2005-06-24 05:05:25 +00:00
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/*
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* linux/mm/filemap_xip.c
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*
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* Copyright (C) 2005 IBM Corporation
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* Author: Carsten Otte <cotte@de.ibm.com>
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*
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* derived from linux/mm/filemap.c - Copyright (C) Linus Torvalds
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*
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*/
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#include <linux/fs.h>
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#include <linux/pagemap.h>
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#include <linux/module.h>
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#include <linux/uio.h>
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#include <linux/rmap.h>
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Detach sched.h from mm.h
First thing mm.h does is including sched.h solely for can_do_mlock() inline
function which has "current" dereference inside. By dealing with can_do_mlock()
mm.h can be detached from sched.h which is good. See below, why.
This patch
a) removes unconditional inclusion of sched.h from mm.h
b) makes can_do_mlock() normal function in mm/mlock.c
c) exports can_do_mlock() to not break compilation
d) adds sched.h inclusions back to files that were getting it indirectly.
e) adds less bloated headers to some files (asm/signal.h, jiffies.h) that were
getting them indirectly
Net result is:
a) mm.h users would get less code to open, read, preprocess, parse, ... if
they don't need sched.h
b) sched.h stops being dependency for significant number of files:
on x86_64 allmodconfig touching sched.h results in recompile of 4083 files,
after patch it's only 3744 (-8.3%).
Cross-compile tested on
all arm defconfigs, all mips defconfigs, all powerpc defconfigs,
alpha alpha-up
arm
i386 i386-up i386-defconfig i386-allnoconfig
ia64 ia64-up
m68k
mips
parisc parisc-up
powerpc powerpc-up
s390 s390-up
sparc sparc-up
sparc64 sparc64-up
um-x86_64
x86_64 x86_64-up x86_64-defconfig x86_64-allnoconfig
as well as my two usual configs.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-20 21:22:52 +00:00
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#include <linux/sched.h>
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2005-06-24 05:05:25 +00:00
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#include <asm/tlbflush.h>
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2007-03-29 08:20:39 +00:00
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/*
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* We do use our own empty page to avoid interference with other users
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* of ZERO_PAGE(), such as /dev/zero
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*/
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static struct page *__xip_sparse_page;
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static struct page *xip_sparse_page(void)
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{
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if (!__xip_sparse_page) {
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2008-01-08 23:32:57 +00:00
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struct page *page = alloc_page(GFP_HIGHUSER | __GFP_ZERO);
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if (page) {
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2007-03-29 08:20:39 +00:00
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static DEFINE_SPINLOCK(xip_alloc_lock);
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spin_lock(&xip_alloc_lock);
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if (!__xip_sparse_page)
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2008-01-08 23:32:57 +00:00
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__xip_sparse_page = page;
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2007-03-29 08:20:39 +00:00
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else
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2008-01-08 23:32:57 +00:00
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__free_page(page);
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2007-03-29 08:20:39 +00:00
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spin_unlock(&xip_alloc_lock);
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}
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}
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return __xip_sparse_page;
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}
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2005-06-24 05:05:25 +00:00
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/*
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* This is a file read routine for execute in place files, and uses
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* the mapping->a_ops->get_xip_page() function for the actual low-level
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* stuff.
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*
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* Note the struct file* is not used at all. It may be NULL.
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*/
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static void
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do_xip_mapping_read(struct address_space *mapping,
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struct file_ra_state *_ra,
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struct file *filp,
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loff_t *ppos,
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read_descriptor_t *desc,
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read_actor_t actor)
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{
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struct inode *inode = mapping->host;
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unsigned long index, end_index, offset;
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loff_t isize;
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BUG_ON(!mapping->a_ops->get_xip_page);
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index = *ppos >> PAGE_CACHE_SHIFT;
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offset = *ppos & ~PAGE_CACHE_MASK;
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isize = i_size_read(inode);
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if (!isize)
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goto out;
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end_index = (isize - 1) >> PAGE_CACHE_SHIFT;
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for (;;) {
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struct page *page;
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unsigned long nr, ret;
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/* nr is the maximum number of bytes to copy from this page */
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nr = PAGE_CACHE_SIZE;
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if (index >= end_index) {
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if (index > end_index)
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goto out;
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nr = ((isize - 1) & ~PAGE_CACHE_MASK) + 1;
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if (nr <= offset) {
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goto out;
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}
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}
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nr = nr - offset;
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page = mapping->a_ops->get_xip_page(mapping,
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index*(PAGE_SIZE/512), 0);
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if (!page)
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goto no_xip_page;
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if (unlikely(IS_ERR(page))) {
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if (PTR_ERR(page) == -ENODATA) {
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/* sparse */
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2005-07-15 10:56:30 +00:00
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page = ZERO_PAGE(0);
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2005-06-24 05:05:25 +00:00
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} else {
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desc->error = PTR_ERR(page);
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goto out;
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}
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2005-07-15 10:56:30 +00:00
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}
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2005-06-24 05:05:25 +00:00
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/* If users can be writing to this page using arbitrary
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* virtual addresses, take care about potential aliasing
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* before reading the page on the kernel side.
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*/
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if (mapping_writably_mapped(mapping))
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flush_dcache_page(page);
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/*
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2005-07-15 10:56:30 +00:00
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* Ok, we have the page, so now we can copy it to user space...
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2005-06-24 05:05:25 +00:00
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*
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* The actor routine returns how many bytes were actually used..
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* NOTE! This may not be the same as how much of a user buffer
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* we filled up (we may be padding etc), so we can only update
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* "pos" here (the actor routine has to update the user buffer
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* pointers and the remaining count).
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*/
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ret = actor(desc, page, offset, nr);
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offset += ret;
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index += offset >> PAGE_CACHE_SHIFT;
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offset &= ~PAGE_CACHE_MASK;
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if (ret == nr && desc->count)
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continue;
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goto out;
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no_xip_page:
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/* Did not get the page. Report it */
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desc->error = -EIO;
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goto out;
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}
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out:
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*ppos = ((loff_t) index << PAGE_CACHE_SHIFT) + offset;
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if (filp)
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file_accessed(filp);
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}
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ssize_t
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2005-06-24 05:05:28 +00:00
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xip_file_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos)
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2005-06-24 05:05:25 +00:00
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{
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2005-06-24 05:05:28 +00:00
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read_descriptor_t desc;
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2005-06-24 05:05:25 +00:00
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2005-06-24 05:05:28 +00:00
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if (!access_ok(VERIFY_WRITE, buf, len))
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return -EFAULT;
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2005-06-24 05:05:25 +00:00
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2005-06-24 05:05:28 +00:00
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desc.written = 0;
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desc.arg.buf = buf;
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desc.count = len;
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desc.error = 0;
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2005-06-24 05:05:25 +00:00
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2005-06-24 05:05:28 +00:00
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do_xip_mapping_read(filp->f_mapping, &filp->f_ra, filp,
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ppos, &desc, file_read_actor);
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if (desc.written)
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return desc.written;
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else
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return desc.error;
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2005-06-24 05:05:25 +00:00
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}
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2005-06-24 05:05:28 +00:00
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EXPORT_SYMBOL_GPL(xip_file_read);
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2005-06-24 05:05:25 +00:00
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/*
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* __xip_unmap is invoked from xip_unmap and
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* xip_write
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*
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* This function walks all vmas of the address_space and unmaps the
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2007-03-29 08:20:39 +00:00
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* __xip_sparse_page when found at pgoff.
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2005-06-24 05:05:25 +00:00
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*/
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static void
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__xip_unmap (struct address_space * mapping,
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unsigned long pgoff)
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{
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struct vm_area_struct *vma;
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struct mm_struct *mm;
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struct prio_tree_iter iter;
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unsigned long address;
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pte_t *pte;
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pte_t pteval;
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2005-10-30 01:16:31 +00:00
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spinlock_t *ptl;
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2005-10-30 01:16:31 +00:00
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struct page *page;
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2005-06-24 05:05:25 +00:00
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2007-03-29 08:20:39 +00:00
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page = __xip_sparse_page;
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if (!page)
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return;
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2005-06-24 05:05:25 +00:00
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spin_lock(&mapping->i_mmap_lock);
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vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
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mm = vma->vm_mm;
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address = vma->vm_start +
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((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
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BUG_ON(address < vma->vm_start || address >= vma->vm_end);
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2005-10-30 01:16:31 +00:00
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pte = page_check_address(page, mm, address, &ptl);
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if (pte) {
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2005-06-24 05:05:25 +00:00
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/* Nuke the page table entry. */
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2005-07-12 20:58:18 +00:00
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flush_cache_page(vma, address, pte_pfn(*pte));
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2005-06-24 05:05:25 +00:00
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pteval = ptep_clear_flush(vma, address, pte);
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2006-12-22 09:09:33 +00:00
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page_remove_rmap(page, vma);
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2005-10-30 01:16:12 +00:00
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dec_mm_counter(mm, file_rss);
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2005-06-24 05:05:25 +00:00
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BUG_ON(pte_dirty(pteval));
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2005-10-30 01:16:31 +00:00
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pte_unmap_unlock(pte, ptl);
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2005-10-30 01:16:12 +00:00
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page_cache_release(page);
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2005-06-24 05:05:25 +00:00
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}
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}
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spin_unlock(&mapping->i_mmap_lock);
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}
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/*
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2007-07-19 08:46:59 +00:00
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* xip_fault() is invoked via the vma operations vector for a
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2005-06-24 05:05:25 +00:00
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* mapped memory region to read in file data during a page fault.
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*
|
2007-07-19 08:46:59 +00:00
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* This function is derived from filemap_fault, but used for execute in place
|
2005-06-24 05:05:25 +00:00
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*/
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2007-07-19 08:47:03 +00:00
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static int xip_file_fault(struct vm_area_struct *area, struct vm_fault *vmf)
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2005-06-24 05:05:25 +00:00
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{
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struct file *file = area->vm_file;
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struct address_space *mapping = file->f_mapping;
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struct inode *inode = mapping->host;
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struct page *page;
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2007-07-19 08:46:59 +00:00
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pgoff_t size;
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2005-06-24 05:05:25 +00:00
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2007-07-19 08:46:59 +00:00
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/* XXX: are VM_FAULT_ codes OK? */
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2005-06-24 05:05:25 +00:00
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size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
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2007-07-19 08:47:03 +00:00
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if (vmf->pgoff >= size)
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return VM_FAULT_SIGBUS;
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2005-06-24 05:05:25 +00:00
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2007-07-19 08:46:59 +00:00
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page = mapping->a_ops->get_xip_page(mapping,
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2007-07-19 08:47:03 +00:00
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vmf->pgoff*(PAGE_SIZE/512), 0);
|
2007-03-29 08:20:39 +00:00
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if (!IS_ERR(page))
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2005-10-30 01:16:12 +00:00
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goto out;
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2007-07-19 08:47:03 +00:00
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if (PTR_ERR(page) != -ENODATA)
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return VM_FAULT_OOM;
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2005-06-24 05:05:25 +00:00
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/* sparse block */
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if ((area->vm_flags & (VM_WRITE | VM_MAYWRITE)) &&
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(area->vm_flags & (VM_SHARED| VM_MAYSHARE)) &&
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(!(mapping->host->i_sb->s_flags & MS_RDONLY))) {
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/* maybe shared writable, allocate new block */
|
2007-07-19 08:46:59 +00:00
|
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page = mapping->a_ops->get_xip_page(mapping,
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2007-07-19 08:47:03 +00:00
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vmf->pgoff*(PAGE_SIZE/512), 1);
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if (IS_ERR(page))
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return VM_FAULT_SIGBUS;
|
2005-06-24 05:05:25 +00:00
|
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/* unmap page at pgoff from all other vmas */
|
2007-07-19 08:47:03 +00:00
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__xip_unmap(mapping, vmf->pgoff);
|
2005-06-24 05:05:25 +00:00
|
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} else {
|
2007-03-29 08:20:39 +00:00
|
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/* not shared and writable, use xip_sparse_page() */
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|
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page = xip_sparse_page();
|
2007-07-19 08:47:03 +00:00
|
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if (!page)
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return VM_FAULT_OOM;
|
2005-06-24 05:05:25 +00:00
|
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}
|
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|
2005-10-30 01:16:12 +00:00
|
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out:
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page_cache_get(page);
|
2007-07-19 08:47:03 +00:00
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vmf->page = page;
|
2007-07-19 08:47:05 +00:00
|
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return 0;
|
2005-06-24 05:05:25 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
static struct vm_operations_struct xip_file_vm_ops = {
|
2007-07-19 08:46:59 +00:00
|
|
|
.fault = xip_file_fault,
|
2005-06-24 05:05:25 +00:00
|
|
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};
|
|
|
|
|
|
|
|
int xip_file_mmap(struct file * file, struct vm_area_struct * vma)
|
|
|
|
{
|
|
|
|
BUG_ON(!file->f_mapping->a_ops->get_xip_page);
|
|
|
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|
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file_accessed(file);
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|
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vma->vm_ops = &xip_file_vm_ops;
|
2007-07-19 08:46:59 +00:00
|
|
|
vma->vm_flags |= VM_CAN_NONLINEAR;
|
2005-06-24 05:05:25 +00:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(xip_file_mmap);
|
|
|
|
|
|
|
|
static ssize_t
|
2005-06-24 05:05:28 +00:00
|
|
|
__xip_file_write(struct file *filp, const char __user *buf,
|
|
|
|
size_t count, loff_t pos, loff_t *ppos)
|
2005-06-24 05:05:25 +00:00
|
|
|
{
|
2005-06-24 05:05:28 +00:00
|
|
|
struct address_space * mapping = filp->f_mapping;
|
2006-06-28 11:26:44 +00:00
|
|
|
const struct address_space_operations *a_ops = mapping->a_ops;
|
2005-06-24 05:05:25 +00:00
|
|
|
struct inode *inode = mapping->host;
|
|
|
|
long status = 0;
|
|
|
|
struct page *page;
|
|
|
|
size_t bytes;
|
|
|
|
ssize_t written = 0;
|
|
|
|
|
|
|
|
BUG_ON(!mapping->a_ops->get_xip_page);
|
|
|
|
|
|
|
|
do {
|
|
|
|
unsigned long index;
|
|
|
|
unsigned long offset;
|
|
|
|
size_t copied;
|
2007-10-16 08:24:58 +00:00
|
|
|
char *kaddr;
|
2005-06-24 05:05:25 +00:00
|
|
|
|
|
|
|
offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */
|
|
|
|
index = pos >> PAGE_CACHE_SHIFT;
|
|
|
|
bytes = PAGE_CACHE_SIZE - offset;
|
|
|
|
if (bytes > count)
|
|
|
|
bytes = count;
|
|
|
|
|
|
|
|
page = a_ops->get_xip_page(mapping,
|
2005-06-24 05:05:28 +00:00
|
|
|
index*(PAGE_SIZE/512), 0);
|
2005-06-24 05:05:25 +00:00
|
|
|
if (IS_ERR(page) && (PTR_ERR(page) == -ENODATA)) {
|
|
|
|
/* we allocate a new page unmap it */
|
|
|
|
page = a_ops->get_xip_page(mapping,
|
2005-06-24 05:05:28 +00:00
|
|
|
index*(PAGE_SIZE/512), 1);
|
2005-06-24 05:05:25 +00:00
|
|
|
if (!IS_ERR(page))
|
2005-06-24 05:05:28 +00:00
|
|
|
/* unmap page at pgoff from all other vmas */
|
|
|
|
__xip_unmap(mapping, index);
|
2005-06-24 05:05:25 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
if (IS_ERR(page)) {
|
|
|
|
status = PTR_ERR(page);
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
2007-10-16 08:24:58 +00:00
|
|
|
fault_in_pages_readable(buf, bytes);
|
|
|
|
kaddr = kmap_atomic(page, KM_USER0);
|
|
|
|
copied = bytes -
|
2007-12-05 07:45:25 +00:00
|
|
|
__copy_from_user_inatomic_nocache(kaddr + offset, buf, bytes);
|
2007-10-16 08:24:58 +00:00
|
|
|
kunmap_atomic(kaddr, KM_USER0);
|
2005-06-24 05:05:25 +00:00
|
|
|
flush_dcache_page(page);
|
2007-10-16 08:24:58 +00:00
|
|
|
|
2005-06-24 05:05:25 +00:00
|
|
|
if (likely(copied > 0)) {
|
|
|
|
status = copied;
|
|
|
|
|
|
|
|
if (status >= 0) {
|
|
|
|
written += status;
|
|
|
|
count -= status;
|
|
|
|
pos += status;
|
|
|
|
buf += status;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
if (unlikely(copied != bytes))
|
|
|
|
if (status >= 0)
|
|
|
|
status = -EFAULT;
|
|
|
|
if (status < 0)
|
|
|
|
break;
|
|
|
|
} while (count);
|
|
|
|
*ppos = pos;
|
|
|
|
/*
|
|
|
|
* No need to use i_size_read() here, the i_size
|
2006-01-09 23:59:24 +00:00
|
|
|
* cannot change under us because we hold i_mutex.
|
2005-06-24 05:05:25 +00:00
|
|
|
*/
|
|
|
|
if (pos > inode->i_size) {
|
|
|
|
i_size_write(inode, pos);
|
|
|
|
mark_inode_dirty(inode);
|
|
|
|
}
|
|
|
|
|
|
|
|
return written ? written : status;
|
|
|
|
}
|
|
|
|
|
2005-06-24 05:05:28 +00:00
|
|
|
ssize_t
|
|
|
|
xip_file_write(struct file *filp, const char __user *buf, size_t len,
|
|
|
|
loff_t *ppos)
|
2005-06-24 05:05:25 +00:00
|
|
|
{
|
2005-06-24 05:05:28 +00:00
|
|
|
struct address_space *mapping = filp->f_mapping;
|
|
|
|
struct inode *inode = mapping->host;
|
|
|
|
size_t count;
|
|
|
|
loff_t pos;
|
|
|
|
ssize_t ret;
|
2005-06-24 05:05:25 +00:00
|
|
|
|
2006-01-09 23:59:24 +00:00
|
|
|
mutex_lock(&inode->i_mutex);
|
2005-06-24 05:05:25 +00:00
|
|
|
|
2005-06-24 05:05:28 +00:00
|
|
|
if (!access_ok(VERIFY_READ, buf, len)) {
|
|
|
|
ret=-EFAULT;
|
|
|
|
goto out_up;
|
2005-06-24 05:05:25 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
pos = *ppos;
|
2005-06-24 05:05:28 +00:00
|
|
|
count = len;
|
2005-06-24 05:05:25 +00:00
|
|
|
|
|
|
|
vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
|
|
|
|
|
2005-06-24 05:05:28 +00:00
|
|
|
/* We can write back this queue in page reclaim */
|
|
|
|
current->backing_dev_info = mapping->backing_dev_info;
|
2005-06-24 05:05:25 +00:00
|
|
|
|
2005-06-24 05:05:28 +00:00
|
|
|
ret = generic_write_checks(filp, &pos, &count, S_ISBLK(inode->i_mode));
|
|
|
|
if (ret)
|
|
|
|
goto out_backing;
|
2005-06-24 05:05:25 +00:00
|
|
|
if (count == 0)
|
2005-06-24 05:05:28 +00:00
|
|
|
goto out_backing;
|
2005-06-24 05:05:25 +00:00
|
|
|
|
2006-12-08 10:36:44 +00:00
|
|
|
ret = remove_suid(filp->f_path.dentry);
|
2005-06-24 05:05:28 +00:00
|
|
|
if (ret)
|
|
|
|
goto out_backing;
|
2005-06-24 05:05:25 +00:00
|
|
|
|
2006-01-10 04:52:01 +00:00
|
|
|
file_update_time(filp);
|
2005-06-24 05:05:25 +00:00
|
|
|
|
2005-06-24 05:05:28 +00:00
|
|
|
ret = __xip_file_write (filp, buf, count, pos, ppos);
|
2005-06-24 05:05:25 +00:00
|
|
|
|
2005-06-24 05:05:28 +00:00
|
|
|
out_backing:
|
|
|
|
current->backing_dev_info = NULL;
|
|
|
|
out_up:
|
2006-01-09 23:59:24 +00:00
|
|
|
mutex_unlock(&inode->i_mutex);
|
2005-06-24 05:05:25 +00:00
|
|
|
return ret;
|
|
|
|
}
|
2005-06-24 05:05:28 +00:00
|
|
|
EXPORT_SYMBOL_GPL(xip_file_write);
|
2005-06-24 05:05:25 +00:00
|
|
|
|
|
|
|
/*
|
|
|
|
* truncate a page used for execute in place
|
|
|
|
* functionality is analog to block_truncate_page but does use get_xip_page
|
|
|
|
* to get the page instead of page cache
|
|
|
|
*/
|
|
|
|
int
|
|
|
|
xip_truncate_page(struct address_space *mapping, loff_t from)
|
|
|
|
{
|
|
|
|
pgoff_t index = from >> PAGE_CACHE_SHIFT;
|
|
|
|
unsigned offset = from & (PAGE_CACHE_SIZE-1);
|
|
|
|
unsigned blocksize;
|
|
|
|
unsigned length;
|
|
|
|
struct page *page;
|
|
|
|
|
|
|
|
BUG_ON(!mapping->a_ops->get_xip_page);
|
|
|
|
|
|
|
|
blocksize = 1 << mapping->host->i_blkbits;
|
|
|
|
length = offset & (blocksize - 1);
|
|
|
|
|
|
|
|
/* Block boundary? Nothing to do */
|
|
|
|
if (!length)
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
length = blocksize - length;
|
|
|
|
|
|
|
|
page = mapping->a_ops->get_xip_page(mapping,
|
|
|
|
index*(PAGE_SIZE/512), 0);
|
|
|
|
if (!page)
|
2005-06-24 05:05:28 +00:00
|
|
|
return -ENOMEM;
|
2005-06-24 05:05:25 +00:00
|
|
|
if (unlikely(IS_ERR(page))) {
|
2005-06-24 05:05:28 +00:00
|
|
|
if (PTR_ERR(page) == -ENODATA)
|
2005-06-24 05:05:25 +00:00
|
|
|
/* Hole? No need to truncate */
|
|
|
|
return 0;
|
2005-06-24 05:05:28 +00:00
|
|
|
else
|
|
|
|
return PTR_ERR(page);
|
2005-07-15 10:56:30 +00:00
|
|
|
}
|
2008-02-05 06:28:29 +00:00
|
|
|
zero_user(page, offset, length);
|
2005-06-24 05:05:28 +00:00
|
|
|
return 0;
|
2005-06-24 05:05:25 +00:00
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(xip_truncate_page);
|