ext4: add a function which extends a group without checking parameters

This patch added a function named ext4_group_extend_no_check() whose code
is copied from ext4_group_extend().  ext4_group_extend_no_check() assumes
the parameter is valid and has been checked by caller.

Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index 996780ab4f4e83cdfc114e83ab8cad35242f4813..1c3c2b56049d9e3190d7994e8dc0573e55864519 100644 (file)
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -968,6 +968,57 @@ exit_put:
        return err;
 } /* ext4_group_add */
 
+/*
+ * extend a group without checking assuming that checking has been done.
+ */
+static int ext4_group_extend_no_check(struct super_block *sb,
+                                     ext4_fsblk_t o_blocks_count, ext4_grpblk_t add)
+{
+       struct ext4_super_block *es = EXT4_SB(sb)->s_es;
+       handle_t *handle;
+       int err = 0, err2;
+
+       /* We will update the superblock, one block bitmap, and
+        * one group descriptor via ext4_group_add_blocks().
+        */
+       handle = ext4_journal_start_sb(sb, 3);
+       if (IS_ERR(handle)) {
+               err = PTR_ERR(handle);
+               ext4_warning(sb, "error %d on journal start", err);
+               return err;
+       }
+
+       err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
+       if (err) {
+               ext4_warning(sb, "error %d on journal write access", err);
+               goto errout;
+       }
+
+       ext4_blocks_count_set(es, o_blocks_count + add);
+       ext4_debug("freeing blocks %llu through %llu\n", o_blocks_count,
+                  o_blocks_count + add);
+       /* We add the blocks to the bitmap and set the group need init bit */
+       err = ext4_group_add_blocks(handle, sb, o_blocks_count, add);
+       if (err)
+               goto errout;
+       ext4_handle_dirty_super(handle, sb);
+       ext4_debug("freed blocks %llu through %llu\n", o_blocks_count,
+                  o_blocks_count + add);
+errout:
+       err2 = ext4_journal_stop(handle);
+       if (err2 && !err)
+               err = err2;
+
+       if (!err) {
+               if (test_opt(sb, DEBUG))
+                       printk(KERN_DEBUG "EXT4-fs: extended group to %llu "
+                              "blocks\n", ext4_blocks_count(es));
+               update_backups(sb, EXT4_SB(sb)->s_sbh->b_blocknr, (char *)es,
+                              sizeof(struct ext4_super_block));
+       }
+       return err;
+}
+
 /*
  * Extend the filesystem to the new number of blocks specified.  This entry
  * point is only used to extend the current filesystem to the end of the last