libext2fs: factor out get_midpoint_journal_block() in mkjournal.c

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/lib/ext2fs/mkjournal.c b/lib/ext2fs/mkjournal.c
index d09c458..8c97e7a 100644 (file)
--- a/lib/ext2fs/mkjournal.c
+++ b/lib/ext2fs/mkjournal.c
@@ -295,13 +295,43 @@ static int mkjournal_proc(ext2_filsys     fs,
 }
 
 /*
+ * Calculate the initial goal block to be roughly at the middle of the
+ * filesystem.  Pick a group that has the largest number of free
+ * blocks.
+ */
+static blk64_t get_midpoint_journal_block(ext2_filsys fs)
+{
+       dgrp_t  group, start, end, i, log_flex;
+
+       group = ext2fs_group_of_blk2(fs, (ext2fs_blocks_count(fs->super) -
+                                        fs->super->s_first_data_block) / 2);
+       log_flex = 1 << fs->super->s_log_groups_per_flex;
+       if (fs->super->s_log_groups_per_flex && (group > log_flex)) {
+               group = group & ~(log_flex - 1);
+               while ((group < fs->group_desc_count) &&
+                      ext2fs_bg_free_blocks_count(fs, group) == 0)
+                       group++;
+               if (group == fs->group_desc_count)
+                       group = 0;
+               start = group;
+       } else
+               start = (group > 0) ? group-1 : group;
+       end = ((group+1) < fs->group_desc_count) ? group+1 : group;
+       group = start;
+       for (i = start + 1; i <= end; i++)
+               if (ext2fs_bg_free_blocks_count(fs, i) >
+                   ext2fs_bg_free_blocks_count(fs, group))
+                       group = i;
+       return ext2fs_group_first_block2(fs, group);
+}
+
+/*
  * This function creates a journal using direct I/O routines.
  */
 static errcode_t write_journal_inode(ext2_filsys fs, ext2_ino_t journal_ino,
                                     blk_t num_blocks, int flags)
 {
        char                    *buf;
-       dgrp_t                  group, start, end, i, log_flex;
        errcode_t               retval;
        struct ext2_inode       inode;
        unsigned long long      inode_size;
@@ -328,6 +358,7 @@ static errcode_t write_journal_inode(ext2_filsys fs, ext2_ino_t journal_ino,
        es.err = 0;
        es.flags = flags;
        es.zero_count = 0;
+       es.goal = get_midpoint_journal_block(fs);
 
        if (fs->super->s_feature_incompat & EXT3_FEATURE_INCOMPAT_EXTENTS) {
                inode.i_flags |= EXT4_EXTENTS_FL;
@@ -335,32 +366,6 @@ static errcode_t write_journal_inode(ext2_filsys fs, ext2_ino_t journal_ino,
                        goto out2;
        }
 
-       /*
-        * Set the initial goal block to be roughly at the middle of
-        * the filesystem.  Pick a group that has the largest number
-        * of free blocks.
-        */
-       group = ext2fs_group_of_blk2(fs, (ext2fs_blocks_count(fs->super) -
-                                        fs->super->s_first_data_block) / 2);
-       log_flex = 1 << fs->super->s_log_groups_per_flex;
-       if (fs->super->s_log_groups_per_flex && (group > log_flex)) {
-               group = group & ~(log_flex - 1);
-               while ((group < fs->group_desc_count) &&
-                      ext2fs_bg_free_blocks_count(fs, group) == 0)
-                       group++;
-               if (group == fs->group_desc_count)
-                       group = 0;
-               start = group;
-       } else
-               start = (group > 0) ? group-1 : group;
-       end = ((group+1) < fs->group_desc_count) ? group+1 : group;
-       group = start;
-       for (i=start+1; i <= end; i++)
-               if (ext2fs_bg_free_blocks_count(fs, i) >
-                   ext2fs_bg_free_blocks_count(fs, group))
-                       group = i;
-
-       es.goal = ext2fs_group_first_block2(fs, group);
        retval = ext2fs_block_iterate3(fs, journal_ino, BLOCK_FLAG_APPEND,
                                       0, mkjournal_proc, &es);
        if (es.err) {