This patch introduces a new flag DLM_PLOCK_FL_NO_REPLY in case an dlm plock operation should never send a reply back. Currently this is kind of being handled in DLM_PLOCK_FL_CLOSE, but DLM_PLOCK_FL_CLOSE has more meanings that it will remove all waiters for a specific nodeid/owner values in by doing a unlock operation. That DLM_PLOCK_FL_CLOSE never sends a reply back is not true in case of some user applications and an error occurred. The new DLM_PLOCK_FL_NO_REPLY flag will tell the user space application to never ever send a reply back. As this is now combined with DLM_PLOCK_FL_CLOSE we can use DLM_PLOCK_FL_NO_REPLY to check if older user space application still doing it and drop the message.
Expecting the user space applications is just copying flags from the request to the reply, we can use now DLM_PLOCK_FL_NO_REPLY as workaround to ignore replies from older dlm_controld versions.
Signed-off-by: Alexander Aring aahringo@redhat.com --- fs/dlm/plock.c | 16 ++++++++++------ include/uapi/linux/dlm_plock.h | 1 + 2 files changed, 11 insertions(+), 6 deletions(-)
diff --git a/fs/dlm/plock.c b/fs/dlm/plock.c index 869595a995f7..1fa5b04d0298 100644 --- a/fs/dlm/plock.c +++ b/fs/dlm/plock.c @@ -96,7 +96,7 @@ static void do_unlock_close(const struct dlm_plock_info *info) op->info.end = OFFSET_MAX; op->info.owner = info->owner;
- op->info.flags |= DLM_PLOCK_FL_CLOSE; + op->info.flags |= (DLM_PLOCK_FL_CLOSE | DLM_PLOCK_FL_NO_REPLY); send_op(op); }
@@ -293,7 +293,7 @@ int dlm_posix_unlock(dlm_lockspace_t *lockspace, u64 number, struct file *file, op->info.owner = (__u64)(long) fl->fl_owner;
if (fl->fl_flags & FL_CLOSE) { - op->info.flags |= DLM_PLOCK_FL_CLOSE; + op->info.flags |= (DLM_PLOCK_FL_CLOSE | DLM_PLOCK_FL_NO_REPLY); send_op(op); rv = 0; goto out; @@ -392,7 +392,7 @@ static ssize_t dev_read(struct file *file, char __user *u, size_t count, spin_lock(&ops_lock); if (!list_empty(&send_list)) { op = list_first_entry(&send_list, struct plock_op, list); - if (op->info.flags & DLM_PLOCK_FL_CLOSE) + if (op->info.flags & DLM_PLOCK_FL_NO_REPLY) list_del(&op->list); else list_move_tail(&op->list, &recv_list); @@ -407,7 +407,7 @@ static ssize_t dev_read(struct file *file, char __user *u, size_t count, that were generated by the vfs cleaning up for a close (the process did not make an unlock call). */
- if (op->info.flags & DLM_PLOCK_FL_CLOSE) + if (op->info.flags & DLM_PLOCK_FL_NO_REPLY) dlm_release_plock_op(op);
if (copy_to_user(u, &info, sizeof(info))) @@ -434,11 +434,15 @@ static ssize_t dev_write(struct file *file, const char __user *u, size_t count, return -EINVAL;
/* Some dlm user space software will send replies back, - * even if DLM_PLOCK_FL_CLOSE is set e.g. if an error occur. + * even if DLM_PLOCK_FL_NO_REPLY is set e.g. if an error + * occur as the op is unknown, etc. + * * We can't match them in recv_list because they were never * be part of it. + * + * In the future, this handling could be removed. */ - if (info.flags & DLM_PLOCK_FL_CLOSE) + if (info.flags & DLM_PLOCK_FL_NO_REPLY) return count;
/* diff --git a/include/uapi/linux/dlm_plock.h b/include/uapi/linux/dlm_plock.h index 63b6c1fd9169..8dfa272c929a 100644 --- a/include/uapi/linux/dlm_plock.h +++ b/include/uapi/linux/dlm_plock.h @@ -25,6 +25,7 @@ enum { };
#define DLM_PLOCK_FL_CLOSE 1 +#define DLM_PLOCK_FL_NO_REPLY 2
struct dlm_plock_info { __u32 version[3];