}
struct switch_request {
- struct file *file;
+ struct file *file, *virt_file;
struct completion wait;
};
mapping = file->f_mapping;
mapping_set_gfp_mask(old_file->f_mapping, lo->old_gfp_mask);
lo->lo_backing_file = file;
+ lo->lo_backing_virt_file = p->virt_file;
lo->lo_blocksize = S_ISBLK(mapping->host->i_mode) ?
mapping->host->i_bdev->bd_block_size : PAGE_SIZE;
lo->old_gfp_mask = mapping_gfp_mask(mapping);
* First it needs to flush existing IO, it does this by sending a magic
* BIO down the pipe. The completion of this BIO does the actual switch.
*/
-static int loop_switch(struct loop_device *lo, struct file *file)
+static int loop_switch(struct loop_device *lo, struct file *file,
+ struct file *virt_file)
{
struct switch_request w;
w.file = file;
+ w.virt_file = virt_file;
/* freeze queue and wait for completion of scheduled requests */
blk_mq_freeze_queue(lo->lo_queue);
return loop_switch(lo, NULL);
}
+static struct file *loop_real_file(struct file *file)
+{
+ struct file *f = NULL;
+
+ if (file->f_path.dentry->d_sb->s_op->real_loop)
+ f = file->f_path.dentry->d_sb->s_op->real_loop(file);
+ return f;
+}
+
static void loop_reread_partitions(struct loop_device *lo,
struct block_device *bdev)
{
unsigned int arg)
{
struct file *file, *old_file;
+ struct file *f, *virt_file = NULL, *old_virt_file;
struct inode *inode;
int error;
file = fget(arg);
if (!file)
goto out;
+ f = loop_real_file(file);
+ if (f) {
+ virt_file = file;
+ file = f;
+ get_file(file);
+ }
inode = file->f_mapping->host;
old_file = lo->lo_backing_file;
+ old_virt_file = lo->lo_backing_virt_file;
error = -EINVAL;
goto out_putf;
/* and ... switch */
- error = loop_switch(lo, file);
+ error = loop_switch(lo, file, virt_file);
if (error)
goto out_putf;
fput(old_file);
+ if (old_virt_file)
+ fput(old_virt_file);
if (lo->lo_flags & LO_FLAGS_PARTSCAN)
loop_reread_partitions(lo, bdev);
return 0;
out_putf:
fput(file);
+ if (virt_file)
+ fput(virt_file);
out:
return error;
}
return i && S_ISBLK(i->i_mode) && MAJOR(i->i_rdev) == LOOP_MAJOR;
}
+/*
+ * for AUFS
+ * no get/put for file.
+ */
+struct file *loop_backing_file(struct super_block *sb)
+{
+ struct file *ret;
+ struct loop_device *l;
+
+ ret = NULL;
+ if (MAJOR(sb->s_dev) == LOOP_MAJOR) {
+ l = sb->s_bdev->bd_disk->private_data;
+ ret = l->lo_backing_file;
+ }
+ return ret;
+}
+EXPORT_SYMBOL_GPL(loop_backing_file);
+
/* loop sysfs attributes */
static ssize_t loop_attr_show(struct device *dev, char *page,
static int loop_set_fd(struct loop_device *lo, fmode_t mode,
struct block_device *bdev, unsigned int arg)
{
- struct file *file, *f;
+ struct file *file, *f, *virt_file = NULL;
struct inode *inode;
struct address_space *mapping;
unsigned lo_blocksize;
file = fget(arg);
if (!file)
goto out;
+ f = loop_real_file(file);
+ if (f) {
+ virt_file = file;
+ file = f;
+ get_file(file);
+ }
error = -EBUSY;
if (lo->lo_state != Lo_unbound)
lo->lo_device = bdev;
lo->lo_flags = lo_flags;
lo->lo_backing_file = file;
+ lo->lo_backing_virt_file = virt_file;
lo->transfer = NULL;
lo->ioctl = NULL;
lo->lo_sizelimit = 0;
out_putf:
fput(file);
+ if (virt_file)
+ fput(virt_file);
out:
/* This is safe: open() is still holding a reference. */
module_put(THIS_MODULE);
static int loop_clr_fd(struct loop_device *lo)
{
struct file *filp = lo->lo_backing_file;
+ struct file *virt_filp = lo->lo_backing_virt_file;
gfp_t gfp = lo->old_gfp_mask;
struct block_device *bdev = lo->lo_device;
spin_lock_irq(&lo->lo_lock);
lo->lo_state = Lo_rundown;
lo->lo_backing_file = NULL;
+ lo->lo_backing_virt_file = NULL;
spin_unlock_irq(&lo->lo_lock);
loop_release_xfer(lo);
* bd_mutex which is usually taken before lo_ctl_mutex.
*/
fput(filp);
+ if (virt_filp)
+ fput(virt_filp);
return 0;
}