static int ncp_symlink_readpage(struct file *file, struct page *page)
{
struct inode *inode = page->mapping->host;
int error, length, len;
char *link, *rawlink;
char *buf = kmap(page);
error = -ENOMEM;
rawlink = kmalloc(NCP_MAX_SYMLINK_SIZE, GFP_KERNEL);
if (!rawlink)
goto fail;
if (ncp_make_open(inode,O_RDONLY))
goto failEIO;
error=ncp_read_kernel(NCP_SERVER(inode),NCP_FINFO(inode)->file_handle,
0,NCP_MAX_SYMLINK_SIZE,rawlink,&length);
ncp_inode_close(inode);
/* Close file handle if no other users... */
ncp_make_closed(inode);
if (error)
goto failEIO;
if (NCP_FINFO(inode)->flags & NCPI_KLUDGE_SYMLINK) {
if (length<NCP_MIN_SYMLINK_SIZE ||
((__le32 *)rawlink)[0]!=NCP_SYMLINK_MAGIC0 ||
((__le32 *)rawlink)[1]!=NCP_SYMLINK_MAGIC1)
goto failEIO;
link = rawlink + 8;
length -= 8;
} else {
link = rawlink;
}
len = NCP_MAX_SYMLINK_SIZE;
error = ncp_vol2io(NCP_SERVER(inode), buf, &len, link, length, 0);
kfree(rawlink);
if (error)
goto fail;
SetPageUptodate(page);
kunmap(page);
unlock_page(page);
return 0;
failEIO:
error = -EIO;
kfree(rawlink);
fail:
SetPageError(page);
kunmap(page);
unlock_page(page);
return error;
}
static struct dentry *ncp_follow_link(struct dentry *dentry,
struct dentry *base,
unsigned int follow)
{
struct inode *inode=dentry->d_inode;
int error, length, cnt;
char *link;
#ifdef DEBUG
printk("ncp_follow_link(dentry=%p,base=%p,follow=%u)\n",dentry,base,follow);
#endif
if(!S_ISLNK(inode->i_mode)) {
dput(base);
return ERR_PTR(-EINVAL);
}
if(ncp_make_open(inode,O_RDONLY)) {
dput(base);
return ERR_PTR(-EIO);
}
for (cnt = 0; (link=(char *)kmalloc(NCP_MAX_SYMLINK_SIZE+1, GFP_NFS))==NULL; cnt++) {
if (cnt > 10) {
dput(base);
return ERR_PTR(-EAGAIN); /* -ENOMEM? */
}
schedule();
}
error=ncp_read_kernel(NCP_SERVER(inode),NCP_FINFO(inode)->file_handle,
0,NCP_MAX_SYMLINK_SIZE,link,&length);
if (error!=0 || length<NCP_MIN_SYMLINK_SIZE ||
((__u32 *)link)[0]!=NCP_SYMLINK_MAGIC0 || ((__u32 *)link)[1]!=NCP_SYMLINK_MAGIC1) {
dput(base);
kfree(link);
return ERR_PTR(-EIO);
}
link[length]=0;
vol2io(NCP_SERVER(inode), link+8, 0);
/* UPDATE_ATIME(inode); */
base=lookup_dentry(link+8, base, follow);
kfree(link);
return base;
}
static int ncp_readlink(struct dentry * dentry, char * buffer, int buflen)
{
struct inode *inode=dentry->d_inode;
char *link;
int length,error;
#ifdef DEBUG
printk("ncp_readlink(dentry=%p,buffer=%p,buflen=%d)\n",dentry,buffer,buflen);
#endif
if(!S_ISLNK(inode->i_mode))
return -EINVAL;
if(ncp_make_open(inode,O_RDONLY))
return -EIO;
if((link=(char *)kmalloc(NCP_MAX_SYMLINK_SIZE+1,GFP_NFS))==NULL)
return -ENOMEM;
error = ncp_read_kernel(NCP_SERVER(inode),NCP_FINFO(inode)->file_handle,
0,NCP_MAX_SYMLINK_SIZE,link,&length);
if (error!=0 || length < NCP_MIN_SYMLINK_SIZE || buflen < (length-8) ||
((__u32 *)link)[0]!=NCP_SYMLINK_MAGIC0 ||((__u32 *)link)[1]!=NCP_SYMLINK_MAGIC1) {
error = -EIO;
goto out;
}
link[length] = 0;
vol2io(NCP_SERVER(inode), link+8, 0);
error = length - 8;
if(copy_to_user(buffer, link+8, error))
error = -EFAULT;
out:;
kfree(link);
return error;
}
/*
* Fill in the supplied page for mmap
* XXX: how are we excluding truncate/invalidate here? Maybe need to lock
* page?
*/
static int ncp_file_mmap_fault(struct vm_area_struct *area,
struct vm_fault *vmf)
{
struct file *file = area->vm_file;
struct dentry *dentry = file->f_path.dentry;
struct inode *inode = dentry->d_inode;
char *pg_addr;
unsigned int already_read;
unsigned int count;
int bufsize;
int pos; /* XXX: loff_t ? */
/*
* ncpfs has nothing against high pages as long
* as recvmsg and memset works on it
*/
vmf->page = alloc_page(GFP_HIGHUSER);
if (!vmf->page)
return VM_FAULT_OOM;
pg_addr = kmap(vmf->page);
pos = vmf->pgoff << PAGE_SHIFT;
count = PAGE_SIZE;
/* what we can read in one go */
bufsize = NCP_SERVER(inode)->buffer_size;
already_read = 0;
if (ncp_make_open(inode, O_RDONLY) >= 0) {
while (already_read < count) {
int read_this_time;
int to_read;
to_read = bufsize - (pos % bufsize);
to_read = min_t(unsigned int, to_read, count - already_read);
if (ncp_read_kernel(NCP_SERVER(inode),
NCP_FINFO(inode)->file_handle,
pos, to_read,
pg_addr + already_read,
&read_this_time) != 0) {
read_this_time = 0;
}
pos += read_this_time;
already_read += read_this_time;
if (read_this_time < to_read) {
break;
}
}
ncp_inode_close(inode);
}
if (already_read < PAGE_SIZE)
memset(pg_addr + already_read, 0, PAGE_SIZE - already_read);
flush_dcache_page(vmf->page);
kunmap(vmf->page);
/*
* If I understand ncp_read_kernel() properly, the above always
* fetches from the network, here the analogue of disk.
* -- nyc
*/
count_vm_event(PGMAJFAULT);
mem_cgroup_count_vm_event(area->vm_mm, PGMAJFAULT);
return VM_FAULT_MAJOR;
}
