From 79344efb93a26378a91193bed133cee42162cd81 Mon Sep 17 00:00:00 2001
From: Jaegeuk Kim <jaegeuk@kernel.org>
Date: Fri, 6 May 2016 16:19:43 -0700
Subject: f2fs: read node blocks ahead when truncating blocks
This patch enables reading node blocks in advance when truncating large
data blocks.
> time rm $MNT/testfile (500GB) after drop_cachees
Before : 9.422 s
After : 4.821 s
Reported-by: Stephen Bates <stephen.bates@microsemi.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
fs/f2fs/node.c | 52 ++++++++++++++++++++++++++++------------------------
1 file changed, 28 insertions(+), 24 deletions(-)
(limited to 'fs/f2fs/node.c')
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 264abe08bafb..cda7c7ccd4c8 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -407,6 +407,29 @@ cache:
up_write(&nm_i->nat_tree_lock);
}
+/*
+ * readahead MAX_RA_NODE number of node pages.
+ */
+static void ra_node_pages(struct page *parent, int start, int n)
+{
+ struct f2fs_sb_info *sbi = F2FS_P_SB(parent);
+ struct blk_plug plug;
+ int i, end;
+ nid_t nid;
+
+ blk_start_plug(&plug);
+
+ /* Then, try readahead for siblings of the desired node */
+ end = start + n;
+ end = min(end, NIDS_PER_BLOCK);
+ for (i = start; i < end; i++) {
+ nid = get_nid(parent, i, false);
+ ra_node_page(sbi, nid);
+ }
+
+ blk_finish_plug(&plug);
+}
+
pgoff_t get_next_page_offset(struct dnode_of_data *dn, pgoff_t pgofs)
{
const long direct_index = ADDRS_PER_INODE(dn->inode);
@@ -707,6 +730,8 @@ static int truncate_nodes(struct dnode_of_data *dn, unsigned int nofs,
return PTR_ERR(page);
}
+ ra_node_pages(page, ofs, NIDS_PER_BLOCK);
+
rn = F2FS_NODE(page);
if (depth < 3) {
for (i = ofs; i < NIDS_PER_BLOCK; i++, freed++) {
@@ -784,6 +809,8 @@ static int truncate_partial_nodes(struct dnode_of_data *dn,
nid[i + 1] = get_nid(pages[i], offset[i + 1], false);
}
+ ra_node_pages(pages[idx], offset[idx + 1], NIDS_PER_BLOCK);
+
/* free direct nodes linked to a partial indirect node */
for (i = offset[idx + 1]; i < NIDS_PER_BLOCK; i++) {
child_nid = get_nid(pages[idx], i, false);
@@ -1095,29 +1122,6 @@ void ra_node_page(struct f2fs_sb_info *sbi, nid_t nid)
f2fs_put_page(apage, err ? 1 : 0);
}
-/*
- * readahead MAX_RA_NODE number of node pages.
- */
-static void ra_node_pages(struct page *parent, int start)
-{
- struct f2fs_sb_info *sbi = F2FS_P_SB(parent);
- struct blk_plug plug;
- int i, end;
- nid_t nid;
-
- blk_start_plug(&plug);
-
- /* Then, try readahead for siblings of the desired node */
- end = start + MAX_RA_NODE;
- end = min(end, NIDS_PER_BLOCK);
- for (i = start; i < end; i++) {
- nid = get_nid(parent, i, false);
- ra_node_page(sbi, nid);
- }
-
- blk_finish_plug(&plug);
-}
-
static struct page *__get_node_page(struct f2fs_sb_info *sbi, pgoff_t nid,
struct page *parent, int start)
{
@@ -1141,7 +1145,7 @@ repeat:
}
if (parent)
- ra_node_pages(parent, start + 1);
+ ra_node_pages(parent, start + 1, MAX_RA_NODE);
lock_page(page);
--
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