From 3663df70c028bc435d6f2ec532a4849db62d1656 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Wed, 19 May 2010 15:08:17 +0200 Subject: autofs4: Pushdown the bkl from ioctl Pushdown the bkl to autofs4_root_ioctl. Signed-off-by: Frederic Weisbecker Cc: Ian Kent Cc: Autofs Cc: Thomas Gleixner Cc: John Kacur Cc: Arnd Bergmann --- fs/autofs4/root.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) (limited to 'fs/autofs4') diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c index e8e5e63..db4117e 100644 --- a/fs/autofs4/root.c +++ b/fs/autofs4/root.c @@ -18,13 +18,14 @@ #include #include #include +#include #include "autofs_i.h" static int autofs4_dir_symlink(struct inode *,struct dentry *,const char *); static int autofs4_dir_unlink(struct inode *,struct dentry *); static int autofs4_dir_rmdir(struct inode *,struct dentry *); static int autofs4_dir_mkdir(struct inode *,struct dentry *,int); -static int autofs4_root_ioctl(struct inode *, struct file *,unsigned int,unsigned long); +static long autofs4_root_ioctl(struct file *,unsigned int,unsigned long); static int autofs4_dir_open(struct inode *inode, struct file *file); static struct dentry *autofs4_lookup(struct inode *,struct dentry *, struct nameidata *); static void *autofs4_follow_link(struct dentry *, struct nameidata *); @@ -38,7 +39,7 @@ const struct file_operations autofs4_root_operations = { .read = generic_read_dir, .readdir = dcache_readdir, .llseek = dcache_dir_lseek, - .ioctl = autofs4_root_ioctl, + .unlocked_ioctl = autofs4_root_ioctl, }; const struct file_operations autofs4_dir_operations = { @@ -902,8 +903,8 @@ int is_autofs4_dentry(struct dentry *dentry) * ioctl()'s on the root directory is the chief method for the daemon to * generate kernel reactions */ -static int autofs4_root_ioctl(struct inode *inode, struct file *filp, - unsigned int cmd, unsigned long arg) +static int autofs4_root_ioctl_unlocked(struct inode *inode, struct file *filp, + unsigned int cmd, unsigned long arg) { struct autofs_sb_info *sbi = autofs4_sbi(inode->i_sb); void __user *p = (void __user *)arg; @@ -947,3 +948,16 @@ static int autofs4_root_ioctl(struct inode *inode, struct file *filp, return -ENOSYS; } } + +static long autofs4_root_ioctl(struct file *filp, + unsigned int cmd, unsigned long arg) +{ + long ret; + struct inode *inode = filp->f_dentry->d_inode; + + lock_kernel(); + ret = autofs4_root_ioctl_unlocked(inode, filp, cmd, arg); + unlock_kernel(); + + return ret; +} -- cgit v1.1 From 578454ff7eab61d13a26b568f99a89a2c9edc881 Mon Sep 17 00:00:00 2001 From: Kay Sievers Date: Thu, 20 May 2010 18:07:20 +0200 Subject: driver core: add devname module aliases to allow module on-demand auto-loading This adds: alias: devname: to some common kernel modules, which will allow the on-demand loading of the kernel module when the device node is accessed. Ideally all these modules would be compiled-in, but distros seems too much in love with their modularization that we need to cover the common cases with this new facility. It will allow us to remove a bunch of pretty useless init scripts and modprobes from init scripts. The static device node aliases will be carried in the module itself. The program depmod will extract this information to a file in the module directory: $ cat /lib/modules/2.6.34-00650-g537b60d-dirty/modules.devname # Device nodes to trigger on-demand module loading. microcode cpu/microcode c10:184 fuse fuse c10:229 ppp_generic ppp c108:0 tun net/tun c10:200 dm_mod mapper/control c10:235 Udev will pick up the depmod created file on startup and create all the static device nodes which the kernel modules specify, so that these modules get automatically loaded when the device node is accessed: $ /sbin/udevd --debug ... static_dev_create_from_modules: mknod '/dev/cpu/microcode' c10:184 static_dev_create_from_modules: mknod '/dev/fuse' c10:229 static_dev_create_from_modules: mknod '/dev/ppp' c108:0 static_dev_create_from_modules: mknod '/dev/net/tun' c10:200 static_dev_create_from_modules: mknod '/dev/mapper/control' c10:235 udev_rules_apply_static_dev_perms: chmod '/dev/net/tun' 0666 udev_rules_apply_static_dev_perms: chmod '/dev/fuse' 0666 A few device nodes are switched to statically allocated numbers, to allow the static nodes to work. This might also useful for systems which still run a plain static /dev, which is completely unsafe to use with any dynamic minor numbers. Note: The devname aliases must be limited to the *common* and *single*instance* device nodes, like the misc devices, and never be used for conceptually limited systems like the loop devices, which should rather get fixed properly and get a control node for losetup to talk to, instead of creating a random number of device nodes in advance, regardless if they are ever used. This facility is to hide the mess distros are creating with too modualized kernels, and just to hide that these modules are not compiled-in, and not to paper-over broken concepts. Thanks! :) Cc: Greg Kroah-Hartman Cc: David S. Miller Cc: Miklos Szeredi Cc: Chris Mason Cc: Alasdair G Kergon Cc: Tigran Aivazian Cc: Ian Kent Signed-Off-By: Kay Sievers Signed-off-by: Greg Kroah-Hartman --- fs/autofs4/dev-ioctl.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'fs/autofs4') diff --git a/fs/autofs4/dev-ioctl.c b/fs/autofs4/dev-ioctl.c index d29b7f6..d832062 100644 --- a/fs/autofs4/dev-ioctl.c +++ b/fs/autofs4/dev-ioctl.c @@ -736,11 +736,14 @@ static const struct file_operations _dev_ioctl_fops = { }; static struct miscdevice _autofs_dev_ioctl_misc = { - .minor = MISC_DYNAMIC_MINOR, + .minor = AUTOFS_MINOR, .name = AUTOFS_DEVICE_NAME, .fops = &_dev_ioctl_fops }; +MODULE_ALIAS_MISCDEV(AUTOFS_MINOR); +MODULE_ALIAS("devname:autofs"); + /* Register/deregister misc character device */ int autofs_dev_ioctl_init(void) { -- cgit v1.1 From 7ca5ca60cba37fc4d8e99583da147faed3039ad0 Mon Sep 17 00:00:00 2001 From: Julia Lawall Date: Wed, 26 May 2010 14:42:13 -0700 Subject: fs/autofs4: use memdup_user Use memdup_user when user data is immediately copied into the allocated region. Elimination of the variable ads, which is no longer useful. The semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // @@ expression from,to,size,flag; position p; identifier l1,l2; @@ - to = \(kmalloc@p\|kzalloc@p\)(size,flag); + to = memdup_user(from,size); if ( - to==NULL + IS_ERR(to) || ...) { <+... when != goto l1; - -ENOMEM + PTR_ERR(to) ...+> } - if (copy_from_user(to, from, size) != 0) { - <+... when != goto l2; - -EFAULT - ...+> - } // Signed-off-by: Julia Lawall Cc: Ian Kent Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/autofs4/dev-ioctl.c | 13 ++----------- 1 file changed, 2 insertions(+), 11 deletions(-) (limited to 'fs/autofs4') diff --git a/fs/autofs4/dev-ioctl.c b/fs/autofs4/dev-ioctl.c index d832062..ba4a38b 100644 --- a/fs/autofs4/dev-ioctl.c +++ b/fs/autofs4/dev-ioctl.c @@ -95,7 +95,7 @@ static int check_dev_ioctl_version(int cmd, struct autofs_dev_ioctl *param) */ static struct autofs_dev_ioctl *copy_dev_ioctl(struct autofs_dev_ioctl __user *in) { - struct autofs_dev_ioctl tmp, *ads; + struct autofs_dev_ioctl tmp; if (copy_from_user(&tmp, in, sizeof(tmp))) return ERR_PTR(-EFAULT); @@ -103,16 +103,7 @@ static struct autofs_dev_ioctl *copy_dev_ioctl(struct autofs_dev_ioctl __user *i if (tmp.size < sizeof(tmp)) return ERR_PTR(-EINVAL); - ads = kmalloc(tmp.size, GFP_KERNEL); - if (!ads) - return ERR_PTR(-ENOMEM); - - if (copy_from_user(ads, in, tmp.size)) { - kfree(ads); - return ERR_PTR(-EFAULT); - } - - return ads; + return memdup_user(in, tmp.size); } static inline void free_dev_ioctl(struct autofs_dev_ioctl *param) -- cgit v1.1