[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>

1 files changed, 10 insertions, 0 deletions

diff --git a/fs/dlm/dlm_internal.h b/fs/dlm/dlm_internal.h
index 30994d68f6a0..65a5fc076b8a 100644
--- a/fs/dlm/dlm_internal.h
+++ b/fs/dlm/dlm_internal.h
@@ -213,8 +213,10 @@ struct dlm_args {
 #define DLM_IFL_OVERLAP_UNLOCK  0x00080000
 #define DLM_IFL_OVERLAP_CANCEL  0x00100000
 #define DLM_IFL_ENDOFLIFE       0x00200000
+#define DLM_IFL_WATCH_TIMEWARN  0x00400000
 #define DLM_IFL_USER            0x00000001
 #define DLM_IFL_ORPHAN          0x00000002
+#define DLM_IFL_TIMEOUT_CANCEL  0x00000004
 
 struct dlm_lkb {
         struct dlm_rsb          *lkb_resource;  /* the rsb */
@@ -243,6 +245,9 @@ struct dlm_lkb {
         struct list_head        lkb_wait_reply; /* waiting for remote reply */
         struct list_head        lkb_astqueue;   /* need ast to be sent */
         struct list_head        lkb_ownqueue;   /* list of locks for a process */
+        struct list_head        lkb_time_list;
+        unsigned long           lkb_timestamp;
+        unsigned long           lkb_timeout_cs;
 
         char                    *lkb_lvbptr;
         struct dlm_lksb         *lkb_lksb;      /* caller's status block */
@@ -447,6 +452,9 @@ struct dlm_ls {
         struct mutex            ls_orphans_mutex;
         struct list_head        ls_orphans;
 
+        struct mutex            ls_timeout_mutex;
+        struct list_head        ls_timeout;
+
         struct list_head        ls_nodes;       /* current nodes in ls */
         struct list_head        ls_nodes_gone;  /* dead node list, recovery */
         int                     ls_num_nodes;   /* number of nodes in ls */
@@ -472,6 +480,7 @@ struct dlm_ls {
         struct task_struct      *ls_recoverd_task;
         struct mutex            ls_recoverd_active;
         spinlock_t              ls_recover_lock;
+        unsigned long           ls_recover_begin; /* jiffies timestamp */
         uint32_t                ls_recover_status; /* DLM_RS_ */
         uint64_t                ls_recover_seq;
         struct dlm_recover      *ls_recover_args;
@@ -501,6 +510,7 @@ struct dlm_ls {
 #define LSFL_RCOM_READY         3
 #define LSFL_RCOM_WAIT          4
 #define LSFL_UEVENT_WAIT        5
+#define LSFL_TIMEWARN           6
 
 /* much of this is just saving user space pointers associated with the
    lock that we pass back to the user lib with an ast */