Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755310Ab0GKVV5 (ORCPT ); Sun, 11 Jul 2010 17:21:57 -0400 Received: from moutng.kundenserver.de ([212.227.17.8]:55221 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753951Ab0GKVTM (ORCPT ); Sun, 11 Jul 2010 17:19:12 -0400 From: Arnd Bergmann To: linux-kernel@vger.kernel.org Cc: John Kacur , Frederic Weisbecker , Arnd Bergmann , "David S. Miller" , netdev@vger.kernel.org Subject: [PATCH 06/12] net: autoconvert trivial BKL users to private mutex Date: Sun, 11 Jul 2010 23:18:57 +0200 Message-Id: <1278883143-29035-7-git-send-email-arnd@arndb.de> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1278883143-29035-1-git-send-email-arnd@arndb.de> References: <1278883143-29035-1-git-send-email-arnd@arndb.de> X-Provags-ID: V02:K0:h44emQBWQeS4EWlsNellNSJO2wb3Qsv3OXQdCVfJIKu AZ+wuYWO3zB9gBQWZajd3FOj0tPfBKHPRE7YmIpeuNGvN0uH1h 7MvSK1FBpW82X8KWvC1kmZcXtIEZL2SVf4gIfzCKUSSGQfQpnP M1J/ogJqBIrYBAJlrHd+rhn6zMnAjBvAwPLHKWTZfN608c6uVZ OMzRaXMTd88SRbSrdyQQA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8305 Lines: 283 All these files use the big kernel lock in a trivial way to serialize their private file operations, typically resulting from an earlier semi-automatic pushdown from VFS. None of these drivers appears to want to lock against other code, and they all use the BKL as the top-level lock in their file operations, meaning that there is no lock-order inversion problem. Consequently, we can remove the BKL completely, replacing it with a per-file mutex in every case. Using a scripted approach means we can avoid typos. file=$1 name=$2 if grep -q lock_kernel ${file} ; then if grep -q 'include.*linux.mutex.h' ${file} ; then sed -i '/include.*/d' ${file} else sed -i 's/include.*.*$/include /g' ${file} fi sed -i ${file} \ -e "/^#include.*linux.mutex.h/,$ { 1,/^\(static\|int\|long\)/ { /^\(static\|int\|long\)/istatic DEFINE_MUTEX(${name}_mutex); } }" \ -e "s/\(un\)*lock_kernel\>[ ]*()/mutex_\1lock(\&${name}_mutex)/g" \ -e '/[ ]*cycle_kernel_lock();/d' else sed -i -e '/include.*\/d' ${file} \ -e '/cycle_kernel_lock()/d' fi Signed-off-by: Arnd Bergmann Cc: "David S. Miller" Cc: netdev@vger.kernel.org --- drivers/net/ppp_generic.c | 19 +++++++++---------- drivers/net/wan/cosa.c | 10 +++++----- net/wanrouter/wanmain.c | 7 ++++--- net/wanrouter/wanproc.c | 7 ++++--- 4 files changed, 22 insertions(+), 21 deletions(-) diff --git a/drivers/net/ppp_generic.c b/drivers/net/ppp_generic.c index 1b2c291..a72a335 100644 --- a/drivers/net/ppp_generic.c +++ b/drivers/net/ppp_generic.c @@ -40,7 +40,6 @@ #include #include #include -#include #include #include #include @@ -181,6 +180,7 @@ struct channel { * channel.downl. */ +static DEFINE_MUTEX(ppp_mutex); static atomic_t ppp_unit_count = ATOMIC_INIT(0); static atomic_t channel_count = ATOMIC_INIT(0); @@ -363,7 +363,6 @@ static const int npindex_to_ethertype[NUM_NP] = { */ static int ppp_open(struct inode *inode, struct file *file) { - cycle_kernel_lock(); /* * This could (should?) be enforced by the permissions on /dev/ppp. */ @@ -588,7 +587,7 @@ static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) * this fd and reopening /dev/ppp. */ err = -EINVAL; - lock_kernel(); + mutex_lock(&ppp_mutex); if (pf->kind == INTERFACE) { ppp = PF_TO_PPP(pf); if (file == ppp->owner) @@ -600,7 +599,7 @@ static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) } else printk(KERN_DEBUG "PPPIOCDETACH file->f_count=%ld\n", atomic_long_read(&file->f_count)); - unlock_kernel(); + mutex_unlock(&ppp_mutex); return err; } @@ -608,7 +607,7 @@ static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) struct channel *pch; struct ppp_channel *chan; - lock_kernel(); + mutex_lock(&ppp_mutex); pch = PF_TO_CHANNEL(pf); switch (cmd) { @@ -630,7 +629,7 @@ static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) err = chan->ops->ioctl(chan, cmd, arg); up_read(&pch->chan_sem); } - unlock_kernel(); + mutex_unlock(&ppp_mutex); return err; } @@ -640,7 +639,7 @@ static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) return -EINVAL; } - lock_kernel(); + mutex_lock(&ppp_mutex); ppp = PF_TO_PPP(pf); switch (cmd) { case PPPIOCSMRU: @@ -788,7 +787,7 @@ static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) default: err = -ENOTTY; } - unlock_kernel(); + mutex_unlock(&ppp_mutex); return err; } @@ -801,7 +800,7 @@ static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, struct ppp_net *pn; int __user *p = (int __user *)arg; - lock_kernel(); + mutex_lock(&ppp_mutex); switch (cmd) { case PPPIOCNEWUNIT: /* Create a new ppp unit */ @@ -852,7 +851,7 @@ static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, default: err = -ENOTTY; } - unlock_kernel(); + mutex_unlock(&ppp_mutex); return err; } diff --git a/drivers/net/wan/cosa.c b/drivers/net/wan/cosa.c index f0bd70f..04c6cd4 100644 --- a/drivers/net/wan/cosa.c +++ b/drivers/net/wan/cosa.c @@ -89,7 +89,6 @@ #include #include #include -#include #include #include #include @@ -174,6 +173,7 @@ struct cosa_data { * Character device major number. 117 was allocated for us. * The value of 0 means to allocate a first free one. */ +static DEFINE_MUTEX(cosa_chardev_mutex); static int cosa_major = 117; /* @@ -944,7 +944,7 @@ static int cosa_open(struct inode *inode, struct file *file) int n; int ret = 0; - lock_kernel(); + mutex_lock(&cosa_chardev_mutex); if ((n=iminor(file->f_path.dentry->d_inode)>>CARD_MINOR_BITS) >= nr_cards) { ret = -ENODEV; @@ -976,7 +976,7 @@ static int cosa_open(struct inode *inode, struct file *file) chan->rx_done = chrdev_rx_done; spin_unlock_irqrestore(&cosa->lock, flags); out: - unlock_kernel(); + mutex_unlock(&cosa_chardev_mutex); return ret; } @@ -1212,10 +1212,10 @@ static long cosa_chardev_ioctl(struct file *file, unsigned int cmd, struct cosa_data *cosa; long ret; - lock_kernel(); + mutex_lock(&cosa_chardev_mutex); cosa = channel->cosa; ret = cosa_ioctl_common(cosa, channel, cmd, arg); - unlock_kernel(); + mutex_unlock(&cosa_chardev_mutex); return ret; } diff --git a/net/wanrouter/wanmain.c b/net/wanrouter/wanmain.c index 258daa8..2bf2340 100644 --- a/net/wanrouter/wanmain.c +++ b/net/wanrouter/wanmain.c @@ -48,7 +48,7 @@ #include #include /* support for loadable modules */ #include /* kmalloc(), kfree() */ -#include +#include #include #include /* inline mem*, str* functions */ @@ -71,6 +71,7 @@ * WAN device IOCTL handlers */ +static DEFINE_MUTEX(wanrouter_mutex); static int wanrouter_device_setup(struct wan_device *wandev, wandev_conf_t __user *u_conf); static int wanrouter_device_stat(struct wan_device *wandev, @@ -376,7 +377,7 @@ long wanrouter_ioctl(struct file *file, unsigned int cmd, unsigned long arg) if (wandev->magic != ROUTER_MAGIC) return -EINVAL; - lock_kernel(); + mutex_lock(&wanrouter_mutex); switch (cmd) { case ROUTER_SETUP: err = wanrouter_device_setup(wandev, data); @@ -408,7 +409,7 @@ long wanrouter_ioctl(struct file *file, unsigned int cmd, unsigned long arg) err = wandev->ioctl(wandev, cmd, arg); else err = -EINVAL; } - unlock_kernel(); + mutex_unlock(&wanrouter_mutex); return err; } diff --git a/net/wanrouter/wanproc.c b/net/wanrouter/wanproc.c index c44d96b..11f25c7 100644 --- a/net/wanrouter/wanproc.c +++ b/net/wanrouter/wanproc.c @@ -27,7 +27,7 @@ #include #include /* WAN router API definitions */ #include -#include +#include #include #include @@ -66,6 +66,7 @@ * /proc/net/router */ +static DEFINE_MUTEX(config_mutex); static struct proc_dir_entry *proc_router; /* Strings */ @@ -85,7 +86,7 @@ static void *r_start(struct seq_file *m, loff_t *pos) struct wan_device *wandev; loff_t l = *pos; - lock_kernel(); + mutex_lock(&config_mutex); if (!l--) return SEQ_START_TOKEN; for (wandev = wanrouter_router_devlist; l-- && wandev; @@ -104,7 +105,7 @@ static void *r_next(struct seq_file *m, void *v, loff_t *pos) static void r_stop(struct seq_file *m, void *v) __releases(kernel_lock) { - unlock_kernel(); + mutex_unlock(&config_mutex); } static int config_show(struct seq_file *m, void *v) -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/