From e11e7ac1ecac6b25439c003c5ca661cd399ec35d Mon Sep 17 00:00:00 2001 From: Jan Kiszka Date: Mon, 8 Feb 2010 10:12:08 +0000 Subject: [PATCH] CAPI: Pin capifs instead of mounting it Auto-mounting the capifs during module init prevents unloading its module. Instead, pin the filesystem as long as some NCCI node exists. Signed-off-by: Jan Kiszka Signed-off-by: David S. Miller --- drivers/isdn/capi/capifs.c | 27 ++++++++++++++++++--------- 1 file changed, 18 insertions(+), 9 deletions(-) diff --git a/drivers/isdn/capi/capifs.c b/drivers/isdn/capi/capifs.c index 6ae0edf29c8..51c01efe2fe 100644 --- a/drivers/isdn/capi/capifs.c +++ b/drivers/isdn/capi/capifs.c @@ -32,6 +32,7 @@ static char *revision = "$Revision: 1.1.2.3 $"; #define CAPIFS_SUPER_MAGIC (('C'<<8)|'N') static struct vfsmount *capifs_mnt; +static int capifs_mnt_count; static struct { int setuid; @@ -140,7 +141,7 @@ static struct file_system_type capifs_fs_type = { .kill_sb = kill_anon_super, }; -struct dentry *capifs_new_ncci(unsigned int number, dev_t device) +static struct dentry *new_ncci(unsigned int number, dev_t device) { struct super_block *s = capifs_mnt->mnt_sb; struct dentry *root = s->s_root; @@ -187,6 +188,20 @@ unlock_out: return dentry; } +struct dentry *capifs_new_ncci(unsigned int number, dev_t device) +{ + struct dentry *dentry; + + if (simple_pin_fs(&capifs_fs_type, &capifs_mnt, &capifs_mnt_count) < 0) + return NULL; + + dentry = new_ncci(number, device); + if (!dentry) + simple_release_fs(&capifs_mnt, &capifs_mnt_count); + + return dentry; +} + void capifs_free_ncci(struct dentry *dentry) { struct dentry *root = capifs_mnt->mnt_sb->s_root; @@ -206,6 +221,8 @@ void capifs_free_ncci(struct dentry *dentry) dput(dentry); mutex_unlock(&root->d_inode->i_mutex); + + simple_release_fs(&capifs_mnt, &capifs_mnt_count); } static int __init capifs_init(void) @@ -222,13 +239,6 @@ static int __init capifs_init(void) strcpy(rev, "1.0"); err = register_filesystem(&capifs_fs_type); - if (!err) { - capifs_mnt = kern_mount(&capifs_fs_type); - if (IS_ERR(capifs_mnt)) { - err = PTR_ERR(capifs_mnt); - unregister_filesystem(&capifs_fs_type); - } - } if (!err) printk(KERN_NOTICE "capifs: Rev %s\n", rev); return err; @@ -237,7 +247,6 @@ static int __init capifs_init(void) static void __exit capifs_exit(void) { unregister_filesystem(&capifs_fs_type); - mntput(capifs_mnt); } EXPORT_SYMBOL(capifs_new_ncci);