This patch introduces a new flag DLM_PLOCK_FL_NO_REPLY in case an dlm plock operation should not 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. In case of an error in dlm user space software e.g. dlm_controld we get an reply with an error back. This cannot be matched because there is no op to match in recv_list. We filter now on DLM_PLOCK_FL_NO_REPLY in case we had an error back as reply. In newer dlm_controld version it will never send a result back when DLM_PLOCK_FL_NO_REPLY is set. This filter is a workaround to handle older dlm_controld versions.
Fixes: 901025d2f319 ("dlm: make plock operation killable") Cc: stable@vger.kernel.org Signed-off-by: Alexander Aring aahringo@redhat.com --- fs/dlm/plock.c | 23 +++++++++++++++++++---- include/uapi/linux/dlm_plock.h | 1 + 2 files changed, 20 insertions(+), 4 deletions(-)
diff --git a/fs/dlm/plock.c b/fs/dlm/plock.c index 70a4752ed913..7fe9f4b922d3 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))) @@ -433,6 +433,21 @@ static ssize_t dev_write(struct file *file, const char __user *u, size_t count, if (check_version(&info)) return -EINVAL;
+ /* Some old dlm user space software will send replies back, + * even if DLM_PLOCK_FL_NO_REPLY is set (because the flag is + * new) e.g. if a error occur. We can't match them in recv_list + * because they were never be part of it. We filter it here, + * new dlm user space software will filter it in user space. + * + * In future this handling can be removed. + */ + if (info.flags & DLM_PLOCK_FL_NO_REPLY) { + pr_info("Received unexpected reply from op %d, " + "please update DLM user space software!\n", + info.optype); + return count; + } + /* * The results for waiting ops (SETLKW) can be returned in any * order, so match all fields to find the op. The results for 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];