Commit Graph

14 Commits

Author SHA1 Message Date
Joel Becker e6bd07aee7 configfs: Convert subsystem semaphore to mutex
Convert the su_sem member of struct configfs_subsystem to a struct
mutex, as that's what it is. Also convert all the users and update
Documentation/configfs.txt and Documentation/configfs_example.c
accordingly.

[ Conflict in fs/dlm/config.c with commit
  3168b0780d manually resolved. --Mark ]

Inspired-by: Satyam Sharma <ssatyam@cse.iitk.ac.in>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2007-07-10 17:10:56 -07:00
Satyam Sharma 3fe6c5ce11 [PATCH] configfs+dlm: Rename config_group_find_obj and state semantics clearly
Configfs being based upon sysfs code, config_group_find_obj() is probably
so named because of the similar kset_find_obj() in sysfs. However,
"kobject"s in sysfs become "config_item"s in configfs, so let's call it
config_group_find_item() instead, for sake of uniformity, and make
corresponding change in the users of this function.

BTW a crucial difference between kset_find_obj and config_group_find_item
is in locking expectations. kset_find_obj does its locking by itself, but
config_group_find_item expects the *caller* to do the locking. The reason
for this: kset's have their own locks, config_group's don't but instead
rely on the subsystem mutex. And, subsystem needn't necessarily be around
when config_group_find_item() is called.

So let's state these locking semantics explicitly, and rectify the comment,
otherwise bugs could continue to occur in future, as they did in the past
(refer commit d82b8191e238 in gfs2-2.6-fixes.git).

[ I also took the opportunity to fix some bad whitespace and
double-empty lines. --Joel ]

[ Conflict in fs/dlm/config.c with commit
  3168b0780d manually resolved. --Mark ]

Signed-off-by: Satyam Sharma <ssatyam@cse.iitk.ac.in>
Cc: David Teigland <teigland@redhat.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2007-07-10 17:02:31 -07:00
Satyam Sharma 9b1d9aa4e9 [PATCH] configfs+dlm: Separate out __CONFIGFS_ATTR into configfs.h
fs/dlm/config.c contains a useful generic macro called __CONFIGFS_ATTR
that is similar to sysfs' __ATTR macro that makes defining attributes
easy for any user of configfs. Separate it out into configfs.h so that
other users (forthcoming in dynamic netconsole patchset) can use it too.

Signed-off-by: Satyam Sharma <ssatyam@cse.iitk.ac.in>
Cc: David Teigland <teigland@redhat.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2007-07-10 16:52:27 -07:00
David Teigland 0b7cac0fb0 [DLM] show default protocol
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 08:22:59 +01:00
David Teigland 84d8cd69a8 [DLM] timeout fixes
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 08:22:52 +01:00
David Teigland 3ae1acf93a [DLM] add lock timeouts and warnings [2/6]
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 08:22:33 +01:00
Satyam Sharma 3168b0780d [DLM] fix a couple of races
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>
2007-07-09 08:22:10 +01:00
Patrick Caulfield 6ed7257b46 [DLM] Consolidate transport protocols
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 09:11:23 +01:00
David Teigland d200778e12 [DLM] expose dlm_config_info fields in configfs
Make the dlm_config_info values readable and writeable via configfs
entries.

Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-02-05 13:36:43 -05:00
David Teigland 99fc64874a [DLM] add config entry to enable log_debug
Add a new dlm_config_info field to enable log_debug output and change
log_debug() to use it.

Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2007-02-05 13:36:40 -05:00
David Teigland 68c817a1c4 [DLM] rename dlm_config_info fields
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>
2007-02-05 13:36:37 -05:00
David Teigland 1c032c0311 [DLM] PATCH 2/3 dlm: lowcomms close
When a node is removed from a lockspace configuration, close our
connection to it, clearing any remaining messages for it.

Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Patrick Caulfield <pcaulfie@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2006-04-28 10:50:41 -04:00
David Teigland 901359256b [DLM] Update DLM to the latest patch level
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steve Whitehouse <swhiteho@redhat.com>
2006-01-20 08:47:07 +00:00
David Teigland e7fd41792f [DLM] The core of the DLM for GFS2/CLVM
This is the core of the distributed lock manager which is required
to use GFS2 as a cluster filesystem. It is also used by CLVM and
can be used as a standalone lock manager independantly of either
of these two projects.

It implements VAX-style locking modes.

Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steve Whitehouse <swhiteho@redhat.com>
2006-01-18 09:30:29 +00:00