ext4: let the block device know when unused blocks can be discarded
Let the block device know when unused blocks can be discarded, using
the new sb_issue_discard() interface.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index bd9b011..815a22e 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2653,6 +2653,7 @@
struct ext4_sb_info *sbi = EXT4_SB(sb);
int err, count = 0, count2 = 0;
struct ext4_free_data *entry;
+ ext4_fsblk_t discard_block;
if (list_empty(&sbi->s_committed_transaction))
return;
@@ -2696,6 +2697,12 @@
page_cache_release(e4b.bd_bitmap_page);
}
ext4_unlock_group(sb, entry->group);
+ discard_block = (ext4_fsblk_t) entry->group * EXT4_BLOCKS_PER_GROUP(sb)
+ + entry->start_blk
+ + le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
+ trace_mark(ext4_discard_blocks, "dev %s blk %llu count %u", sb->s_id,
+ (unsigned long long) discard_block, entry->count);
+ sb_issue_discard(sb, discard_block, entry->count);
kmem_cache_free(ext4_free_ext_cachep, entry);
ext4_mb_release_desc(&e4b);