f2fs: support F2FS_IOC_PRECACHE_EXTENTS

This patch introduces a new ioctl F2FS_IOC_PRECACHE_EXTENTS to precache
extent info like ext4, in order to gain better performance during
triggering AIO by eliminating synchronous waiting of mapping info.

Referred commit: 7869a4a6c5ca ("ext4: add support for extent pre-caching")

In addition, with newly added extent precache abilitiy, this patch add
to support FIEMAP_FLAG_CACHE in ->fiemap.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

1 files changed, 42 insertions, 2 deletions

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 493457a200b1..58c9e3d8b8ec 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1423,7 +1423,7 @@ static int expand_inode_data(struct inode *inode, loff_t offset,
 {
 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 	struct f2fs_map_blocks map = { .m_next_pgofs = NULL,
-					.m_seg_type = NO_CHECK_TYPE };
+			.m_next_extent = NULL, .m_seg_type = NO_CHECK_TYPE };
 	pgoff_t pg_end;
 	loff_t new_size = i_size_read(inode);
 	loff_t off_end;
@@ -2072,7 +2072,7 @@ static int f2fs_defragment_range(struct f2fs_sb_info *sbi,
 {
 	struct inode *inode = file_inode(filp);
 	struct f2fs_map_blocks map = { .m_next_pgofs = NULL,
-					.m_seg_type = NO_CHECK_TYPE };
+			.m_next_extent = NULL, .m_seg_type = NO_CHECK_TYPE };
 	struct extent_info ei = {0,0,0};
 	pgoff_t pg_start, pg_end;
 	unsigned int blk_per_seg = sbi->blocks_per_seg;
@@ -2749,6 +2749,43 @@ static int f2fs_ioc_get_pin_file(struct file *filp, unsigned long arg)
 	return put_user(pin, (u32 __user *)arg);
 }
 
+int f2fs_precache_extents(struct inode *inode)
+{
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	struct f2fs_map_blocks map;
+	pgoff_t m_next_extent;
+	loff_t end;
+	int err;
+
+	if (is_inode_flag_set(inode, FI_NO_EXTENT))
+		return -EOPNOTSUPP;
+
+	map.m_lblk = 0;
+	map.m_next_pgofs = NULL;
+	map.m_next_extent = &m_next_extent;
+	map.m_seg_type = NO_CHECK_TYPE;
+	end = F2FS_I_SB(inode)->max_file_blocks;
+
+	while (map.m_lblk < end) {
+		map.m_len = end - map.m_lblk;
+
+		down_write(&fi->dio_rwsem[WRITE]);
+		err = f2fs_map_blocks(inode, &map, 0, F2FS_GET_BLOCK_PRECACHE);
+		up_write(&fi->dio_rwsem[WRITE]);
+		if (err)
+			return err;
+
+		map.m_lblk = m_next_extent;
+	}
+
+	return err;
+}
+
+static int f2fs_ioc_precache_extents(struct file *filp, unsigned long arg)
+{
+	return f2fs_precache_extents(file_inode(filp));
+}
+
 long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
 	if (unlikely(f2fs_cp_error(F2FS_I_SB(file_inode(filp)))))
@@ -2803,6 +2840,8 @@ long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 		return f2fs_ioc_get_pin_file(filp, arg);
 	case F2FS_IOC_SET_PIN_FILE:
 		return f2fs_ioc_set_pin_file(filp, arg);
+	case F2FS_IOC_PRECACHE_EXTENTS:
+		return f2fs_ioc_precache_extents(filp, arg);
 	default:
 		return -ENOTTY;
 	}
@@ -2880,6 +2919,7 @@ long f2fs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	case F2FS_IOC_FSSETXATTR:
 	case F2FS_IOC_GET_PIN_FILE:
 	case F2FS_IOC_SET_PIN_FILE:
+	case F2FS_IOC_PRECACHE_EXTENTS:
 		break;
 	default:
 		return -ENOIOCTLCMD;