X-Git-Url: https://git.karo-electronics.de/?a=blobdiff_plain;f=mm%2Fswapfile.c;h=39aa9d12961207ba7c537ed73da2eab54ea98dd9;hb=b9e71ac13a71bb435a4146d868080f5389bb906c;hp=957fef43fa6081ec62cf3459e3b5db2d865eae57;hpb=37ef4399a6bb265d3035e6d6e45f7677b132a3ba;p=karo-tx-linux.git

diff --git a/mm/swapfile.c b/mm/swapfile.c
index 957fef43fa60..39aa9d129612 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -25,6 +25,7 @@
 #include <linux/rmap.h>
 #include <linux/security.h>
 #include <linux/backing-dev.h>
+#include <linux/mutex.h>
 #include <linux/capability.h>
 #include <linux/syscalls.h>
 
@@ -44,14 +45,14 @@ 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 +116,7 @@ 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)) {
@@ -416,6 +417,61 @@ 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->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
@@ -553,6 +609,15 @@ static int unuse_mm(struct mm_struct *mm,
 	return 0;
 }
 
+#ifdef CONFIG_MIGRATION
+int remove_vma_swap(struct vm_area_struct *vma, struct page *page)
+{
+	swp_entry_t entry = { .val = page_private(page) };
+
+	return unuse_vma(vma, entry, page);
+}
+#endif
+
 /*
  * Scan swap_map from current position to next entry still in use.
  * Recycle to start on reaching the end, returning 0 when empty.
@@ -645,6 +710,7 @@ static int try_to_unuse(unsigned int type)
 		 */
 		swap_map = &si->swap_map[i];
 		entry = swp_entry(type, i);
+again:
 		page = read_swap_cache_async(entry, NULL, 0);
 		if (!page) {
 			/*
@@ -679,6 +745,12 @@ static int try_to_unuse(unsigned int type)
 		wait_on_page_locked(page);
 		wait_on_page_writeback(page);
 		lock_page(page);
+		if (!PageSwapCache(page)) {
+			/* Page migration has occured */
+			unlock_page(page);
+			page_cache_release(page);
+			goto again;
+		}
 		wait_on_page_writeback(page);
 
 		/*
@@ -1161,7 +1233,7 @@ 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 +1252,7 @@ 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 +1281,7 @@ 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 +1310,7 @@ 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)
@@ -1540,7 +1612,7 @@ 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 +1638,7 @@ 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: