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2007-07-09[DLM] dump more lock valuesDavid Teigland
Add two more output fields (lkb_flags and rsb nodeid) to the new debugfs file that dumps one lock per line. Also, dump all locks instead of just mastered locks. Accordingly, use a suffix of _locks instead of _master. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-07-09[GFS2] git-gfs2-nmw-build-fixakpm@linux-foundation.org
Cc: Steven Whitehouse <swhiteho@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-07-09[DLM] Telnet to port 21064 can stop all lockspacesPatrick Caulfield
This patch fixes Red Hat bz#245892 Opening a tcp connection from a cluster member to another cluster member targeting the dlm port it is enough to stop every dlm operation in the cluster. This means that GFS and rgmanager will hang. Signed-Off-By: Patrick Caulfield <pcaulfie@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-07-09[DLM] don't require FS flag on all nodesDavid Teigland
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>
2007-07-09[DLM] variable allocationPatrick Caulfield
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>
2007-07-09[DLM] fix reference countingJosef Bacik
This is a fix for the patch 021d2ff3a08019260a1dc002793c92d6bf18afb6 I left off a dlm_hold_rsb which causes the box to panic if you try to use debugfs. This patch fixes the problem. Sorry about that, Signed-off-by: Josef Bacik <jwhiter@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-07-09[DLM] fix socket shutdownPatrick Caulfield
This patch clears the user_data of active sockets as part of cleanup. This prevents any late-arriving data from trying to add jobs to the work queue while we are tidying up. Signed-Off-By: Patrick Caulfield <pcaulfie@redhat.com> Signed-Off-By: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-07-09[DLM] show default protocolDavid Teigland
Display the initial value of the "protocol" config value in configfs. The default value has always been 0 in the past anyway, so it's always appeared to be correct. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-07-09[DLM] dumping master locksDavid Teigland
Add a new debugfs file that dumps a compact list of mastered locks. This will be used by a userland daemon to collect state for deadlock detection. Also, for the existing function that prints all lock state, lock the rsb before going through the lock lists since they can be changing in the course of normal dlm activity. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-07-09[DLM] canceling deadlocked lockDavid Teigland
Add a function that can be used through libdlm by a system daemon to cancel another process's deadlocked lock. A completion ast with EDEADLK is returned to the process waiting for the lock. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-07-09[DLM] timeout fixesDavid Teigland
Various fixes related to the new timeout feature: - add_timeout() missed setting TIMEWARN flag on lkb's when the TIMEOUT flag was already set - clear_proc_locks should remove a dead process's locks from the timeout list - the end-of-life calculation for user locks needs to consider that ETIMEDOUT is equivalent to -DLM_ECANCEL - make initial default timewarn_cs config value visible in configfs - change bit position of TIMEOUT_CANCEL flag so it's not copied to a remote master node - set timestamp on remote lkb's so a lock dump will display the time they've been waiting Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-07-09[DLM] Compile fixSteven Whitehouse
A one liner fix which got missed from the earlier patches. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Cc: Fabio Massimo Di Nitto <fabbione@ubuntu.com> Cc: David Teigland <teigland@redhat.com>
2007-07-09[DLM] fix compile breakageDavid Teigland
In the rush to get the previous patch set sent, a compilation bug I fixed shortly before sending somehow got clobbered, probably by a missed quilt refresh or something. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-07-09[DLM] wait for config check during join [6/6]David Teigland
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>
2007-07-09[DLM] fix new_lockspace error exit [5/6]David Teigland
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>
2007-07-09[DLM] cancel in conversion deadlock [4/6]David Teigland
When conversion deadlock is detected, cancel the conversion and return EDEADLK to the application. This is a new default behavior where before the dlm would allow the deadlock to exist indefinately. The DLM_LKF_NODLCKWT flag can now be used in a conversion to prevent the dlm from performing conversion deadlock detection/cancelation on it. The DLM_LKF_CONVDEADLK flag can continue to be used as before to tell the dlm to demote the granted mode of the lock being converted if it gets into a conversion deadlock. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-07-09[DLM] dlm_device interface changes [3/6]David Teigland
Change the user/kernel device interface used by libdlm: - Add ability for userspace to check the version of the interface. libdlm can now adapt to different versions of the kernel interface. - Increase the size of the flags passed in a lock request so all possible flags can be used from userspace. - Add an opaque "xid" value for each lock. This "transaction id" will be used later to associate locks with each other during deadlock detection. - Add a "timeout" value for each lock. This is used along with the DLM_LKF_TIMEOUT flag. Also, remove a fragment of unused code in device_read(). This patch requires updating libdlm which is backward compatible with older kernels. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-07-09[DLM] add lock timeouts and warnings [2/6]David Teigland
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>
2007-07-09[DLM] block scand during recovery [1/6]David Teigland
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>
2007-07-09[DLM] keep dlm from panicing when traversing rsb list in debugfsJosef Bacik
This problem was originally reported against GFS6.1, but the same issue exists in upstream DLM. This patch keeps the rsb iterator assigning under the rsbtbl list lock. Each time we process an rsb we grab a reference to it to make sure it is not freed out from underneath us, and then put it when we get the next rsb in the list or move onto another list. Signed-off-by: Josef Bacik <jwhiter@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-07-09[DLM] fix a couple of racesSatyam Sharma
Fix two races in fs/dlm/config.c: (1) Grab the configfs subsystem semaphore before calling config_group_find_obj() in get_space(). This solves a potential race between get_space() and concurrent mkdir(2) or rmdir(2). (2) Grab a reference on the found config_item _while_ holding the configfs subsystem semaphore in get_comm(), and not after it. This solves a potential race between get_comm() and concurrent rmdir(2). Signed-off-by: Satyam Sharma <ssatyam@cse.iitk.ac.in> Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-07-07DLM must depend on SYSFSAdrian Bunk
The dependency of DLM on SYSFS got lost in commit 6ed7257b46709e87d79ac2b6b819b7e0c9184998 resulting in the following compile error with CONFIG_DLM=y, CONFIG_SYSFS=n: <-- snip --> ... LD .tmp_vmlinux1 fs/built-in.o: In function `dlm_lockspace_init': /home/bunk/linux/kernel-2.6/linux-2.6.22-rc6-mm1/fs/dlm/lockspace.c:231: undefined reference to `kernel_subsys' fs/built-in.o: In function `configfs_init': /home/bunk/linux/kernel-2.6/linux-2.6.22-rc6-mm1/fs/configfs/mount.c:143: undefined reference to `kernel_subsys' make[1]: *** [.tmp_vmlinux1] Error 1 <-- snip --> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6-nmwLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6-nmw: (34 commits) [GFS2] Uncomment sprintf_symbol calling code [DLM] lowcomms style [GFS2] printk warning fixes [GFS2] Patch to fix mmap of stuffed files [GFS2] use lib/parser for parsing mount options [DLM] Lowcomms nodeid range & initialisation fixes [DLM] Fix dlm_lowcoms_stop hang [DLM] fix mode munging [GFS2] lockdump improvements [GFS2] Patch to detect corrupt number of dir entries in leaf and/or inode blocks [GFS2] bz 236008: Kernel gpf doing cat /debugfs/gfs2/xxx (lock dump) [DLM] fs/dlm/ast.c should #include "ast.h" [DLM] Consolidate transport protocols [DLM] Remove redundant assignment [GFS2] Fix bz 234168 (ignoring rgrp flags) [DLM] change lkid format [DLM] interface for purge (2/2) [DLM] add orphan purging code (1/2) [DLM] split create_message function [GFS2] Set drop_count to 0 (off) by default ...
2007-05-02remove "struct subsystem" as it is no longer neededGreg Kroah-Hartman
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>
2007-05-01[DLM] lowcomms styleDavid Teigland
Replace some printk with log_print, and fix some simple cases of lines over 80. Also, return -ENOTCONN if lowcomms_start fails due to no local IP address being available. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-05-01[DLM] Lowcomms nodeid range & initialisation fixesPatrick Caulfield
Fix a few range & initialization bugs in lowcomms. - max_nodeid is really the highest nodeid encountered, so all loops must include it in their iterations. - clean dlm_local_count & connection_idr so we can do a clean restart. - Remove a spurious BUG_ON Signed-Off-By: Patrick Caulfield <pcaulfie@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-05-01[DLM] Fix dlm_lowcoms_stop hangJosef Bacik
When you attempt to release a lockspace in DLM, it will hang trying to down a semaphore that has already been downed. The attached patch fixes the problem. Signed-off-by: Josef Bacik <jwhiter@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Cc: Patrick Caulfield <pcaulfie@redhat.com>
2007-05-01[DLM] fix mode mungingDavid Teigland
There are flags to enable two specialized features in the dlm: 1. CONVDEADLK causes the dlm to resolve conversion deadlocks internally by changing the granted mode of locks to NL. 2. ALTPR/ALTCW cause the dlm to change the requested mode of locks to PR or CW to grant them if the normal requested mode can't be granted. GFS direct i/o exercises both of these features, especially when mixed with buffered i/o. The dlm has problems with them. The first problem is on the master node. If it demotes a lock as a part of converting it, the actual step of converting the lock isn't being done after the demotion, the lock is just left sitting on the granted queue with a granted mode of NL. I think the mistaken assumption was that the call to grant_pending_locks() would grant it, but that function naturally doesn't look at locks on the granted queue. The second problem is on the process node. If the master either demotes or gives an altmode, the munging of the gr/rq modes is never done in the process copy of the lock, leaving the master/process copies out of sync. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-05-01[DLM] fs/dlm/ast.c should #include "ast.h"Adrian Bunk
Every file should include the headers containing the prototypes for it's global functions. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-05-01[DLM] Consolidate transport protocolsPatrick Caulfield
This patch consolidates the TCP & SCTP protocols for the DLM into a single file and makes it switchable at run-time (well, at least before the DLM actually starts up!) For RHEL5 this patch requires Neil Horman's patch that expands the in-kernel socket API but that has already been twice ACKed so it should be OK. The patch adds a new lowcomms.c file that replaces the existing lowcomms-sctp.c & lowcomms-tcp.c files. Signed-off-By: Patrick Caulfield <pcaulfie@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-05-01[DLM] Remove redundant assignmentPatrick Caulfield
This patch removes a redundant (and incorrect) assignment from compat_output Signed-Off-By: Patrick Caulfield <pcaulfie@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-05-01[DLM] change lkid formatDavid Teigland
A lock id is a uint32 and is used as an opaque reference to the lock. For userland apps, the lkid is passed up, through libdlm, as the return value from a write() on the dlm device. This created a problem when the high bit was 1, making the lkid look like an error. This is fixed by changing how the lkid is composed. The low 16 bits identified the hash bucket for the lock and the high 16 bits were a per-bucket counter (which eventually hit 0x8000 causing the problem). These are simply swapped around; the number of hash table buckets is far below 0x8000, making all lkid's positive when viewed as signed. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-05-01[DLM] interface for purge (2/2)David Teigland
Add code to accept purge commands from userland. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-05-01[DLM] add orphan purging code (1/2)David Teigland
Add code for purging orphan locks. A process can also purge all of its own non-orphan locks by passing a pid of zero. Code already exists for processes to create persistent locks that become orphans when the process exits, but the complimentary capability for another process to then purge these orphans has been missing. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-05-01[DLM] split create_message functionDavid Teigland
This splits the current create_message() function into two parts so that later patches can call the new lower-level _create_message() function when they don't have an rsb struct. No functional change in this patch. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-05-01[DLM] overlapping cancel and unlockDavid Teigland
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>
2007-05-01[DLM] fix coverity-spotted stupidityPatrick Caulfield
Replacement patch to remove redundant code rather than moving it around. Signed-Off-By: Patrick Caulfield <pcaulfie@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-05-01[DLM] Don't delete misc device if lockspace removal failsPatrick Caulfield
Currently if the lockspace removal fails the misc device associated with a lockspace is left deleted. After that there is no way to access the orphaned lockspace from userland. This patch recreates the misc device if th dlm_release_lockspace fails. I believe this is better than attempting to remove the lockspace first because that leaves an unattached device lying around. The potential gap in which there is no access to the lockspace between removing the misc device and recreating it is acceptable ... after all the application is trying to remove it, and only new users of the lockspace will be affected. Signed-Off-By: Patrick Caulfield <pcaulfie@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-05-01[DLM] Fix uninitialised variable in receivingPatrick Caulfield
The length of the second element of the kvec array was not initialised before being added to the first one. This could cause invalid lengths to be passed to kernel_recvmsg Signed-Off-By: Patrick Caulfield <pcaulfie@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-03-07[DLM] fs/dlm/user.c should #include "user.h"Adrian Bunk
Every file should include the headers containing the prototypes for it's global functions. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-02-12[PATCH] mark struct file_operations const 6Arjan van de Ven
Many struct file_operations in the kernel can be "const". Marking them const moves these to the .rodata section, which avoids false sharing with potential dirty data. In addition it'll catch accidental writes at compile time to these shared resources. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-11[PATCH] Transform kmem_cache_alloc()+memset(0) -> kmem_cache_zalloc().Robert P. J. Day
Replace appropriate pairs of "kmem_cache_alloc()" + "memset(0)" with the corresponding "kmem_cache_zalloc()" call. Signed-off-by: Robert P. J. Day <rpjday@mindspring.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Andi Kleen <ak@muc.de> Cc: Roland McGrath <roland@redhat.com> Cc: James Bottomley <James.Bottomley@steeleye.com> Cc: Greg KH <greg@kroah.com> Acked-by: Joel Becker <Joel.Becker@oracle.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Jan Kara <jack@ucw.cz> Cc: Michael Halcrow <mhalcrow@us.ibm.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: James Morris <jmorris@namei.org> Cc: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-09[PATCH] dlm: use kern_recvmsg()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-05[DLM] fix softlockup in dlm_recvPatrick Caulfield
This patch stops the dlm_recv workqueue from busy-waiting when a node disconnects. This can cause soft lockup errors on debug systems and bad performance generally. Signed-Off-By: Patrick Caulfield <pcaulfie@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-02-05[DLM] zero new user lvbsDavid Teigland
A new lvb for a userland lock wasn't being initialized to zero. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-02-05[DLM/GFS2] indent help textRandy Dunlap
Indent help text as expected. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-02-05[GFS2/DLM] fix GFS2 circular dependencyAdrian Bunk
On Sun, Jan 28, 2007 at 11:08:18AM +0100, Jiri Slaby wrote: > Andrew Morton napsal(a): > >Temporarily at > > > > http://userweb.kernel.org/~akpm/2.6.20-rc6-mm1/ > > Unable to select IPV6. Menuconfig doesn't offer it when INET is selected. > When it's not it appears in the menu, but after state change it gets away. > The same behaviour in xconfig, gconfig. > > $ mkdir ../a/tst > $ make O=../a/tst menuconfig > HOSTCC scripts/basic/fixdep > [...] > HOSTLD scripts/kconfig/mconf > scripts/kconfig/mconf arch/i386/Kconfig > Warning! Found recursive dependency: INET GFS2_FS_LOCKING_DLM SYSFS > OCFS2_FS INET > > Maybe this is the problem? Yes, patch below. > regards, cu Adrian <-- snip --> This patch fixes a circular dependency by letting GFS2_FS_LOCKING_DLM and DLM depend on instead of select SYSFS. Since SYSFS depends on EMBEDDED this change shouldn't cause any problems for users. Signed-off-by: Adrian Bunk <bunk@stusta.de> Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-02-05[GFS2/DLM] use sysfsRandy Dunlap
With CONFIG_DLM=m, CONFIG_PROC_FS=n, and CONFIG_SYSFS=n, kernel build fails with: WARNING: "kernel_subsys" [fs/gfs2/locking/dlm/lock_dlm.ko] undefined! WARNING: "kernel_subsys" [fs/dlm/dlm.ko] undefined! WARNING: "kernel_subsys" [fs/configfs/configfs.ko] undefined! make[1]: *** [__modpost] Error 1 make: *** [modules] Error 2 Since fs/dlm/lockspace.c and fs/gfs2/locking/dlm/sysfs.c use kernel_subsys, they should either DEPEND on it or SELECT it. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-02-05[DLM] can miss clearing resend flagDavid Teigland
A long, complicated sequence of events, beginning with the RESEND flag not being cleared on an lkb, can result in an unlock never completing. - lkb on waiters list for remote lookup - the remote node is both the dir node and the master node, so it optimizes the lookup into a request and sends a request reply back - the request reply is saved on the requestqueue to be processed after recovery - recovery runs dlm_recover_waiters_pre() which sets RESEND flag so the lookup will be resent after recovery - end of recovery: process_requestqueue takes saved request reply which removes the lkb off the waitesr list, _without_ clearing the RESEND flag - end of recovery: dlm_recover_waiters_post() doesn't do anything with the now completed lookup lkb (would usually clear RESEND) - later, the node unmounts, unlocks this lkb that still has RESEND flag set - the lkb is on the waiters list again, now for unlock, when recovery occurs, dlm_recover_waiters_pre() shows the lkb for unlock with RESEND set, doesn't do anything since the master still exists - end of recovery: dlm_recover_waiters_post() takes this lkb off the waiters list because it has the RESEND flag set, then reports an error because unlocks are never supposed to be handled in recover_waiters_post(). - later, the unlock reply is received, doesn't find the lkb on the waiters list because recover_waiters_post() has wrongly removed it. - the unlock operation has been lost, and we're left with a stray granted lock - unmount spins waiting for the unlock to complete The visible evidence of this problem will be a node where gfs umount is spinning, the dlm waiters list will be empty, and the dlm locks list will show a granted lock. The fix is simply to clear the RESEND flag when taking an lkb off the waiters list. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-02-05[DLM] saved dlm message can be droppedDavid Teigland
dlm_receive_message() returns 0 instead of returning 'error'. What would happen is that process_requestqueue would take a saved message off the requestqueue and call receive_message on it. receive_message would then see that recovery had been aborted, set error to EINTR, and 'goto out', expecting that the error would be returned. Instead, 0 was always returned, so process_requestqueue would think that the message had been processed and delete it instead of saving it to process next time. This means the message (usually an unlock in my tests) would be lost. Signed-off-by: David Teigland <teigland@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>