[PATCH] inode_diet: Replace inode.u.generic_ip with inode.i_private
The following patches reduce the size of the VFS inode structure by 28 bytes
on a UP x86. (It would be more on an x86_64 system). This is a 10% reduction
in the inode size on a UP kernel that is configured in a production mode
(i.e., with no spinlock or other debugging functions enabled; if you want to
save memory taken up by in-core inodes, the first thing you should do is
disable the debugging options; they are responsible for a huge amount of bloat
in the VFS inode structure).
This patch:
The filesystem or device-specific pointer in the inode is inside a union,
which is pretty pointless given that all 30+ users of this field have been
using the void pointer. Get rid of the union and rename it to i_private, with
a comment to explain who is allowed to use the void pointer. This is just a
cleanup, but it allows us to reuse the union 'u' for something something where
the union will actually be used.
[judith@osdl.org: powerpc build fix]
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Judith Lebzelter <judith@osdl.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index 218621b..32e0300 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -555,7 +555,7 @@
if (imajor(inode) == USB_DEVICE_MAJOR)
dev = usbdev_lookup_minor(iminor(inode));
if (!dev)
- dev = inode->u.generic_ip;
+ dev = inode->i_private;
if (!dev) {
kfree(ps);
goto out;
diff --git a/drivers/usb/core/inode.c b/drivers/usb/core/inode.c
index 3182c22..482f253 100644
--- a/drivers/usb/core/inode.c
+++ b/drivers/usb/core/inode.c
@@ -402,8 +402,8 @@
static int default_open (struct inode *inode, struct file *file)
{
- if (inode->u.generic_ip)
- file->private_data = inode->u.generic_ip;
+ if (inode->i_private)
+ file->private_data = inode->i_private;
return 0;
}
@@ -509,7 +509,7 @@
} else {
if (dentry->d_inode) {
if (data)
- dentry->d_inode->u.generic_ip = data;
+ dentry->d_inode->i_private = data;
if (fops)
dentry->d_inode->i_fop = fops;
dentry->d_inode->i_uid = uid;
diff --git a/drivers/usb/gadget/inode.c b/drivers/usb/gadget/inode.c
index 3bdc5e3..ffaa8c1 100644
--- a/drivers/usb/gadget/inode.c
+++ b/drivers/usb/gadget/inode.c
@@ -844,7 +844,7 @@
static int
ep_open (struct inode *inode, struct file *fd)
{
- struct ep_data *data = inode->u.generic_ip;
+ struct ep_data *data = inode->i_private;
int value = -EBUSY;
if (down_interruptible (&data->lock) != 0)
@@ -1909,7 +1909,7 @@
static int
dev_open (struct inode *inode, struct file *fd)
{
- struct dev_data *dev = inode->u.generic_ip;
+ struct dev_data *dev = inode->i_private;
int value = -EBUSY;
if (dev->state == STATE_DEV_DISABLED) {
@@ -1970,7 +1970,7 @@
inode->i_blocks = 0;
inode->i_atime = inode->i_mtime = inode->i_ctime
= CURRENT_TIME;
- inode->u.generic_ip = data;
+ inode->i_private = data;
inode->i_fop = fops;
}
return inode;
diff --git a/drivers/usb/host/isp116x-hcd.c b/drivers/usb/host/isp116x-hcd.c
index 5147ed4..8c6b38a 100644
--- a/drivers/usb/host/isp116x-hcd.c
+++ b/drivers/usb/host/isp116x-hcd.c
@@ -1204,7 +1204,7 @@
static int isp116x_open_seq(struct inode *inode, struct file *file)
{
- return single_open(file, isp116x_show_dbg, inode->u.generic_ip);
+ return single_open(file, isp116x_show_dbg, inode->i_private);
}
static struct file_operations isp116x_debug_fops = {
diff --git a/drivers/usb/host/uhci-debug.c b/drivers/usb/host/uhci-debug.c
index dc286a4..d1372cb 100644
--- a/drivers/usb/host/uhci-debug.c
+++ b/drivers/usb/host/uhci-debug.c
@@ -428,7 +428,7 @@
static int uhci_debug_open(struct inode *inode, struct file *file)
{
- struct uhci_hcd *uhci = inode->u.generic_ip;
+ struct uhci_hcd *uhci = inode->i_private;
struct uhci_debug *up;
int ret = -ENOMEM;
unsigned long flags;
diff --git a/drivers/usb/mon/mon_stat.c b/drivers/usb/mon/mon_stat.c
index 1fe01d9..86ad2b3 100644
--- a/drivers/usb/mon/mon_stat.c
+++ b/drivers/usb/mon/mon_stat.c
@@ -28,7 +28,7 @@
if ((sp = kmalloc(sizeof(struct snap), GFP_KERNEL)) == NULL)
return -ENOMEM;
- mbus = inode->u.generic_ip;
+ mbus = inode->i_private;
sp->slen = snprintf(sp->str, STAT_BUF_SIZE,
"nreaders %d events %u text_lost %u\n",
diff --git a/drivers/usb/mon/mon_text.c b/drivers/usb/mon/mon_text.c
index f961a77..2fd39b4 100644
--- a/drivers/usb/mon/mon_text.c
+++ b/drivers/usb/mon/mon_text.c
@@ -238,7 +238,7 @@
int rc;
mutex_lock(&mon_lock);
- mbus = inode->u.generic_ip;
+ mbus = inode->i_private;
ubus = mbus->u_bus;
rp = kzalloc(sizeof(struct mon_reader_text), GFP_KERNEL);
@@ -401,7 +401,7 @@
struct mon_event_text *ep;
mutex_lock(&mon_lock);
- mbus = inode->u.generic_ip;
+ mbus = inode->i_private;
if (mbus->nreaders <= 0) {
printk(KERN_ERR TAG ": consistency error on close\n");