From f649d6d32605c7573884613289fb3b9fbd4f99a1 Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Tue, 29 Apr 2008 01:01:39 -0700 Subject: proc: simplify locking in remove_proc_entry() proc_subdir_lock protects only modifying and walking through PDE lists, so after we've found PDE to remove and actually removed it from lists, there is no need to hold proc_subdir_lock for the rest of operation. Signed-off-by: Alexey Dobriyan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/proc/generic.c | 82 +++++++++++++++++++++++++++---------------------------- 1 file changed, 40 insertions(+), 42 deletions(-) (limited to 'fs/proc/generic.c') diff --git a/fs/proc/generic.c b/fs/proc/generic.c index f501f3211ab..45d0076bc08 100644 --- a/fs/proc/generic.c +++ b/fs/proc/generic.c @@ -734,60 +734,58 @@ void free_proc_entry(struct proc_dir_entry *de) void remove_proc_entry(const char *name, struct proc_dir_entry *parent) { struct proc_dir_entry **p; - struct proc_dir_entry *de; + struct proc_dir_entry *de = NULL; const char *fn = name; int len; if (!parent && xlate_proc_name(name, &parent, &fn) != 0) - goto out; + return; len = strlen(fn); spin_lock(&proc_subdir_lock); for (p = &parent->subdir; *p; p=&(*p)->next ) { - if (!proc_match(len, fn, *p)) - continue; - de = *p; - *p = de->next; - de->next = NULL; - - spin_lock(&de->pde_unload_lock); - /* - * Stop accepting new callers into module. If you're - * dynamically allocating ->proc_fops, save a pointer somewhere. - */ - de->proc_fops = NULL; - /* Wait until all existing callers into module are done. */ - if (de->pde_users > 0) { - DECLARE_COMPLETION_ONSTACK(c); - - if (!de->pde_unload_completion) - de->pde_unload_completion = &c; - - spin_unlock(&de->pde_unload_lock); - spin_unlock(&proc_subdir_lock); + if (proc_match(len, fn, *p)) { + de = *p; + *p = de->next; + de->next = NULL; + break; + } + } + spin_unlock(&proc_subdir_lock); + if (!de) + return; - wait_for_completion(de->pde_unload_completion); + spin_lock(&de->pde_unload_lock); + /* + * Stop accepting new callers into module. If you're + * dynamically allocating ->proc_fops, save a pointer somewhere. + */ + de->proc_fops = NULL; + /* Wait until all existing callers into module are done. */ + if (de->pde_users > 0) { + DECLARE_COMPLETION_ONSTACK(c); + + if (!de->pde_unload_completion) + de->pde_unload_completion = &c; - spin_lock(&proc_subdir_lock); - goto continue_removing; - } spin_unlock(&de->pde_unload_lock); + wait_for_completion(de->pde_unload_completion); + + goto continue_removing; + } + spin_unlock(&de->pde_unload_lock); + continue_removing: - if (S_ISDIR(de->mode)) - parent->nlink--; - de->nlink = 0; - if (de->subdir) { - printk(KERN_WARNING "%s: removing non-empty directory " - "'%s/%s', leaking at least '%s'\n", __func__, - de->parent->name, de->name, de->subdir->name); - WARN_ON(1); - } - if (atomic_dec_and_test(&de->count)) - free_proc_entry(de); - break; + if (S_ISDIR(de->mode)) + parent->nlink--; + de->nlink = 0; + if (de->subdir) { + printk(KERN_WARNING "%s: removing non-empty directory " + "'%s/%s', leaking at least '%s'\n", __func__, + de->parent->name, de->name, de->subdir->name); + WARN_ON(1); } - spin_unlock(&proc_subdir_lock); -out: - return; + if (atomic_dec_and_test(&de->count)) + free_proc_entry(de); } -- cgit v1.2.3