X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=mm%2Fswapfile.c;h=90cb67a5417cccea9f0352b6316f747bec4c608d;hb=d72b37513cdfbd3f53f3d485a8c403cc96d2c95f;hp=eade24da9310d4cc4e7499e5580d52fbb929701c;hpb=f315ccb3e679f271583f2a4f463ad9b65665b751;p=linux-2.6-omap-h63xx.git diff --git a/mm/swapfile.c b/mm/swapfile.c index eade24da931..90cb67a5417 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -27,22 +27,24 @@ #include #include #include +#include #include #include #include -DEFINE_SPINLOCK(swap_lock); -unsigned int nr_swapfiles; +static DEFINE_SPINLOCK(swap_lock); +static unsigned int nr_swapfiles; long total_swap_pages; static int swap_overflow; +static int least_priority; 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}; +static struct swap_list_t swap_list = {-1, -1}; static struct swap_info_struct swap_info[MAX_SWAPFILES]; @@ -342,7 +344,7 @@ int can_share_swap_page(struct page *page) * 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) +static int remove_exclusive_swap_page_count(struct page *page, int count) { int retval; struct swap_info_struct * p; @@ -355,7 +357,7 @@ int remove_exclusive_swap_page(struct page *page) return 0; if (PageWriteback(page)) return 0; - if (page_count(page) != 2) /* 2: us + cache */ + if (page_count(page) != count) /* us + cache + ptes */ return 0; entry.val = page_private(page); @@ -367,13 +369,13 @@ int remove_exclusive_swap_page(struct page *page) retval = 0; if (p->swap_map[swp_offset(entry)] == 1) { /* Recheck the page count with the swapcache lock held.. */ - write_lock_irq(&swapper_space.tree_lock); - if ((page_count(page) == 2) && !PageWriteback(page)) { + spin_lock_irq(&swapper_space.tree_lock); + if ((page_count(page) == count) && !PageWriteback(page)) { __delete_from_swap_cache(page); SetPageDirty(page); retval = 1; } - write_unlock_irq(&swapper_space.tree_lock); + spin_unlock_irq(&swapper_space.tree_lock); } spin_unlock(&swap_lock); @@ -385,6 +387,25 @@ int remove_exclusive_swap_page(struct page *page) return retval; } +/* + * Most of the time the page should have two references: one for the + * process and one for the swap cache. + */ +int remove_exclusive_swap_page(struct page *page) +{ + return remove_exclusive_swap_page_count(page, 2); +} + +/* + * The pageout code holds an extra reference to the page. That raises + * the reference count to test for to 2 for a page that is only in the + * swap cache plus 1 for each process that maps the page. + */ +int remove_exclusive_swap_page_ref(struct page *page) +{ + return remove_exclusive_swap_page_count(page, 2 + page_mapcount(page)); +} + /* * Free the swap entry like above, but also try to * free the page cache entry if it is the last user. @@ -401,7 +422,7 @@ void free_swap_and_cache(swp_entry_t entry) if (p) { if (swap_entry_free(p, swp_offset(entry)) == 1) { page = find_get_page(&swapper_space, entry.val); - if (page && unlikely(TestSetPageLocked(page))) { + if (page && !trylock_page(page)) { page_cache_release(page); page = NULL; } @@ -511,11 +532,16 @@ static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd, { spinlock_t *ptl; pte_t *pte; - int found = 1; + int ret = 1; + + if (mem_cgroup_charge(page, vma->vm_mm, GFP_KERNEL)) + ret = -ENOMEM; pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); if (unlikely(!pte_same(*pte, swp_entry_to_pte(entry)))) { - found = 0; + if (ret > 0) + mem_cgroup_uncharge_page(page); + ret = 0; goto out; } @@ -532,7 +558,7 @@ static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd, activate_page(page); out: pte_unmap_unlock(pte, ptl); - return found; + return ret; } static int unuse_pte_range(struct vm_area_struct *vma, pmd_t *pmd, @@ -541,7 +567,7 @@ static int unuse_pte_range(struct vm_area_struct *vma, pmd_t *pmd, { pte_t swp_pte = swp_entry_to_pte(entry); pte_t *pte; - int found = 0; + int ret = 0; /* * We don't actually need pte lock while scanning for swp_pte: since @@ -560,15 +586,15 @@ static int unuse_pte_range(struct vm_area_struct *vma, pmd_t *pmd, */ if (unlikely(pte_same(*pte, swp_pte))) { pte_unmap(pte); - found = unuse_pte(vma, pmd, addr, entry, page); - if (found) + ret = unuse_pte(vma, pmd, addr, entry, page); + if (ret) goto out; pte = pte_offset_map(pmd, addr); } } while (pte++, addr += PAGE_SIZE, addr != end); pte_unmap(pte - 1); out: - return found; + return ret; } static inline int unuse_pmd_range(struct vm_area_struct *vma, pud_t *pud, @@ -577,14 +603,16 @@ static inline int unuse_pmd_range(struct vm_area_struct *vma, pud_t *pud, { pmd_t *pmd; unsigned long next; + int ret; pmd = pmd_offset(pud, addr); do { next = pmd_addr_end(addr, end); if (pmd_none_or_clear_bad(pmd)) continue; - if (unuse_pte_range(vma, pmd, addr, next, entry, page)) - return 1; + ret = unuse_pte_range(vma, pmd, addr, next, entry, page); + if (ret) + return ret; } while (pmd++, addr = next, addr != end); return 0; } @@ -595,14 +623,16 @@ static inline int unuse_pud_range(struct vm_area_struct *vma, pgd_t *pgd, { pud_t *pud; unsigned long next; + int ret; pud = pud_offset(pgd, addr); do { next = pud_addr_end(addr, end); if (pud_none_or_clear_bad(pud)) continue; - if (unuse_pmd_range(vma, pud, addr, next, entry, page)) - return 1; + ret = unuse_pmd_range(vma, pud, addr, next, entry, page); + if (ret) + return ret; } while (pud++, addr = next, addr != end); return 0; } @@ -612,6 +642,7 @@ static int unuse_vma(struct vm_area_struct *vma, { pgd_t *pgd; unsigned long addr, end, next; + int ret; if (page->mapping) { addr = page_address_in_vma(page, vma); @@ -629,8 +660,9 @@ static int unuse_vma(struct vm_area_struct *vma, next = pgd_addr_end(addr, end); if (pgd_none_or_clear_bad(pgd)) continue; - if (unuse_pud_range(vma, pgd, addr, next, entry, page)) - return 1; + ret = unuse_pud_range(vma, pgd, addr, next, entry, page); + if (ret) + return ret; } while (pgd++, addr = next, addr != end); return 0; } @@ -639,11 +671,12 @@ static int unuse_mm(struct mm_struct *mm, swp_entry_t entry, struct page *page) { struct vm_area_struct *vma; + int ret = 0; if (!down_read_trylock(&mm->mmap_sem)) { /* - * Activate page so shrink_cache is unlikely to unmap its - * ptes while lock is dropped, so swapoff can make progress. + * Activate page so shrink_inactive_list is unlikely to unmap + * its ptes while lock is dropped, so swapoff can make progress. */ activate_page(page); unlock_page(page); @@ -651,15 +684,11 @@ static int unuse_mm(struct mm_struct *mm, lock_page(page); } for (vma = mm->mmap; vma; vma = vma->vm_next) { - if (vma->anon_vma && unuse_vma(vma, entry, page)) + if (vma->anon_vma && (ret = unuse_vma(vma, entry, page))) break; } up_read(&mm->mmap_sem); - /* - * Currently unuse_mm cannot fail, but leave error handling - * at call sites for now, since we change it from time to time. - */ - return 0; + return (ret < 0)? ret: 0; } /* @@ -1251,6 +1280,11 @@ asmlinkage long sys_swapoff(const char __user * specialfile) /* just pick something that's safe... */ swap_list.next = swap_list.head; } + if (p->prio < 0) { + for (i = p->next; i >= 0; i = swap_info[i].next) + swap_info[i].prio = p->prio--; + least_priority++; + } nr_swap_pages -= p->pages; total_swap_pages -= p->pages; p->flags &= ~SWP_WRITEOK; @@ -1263,9 +1297,14 @@ asmlinkage long sys_swapoff(const char __user * specialfile) if (err) { /* re-insert swap space back into swap_list */ spin_lock(&swap_lock); - for (prev = -1, i = swap_list.head; i >= 0; prev = i, i = swap_info[i].next) + if (p->prio < 0) + p->prio = --least_priority; + 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; @@ -1385,7 +1424,7 @@ static int swap_show(struct seq_file *swap, void *v) } file = ptr->swap_file; - len = seq_path(swap, file->f_path.mnt, file->f_path.dentry, " \t\n\\"); + len = seq_path(swap, &file->f_path, " \t\n\\"); seq_printf(swap, "%*s%s\t%u\t%u\t%d\n", len < 40 ? 40 - len : 1, " ", S_ISBLK(file->f_path.dentry->d_inode->i_mode) ? @@ -1417,11 +1456,7 @@ static const struct file_operations proc_swaps_operations = { static int __init procswaps_init(void) { - struct proc_dir_entry *entry; - - entry = create_proc_entry("swaps", 0, NULL); - if (entry) - entry->proc_fops = &proc_swaps_operations; + proc_create("swaps", 0, NULL, &proc_swaps_operations); return 0; } __initcall(procswaps_init); @@ -1442,7 +1477,6 @@ asmlinkage long sys_swapon(const char __user * specialfile, int swap_flags) unsigned int type; int i, prev; int error; - static int least_priority; union swap_header *swap_header = NULL; int swap_header_version; unsigned int nr_good_pages = 0; @@ -1450,7 +1484,7 @@ asmlinkage long sys_swapon(const char __user * specialfile, int swap_flags) sector_t span; unsigned long maxpages = 1; int swapfilesize; - unsigned short *swap_map; + unsigned short *swap_map = NULL; struct page *page = NULL; struct inode *inode = NULL; int did_down = 0; @@ -1469,22 +1503,10 @@ asmlinkage long sys_swapon(const char __user * specialfile, int swap_flags) } if (type >= nr_swapfiles) nr_swapfiles = type+1; + memset(p, 0, sizeof(*p)); INIT_LIST_HEAD(&p->extent_list); p->flags = SWP_USED; - p->swap_file = NULL; - p->old_block_size = 0; - p->swap_map = NULL; - p->lowest_bit = 0; - p->highest_bit = 0; - p->cluster_nr = 0; - p->inuse_pages = 0; 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; - } spin_unlock(&swap_lock); name = getname(specialfile); error = PTR_ERR(name); @@ -1573,6 +1595,14 @@ asmlinkage long sys_swapon(const char __user * specialfile, int swap_flags) error = -EINVAL; goto bad_swap; case 2: + /* swap partition endianess hack... */ + if (swab32(swap_header->info.version) == 1) { + swab32s(&swap_header->info.version); + swab32s(&swap_header->info.last_page); + swab32s(&swap_header->info.nr_badpages); + for (i = 0; i < swap_header->info.nr_badpages; i++) + swab32s(&swap_header->info.badpages[i]); + } /* Check the swap header's sub-version and the size of the swap file and bad block lists */ if (swap_header->info.version != 1) { @@ -1619,19 +1649,20 @@ asmlinkage long sys_swapon(const char __user * specialfile, int swap_flags) goto bad_swap; /* OK, set up the swap map and apply the bad block list */ - if (!(p->swap_map = vmalloc(maxpages * sizeof(short)))) { + swap_map = vmalloc(maxpages * sizeof(short)); + if (!swap_map) { error = -ENOMEM; goto bad_swap; } error = 0; - memset(p->swap_map, 0, maxpages * sizeof(short)); + memset(swap_map, 0, maxpages * sizeof(short)); for (i = 0; i < swap_header->info.nr_badpages; i++) { int page_nr = swap_header->info.badpages[i]; if (page_nr <= 0 || page_nr >= swap_header->info.last_page) error = -EINVAL; else - p->swap_map[page_nr] = SWAP_MAP_BAD; + swap_map[page_nr] = SWAP_MAP_BAD; } nr_good_pages = swap_header->info.last_page - swap_header->info.nr_badpages - @@ -1641,7 +1672,7 @@ asmlinkage long sys_swapon(const char __user * specialfile, int swap_flags) } if (nr_good_pages) { - p->swap_map[0] = SWAP_MAP_BAD; + swap_map[0] = SWAP_MAP_BAD; p->max = maxpages; p->pages = nr_good_pages; nr_extents = setup_swap_extents(p, &span); @@ -1659,6 +1690,12 @@ asmlinkage long sys_swapon(const char __user * specialfile, int swap_flags) mutex_lock(&swapon_mutex); spin_lock(&swap_lock); + if (swap_flags & SWAP_FLAG_PREFER) + p->prio = + (swap_flags & SWAP_FLAG_PRIO_MASK) >> SWAP_FLAG_PRIO_SHIFT; + else + p->prio = --least_priority; + p->swap_map = swap_map; p->flags = SWP_ACTIVE; nr_swap_pages += nr_good_pages; total_swap_pages += nr_good_pages; @@ -1694,12 +1731,8 @@ bad_swap: destroy_swap_extents(p); bad_swap_2: spin_lock(&swap_lock); - swap_map = p->swap_map; p->swap_file = NULL; - p->swap_map = NULL; p->flags = 0; - if (!(swap_flags & SWAP_FLAG_PREFER)) - ++least_priority; spin_unlock(&swap_lock); vfree(swap_map); if (swap_file)