#include <linux/swap.h>
#include <linux/slab.h>
#include <linux/loop.h>
+#include <linux/compat.h>
#include <linux/suspend.h>
#include <linux/writeback.h>
#include <linux/buffer_head.h> /* for invalidate_bdev() */
#include <asm/uaccess.h>
-static int max_loop = 8;
-static struct loop_device *loop_dev;
-static struct gendisk **disks;
+static LIST_HEAD(loop_devices);
+static DEFINE_MUTEX(loop_devices_mutex);
/*
* Transfer functions
if (unlikely((loff_t)x != size))
return -EFBIG;
- set_capacity(disks[lo->lo_number], x);
+ set_capacity(lo->lo_disk, x);
return 0;
}
transfer_result = lo_do_transfer(lo, WRITE, page, offset,
bvec->bv_page, bv_offs, size, IV);
if (unlikely(transfer_result)) {
- char *kaddr;
-
/*
* The transfer failed, but we still write the data to
* keep prepare/commit calls balanced.
*/
printk(KERN_ERR "loop: transfer error block %llu\n",
(unsigned long long)index);
- kaddr = kmap_atomic(page, KM_USER0);
- memset(kaddr + offset, 0, size);
- kunmap_atomic(kaddr, KM_USER0);
+ zero_user_page(page, offset, size, KM_USER0);
}
flush_dcache_page(page);
ret = aops->commit_write(file, page, offset,
* and do_lo_send_write().
*/
static int __do_lo_send_write(struct file *file,
- u8 __user *buf, const int len, loff_t pos)
+ u8 *buf, const int len, loff_t pos)
{
ssize_t bw;
mm_segment_t old_fs = get_fs();
struct bio_vec *bvec, int bsize, loff_t pos, struct page *page)
{
ssize_t bw = __do_lo_send_write(lo->lo_backing_file,
- (u8 __user *)kmap(bvec->bv_page) + bvec->bv_offset,
+ kmap(bvec->bv_page) + bvec->bv_offset,
bvec->bv_len, pos);
kunmap(bvec->bv_page);
cond_resched();
bvec->bv_offset, bvec->bv_len, pos >> 9);
if (likely(!ret))
return __do_lo_send_write(lo->lo_backing_file,
- (u8 __user *)page_address(page), bvec->bv_len,
+ page_address(page), bvec->bv_len,
pos);
printk(KERN_ERR "loop: Transfer error at byte offset %llu, "
"length %i.\n", (unsigned long long)pos, bvec->bv_len);
lo->lo_queue->queuedata = lo;
lo->lo_queue->unplug_fn = loop_unplug;
- set_capacity(disks[lo->lo_number], size);
+ set_capacity(lo->lo_disk, size);
bd_set_size(bdev, size << 9);
set_blocksize(bdev, lo_blocksize);
lo->lo_device = NULL;
lo->lo_backing_file = NULL;
lo->lo_flags = 0;
- set_capacity(disks[lo->lo_number], 0);
- invalidate_bdev(bdev, 0);
+ set_capacity(lo->lo_disk, 0);
+ invalidate_bdev(bdev);
bd_set_size(bdev, 0);
mapping_set_gfp_mask(mapping, lo->old_gfp_mask);
lo->lo_state = Lo_unbound;
memset(lo->lo_encrypt_key, 0, LO_KEY_SIZE);
memset(lo->lo_crypt_name, 0, LO_NAME_SIZE);
memset(lo->lo_file_name, 0, LO_NAME_SIZE);
- invalidate_bdev(bdev, 0);
- set_capacity(disks[lo->lo_number], 0);
+ invalidate_bdev(bdev);
+ set_capacity(lo->lo_disk, 0);
bd_set_size(bdev, 0);
mapping_set_gfp_mask(filp->f_mapping, gfp);
lo->lo_state = Lo_unbound;
if (lo->lo_state != Lo_bound)
return -ENXIO;
- error = vfs_getattr(file->f_vfsmnt, file->f_dentry, &stat);
+ error = vfs_getattr(file->f_path.mnt, file->f_path.dentry, &stat);
if (error)
return error;
memset(info, 0, sizeof(*info));
return err;
}
+#ifdef CONFIG_COMPAT
+struct compat_loop_info {
+ compat_int_t lo_number; /* ioctl r/o */
+ compat_dev_t lo_device; /* ioctl r/o */
+ compat_ulong_t lo_inode; /* ioctl r/o */
+ compat_dev_t lo_rdevice; /* ioctl r/o */
+ compat_int_t lo_offset;
+ compat_int_t lo_encrypt_type;
+ compat_int_t lo_encrypt_key_size; /* ioctl w/o */
+ compat_int_t lo_flags; /* ioctl r/o */
+ char lo_name[LO_NAME_SIZE];
+ unsigned char lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */
+ compat_ulong_t lo_init[2];
+ char reserved[4];
+};
+
+/*
+ * Transfer 32-bit compatibility structure in userspace to 64-bit loop info
+ * - noinlined to reduce stack space usage in main part of driver
+ */
+static noinline int
+loop_info64_from_compat(const struct compat_loop_info __user *arg,
+ struct loop_info64 *info64)
+{
+ struct compat_loop_info info;
+
+ if (copy_from_user(&info, arg, sizeof(info)))
+ return -EFAULT;
+
+ memset(info64, 0, sizeof(*info64));
+ info64->lo_number = info.lo_number;
+ info64->lo_device = info.lo_device;
+ info64->lo_inode = info.lo_inode;
+ info64->lo_rdevice = info.lo_rdevice;
+ info64->lo_offset = info.lo_offset;
+ info64->lo_sizelimit = 0;
+ info64->lo_encrypt_type = info.lo_encrypt_type;
+ info64->lo_encrypt_key_size = info.lo_encrypt_key_size;
+ info64->lo_flags = info.lo_flags;
+ info64->lo_init[0] = info.lo_init[0];
+ info64->lo_init[1] = info.lo_init[1];
+ if (info.lo_encrypt_type == LO_CRYPT_CRYPTOAPI)
+ memcpy(info64->lo_crypt_name, info.lo_name, LO_NAME_SIZE);
+ else
+ memcpy(info64->lo_file_name, info.lo_name, LO_NAME_SIZE);
+ memcpy(info64->lo_encrypt_key, info.lo_encrypt_key, LO_KEY_SIZE);
+ return 0;
+}
+
+/*
+ * Transfer 64-bit loop info to 32-bit compatibility structure in userspace
+ * - noinlined to reduce stack space usage in main part of driver
+ */
+static noinline int
+loop_info64_to_compat(const struct loop_info64 *info64,
+ struct compat_loop_info __user *arg)
+{
+ struct compat_loop_info info;
+
+ memset(&info, 0, sizeof(info));
+ info.lo_number = info64->lo_number;
+ info.lo_device = info64->lo_device;
+ info.lo_inode = info64->lo_inode;
+ info.lo_rdevice = info64->lo_rdevice;
+ info.lo_offset = info64->lo_offset;
+ info.lo_encrypt_type = info64->lo_encrypt_type;
+ info.lo_encrypt_key_size = info64->lo_encrypt_key_size;
+ info.lo_flags = info64->lo_flags;
+ info.lo_init[0] = info64->lo_init[0];
+ info.lo_init[1] = info64->lo_init[1];
+ if (info.lo_encrypt_type == LO_CRYPT_CRYPTOAPI)
+ memcpy(info.lo_name, info64->lo_crypt_name, LO_NAME_SIZE);
+ else
+ memcpy(info.lo_name, info64->lo_file_name, LO_NAME_SIZE);
+ memcpy(info.lo_encrypt_key, info64->lo_encrypt_key, LO_KEY_SIZE);
+
+ /* error in case values were truncated */
+ if (info.lo_device != info64->lo_device ||
+ info.lo_rdevice != info64->lo_rdevice ||
+ info.lo_inode != info64->lo_inode ||
+ info.lo_offset != info64->lo_offset ||
+ info.lo_init[0] != info64->lo_init[0] ||
+ info.lo_init[1] != info64->lo_init[1])
+ return -EOVERFLOW;
+
+ if (copy_to_user(arg, &info, sizeof(info)))
+ return -EFAULT;
+ return 0;
+}
+
+static int
+loop_set_status_compat(struct loop_device *lo,
+ const struct compat_loop_info __user *arg)
+{
+ struct loop_info64 info64;
+ int ret;
+
+ ret = loop_info64_from_compat(arg, &info64);
+ if (ret < 0)
+ return ret;
+ return loop_set_status(lo, &info64);
+}
+
+static int
+loop_get_status_compat(struct loop_device *lo,
+ struct compat_loop_info __user *arg)
+{
+ struct loop_info64 info64;
+ int err = 0;
+
+ if (!arg)
+ err = -EINVAL;
+ if (!err)
+ err = loop_get_status(lo, &info64);
+ if (!err)
+ err = loop_info64_to_compat(&info64, arg);
+ return err;
+}
+
+static long lo_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ struct inode *inode = file->f_path.dentry->d_inode;
+ struct loop_device *lo = inode->i_bdev->bd_disk->private_data;
+ int err;
+
+ lock_kernel();
+ switch(cmd) {
+ case LOOP_SET_STATUS:
+ mutex_lock(&lo->lo_ctl_mutex);
+ err = loop_set_status_compat(
+ lo, (const struct compat_loop_info __user *) arg);
+ mutex_unlock(&lo->lo_ctl_mutex);
+ break;
+ case LOOP_GET_STATUS:
+ mutex_lock(&lo->lo_ctl_mutex);
+ err = loop_get_status_compat(
+ lo, (struct compat_loop_info __user *) arg);
+ mutex_unlock(&lo->lo_ctl_mutex);
+ break;
+ case LOOP_CLR_FD:
+ case LOOP_GET_STATUS64:
+ case LOOP_SET_STATUS64:
+ arg = (unsigned long) compat_ptr(arg);
+ case LOOP_SET_FD:
+ case LOOP_CHANGE_FD:
+ err = lo_ioctl(inode, file, cmd, arg);
+ break;
+ default:
+ err = -ENOIOCTLCMD;
+ break;
+ }
+ unlock_kernel();
+ return err;
+}
+#endif
+
+static struct loop_device *loop_find_dev(int number)
+{
+ struct loop_device *lo;
+
+ list_for_each_entry(lo, &loop_devices, lo_list) {
+ if (lo->lo_number == number)
+ return lo;
+ }
+ return NULL;
+}
+
+static struct loop_device *loop_init_one(int i);
static int lo_open(struct inode *inode, struct file *file)
{
struct loop_device *lo = inode->i_bdev->bd_disk->private_data;
lo->lo_refcnt++;
mutex_unlock(&lo->lo_ctl_mutex);
+ mutex_lock(&loop_devices_mutex);
+ if (!loop_find_dev(lo->lo_number + 1))
+ loop_init_one(lo->lo_number + 1);
+ mutex_unlock(&loop_devices_mutex);
+
return 0;
}
.open = lo_open,
.release = lo_release,
.ioctl = lo_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = lo_compat_ioctl,
+#endif
};
/*
* And now the modules code and kernel interface.
*/
+static int max_loop;
module_param(max_loop, int, 0);
-MODULE_PARM_DESC(max_loop, "Maximum number of loop devices (1-256)");
+MODULE_PARM_DESC(max_loop, "obsolete, loop device is created on-demand");
MODULE_LICENSE("GPL");
MODULE_ALIAS_BLOCKDEV_MAJOR(LOOP_MAJOR);
xfer_funcs[n] = NULL;
- for (lo = &loop_dev[0]; lo < &loop_dev[max_loop]; lo++) {
+ list_for_each_entry(lo, &loop_devices, lo_list) {
mutex_lock(&lo->lo_ctl_mutex);
if (lo->lo_encryption == xfer)
EXPORT_SYMBOL(loop_register_transfer);
EXPORT_SYMBOL(loop_unregister_transfer);
-static int __init loop_init(void)
+static struct loop_device *loop_init_one(int i)
{
- int i;
+ struct loop_device *lo;
+ struct gendisk *disk;
- if (max_loop < 1 || max_loop > 256) {
- printk(KERN_WARNING "loop: invalid max_loop (must be between"
- " 1 and 256), using default (8)\n");
- max_loop = 8;
- }
+ lo = kzalloc(sizeof(*lo), GFP_KERNEL);
+ if (!lo)
+ goto out;
+
+ lo->lo_queue = blk_alloc_queue(GFP_KERNEL);
+ if (!lo->lo_queue)
+ goto out_free_dev;
+
+ disk = lo->lo_disk = alloc_disk(1);
+ if (!disk)
+ goto out_free_queue;
+
+ mutex_init(&lo->lo_ctl_mutex);
+ lo->lo_number = i;
+ lo->lo_thread = NULL;
+ init_waitqueue_head(&lo->lo_event);
+ spin_lock_init(&lo->lo_lock);
+ disk->major = LOOP_MAJOR;
+ disk->first_minor = i;
+ disk->fops = &lo_fops;
+ disk->private_data = lo;
+ disk->queue = lo->lo_queue;
+ sprintf(disk->disk_name, "loop%d", i);
+ add_disk(disk);
+ list_add_tail(&lo->lo_list, &loop_devices);
+ return lo;
+
+out_free_queue:
+ blk_cleanup_queue(lo->lo_queue);
+out_free_dev:
+ kfree(lo);
+out:
+ return ERR_PTR(-ENOMEM);
+}
+
+static void loop_del_one(struct loop_device *lo)
+{
+ del_gendisk(lo->lo_disk);
+ blk_cleanup_queue(lo->lo_queue);
+ put_disk(lo->lo_disk);
+ list_del(&lo->lo_list);
+ kfree(lo);
+}
+
+static struct kobject *loop_probe(dev_t dev, int *part, void *data)
+{
+ unsigned int number = dev & MINORMASK;
+ struct loop_device *lo;
+
+ mutex_lock(&loop_devices_mutex);
+ lo = loop_find_dev(number);
+ if (lo == NULL)
+ lo = loop_init_one(number);
+ mutex_unlock(&loop_devices_mutex);
+
+ *part = 0;
+ if (IS_ERR(lo))
+ return (void *)lo;
+ else
+ return &lo->lo_disk->kobj;
+}
+
+static int __init loop_init(void)
+{
+ struct loop_device *lo;
if (register_blkdev(LOOP_MAJOR, "loop"))
return -EIO;
+ blk_register_region(MKDEV(LOOP_MAJOR, 0), 1UL << MINORBITS,
+ THIS_MODULE, loop_probe, NULL, NULL);
- loop_dev = kmalloc(max_loop * sizeof(struct loop_device), GFP_KERNEL);
- if (!loop_dev)
- goto out_mem1;
- memset(loop_dev, 0, max_loop * sizeof(struct loop_device));
+ lo = loop_init_one(0);
+ if (IS_ERR(lo))
+ goto out;
- disks = kmalloc(max_loop * sizeof(struct gendisk *), GFP_KERNEL);
- if (!disks)
- goto out_mem2;
+ if (max_loop) {
+ printk(KERN_INFO "loop: the max_loop option is obsolete "
+ "and will be removed in March 2008\n");
- for (i = 0; i < max_loop; i++) {
- disks[i] = alloc_disk(1);
- if (!disks[i])
- goto out_mem3;
}
-
- for (i = 0; i < max_loop; i++) {
- struct loop_device *lo = &loop_dev[i];
- struct gendisk *disk = disks[i];
-
- memset(lo, 0, sizeof(*lo));
- lo->lo_queue = blk_alloc_queue(GFP_KERNEL);
- if (!lo->lo_queue)
- goto out_mem4;
- mutex_init(&lo->lo_ctl_mutex);
- lo->lo_number = i;
- lo->lo_thread = NULL;
- init_waitqueue_head(&lo->lo_event);
- spin_lock_init(&lo->lo_lock);
- disk->major = LOOP_MAJOR;
- disk->first_minor = i;
- disk->fops = &lo_fops;
- sprintf(disk->disk_name, "loop%d", i);
- disk->private_data = lo;
- disk->queue = lo->lo_queue;
- }
-
- /* We cannot fail after we call this, so another loop!*/
- for (i = 0; i < max_loop; i++)
- add_disk(disks[i]);
- printk(KERN_INFO "loop: loaded (max %d devices)\n", max_loop);
+ printk(KERN_INFO "loop: module loaded\n");
return 0;
-out_mem4:
- while (i--)
- blk_cleanup_queue(loop_dev[i].lo_queue);
- i = max_loop;
-out_mem3:
- while (i--)
- put_disk(disks[i]);
- kfree(disks);
-out_mem2:
- kfree(loop_dev);
-out_mem1:
+out:
unregister_blkdev(LOOP_MAJOR, "loop");
printk(KERN_ERR "loop: ran out of memory\n");
return -ENOMEM;
}
-static void loop_exit(void)
+static void __exit loop_exit(void)
{
- int i;
+ struct loop_device *lo, *next;
- for (i = 0; i < max_loop; i++) {
- del_gendisk(disks[i]);
- blk_cleanup_queue(loop_dev[i].lo_queue);
- put_disk(disks[i]);
- }
+ list_for_each_entry_safe(lo, next, &loop_devices, lo_list)
+ loop_del_one(lo);
+
+ blk_unregister_region(MKDEV(LOOP_MAJOR, 0), 1UL << MINORBITS);
if (unregister_blkdev(LOOP_MAJOR, "loop"))
printk(KERN_WARNING "loop: cannot unregister blkdev\n");
-
- kfree(disks);
- kfree(loop_dev);
}
module_init(loop_init);