Merge branch 'for-linus' of master.kernel.org:/pub/scm/linux/kernel/git/roland/infiniband

[linux-2.6-omap-h63xx.git] / mm / swapfile.c

diff --git a/mm/swapfile.c b/mm/swapfile.c
index edafeace301f01879e04d31c9bf9e5c01a4484e9..f1e69c30d203871146d10b13b4e90831b2f0f7cf 100644 (file)
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -25,6 +25,8 @@
 #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>
 
 #include <asm/pgtable.h>
@@ -45,12 +47,12 @@ struct swap_list_t swap_list = {-1, -1};
 
 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);
 
@@ -211,6 +213,26 @@ noswap:
        return (swp_entry_t) {0};
 }
 
+swp_entry_t get_swap_page_of_type(int type)
+{
+       struct swap_info_struct *si;
+       pgoff_t offset;
+
+       spin_lock(&swap_lock);
+       si = swap_info + type;
+       if (si->flags & SWP_WRITEOK) {
+               nr_swap_pages--;
+               offset = scan_swap_map(si);
+               if (offset) {
+                       spin_unlock(&swap_lock);
+                       return swp_entry(type, offset);
+               }
+               nr_swap_pages++;
+       }
+       spin_unlock(&swap_lock);
+       return (swp_entry_t) {0};
+}
+
 static struct swap_info_struct * swap_info_get(swp_entry_t entry)
 {
        struct swap_info_struct * p;
@@ -1140,7 +1162,7 @@ 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();
 
@@ -1159,7 +1181,7 @@ 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)) {
@@ -1167,9 +1189,9 @@ asmlinkage long sys_swapoff(const char __user * specialfile)
                set_blocksize(bdev, p->old_block_size);
                bd_release(bdev);
        } else {
-               down(&inode->i_sem);
+               mutex_lock(&inode->i_mutex);
                inode->i_flags &= ~S_SWAPFILE;
-               up(&inode->i_sem);
+               mutex_unlock(&inode->i_mutex);
        }
        filp_close(swap_file, NULL);
        err = 0;
@@ -1188,7 +1210,7 @@ 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)
@@ -1217,7 +1239,7 @@ 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)
@@ -1386,7 +1408,7 @@ asmlinkage long sys_swapon(const char __user * specialfile, int swap_flags)
                p->bdev = bdev;
        } else if (S_ISREG(inode->i_mode)) {
                p->bdev = inode->i_sb->s_bdev;
-               down(&inode->i_sem);
+               mutex_lock(&inode->i_mutex);
                did_down = 1;
                if (IS_SWAPFILE(inode)) {
                        error = -EBUSY;
@@ -1422,7 +1444,7 @@ asmlinkage long sys_swapon(const char __user * specialfile, int swap_flags)
        else if (!memcmp("SWAPSPACE2",swap_header->magic.magic,10))
                swap_header_version = 2;
        else {
-               printk("Unable to find swap-space signature\n");
+               printk(KERN_ERR "Unable to find swap-space signature\n");
                error = -EINVAL;
                goto bad_swap;
        }
@@ -1473,7 +1495,7 @@ asmlinkage long sys_swapon(const char __user * specialfile, int swap_flags)
                        goto bad_swap;
                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;
@@ -1482,17 +1504,17 @@ asmlinkage long sys_swapon(const char __user * specialfile, int swap_flags)
 
                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)
+               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] = SWAP_MAP_BAD;
+                               p->swap_map[page_nr] = SWAP_MAP_BAD;
                }
                nr_good_pages = swap_header->info.last_page -
                                swap_header->info.nr_badpages -
                                1 /* header page */;
-               if (error) 
+               if (error)
                        goto bad_swap;
        }
 
@@ -1519,7 +1541,7 @@ 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;
@@ -1545,7 +1567,7 @@ 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:
@@ -1576,7 +1598,7 @@ out:
        if (did_down) {
                if (!error)
                        inode->i_flags |= S_SWAPFILE;
-               up(&inode->i_sem);
+               mutex_unlock(&inode->i_mutex);
        }
        return error;
 }