ext4: move ext4_add_groupblocks() to mballoc.c

In preparation for the next patch, the function ext4_add_groupblocks()
is moved to mballoc.c, where it could use some static functions.

Signed-off-by: Amir Goldstein <amir73il@users.sf.net>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 124 insertions, 0 deletions

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 730c1a72a959..92aa05ddef66 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -4700,6 +4700,130 @@ error_return:
 }
 
 /**
+ * ext4_add_groupblocks() -- Add given blocks to an existing group
+ * @handle:                     handle to this transaction
+ * @sb:                         super block
+ * @block:                      start physcial block to add to the block group
+ * @count:                      number of blocks to free
+ *
+ * This marks the blocks as free in the bitmap. We ask the
+ * mballoc to reload the buddy after this by setting group
+ * EXT4_GROUP_INFO_NEED_INIT_BIT flag
+ */
+void ext4_add_groupblocks(handle_t *handle, struct super_block *sb,
+                         ext4_fsblk_t block, unsigned long count)
+{
+        struct buffer_head *bitmap_bh = NULL;
+        struct buffer_head *gd_bh;
+        ext4_group_t block_group;
+        ext4_grpblk_t bit;
+        unsigned int i;
+        struct ext4_group_desc *desc;
+        struct ext4_sb_info *sbi = EXT4_SB(sb);
+        int err = 0, ret, blk_free_count;
+        ext4_grpblk_t blocks_freed;
+        struct ext4_group_info *grp;
+
+        ext4_debug("Adding block(s) %llu-%llu\n", block, block + count - 1);
+
+        ext4_get_group_no_and_offset(sb, block, &block_group, &bit);
+        grp = ext4_get_group_info(sb, block_group);
+        /*
+         * Check to see if we are freeing blocks across a group
+         * boundary.
+         */
+        if (bit + count > EXT4_BLOCKS_PER_GROUP(sb)) {
+                goto error_return;
+        }
+        bitmap_bh = ext4_read_block_bitmap(sb, block_group);
+        if (!bitmap_bh)
+                goto error_return;
+        desc = ext4_get_group_desc(sb, block_group, &gd_bh);
+        if (!desc)
+                goto error_return;
+
+        if (in_range(ext4_block_bitmap(sb, desc), block, count) ||
+            in_range(ext4_inode_bitmap(sb, desc), block, count) ||
+            in_range(block, ext4_inode_table(sb, desc), sbi->s_itb_per_group) ||
+            in_range(block + count - 1, ext4_inode_table(sb, desc),
+                     sbi->s_itb_per_group)) {
+                ext4_error(sb, "Adding blocks in system zones - "
+                           "Block = %llu, count = %lu",
+                           block, count);
+                goto error_return;
+        }
+
+        /*
+         * We are about to add blocks to the bitmap,
+         * so we need undo access.
+         */
+        BUFFER_TRACE(bitmap_bh, "getting undo access");
+        err = ext4_journal_get_undo_access(handle, bitmap_bh);
+        if (err)
+                goto error_return;
+
+        /*
+         * We are about to modify some metadata.  Call the journal APIs
+         * to unshare ->b_data if a currently-committing transaction is
+         * using it
+         */
+        BUFFER_TRACE(gd_bh, "get_write_access");
+        err = ext4_journal_get_write_access(handle, gd_bh);
+        if (err)
+                goto error_return;
+        /*
+         * make sure we don't allow a parallel init on other groups in the
+         * same buddy cache
+         */
+        down_write(&grp->alloc_sem);
+        for (i = 0, blocks_freed = 0; i < count; i++) {
+                BUFFER_TRACE(bitmap_bh, "clear bit");
+                if (!ext4_clear_bit_atomic(ext4_group_lock_ptr(sb, block_group),
+                                                bit + i, bitmap_bh->b_data)) {
+                        ext4_error(sb, "bit already cleared for block %llu",
+                                   (ext4_fsblk_t)(block + i));
+                        BUFFER_TRACE(bitmap_bh, "bit already cleared");
+                } else {
+                        blocks_freed++;
+                }
+        }
+        ext4_lock_group(sb, block_group);
+        blk_free_count = blocks_freed + ext4_free_blks_count(sb, desc);
+        ext4_free_blks_set(sb, desc, blk_free_count);
+        desc->bg_checksum = ext4_group_desc_csum(sbi, block_group, desc);
+        ext4_unlock_group(sb, block_group);
+        percpu_counter_add(&sbi->s_freeblocks_counter, blocks_freed);
+
+        if (sbi->s_log_groups_per_flex) {
+                ext4_group_t flex_group = ext4_flex_group(sbi, block_group);
+                atomic_add(blocks_freed,
+                           &sbi->s_flex_groups[flex_group].free_blocks);
+        }
+        /*
+         * request to reload the buddy with the
+         * new bitmap information
+         */
+        set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &(grp->bb_state));
+        grp->bb_free += blocks_freed;
+        up_write(&grp->alloc_sem);
+
+        /* We dirtied the bitmap block */
+        BUFFER_TRACE(bitmap_bh, "dirtied bitmap block");
+        err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
+
+        /* And the group descriptor block */
+        BUFFER_TRACE(gd_bh, "dirtied group descriptor block");
+        ret = ext4_handle_dirty_metadata(handle, NULL, gd_bh);
+        if (!err)
+                err = ret;
+
+error_return:
+        brelse(bitmap_bh);
+        ext4_std_error(sb, err);
+        return;
+}
+
+/**
  * ext4_trim_extent -- function to TRIM one single free extent in the group
  * @sb:         super block for the file system
  * @start:      starting block of the free extent in the alloc. group