Merge tag 'nfsd-5.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux

[sfrench/cifs-2.6.git] / fs / locks.c

diff --git a/fs/locks.c b/fs/locks.c
index bcc71c469ede462048a2c17cbeff4a5333ff912b..74b2a1dfe8d87e4b12b014a51cb45bd6284f75a2 100644 (file)
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -2372,7 +2372,6 @@ int fcntl_getlk(struct file *filp, unsigned int cmd, struct flock *flock)
                if (flock->l_pid != 0)
                        goto out;
 
-               cmd = F_GETLK;
                fl->fl_flags |= FL_OFDLCK;
                fl->fl_owner = filp;
        }
@@ -2828,7 +2827,7 @@ struct locks_iterator {
 };
 
 static void lock_get_status(struct seq_file *f, struct file_lock *fl,
-                           loff_t id, char *pfx)
+                           loff_t id, char *pfx, int repeat)
 {
        struct inode *inode = NULL;
        unsigned int fl_pid;
@@ -2844,7 +2843,11 @@ static void lock_get_status(struct seq_file *f, struct file_lock *fl,
        if (fl->fl_file != NULL)
                inode = locks_inode(fl->fl_file);
 
-       seq_printf(f, "%lld:%s ", id, pfx);
+       seq_printf(f, "%lld: ", id);
+
+       if (repeat)
+               seq_printf(f, "%*s", repeat - 1 + (int)strlen(pfx), pfx);
+
        if (IS_POSIX(fl)) {
                if (fl->fl_flags & FL_ACCESS)
                        seq_puts(f, "ACCESS");
@@ -2906,21 +2909,64 @@ static void lock_get_status(struct seq_file *f, struct file_lock *fl,
        }
 }
 
+static struct file_lock *get_next_blocked_member(struct file_lock *node)
+{
+       struct file_lock *tmp;
+
+       /* NULL node or root node */
+       if (node == NULL || node->fl_blocker == NULL)
+               return NULL;
+
+       /* Next member in the linked list could be itself */
+       tmp = list_next_entry(node, fl_blocked_member);
+       if (list_entry_is_head(tmp, &node->fl_blocker->fl_blocked_requests, fl_blocked_member)
+               || tmp == node) {
+               return NULL;
+       }
+
+       return tmp;
+}
+
 static int locks_show(struct seq_file *f, void *v)
 {
        struct locks_iterator *iter = f->private;
-       struct file_lock *fl, *bfl;
+       struct file_lock *cur, *tmp;
        struct pid_namespace *proc_pidns = proc_pid_ns(file_inode(f->file)->i_sb);
+       int level = 0;
 
-       fl = hlist_entry(v, struct file_lock, fl_link);
+       cur = hlist_entry(v, struct file_lock, fl_link);
 
-       if (locks_translate_pid(fl, proc_pidns) == 0)
+       if (locks_translate_pid(cur, proc_pidns) == 0)
                return 0;
 
-       lock_get_status(f, fl, iter->li_pos, "");
+       /* View this crossed linked list as a binary tree, the first member of fl_blocked_requests
+        * is the left child of current node, the next silibing in fl_blocked_member is the
+        * right child, we can alse get the parent of current node from fl_blocker, so this
+        * question becomes traversal of a binary tree
+        */
+       while (cur != NULL) {
+               if (level)
+                       lock_get_status(f, cur, iter->li_pos, "-> ", level);
+               else
+                       lock_get_status(f, cur, iter->li_pos, "", level);
 
-       list_for_each_entry(bfl, &fl->fl_blocked_requests, fl_blocked_member)
-               lock_get_status(f, bfl, iter->li_pos, " ->");
+               if (!list_empty(&cur->fl_blocked_requests)) {
+                       /* Turn left */
+                       cur = list_first_entry_or_null(&cur->fl_blocked_requests,
+                               struct file_lock, fl_blocked_member);
+                       level++;
+               } else {
+                       /* Turn right */
+                       tmp = get_next_blocked_member(cur);
+                       /* Fall back to parent node */
+                       while (tmp == NULL && cur->fl_blocker != NULL) {
+                               cur = cur->fl_blocker;
+                               level--;
+                               tmp = get_next_blocked_member(cur);
+                       }
+                       cur = tmp;
+               }
+       }
 
        return 0;
 }
@@ -2941,7 +2987,7 @@ static void __show_fd_locks(struct seq_file *f,
 
                (*id)++;
                seq_puts(f, "lock:\t");
-               lock_get_status(f, fl, *id, "");
+               lock_get_status(f, fl, *id, "", 0);
        }
 }