Merge tag 'v3.12-rc2' into patchwork

Linux 3.12-rc2

* tag 'v3.12-rc2': (10774 commits)
  Linux 3.12-rc2
  cfq: explicitly use 64bit divide operation for 64bit arguments
  block: Add nr_bios to block_rq_remap tracepoint
  Btrfs: create the uuid tree on remount rw
  btrfs: change extent-same to copy entire argument struct
  Btrfs: dir_inode_operations should use btrfs_update_time also
  btrfs: Add btrfs: prefix to kernel log output
  btrfs: refuse to remount read-write after abort
  Btrfs: btrfs_ioctl_default_subvol: Revert back to toplevel subvolume when arg is 0
  Btrfs: don't leak transaction in btrfs_sync_file()
  Btrfs: add the missing mutex unlock in write_all_supers()
  Btrfs: iput inode on allocation failure
  Btrfs: remove space_info->reservation_progress
  Btrfs: kill delay_iput arg to the wait_ordered functions
  Btrfs: fix worst case calculator for space usage
  Revert "Btrfs: rework the overcommit logic to be based on the total size"
  Btrfs: improve replacing nocow extents
  Btrfs: drop dir i_size when adding new names on replay
  Btrfs: replay dir_index items before other items
  Btrfs: check roots last log commit when checking if an inode has been logged
  ...

1 files changed, 22 insertions, 0 deletions

diff --git a/crypto/scatterwalk.c b/crypto/scatterwalk.c
index 7281b8a9..79ca2278 100644
--- a/crypto/scatterwalk.c
+++ b/crypto/scatterwalk.c
@@ -124,3 +124,25 @@ void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg,
 	scatterwalk_done(&walk, out, 0);
 }
 EXPORT_SYMBOL_GPL(scatterwalk_map_and_copy);
+
+int scatterwalk_bytes_sglen(struct scatterlist *sg, int num_bytes)
+{
+	int offset = 0, n = 0;
+
+	/* num_bytes is too small */
+	if (num_bytes < sg->length)
+		return -1;
+
+	do {
+		offset += sg->length;
+		n++;
+		sg = scatterwalk_sg_next(sg);
+
+		/* num_bytes is too large */
+		if (unlikely(!sg && (num_bytes < offset)))
+			return -1;
+	} while (sg && (num_bytes > offset));
+
+	return n;
+}
+EXPORT_SYMBOL_GPL(scatterwalk_bytes_sglen);