btrfs: change extent-same to copy entire argument struct

btrfs_ioctl_file_extent_same() uses __put_user_unaligned() to copy some data
back to it's argument struct. Unfortunately, not all architectures provide
__put_user_unaligned(), so compiles break on them if btrfs is selected.

Instead, just copy the whole struct in / out at the start and end of
operations, respectively.

Signed-off-by: Mark Fasheh <mfasheh@suse.de>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index fba259ab99941e429fa7c5f55fc3a42229778efa..9d46f60cb9439ab3a41ab83f2f323f13aa564590 100644 (file)
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2696,9 +2696,9 @@ out_unlock:
 static long btrfs_ioctl_file_extent_same(struct file *file,
                                         void __user *argp)
 {
-       struct btrfs_ioctl_same_args *args = argp;
-       struct btrfs_ioctl_same_args same;
-       struct btrfs_ioctl_same_extent_info info;
+       struct btrfs_ioctl_same_args tmp;
+       struct btrfs_ioctl_same_args *same;
+       struct btrfs_ioctl_same_extent_info *info;
        struct inode *src = file->f_dentry->d_inode;
        struct file *dst_file = NULL;
        struct inode *dst;
@@ -2706,6 +2706,7 @@ static long btrfs_ioctl_file_extent_same(struct file *file,
        u64 len;
        int i;
        int ret;
+       unsigned long size;
        u64 bs = BTRFS_I(src)->root->fs_info->sb->s_blocksize;
        bool is_admin = capable(CAP_SYS_ADMIN);
 
@@ -2716,15 +2717,30 @@ static long btrfs_ioctl_file_extent_same(struct file *file,
        if (ret)
                return ret;
 
-       if (copy_from_user(&same,
+       if (copy_from_user(&tmp,
                           (struct btrfs_ioctl_same_args __user *)argp,
-                          sizeof(same))) {
+                          sizeof(tmp))) {
                ret = -EFAULT;
                goto out;
        }
 
-       off = same.logical_offset;
-       len = same.length;
+       size = sizeof(tmp) +
+               tmp.dest_count * sizeof(struct btrfs_ioctl_same_extent_info);
+
+       same = kmalloc(size, GFP_NOFS);
+       if (!same) {
+               ret = -EFAULT;
+               goto out;
+       }
+
+       if (copy_from_user(same,
+                          (struct btrfs_ioctl_same_args __user *)argp, size)) {
+               ret = -EFAULT;
+               goto out;
+       }
+
+       off = same->logical_offset;
+       len = same->length;
 
        /*
         * Limit the total length we will dedupe for each operation.
@@ -2752,27 +2768,28 @@ static long btrfs_ioctl_file_extent_same(struct file *file,
        if (!S_ISREG(src->i_mode))
                goto out;
 
-       ret = 0;
-       for (i = 0; i < same.dest_count; i++) {
-               if (copy_from_user(&info, &args->info[i], sizeof(info))) {
-                       ret = -EFAULT;
-                       goto out;
-               }
+       /* pre-format output fields to sane values */
+       for (i = 0; i < same->dest_count; i++) {
+               same->info[i].bytes_deduped = 0ULL;
+               same->info[i].status = 0;
+       }
 
-               info.bytes_deduped = 0;
+       ret = 0;
+       for (i = 0; i < same->dest_count; i++) {
+               info = &same->info[i];
 
-               dst_file = fget(info.fd);
+               dst_file = fget(info->fd);
                if (!dst_file) {
-                       info.status = -EBADF;
+                       info->status = -EBADF;
                        goto next;
                }
 
                if (!(is_admin || (dst_file->f_mode & FMODE_WRITE))) {
-                       info.status = -EINVAL;
+                       info->status = -EINVAL;
                        goto next;
                }
 
-               info.status = -EXDEV;
+               info->status = -EXDEV;
                if (file->f_path.mnt != dst_file->f_path.mnt)
                        goto next;
 
@@ -2781,32 +2798,29 @@ static long btrfs_ioctl_file_extent_same(struct file *file,
                        goto next;
 
                if (S_ISDIR(dst->i_mode)) {
-                       info.status = -EISDIR;
+                       info->status = -EISDIR;
                        goto next;
                }
 
                if (!S_ISREG(dst->i_mode)) {
-                       info.status = -EACCES;
+                       info->status = -EACCES;
                        goto next;
                }
 
-               info.status = btrfs_extent_same(src, off, len, dst,
-                                               info.logical_offset);
-               if (info.status == 0)
-                       info.bytes_deduped += len;
+               info->status = btrfs_extent_same(src, off, len, dst,
+                                               info->logical_offset);
+               if (info->status == 0)
+                       info->bytes_deduped += len;
 
 next:
                if (dst_file)
                        fput(dst_file);
-
-               if (__put_user_unaligned(info.status, &args->info[i].status) ||
-                   __put_user_unaligned(info.bytes_deduped,
-                                        &args->info[i].bytes_deduped)) {
-                       ret = -EFAULT;
-                       goto out;
-               }                                                               
        }
 
+       ret = copy_to_user(argp, same, size);
+       if (ret)
+               ret = -EFAULT;
+
 out:
        mnt_drop_write_file(file);
        return ret;