From b8da9b10e26cee58eba7b0fd72717127edfb316b Mon Sep 17 00:00:00 2001 From: Luo Longjun Date: Thu, 25 Feb 2021 22:58:29 -0500 Subject: fs/locks: print full locks information 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. Signed-off-by: Luo Longjun Signed-off-by: Jeff Layton --- fs/locks.c | 65 +++++++++++++++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 56 insertions(+), 9 deletions(-) (limited to 'fs/locks.c') diff --git a/fs/locks.c b/fs/locks.c index 99ca97e81b7a..ecaecd1f1b58 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -2828,7 +2828,7 @@ 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 +2844,11 @@ 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 +2910,64 @@ 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 +2988,7 @@ 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); } } -- cgit From cbe6fc4e01421c890d74422cdd04c6b1c8f62dda Mon Sep 17 00:00:00 2001 From: Tian Tao Date: Tue, 13 Apr 2021 09:58:23 +0800 Subject: fs/locks: remove useless assignment in fcntl_getlk Function parameter 'cmd' is rewritten with unused value at locks.c Signed-off-by: Tian Tao Signed-off-by: Jeff Layton --- fs/locks.c | 1 - 1 file changed, 1 deletion(-) (limited to 'fs/locks.c') diff --git a/fs/locks.c b/fs/locks.c index ecaecd1f1b58..003873da17e2 100644 --- 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; } -- cgit