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![Tejun Heo](/assets/img/avatar_default.png)
percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
475 lines
11 KiB
C
475 lines
11 KiB
C
/*
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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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#include <linux/mmu_notifier.h>
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#include <linux/sched.h>
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#include <linux/seqlock.h>
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#include <linux/mutex.h>
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#include <linux/gfp.h>
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#include <asm/tlbflush.h>
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#include <asm/io.h>
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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 DEFINE_MUTEX(xip_sparse_mutex);
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static seqcount_t xip_sparse_seq = SEQCNT_ZERO;
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static struct page *__xip_sparse_page;
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/* called under xip_sparse_mutex */
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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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struct page *page = alloc_page(GFP_HIGHUSER | __GFP_ZERO);
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if (page)
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__xip_sparse_page = page;
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}
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return __xip_sparse_page;
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}
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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_mem() 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 ssize_t
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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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char __user *buf,
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size_t len,
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loff_t *ppos)
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{
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struct inode *inode = mapping->host;
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pgoff_t index, end_index;
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unsigned long offset;
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loff_t isize, pos;
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size_t copied = 0, error = 0;
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BUG_ON(!mapping->a_ops->get_xip_mem);
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pos = *ppos;
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index = pos >> PAGE_CACHE_SHIFT;
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offset = pos & ~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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do {
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unsigned long nr, left;
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void *xip_mem;
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unsigned long xip_pfn;
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int zero = 0;
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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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if (nr > len - copied)
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nr = len - copied;
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error = mapping->a_ops->get_xip_mem(mapping, index, 0,
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&xip_mem, &xip_pfn);
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if (unlikely(error)) {
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if (error == -ENODATA) {
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/* sparse */
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zero = 1;
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} else
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goto out;
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}
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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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/* address based flush */ ;
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/*
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* Ok, we have the mem, so now we can copy it to user space...
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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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if (!zero)
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left = __copy_to_user(buf+copied, xip_mem+offset, nr);
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else
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left = __clear_user(buf + copied, nr);
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if (left) {
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error = -EFAULT;
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goto out;
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}
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copied += (nr - left);
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offset += (nr - left);
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index += offset >> PAGE_CACHE_SHIFT;
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offset &= ~PAGE_CACHE_MASK;
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} while (copied < len);
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out:
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*ppos = pos + copied;
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if (filp)
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file_accessed(filp);
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return (copied ? copied : error);
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}
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ssize_t
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xip_file_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos)
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{
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if (!access_ok(VERIFY_WRITE, buf, len))
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return -EFAULT;
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return do_xip_mapping_read(filp->f_mapping, &filp->f_ra, filp,
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buf, len, ppos);
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}
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EXPORT_SYMBOL_GPL(xip_file_read);
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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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* __xip_sparse_page when found at pgoff.
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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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spinlock_t *ptl;
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struct page *page;
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unsigned count;
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int locked = 0;
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count = read_seqcount_begin(&xip_sparse_seq);
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page = __xip_sparse_page;
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if (!page)
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return;
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retry:
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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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pte = page_check_address(page, mm, address, &ptl, 1);
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if (pte) {
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/* Nuke the page table entry. */
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flush_cache_page(vma, address, pte_pfn(*pte));
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pteval = ptep_clear_flush_notify(vma, address, pte);
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page_remove_rmap(page);
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dec_mm_counter(mm, MM_FILEPAGES);
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BUG_ON(pte_dirty(pteval));
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pte_unmap_unlock(pte, ptl);
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page_cache_release(page);
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}
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}
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spin_unlock(&mapping->i_mmap_lock);
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if (locked) {
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mutex_unlock(&xip_sparse_mutex);
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} else if (read_seqcount_retry(&xip_sparse_seq, count)) {
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mutex_lock(&xip_sparse_mutex);
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locked = 1;
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goto retry;
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}
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}
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/*
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* xip_fault() is invoked via the vma operations vector for a
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* mapped memory region to read in file data during a page fault.
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*
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* This function is derived from filemap_fault, but used for execute in place
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*/
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static int xip_file_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
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{
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struct file *file = vma->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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pgoff_t size;
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void *xip_mem;
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unsigned long xip_pfn;
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struct page *page;
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int error;
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/* XXX: are VM_FAULT_ codes OK? */
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again:
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size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
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if (vmf->pgoff >= size)
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return VM_FAULT_SIGBUS;
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error = mapping->a_ops->get_xip_mem(mapping, vmf->pgoff, 0,
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&xip_mem, &xip_pfn);
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if (likely(!error))
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goto found;
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if (error != -ENODATA)
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return VM_FAULT_OOM;
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/* sparse block */
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if ((vma->vm_flags & (VM_WRITE | VM_MAYWRITE)) &&
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(vma->vm_flags & (VM_SHARED | VM_MAYSHARE)) &&
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(!(mapping->host->i_sb->s_flags & MS_RDONLY))) {
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int err;
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/* maybe shared writable, allocate new block */
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mutex_lock(&xip_sparse_mutex);
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error = mapping->a_ops->get_xip_mem(mapping, vmf->pgoff, 1,
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&xip_mem, &xip_pfn);
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mutex_unlock(&xip_sparse_mutex);
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if (error)
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return VM_FAULT_SIGBUS;
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/* unmap sparse mappings at pgoff from all other vmas */
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__xip_unmap(mapping, vmf->pgoff);
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found:
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err = vm_insert_mixed(vma, (unsigned long)vmf->virtual_address,
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xip_pfn);
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if (err == -ENOMEM)
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return VM_FAULT_OOM;
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BUG_ON(err);
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return VM_FAULT_NOPAGE;
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} else {
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int err, ret = VM_FAULT_OOM;
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mutex_lock(&xip_sparse_mutex);
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write_seqcount_begin(&xip_sparse_seq);
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error = mapping->a_ops->get_xip_mem(mapping, vmf->pgoff, 0,
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&xip_mem, &xip_pfn);
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if (unlikely(!error)) {
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write_seqcount_end(&xip_sparse_seq);
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mutex_unlock(&xip_sparse_mutex);
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goto again;
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}
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if (error != -ENODATA)
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goto out;
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/* not shared and writable, use xip_sparse_page() */
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page = xip_sparse_page();
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if (!page)
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goto out;
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err = vm_insert_page(vma, (unsigned long)vmf->virtual_address,
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page);
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if (err == -ENOMEM)
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goto out;
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ret = VM_FAULT_NOPAGE;
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out:
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write_seqcount_end(&xip_sparse_seq);
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mutex_unlock(&xip_sparse_mutex);
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return ret;
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}
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}
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static const struct vm_operations_struct xip_file_vm_ops = {
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.fault = xip_file_fault,
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};
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int xip_file_mmap(struct file * file, struct vm_area_struct * vma)
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{
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BUG_ON(!file->f_mapping->a_ops->get_xip_mem);
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file_accessed(file);
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vma->vm_ops = &xip_file_vm_ops;
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vma->vm_flags |= VM_CAN_NONLINEAR | VM_MIXEDMAP;
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return 0;
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}
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EXPORT_SYMBOL_GPL(xip_file_mmap);
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static ssize_t
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__xip_file_write(struct file *filp, const char __user *buf,
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size_t count, loff_t pos, loff_t *ppos)
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{
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struct address_space * mapping = filp->f_mapping;
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const struct address_space_operations *a_ops = mapping->a_ops;
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struct inode *inode = mapping->host;
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long status = 0;
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size_t bytes;
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ssize_t written = 0;
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BUG_ON(!mapping->a_ops->get_xip_mem);
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do {
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unsigned long index;
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unsigned long offset;
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size_t copied;
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void *xip_mem;
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unsigned long xip_pfn;
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offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */
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index = pos >> PAGE_CACHE_SHIFT;
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bytes = PAGE_CACHE_SIZE - offset;
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if (bytes > count)
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bytes = count;
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status = a_ops->get_xip_mem(mapping, index, 0,
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&xip_mem, &xip_pfn);
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if (status == -ENODATA) {
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/* we allocate a new page unmap it */
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mutex_lock(&xip_sparse_mutex);
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status = a_ops->get_xip_mem(mapping, index, 1,
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&xip_mem, &xip_pfn);
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mutex_unlock(&xip_sparse_mutex);
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if (!status)
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/* unmap page at pgoff from all other vmas */
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__xip_unmap(mapping, index);
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}
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if (status)
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break;
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copied = bytes -
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__copy_from_user_nocache(xip_mem + offset, buf, bytes);
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if (likely(copied > 0)) {
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status = copied;
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if (status >= 0) {
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written += status;
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count -= status;
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pos += status;
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buf += status;
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}
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}
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if (unlikely(copied != bytes))
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if (status >= 0)
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status = -EFAULT;
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if (status < 0)
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break;
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} while (count);
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*ppos = pos;
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/*
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* No need to use i_size_read() here, the i_size
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* cannot change under us because we hold i_mutex.
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*/
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if (pos > inode->i_size) {
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i_size_write(inode, pos);
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mark_inode_dirty(inode);
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}
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return written ? written : status;
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}
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ssize_t
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xip_file_write(struct file *filp, const char __user *buf, size_t len,
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loff_t *ppos)
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{
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struct address_space *mapping = filp->f_mapping;
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struct inode *inode = mapping->host;
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size_t count;
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loff_t pos;
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ssize_t ret;
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mutex_lock(&inode->i_mutex);
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if (!access_ok(VERIFY_READ, buf, len)) {
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ret=-EFAULT;
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goto out_up;
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}
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pos = *ppos;
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count = len;
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vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
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/* We can write back this queue in page reclaim */
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current->backing_dev_info = mapping->backing_dev_info;
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ret = generic_write_checks(filp, &pos, &count, S_ISBLK(inode->i_mode));
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if (ret)
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goto out_backing;
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if (count == 0)
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goto out_backing;
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ret = file_remove_suid(filp);
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if (ret)
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goto out_backing;
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file_update_time(filp);
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ret = __xip_file_write (filp, buf, count, pos, ppos);
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out_backing:
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current->backing_dev_info = NULL;
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out_up:
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mutex_unlock(&inode->i_mutex);
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return ret;
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}
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EXPORT_SYMBOL_GPL(xip_file_write);
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/*
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* truncate a page used for execute in place
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* functionality is analog to block_truncate_page but does use get_xip_mem
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* to get the page instead of page cache
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*/
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int
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xip_truncate_page(struct address_space *mapping, loff_t from)
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{
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pgoff_t index = from >> PAGE_CACHE_SHIFT;
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unsigned offset = from & (PAGE_CACHE_SIZE-1);
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unsigned blocksize;
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unsigned length;
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void *xip_mem;
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unsigned long xip_pfn;
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int err;
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BUG_ON(!mapping->a_ops->get_xip_mem);
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blocksize = 1 << mapping->host->i_blkbits;
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length = offset & (blocksize - 1);
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/* Block boundary? Nothing to do */
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if (!length)
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return 0;
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length = blocksize - length;
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err = mapping->a_ops->get_xip_mem(mapping, index, 0,
|
|
&xip_mem, &xip_pfn);
|
|
if (unlikely(err)) {
|
|
if (err == -ENODATA)
|
|
/* Hole? No need to truncate */
|
|
return 0;
|
|
else
|
|
return err;
|
|
}
|
|
memset(xip_mem + offset, 0, length);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xip_truncate_page);
|