* requirements, they are simply tossed out - we will never use those blocks
* for swapping.
*
- * For S_ISREG swapfiles we set S_SWAPFILE across the life of the swapon. This
- * prevents root from shooting her foot off by ftruncating an in-use swapfile,
- * which will scribble on the fs.
+ * For all swap devices we set S_SWAPFILE across the life of the swapon. This
+ * prevents users from writing to the swap device, which will corrupt memory.
*
* The amount of disk space which a single swap extent represents varies.
* Typically it is in the 1-4 megabyte range. So we can have hundreds of
inode = mapping->host;
if (S_ISBLK(inode->i_mode)) {
struct block_device *bdev = I_BDEV(inode);
+
set_blocksize(bdev, old_block_size);
blkdev_put(bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL);
- } else {
- inode_lock(inode);
- inode->i_flags &= ~S_SWAPFILE;
- inode_unlock(inode);
}
+
+ inode_lock(inode);
+ inode->i_flags &= ~S_SWAPFILE;
+ inode_unlock(inode);
filp_close(swap_file, NULL);
/*
p->flags |= SWP_BLKDEV;
} else if (S_ISREG(inode->i_mode)) {
p->bdev = inode->i_sb->s_bdev;
- inode_lock(inode);
- if (IS_SWAPFILE(inode))
- return -EBUSY;
- } else
- return -EINVAL;
+ }
+
+ inode_lock(inode);
+ if (IS_SWAPFILE(inode))
+ return -EBUSY;
return 0;
}
if (error)
goto bad_swap;
+ /*
+ * Flush any pending IO and dirty mappings before we start using this
+ * swap device.
+ */
+ inode->i_flags |= S_SWAPFILE;
+ error = inode_drain_writes(inode);
+ if (error) {
+ inode->i_flags &= ~S_SWAPFILE;
+ goto bad_swap;
+ }
+
mutex_lock(&swapon_mutex);
prio = -1;
if (swap_flags & SWAP_FLAG_PREFER)
atomic_inc(&proc_poll_event);
wake_up_interruptible(&proc_poll_wait);
- if (S_ISREG(inode->i_mode))
- inode->i_flags |= S_SWAPFILE;
error = 0;
goto out;
bad_swap:
if (inced_nr_rotate_swap)
atomic_dec(&nr_rotate_swap);
if (swap_file) {
- if (inode && S_ISREG(inode->i_mode)) {
+ if (inode) {
inode_unlock(inode);
inode = NULL;
}
}
if (name)
putname(name);
- if (inode && S_ISREG(inode->i_mode))
+ if (inode)
inode_unlock(inode);
if (!error)
enable_swap_slots_cache();