From: Tao Ma <boyu.mt@xxxxxxxxxx>
In ext4, when FITRIM is called every time, we iterate all the
groups and do trim one by one. It is a bit time wasting if the
group has been trimmed and there is no change since the last
trim.
So this patch adds a new flag in ext4_group_info->bb_state to
indicate that the group has been trimmed, and it will be cleared
if some blocks is freed(in release_blocks_on_commit). Another
trim_minlen is added in ext4_sb_info to record the last minlen
we use to trim the volume, so that if the caller provide a small
one, we will go on the trim regardless of the bb_state. The idea
is inspired by Andreas and Lukas Czerner.
Cc: Andreas Dilger <adilger.kernel@xxxxxxxxx>
Cc: Lukas Czerner <lczerner@xxxxxxxxxx>
Signed-off-by: Tao Ma <boyu.mt@xxxxxxxxxx>
---
fs/ext4/ext4.h | 8 +++++++-
fs/ext4/mballoc.c | 22 ++++++++++++++++++++++
2 files changed, 29 insertions(+), 1 deletions(-)
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 0c8d97b..684f48e 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1200,6 +1200,9 @@ struct ext4_sb_info {
struct ext4_li_request *s_li_request;
/* Wait multiplier for lazy initialization thread */
unsigned int s_li_wait_mult;
+
+ /* record the last minlen when FITRIM is called. */
+ u64 trim_minlen;
};
static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
@@ -1970,10 +1973,13 @@ 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_HAS_BEEN_TRIMMED 1
#define EXT4_MB_GRP_NEED_INIT(grp) \
(test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
+#define EXT4_MB_GRP_HAS_BEEN_TRIMMED(grp) \
+ (test_bit(EXT4_GROUP_INFO_HAS_BEEN_TRIMMED, &((grp)->bb_state)))
#define EXT4_MAX_CONTENTION 8
#define EXT4_CONTENTION_THRESHOLD 2
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 4eadac8..3f6b809 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -1563,6 +1563,9 @@ static int mb_mark_used(struct ext4_buddy *e4b, struct ext4_free_extent *ex)
mb_set_bits(EXT4_MB_BITMAP(e4b), ex->fe_start, len0);
mb_check_buddy(e4b);
+ if (!ret)
+ EXT4_SB(sb)->trim_minlen = minlen;
+
return ret;
}
@@ -2687,6 +2690,16 @@ 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))
+ clear_bit(EXT4_GROUP_INFO_HAS_BEEN_TRIMMED,
+ &(db->bb_state));
+
if (!db->bb_free_root.rb_node) {
/* No more items in the per group rb tree
* balance refcounts from ext4_mb_free_metadata()
@@ -4772,6 +4785,10 @@ ext4_grpblk_t ext4_trim_all_free(struct super_block *sb, struct ext4_buddy *e4b,
ext4_lock_group(sb, group);
+ if (EXT4_MB_GRP_HAS_BEEN_TRIMMED(e4b->bd_info) &&
+ minblocks >= EXT4_SB(sb)->trim_minlen)
+ goto out;
+
trace_ext4_trim_all_free(sb, group, start, max);
while (start < max) {
@@ -4804,6 +4821,11 @@ ext4_grpblk_t ext4_trim_all_free(struct super_block *sb, struct ext4_buddy *e4b,
if ((e4b->bd_info->bb_free - free_count) < minblocks)
break;
}
+
+ if (!ret)
+ set_bit(EXT4_GROUP_INFO_HAS_BEEN_TRIMMED,
+ &(e4b->bd_info->bb_state));
+out:
ext4_unlock_group(sb, group);
ext4_debug("trimmed %d blocks in the group %d\n",
--
1.6.3.GIT
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