lkml.org 
[lkml]   [2021]   [Feb]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2 02/24] fs/locks: print full locks information
Date
Commit fd7732e033e3 ("fs/locks: create a tree of dependent requests.")
has put blocked locks into a tree.

So, with a for loop, we can't check all locks information.

To solve this problem, we should traverse the tree by non-recursion DFS.

Signed-off-by: Luo Longjun <luolongjun@huawei.com>
---
fs/locks.c | 75 ++++++++++++++++++++++++++++++++++++++++++++++++------
1 file changed, 67 insertions(+), 8 deletions(-)

diff --git a/fs/locks.c b/fs/locks.c
index 99ca97e81b7a..fdf240626777 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -2827,8 +2827,14 @@ struct locks_iterator {
loff_t li_pos;
};

+struct locks_traverse_list {
+ struct list_head head;
+ struct file_lock *lock;
+ int level;
+};
+
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 +2850,11 @@ 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 + strlen(pfx), pfx);
+
if (IS_POSIX(fl)) {
if (fl->fl_flags & FL_ACCESS)
seq_puts(f, "ACCESS");
@@ -2912,17 +2922,66 @@ static int locks_show(struct seq_file *f, void *v)
struct file_lock *fl, *bfl;
struct pid_namespace *proc_pidns = proc_pid_ns(file_inode(f->file)->i_sb);

+ struct list_head root;
+ struct list_head *tail = &root;
+ struct list_head *pos, *tmp;
+ struct locks_traverse_list *node, *node_child;
+
+ int ret = 0;
+
fl = hlist_entry(v, struct file_lock, fl_link);

if (locks_translate_pid(fl, proc_pidns) == 0)
- return 0;
+ return ret;
+
+ INIT_LIST_HEAD(&root);

- lock_get_status(f, fl, iter->li_pos, "");
+ node = kmalloc(sizeof(struct locks_traverse_list), GFP_KERNEL);
+ if (!node) {
+ ret = -ENOMEM;
+ goto out;
+ }

- list_for_each_entry(bfl, &fl->fl_blocked_requests, fl_blocked_member)
- lock_get_status(f, bfl, iter->li_pos, " ->");
+ node->level = 0;
+ node->lock = fl;
+ list_add(&node->head, tail);
+ tail = &node->head;

- return 0;
+ while (tail != &root) {
+ node = list_entry(tail, struct locks_traverse_list, head);
+ if (!node->level)
+ lock_get_status(f, node->lock, iter->li_pos, "", node->level);
+ else
+ lock_get_status(f, node->lock, iter->li_pos, "-> ", node->level);
+
+ tmp = tail->prev;
+ list_del(tail);
+ tail = tmp;
+
+ list_for_each_entry_reverse(bfl, &node->lock->fl_blocked_requests,
+ fl_blocked_member) {
+ node_child = kmalloc(sizeof(struct locks_traverse_list), GFP_KERNEL);
+ if (!node_child) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ node_child->level = node->level + 1;
+ node_child->lock = bfl;
+ list_add(&node_child->head, tail);
+ tail = &node_child->head;
+ }
+ kfree(node);
+ }
+
+out:
+ list_for_each_safe(pos, tmp, &root) {
+ node = list_entry(pos, struct locks_traverse_list, head);
+ list_del(pos);
+ if (!node)
+ kfree(node);
+ }
+ return ret;
}

static void __show_fd_locks(struct seq_file *f,
@@ -2941,7 +3000,7 @@ 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);
}
}

--
2.17.1
\
 
 \ /
  Last update: 2021-02-24 12:30    [W:0.146 / U:0.072 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site