diff options
Diffstat (limited to 'mm/swapfile.c')
| -rw-r--r-- | mm/swapfile.c | 60 |
1 files changed, 41 insertions, 19 deletions
diff --git a/mm/swapfile.c b/mm/swapfile.c index edafeace301..f1e69c30d20 100644 --- 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; } |