lslocks: add BLOCKER column

 BLOCKER -  PID of the process blocking the lock

Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/misc-utils/lslocks.8 b/misc-utils/lslocks.8
index 518ff0fbaae381137730d4ca66017cbccf8a3cca..8881c8c571d072b6340ec46af10a7a07cc773b03 100644 (file)
--- a/misc-utils/lslocks.8
+++ b/misc-utils/lslocks.8
@@ -61,6 +61,9 @@ will fallback to the device's mountpoint. The path might be truncated, use
 .B "--notruncate"
 to get the full path.
 
+.IP "BLOCKER"
+Process ID which blocks the lock.
+
 .SH NOTES
 .nf
 The lslocks command is meant to replace the lslk(8) command, originally written by

diff --git a/misc-utils/lslocks.c b/misc-utils/lslocks.c
index fb40dcb73d800a84685bfed18c3a1749036ede73..7c0637bf098062d103ac3af9caefff63686b4446 100644 (file)
--- a/misc-utils/lslocks.c
+++ b/misc-utils/lslocks.c
@@ -55,6 +55,7 @@ enum {
        COL_START,
        COL_END,
        COL_PATH,
+       COL_BLOCKER
 };
 
 /* column names */
@@ -76,6 +77,7 @@ static struct colinfo infos[] = {
        [COL_START] = { "START", 10, TT_FL_RIGHT, N_("relative byte offset of the lock")},
        [COL_END]  = { "END",    10, TT_FL_RIGHT, N_("ending offset of the lock")},
        [COL_PATH] = { "PATH",    0, TT_FL_TRUNC, N_("path of the locked file")},
+       [COL_BLOCKER] = { "BLOCKER", 0, TT_FL_RIGHT, N_("PID of the process blocking the lock") }
 };
 #define NCOLS ARRAY_SIZE(infos)
 static int columns[NCOLS], ncolumns;
@@ -96,6 +98,7 @@ struct lock {
        unsigned int mandatory :1,
                     blocked   :1;
        char *size;
+       int id;
 };
 
 static void disable_columns_truncate(void)
@@ -248,7 +251,9 @@ static int get_local_locks(struct list_head *locks)
                         * separated by ' ' - check <kernel>/fs/locks.c
                         */
                        switch (i) {
-                       case 0: /* ignore */
+                       case 0: /* ID: */
+                               tok[strlen(tok) - 1] = '\0';
+                               l->id = strtos32_or_err(tok, _("failed to parse ID"));
                                break;
                        case 1: /* posix, flock, etc */
                                if (strcmp(tok, "->") == 0) {   /* optional field */
@@ -306,22 +311,6 @@ static int get_local_locks(struct list_head *locks)
                        free(szstr);
                }
 
-               if (pid && pid != l->pid) {
-                       /*
-                        * It's easier to just parse the file then decide if
-                        * it should be added to the list - otherwise just
-                        * get rid of stored data
-                        */
-                       free(l->path);
-                       free(l->size);
-                       free(l->mode);
-                       free(l->cmdname);
-                       free(l->type);
-                       free(l);
-
-                       continue;
-               }
-
                list_add(&l->locks, locks);
        }
 
@@ -374,7 +363,21 @@ static void rem_lock(struct lock *lock)
        free(lock);
 }
 
-static void add_tt_line(struct tt *tt, struct lock *l)
+static pid_t get_blocker(int id, struct list_head *locks)
+{
+       struct list_head *p;
+
+       list_for_each(p, locks) {
+               struct lock *l = list_entry(p, struct lock, locks);
+
+               if (l->id == id && !l->blocked)
+                       return l->pid;
+       }
+
+       return 0;
+}
+
+static void add_tt_line(struct tt *tt, struct lock *l, struct list_head *locks)
 {
        int i;
        struct tt_line *line;
@@ -425,6 +428,13 @@ static void add_tt_line(struct tt *tt, struct lock *l)
                case COL_PATH:
                        xasprintf(&str, "%s", l->path ? l->path : notfnd);
                        break;
+               case COL_BLOCKER:
+               {
+                       pid_t bl = l->blocked && l->id ?
+                                               get_blocker(l->id, locks) : 0;
+                       if (bl)
+                               xasprintf(&str, "%d", (int) bl);
+               }
                default:
                        break;
                }
@@ -456,10 +466,20 @@ static int show_locks(struct list_head *locks, int tt_flags)
                }
        }
 
+       /* prepare data for output */
+       list_for_each(p, locks) {
+               struct lock *l = list_entry(p, struct lock, locks);
+
+               if (pid && pid != l->pid)
+                       continue;
+
+               add_tt_line(tt, l, locks);
+       }
+
+       /* destroy the list */
        list_for_each_safe(p, pnext, locks) {
-               struct lock *lock = list_entry(p, struct lock, locks);
-               add_tt_line(tt, lock);
-               rem_lock(lock);
+               struct lock *l = list_entry(p, struct lock, locks);
+               rem_lock(l);
        }
 
        tt_print_table(tt);