From 624b2a80fb86c5769681fe2482bf4ffdd802f920 Mon Sep 17 00:00:00 2001
From: Tao Ma <boyu.mt@taobao.com>
Date: Mon, 11 Jul 2011 00:03:38 -0400
Subject: [PATCH] --- yaml --- r: 262097 b: refs/heads/master c:
 3d56b8d2c74cc3f375ce332b3ac3519e009d79ee h: refs/heads/master i:   262095:
 0a6fc1dcbf04715c54bfce75fd4ea2bd3b31d3b3 v: v3

---
 [refs]                  |  2 +-
 trunk/fs/ext4/ext4.h    | 13 ++++++++++++-
 trunk/fs/ext4/mballoc.c | 20 ++++++++++++++++++++
 3 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/[refs] b/[refs]
index 07c62277bc68..02f873aa3d42 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: b3d4c2b10b68d205d3eb1b5c17dcb4649a502798
+refs/heads/master: 3d56b8d2c74cc3f375ce332b3ac3519e009d79ee
diff --git a/trunk/fs/ext4/ext4.h b/trunk/fs/ext4/ext4.h
index d13f3b509886..62cee2b6fe79 100644
--- a/trunk/fs/ext4/ext4.h
+++ b/trunk/fs/ext4/ext4.h
@@ -1215,6 +1215,9 @@ struct ext4_sb_info {
 
 	/* Kernel thread for multiple mount protection */
 	struct task_struct *s_mmp_tsk;
+
+	/* record the last minlen when FITRIM is called. */
+	atomic_t s_last_trim_minblks;
 };
 
 static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
@@ -2080,11 +2083,19 @@ struct ext4_group_info {
 					 * 5 free 8-block regions. */
 };
 
-#define EXT4_GROUP_INFO_NEED_INIT_BIT	0
+#define EXT4_GROUP_INFO_NEED_INIT_BIT		0
+#define EXT4_GROUP_INFO_WAS_TRIMMED_BIT		1
 
 #define EXT4_MB_GRP_NEED_INIT(grp)	\
 	(test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
 
+#define EXT4_MB_GRP_WAS_TRIMMED(grp)	\
+	(test_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
+#define EXT4_MB_GRP_SET_TRIMMED(grp)	\
+	(set_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
+#define EXT4_MB_GRP_CLEAR_TRIMMED(grp)	\
+	(clear_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
+
 #define EXT4_MAX_CONTENTION		8
 #define EXT4_CONTENTION_THRESHOLD	2
 
diff --git a/trunk/fs/ext4/mballoc.c b/trunk/fs/ext4/mballoc.c
index 7aa4c16caca1..73c254085a41 100644
--- a/trunk/fs/ext4/mballoc.c
+++ b/trunk/fs/ext4/mballoc.c
@@ -2628,6 +2628,15 @@ static void release_blocks_on_commit(journal_t *journal, transaction_t *txn)
 		rb_erase(&entry->node, &(db->bb_free_root));
 		mb_free_blocks(NULL, &e4b, entry->start_blk, entry->count);
 
+		/*
+		 * Clear the trimmed flag for the group so that the next
+		 * ext4_trim_fs can trim it.
+		 * If the volume is mounted with -o discard, online discard
+		 * is supported and the free blocks will be trimmed online.
+		 */
+		if (!test_opt(sb, DISCARD))
+			EXT4_MB_GRP_CLEAR_TRIMMED(db);
+
 		if (!db->bb_free_root.rb_node) {
 			/* No more items in the per group rb tree
 			 * balance refcounts from ext4_mb_free_metadata()
@@ -4838,6 +4847,10 @@ ext4_trim_all_free(struct super_block *sb, ext4_group_t group,
 	bitmap = e4b.bd_bitmap;
 
 	ext4_lock_group(sb, group);
+	if (EXT4_MB_GRP_WAS_TRIMMED(e4b.bd_info) &&
+	    minblocks >= atomic_read(&EXT4_SB(sb)->s_last_trim_minblks))
+		goto out;
+
 	start = (e4b.bd_info->bb_first_free > start) ?
 		e4b.bd_info->bb_first_free : start;
 
@@ -4869,6 +4882,10 @@ ext4_trim_all_free(struct super_block *sb, ext4_group_t group,
 		if ((e4b.bd_info->bb_free - free_count) < minblocks)
 			break;
 	}
+
+	if (!ret)
+		EXT4_MB_GRP_SET_TRIMMED(e4b.bd_info);
+out:
 	ext4_unlock_group(sb, group);
 	ext4_mb_unload_buddy(&e4b);
 
@@ -4957,6 +4974,9 @@ int ext4_trim_fs(struct super_block *sb, struct fstrim_range *range)
 	}
 	range->len = trimmed * sb->s_blocksize;
 
+	if (!ret)
+		atomic_set(&EXT4_SB(sb)->s_last_trim_minblks, minlen);
+
 out:
 	return ret;
 }