to the global list
before starting the thread instead of after, and if the new thread can't
find the lockspace for some reason, it should return an error.
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
To aid debugging, it's useful to be able to see what nodeid the dlm is
waiting on for a message reply.
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Display more information from debugfs, particularly locks waiting for
a master lookup or operations waiting for a remote reply.
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This changes the way the dlm handles user locks. The core dlm is now
aware of user locks so they can be dealt with more efficiently. There is
no more dlm_device module which previously managed its own duplicate copy
of every user lock.
Signed-off-by: Patrick Caulfield <pcaulfie@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Expose the current recovery state in sysfs to help in debugging.
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
David Teigland
Bryn M. Reeves
Emese Revfy
Steven Whitehouse
Geert Uytterhoeven
Harvey Harrison
Denis Cheng
Adrian Bunk
Greg Kroah-Hartman
Linus Torvalds
Patrick Caulfield