[PATCH v4 4/4] f2fs: Optimize f2fs_truncate_data_blocks_range()

[Yi Sun]

Function f2fs_invalidate_blocks() can process continuous
blocks at a time, so f2fs_truncate_data_blocks_range() is
optimized to use the new functionality of
f2fs_invalidate_blocks().

Signed-off-by: Yi Sun <yi.sun@xxxxxxxxxx>
---
 fs/f2fs/file.c | 72 +++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 68 insertions(+), 4 deletions(-)

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 81764b10840b..9980d17ef9f5 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -612,6 +612,15 @@ static int f2fs_file_open(struct inode *inode, struct file *filp)
 	return finish_preallocate_blocks(inode);
 }
 
+static bool check_curr_block_is_consecutive(struct f2fs_sb_info *sbi,
+					block_t curr, block_t end)
+{
+	if (curr - end == 1 || curr == end)
+		return true;
+	else
+		return false;
+}
+
 void f2fs_truncate_data_blocks_range(struct dnode_of_data *dn, int count)
 {
 	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
@@ -621,8 +630,27 @@ void f2fs_truncate_data_blocks_range(struct dnode_of_data *dn, int count)
 	int cluster_index = 0, valid_blocks = 0;
 	int cluster_size = F2FS_I(dn->inode)->i_cluster_size;
 	bool released = !atomic_read(&F2FS_I(dn->inode)->i_compr_blocks);
+	/*
+	 * Temporary record location.
+	 * When the current  @blkaddr and @blkaddr_end can be processed
+	 * together, update the value of @blkaddr_end.
+	 * When it is detected that current @blkaddr is not continues with
+	 * @blkaddr_end, it is necessary to process continues blocks
+	 * range [blkaddr_start, blkaddr_end].
+	 */
+	block_t blkaddr_start, blkaddr_end;
+	/*.
+	 * To avoid processing various invalid data blocks.
+	 * Because @blkaddr_start and @blkaddr_end may be assigned
+	 * NULL_ADDR or invalid data blocks, @last_valid is used to
+	 * record this situation.
+	 */
+	bool last_valid = false;
+	/* Process the last @blkaddr separately? */
+	bool last_one = true;
 
 	addr = get_dnode_addr(dn->inode, dn->node_page) + ofs;
+	blkaddr_start = blkaddr_end = le32_to_cpu(*addr);
 
 	/* Assumption: truncation starts with cluster */
 	for (; count > 0; count--, addr++, dn->ofs_in_node++, cluster_index++) {
@@ -638,24 +666,60 @@ void f2fs_truncate_data_blocks_range(struct dnode_of_data *dn, int count)
 		}
 
 		if (blkaddr == NULL_ADDR)
-			continue;
+			goto next;
 
 		f2fs_set_data_blkaddr(dn, NULL_ADDR);
 
 		if (__is_valid_data_blkaddr(blkaddr)) {
 			if (time_to_inject(sbi, FAULT_BLKADDR_CONSISTENCE))
-				continue;
+				goto next;
 			if (!f2fs_is_valid_blkaddr_raw(sbi, blkaddr,
 						DATA_GENERIC_ENHANCE))
-				continue;
+				goto next;
 			if (compressed_cluster)
 				valid_blocks++;
 		}
 
-		f2fs_invalidate_blocks(sbi, blkaddr, 1);
+
+		if (check_curr_block_is_consecutive(sbi, blkaddr, blkaddr_end)) {
+			/*
+			 * The current block @blkaddr is continuous with
+			 * @blkaddr_end, so @blkaddr_end is updated.
+			 * And the f2fs_invalidate_blocks() is skipped
+			 * until @blkaddr that cannot be processed
+			 * together is encountered.
+			 */
+			blkaddr_end = blkaddr;
+			if (count == 1)
+				last_one = false;
+			else
+				goto skip_invalid;
+		}
+
+		f2fs_invalidate_blocks(sbi, blkaddr_start,
+					blkaddr_end - blkaddr_start + 1);
+		blkaddr_start = blkaddr_end = blkaddr;
+
+		if (count == 1 && last_one)
+			f2fs_invalidate_blocks(sbi, blkaddr, 1);
+
+skip_invalid:
+		last_valid = true;
 
 		if (!released || blkaddr != COMPRESS_ADDR)
 			nr_free++;
+
+		continue;
+
+next:
+		/* If consecutive blocks have been recorded, we need to process them. */
+		if (last_valid == true)
+			f2fs_invalidate_blocks(sbi, blkaddr_start,
+					blkaddr_end - blkaddr_start + 1);
+
+		blkaddr_start = blkaddr_end = le32_to_cpu(*(addr + 1));
+		last_valid = false;
+
 	}
 
 	if (compressed_cluster)
-- 
2.25.1