From 9fd5746fd3d7838bf6ff991d50f1257057d1156f Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Thu, 21 May 2009 16:01:00 -0400 Subject: fs: Remove i_cindex from struct inode The only user of the i_cindex element in the inode structure is used is by the firewire drivers. As part of an attempt to slim down the inode structure to save memory --- since a typical Linux system will have hundreds of thousands if not millions of inodes cached, a reduction in the size inode has high leverage. The firewire driver does not need i_cindex in any fast path, so it's simple enough to calculate when it is needed, instead of wasting space in the inode structure. Signed-off-by: "Theodore Ts'o" Cc: krh@redhat.com Cc: stefanr@s5r6.in-berlin.de Cc: linux-fsdevel@vger.kernel.org Signed-off-by: Al Viro --- fs/char_dev.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) (limited to 'fs/char_dev.c') diff --git a/fs/char_dev.c b/fs/char_dev.c index 38f71222a552..b7c9d5187a75 100644 --- a/fs/char_dev.c +++ b/fs/char_dev.c @@ -375,7 +375,6 @@ static int chrdev_open(struct inode *inode, struct file *filp) p = inode->i_cdev; if (!p) { inode->i_cdev = p = new; - inode->i_cindex = idx; list_add(&inode->i_devices, &p->list); new = NULL; } else if (!cdev_get(p)) @@ -405,6 +404,18 @@ static int chrdev_open(struct inode *inode, struct file *filp) return ret; } +int cdev_index(struct inode *inode) +{ + int idx; + struct kobject *kobj; + + kobj = kobj_lookup(cdev_map, inode->i_rdev, &idx); + if (!kobj) + return -1; + kobject_put(kobj); + return idx; +} + void cd_forget(struct inode *inode) { spin_lock(&cdev_lock); @@ -557,6 +568,7 @@ EXPORT_SYMBOL(cdev_init); EXPORT_SYMBOL(cdev_alloc); EXPORT_SYMBOL(cdev_del); EXPORT_SYMBOL(cdev_add); +EXPORT_SYMBOL(cdev_index); EXPORT_SYMBOL(register_chrdev); EXPORT_SYMBOL(unregister_chrdev); EXPORT_SYMBOL(directly_mappable_cdev_bdi); -- cgit