From b4df2b92d8461444fac429c75ba6e125c63056bc Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Mon, 27 Oct 2008 22:48:36 +0300 Subject: proc: stop using BKL There are four BKL users in proc: de_put(), proc_lookup_de(), proc_readdir_de(), proc_root_readdir(), 1) de_put() ----------- de_put() is classic atomic_dec_and_test() refcount wrapper -- no BKL needed. BKL doesn't matter to possible refcount leak as well. 2) proc_lookup_de() ------------------- Walking PDE list is protected by proc_subdir_lock(), proc_get_inode() is potentially blocking, all callers of proc_lookup_de() eventually end up from ->lookup hooks which is protected by directory's ->i_mutex -- BKL doesn't protect anything. 3) proc_readdir_de() -------------------- "." and ".." part doesn't need BKL, walking PDE list is under proc_subdir_lock, calling filldir callback is potentially blocking because it writes to luserspace. All proc_readdir_de() callers eventually come from ->readdir hook which is under directory's ->i_mutex -- BKL doesn't protect anything. 4) proc_root_readdir_de() ------------------------- proc_root_readdir_de is ->readdir hook, see (3). Since readdir hooks doesn't use BKL anymore, switch to generic_file_llseek, since it also takes directory's i_mutex. Signed-off-by: Alexey Dobriyan --- fs/proc/root.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) (limited to 'fs/proc/root.c') diff --git a/fs/proc/root.c b/fs/proc/root.c index 7761602af9de..f6299a25594e 100644 --- a/fs/proc/root.c +++ b/fs/proc/root.c @@ -16,7 +16,6 @@ #include #include #include -#include #include #include @@ -162,17 +161,12 @@ static int proc_root_readdir(struct file * filp, unsigned int nr = filp->f_pos; int ret; - lock_kernel(); - if (nr < FIRST_PROCESS_ENTRY) { int error = proc_readdir(filp, dirent, filldir); - if (error <= 0) { - unlock_kernel(); + if (error <= 0) return error; - } filp->f_pos = FIRST_PROCESS_ENTRY; } - unlock_kernel(); ret = proc_pid_readdir(filp, dirent, filldir); return ret; -- cgit v1.2.3-58-ga151