[PATCH v6 20/22] erofs: implement fscache-based data read for data blobs

Jeffle Xu
2022-03-25T12:24:42Z

Implements the data plane of reading data from data blob file over
fscache.

Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com>
---
fs/erofs/data.c | 3 +++
fs/erofs/fscache.c | 15 +++++++++++++--
fs/erofs/internal.h | 1 +
3 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/fs/erofs/data.c b/fs/erofs/data.c
index b4571bea93d5..b9a05de3c3b2 100644
--- a/fs/erofs/data.c
+++ b/fs/erofs/data.c
@@ -206,6 +206,7 @@ int erofs_map_dev(struct super_block *sb, struct erofs_map_dev *map)
map->m_bdev = sb->s_bdev;
map->m_daxdev = EROFS_SB(sb)->dax_dev;
map->m_dax_part_off = EROFS_SB(sb)->dax_part_off;
+ map->m_fscache = EROFS_SB(sb)->bootstrap;

if (map->m_deviceid) {
down_read(&devs->rwsem);
@@ -217,6 +218,7 @@ int erofs_map_dev(struct super_block *sb, struct erofs_map_dev *map)
map->m_bdev = dif->bdev;
map->m_daxdev = dif->dax_dev;
map->m_dax_part_off = dif->dax_part_off;
+ map->m_fscache = dif->blob;
up_read(&devs->rwsem);
} else if (devs->extra_devices) {
down_read(&devs->rwsem);
@@ -234,6 +236,7 @@ int erofs_map_dev(struct super_block *sb, struct erofs_map_dev *map)
map->m_bdev = dif->bdev;
map->m_daxdev = dif->dax_dev;
map->m_dax_part_off = dif->dax_part_off;
+ map->m_fscache = dif->blob;
break;
}
}
diff --git a/fs/erofs/fscache.c b/fs/erofs/fscache.c
index d75958470645..cbb39657615e 100644
--- a/fs/erofs/fscache.c
+++ b/fs/erofs/fscache.c
@@ -63,9 +63,20 @@ static int erofs_fscache_readpage_blob(struct file *data, struct page *page)
static inline int erofs_fscache_get_map(struct erofs_map_blocks *map,
struct super_block *sb)
{
- struct erofs_sb_info *sbi = EROFS_SB(sb);
+ struct erofs_map_dev mdev;
+ int ret;
+
+ 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;

- map->m_fscache = sbi->bootstrap;
+ map->m_fscache = mdev.m_fscache;
+ map->m_pa = mdev.m_pa;
return 0;
}

diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index 94a118caf580..cea08f12a2c3 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -487,6 +487,7 @@ struct erofs_map_dev {
struct block_device *m_bdev;
struct dax_device *m_daxdev;
u64 m_dax_part_off;
+ struct erofs_fscache *m_fscache;

erofs_off_t m_pa;
unsigned int m_deviceid;
--
2.27.0