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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-17 02:20:36 +0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-17 02:20:36 +0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/ncpfs/mmap.c | |
download | linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'fs/ncpfs/mmap.c')
-rw-r--r-- | fs/ncpfs/mmap.c | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/fs/ncpfs/mmap.c b/fs/ncpfs/mmap.c new file mode 100644 index 000000000000..52d60c3d8996 --- /dev/null +++ b/fs/ncpfs/mmap.c @@ -0,0 +1,128 @@ +/* + * mmap.c + * + * Copyright (C) 1995, 1996 by Volker Lendecke + * Modified 1997 Peter Waltenberg, Bill Hawes, David Woodhouse for 2.1 dcache + * + */ + +#include <linux/stat.h> +#include <linux/time.h> +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/shm.h> +#include <linux/errno.h> +#include <linux/mman.h> +#include <linux/string.h> +#include <linux/slab.h> +#include <linux/fcntl.h> +#include <linux/ncp_fs.h> + +#include "ncplib_kernel.h" +#include <asm/uaccess.h> +#include <asm/system.h> + +/* + * Fill in the supplied page for mmap + */ +static struct page* ncp_file_mmap_nopage(struct vm_area_struct *area, + unsigned long address, int *type) +{ + struct file *file = area->vm_file; + struct dentry *dentry = file->f_dentry; + struct inode *inode = dentry->d_inode; + struct page* page; + char *pg_addr; + unsigned int already_read; + unsigned int count; + int bufsize; + int pos; + + page = alloc_page(GFP_HIGHUSER); /* ncpfs has nothing against high pages + as long as recvmsg and memset works on it */ + if (!page) + return page; + pg_addr = kmap(page); + address &= PAGE_MASK; + pos = address - area->vm_start + (area->vm_pgoff << PAGE_SHIFT); + + count = PAGE_SIZE; + if (address + PAGE_SIZE > area->vm_end) { + count = area->vm_end - address; + } + /* 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(page); + kunmap(page); + + /* + * If I understand ncp_read_kernel() properly, the above always + * fetches from the network, here the analogue of disk. + * -- wli + */ + if (type) + *type = VM_FAULT_MAJOR; + inc_page_state(pgmajfault); + return page; +} + +static struct vm_operations_struct ncp_file_mmap = +{ + .nopage = ncp_file_mmap_nopage, +}; + + +/* This is used for a general mmap of a ncp file */ +int ncp_mmap(struct file *file, struct vm_area_struct *vma) +{ + struct inode *inode = file->f_dentry->d_inode; + + DPRINTK("ncp_mmap: called\n"); + + if (!ncp_conn_valid(NCP_SERVER(inode))) + return -EIO; + + /* only PAGE_COW or read-only supported now */ + if (vma->vm_flags & VM_SHARED) + return -EINVAL; + /* we do not support files bigger than 4GB... We eventually + supports just 4GB... */ + if (((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff + > (1U << (32 - PAGE_SHIFT))) + return -EFBIG; + + vma->vm_ops = &ncp_file_mmap; + file_accessed(file); + return 0; +} |