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>

1 files changed, 51 insertions, 0 deletions

diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index 996780ab4f4e..1c3c2b56049d 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -969,6 +969,57 @@ exit_put:
 } /* 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
  * existing group.  It can be accessed via ioctl, or by "remount,resize=<size>"