![Randy Dunlap](/assets/img/avatar_default.png)
Remove includes of <linux/smp_lock.h> where it is not used/needed. Suggested by Al Viro. Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc, sparc64, and arm (all 59 defconfigs). Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
295 lines
7.6 KiB
C
295 lines
7.6 KiB
C
/* file-nommu.c: no-MMU version of ramfs
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*
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* Copyright (C) 2005 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/module.h>
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#include <linux/fs.h>
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#include <linux/mm.h>
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#include <linux/pagemap.h>
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#include <linux/highmem.h>
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#include <linux/init.h>
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#include <linux/string.h>
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#include <linux/backing-dev.h>
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#include <linux/ramfs.h>
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#include <linux/quotaops.h>
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#include <linux/pagevec.h>
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#include <linux/mman.h>
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#include <asm/uaccess.h>
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#include "internal.h"
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static int ramfs_nommu_setattr(struct dentry *, struct iattr *);
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const struct address_space_operations ramfs_aops = {
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.readpage = simple_readpage,
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.prepare_write = simple_prepare_write,
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.commit_write = simple_commit_write,
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.set_page_dirty = __set_page_dirty_no_writeback,
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};
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const struct file_operations ramfs_file_operations = {
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.mmap = ramfs_nommu_mmap,
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.get_unmapped_area = ramfs_nommu_get_unmapped_area,
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.read = do_sync_read,
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.aio_read = generic_file_aio_read,
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.write = do_sync_write,
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.aio_write = generic_file_aio_write,
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.fsync = simple_sync_file,
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.sendfile = generic_file_sendfile,
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.llseek = generic_file_llseek,
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};
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const struct inode_operations ramfs_file_inode_operations = {
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.setattr = ramfs_nommu_setattr,
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.getattr = simple_getattr,
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};
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/*****************************************************************************/
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/*
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* add a contiguous set of pages into a ramfs inode when it's truncated from
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* size 0 on the assumption that it's going to be used for an mmap of shared
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* memory
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*/
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static int ramfs_nommu_expand_for_mapping(struct inode *inode, size_t newsize)
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{
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struct pagevec lru_pvec;
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unsigned long npages, xpages, loop, limit;
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struct page *pages;
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unsigned order;
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void *data;
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int ret;
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/* make various checks */
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order = get_order(newsize);
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if (unlikely(order >= MAX_ORDER))
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goto too_big;
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limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
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if (limit != RLIM_INFINITY && newsize > limit)
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goto fsize_exceeded;
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if (newsize > inode->i_sb->s_maxbytes)
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goto too_big;
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i_size_write(inode, newsize);
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/* allocate enough contiguous pages to be able to satisfy the
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* request */
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pages = alloc_pages(mapping_gfp_mask(inode->i_mapping), order);
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if (!pages)
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return -ENOMEM;
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/* split the high-order page into an array of single pages */
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xpages = 1UL << order;
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npages = (newsize + PAGE_SIZE - 1) >> PAGE_SHIFT;
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split_page(pages, order);
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/* trim off any pages we don't actually require */
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for (loop = npages; loop < xpages; loop++)
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__free_page(pages + loop);
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/* clear the memory we allocated */
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newsize = PAGE_SIZE * npages;
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data = page_address(pages);
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memset(data, 0, newsize);
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/* attach all the pages to the inode's address space */
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pagevec_init(&lru_pvec, 0);
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for (loop = 0; loop < npages; loop++) {
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struct page *page = pages + loop;
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ret = add_to_page_cache(page, inode->i_mapping, loop, GFP_KERNEL);
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if (ret < 0)
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goto add_error;
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if (!pagevec_add(&lru_pvec, page))
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__pagevec_lru_add(&lru_pvec);
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unlock_page(page);
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}
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pagevec_lru_add(&lru_pvec);
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return 0;
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fsize_exceeded:
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send_sig(SIGXFSZ, current, 0);
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too_big:
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return -EFBIG;
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add_error:
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page_cache_release(pages + loop);
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for (loop++; loop < npages; loop++)
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__free_page(pages + loop);
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return ret;
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}
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/*****************************************************************************/
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/*
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* check that file shrinkage doesn't leave any VMAs dangling in midair
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*/
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static int ramfs_nommu_check_mappings(struct inode *inode,
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size_t newsize, size_t size)
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{
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struct vm_area_struct *vma;
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struct prio_tree_iter iter;
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/* search for VMAs that fall within the dead zone */
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vma_prio_tree_foreach(vma, &iter, &inode->i_mapping->i_mmap,
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newsize >> PAGE_SHIFT,
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(size + PAGE_SIZE - 1) >> PAGE_SHIFT
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) {
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/* found one - only interested if it's shared out of the page
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* cache */
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if (vma->vm_flags & VM_SHARED)
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return -ETXTBSY; /* not quite true, but near enough */
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}
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return 0;
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}
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/*****************************************************************************/
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/*
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*
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*/
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static int ramfs_nommu_resize(struct inode *inode, loff_t newsize, loff_t size)
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{
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int ret;
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/* assume a truncate from zero size is going to be for the purposes of
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* shared mmap */
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if (size == 0) {
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if (unlikely(newsize >> 32))
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return -EFBIG;
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return ramfs_nommu_expand_for_mapping(inode, newsize);
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}
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/* check that a decrease in size doesn't cut off any shared mappings */
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if (newsize < size) {
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ret = ramfs_nommu_check_mappings(inode, newsize, size);
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if (ret < 0)
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return ret;
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}
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ret = vmtruncate(inode, size);
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return ret;
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}
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/*****************************************************************************/
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/*
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* handle a change of attributes
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* - we're specifically interested in a change of size
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*/
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static int ramfs_nommu_setattr(struct dentry *dentry, struct iattr *ia)
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{
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struct inode *inode = dentry->d_inode;
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unsigned int old_ia_valid = ia->ia_valid;
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int ret = 0;
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/* by providing our own setattr() method, we skip this quotaism */
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if ((old_ia_valid & ATTR_UID && ia->ia_uid != inode->i_uid) ||
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(old_ia_valid & ATTR_GID && ia->ia_gid != inode->i_gid))
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ret = DQUOT_TRANSFER(inode, ia) ? -EDQUOT : 0;
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/* pick out size-changing events */
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if (ia->ia_valid & ATTR_SIZE) {
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loff_t size = i_size_read(inode);
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if (ia->ia_size != size) {
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ret = ramfs_nommu_resize(inode, ia->ia_size, size);
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if (ret < 0 || ia->ia_valid == ATTR_SIZE)
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goto out;
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} else {
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/* we skipped the truncate but must still update
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* timestamps
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*/
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ia->ia_valid |= ATTR_MTIME|ATTR_CTIME;
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}
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}
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ret = inode_setattr(inode, ia);
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out:
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ia->ia_valid = old_ia_valid;
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return ret;
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}
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/*****************************************************************************/
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/*
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* try to determine where a shared mapping can be made
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* - we require that:
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* - the pages to be mapped must exist
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* - the pages be physically contiguous in sequence
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*/
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unsigned long ramfs_nommu_get_unmapped_area(struct file *file,
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unsigned long addr, unsigned long len,
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unsigned long pgoff, unsigned long flags)
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{
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unsigned long maxpages, lpages, nr, loop, ret;
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struct inode *inode = file->f_path.dentry->d_inode;
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struct page **pages = NULL, **ptr, *page;
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loff_t isize;
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if (!(flags & MAP_SHARED))
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return addr;
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/* the mapping mustn't extend beyond the EOF */
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lpages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
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isize = i_size_read(inode);
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ret = -EINVAL;
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maxpages = (isize + PAGE_SIZE - 1) >> PAGE_SHIFT;
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if (pgoff >= maxpages)
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goto out;
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if (maxpages - pgoff < lpages)
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goto out;
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/* gang-find the pages */
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ret = -ENOMEM;
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pages = kzalloc(lpages * sizeof(struct page *), GFP_KERNEL);
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if (!pages)
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goto out;
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nr = find_get_pages(inode->i_mapping, pgoff, lpages, pages);
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if (nr != lpages)
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goto out; /* leave if some pages were missing */
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/* check the pages for physical adjacency */
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ptr = pages;
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page = *ptr++;
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page++;
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for (loop = lpages; loop > 1; loop--)
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if (*ptr++ != page++)
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goto out;
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/* okay - all conditions fulfilled */
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ret = (unsigned long) page_address(pages[0]);
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out:
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if (pages) {
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ptr = pages;
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for (loop = lpages; loop > 0; loop--)
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put_page(*ptr++);
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kfree(pages);
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}
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return ret;
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}
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/*****************************************************************************/
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/*
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* set up a mapping for shared memory segments
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*/
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int ramfs_nommu_mmap(struct file *file, struct vm_area_struct *vma)
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{
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return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
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}
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