Re: [PATCH 3/3] erofs: call erofs_map_dev() inside erofs_map_blocks()

[Gao Xiang]

On 2023/2/3 11:53, Jingbo Xu wrote:

For now erofs_map_blocks() is always followed by erofs_map_dev().
Make erofs_map_dev() called inside erofs_map_blocks() to reduce code
duplication.

Could we just integrate mdev into struct erofs_map_blocks?

BTW, I still think erofs_map_dev() is useful since it can handle
non-inode IO requests, so let's keep this rather than mergeing all
code into erofs_map_blocks()

Thanks,
Gao Xiang

Signed-off-by: Jingbo Xu <jeffl...@linux.alibaba.com>
---
  fs/erofs/data.c     | 21 ++++++++++-----------
  fs/erofs/fscache.c  | 20 ++------------------
  fs/erofs/internal.h |  3 ++-
  3 files changed, 14 insertions(+), 30 deletions(-)

diff --git a/fs/erofs/data.c b/fs/erofs/data.c
index 32e66d29968f..cbe7a6d6846d 100644
--- a/fs/erofs/data.c
+++ b/fs/erofs/data.c
@@ -116,7 +116,8 @@ static int erofs_map_blocks_flatmode(struct inode *inode,
        return 0;
  }

-int erofs_map_blocks(struct inode *inode, struct erofs_map_blocks *map)

+int erofs_map_blocks(struct inode *inode, struct erofs_map_blocks *map,
+                    struct erofs_map_dev *mdev)
  {
        struct super_block *sb = inode->i_sb;
        struct erofs_inode *vi = EROFS_I(inode);
@@ -188,8 +189,14 @@ int erofs_map_blocks(struct inode *inode, struct 
erofs_map_blocks *map)
  out_unlock:
        erofs_put_metabuf(&buf);
  out:
-       if (!err)
+       if (!err) {
                map->m_llen = map->m_plen;
+               *mdev = (struct erofs_map_dev) {
+                       .m_deviceid = map->m_deviceid,
+                       .m_pa = map->m_pa,
+               };
+               err = erofs_map_dev(sb, mdev);
+       }
        trace_erofs_map_blocks_exit(inode, map, EROFS_GET_BLOCKS_RAW, err);
        return err;
  }
@@ -253,15 +260,7 @@ static int erofs_iomap_begin(struct inode *inode, loff_t 
offset, loff_t length,
        map.m_la = offset;
        map.m_llen = length;

- ret = erofs_map_blocks(inode, &map);

-       if (ret < 0)
-               return ret;
-
-       mdev = (struct erofs_map_dev) {
-               .m_deviceid = map.m_deviceid,
-               .m_pa = map.m_pa,
-       };
-       ret = erofs_map_dev(inode->i_sb, &mdev);
+       ret = erofs_map_blocks(inode, &map, &mdev);
        if (ret)
                return ret;

diff --git a/fs/erofs/fscache.c b/fs/erofs/fscache.c

index 7f1ef2ffc4db..140ccacc1043 100644
--- a/fs/erofs/fscache.c
+++ b/fs/erofs/fscache.c
@@ -229,7 +229,7 @@ static int erofs_fscache_data_read_slice(struct 
erofs_fscache_request *primary)
        int ret;

map.m_la = pos;

-       ret = erofs_map_blocks(inode, &map);
+       ret = erofs_map_blocks(inode, &map, &mdev);
        if (ret)
                return ret;

@@ -270,14 +270,6 @@ static int erofs_fscache_data_read_slice(struct erofs_fscache_request *primary)

        count = min_t(size_t, map.m_llen - (pos - map.m_la), count);
        DBG_BUGON(!count || count % PAGE_SIZE);

- mdev = (struct erofs_map_dev) {

-               .m_deviceid = map.m_deviceid,
-               .m_pa = map.m_pa,
-       };
-       ret = erofs_map_dev(sb, &mdev);
-       if (ret)
-               return ret;
-
        req = erofs_fscache_req_chain(primary, count);
        if (IS_ERR(req))
                return PTR_ERR(req);
@@ -377,15 +369,7 @@ static int erofs_fscache_share_file_open(struct inode 
*inode, struct file *filp)
        struct file *realfile;
        int ret;

- ret = erofs_map_blocks(inode, &map);

-       if (ret)
-               return ret;
-
-       mdev = (struct erofs_map_dev) {
-               .m_deviceid = map.m_deviceid,
-               .m_pa = map.m_pa,
-       };
-       ret = erofs_map_dev(inode->i_sb, &mdev);
+       ret = erofs_map_blocks(inode, &map, &mdev);
        if (ret)
                return ret;

diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h

index 323c2c775023..c54dec32a868 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -502,7 +502,8 @@ void *erofs_read_metabuf(struct erofs_buf *buf, struct 
super_block *sb,
  int erofs_map_dev(struct super_block *sb, struct erofs_map_dev *dev);
  int erofs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
                 u64 start, u64 len);
-int erofs_map_blocks(struct inode *inode, struct erofs_map_blocks *map);
+int erofs_map_blocks(struct inode *inode, struct erofs_map_blocks *map,
+                    struct erofs_map_dev *mdev);

/* inode.c */

  static inline unsigned long erofs_inode_hash(erofs_nid_t nid)