[PATCH 1/4] f2fs: support F2FS_IOC_PRECACHE_EXTENTS

[Chao Yu]

This patch introduces a new ioctl F2FS_IOC_PRECACHE_EXTENTS to precache
extent info, in order to gain better performance during data/meta
accessing.

Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
---
 fs/f2fs/data.c | 27 +++++++++++++++++++++++++++
 fs/f2fs/f2fs.h |  2 ++
 fs/f2fs/file.c | 35 +++++++++++++++++++++++++++++++++++
 3 files changed, 64 insertions(+)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 429764118604..f38e660bc889 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -920,6 +920,7 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
 	blkcnt_t prealloc;
 	struct extent_info ei = {0,0,0};
 	block_t blkaddr;
+	unsigned int start_pgofs;
 
 	if (!maxblocks)
 		return 0;
@@ -935,6 +936,8 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
 		map->m_pblk = ei.blk + pgofs - ei.fofs;
 		map->m_len = min((pgoff_t)maxblocks, ei.fofs + ei.len - pgofs);
 		map->m_flags = F2FS_MAP_MAPPED;
+		if (map->m_next_pgofs)
+			*map->m_next_pgofs = pgofs + map->m_len;
 		goto out;
 	}
 
@@ -957,6 +960,7 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
 		goto unlock_out;
 	}
 
+	start_pgofs = pgofs;
 	prealloc = 0;
 	last_ofs_in_node = ofs_in_node = dn.ofs_in_node;
 	end_offset = ADDRS_PER_PAGE(dn.node_page, inode);
@@ -990,6 +994,8 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
 				map->m_pblk = 0;
 				goto sync_out;
 			}
+			if (flag == F2FS_GET_BLOCK_PRECACHE)
+				goto sync_out;
 			if (flag == F2FS_GET_BLOCK_FIEMAP &&
 						blkaddr == NULL_ADDR) {
 				if (map->m_next_pgofs)
@@ -1048,6 +1054,16 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
 	else if (dn.ofs_in_node < end_offset)
 		goto next_block;
 
+	if (flag == F2FS_GET_BLOCK_PRECACHE) {
+		if (map->m_flags & F2FS_MAP_MAPPED) {
+			unsigned int ofs = start_pgofs - map->m_lblk;
+
+			f2fs_update_extent_cache_range(&dn,
+				start_pgofs, map->m_pblk + ofs,
+				map->m_len - ofs);
+		}
+	}
+
 	f2fs_put_dnode(&dn);
 
 	if (create) {
@@ -1057,6 +1073,17 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
 	goto next_dnode;
 
 sync_out:
+	if (flag == F2FS_GET_BLOCK_PRECACHE) {
+		if (map->m_flags & F2FS_MAP_MAPPED) {
+			unsigned int ofs = start_pgofs - map->m_lblk;
+
+			f2fs_update_extent_cache_range(&dn,
+				start_pgofs, map->m_pblk + ofs,
+				map->m_len - ofs);
+		}
+		if (map->m_next_pgofs)
+			*map->m_next_pgofs = pgofs + 1;
+	}
 	f2fs_put_dnode(&dn);
 unlock_out:
 	if (create) {
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 2f097139b8f7..14177cebc3e7 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -353,6 +353,7 @@ static inline bool __has_cursum_space(struct f2fs_journal *journal,
 						struct f2fs_gc_range)
 #define F2FS_IOC_GET_FEATURES		_IOR(F2FS_IOCTL_MAGIC, 12, __u32)
 #define F2FS_IOC_SET_PIN_FILE		_IOW(F2FS_IOCTL_MAGIC, 13, __u32)
+#define F2FS_IOC_PRECACHE_EXTENTS	_IO(F2FS_IOCTL_MAGIC, 14)
 
 #define F2FS_IOC_SET_ENCRYPTION_POLICY	FS_IOC_SET_ENCRYPTION_POLICY
 #define F2FS_IOC_GET_ENCRYPTION_POLICY	FS_IOC_GET_ENCRYPTION_POLICY
@@ -558,6 +559,7 @@ enum {
 	F2FS_GET_BLOCK_BMAP,
 	F2FS_GET_BLOCK_PRE_DIO,
 	F2FS_GET_BLOCK_PRE_AIO,
+	F2FS_GET_BLOCK_PRECACHE,
 };
 
 /*
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index e4078b32856c..14e75871acf3 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -2734,6 +2734,38 @@ static int f2fs_ioc_set_pin_file(struct file *filp, unsigned long arg)
 	return ret;
 }
 
+static int f2fs_ioc_precache_extents(struct file *filp, unsigned long arg)
+{
+	struct inode *inode = file_inode(filp);
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	struct f2fs_map_blocks map;
+	pgoff_t next_pgofs;
+	loff_t end;
+	int err;
+
+	if (is_inode_flag_set(inode, FI_NO_EXTENT))
+		return -EOPNOTSUPP;
+
+	map.m_lblk = 0;
+	map.m_next_pgofs = &next_pgofs;
+	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 = next_pgofs;
+	}
+
+	return 0;
+}
+
 long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
 	if (unlikely(f2fs_cp_error(F2FS_I_SB(file_inode(filp)))))
@@ -2786,6 +2818,8 @@ long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 		return f2fs_ioc_fssetxattr(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;
 	}
@@ -2862,6 +2896,7 @@ long f2fs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	case F2FS_IOC_FSGETXATTR:
 	case F2FS_IOC_FSSETXATTR:
 	case F2FS_IOC_SET_PIN_FILE:
+	case F2FS_IOC_PRECACHE_EXTENTS:
 		break;
 	default:
 		return -ENOIOCTLCMD;
-- 
2.15.0.55.gc2ece9dc4de6