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author | Mark Fasheh <mfasheh@suse.com> | 2008-07-21 14:29:16 -0700 |
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committer | Mark Fasheh <mfasheh@suse.com> | 2008-10-13 13:57:57 -0700 |
commit | 53da4939f349d4edd283b043219221ca5b78e4d4 (patch) | |
tree | 3e0f8e1bd5474822431cffd1e449df9b639e1772 /fs/ocfs2/stack_user.c | |
parent | a447c0932445f92ce6f4c1bd020f62c5097a7842 (diff) | |
download | lwn-53da4939f349d4edd283b043219221ca5b78e4d4.tar.gz lwn-53da4939f349d4edd283b043219221ca5b78e4d4.zip |
ocfs2: POSIX file locks support
This is actually pretty easy since fs/dlm already handles the bulk of the
work. The Ocfs2 userspace cluster stack module already uses fs/dlm as the
underlying lock manager, so I only had to add the right calls.
Cluster-aware POSIX locks ("plocks") can be turned off by the same means at
UNIX locks - mount with 'noflocks', or create a local-only Ocfs2 volume.
Internally, the file system uses two sets of file_operations, depending on
whether cluster aware plocks is required. This turns out to be easier than
implementing local-only versions of ->lock.
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Diffstat (limited to 'fs/ocfs2/stack_user.c')
-rw-r--r-- | fs/ocfs2/stack_user.c | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/fs/ocfs2/stack_user.c b/fs/ocfs2/stack_user.c index 353fc35c6748..faec2d879357 100644 --- a/fs/ocfs2/stack_user.c +++ b/fs/ocfs2/stack_user.c @@ -28,6 +28,7 @@ #include "ocfs2.h" /* For struct ocfs2_lock_res */ #include "stackglue.h" +#include <linux/dlm_plock.h> /* * The control protocol starts with a handshake. Until the handshake @@ -746,6 +747,37 @@ static void user_dlm_dump_lksb(union ocfs2_dlm_lksb *lksb) { } +static int user_plock(struct ocfs2_cluster_connection *conn, + u64 ino, + struct file *file, + int cmd, + struct file_lock *fl) +{ + /* + * This more or less just demuxes the plock request into any + * one of three dlm calls. + * + * Internally, fs/dlm will pass these to a misc device, which + * a userspace daemon will read and write to. + * + * For now, cancel requests (which happen internally only), + * are turned into unlocks. Most of this function taken from + * gfs2_lock. + */ + + if (cmd == F_CANCELLK) { + cmd = F_SETLK; + fl->fl_type = F_UNLCK; + } + + if (IS_GETLK(cmd)) + return dlm_posix_get(conn->cc_lockspace, ino, file, fl); + else if (fl->fl_type == F_UNLCK) + return dlm_posix_unlock(conn->cc_lockspace, ino, file, fl); + else + return dlm_posix_lock(conn->cc_lockspace, ino, file, cmd, fl); +} + /* * Compare a requested locking protocol version against the current one. * @@ -839,6 +871,7 @@ static struct ocfs2_stack_operations ocfs2_user_plugin_ops = { .dlm_unlock = user_dlm_unlock, .lock_status = user_dlm_lock_status, .lock_lvb = user_dlm_lvb, + .plock = user_plock, .dump_lksb = user_dlm_dump_lksb, }; |