Re: [PATCH v2 1/4] f2fs: support F2FS_IOC_PRECACHE_EXTENTS
From: Chao Yu
Date: Wed Jan 10 2018 - 20:27:17 EST
On 2018/1/11 3:24, Jaegeuk Kim wrote:
> On 01/10, Chao Yu wrote:
>> 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@xxxxxxxxxx>
>> ---
>> v2:
>> - integrate extent precache related patches into this one.
>> fs/f2fs/data.c | 33 +++++++++++++++++++++++++++++++++
>> fs/f2fs/f2fs.h | 3 +++
>> fs/f2fs/file.c | 39 +++++++++++++++++++++++++++++++++++++++
>> 3 files changed, 75 insertions(+)
>>
>> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
>> index 8c05e9a74427..d7d3b2b49907 100644
>> --- a/fs/f2fs/data.c
>> +++ b/fs/f2fs/data.c
>> @@ -927,6 +927,7 @@ 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;
>> @@ -942,6 +943,8 @@ 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;
>> }
>>
>> @@ -964,6 +967,7 @@ 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);
>> @@ -997,6 +1001,8 @@ 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)
>> @@ -1055,6 +1061,16 @@ 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) {
>> @@ -1064,6 +1080,17 @@ 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) {
>> @@ -1210,6 +1237,12 @@ int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
>>
>> inode_lock(inode);
>>
>> + if (fieinfo->fi_flags & FIEMAP_FLAG_CACHE) {
>> + ret = f2fs_precache_extents(inode);
>
> We need to do inode_lock() in f2fs_precache_extents() after uncovering here?
> Uh? We don't need to cover fiemap_check_flags() by inode_lock().
Hmm, how about just following generic_block_fiemap using inode lock to
cover whole block_fiemap including fiemap_check_flags, that can avoid
leaving a hole in f2fs_fiemap after we add f2fs_precache_extents before
fiemap_check_flags.
Thanks,
>
>> + if (ret)
>> + goto out;
>> + }
>> +
>> ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC | FIEMAP_FLAG_XATTR);
>> if (ret)
>> goto out;
>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
>> index 3b3ddcdc98e9..73a751cdbac1 100644
>> --- a/fs/f2fs/f2fs.h
>> +++ b/fs/f2fs/f2fs.h
>> @@ -359,6 +359,7 @@ 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
>> @@ -564,6 +565,7 @@ enum {
>> F2FS_GET_BLOCK_BMAP,
>> F2FS_GET_BLOCK_PRE_DIO,
>> F2FS_GET_BLOCK_PRE_AIO,
>> + F2FS_GET_BLOCK_PRECACHE,
>> };
>>
>> /*
>> @@ -2567,6 +2569,7 @@ int f2fs_getattr(const struct path *path, struct kstat *stat,
>> int f2fs_setattr(struct dentry *dentry, struct iattr *attr);
>> int truncate_hole(struct inode *inode, pgoff_t pg_start, pgoff_t pg_end);
>> void truncate_data_blocks_range(struct dnode_of_data *dn, int count);
>> +int f2fs_precache_extents(struct inode *inode);
>> long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg);
>> long f2fs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
>> int f2fs_pin_file_control(struct inode *inode, bool inc);
>> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
>> index e4078b32856c..6e30016f26ad 100644
>> --- a/fs/f2fs/file.c
>> +++ b/fs/f2fs/file.c
>> @@ -2734,6 +2734,42 @@ static int f2fs_ioc_set_pin_file(struct file *filp, unsigned long arg)
>> return ret;
>> }
>>
>> +int f2fs_precache_extents(struct inode *inode)
>> +{
>> + 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 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)))))
>> @@ -2786,6 +2822,8 @@ 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 +2900,7 @@ 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
>
> .
>