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454e2398be
linux/fs/openpromfs/inode.c
David Howells 454e2398be [PATCH] VFS: Permit filesystem to override root dentry on mount 
Extend the get_sb() filesystem operation to take an extra argument that
permits the VFS to pass in the target vfsmount that defines the mountpoint.

The filesystem is then required to manually set the superblock and root dentry
pointers.  For most filesystems, this should be done with simple_set_mnt()
which will set the superblock pointer and then set the root dentry to the
superblock's s_root (as per the old default behaviour).

The get_sb() op now returns an integer as there's now no need to return the
superblock pointer.

This patch permits a superblock to be implicitly shared amongst several mount
points, such as can be done with NFS to avoid potential inode aliasing.  In
such a case, simple_set_mnt() would not be called, and instead the mnt_root
and mnt_sb would be set directly.

The patch also makes the following changes:

 (*) the get_sb_*() convenience functions in the core kernel now take a vfsmount
     pointer argument and return an integer, so most filesystems have to change
     very little.

 (*) If one of the convenience function is not used, then get_sb() should
     normally call simple_set_mnt() to instantiate the vfsmount. This will
     always return 0, and so can be tail-called from get_sb().

 (*) generic_shutdown_super() now calls shrink_dcache_sb() to clean up the
     dcache upon superblock destruction rather than shrink_dcache_anon().

     This is required because the superblock may now have multiple trees that
     aren't actually bound to s_root, but that still need to be cleaned up. The
     currently called functions assume that the whole tree is rooted at s_root,
     and that anonymous dentries are not the roots of trees which results in
     dentries being left unculled.

     However, with the way NFS superblock sharing are currently set to be
     implemented, these assumptions are violated: the root of the filesystem is
     simply a dummy dentry and inode (the real inode for '/' may well be
     inaccessible), and all the vfsmounts are rooted on anonymous[*] dentries
     with child trees.

     [*] Anonymous until discovered from another tree.

 (*) The documentation has been adjusted, including the additional bit of
     changing ext2_* into foo_* in the documentation.

[akpm@osdl.org: convert ipath_fs, do other stuff]
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Nathan Scott <nathans@sgi.com>
Cc: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 07:42:45 -07:00

1098 lines
25 KiB
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/* $Id: inode.c,v 1.15 2001/11/12 09:43:39 davem Exp $
* openpromfs.c: /proc/openprom handling routines
*
* Copyright (C) 1996-1999 Jakub Jelinek (jakub@redhat.com)
* Copyright (C) 1998 Eddie C. Dost (ecd@skynet.be)
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/fs.h>
#include <linux/openprom_fs.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/smp_lock.h>
#include <asm/openprom.h>
#include <asm/oplib.h>
#include <asm/uaccess.h>
#define ALIASES_NNODES 64
typedef struct {
u16 parent;
u16 next;
u16 child;
u16 first_prop;
u32 node;
} openpromfs_node;
typedef struct {
#define OPP_STRING 0x10
#define OPP_STRINGLIST 0x20
#define OPP_BINARY 0x40
#define OPP_HEXSTRING 0x80
#define OPP_DIRTY 0x01
#define OPP_QUOTED 0x02
#define OPP_NOTQUOTED 0x04
#define OPP_ASCIIZ 0x08
u32 flag;
u32 alloclen;
u32 len;
char *value;
char name[8];
} openprom_property;
static openpromfs_node *nodes;
static int alloced;
static u16 last_node;
static u16 first_prop;
static u16 options = 0xffff;
static u16 aliases = 0xffff;
static int aliases_nodes;
static char *alias_names [ALIASES_NNODES];
#define OPENPROM_ROOT_INO 16
#define OPENPROM_FIRST_INO OPENPROM_ROOT_INO
#define NODE(ino) nodes[ino - OPENPROM_FIRST_INO]
#define NODE2INO(node) (node + OPENPROM_FIRST_INO)
#define NODEP2INO(no) (no + OPENPROM_FIRST_INO + last_node)
static int openpromfs_create (struct inode *, struct dentry *, int, struct nameidata *);
static int openpromfs_readdir(struct file *, void *, filldir_t);
static struct dentry *openpromfs_lookup(struct inode *, struct dentry *dentry, struct nameidata *nd);
static int openpromfs_unlink (struct inode *, struct dentry *dentry);
static ssize_t nodenum_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
struct inode *inode = file->f_dentry->d_inode;
char buffer[10];
if (count < 0 || !inode->u.generic_ip)
return -EINVAL;
sprintf (buffer, "%8.8x\n", (u32)(long)(inode->u.generic_ip));
if (file->f_pos >= 9)
return 0;
if (count > 9 - file->f_pos)
count = 9 - file->f_pos;
if (copy_to_user(buf, buffer + file->f_pos, count))
return -EFAULT;
*ppos += count;
return count;
}
static ssize_t property_read(struct file *filp, char __user *buf,
size_t count, loff_t *ppos)
{
struct inode *inode = filp->f_dentry->d_inode;
int i, j, k;
u32 node;
char *p, *s;
u32 *q;
openprom_property *op;
char buffer[64];
if (!filp->private_data) {
node = nodes[(u16)((long)inode->u.generic_ip)].node;
i = ((u32)(long)inode->u.generic_ip) >> 16;
if ((u16)((long)inode->u.generic_ip) == aliases) {
if (i >= aliases_nodes)
p = NULL;
else
p = alias_names [i];
} else
for (p = prom_firstprop (node, buffer);
i && p && *p;
p = prom_nextprop (node, p, buffer), i--)
/* nothing */ ;
if (!p || !*p)
return -EIO;
i = prom_getproplen (node, p);
if (i < 0) {
if ((u16)((long)inode->u.generic_ip) == aliases)
i = 0;
else
return -EIO;
}
k = i;
if (i < 64) i = 64;
filp->private_data = kmalloc (sizeof (openprom_property)
+ (j = strlen (p)) + 2 * i,
GFP_KERNEL);
if (!filp->private_data)
return -ENOMEM;
op = (openprom_property *)filp->private_data;
op->flag = 0;
op->alloclen = 2 * i;
strcpy (op->name, p);
op->value = (char *)(((unsigned long)(op->name + j + 4)) & ~3);
op->len = k;
if (k && prom_getproperty (node, p, op->value, i) < 0)
return -EIO;
op->value [k] = 0;
if (k) {
for (s = NULL, p = op->value; p < op->value + k; p++) {
if ((*p >= ' ' && *p <= '~') || *p == '\n') {
op->flag |= OPP_STRING;
s = p;
continue;
}
if (p > op->value && !*p && s == p - 1) {
if (p < op->value + k - 1)
op->flag |= OPP_STRINGLIST;
else
op->flag |= OPP_ASCIIZ;
continue;
}
if (k == 1 && !*p) {
op->flag |= (OPP_STRING|OPP_ASCIIZ);
break;
}
op->flag &= ~(OPP_STRING|OPP_STRINGLIST);
if (k & 3)
op->flag |= OPP_HEXSTRING;
else
op->flag |= OPP_BINARY;
break;
}
if (op->flag & OPP_STRINGLIST)
op->flag &= ~(OPP_STRING);
if (op->flag & OPP_ASCIIZ)
op->len--;
}
} else
op = (openprom_property *)filp->private_data;
if (!count || !(op->len || (op->flag & OPP_ASCIIZ)))
return 0;
if (*ppos >= 0xffffff || count >= 0xffffff)
return -EINVAL;
if (op->flag & OPP_STRINGLIST) {
for (k = 0, p = op->value; p < op->value + op->len; p++)
if (!*p)
k++;
i = op->len + 4 * k + 3;
} else if (op->flag & OPP_STRING) {
i = op->len + 3;
} else if (op->flag & OPP_BINARY) {
i = (op->len * 9) >> 2;
} else {
i = (op->len << 1) + 1;
}
k = *ppos;
if (k >= i) return 0;
if (count > i - k) count = i - k;
if (op->flag & OPP_STRING) {
if (!k) {
if (put_user('\'', buf))
return -EFAULT;
k++;
count--;
}
if (k + count >= i - 2)
j = i - 2 - k;
else
j = count;
if (j >= 0) {
if (copy_to_user(buf + k - *ppos,
op->value + k - 1, j))
return -EFAULT;
count -= j;
k += j;
}
if (count) {
if (put_user('\'', &buf [k++ - *ppos]))
return -EFAULT;
}
if (count > 1) {
if (put_user('\n', &buf [k++ - *ppos]))
return -EFAULT;
}
} else if (op->flag & OPP_STRINGLIST) {
char *tmp;
tmp = kmalloc (i, GFP_KERNEL);
if (!tmp)
return -ENOMEM;
s = tmp;
*s++ = '\'';
for (p = op->value; p < op->value + op->len; p++) {
if (!*p) {
strcpy(s, "' + '");
s += 5;
continue;
}
*s++ = *p;
}
strcpy(s, "'\n");
if (copy_to_user(buf, tmp + k, count))
return -EFAULT;
kfree(tmp);
k += count;
} else if (op->flag & OPP_BINARY) {
char buffer[10];
u32 *first, *last;
int first_off, last_cnt;
first = ((u32 *)op->value) + k / 9;
first_off = k % 9;
last = ((u32 *)op->value) + (k + count - 1) / 9;
last_cnt = (k + count) % 9;
if (!last_cnt) last_cnt = 9;
if (first == last) {
sprintf (buffer, "%08x.", *first);
if (copy_to_user(buf, buffer + first_off,
last_cnt - first_off))
return -EFAULT;
buf += last_cnt - first_off;
} else {
for (q = first; q <= last; q++) {
sprintf (buffer, "%08x.", *q);
if (q == first) {
if (copy_to_user(buf, buffer + first_off,
9 - first_off))
return -EFAULT;
buf += 9 - first_off;
} else if (q == last) {
if (copy_to_user(buf, buffer, last_cnt))
return -EFAULT;
buf += last_cnt;
} else {
if (copy_to_user(buf, buffer, 9))
return -EFAULT;
buf += 9;
}
}
}
if (last == (u32 *)(op->value + op->len - 4) && last_cnt == 9) {
if (put_user('\n', (buf - 1)))
return -EFAULT;
}
k += count;
} else if (op->flag & OPP_HEXSTRING) {
char buffer[3];
if ((k < i - 1) && (k & 1)) {
sprintf (buffer, "%02x",
(unsigned char) *(op->value + (k >> 1)) & 0xff);
if (put_user(buffer[1], &buf[k++ - *ppos]))
return -EFAULT;
count--;
}
for (; (count > 1) && (k < i - 1); k += 2) {
sprintf (buffer, "%02x",
(unsigned char) *(op->value + (k >> 1)) & 0xff);
if (copy_to_user(buf + k - *ppos, buffer, 2))
return -EFAULT;
count -= 2;
}
if (count && (k < i - 1)) {
sprintf (buffer, "%02x",
(unsigned char) *(op->value + (k >> 1)) & 0xff);
if (put_user(buffer[0], &buf[k++ - *ppos]))
return -EFAULT;
count--;
}
if (count) {
if (put_user('\n', &buf [k++ - *ppos]))
return -EFAULT;
}
}
count = k - *ppos;
*ppos = k;
return count;
}
static ssize_t property_write(struct file *filp, const char __user *buf,
size_t count, loff_t *ppos)
{
int i, j, k;
char *p;
u32 *q;
void *b;
openprom_property *op;
if (*ppos >= 0xffffff || count >= 0xffffff)
return -EINVAL;
if (!filp->private_data) {
i = property_read (filp, NULL, 0, NULL);
if (i)
return i;
}
k = *ppos;
op = (openprom_property *)filp->private_data;
if (!(op->flag & OPP_STRING)) {
u32 *first, *last;
int first_off, last_cnt;
u32 mask, mask2;
char tmp [9];
int forcelen = 0;
j = k % 9;
for (i = 0; i < count; i++, j++) {
if (j == 9) j = 0;
if (!j) {
char ctmp;
if (get_user(ctmp, &buf[i]))
return -EFAULT;
if (ctmp != '.') {
if (ctmp != '\n') {
if (op->flag & OPP_BINARY)
return -EINVAL;
else
goto write_try_string;
} else {
count = i + 1;
forcelen = 1;
break;
}
}
} else {
char ctmp;
if (get_user(ctmp, &buf[i]))
return -EFAULT;
if (ctmp < '0' ||
(ctmp > '9' && ctmp < 'A') ||
(ctmp > 'F' && ctmp < 'a') ||
ctmp > 'f') {
if (op->flag & OPP_BINARY)
return -EINVAL;
else
goto write_try_string;
}
}
}
op->flag |= OPP_BINARY;
tmp [8] = 0;
i = ((count + k + 8) / 9) << 2;
if (op->alloclen <= i) {
b = kmalloc (sizeof (openprom_property) + 2 * i,
GFP_KERNEL);
if (!b)
return -ENOMEM;
memcpy (b, filp->private_data,
sizeof (openprom_property)
+ strlen (op->name) + op->alloclen);
memset (((char *)b) + sizeof (openprom_property)
+ strlen (op->name) + op->alloclen,
0, 2 * i - op->alloclen);
op = (openprom_property *)b;
op->alloclen = 2*i;
b = filp->private_data;
filp->private_data = (void *)op;
kfree (b);
}
first = ((u32 *)op->value) + (k / 9);
first_off = k % 9;
last = (u32 *)(op->value + i);
last_cnt = (k + count) % 9;
if (first + 1 == last) {
memset (tmp, '0', 8);
if (copy_from_user(tmp + first_off, buf,
(count + first_off > 8) ?
8 - first_off : count))
return -EFAULT;
mask = 0xffffffff;
mask2 = 0xffffffff;
for (j = 0; j < first_off; j++)
mask >>= 1;
for (j = 8 - count - first_off; j > 0; j--)
mask2 <<= 1;
mask &= mask2;
if (mask) {
*first &= ~mask;
*first |= simple_strtoul (tmp, NULL, 16);
op->flag |= OPP_DIRTY;
}
} else {
op->flag |= OPP_DIRTY;
for (q = first; q < last; q++) {
if (q == first) {
if (first_off < 8) {
memset (tmp, '0', 8);
if (copy_from_user(tmp + first_off,
buf,
8 - first_off))
return -EFAULT;
mask = 0xffffffff;
for (j = 0; j < first_off; j++)
mask >>= 1;
*q &= ~mask;
*q |= simple_strtoul (tmp,NULL,16);
}
buf += 9;
} else if ((q == last - 1) && last_cnt
&& (last_cnt < 8)) {
memset (tmp, '0', 8);
if (copy_from_user(tmp, buf, last_cnt))
return -EFAULT;
mask = 0xffffffff;
for (j = 0; j < 8 - last_cnt; j++)
mask <<= 1;
*q &= ~mask;
*q |= simple_strtoul (tmp, NULL, 16);
buf += last_cnt;
} else {
char tchars[17]; /* XXX yuck... */
if (copy_from_user(tchars, buf, 16))
return -EFAULT;
*q = simple_strtoul (tchars, NULL, 16);
buf += 9;
}
}
}
if (!forcelen) {
if (op->len < i)
op->len = i;
} else
op->len = i;
*ppos += count;
}
write_try_string:
if (!(op->flag & OPP_BINARY)) {
if (!(op->flag & (OPP_QUOTED | OPP_NOTQUOTED))) {
char ctmp;
/* No way, if somebody starts writing from the middle,
* we don't know whether he uses quotes around or not
*/
if (k > 0)
return -EINVAL;
if (get_user(ctmp, buf))
return -EFAULT;
if (ctmp == '\'') {
op->flag |= OPP_QUOTED;
buf++;
count--;
(*ppos)++;
if (!count) {
op->flag |= OPP_STRING;
return 1;
}
} else
op->flag |= OPP_NOTQUOTED;
}
op->flag |= OPP_STRING;
if (op->alloclen <= count + *ppos) {
b = kmalloc (sizeof (openprom_property)
+ 2 * (count + *ppos), GFP_KERNEL);
if (!b)
return -ENOMEM;
memcpy (b, filp->private_data,
sizeof (openprom_property)
+ strlen (op->name) + op->alloclen);
memset (((char *)b) + sizeof (openprom_property)
+ strlen (op->name) + op->alloclen,
0, 2*(count - *ppos) - op->alloclen);
op = (openprom_property *)b;
op->alloclen = 2*(count + *ppos);
b = filp->private_data;
filp->private_data = (void *)op;
kfree (b);
}
p = op->value + *ppos - ((op->flag & OPP_QUOTED) ? 1 : 0);
if (copy_from_user(p, buf, count))
return -EFAULT;
op->flag |= OPP_DIRTY;
for (i = 0; i < count; i++, p++)
if (*p == '\n') {
*p = 0;
break;
}
if (i < count) {
op->len = p - op->value;
*ppos += i + 1;
if ((p > op->value) && (op->flag & OPP_QUOTED)
&& (*(p - 1) == '\''))
op->len--;
} else {
if (p - op->value > op->len)
op->len = p - op->value;
*ppos += count;
}
}
return *ppos - k;
}
int property_release (struct inode *inode, struct file *filp)
{
openprom_property *op = (openprom_property *)filp->private_data;
int error;
u32 node;
if (!op)
return 0;
lock_kernel();
node = nodes[(u16)((long)inode->u.generic_ip)].node;
if ((u16)((long)inode->u.generic_ip) == aliases) {
if ((op->flag & OPP_DIRTY) && (op->flag & OPP_STRING)) {
char *p = op->name;
int i = (op->value - op->name) - strlen (op->name) - 1;
op->value [op->len] = 0;
*(op->value - 1) = ' ';
if (i) {
for (p = op->value - i - 2; p >= op->name; p--)
p[i] = *p;
p = op->name + i;
}
memcpy (p - 8, "nvalias ", 8);
prom_feval (p - 8);
}
} else if (op->flag & OPP_DIRTY) {
if (op->flag & OPP_STRING) {
op->value [op->len] = 0;
error = prom_setprop (node, op->name,
op->value, op->len + 1);
if (error <= 0)
printk (KERN_WARNING "openpromfs: "
"Couldn't write property %s\n",
op->name);
} else if ((op->flag & OPP_BINARY) || !op->len) {
error = prom_setprop (node, op->name,
op->value, op->len);
if (error <= 0)
printk (KERN_WARNING "openpromfs: "
"Couldn't write property %s\n",
op->name);
} else {
printk (KERN_WARNING "openpromfs: "
"Unknown property type of %s\n",
op->name);
}
}
unlock_kernel();
kfree (filp->private_data);
return 0;
}
static const struct file_operations openpromfs_prop_ops = {
.read = property_read,
.write = property_write,
.release = property_release,
};
static const struct file_operations openpromfs_nodenum_ops = {
.read = nodenum_read,
};
static const struct file_operations openprom_operations = {
.read = generic_read_dir,
.readdir = openpromfs_readdir,
};
static struct inode_operations openprom_alias_inode_operations = {
.create = openpromfs_create,
.lookup = openpromfs_lookup,
.unlink = openpromfs_unlink,
};
static struct inode_operations openprom_inode_operations = {
.lookup = openpromfs_lookup,
};
static int lookup_children(u16 n, const char * name, int len)
{
int ret;
u16 node;
for (; n != 0xffff; n = nodes[n].next) {
node = nodes[n].child;
if (node != 0xffff) {
char buffer[128];
int i;
char *p;
while (node != 0xffff) {
if (prom_getname (nodes[node].node,
buffer, 128) >= 0) {
i = strlen (buffer);
if ((len == i)
&& !strncmp (buffer, name, len))
return NODE2INO(node);
p = strchr (buffer, '@');
if (p && (len == p - buffer)
&& !strncmp (buffer, name, len))
return NODE2INO(node);
}
node = nodes[node].next;
}
} else
continue;
ret = lookup_children (nodes[n].child, name, len);
if (ret) return ret;
}
return 0;
}
static struct dentry *openpromfs_lookup(struct inode * dir, struct dentry *dentry, struct nameidata *nd)
{
int ino = 0;
#define OPFSL_DIR 0
#define OPFSL_PROPERTY 1
#define OPFSL_NODENUM 2
int type = 0;
char buffer[128];
char *p;
const char *name;
u32 n;
u16 dirnode;
unsigned int len;
int i;
struct inode *inode;
char buffer2[64];
inode = NULL;
name = dentry->d_name.name;
len = dentry->d_name.len;
lock_kernel();
if (name [0] == '.' && len == 5 && !strncmp (name + 1, "node", 4)) {
ino = NODEP2INO(NODE(dir->i_ino).first_prop);
type = OPFSL_NODENUM;
}
if (!ino) {
u16 node = NODE(dir->i_ino).child;
while (node != 0xffff) {
if (prom_getname (nodes[node].node, buffer, 128) >= 0) {
i = strlen (buffer);
if (len == i && !strncmp (buffer, name, len)) {
ino = NODE2INO(node);
type = OPFSL_DIR;
break;
}
p = strchr (buffer, '@');
if (p && (len == p - buffer)
&& !strncmp (buffer, name, len)) {
ino = NODE2INO(node);
type = OPFSL_DIR;
break;
}
}
node = nodes[node].next;
}
}
n = NODE(dir->i_ino).node;
dirnode = dir->i_ino - OPENPROM_FIRST_INO;
if (!ino) {
int j = NODEP2INO(NODE(dir->i_ino).first_prop);
if (dirnode != aliases) {
for (p = prom_firstprop (n, buffer2);
p && *p;
p = prom_nextprop (n, p, buffer2)) {
j++;
if ((len == strlen (p))
&& !strncmp (p, name, len)) {
ino = j;
type = OPFSL_PROPERTY;
break;
}
}
} else {
int k;
for (k = 0; k < aliases_nodes; k++) {
j++;
if (alias_names [k]
&& (len == strlen (alias_names [k]))
&& !strncmp (alias_names [k], name, len)) {
ino = j;
type = OPFSL_PROPERTY;
break;
}
}
}
}
if (!ino) {
ino = lookup_children (NODE(dir->i_ino).child, name, len);
if (ino)
type = OPFSL_DIR;
else {
unlock_kernel();
return ERR_PTR(-ENOENT);
}
}
inode = iget (dir->i_sb, ino);
unlock_kernel();
if (!inode)
return ERR_PTR(-EINVAL);
switch (type) {
case OPFSL_DIR:
inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO;
if (ino == OPENPROM_FIRST_INO + aliases) {
inode->i_mode |= S_IWUSR;
inode->i_op = &openprom_alias_inode_operations;
} else
inode->i_op = &openprom_inode_operations;
inode->i_fop = &openprom_operations;
inode->i_nlink = 2;
break;
case OPFSL_NODENUM:
inode->i_mode = S_IFREG | S_IRUGO;
inode->i_fop = &openpromfs_nodenum_ops;
inode->i_nlink = 1;
inode->u.generic_ip = (void *)(long)(n);
break;
case OPFSL_PROPERTY:
if ((dirnode == options) && (len == 17)
&& !strncmp (name, "security-password", 17))
inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR;
else {
inode->i_mode = S_IFREG | S_IRUGO;
if (dirnode == options || dirnode == aliases) {
if (len != 4 || strncmp (name, "name", 4))
inode->i_mode |= S_IWUSR;
}
}
inode->i_fop = &openpromfs_prop_ops;
inode->i_nlink = 1;
if (inode->i_size < 0)
inode->i_size = 0;
inode->u.generic_ip = (void *)(long)(((u16)dirnode) |
(((u16)(ino - NODEP2INO(NODE(dir->i_ino).first_prop) - 1)) << 16));
break;
}
inode->i_gid = 0;
inode->i_uid = 0;
d_add(dentry, inode);
return NULL;
}
static int openpromfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
{
struct inode *inode = filp->f_dentry->d_inode;
unsigned int ino;
u32 n;
int i, j;
char buffer[128];
u16 node;
char *p;
char buffer2[64];
lock_kernel();
ino = inode->i_ino;
i = filp->f_pos;
switch (i) {
case 0:
if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) goto out;
i++;
filp->f_pos++;
/* fall thru */
case 1:
if (filldir(dirent, "..", 2, i,
(NODE(ino).parent == 0xffff) ?
OPENPROM_ROOT_INO : NODE2INO(NODE(ino).parent), DT_DIR) < 0)
goto out;
i++;
filp->f_pos++;
/* fall thru */
default:
i -= 2;
node = NODE(ino).child;
while (i && node != 0xffff) {
node = nodes[node].next;
i--;
}
while (node != 0xffff) {
if (prom_getname (nodes[node].node, buffer, 128) < 0)
goto out;
if (filldir(dirent, buffer, strlen(buffer),
filp->f_pos, NODE2INO(node), DT_DIR) < 0)
goto out;
filp->f_pos++;
node = nodes[node].next;
}
j = NODEP2INO(NODE(ino).first_prop);
if (!i) {
if (filldir(dirent, ".node", 5, filp->f_pos, j, DT_REG) < 0)
goto out;
filp->f_pos++;
} else
i--;
n = NODE(ino).node;
if (ino == OPENPROM_FIRST_INO + aliases) {
for (j++; i < aliases_nodes; i++, j++) {
if (alias_names [i]) {
if (filldir (dirent, alias_names [i],
strlen (alias_names [i]),
filp->f_pos, j, DT_REG) < 0) goto out;
filp->f_pos++;
}
}
} else {
for (p = prom_firstprop (n, buffer2);
p && *p;
p = prom_nextprop (n, p, buffer2)) {
j++;
if (i) i--;
else {
if (filldir(dirent, p, strlen(p),
filp->f_pos, j, DT_REG) < 0)
goto out;
filp->f_pos++;
}
}
}
}
out:
unlock_kernel();
return 0;
}
static int openpromfs_create (struct inode *dir, struct dentry *dentry, int mode,
struct nameidata *nd)
{
char *p;
struct inode *inode;
if (!dir)
return -ENOENT;
if (dentry->d_name.len > 256)
return -EINVAL;
p = kmalloc (dentry->d_name.len + 1, GFP_KERNEL);
if (!p)
return -ENOMEM;
strncpy (p, dentry->d_name.name, dentry->d_name.len);
p [dentry->d_name.len] = 0;
lock_kernel();
if (aliases_nodes == ALIASES_NNODES) {
kfree(p);
unlock_kernel();
return -EIO;
}
alias_names [aliases_nodes++] = p;
inode = iget (dir->i_sb,
NODEP2INO(NODE(dir->i_ino).first_prop) + aliases_nodes);
if (!inode) {
unlock_kernel();
return -EINVAL;
}
inode->i_mode = S_IFREG | S_IRUGO | S_IWUSR;
inode->i_fop = &openpromfs_prop_ops;
inode->i_nlink = 1;
if (inode->i_size < 0) inode->i_size = 0;
inode->u.generic_ip = (void *)(long)(((u16)aliases) |
(((u16)(aliases_nodes - 1)) << 16));
unlock_kernel();
d_instantiate(dentry, inode);
return 0;
}
static int openpromfs_unlink (struct inode *dir, struct dentry *dentry)
{
unsigned int len;
char *p;
const char *name;
int i;
name = dentry->d_name.name;
len = dentry->d_name.len;
lock_kernel();
for (i = 0; i < aliases_nodes; i++)
if ((strlen (alias_names [i]) == len)
&& !strncmp (name, alias_names[i], len)) {
char buffer[512];
p = alias_names [i];
alias_names [i] = NULL;
kfree (p);
strcpy (buffer, "nvunalias ");
memcpy (buffer + 10, name, len);
buffer [10 + len] = 0;
prom_feval (buffer);
}
unlock_kernel();
return 0;
}
/* {{{ init section */
static int __init check_space (u16 n)
{
unsigned long pages;
if ((1 << alloced) * PAGE_SIZE < (n + 2) * sizeof(openpromfs_node)) {
pages = __get_free_pages (GFP_KERNEL, alloced + 1);
if (!pages)
return -1;
if (nodes) {
memcpy ((char *)pages, (char *)nodes,
(1 << alloced) * PAGE_SIZE);
free_pages ((unsigned long)nodes, alloced);
}
alloced++;
nodes = (openpromfs_node *)pages;
}
return 0;
}
static u16 __init get_nodes (u16 parent, u32 node)
{
char *p;
u16 n = last_node++, i;
char buffer[64];
if (check_space (n) < 0)
return 0xffff;
nodes[n].parent = parent;
nodes[n].node = node;
nodes[n].next = 0xffff;
nodes[n].child = 0xffff;
nodes[n].first_prop = first_prop++;
if (!parent) {
char buffer[8];
int j;
if ((j = prom_getproperty (node, "name", buffer, 8)) >= 0) {
buffer[j] = 0;
if (!strcmp (buffer, "options"))
options = n;
else if (!strcmp (buffer, "aliases"))
aliases = n;
}
}
if (n != aliases)
for (p = prom_firstprop (node, buffer);
p && p != (char *)-1 && *p;
p = prom_nextprop (node, p, buffer))
first_prop++;
else {
char *q;
for (p = prom_firstprop (node, buffer);
p && p != (char *)-1 && *p;
p = prom_nextprop (node, p, buffer)) {
if (aliases_nodes == ALIASES_NNODES)
break;
for (i = 0; i < aliases_nodes; i++)
if (!strcmp (p, alias_names [i]))
break;
if (i < aliases_nodes)
continue;
q = kmalloc (strlen (p) + 1, GFP_KERNEL);
if (!q)
return 0xffff;
strcpy (q, p);
alias_names [aliases_nodes++] = q;
}
first_prop += ALIASES_NNODES;
}
node = prom_getchild (node);
if (node) {
parent = get_nodes (n, node);
if (parent == 0xffff)
return 0xffff;
nodes[n].child = parent;
while ((node = prom_getsibling (node)) != 0) {
i = get_nodes (n, node);
if (i == 0xffff)
return 0xffff;
nodes[parent].next = i;
parent = i;
}
}
return n;
}
static void openprom_read_inode(struct inode * inode)
{
inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
if (inode->i_ino == OPENPROM_ROOT_INO) {
inode->i_op = &openprom_inode_operations;
inode->i_fop = &openprom_operations;
inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO;
}
}
static int openprom_remount(struct super_block *sb, int *flags, char *data)
{
*flags |= MS_NOATIME;
return 0;
}
static struct super_operations openprom_sops = {
.read_inode = openprom_read_inode,
.statfs = simple_statfs,
.remount_fs = openprom_remount,
};
static int openprom_fill_super(struct super_block *s, void *data, int silent)
{
struct inode * root_inode;
s->s_flags |= MS_NOATIME;
s->s_blocksize = 1024;
s->s_blocksize_bits = 10;
s->s_magic = OPENPROM_SUPER_MAGIC;
s->s_op = &openprom_sops;
s->s_time_gran = 1;
root_inode = iget(s, OPENPROM_ROOT_INO);
if (!root_inode)
goto out_no_root;
s->s_root = d_alloc_root(root_inode);
if (!s->s_root)
goto out_no_root;
return 0;
out_no_root:
printk("openprom_fill_super: get root inode failed\n");
iput(root_inode);
return -ENOMEM;
}
static int openprom_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data, struct vfsmount *mnt)
{
return get_sb_single(fs_type, flags, data, openprom_fill_super, mnt);
}
static struct file_system_type openprom_fs_type = {
.owner = THIS_MODULE,
.name = "openpromfs",
.get_sb = openprom_get_sb,
.kill_sb = kill_anon_super,
};
static int __init init_openprom_fs(void)
{
nodes = (openpromfs_node *)__get_free_pages(GFP_KERNEL, 0);
if (!nodes) {
printk (KERN_WARNING "openpromfs: can't get free page\n");
return -EIO;
}
if (get_nodes (0xffff, prom_root_node) == 0xffff) {
printk (KERN_WARNING "openpromfs: couldn't setup tree\n");
return -EIO;
}
nodes[last_node].first_prop = first_prop;
return register_filesystem(&openprom_fs_type);
}
static void __exit exit_openprom_fs(void)
{
int i;
unregister_filesystem(&openprom_fs_type);
free_pages ((unsigned long)nodes, alloced);
for (i = 0; i < aliases_nodes; i++)
kfree (alias_names [i]);
nodes = NULL;
}
module_init(init_openprom_fs)
module_exit(exit_openprom_fs)
MODULE_LICENSE("GPL");
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