1 files changed, 51 insertions, 14 deletions

diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index 321b7fb4e441..c85e7c6b4598 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -85,6 +85,7 @@ struct send_ctx {
         u32 send_max_size;
         u64 total_send_size;
         u64 cmd_send_size[BTRFS_SEND_C_MAX + 1];
+        u64 flags;      /* 'flags' member of btrfs_ioctl_send_args is u64 */
 
         struct vfsmount *mnt;
 
@@ -3709,6 +3710,39 @@ out:
         return ret;
 }
 
+/*
+ * Send an update extent command to user space.
+ */
+static int send_update_extent(struct send_ctx *sctx,
+                              u64 offset, u32 len)
+{
+        int ret = 0;
+        struct fs_path *p;
+
+        p = fs_path_alloc(sctx);
+        if (!p)
+                return -ENOMEM;
+
+        ret = begin_cmd(sctx, BTRFS_SEND_C_UPDATE_EXTENT);
+        if (ret < 0)
+                goto out;
+
+        ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
+        if (ret < 0)
+                goto out;
+
+        TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
+        TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
+        TLV_PUT_U64(sctx, BTRFS_SEND_A_SIZE, len);
+
+        ret = send_cmd(sctx);
+
+tlv_put_failure:
+out:
+        fs_path_free(sctx, p);
+        return ret;
+}
+
 static int send_write_or_clone(struct send_ctx *sctx,
                                struct btrfs_path *path,
                                struct btrfs_key *key,
@@ -3744,7 +3778,11 @@ static int send_write_or_clone(struct send_ctx *sctx,
                 goto out;
         }
 
-        if (!clone_root) {
+        if (clone_root) {
+                ret = send_clone(sctx, offset, len, clone_root);
+        } else if (sctx->flags & BTRFS_SEND_FLAG_NO_FILE_DATA) {
+                ret = send_update_extent(sctx, offset, len);
+        } else {
                 while (pos < len) {
                         l = len - pos;
                         if (l > BTRFS_SEND_READ_SIZE)
@@ -3757,10 +3795,7 @@ static int send_write_or_clone(struct send_ctx *sctx,
                         pos += ret;
                 }
                 ret = 0;
-        } else {
-                ret = send_clone(sctx, offset, len, clone_root);
         }
-
 out:
         return ret;
 }
@@ -3910,12 +3945,10 @@ static int is_extent_unchanged(struct send_ctx *sctx,
                     found_key.type != key.type) {
                         key.offset += right_len;
                         break;
-                } else {
-                        if (found_key.offset != key.offset + right_len) {
-                                /* Should really not happen */
-                                ret = -EIO;
-                                goto out;
-                        }
+                }
+                if (found_key.offset != key.offset + right_len) {
+                        ret = 0;
+                        goto out;
                 }
                 key = found_key;
         }
@@ -4536,7 +4569,6 @@ long btrfs_ioctl_send(struct file *mnt_file, void __user *arg_)
         struct btrfs_fs_info *fs_info;
         struct btrfs_ioctl_send_args *arg = NULL;
         struct btrfs_key key;
-        struct file *filp = NULL;
         struct send_ctx *sctx = NULL;
         u32 i;
         u64 *clone_sources_tmp = NULL;
@@ -4544,7 +4576,7 @@ long btrfs_ioctl_send(struct file *mnt_file, void __user *arg_)
         if (!capable(CAP_SYS_ADMIN))
                 return -EPERM;
 
-        send_root = BTRFS_I(fdentry(mnt_file)->d_inode)->root;
+        send_root = BTRFS_I(file_inode(mnt_file))->root;
         fs_info = send_root->fs_info;
 
         arg = memdup_user(arg_, sizeof(*arg));
@@ -4561,6 +4593,11 @@ long btrfs_ioctl_send(struct file *mnt_file, void __user *arg_)
                 goto out;
         }
 
+        if (arg->flags & ~BTRFS_SEND_FLAG_NO_FILE_DATA) {
+                ret = -EINVAL;
+                goto out;
+        }
+
         sctx = kzalloc(sizeof(struct send_ctx), GFP_NOFS);
         if (!sctx) {
                 ret = -ENOMEM;
@@ -4572,6 +4609,8 @@ long btrfs_ioctl_send(struct file *mnt_file, void __user *arg_)
         INIT_RADIX_TREE(&sctx->name_cache, GFP_NOFS);
         INIT_LIST_HEAD(&sctx->name_cache_list);
 
+        sctx->flags = arg->flags;
+
         sctx->send_filp = fget(arg->send_fd);
         if (IS_ERR(sctx->send_filp)) {
                 ret = PTR_ERR(sctx->send_filp);
@@ -4673,8 +4712,6 @@ long btrfs_ioctl_send(struct file *mnt_file, void __user *arg_)
                 goto out;
 
 out:
-        if (filp)
-                fput(filp);
         kfree(arg);
         vfree(clone_sources_tmp);