[PATCH v4 19/21] erofs: implement fscache-based data read for data blobs

Jeffle Xu
2022-03-07T12:34:48Z

This patch 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 | 16 +++++++++++++---
fs/erofs/internal.h | 1 +
3 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/fs/erofs/data.c b/fs/erofs/data.c
index 1bff99576883..c5ccf55c050c 100644
--- a/fs/erofs/data.c
+++ b/fs/erofs/data.c
@@ -200,6 +200,7 @@ 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_ctx = EROFS_SB(sb)->bootstrap;

if (map->m_deviceid) {
down_read(&devs->rwsem);
@@ -211,6 +212,7 @@ 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_ctx = dif->ctx;
up_read(&devs->rwsem);
} else if (devs->extra_devices) {
down_read(&devs->rwsem);
@@ -228,6 +230,7 @@ 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_ctx = dif->ctx;
break;
}
}
diff --git a/fs/erofs/fscache.c b/fs/erofs/fscache.c
index 4da148cc4484..89c533ad965e 100644
--- a/fs/erofs/fscache.c
+++ b/fs/erofs/fscache.c
@@ -70,11 +70,21 @@ static inline int erofs_fscache_get_map(struct erofs_fscache_map *fsmap,
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;

- fsmap->m_ctx = sbi->bootstrap;
+ fsmap->m_ctx = mdev.m_ctx;
+ fsmap->m_pa = mdev.m_pa;
fsmap->m_la = map->m_la;
- fsmap->m_pa = map->m_pa;
fsmap->m_llen = map->m_llen;

return 0;
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index 5d514c7b73cc..6ccf14952b2d 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -486,6 +486,7 @@ struct erofs_map_dev {
struct block_device *m_bdev;
struct dax_device *m_daxdev;
u64 m_dax_part_off;
+ struct erofs_fscache_context *m_ctx;

erofs_off_t m_pa;
unsigned int m_deviceid;
--
2.27.0