diff options
Diffstat (limited to 'old/xenolinux-2.4.16-sparse/mm')
| -rw-r--r-- | old/xenolinux-2.4.16-sparse/mm/memory.c | 1442 | ||||
| -rw-r--r-- | old/xenolinux-2.4.16-sparse/mm/mremap.c | 354 | ||||
| -rw-r--r-- | old/xenolinux-2.4.16-sparse/mm/swapfile.c | 1291 |
3 files changed, 0 insertions, 3087 deletions
diff --git a/old/xenolinux-2.4.16-sparse/mm/memory.c b/old/xenolinux-2.4.16-sparse/mm/memory.c deleted file mode 100644 index 58eb472e2d..0000000000 --- a/old/xenolinux-2.4.16-sparse/mm/memory.c +++ /dev/null @@ -1,1442 +0,0 @@ -/* - * linux/mm/memory.c - * - * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds - */ - -/* - * demand-loading started 01.12.91 - seems it is high on the list of - * things wanted, and it should be easy to implement. - Linus - */ - -/* - * Ok, demand-loading was easy, shared pages a little bit tricker. Shared - * pages started 02.12.91, seems to work. - Linus. - * - * Tested sharing by executing about 30 /bin/sh: under the old kernel it - * would have taken more than the 6M I have free, but it worked well as - * far as I could see. - * - * Also corrected some "invalidate()"s - I wasn't doing enough of them. - */ - -/* - * Real VM (paging to/from disk) started 18.12.91. Much more work and - * thought has to go into this. Oh, well.. - * 19.12.91 - works, somewhat. Sometimes I get faults, don't know why. - * Found it. Everything seems to work now. - * 20.12.91 - Ok, making the swap-device changeable like the root. - */ - -/* - * 05.04.94 - Multi-page memory management added for v1.1. - * Idea by Alex Bligh (alex@cconcepts.co.uk) - * - * 16.07.99 - Support of BIGMEM added by Gerhard Wichert, Siemens AG - * (Gerhard.Wichert@pdb.siemens.de) - */ - -#include <linux/mm.h> -#include <linux/mman.h> -#include <linux/swap.h> -#include <linux/smp_lock.h> -#include <linux/swapctl.h> -#include <linux/iobuf.h> -#include <linux/highmem.h> -#include <linux/pagemap.h> - -#include <asm/pgalloc.h> -#include <asm/uaccess.h> -#include <asm/tlb.h> - -unsigned long max_mapnr; -unsigned long num_physpages; -void * high_memory; -struct page *highmem_start_page; - -/* - * We special-case the C-O-W ZERO_PAGE, because it's such - * a common occurrence (no need to read the page to know - * that it's zero - better for the cache and memory subsystem). - */ -static inline void copy_cow_page(struct page * from, struct page * to, unsigned long address) -{ - if (from == ZERO_PAGE(address)) { - clear_user_highpage(to, address); - return; - } - copy_user_highpage(to, from, address); -} - -mem_map_t * mem_map; - -/* - * Called by TLB shootdown - */ -void __free_pte(pte_t pte) -{ - struct page *page = pte_page(pte); - if ((!VALID_PAGE(page)) || PageReserved(page)) - return; - if (pte_dirty(pte)) - set_page_dirty(page); - free_page_and_swap_cache(page); -} - - -/* - * Note: this doesn't free the actual pages themselves. That - * has been handled earlier when unmapping all the memory regions. - */ -static inline void free_one_pmd(pmd_t * dir) -{ - pte_t * pte; - - if (pmd_none(*dir)) - return; - if (pmd_bad(*dir)) { - pmd_ERROR(*dir); - pmd_clear(dir); - return; - } - pte = pte_offset(dir, 0); - pmd_clear(dir); - pte_free(pte); -} - -static inline void free_one_pgd(pgd_t * dir) -{ - int j; - pmd_t * pmd; - - if (pgd_none(*dir)) - return; - if (pgd_bad(*dir)) { - pgd_ERROR(*dir); - pgd_clear(dir); - return; - } - pmd = pmd_offset(dir, 0); - pgd_clear(dir); - for (j = 0; j < PTRS_PER_PMD ; j++) { - prefetchw(pmd+j+(PREFETCH_STRIDE/16)); - free_one_pmd(pmd+j); - } - pmd_free(pmd); -} - -/* Low and high watermarks for page table cache. - The system should try to have pgt_water[0] <= cache elements <= pgt_water[1] - */ -int pgt_cache_water[2] = { 25, 50 }; - -/* Returns the number of pages freed */ -int check_pgt_cache(void) -{ - return do_check_pgt_cache(pgt_cache_water[0], pgt_cache_water[1]); -} - - -/* - * This function clears all user-level page tables of a process - this - * is needed by execve(), so that old pages aren't in the way. - */ -void clear_page_tables(struct mm_struct *mm, unsigned long first, int nr) -{ - pgd_t * page_dir = mm->pgd; - - spin_lock(&mm->page_table_lock); - page_dir += first; - do { - free_one_pgd(page_dir); - page_dir++; - } while (--nr); - XENO_flush_page_update_queue(); - spin_unlock(&mm->page_table_lock); - - /* keep the page table cache within bounds */ - check_pgt_cache(); -} - -#define PTE_TABLE_MASK ((PTRS_PER_PTE-1) * sizeof(pte_t)) -#define PMD_TABLE_MASK ((PTRS_PER_PMD-1) * sizeof(pmd_t)) - -/* - * copy one vm_area from one task to the other. Assumes the page tables - * already present in the new task to be cleared in the whole range - * covered by this vma. - * - * 08Jan98 Merged into one routine from several inline routines to reduce - * variable count and make things faster. -jj - * - * dst->page_table_lock is held on entry and exit, - * but may be dropped within pmd_alloc() and pte_alloc(). - */ -int copy_page_range(struct mm_struct *dst, struct mm_struct *src, - struct vm_area_struct *vma) -{ - pgd_t * src_pgd, * dst_pgd; - unsigned long address = vma->vm_start; - unsigned long end = vma->vm_end; - unsigned long cow = (vma->vm_flags & (VM_SHARED | VM_WRITE)) == VM_WRITE; - - src_pgd = pgd_offset(src, address)-1; - dst_pgd = pgd_offset(dst, address)-1; - - for (;;) { - pmd_t * src_pmd, * dst_pmd; - - src_pgd++; dst_pgd++; - - /* copy_pmd_range */ - - if (pgd_none(*src_pgd)) - goto skip_copy_pmd_range; - if (pgd_bad(*src_pgd)) { - pgd_ERROR(*src_pgd); - pgd_clear(src_pgd); -skip_copy_pmd_range: address = (address + PGDIR_SIZE) & PGDIR_MASK; - if (!address || (address >= end)) - goto out; - continue; - } - - src_pmd = pmd_offset(src_pgd, address); - dst_pmd = pmd_alloc(dst, dst_pgd, address); - if (!dst_pmd) - goto nomem; - - do { - pte_t * src_pte, * dst_pte; - - /* copy_pte_range */ - - if (pmd_none(*src_pmd)) - goto skip_copy_pte_range; - if (pmd_bad(*src_pmd)) { - pmd_ERROR(*src_pmd); - pmd_clear(src_pmd); -skip_copy_pte_range: address = (address + PMD_SIZE) & PMD_MASK; - if (address >= end) - goto out; - goto cont_copy_pmd_range; - } - - src_pte = pte_offset(src_pmd, address); - dst_pte = pte_alloc(dst, dst_pmd, address); - if (!dst_pte) - goto nomem; - - spin_lock(&src->page_table_lock); - do { - pte_t pte = *src_pte; - struct page *ptepage; - - /* copy_one_pte */ - - if (pte_none(pte)) - goto cont_copy_pte_range_noset; - if (!pte_present(pte)) { - swap_duplicate(pte_to_swp_entry(pte)); - goto cont_copy_pte_range; - } - ptepage = pte_page(pte); - if ((!VALID_PAGE(ptepage)) || - PageReserved(ptepage)) - goto cont_copy_pte_range; - - /* If it's a COW mapping, write protect it both in the parent and the child */ - if (cow) { - /* XENO modification: modified ordering here to avoid RaW hazard. */ - pte = *src_pte; - pte = pte_wrprotect(pte); - ptep_set_wrprotect(src_pte); - } - - /* If it's a shared mapping, mark it clean in the child */ - if (vma->vm_flags & VM_SHARED) - pte = pte_mkclean(pte); - pte = pte_mkold(pte); - get_page(ptepage); - dst->rss++; - -cont_copy_pte_range: set_pte(dst_pte, pte); -cont_copy_pte_range_noset: address += PAGE_SIZE; - if (address >= end) - goto out_unlock; - src_pte++; - dst_pte++; - } while ((unsigned long)src_pte & PTE_TABLE_MASK); - spin_unlock(&src->page_table_lock); - -cont_copy_pmd_range: src_pmd++; - dst_pmd++; - } while ((unsigned long)src_pmd & PMD_TABLE_MASK); - } -out_unlock: - spin_unlock(&src->page_table_lock); -out: - return 0; -nomem: - return -ENOMEM; -} - -/* - * Return indicates whether a page was freed so caller can adjust rss - */ -static inline void forget_pte(pte_t page) -{ - if (!pte_none(page)) { - printk("forget_pte: old mapping existed!\n"); - BUG(); - } -} - -static inline int zap_pte_range(mmu_gather_t *tlb, pmd_t * pmd, unsigned long address, unsigned long size) -{ - unsigned long offset; - pte_t * ptep; - int freed = 0; - - if (pmd_none(*pmd)) - return 0; - if (pmd_bad(*pmd)) { - pmd_ERROR(*pmd); - pmd_clear(pmd); - return 0; - } - ptep = pte_offset(pmd, address); - offset = address & ~PMD_MASK; - if (offset + size > PMD_SIZE) - size = PMD_SIZE - offset; - size &= PAGE_MASK; - for (offset=0; offset < size; ptep++, offset += PAGE_SIZE) { - pte_t pte = *ptep; - if (pte_none(pte)) - continue; - if (pte_present(pte)) { - struct page *page = pte_page(pte); - if (VALID_PAGE(page) && !PageReserved(page)) - freed ++; - /* This will eventually call __free_pte on the pte. */ - tlb_remove_page(tlb, ptep, address + offset); - } else { - free_swap_and_cache(pte_to_swp_entry(pte)); - pte_clear(ptep); - } - } - - return freed; -} - -static inline int zap_pmd_range(mmu_gather_t *tlb, pgd_t * dir, unsigned long address, unsigned long size) -{ - pmd_t * pmd; - unsigned long end; - int freed; - - if (pgd_none(*dir)) - return 0; - if (pgd_bad(*dir)) { - pgd_ERROR(*dir); - pgd_clear(dir); - return 0; - } - pmd = pmd_offset(dir, address); - end = address + size; - if (end > ((address + PGDIR_SIZE) & PGDIR_MASK)) - end = ((address + PGDIR_SIZE) & PGDIR_MASK); - freed = 0; - do { - freed += zap_pte_range(tlb, pmd, address, end - address); - address = (address + PMD_SIZE) & PMD_MASK; - pmd++; - } while (address < end); - return freed; -} - -/* - * remove user pages in a given range. - */ -void zap_page_range(struct mm_struct *mm, unsigned long address, unsigned long size) -{ - mmu_gather_t *tlb; - pgd_t * dir; - unsigned long start = address, end = address + size; - int freed = 0; - - dir = pgd_offset(mm, address); - - /* - * This is a long-lived spinlock. That's fine. - * There's no contention, because the page table - * lock only protects against kswapd anyway, and - * even if kswapd happened to be looking at this - * process we _want_ it to get stuck. - */ - if (address >= end) - BUG(); - spin_lock(&mm->page_table_lock); - flush_cache_range(mm, address, end); - tlb = tlb_gather_mmu(mm); - - do { - freed += zap_pmd_range(tlb, dir, address, end - address); - address = (address + PGDIR_SIZE) & PGDIR_MASK; - dir++; - } while (address && (address < end)); - - /* this will flush any remaining tlb entries */ - tlb_finish_mmu(tlb, start, end); - - /* - * Update rss for the mm_struct (not necessarily current->mm) - * Notice that rss is an unsigned long. - */ - if (mm->rss > freed) - mm->rss -= freed; - else - mm->rss = 0; - spin_unlock(&mm->page_table_lock); -} - - -/* - * Do a quick page-table lookup for a single page. - */ -static struct page * follow_page(unsigned long address, int write) -{ - pgd_t *pgd; - pmd_t *pmd; - pte_t *ptep, pte; - - pgd = pgd_offset(current->mm, address); - if (pgd_none(*pgd) || pgd_bad(*pgd)) - goto out; - - pmd = pmd_offset(pgd, address); - if (pmd_none(*pmd) || pmd_bad(*pmd)) - goto out; - - ptep = pte_offset(pmd, address); - if (!ptep) - goto out; - - pte = *ptep; - if (pte_present(pte)) { - if (!write || - (pte_write(pte) && pte_dirty(pte))) - return pte_page(pte); - } - -out: - return 0; -} - -/* - * Given a physical address, is there a useful struct page pointing to - * it? This may become more complex in the future if we start dealing - * with IO-aperture pages in kiobufs. - */ - -static inline struct page * get_page_map(struct page *page) -{ - if (!VALID_PAGE(page)) - return 0; - return page; -} - -/* - * Force in an entire range of pages from the current process's user VA, - * and pin them in physical memory. - */ - -#define dprintk(x...) -int map_user_kiobuf(int rw, struct kiobuf *iobuf, unsigned long va, size_t len) -{ - unsigned long ptr, end; - int err; - struct mm_struct * mm; - struct vm_area_struct * vma = 0; - struct page * map; - int i; - int datain = (rw == READ); - - /* Make sure the iobuf is not already mapped somewhere. */ - if (iobuf->nr_pages) - return -EINVAL; - - mm = current->mm; - dprintk ("map_user_kiobuf: begin\n"); - - ptr = va & PAGE_MASK; - end = (va + len + PAGE_SIZE - 1) & PAGE_MASK; - err = expand_kiobuf(iobuf, (end - ptr) >> PAGE_SHIFT); - if (err) - return err; - - down_read(&mm->mmap_sem); - - err = -EFAULT; - iobuf->locked = 0; - iobuf->offset = va & ~PAGE_MASK; - iobuf->length = len; - - i = 0; - - /* - * First of all, try to fault in all of the necessary pages - */ - while (ptr < end) { - if (!vma || ptr >= vma->vm_end) { - vma = find_vma(current->mm, ptr); - if (!vma) - goto out_unlock; - if (vma->vm_start > ptr) { - if (!(vma->vm_flags & VM_GROWSDOWN)) - goto out_unlock; - if (expand_stack(vma, ptr)) - goto out_unlock; - } - if (((datain) && (!(vma->vm_flags & VM_WRITE))) || - (!(vma->vm_flags & VM_READ))) { - err = -EACCES; - goto out_unlock; - } - } - spin_lock(&mm->page_table_lock); - while (!(map = follow_page(ptr, datain))) { - int ret; - - spin_unlock(&mm->page_table_lock); - ret = handle_mm_fault(current->mm, vma, ptr, datain); - if (ret <= 0) { - if (!ret) - goto out_unlock; - else { - err = -ENOMEM; - goto out_unlock; - } - } - spin_lock(&mm->page_table_lock); - } - map = get_page_map(map); - if (map) { - flush_dcache_page(map); - page_cache_get(map); - } else - printk (KERN_INFO "Mapped page missing [%d]\n", i); - spin_unlock(&mm->page_table_lock); - iobuf->maplist[i] = map; - iobuf->nr_pages = ++i; - - ptr += PAGE_SIZE; - } - - up_read(&mm->mmap_sem); - dprintk ("map_user_kiobuf: end OK\n"); - return 0; - - out_unlock: - up_read(&mm->mmap_sem); - unmap_kiobuf(iobuf); - dprintk ("map_user_kiobuf: end %d\n", err); - return err; -} - -/* - * Mark all of the pages in a kiobuf as dirty - * - * We need to be able to deal with short reads from disk: if an IO error - * occurs, the number of bytes read into memory may be less than the - * size of the kiobuf, so we have to stop marking pages dirty once the - * requested byte count has been reached. - */ - -void mark_dirty_kiobuf(struct kiobuf *iobuf, int bytes) -{ - int index, offset, remaining; - struct page *page; - - index = iobuf->offset >> PAGE_SHIFT; - offset = iobuf->offset & ~PAGE_MASK; - remaining = bytes; - if (remaining > iobuf->length) - remaining = iobuf->length; - - while (remaining > 0 && index < iobuf->nr_pages) { - page = iobuf->maplist[index]; - - if (!PageReserved(page)) - SetPageDirty(page); - - remaining -= (PAGE_SIZE - offset); - offset = 0; - index++; - } -} - -/* - * Unmap all of the pages referenced by a kiobuf. We release the pages, - * and unlock them if they were locked. - */ - -void unmap_kiobuf (struct kiobuf *iobuf) -{ - int i; - struct page *map; - - for (i = 0; i < iobuf->nr_pages; i++) { - map = iobuf->maplist[i]; - if (map) { - if (iobuf->locked) - UnlockPage(map); - page_cache_release(map); - } - } - - iobuf->nr_pages = 0; - iobuf->locked = 0; -} - - -/* - * Lock down all of the pages of a kiovec for IO. - * - * If any page is mapped twice in the kiovec, we return the error -EINVAL. - * - * The optional wait parameter causes the lock call to block until all - * pages can be locked if set. If wait==0, the lock operation is - * aborted if any locked pages are found and -EAGAIN is returned. - */ - -int lock_kiovec(int nr, struct kiobuf *iovec[], int wait) -{ - struct kiobuf *iobuf; - int i, j; - struct page *page, **ppage; - int doublepage = 0; - int repeat = 0; - - repeat: - - for (i = 0; i < nr; i++) { - iobuf = iovec[i]; - - if (iobuf->locked) - continue; - - ppage = iobuf->maplist; - for (j = 0; j < iobuf->nr_pages; ppage++, j++) { - page = *ppage; - if (!page) - continue; - - if (TryLockPage(page)) { - while (j--) { - struct page *tmp = *--ppage; - if (tmp) - UnlockPage(tmp); - } - goto retry; - } - } - iobuf->locked = 1; - } - - return 0; - - retry: - - /* - * We couldn't lock one of the pages. Undo the locking so far, - * wait on the page we got to, and try again. - */ - - unlock_kiovec(nr, iovec); - if (!wait) - return -EAGAIN; - - /* - * Did the release also unlock the page we got stuck on? - */ - if (!PageLocked(page)) { - /* - * If so, we may well have the page mapped twice - * in the IO address range. Bad news. Of - * course, it _might_ just be a coincidence, - * but if it happens more than once, chances - * are we have a double-mapped page. - */ - if (++doublepage >= 3) - return -EINVAL; - - /* Try again... */ - wait_on_page(page); - } - - if (++repeat < 16) - goto repeat; - return -EAGAIN; -} - -/* - * Unlock all of the pages of a kiovec after IO. - */ - -int unlock_kiovec(int nr, struct kiobuf *iovec[]) -{ - struct kiobuf *iobuf; - int i, j; - struct page *page, **ppage; - - for (i = 0; i < nr; i++) { - iobuf = iovec[i]; - - if (!iobuf->locked) - continue; - iobuf->locked = 0; - - ppage = iobuf->maplist; - for (j = 0; j < iobuf->nr_pages; ppage++, j++) { - page = *ppage; - if (!page) - continue; - UnlockPage(page); - } - } - return 0; -} - -static inline void zeromap_pte_range(pte_t * pte, unsigned long address, - unsigned long size, pgprot_t prot) -{ - unsigned long end; - - address &= ~PMD_MASK; - end = address + size; - if (end > PMD_SIZE) - end = PMD_SIZE; - do { - pte_t zero_pte = pte_wrprotect(mk_pte(ZERO_PAGE(address), prot)); - pte_t oldpage = ptep_get_and_clear(pte); - set_pte(pte, zero_pte); - forget_pte(oldpage); - address += PAGE_SIZE; - pte++; - } while (address && (address < end)); -} - -static inline int zeromap_pmd_range(struct mm_struct *mm, pmd_t * pmd, unsigned long address, - unsigned long size, pgprot_t prot) -{ - unsigned long end; - - address &= ~PGDIR_MASK; - end = address + size; - if (end > PGDIR_SIZE) - end = PGDIR_SIZE; - do { - pte_t * pte = pte_alloc(mm, pmd, address); - if (!pte) - return -ENOMEM; - zeromap_pte_range(pte, address, end - address, prot); - address = (address + PMD_SIZE) & PMD_MASK; - pmd++; - } while (address && (address < end)); - return 0; -} - -int zeromap_page_range(unsigned long address, unsigned long size, pgprot_t prot) -{ - int error = 0; - pgd_t * dir; - unsigned long beg = address; - unsigned long end = address + size; - struct mm_struct *mm = current->mm; - - dir = pgd_offset(mm, address); - flush_cache_range(mm, beg, end); - if (address >= end) - BUG(); - - spin_lock(&mm->page_table_lock); - do { - pmd_t *pmd = pmd_alloc(mm, dir, address); - error = -ENOMEM; - if (!pmd) - break; - error = zeromap_pmd_range(mm, pmd, address, end - address, prot); - if (error) - break; - address = (address + PGDIR_SIZE) & PGDIR_MASK; - dir++; - } while (address && (address < end)); - spin_unlock(&mm->page_table_lock); - flush_tlb_range(mm, beg, end); - return error; -} - -/* - * maps a range of physical memory into the requested pages. the old - * mappings are removed. any references to nonexistent pages results - * in null mappings (currently treated as "copy-on-access") - */ -static inline void remap_pte_range(pte_t * pte, unsigned long address, unsigned long size, - unsigned long phys_addr, pgprot_t prot) -{ - unsigned long end; - - address &= ~PMD_MASK; - end = address + size; - if (end > PMD_SIZE) - end = PMD_SIZE; - do { - struct page *page; - pte_t oldpage; - oldpage = ptep_get_and_clear(pte); - - page = virt_to_page(__va(phys_addr)); - if ((!VALID_PAGE(page)) || PageReserved(page)) - set_pte(pte, mk_pte_phys(phys_addr, prot)); - forget_pte(oldpage); - address += PAGE_SIZE; - phys_addr += PAGE_SIZE; - pte++; - } while (address && (address < end)); -} - -static inline int remap_pmd_range(struct mm_struct *mm, pmd_t * pmd, unsigned long address, unsigned long size, - unsigned long phys_addr, pgprot_t prot) -{ - unsigned long end; - - address &= ~PGDIR_MASK; - end = address + size; - if (end > PGDIR_SIZE) - end = PGDIR_SIZE; - phys_addr -= address; - do { - pte_t * pte = pte_alloc(mm, pmd, address); - if (!pte) - return -ENOMEM; - remap_pte_range(pte, address, end - address, address + phys_addr, prot); - address = (address + PMD_SIZE) & PMD_MASK; - pmd++; - } while (address && (address < end)); - return 0; -} - -/* Note: this is only safe if the mm semaphore is held when called. */ -int remap_page_range(unsigned long from, unsigned long phys_addr, unsigned long size, pgprot_t prot) -{ - int error = 0; - pgd_t * dir; - unsigned long beg = from; - unsigned long end = from + size; - struct mm_struct *mm = current->mm; - - phys_addr -= from; - dir = pgd_offset(mm, from); - flush_cache_range(mm, beg, end); - if (from >= end) - BUG(); - - spin_lock(&mm->page_table_lock); - do { - pmd_t *pmd = pmd_alloc(mm, dir, from); - error = -ENOMEM; - if (!pmd) - break; - error = remap_pmd_range(mm, pmd, from, end - from, phys_addr + from, prot); - if (error) - break; - from = (from + PGDIR_SIZE) & PGDIR_MASK; - dir++; - } while (from && (from < end)); - spin_unlock(&mm->page_table_lock); - flush_tlb_range(mm, beg, end); - return error; -} - -/* - * Establish a new mapping: - * - flush the old one - * - update the page tables - * - inform the TLB about the new one - * - * We hold the mm semaphore for reading and vma->vm_mm->page_table_lock - */ -static inline void establish_pte(struct vm_area_struct * vma, unsigned long address, pte_t *page_table, pte_t entry) -{ - set_pte(page_table, entry); - flush_tlb_page(vma, address); - update_mmu_cache(vma, address, entry); -} - -/* - * We hold the mm semaphore for reading and vma->vm_mm->page_table_lock - */ -static inline void break_cow(struct vm_area_struct * vma, struct page * new_page, unsigned long address, - pte_t *page_table) -{ - flush_page_to_ram(new_page); - flush_cache_page(vma, address); - establish_pte(vma, address, page_table, pte_mkwrite(pte_mkdirty(mk_pte(new_page, vma->vm_page_prot)))); -} - -/* - * This routine handles present pages, when users try to write - * to a shared page. It is done by copying the page to a new address - * and decrementing the shared-page counter for the old page. - * - * Goto-purists beware: the only reason for goto's here is that it results - * in better assembly code.. The "default" path will see no jumps at all. - * - * Note that this routine assumes that the protection checks have been - * done by the caller (the low-level page fault routine in most cases). - * Thus we can safely just mark it writable once we've done any necessary - * COW. - * - * We also mark the page dirty at this point even though the page will - * change only once the write actually happens. This avoids a few races, - * and potentially makes it more efficient. - * - * We hold the mm semaphore and the page_table_lock on entry and exit - * with the page_table_lock released. - */ -static int do_wp_page(struct mm_struct *mm, struct vm_area_struct * vma, - unsigned long address, pte_t *page_table, pte_t pte) -{ - struct page *old_page, *new_page; - - old_page = pte_page(pte); - if (!VALID_PAGE(old_page)) - goto bad_wp_page; - - if (!TryLockPage(old_page)) { - int reuse = can_share_swap_page(old_page); - unlock_page(old_page); - if (reuse) { - flush_cache_page(vma, address); - establish_pte(vma, address, page_table, pte_mkyoung(pte_mkdirty(pte_mkwrite(pte)))); - spin_unlock(&mm->page_table_lock); - return 1; /* Minor fault */ - } - } - - /* - * Ok, we need to copy. Oh, well.. - */ - page_cache_get(old_page); - spin_unlock(&mm->page_table_lock); - - new_page = alloc_page(GFP_HIGHUSER); - if (!new_page) - goto no_mem; - copy_cow_page(old_page,new_page,address); - - /* - * Re-check the pte - we dropped the lock - */ - spin_lock(&mm->page_table_lock); - if (pte_same(*page_table, pte)) { - if (PageReserved(old_page)) - ++mm->rss; - break_cow(vma, new_page, address, page_table); - lru_cache_add(new_page); - - /* Free the old page.. */ - new_page = old_page; - } - spin_unlock(&mm->page_table_lock); - page_cache_release(new_page); - page_cache_release(old_page); - return 1; /* Minor fault */ - -bad_wp_page: - spin_unlock(&mm->page_table_lock); - printk("do_wp_page: bogus page at address %08lx (page 0x%lx)\n",address,(unsigned long)old_page); - return -1; -no_mem: - page_cache_release(old_page); - return -1; -} - -static void vmtruncate_list(struct vm_area_struct *mpnt, unsigned long pgoff) -{ - do { - struct mm_struct *mm = mpnt->vm_mm; - unsigned long start = mpnt->vm_start; - unsigned long end = mpnt->vm_end; - unsigned long len = end - start; - unsigned long diff; - - /* mapping wholly truncated? */ - if (mpnt->vm_pgoff >= pgoff) { - zap_page_range(mm, start, len); - continue; - } - - /* mapping wholly unaffected? */ - len = len >> PAGE_SHIFT; - diff = pgoff - mpnt->vm_pgoff; - if (diff >= len) - continue; - - /* Ok, partially affected.. */ - start += diff << PAGE_SHIFT; - len = (len - diff) << PAGE_SHIFT; - zap_page_range(mm, start, len); - } while ((mpnt = mpnt->vm_next_share) != NULL); -} - -/* - * Handle all mappings that got truncated by a "truncate()" - * system call. - * - * NOTE! We have to be ready to update the memory sharing - * between the file and the memory map for a potential last - * incomplete page. Ugly, but necessary. - */ -int vmtruncate(struct inode * inode, loff_t offset) -{ - unsigned long pgoff; - struct address_space *mapping = inode->i_mapping; - unsigned long limit; - - if (inode->i_size < offset) - goto do_expand; - inode->i_size = offset; - spin_lock(&mapping->i_shared_lock); - if (!mapping->i_mmap && !mapping->i_mmap_shared) - goto out_unlock; - - pgoff = (offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; - if (mapping->i_mmap != NULL) - vmtruncate_list(mapping->i_mmap, pgoff); - if (mapping->i_mmap_shared != NULL) - vmtruncate_list(mapping->i_mmap_shared, pgoff); - -out_unlock: - spin_unlock(&mapping->i_shared_lock); - truncate_inode_pages(mapping, offset); - goto out_truncate; - -do_expand: - limit = current->rlim[RLIMIT_FSIZE].rlim_cur; - if (limit != RLIM_INFINITY) { - if (inode->i_size >= limit) { - send_sig(SIGXFSZ, current, 0); - goto out; - } - if (offset > limit) { - send_sig(SIGXFSZ, current, 0); - offset = limit; - } - } - inode->i_size = offset; - -out_truncate: - if (inode->i_op && inode->i_op->truncate) { - lock_kernel(); - inode->i_op->truncate(inode); - unlock_kernel(); - } -out: - return 0; -} - -/* - * Primitive swap readahead code. We simply read an aligned block of - * (1 << page_cluster) entries in the swap area. This method is chosen - * because it doesn't cost us any seek time. We also make sure to queue - * the 'original' request together with the readahead ones... - */ -void swapin_readahead(swp_entry_t entry) -{ - int i, num; - struct page *new_page; - unsigned long offset; - - /* - * Get the number of handles we should do readahead io to. - */ - num = valid_swaphandles(entry, &offset); - for (i = 0; i < num; offset++, i++) { - /* Ok, do the async read-ahead now */ - new_page = read_swap_cache_async(SWP_ENTRY(SWP_TYPE(entry), offset)); - if (!new_page) - break; - page_cache_release(new_page); - } - return; -} - -/* - * We hold the mm semaphore and the page_table_lock on entry and - * should release the pagetable lock on exit.. - */ -static int do_swap_page(struct mm_struct * mm, - struct vm_area_struct * vma, unsigned long address, - pte_t * page_table, pte_t orig_pte, int write_access) -{ - struct page *page; - swp_entry_t entry = pte_to_swp_entry(orig_pte); - pte_t pte; - int ret = 1; - - spin_unlock(&mm->page_table_lock); - page = lookup_swap_cache(entry); - if (!page) { - swapin_readahead(entry); - page = read_swap_cache_async(entry); - if (!page) { - /* - * Back out if somebody else faulted in this pte while - * we released the page table lock. - */ - int retval; - spin_lock(&mm->page_table_lock); - retval = pte_same(*page_table, orig_pte) ? -1 : 1; - spin_unlock(&mm->page_table_lock); - return retval; - } - - /* Had to read the page from swap area: Major fault */ - ret = 2; - } - - lock_page(page); - - /* - * Back out if somebody else faulted in this pte while we - * released the page table lock. - */ - spin_lock(&mm->page_table_lock); - if (!pte_same(*page_table, orig_pte)) { - spin_unlock(&mm->page_table_lock); - unlock_page(page); - page_cache_release(page); - return 1; - } - - /* The page isn't present yet, go ahead with the fault. */ - - swap_free(entry); - if (vm_swap_full()) - remove_exclusive_swap_page(page); - - mm->rss++; - pte = mk_pte(page, vma->vm_page_prot); - if (write_access && can_share_swap_page(page)) - pte = pte_mkdirty(pte_mkwrite(pte)); - unlock_page(page); - - flush_page_to_ram(page); - flush_icache_page(vma, page); - set_pte(page_table, pte); - - /* No need to invalidate - it was non-present before */ - update_mmu_cache(vma, address, pte); - XENO_flush_page_update_queue(); - spin_unlock(&mm->page_table_lock); - return ret; -} - -/* - * We are called with the MM semaphore and page_table_lock - * spinlock held to protect against concurrent faults in - * multithreaded programs. - */ -static int do_anonymous_page(struct mm_struct * mm, struct vm_area_struct * vma, pte_t *page_table, int write_access, unsigned long addr) -{ - pte_t entry; - - /* Read-only mapping of ZERO_PAGE. */ - entry = pte_wrprotect(mk_pte(ZERO_PAGE(addr), vma->vm_page_prot)); - - /* ..except if it's a write access */ - if (write_access) { - struct page *page; - - /* Allocate our own private page. */ - spin_unlock(&mm->page_table_lock); - - page = alloc_page(GFP_HIGHUSER); - if (!page) - goto no_mem; - clear_user_highpage(page, addr); - - spin_lock(&mm->page_table_lock); - if (!pte_none(*page_table)) { - page_cache_release(page); - spin_unlock(&mm->page_table_lock); - return 1; - } - mm->rss++; - flush_page_to_ram(page); - entry = pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot))); - lru_cache_add(page); - } - - set_pte(page_table, entry); - - /* No need to invalidate - it was non-present before */ - update_mmu_cache(vma, addr, entry); - XENO_flush_page_update_queue(); - spin_unlock(&mm->page_table_lock); - return 1; /* Minor fault */ - -no_mem: - return -1; -} - -/* - * do_no_page() tries to create a new page mapping. It aggressively - * tries to share with existing pages, but makes a separate copy if - * the "write_access" parameter is true in order to avoid the next - * page fault. - * - * As this is called only for pages that do not currently exist, we - * do not need to flush old virtual caches or the TLB. - * - * This is called with the MM semaphore held and the page table - * spinlock held. Exit with the spinlock released. - */ -static int do_no_page(struct mm_struct * mm, struct vm_area_struct * vma, - unsigned long address, int write_access, pte_t *page_table) -{ - struct page * new_page; - pte_t entry; - - if (!vma->vm_ops || !vma->vm_ops->nopage) - return do_anonymous_page(mm, vma, page_table, write_access, address); - spin_unlock(&mm->page_table_lock); - - new_page = vma->vm_ops->nopage(vma, address & PAGE_MASK, 0); - - if (new_page == NULL) /* no page was available -- SIGBUS */ - return 0; - if (new_page == NOPAGE_OOM) - return -1; - - /* - * Should we do an early C-O-W break? - */ - if (write_access && !(vma->vm_flags & VM_SHARED)) { - struct page * page = alloc_page(GFP_HIGHUSER); - if (!page) - return -1; - copy_highpage(page, new_page); - page_cache_release(new_page); - lru_cache_add(page); - new_page = page; - } - - spin_lock(&mm->page_table_lock); - /* - * This silly early PAGE_DIRTY setting removes a race - * due to the bad i386 page protection. But it's valid - * for other architectures too. - * - * Note that if write_access is true, we either now have - * an exclusive copy of the page, or this is a shared mapping, - * so we can make it writable and dirty to avoid having to - * handle that later. - */ - /* Only go through if we didn't race with anybody else... */ - if (pte_none(*page_table)) { - ++mm->rss; - flush_page_to_ram(new_page); - flush_icache_page(vma, new_page); - entry = mk_pte(new_page, vma->vm_page_prot); - if (write_access) - entry = pte_mkwrite(pte_mkdirty(entry)); - set_pte(page_table, entry); - } else { - /* One of our sibling threads was faster, back out. */ - page_cache_release(new_page); - spin_unlock(&mm->page_table_lock); - return 1; - } - - /* no need to invalidate: a not-present page shouldn't be cached */ - update_mmu_cache(vma, address, entry); - XENO_flush_page_update_queue(); - spin_unlock(&mm->page_table_lock); - return 2; /* Major fault */ -} - -/* - * These routines also need to handle stuff like marking pages dirty - * and/or accessed for architectures that don't do it in hardware (most - * RISC architectures). The early dirtying is also good on the i386. - * - * There is also a hook called "update_mmu_cache()" that architectures - * with external mmu caches can use to update those (ie the Sparc or - * PowerPC hashed page tables that act as extended TLBs). - * - * Note the "page_table_lock". It is to protect against kswapd removing - * pages from under us. Note that kswapd only ever _removes_ pages, never - * adds them. As such, once we have noticed that the page is not present, - * we can drop the lock early. - * - * The adding of pages is protected by the MM semaphore (which we hold), - * so we don't need to worry about a page being suddenly been added into - * our VM. - * - * We enter with the pagetable spinlock held, we are supposed to - * release it when done. - */ -static inline int handle_pte_fault(struct mm_struct *mm, - struct vm_area_struct * vma, unsigned long address, - int write_access, pte_t * pte) -{ - pte_t entry; - - entry = *pte; - if (!pte_present(entry)) { - /* - * If it truly wasn't present, we know that kswapd - * and the PTE updates will not touch it later. So - * drop the lock. - */ - if (pte_none(entry)) - return do_no_page(mm, vma, address, write_access, pte); - return do_swap_page(mm, vma, address, pte, entry, write_access); - } - - if (write_access) { - if (!pte_write(entry)) - return do_wp_page(mm, vma, address, pte, entry); - - entry = pte_mkdirty(entry); - } - entry = pte_mkyoung(entry); - establish_pte(vma, address, pte, entry); - XENO_flush_page_update_queue(); - spin_unlock(&mm->page_table_lock); - return 1; -} - -/* - * By the time we get here, we already hold the mm semaphore - */ -int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct * vma, - unsigned long address, int write_access) -{ - pgd_t *pgd; - pmd_t *pmd; - - current->state = TASK_RUNNING; - pgd = pgd_offset(mm, address); - - /* - * We need the page table lock to synchronize with kswapd - * and the SMP-safe atomic PTE updates. - */ - spin_lock(&mm->page_table_lock); - pmd = pmd_alloc(mm, pgd, address); - - if (pmd) { - pte_t * pte = pte_alloc(mm, pmd, address); - if (pte) - return handle_pte_fault(mm, vma, address, write_access, pte); - } - spin_unlock(&mm->page_table_lock); - return -1; -} - -/* - * Allocate page middle directory. - * - * We've already handled the fast-path in-line, and we own the - * page table lock. - * - * On a two-level page table, this ends up actually being entirely - * optimized away. - */ -pmd_t *__pmd_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address) -{ - pmd_t *new; - - /* "fast" allocation can happen without dropping the lock.. */ - new = pmd_alloc_one_fast(mm, address); - if (!new) { - spin_unlock(&mm->page_table_lock); - new = pmd_alloc_one(mm, address); - spin_lock(&mm->page_table_lock); - if (!new) - return NULL; - - /* - * Because we dropped the lock, we should re-check the - * entry, as somebody else could have populated it.. - */ - if (!pgd_none(*pgd)) { - pmd_free(new); - goto out; - } - } - pgd_populate(mm, pgd, new); -out: - return pmd_offset(pgd, address); -} - -/* - * Allocate the page table directory. - * - * We've already handled the fast-path in-line, and we own the - * page table lock. - */ -pte_t *pte_alloc(struct mm_struct *mm, pmd_t *pmd, unsigned long address) -{ - if (pmd_none(*pmd)) { - pte_t *new; - - /* "fast" allocation can happen without dropping the lock.. */ - new = pte_alloc_one_fast(mm, address); - if (!new) { - XENO_flush_page_update_queue(); - spin_unlock(&mm->page_table_lock); - new = pte_alloc_one(mm, address); - spin_lock(&mm->page_table_lock); - if (!new) - return NULL; - - /* - * Because we dropped the lock, we should re-check the - * entry, as somebody else could have populated it.. - */ - if (!pmd_none(*pmd)) { - pte_free(new); - goto out; - } - } - pmd_populate(mm, pmd, new); - } -out: - return pte_offset(pmd, address); -} - -/* - * Simplistic page force-in.. - */ -int make_pages_present(unsigned long addr, unsigned long end) -{ - int write; - struct mm_struct *mm = current->mm; - struct vm_area_struct * vma; - - vma = find_vma(mm, addr); - write = (vma->vm_flags & VM_WRITE) != 0; - if (addr >= end) - BUG(); - do { - if (handle_mm_fault(mm, vma, addr, write) < 0) - return -1; - addr += PAGE_SIZE; - } while (addr < end); - return 0; -} diff --git a/old/xenolinux-2.4.16-sparse/mm/mremap.c b/old/xenolinux-2.4.16-sparse/mm/mremap.c deleted file mode 100644 index a2e0d860dd..0000000000 --- a/old/xenolinux-2.4.16-sparse/mm/mremap.c +++ /dev/null @@ -1,354 +0,0 @@ -/* - * linux/mm/remap.c - * - * (C) Copyright 1996 Linus Torvalds - */ - -#include <linux/slab.h> -#include <linux/smp_lock.h> -#include <linux/shm.h> -#include <linux/mman.h> -#include <linux/swap.h> - -#include <asm/uaccess.h> -#include <asm/pgalloc.h> - -extern int vm_enough_memory(long pages); - -static inline pte_t *get_one_pte(struct mm_struct *mm, unsigned long addr) -{ - pgd_t * pgd; - pmd_t * pmd; - pte_t * pte = NULL; - - pgd = pgd_offset(mm, addr); - if (pgd_none(*pgd)) - goto end; - if (pgd_bad(*pgd)) { - pgd_ERROR(*pgd); - pgd_clear(pgd); - goto end; - } - - pmd = pmd_offset(pgd, addr); - if (pmd_none(*pmd)) - goto end; - if (pmd_bad(*pmd)) { - pmd_ERROR(*pmd); - pmd_clear(pmd); - goto end; - } - - pte = pte_offset(pmd, addr); - if (pte_none(*pte)) - pte = NULL; -end: - return pte; -} - -static inline pte_t *alloc_one_pte(struct mm_struct *mm, unsigned long addr) -{ - pmd_t * pmd; - pte_t * pte = NULL; - - pmd = pmd_alloc(mm, pgd_offset(mm, addr), addr); - if (pmd) - pte = pte_alloc(mm, pmd, addr); - return pte; -} - -static inline int copy_one_pte(struct mm_struct *mm, pte_t * src, pte_t * dst) -{ - int error = 0; - pte_t pte; - - if (!pte_none(*src)) { - pte = ptep_get_and_clear(src); - if (!dst) { - /* No dest? We must put it back. */ - dst = src; - error++; - } - set_pte(dst, pte); - } - return error; -} - -static int move_one_page(struct mm_struct *mm, unsigned long old_addr, unsigned long new_addr) -{ - int error = 0; - pte_t * src; - - spin_lock(&mm->page_table_lock); - src = get_one_pte(mm, old_addr); - if (src) - error = copy_one_pte(mm, src, alloc_one_pte(mm, new_addr)); - spin_unlock(&mm->page_table_lock); - return error; -} - -static int move_page_tables(struct mm_struct * mm, - unsigned long new_addr, unsigned long old_addr, unsigned long len) -{ - unsigned long offset = len; - - flush_cache_range(mm, old_addr, old_addr + len); - - /* - * This is not the clever way to do this, but we're taking the - * easy way out on the assumption that most remappings will be - * only a few pages.. This also makes error recovery easier. - */ - while (offset) { - offset -= PAGE_SIZE; - if (move_one_page(mm, old_addr + offset, new_addr + offset)) - goto oops_we_failed; - } - flush_tlb_range(mm, old_addr, old_addr + len); - return 0; - - /* - * Ok, the move failed because we didn't have enough pages for - * the new page table tree. This is unlikely, but we have to - * take the possibility into account. In that case we just move - * all the pages back (this will work, because we still have - * the old page tables) - */ -oops_we_failed: - XENO_flush_page_update_queue(); - flush_cache_range(mm, new_addr, new_addr + len); - while ((offset += PAGE_SIZE) < len) - move_one_page(mm, new_addr + offset, old_addr + offset); - XENO_flush_page_update_queue(); - zap_page_range(mm, new_addr, len); - return -1; -} - -static inline unsigned long move_vma(struct vm_area_struct * vma, - unsigned long addr, unsigned long old_len, unsigned long new_len, - unsigned long new_addr) -{ - struct mm_struct * mm = vma->vm_mm; - struct vm_area_struct * new_vma, * next, * prev; - int allocated_vma; - - new_vma = NULL; - next = find_vma_prev(mm, new_addr, &prev); - if (next) { - if (prev && prev->vm_end == new_addr && - can_vma_merge(prev, vma->vm_flags) && !vma->vm_file && !(vma->vm_flags & VM_SHARED)) { - spin_lock(&mm->page_table_lock); - prev->vm_end = new_addr + new_len; - spin_unlock(&mm->page_table_lock); - new_vma = prev; - if (next != prev->vm_next) - BUG(); - if (prev->vm_end == next->vm_start && can_vma_merge(next, prev->vm_flags)) { - spin_lock(&mm->page_table_lock); - prev->vm_end = next->vm_end; - __vma_unlink(mm, next, prev); - spin_unlock(&mm->page_table_lock); - - mm->map_count--; - kmem_cache_free(vm_area_cachep, next); - } - } else if (next->vm_start == new_addr + new_len && - can_vma_merge(next, vma->vm_flags) && !vma->vm_file && !(vma->vm_flags & VM_SHARED)) { - spin_lock(&mm->page_table_lock); - next->vm_start = new_addr; - spin_unlock(&mm->page_table_lock); - new_vma = next; - } - } else { - prev = find_vma(mm, new_addr-1); - if (prev && prev->vm_end == new_addr && - can_vma_merge(prev, vma->vm_flags) && !vma->vm_file && !(vma->vm_flags & VM_SHARED)) { - spin_lock(&mm->page_table_lock); - prev->vm_end = new_addr + new_len; - spin_unlock(&mm->page_table_lock); - new_vma = prev; - } - } - - allocated_vma = 0; - if (!new_vma) { - new_vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL); - if (!new_vma) - goto out; - allocated_vma = 1; - } - - if (!move_page_tables(current->mm, new_addr, addr, old_len)) { - if (allocated_vma) { - *new_vma = *vma; - new_vma->vm_start = new_addr; - new_vma->vm_end = new_addr+new_len; - new_vma->vm_pgoff += (addr - vma->vm_start) >> PAGE_SHIFT; - new_vma->vm_raend = 0; - if (new_vma->vm_file) - get_file(new_vma->vm_file); - if (new_vma->vm_ops && new_vma->vm_ops->open) - new_vma->vm_ops->open(new_vma); - insert_vm_struct(current->mm, new_vma); - } - do_munmap(current->mm, addr, old_len); - current->mm->total_vm += new_len >> PAGE_SHIFT; - if (new_vma->vm_flags & VM_LOCKED) { - current->mm->locked_vm += new_len >> PAGE_SHIFT; - make_pages_present(new_vma->vm_start, - new_vma->vm_end); - } - return new_addr; - } - if (allocated_vma) - kmem_cache_free(vm_area_cachep, new_vma); - out: - return -ENOMEM; -} - -/* - * Expand (or shrink) an existing mapping, potentially moving it at the - * same time (controlled by the MREMAP_MAYMOVE flag and available VM space) - * - * MREMAP_FIXED option added 5-Dec-1999 by Benjamin LaHaise - * This option implies MREMAP_MAYMOVE. - */ -unsigned long do_mremap(unsigned long addr, - unsigned long old_len, unsigned long new_len, - unsigned long flags, unsigned long new_addr) -{ - struct vm_area_struct *vma; - unsigned long ret = -EINVAL; - - if (flags & ~(MREMAP_FIXED | MREMAP_MAYMOVE)) - goto out; - - if (addr & ~PAGE_MASK) - goto out; - - old_len = PAGE_ALIGN(old_len); - new_len = PAGE_ALIGN(new_len); - - /* new_addr is only valid if MREMAP_FIXED is specified */ - if (flags & MREMAP_FIXED) { - if (new_addr & ~PAGE_MASK) - goto out; - if (!(flags & MREMAP_MAYMOVE)) - goto out; - - if (new_len > TASK_SIZE || new_addr > TASK_SIZE - new_len) - goto out; - - /* Check if the location we're moving into overlaps the - * old location at all, and fail if it does. - */ - if ((new_addr <= addr) && (new_addr+new_len) > addr) - goto out; - - if ((addr <= new_addr) && (addr+old_len) > new_addr) - goto out; - - do_munmap(current->mm, new_addr, new_len); - } - - /* - * Always allow a shrinking remap: that just unmaps - * the unnecessary pages.. - */ - ret = addr; - if (old_len >= new_len) { - do_munmap(current->mm, addr+new_len, old_len - new_len); - if (!(flags & MREMAP_FIXED) || (new_addr == addr)) - goto out; - } - - /* - * Ok, we need to grow.. or relocate. - */ - ret = -EFAULT; - vma = find_vma(current->mm, addr); - if (!vma || vma->vm_start > addr) - goto out; - /* We can't remap across vm area boundaries */ - if (old_len > vma->vm_end - addr) - goto out; - if (vma->vm_flags & VM_DONTEXPAND) { - if (new_len > old_len) - goto out; - } - if (vma->vm_flags & VM_LOCKED) { - unsigned long locked = current->mm->locked_vm << PAGE_SHIFT; - locked += new_len - old_len; - ret = -EAGAIN; - if (locked > current->rlim[RLIMIT_MEMLOCK].rlim_cur) - goto out; - } - ret = -ENOMEM; - if ((current->mm->total_vm << PAGE_SHIFT) + (new_len - old_len) - > current->rlim[RLIMIT_AS].rlim_cur) - goto out; - /* Private writable mapping? Check memory availability.. */ - if ((vma->vm_flags & (VM_SHARED | VM_WRITE)) == VM_WRITE && - !(flags & MAP_NORESERVE) && - !vm_enough_memory((new_len - old_len) >> PAGE_SHIFT)) - goto out; - - /* old_len exactly to the end of the area.. - * And we're not relocating the area. - */ - if (old_len == vma->vm_end - addr && - !((flags & MREMAP_FIXED) && (addr != new_addr)) && - (old_len != new_len || !(flags & MREMAP_MAYMOVE))) { - unsigned long max_addr = TASK_SIZE; - if (vma->vm_next) - max_addr = vma->vm_next->vm_start; - /* can we just expand the current mapping? */ - if (max_addr - addr >= new_len) { - int pages = (new_len - old_len) >> PAGE_SHIFT; - spin_lock(&vma->vm_mm->page_table_lock); - vma->vm_end = addr + new_len; - spin_unlock(&vma->vm_mm->page_table_lock); - current->mm->total_vm += pages; - if (vma->vm_flags & VM_LOCKED) { - current->mm->locked_vm += pages; - make_pages_present(addr + old_len, - addr + new_len); - } - ret = addr; - goto out; - } - } - - /* - * We weren't able to just expand or shrink the area, - * we need to create a new one and move it.. - */ - ret = -ENOMEM; - if (flags & MREMAP_MAYMOVE) { - if (!(flags & MREMAP_FIXED)) { - unsigned long map_flags = 0; - if (vma->vm_flags & VM_SHARED) - map_flags |= MAP_SHARED; - - new_addr = get_unmapped_area(vma->vm_file, 0, new_len, vma->vm_pgoff, map_flags); - ret = new_addr; - if (new_addr & ~PAGE_MASK) - goto out; - } - ret = move_vma(vma, addr, old_len, new_len, new_addr); - } -out: - return ret; -} - -asmlinkage unsigned long sys_mremap(unsigned long addr, - unsigned long old_len, unsigned long new_len, - unsigned long flags, unsigned long new_addr) -{ - unsigned long ret; - - down_write(¤t->mm->mmap_sem); - ret = do_mremap(addr, old_len, new_len, flags, new_addr); - up_write(¤t->mm->mmap_sem); - return ret; -} diff --git a/old/xenolinux-2.4.16-sparse/mm/swapfile.c b/old/xenolinux-2.4.16-sparse/mm/swapfile.c deleted file mode 100644 index 48846184d4..0000000000 --- a/old/xenolinux-2.4.16-sparse/mm/swapfile.c +++ /dev/null @@ -1,1291 +0,0 @@ -/* - * linux/mm/swapfile.c - * - * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds - * Swap reorganised 29.12.95, Stephen Tweedie - */ - -#include <linux/slab.h> -#include <linux/smp_lock.h> -#include <linux/kernel_stat.h> -#include <linux/swap.h> -#include <linux/swapctl.h> -#include <linux/blkdev.h> /* for blk_size */ -#include <linux/vmalloc.h> -#include <linux/pagemap.h> -#include <linux/shm.h> -#include <linux/compiler.h> - -#include <asm/pgtable.h> - -spinlock_t swaplock = SPIN_LOCK_UNLOCKED; -unsigned int nr_swapfiles; -int total_swap_pages; -static int swap_overflow; - -static const char Bad_file[] = "Bad swap file entry "; -static const char Unused_file[] = "Unused swap file entry "; -static const char Bad_offset[] = "Bad swap offset entry "; -static const char Unused_offset[] = "Unused swap offset entry "; - -struct swap_list_t swap_list = {-1, -1}; - -struct swap_info_struct swap_info[MAX_SWAPFILES]; - -#define SWAPFILE_CLUSTER 256 - -static inline int scan_swap_map(struct swap_info_struct *si) -{ - unsigned long offset; - /* - * We try to cluster swap pages by allocating them - * sequentially in swap. Once we've allocated - * SWAPFILE_CLUSTER pages this way, however, we resort to - * first-free allocation, starting a new cluster. This - * prevents us from scattering swap pages all over the entire - * swap partition, so that we reduce overall disk seek times - * between swap pages. -- sct */ - if (si->cluster_nr) { - while (si->cluster_next <= si->highest_bit) { - offset = si->cluster_next++; - if (si->swap_map[offset]) - continue; - si->cluster_nr--; - goto got_page; - } - } - si->cluster_nr = SWAPFILE_CLUSTER; - - /* try to find an empty (even not aligned) cluster. */ - offset = si->lowest_bit; - check_next_cluster: - if (offset+SWAPFILE_CLUSTER-1 <= si->highest_bit) - { - int nr; - for (nr = offset; nr < offset+SWAPFILE_CLUSTER; nr++) - if (si->swap_map[nr]) - { - offset = nr+1; - goto check_next_cluster; - } - /* We found a completly empty cluster, so start - * using it. - */ - goto got_page; - } - /* No luck, so now go finegrined as usual. -Andrea */ - for (offset = si->lowest_bit; offset <= si->highest_bit ; offset++) { - if (si->swap_map[offset]) - continue; - si->lowest_bit = offset+1; - got_page: - if (offset == si->lowest_bit) - si->lowest_bit++; - if (offset == si->highest_bit) - si->highest_bit--; - if (si->lowest_bit > si->highest_bit) { - si->lowest_bit = si->max; - si->highest_bit = 0; - } - si->swap_map[offset] = 1; - nr_swap_pages--; - si->cluster_next = offset+1; - return offset; - } - si->lowest_bit = si->max; - si->highest_bit = 0; - return 0; -} - -swp_entry_t get_swap_page(void) -{ - struct swap_info_struct * p; - unsigned long offset; - swp_entry_t entry; - int type, wrapped = 0; - - entry.val = 0; /* Out of memory */ - swap_list_lock(); - type = swap_list.next; - if (type < 0) - goto out; - if (nr_swap_pages <= 0) - goto out; - - while (1) { - p = &swap_info[type]; - if ((p->flags & SWP_WRITEOK) == SWP_WRITEOK) { - swap_device_lock(p); - offset = scan_swap_map(p); - swap_device_unlock(p); - if (offset) { - entry = SWP_ENTRY(type,offset); - type = swap_info[type].next; - if (type < 0 || - p->prio != swap_info[type].prio) { - swap_list.next = swap_list.head; - } else { - swap_list.next = type; - } - goto out; - } - } - type = p->next; - if (!wrapped) { - if (type < 0 || p->prio != swap_info[type].prio) { - type = swap_list.head; - wrapped = 1; - } - } else - if (type < 0) - goto out; /* out of swap space */ - } -out: - swap_list_unlock(); - return entry; -} - -static struct swap_info_struct * swap_info_get(swp_entry_t entry) -{ - struct swap_info_struct * p; - unsigned long offset, type; - - if (!entry.val) - goto out; - type = SWP_TYPE(entry); - if (type >= nr_swapfiles) - goto bad_nofile; - p = & swap_info[type]; - if (!(p->flags & SWP_USED)) - goto bad_device; - offset = SWP_OFFSET(entry); - if (offset >= p->max) - goto bad_offset; - if (!p->swap_map[offset]) - goto bad_free; - swap_list_lock(); - if (p->prio > swap_info[swap_list.next].prio) - swap_list.next = type; - swap_device_lock(p); - return p; - -bad_free: - printk(KERN_ERR "swap_free: %s%08lx\n", Unused_offset, entry.val); - goto out; -bad_offset: - printk(KERN_ERR "swap_free: %s%08lx\n", Bad_offset, entry.val); - goto out; -bad_device: - printk(KERN_ERR "swap_free: %s%08lx\n", Unused_file, entry.val); - goto out; -bad_nofile: - printk(KERN_ERR "swap_free: %s%08lx\n", Bad_file, entry.val); -out: - return NULL; -} - -static void swap_info_put(struct swap_info_struct * p) -{ - swap_device_unlock(p); - swap_list_unlock(); -} - -static int swap_entry_free(struct swap_info_struct *p, unsigned long offset) -{ - int count = p->swap_map[offset]; - - if (count < SWAP_MAP_MAX) { - count--; - p->swap_map[offset] = count; - if (!count) { - if (offset < p->lowest_bit) - p->lowest_bit = offset; - if (offset > p->highest_bit) - p->highest_bit = offset; - nr_swap_pages++; - } - } - return count; -} - -/* - * Caller has made sure that the swapdevice corresponding to entry - * is still around or has not been recycled. - */ -void swap_free(swp_entry_t entry) -{ - struct swap_info_struct * p; - - p = swap_info_get(entry); - if (p) { - swap_entry_free(p, SWP_OFFSET(entry)); - swap_info_put(p); - } -} - -/* - * Check if we're the only user of a swap page, - * when the page is locked. - */ -static int exclusive_swap_page(struct page *page) -{ - int retval = 0; - struct swap_info_struct * p; - swp_entry_t entry; - - entry.val = page->index; - p = swap_info_get(entry); - if (p) { - /* Is the only swap cache user the cache itself? */ - if (p->swap_map[SWP_OFFSET(entry)] == 1) { - /* Recheck the page count with the pagecache lock held.. */ - spin_lock(&pagecache_lock); - if (page_count(page) - !!page->buffers == 2) - retval = 1; - spin_unlock(&pagecache_lock); - } - swap_info_put(p); - } - return retval; -} - -/* - * We can use this swap cache entry directly - * if there are no other references to it. - * - * Here "exclusive_swap_page()" does the real - * work, but we opportunistically check whether - * we need to get all the locks first.. - */ -int can_share_swap_page(struct page *page) -{ - int retval = 0; - - if (!PageLocked(page)) - BUG(); - switch (page_count(page)) { - case 3: - if (!page->buffers) - break; - /* Fallthrough */ - case 2: - if (!PageSwapCache(page)) - break; - retval = exclusive_swap_page(page); - break; - case 1: - if (PageReserved(page)) - break; - retval = 1; - } - return retval; -} - -/* - * Work out if there are any other processes sharing this - * swap cache page. Free it if you can. Return success. - */ -int remove_exclusive_swap_page(struct page *page) -{ - int retval; - struct swap_info_struct * p; - swp_entry_t entry; - - if (!PageLocked(page)) - BUG(); - if (!PageSwapCache(page)) - return 0; - if (page_count(page) - !!page->buffers != 2) /* 2: us + cache */ - return 0; - - entry.val = page->index; - p = swap_info_get(entry); - if (!p) - return 0; - - /* Is the only swap cache user the cache itself? */ - retval = 0; - if (p->swap_map[SWP_OFFSET(entry)] == 1) { - /* Recheck the page count with the pagecache lock held.. */ - spin_lock(&pagecache_lock); - if (page_count(page) - !!page->buffers == 2) { - __delete_from_swap_cache(page); - SetPageDirty(page); - retval = 1; - } - spin_unlock(&pagecache_lock); - } - swap_info_put(p); - - if (retval) { - block_flushpage(page, 0); - swap_free(entry); - page_cache_release(page); - } - - return retval; -} - -/* - * Free the swap entry like above, but also try to - * free the page cache entry if it is the last user. - */ -void free_swap_and_cache(swp_entry_t entry) -{ - struct swap_info_struct * p; - struct page *page = NULL; - - p = swap_info_get(entry); - if (p) { - if (swap_entry_free(p, SWP_OFFSET(entry)) == 1) - page = find_trylock_page(&swapper_space, entry.val); - swap_info_put(p); - } - if (page) { - page_cache_get(page); - /* Only cache user (+us), or swap space full? Free it! */ - if (page_count(page) == 2 || vm_swap_full()) { - delete_from_swap_cache(page); - SetPageDirty(page); - } - UnlockPage(page); - page_cache_release(page); - } -} - -/* - * The swap entry has been read in advance, and we return 1 to indicate - * that the page has been used or is no longer needed. - * - * Always set the resulting pte to be nowrite (the same as COW pages - * after one process has exited). We don't know just how many PTEs will - * share this swap entry, so be cautious and let do_wp_page work out - * what to do if a write is requested later. - */ -/* mmlist_lock and vma->vm_mm->page_table_lock are held */ -static inline void unuse_pte(struct vm_area_struct * vma, unsigned long address, - pte_t *dir, swp_entry_t entry, struct page* page) -{ - pte_t pte = *dir; - - if (likely(pte_to_swp_entry(pte).val != entry.val)) - return; - if (unlikely(pte_none(pte) || pte_present(pte))) - return; - get_page(page); - set_pte(dir, pte_mkold(mk_pte(page, vma->vm_page_prot))); - swap_free(entry); - ++vma->vm_mm->rss; -} - -/* mmlist_lock and vma->vm_mm->page_table_lock are held */ -static inline void unuse_pmd(struct vm_area_struct * vma, pmd_t *dir, - unsigned long address, unsigned long size, unsigned long offset, - swp_entry_t entry, struct page* page) -{ - pte_t * pte; - unsigned long end; - - if (pmd_none(*dir)) - return; - if (pmd_bad(*dir)) { - pmd_ERROR(*dir); - pmd_clear(dir); - return; - } - pte = pte_offset(dir, address); - offset += address & PMD_MASK; - address &= ~PMD_MASK; - end = address + size; - if (end > PMD_SIZE) - end = PMD_SIZE; - do { - unuse_pte(vma, offset+address-vma->vm_start, pte, entry, page); - address += PAGE_SIZE; - pte++; - } while (address && (address < end)); -} - -/* mmlist_lock and vma->vm_mm->page_table_lock are held */ -static inline void unuse_pgd(struct vm_area_struct * vma, pgd_t *dir, - unsigned long address, unsigned long size, - swp_entry_t entry, struct page* page) -{ - pmd_t * pmd; - unsigned long offset, end; - - if (pgd_none(*dir)) - return; - if (pgd_bad(*dir)) { - pgd_ERROR(*dir); - pgd_clear(dir); - return; - } - pmd = pmd_offset(dir, address); - offset = address & PGDIR_MASK; - address &= ~PGDIR_MASK; - end = address + size; - if (end > PGDIR_SIZE) - end = PGDIR_SIZE; - if (address >= end) - BUG(); - do { - unuse_pmd(vma, pmd, address, end - address, offset, entry, - page); - address = (address + PMD_SIZE) & PMD_MASK; - pmd++; - } while (address && (address < end)); -} - -/* mmlist_lock and vma->vm_mm->page_table_lock are held */ -static void unuse_vma(struct vm_area_struct * vma, pgd_t *pgdir, - swp_entry_t entry, struct page* page) -{ - unsigned long start = vma->vm_start, end = vma->vm_end; - - if (start >= end) - BUG(); - do { - unuse_pgd(vma, pgdir, start, end - start, entry, page); - start = (start + PGDIR_SIZE) & PGDIR_MASK; - pgdir++; - } while (start && (start < end)); -} - -static void unuse_process(struct mm_struct * mm, - swp_entry_t entry, struct page* page) -{ - struct vm_area_struct* vma; - - /* - * Go through process' page directory. - */ - spin_lock(&mm->page_table_lock); - for (vma = mm->mmap; vma; vma = vma->vm_next) { - pgd_t * pgd = pgd_offset(mm, vma->vm_start); - unuse_vma(vma, pgd, entry, page); - } - XENO_flush_page_update_queue(); - spin_unlock(&mm->page_table_lock); - return; -} - -/* - * Scan swap_map from current position to next entry still in use. - * Recycle to start on reaching the end, returning 0 when empty. - */ -static int find_next_to_unuse(struct swap_info_struct *si, int prev) -{ - int max = si->max; - int i = prev; - int count; - - /* - * No need for swap_device_lock(si) here: we're just looking - * for whether an entry is in use, not modifying it; false - * hits are okay, and sys_swapoff() has already prevented new - * allocations from this area (while holding swap_list_lock()). - */ - for (;;) { - if (++i >= max) { - if (!prev) { - i = 0; - break; - } - /* - * No entries in use at top of swap_map, - * loop back to start and recheck there. - */ - max = prev + 1; - prev = 0; - i = 1; - } - count = si->swap_map[i]; - if (count && count != SWAP_MAP_BAD) - break; - } - return i; -} - -/* - * We completely avoid races by reading each swap page in advance, - * and then search for the process using it. All the necessary - * page table adjustments can then be made atomically. - */ -static int try_to_unuse(unsigned int type) -{ - struct swap_info_struct * si = &swap_info[type]; - struct mm_struct *start_mm; - unsigned short *swap_map; - unsigned short swcount; - struct page *page; - swp_entry_t entry; - int i = 0; - int retval = 0; - int reset_overflow = 0; - - /* - * When searching mms for an entry, a good strategy is to - * start at the first mm we freed the previous entry from - * (though actually we don't notice whether we or coincidence - * freed the entry). Initialize this start_mm with a hold. - * - * A simpler strategy would be to start at the last mm we - * freed the previous entry from; but that would take less - * advantage of mmlist ordering (now preserved by swap_out()), - * which clusters forked address spaces together, most recent - * child immediately after parent. If we race with dup_mmap(), - * we very much want to resolve parent before child, otherwise - * we may miss some entries: using last mm would invert that. - */ - start_mm = &init_mm; - atomic_inc(&init_mm.mm_users); - - /* - * Keep on scanning until all entries have gone. Usually, - * one pass through swap_map is enough, but not necessarily: - * mmput() removes mm from mmlist before exit_mmap() and its - * zap_page_range(). That's not too bad, those entries are - * on their way out, and handled faster there than here. - * do_munmap() behaves similarly, taking the range out of mm's - * vma list before zap_page_range(). But unfortunately, when - * unmapping a part of a vma, it takes the whole out first, - * then reinserts what's left after (might even reschedule if - * open() method called) - so swap entries may be invisible - * to swapoff for a while, then reappear - but that is rare. - */ - while ((i = find_next_to_unuse(si, i))) { - /* - * Get a page for the entry, using the existing swap - * cache page if there is one. Otherwise, get a clean - * page and read the swap into it. - */ - swap_map = &si->swap_map[i]; - entry = SWP_ENTRY(type, i); - page = read_swap_cache_async(entry); - if (!page) { - /* - * Either swap_duplicate() failed because entry - * has been freed independently, and will not be - * reused since sys_swapoff() already disabled - * allocation from here, or alloc_page() failed. - */ - if (!*swap_map) - continue; - retval = -ENOMEM; - break; - } - - /* - * Don't hold on to start_mm if it looks like exiting. - */ - if (atomic_read(&start_mm->mm_users) == 1) { - mmput(start_mm); - start_mm = &init_mm; - atomic_inc(&init_mm.mm_users); - } - - /* - * Wait for and lock page. When do_swap_page races with - * try_to_unuse, do_swap_page can handle the fault much - * faster than try_to_unuse can locate the entry. This - * apparently redundant "wait_on_page" lets try_to_unuse - * defer to do_swap_page in such a case - in some tests, - * do_swap_page and try_to_unuse repeatedly compete. - */ - wait_on_page(page); - lock_page(page); - - /* - * Remove all references to entry, without blocking. - * Whenever we reach init_mm, there's no address space - * to search, but use it as a reminder to search shmem. - */ - swcount = *swap_map; - if (swcount > 1) { - flush_page_to_ram(page); - if (start_mm == &init_mm) - shmem_unuse(entry, page); - else - unuse_process(start_mm, entry, page); - } - if (*swap_map > 1) { - int set_start_mm = (*swap_map >= swcount); - struct list_head *p = &start_mm->mmlist; - struct mm_struct *new_start_mm = start_mm; - struct mm_struct *mm; - - spin_lock(&mmlist_lock); - while (*swap_map > 1 && - (p = p->next) != &start_mm->mmlist) { - mm = list_entry(p, struct mm_struct, mmlist); - swcount = *swap_map; - if (mm == &init_mm) { - set_start_mm = 1; - shmem_unuse(entry, page); - } else - unuse_process(mm, entry, page); - if (set_start_mm && *swap_map < swcount) { - new_start_mm = mm; - set_start_mm = 0; - } - } - atomic_inc(&new_start_mm->mm_users); - spin_unlock(&mmlist_lock); - mmput(start_mm); - start_mm = new_start_mm; - } - - /* - * How could swap count reach 0x7fff when the maximum - * pid is 0x7fff, and there's no way to repeat a swap - * page within an mm (except in shmem, where it's the - * shared object which takes the reference count)? - * We believe SWAP_MAP_MAX cannot occur in Linux 2.4. - * - * If that's wrong, then we should worry more about - * exit_mmap() and do_munmap() cases described above: - * we might be resetting SWAP_MAP_MAX too early here. - * We know "Undead"s can happen, they're okay, so don't - * report them; but do report if we reset SWAP_MAP_MAX. - */ - if (*swap_map == SWAP_MAP_MAX) { - swap_list_lock(); - swap_device_lock(si); - nr_swap_pages++; - *swap_map = 1; - swap_device_unlock(si); - swap_list_unlock(); - reset_overflow = 1; - } - - /* - * If a reference remains (rare), we would like to leave - * the page in the swap cache; but try_to_swap_out could - * then re-duplicate the entry once we drop page lock, - * so we might loop indefinitely; also, that page could - * not be swapped out to other storage meanwhile. So: - * delete from cache even if there's another reference, - * after ensuring that the data has been saved to disk - - * since if the reference remains (rarer), it will be - * read from disk into another page. Splitting into two - * pages would be incorrect if swap supported "shared - * private" pages, but they are handled by tmpfs files. - * Note shmem_unuse already deleted its from swap cache. - */ - swcount = *swap_map; - if ((swcount > 0) != PageSwapCache(page)) - BUG(); - if ((swcount > 1) && PageDirty(page)) { - rw_swap_page(WRITE, page); - lock_page(page); - } - if (PageSwapCache(page)) - delete_from_swap_cache(page); - - /* - * So we could skip searching mms once swap count went - * to 1, we did not mark any present ptes as dirty: must - * mark page dirty so try_to_swap_out will preserve it. - */ - SetPageDirty(page); - UnlockPage(page); - page_cache_release(page); - - /* - * Make sure that we aren't completely killing - * interactive performance. Interruptible check on - * signal_pending() would be nice, but changes the spec? - */ - if (current->need_resched) - schedule(); - } - - mmput(start_mm); - if (reset_overflow) { - printk(KERN_WARNING "swapoff: cleared swap entry overflow\n"); - swap_overflow = 0; - } - return retval; -} - -asmlinkage long sys_swapoff(const char * specialfile) -{ - struct swap_info_struct * p = NULL; - unsigned short *swap_map; - struct nameidata nd; - int i, type, prev; - int err; - - if (!capable(CAP_SYS_ADMIN)) - return -EPERM; - - err = user_path_walk(specialfile, &nd); - if (err) - goto out; - - lock_kernel(); - prev = -1; - swap_list_lock(); - for (type = swap_list.head; type >= 0; type = swap_info[type].next) { - p = swap_info + type; - if ((p->flags & SWP_WRITEOK) == SWP_WRITEOK) { - if (p->swap_file == nd.dentry) - break; - } - prev = type; - } - err = -EINVAL; - if (type < 0) { - swap_list_unlock(); - goto out_dput; - } - - if (prev < 0) { - swap_list.head = p->next; - } else { - swap_info[prev].next = p->next; - } - if (type == swap_list.next) { - /* just pick something that's safe... */ - swap_list.next = swap_list.head; - } - nr_swap_pages -= p->pages; - total_swap_pages -= p->pages; - p->flags = SWP_USED; - swap_list_unlock(); - unlock_kernel(); - err = try_to_unuse(type); - lock_kernel(); - if (err) { - /* re-insert swap space back into swap_list */ - swap_list_lock(); - for (prev = -1, i = swap_list.head; i >= 0; prev = i, i = swap_info[i].next) - if (p->prio >= swap_info[i].prio) - break; - p->next = i; - if (prev < 0) - swap_list.head = swap_list.next = p - swap_info; - else - swap_info[prev].next = p - swap_info; - nr_swap_pages += p->pages; - total_swap_pages += p->pages; - p->flags = SWP_WRITEOK; - swap_list_unlock(); - goto out_dput; - } - if (p->swap_device) - blkdev_put(p->swap_file->d_inode->i_bdev, BDEV_SWAP); - path_release(&nd); - - swap_list_lock(); - swap_device_lock(p); - nd.mnt = p->swap_vfsmnt; - nd.dentry = p->swap_file; - p->swap_vfsmnt = NULL; - p->swap_file = NULL; - p->swap_device = 0; - p->max = 0; - swap_map = p->swap_map; - p->swap_map = NULL; - p->flags = 0; - swap_device_unlock(p); - swap_list_unlock(); - vfree(swap_map); - err = 0; - -out_dput: - unlock_kernel(); - path_release(&nd); -out: - return err; -} - -int get_swaparea_info(char *buf) -{ - char * page = (char *) __get_free_page(GFP_KERNEL); - struct swap_info_struct *ptr = swap_info; - int i, j, len = 0, usedswap; - - if (!page) - return -ENOMEM; - - len += sprintf(buf, "Filename\t\t\tType\t\tSize\tUsed\tPriority\n"); - for (i = 0 ; i < nr_swapfiles ; i++, ptr++) { - if ((ptr->flags & SWP_USED) && ptr->swap_map) { - char * path = d_path(ptr->swap_file, ptr->swap_vfsmnt, - page, PAGE_SIZE); - - len += sprintf(buf + len, "%-31s ", path); - - if (!ptr->swap_device) - len += sprintf(buf + len, "file\t\t"); - else - len += sprintf(buf + len, "partition\t"); - - usedswap = 0; - for (j = 0; j < ptr->max; ++j) - switch (ptr->swap_map[j]) { - case SWAP_MAP_BAD: - case 0: - continue; - default: - usedswap++; - } - len += sprintf(buf + len, "%d\t%d\t%d\n", ptr->pages << (PAGE_SHIFT - 10), - usedswap << (PAGE_SHIFT - 10), ptr->prio); - } - } - free_page((unsigned long) page); - return len; -} - -int is_swap_partition(kdev_t dev) { - struct swap_info_struct *ptr = swap_info; - int i; - - for (i = 0 ; i < nr_swapfiles ; i++, ptr++) { - if (ptr->flags & SWP_USED) - if (ptr->swap_device == dev) - return 1; - } - return 0; -} - -/* - * Written 01/25/92 by Simmule Turner, heavily changed by Linus. - * - * The swapon system call - */ -asmlinkage long sys_swapon(const char * specialfile, int swap_flags) -{ - struct swap_info_struct * p; - struct nameidata nd; - struct inode * swap_inode; - unsigned int type; - int i, j, prev; - int error; - static int least_priority = 0; - union swap_header *swap_header = 0; - int swap_header_version; - int nr_good_pages = 0; - unsigned long maxpages = 1; - int swapfilesize; - struct block_device *bdev = NULL; - unsigned short *swap_map; - - if (!capable(CAP_SYS_ADMIN)) - return -EPERM; - lock_kernel(); - swap_list_lock(); - p = swap_info; - for (type = 0 ; type < nr_swapfiles ; type++,p++) - if (!(p->flags & SWP_USED)) - break; - error = -EPERM; - if (type >= MAX_SWAPFILES) { - swap_list_unlock(); - goto out; - } - if (type >= nr_swapfiles) - nr_swapfiles = type+1; - p->flags = SWP_USED; - p->swap_file = NULL; - p->swap_vfsmnt = NULL; - p->swap_device = 0; - p->swap_map = NULL; - p->lowest_bit = 0; - p->highest_bit = 0; - p->cluster_nr = 0; - p->sdev_lock = SPIN_LOCK_UNLOCKED; - p->next = -1; - if (swap_flags & SWAP_FLAG_PREFER) { - p->prio = - (swap_flags & SWAP_FLAG_PRIO_MASK)>>SWAP_FLAG_PRIO_SHIFT; - } else { - p->prio = --least_priority; - } - swap_list_unlock(); - error = user_path_walk(specialfile, &nd); - if (error) - goto bad_swap_2; - - p->swap_file = nd.dentry; - p->swap_vfsmnt = nd.mnt; - swap_inode = nd.dentry->d_inode; - error = -EINVAL; - - if (S_ISBLK(swap_inode->i_mode)) { - kdev_t dev = swap_inode->i_rdev; - struct block_device_operations *bdops; - - p->swap_device = dev; - set_blocksize(dev, PAGE_SIZE); - - bd_acquire(swap_inode); - bdev = swap_inode->i_bdev; - bdops = devfs_get_ops(devfs_get_handle_from_inode(swap_inode)); - if (bdops) bdev->bd_op = bdops; - - error = blkdev_get(bdev, FMODE_READ|FMODE_WRITE, 0, BDEV_SWAP); - if (error) - goto bad_swap_2; - set_blocksize(dev, PAGE_SIZE); - error = -ENODEV; - if (!dev || (blk_size[MAJOR(dev)] && - !blk_size[MAJOR(dev)][MINOR(dev)])) - goto bad_swap; - swapfilesize = 0; - if (blk_size[MAJOR(dev)]) - swapfilesize = blk_size[MAJOR(dev)][MINOR(dev)] - >> (PAGE_SHIFT - 10); - } else if (S_ISREG(swap_inode->i_mode)) - swapfilesize = swap_inode->i_size >> PAGE_SHIFT; - else - goto bad_swap; - - error = -EBUSY; - for (i = 0 ; i < nr_swapfiles ; i++) { - struct swap_info_struct *q = &swap_info[i]; - if (i == type || !q->swap_file) - continue; - if (swap_inode->i_mapping == q->swap_file->d_inode->i_mapping) - goto bad_swap; - } - - swap_header = (void *) __get_free_page(GFP_USER); - if (!swap_header) { - printk("Unable to start swapping: out of memory :-)\n"); - error = -ENOMEM; - goto bad_swap; - } - - lock_page(virt_to_page(swap_header)); - rw_swap_page_nolock(READ, SWP_ENTRY(type,0), (char *) swap_header); - - if (!memcmp("SWAP-SPACE",swap_header->magic.magic,10)) - swap_header_version = 1; - else if (!memcmp("SWAPSPACE2",swap_header->magic.magic,10)) - swap_header_version = 2; - else { - printk("Unable to find swap-space signature\n"); - error = -EINVAL; - goto bad_swap; - } - - switch (swap_header_version) { - case 1: - memset(((char *) swap_header)+PAGE_SIZE-10,0,10); - j = 0; - p->lowest_bit = 0; - p->highest_bit = 0; - for (i = 1 ; i < 8*PAGE_SIZE ; i++) { - if (test_bit(i,(char *) swap_header)) { - if (!p->lowest_bit) - p->lowest_bit = i; - p->highest_bit = i; - maxpages = i+1; - j++; - } - } - nr_good_pages = j; - p->swap_map = vmalloc(maxpages * sizeof(short)); - if (!p->swap_map) { - error = -ENOMEM; - goto bad_swap; - } - for (i = 1 ; i < maxpages ; i++) { - if (test_bit(i,(char *) swap_header)) - p->swap_map[i] = 0; - else - p->swap_map[i] = SWAP_MAP_BAD; - } - break; - - case 2: - /* Check the swap header's sub-version and the size of - the swap file and bad block lists */ - if (swap_header->info.version != 1) { - printk(KERN_WARNING - "Unable to handle swap header version %d\n", - swap_header->info.version); - error = -EINVAL; - goto bad_swap; - } - - p->lowest_bit = 1; - maxpages = SWP_OFFSET(SWP_ENTRY(0,~0UL)) - 1; - if (maxpages > swap_header->info.last_page) - maxpages = swap_header->info.last_page; - p->highest_bit = maxpages - 1; - - error = -EINVAL; - if (swap_header->info.nr_badpages > MAX_SWAP_BADPAGES) - goto bad_swap; - - /* OK, set up the swap map and apply the bad block list */ - if (!(p->swap_map = vmalloc(maxpages * sizeof(short)))) { - error = -ENOMEM; - goto bad_swap; - } - - error = 0; - memset(p->swap_map, 0, maxpages * sizeof(short)); - for (i=0; i<swap_header->info.nr_badpages; i++) { - int page = swap_header->info.badpages[i]; - if (page <= 0 || page >= swap_header->info.last_page) - error = -EINVAL; - else - p->swap_map[page] = SWAP_MAP_BAD; - } - nr_good_pages = swap_header->info.last_page - - swap_header->info.nr_badpages - - 1 /* header page */; - if (error) - goto bad_swap; - } - - if (swapfilesize && maxpages > swapfilesize) { - printk(KERN_WARNING - "Swap area shorter than signature indicates\n"); - error = -EINVAL; - goto bad_swap; - } - if (!nr_good_pages) { - printk(KERN_WARNING "Empty swap-file\n"); - error = -EINVAL; - goto bad_swap; - } - p->swap_map[0] = SWAP_MAP_BAD; - swap_list_lock(); - swap_device_lock(p); - p->max = maxpages; - p->flags = SWP_WRITEOK; - p->pages = nr_good_pages; - nr_swap_pages += nr_good_pages; - total_swap_pages += nr_good_pages; - printk(KERN_INFO "Adding Swap: %dk swap-space (priority %d)\n", - nr_good_pages<<(PAGE_SHIFT-10), p->prio); - - /* insert swap space into swap_list: */ - prev = -1; - for (i = swap_list.head; i >= 0; i = swap_info[i].next) { - if (p->prio >= swap_info[i].prio) { - break; - } - prev = i; - } - p->next = i; - if (prev < 0) { - swap_list.head = swap_list.next = p - swap_info; - } else { - swap_info[prev].next = p - swap_info; - } - swap_device_unlock(p); - swap_list_unlock(); - error = 0; - goto out; -bad_swap: - if (bdev) - blkdev_put(bdev, BDEV_SWAP); -bad_swap_2: - swap_list_lock(); - swap_map = p->swap_map; - nd.mnt = p->swap_vfsmnt; - nd.dentry = p->swap_file; - p->swap_device = 0; - p->swap_file = NULL; - p->swap_vfsmnt = NULL; - p->swap_map = NULL; - p->flags = 0; - if (!(swap_flags & SWAP_FLAG_PREFER)) - ++least_priority; - swap_list_unlock(); - if (swap_map) - vfree(swap_map); - path_release(&nd); -out: - if (swap_header) - free_page((long) swap_header); - unlock_kernel(); - return error; -} - -void si_swapinfo(struct sysinfo *val) -{ - unsigned int i; - unsigned long nr_to_be_unused = 0; - - swap_list_lock(); - for (i = 0; i < nr_swapfiles; i++) { - unsigned int j; - if (swap_info[i].flags != SWP_USED) - continue; - for (j = 0; j < swap_info[i].max; ++j) { - switch (swap_info[i].swap_map[j]) { - case 0: - case SWAP_MAP_BAD: - continue; - default: - nr_to_be_unused++; - } - } - } - val->freeswap = nr_swap_pages + nr_to_be_unused; - val->totalswap = total_swap_pages + nr_to_be_unused; - swap_list_unlock(); -} - -/* - * Verify that a swap entry is valid and increment its swap map count. - * - * Note: if swap_map[] reaches SWAP_MAP_MAX the entries are treated as - * "permanent", but will be reclaimed by the next swapoff. - */ -int swap_duplicate(swp_entry_t entry) -{ - struct swap_info_struct * p; - unsigned long offset, type; - int result = 0; - - type = SWP_TYPE(entry); - if (type >= nr_swapfiles) - goto bad_file; - p = type + swap_info; - offset = SWP_OFFSET(entry); - - swap_device_lock(p); - if (offset < p->max && p->swap_map[offset]) { - if (p->swap_map[offset] < SWAP_MAP_MAX - 1) { - p->swap_map[offset]++; - result = 1; - } else if (p->swap_map[offset] <= SWAP_MAP_MAX) { - if (swap_overflow++ < 5) - printk(KERN_WARNING "swap_dup: swap entry overflow\n"); - p->swap_map[offset] = SWAP_MAP_MAX; - result = 1; - } - } - swap_device_unlock(p); -out: - return result; - -bad_file: - printk(KERN_ERR "swap_dup: %s%08lx\n", Bad_file, entry.val); - goto out; -} - -/* - * Page lock needs to be held in all cases to prevent races with - * swap file deletion. - */ -int swap_count(struct page *page) -{ - struct swap_info_struct * p; - unsigned long offset, type; - swp_entry_t entry; - int retval = 0; - - entry.val = page->index; - if (!entry.val) - goto bad_entry; - type = SWP_TYPE(entry); - if (type >= nr_swapfiles) - goto bad_file; - p = type + swap_info; - offset = SWP_OFFSET(entry); - if (offset >= p->max) - goto bad_offset; - if (!p->swap_map[offset]) - goto bad_unused; - retval = p->swap_map[offset]; -out: - return retval; - -bad_entry: - printk(KERN_ERR "swap_count: null entry!\n"); - goto out; -bad_file: - printk(KERN_ERR "swap_count: %s%08lx\n", Bad_file, entry.val); - goto out; -bad_offset: - printk(KERN_ERR "swap_count: %s%08lx\n", Bad_offset, entry.val); - goto out; -bad_unused: - printk(KERN_ERR "swap_count: %s%08lx\n", Unused_offset, entry.val); - goto out; -} - -/* - * Prior swap_duplicate protects against swap device deletion. - */ -void get_swaphandle_info(swp_entry_t entry, unsigned long *offset, - kdev_t *dev, struct inode **swapf) -{ - unsigned long type; - struct swap_info_struct *p; - - type = SWP_TYPE(entry); - if (type >= nr_swapfiles) { - printk(KERN_ERR "rw_swap_page: %s%08lx\n", Bad_file, entry.val); - return; - } - - p = &swap_info[type]; - *offset = SWP_OFFSET(entry); - if (*offset >= p->max && *offset != 0) { - printk(KERN_ERR "rw_swap_page: %s%08lx\n", Bad_offset, entry.val); - return; - } - if (p->swap_map && !p->swap_map[*offset]) { - printk(KERN_ERR "rw_swap_page: %s%08lx\n", Unused_offset, entry.val); - return; - } - if (!(p->flags & SWP_USED)) { - printk(KERN_ERR "rw_swap_page: %s%08lx\n", Unused_file, entry.val); - return; - } - - if (p->swap_device) { - *dev = p->swap_device; - } else if (p->swap_file) { - *swapf = p->swap_file->d_inode; - } else { - printk(KERN_ERR "rw_swap_page: no swap file or device\n"); - } - return; -} - -/* - * swap_device_lock prevents swap_map being freed. Don't grab an extra - * reference on the swaphandle, it doesn't matter if it becomes unused. - */ -int valid_swaphandles(swp_entry_t entry, unsigned long *offset) -{ - int ret = 0, i = 1 << page_cluster; - unsigned long toff; - struct swap_info_struct *swapdev = SWP_TYPE(entry) + swap_info; - - if (!page_cluster) /* no readahead */ - return 0; - toff = (SWP_OFFSET(entry) >> page_cluster) << page_cluster; - if (!toff) /* first page is swap header */ - toff++, i--; - *offset = toff; - - swap_device_lock(swapdev); - do { - /* Don't read-ahead past the end of the swap area */ - if (toff >= swapdev->max) - break; - /* Don't read in free or bad pages */ - if (!swapdev->swap_map[toff]) - break; - if (swapdev->swap_map[toff] == SWAP_MAP_BAD) - break; - toff++; - ret++; - } while (--i); - swap_device_unlock(swapdev); - return ret; -} |