X-Git-Url: http://pilppa.org/gitweb/?a=blobdiff_plain;f=mm%2Fswapfile.c;h=f1f5ec783781cfebcbd4f3c5efe79336eaedcfa1;hb=a302eb4e4602d6444ae75a0e516fb2f2c62d6642;hp=957fef43fa6081ec62cf3459e3b5db2d865eae57;hpb=593195f9b2309693f27b402f34573f7920b82c3e;p=linux-2.6-omap-h63xx.git diff --git a/mm/swapfile.c b/mm/swapfile.c index 957fef43fa6..f1f5ec78378 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -5,7 +5,6 @@ * Swap reorganised 29.12.95, Stephen Tweedie */ -#include #include #include #include @@ -25,6 +24,7 @@ #include #include #include +#include #include #include @@ -44,14 +44,14 @@ 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]; +static struct swap_info_struct swap_info[MAX_SWAPFILES]; -static DECLARE_MUTEX(swapon_sem); +static DEFINE_MUTEX(swapon_mutex); /* * We need this because the bdev->unplug_fn can sleep and we cannot * hold swap_lock while calling the unplug_fn. And swap_lock - * cannot be turned into a semaphore. + * cannot be turned into a mutex. */ static DECLARE_RWSEM(swap_unplug_sem); @@ -115,7 +115,7 @@ static inline unsigned long scan_swap_map(struct swap_info_struct *si) last_in_cluster = offset + SWAPFILE_CLUSTER; else if (offset == last_in_cluster) { spin_lock(&swap_lock); - si->cluster_next = offset-SWAPFILE_CLUSTER-1; + si->cluster_next = offset-SWAPFILE_CLUSTER+1; goto cluster; } if (unlikely(--latency_ration < 0)) { @@ -394,20 +394,29 @@ void free_swap_and_cache(swp_entry_t entry) struct swap_info_struct * p; struct page *page = NULL; + if (is_migration_entry(entry)) + return; + p = swap_info_get(entry); if (p) { - if (swap_entry_free(p, swp_offset(entry)) == 1) - page = find_trylock_page(&swapper_space, entry.val); + if (swap_entry_free(p, swp_offset(entry)) == 1) { + page = find_get_page(&swapper_space, entry.val); + if (page && unlikely(TestSetPageLocked(page))) { + page_cache_release(page); + page = NULL; + } + } spin_unlock(&swap_lock); } if (page) { int one_user; BUG_ON(PagePrivate(page)); - page_cache_get(page); one_user = (page_count(page) == 2); /* Only cache user (+us), or swap space full? Free it! */ - if (!PageWriteback(page) && (one_user || vm_swap_full())) { + /* Also recheck PageSwapCache after page is locked (above) */ + if (PageSwapCache(page) && !PageWriteback(page) && + (one_user || vm_swap_full())) { delete_from_swap_cache(page); SetPageDirty(page); } @@ -416,6 +425,62 @@ void free_swap_and_cache(swp_entry_t entry) } } +#ifdef CONFIG_SOFTWARE_SUSPEND +/* + * Find the swap type that corresponds to given device (if any) + * + * This is needed for software suspend and is done in such a way that inode + * aliasing is allowed. + */ +int swap_type_of(dev_t device) +{ + int i; + + spin_lock(&swap_lock); + for (i = 0; i < nr_swapfiles; i++) { + struct inode *inode; + + if (!(swap_info[i].flags & SWP_WRITEOK)) + continue; + + if (!device) { + spin_unlock(&swap_lock); + return i; + } + inode = swap_info[i].swap_file->f_dentry->d_inode; + if (S_ISBLK(inode->i_mode) && + device == MKDEV(imajor(inode), iminor(inode))) { + spin_unlock(&swap_lock); + return i; + } + } + spin_unlock(&swap_lock); + return -ENODEV; +} + +/* + * Return either the total number of swap pages of given type, or the number + * of free pages of that type (depending on @free) + * + * This is needed for software suspend + */ +unsigned int count_swap_pages(int type, int free) +{ + unsigned int n = 0; + + if (type < nr_swapfiles) { + spin_lock(&swap_lock); + if (swap_info[type].flags & SWP_WRITEOK) { + n = swap_info[type].pages; + if (free) + n -= swap_info[type].inuse_pages; + } + spin_unlock(&swap_lock); + } + return n; +} +#endif + /* * No need to decide whether this PTE shares the swap entry with others, * just let do_wp_page work it out if a write is requested later - to @@ -707,10 +772,8 @@ static int try_to_unuse(unsigned int type) while (*swap_map > 1 && !retval && (p = p->next) != &start_mm->mmlist) { mm = list_entry(p, struct mm_struct, mmlist); - if (atomic_inc_return(&mm->mm_users) == 1) { - atomic_dec(&mm->mm_users); + if (!atomic_inc_not_zero(&mm->mm_users)) continue; - } spin_unlock(&mmlist_lock); mmput(prev_mm); prev_mm = mm; @@ -1161,7 +1224,7 @@ asmlinkage long sys_swapoff(const char __user * specialfile) up_write(&swap_unplug_sem); destroy_swap_extents(p); - down(&swapon_sem); + mutex_lock(&swapon_mutex); spin_lock(&swap_lock); drain_mmlist(); @@ -1180,7 +1243,7 @@ asmlinkage long sys_swapoff(const char __user * specialfile) p->swap_map = NULL; p->flags = 0; spin_unlock(&swap_lock); - up(&swapon_sem); + mutex_unlock(&swapon_mutex); vfree(swap_map); inode = mapping->host; if (S_ISBLK(inode->i_mode)) { @@ -1209,7 +1272,7 @@ static void *swap_start(struct seq_file *swap, loff_t *pos) int i; loff_t l = *pos; - down(&swapon_sem); + mutex_lock(&swapon_mutex); for (i = 0; i < nr_swapfiles; i++, ptr++) { if (!(ptr->flags & SWP_USED) || !ptr->swap_map) @@ -1238,7 +1301,7 @@ static void *swap_next(struct seq_file *swap, void *v, loff_t *pos) static void swap_stop(struct seq_file *swap, void *v) { - up(&swapon_sem); + mutex_unlock(&swapon_mutex); } static int swap_show(struct seq_file *swap, void *v) @@ -1329,19 +1392,7 @@ asmlinkage long sys_swapon(const char __user * specialfile, int swap_flags) if (!(p->flags & SWP_USED)) break; error = -EPERM; - /* - * Test if adding another swap device is possible. There are - * two limiting factors: 1) the number of bits for the swap - * type swp_entry_t definition and 2) the number of bits for - * the swap type in the swap ptes as defined by the different - * architectures. To honor both limitations a swap entry - * with swap offset 0 and swap type ~0UL is created, encoded - * to a swap pte, decoded to a swp_entry_t again and finally - * the swap type part is extracted. This will mask all bits - * from the initial ~0UL that can't be encoded in either the - * swp_entry_t or the architecture definition of a swap pte. - */ - if (type > swp_type(pte_to_swp_entry(swp_entry_to_pte(swp_entry(~0UL,0))))) { + if (type >= MAX_SWAPFILES) { spin_unlock(&swap_lock); goto out; } @@ -1426,8 +1477,7 @@ asmlinkage long sys_swapon(const char __user * specialfile, int swap_flags) error = -EINVAL; goto bad_swap; } - page = read_cache_page(mapping, 0, - (filler_t *)mapping->a_ops->readpage, swap_file); + page = read_mapping_page(mapping, 0, swap_file); if (IS_ERR(page)) { error = PTR_ERR(page); goto bad_swap; @@ -1540,7 +1590,7 @@ asmlinkage long sys_swapon(const char __user * specialfile, int swap_flags) goto bad_swap; } - down(&swapon_sem); + mutex_lock(&swapon_mutex); spin_lock(&swap_lock); p->flags = SWP_ACTIVE; nr_swap_pages += nr_good_pages; @@ -1566,7 +1616,7 @@ asmlinkage long sys_swapon(const char __user * specialfile, int swap_flags) swap_info[prev].next = p - swap_info; } spin_unlock(&swap_lock); - up(&swapon_sem); + mutex_unlock(&swapon_mutex); error = 0; goto out; bad_swap: @@ -1631,6 +1681,9 @@ int swap_duplicate(swp_entry_t entry) unsigned long offset, type; int result = 0; + if (is_migration_entry(entry)) + return 1; + type = swp_type(entry); if (type >= nr_swapfiles) goto bad_file;