On 01/08, Chao Yu wrote:
> 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 <yuch...@huawei.com>
> ---
> 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:
It looks like F2FS_IOC_CACHE_EXTENTS, and would be better to have an offset
range to look up. BTW, if this is to prepare coming data reads, how about doing
this through fadvise(POSIX_FADV_WILLNEED) instead of additional ioctl?
It seems we can cache extents if the page is marked as PageReadahead().
Thanks,
> + 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
