[PATCH v3 1/4] f2fs: support F2FS_IOC_PRECACHE_EXTENTS

From: Chao Yu
Date: Wed Jan 10 2018 - 05:01:50 EST


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>
---
v3:
- avoid messing up m_next_pgofs updating.
fs/f2fs/data.c | 39 +++++++++++++++++++++++++++++++++++++++
fs/f2fs/f2fs.h | 4 ++++
fs/f2fs/file.c | 44 ++++++++++++++++++++++++++++++++++++++++++--
3 files changed, 85 insertions(+), 2 deletions(-)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 8c05e9a74427..205d6050a3d4 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -861,6 +861,7 @@ int f2fs_preallocate_blocks(struct kiocb *iocb, struct iov_iter *from)
map.m_len = 0;

map.m_next_pgofs = NULL;
+ map.m_next_extent = NULL;
map.m_seg_type = NO_CHECK_TYPE;

if (direct_io) {
@@ -927,6 +928,7 @@ 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 +944,8 @@ 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_extent)
+ *map->m_next_extent = pgofs + map->m_len;
goto out;
}

@@ -960,10 +964,14 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
if (map->m_next_pgofs)
*map->m_next_pgofs =
get_next_page_offset(&dn, pgofs);
+ if (map->m_next_extent)
+ *map->m_next_extent =
+ get_next_page_offset(&dn, pgofs);
}
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 +1005,8 @@ 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 +1065,16 @@ 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 +1084,17 @@ 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_extent)
+ *map->m_next_extent = pgofs + 1;
+ }
f2fs_put_dnode(&dn);
unlock_out:
if (create) {
@@ -1085,6 +1116,7 @@ static int __get_data_block(struct inode *inode, sector_t iblock,
map.m_lblk = iblock;
map.m_len = bh->b_size >> inode->i_blkbits;
map.m_next_pgofs = next_pgofs;
+ map.m_next_extent = NULL;
map.m_seg_type = seg_type;

err = f2fs_map_blocks(inode, &map, create, flag);
@@ -1210,6 +1242,12 @@ 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);
+ if (ret)
+ goto out;
+ }
+
ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC | FIEMAP_FLAG_XATTR);
if (ret)
goto out;
@@ -1309,6 +1347,7 @@ static int f2fs_mpage_readpages(struct address_space *mapping,
map.m_len = 0;
map.m_flags = 0;
map.m_next_pgofs = NULL;
+ map.m_next_extent = NULL;
map.m_seg_type = NO_CHECK_TYPE;

for (; nr_pages; nr_pages--) {
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 3b3ddcdc98e9..aa3cd97c559e 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
@@ -554,6 +555,7 @@ struct f2fs_map_blocks {
unsigned int m_len;
unsigned int m_flags;
pgoff_t *m_next_pgofs; /* point next possible non-hole pgofs */
+ pgoff_t *m_next_extent; /* point to next possible extent */
int m_seg_type;
};

@@ -564,6 +566,7 @@ enum {
F2FS_GET_BLOCK_BMAP,
F2FS_GET_BLOCK_PRE_DIO,
F2FS_GET_BLOCK_PRE_AIO,
+ F2FS_GET_BLOCK_PRECACHE,
};

/*
@@ -2567,6 +2570,7 @@ 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..00b75aa2215c 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1422,7 +1422,7 @@ 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;
@@ -2071,7 +2071,7 @@ 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;
@@ -2734,6 +2734,43 @@ 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 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)))))
@@ -2786,6 +2823,8 @@ 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 +2901,7 @@ 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