2 files changed, 51 insertions, 0 deletions

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 393a543a519e..6ea15469c63f 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2172,6 +2172,45 @@ static noinline int btrfs_ioctl_tree_search(struct file *file,
         return ret;
 }
 
+static noinline int btrfs_ioctl_tree_search_v2(struct file *file,
+                                               void __user *argp)
+{
+        struct btrfs_ioctl_search_args_v2 __user *uarg;
+        struct btrfs_ioctl_search_args_v2 args;
+        struct inode *inode;
+        int ret;
+        size_t buf_size;
+        const size_t buf_limit = 16 * 1024 * 1024;
+
+        if (!capable(CAP_SYS_ADMIN))
+                return -EPERM;
+
+        /* copy search header and buffer size */
+        uarg = (struct btrfs_ioctl_search_args_v2 __user *)argp;
+        if (copy_from_user(&args, uarg, sizeof(args)))
+                return -EFAULT;
+
+        buf_size = args.buf_size;
+
+        if (buf_size < sizeof(struct btrfs_ioctl_search_header))
+                return -EOVERFLOW;
+
+        /* limit result size to 16MB */
+        if (buf_size > buf_limit)
+                buf_size = buf_limit;
+
+        inode = file_inode(file);
+        ret = search_ioctl(inode, &args.key, &buf_size,
+                           (char *)(&uarg->buf[0]));
+        if (ret == 0 && copy_to_user(&uarg->key, &args.key, sizeof(args.key)))
+                ret = -EFAULT;
+        else if (ret == -EOVERFLOW &&
+                copy_to_user(&uarg->buf_size, &buf_size, sizeof(buf_size)))
+                ret = -EFAULT;
+
+        return ret;
+}
+
 /*
  * Search INODE_REFs to identify path name of 'dirid' directory
  * in a 'tree_id' tree. and sets path name to 'name'.
@@ -5252,6 +5291,8 @@ long btrfs_ioctl(struct file *file, unsigned int
                 return btrfs_ioctl_trans_end(file);
         case BTRFS_IOC_TREE_SEARCH:
                 return btrfs_ioctl_tree_search(file, argp);
+        case BTRFS_IOC_TREE_SEARCH_V2:
+                return btrfs_ioctl_tree_search_v2(file, argp);
         case BTRFS_IOC_INO_LOOKUP:
                 return btrfs_ioctl_ino_lookup(file, argp);
         case BTRFS_IOC_INO_PATHS:
diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h
index 7554fd381a56..6f9c38ce45c7 100644
--- a/include/uapi/linux/btrfs.h
+++ b/include/uapi/linux/btrfs.h
@@ -306,6 +306,14 @@ struct btrfs_ioctl_search_args {
         char buf[BTRFS_SEARCH_ARGS_BUFSIZE];
 };
 
+struct btrfs_ioctl_search_args_v2 {
+        struct btrfs_ioctl_search_key key; /* in/out - search parameters */
+        __u64 buf_size;            /* in - size of buffer
+                                            * out - on EOVERFLOW: needed size
+                                            *       to store item */
+        __u64 buf[0];                       /* out - found items */
+};
+
 struct btrfs_ioctl_clone_range_args {
   __s64 src_fd;
   __u64 src_offset, src_length;
@@ -558,6 +566,8 @@ static inline char *btrfs_err_str(enum btrfs_err_code err_code)
                                 struct btrfs_ioctl_defrag_range_args)
 #define BTRFS_IOC_TREE_SEARCH _IOWR(BTRFS_IOCTL_MAGIC, 17, \
                                    struct btrfs_ioctl_search_args)
+#define BTRFS_IOC_TREE_SEARCH_V2 _IOWR(BTRFS_IOCTL_MAGIC, 17, \
+                                           struct btrfs_ioctl_search_args_v2)
 #define BTRFS_IOC_INO_LOOKUP _IOWR(BTRFS_IOCTL_MAGIC, 18, \
                                    struct btrfs_ioctl_ino_lookup_args)
 #define BTRFS_IOC_DEFAULT_SUBVOL _IOW(BTRFS_IOCTL_MAGIC, 19, __u64)