[PATCH 20/25] staging: erofs: introduce superblock registration

Gao Xiang
2018-07-26T12:27:55Z

In order to introducing shrinker solution for erofs,
let's manage all mounted erofs instances at first.

Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
---
drivers/staging/erofs/internal.h | 6 ++++++
drivers/staging/erofs/super.c | 4 ++++
drivers/staging/erofs/utils.c | 17 +++++++++++++++++
3 files changed, 27 insertions(+)

diff --git a/drivers/staging/erofs/internal.h b/drivers/staging/erofs/internal.h
index e61d417..18e7b9c 100644
--- a/drivers/staging/erofs/internal.h
+++ b/drivers/staging/erofs/internal.h
@@ -64,6 +64,9 @@ struct erofs_fault_info {
typedef u64 erofs_nid_t;

struct erofs_sb_info {
+ /* list for all registered superblocks, mainly for shrinker */
+ struct list_head list;
+
u32 blocks;
u32 meta_blkaddr;
#ifdef CONFIG_EROFS_FS_XATTR
@@ -410,6 +413,9 @@ static inline void erofs_vunmap(const void *mem, unsigned int count)
/* utils.c */
extern struct page *erofs_allocpage(struct list_head *pool, gfp_t gfp);

+extern void erofs_register_super(struct super_block *sb);
+extern void erofs_unregister_super(struct super_block *sb);
+
#ifndef lru_to_page
#define lru_to_page(head) (list_entry((head)->prev, struct page, lru))
#endif
diff --git a/drivers/staging/erofs/super.c b/drivers/staging/erofs/super.c
index 054375d..f455d71 100644
--- a/drivers/staging/erofs/super.c
+++ b/drivers/staging/erofs/super.c
@@ -326,6 +326,8 @@ static int erofs_read_super(struct super_block *sb,
snprintf(sbi->dev_name, PATH_MAX, "%s", dev_name);
sbi->dev_name[PATH_MAX - 1] = '\0';

+ erofs_register_super(sb);
+
/*
* We already have a positive dentry, which was instantiated
* by d_make_root. Just need to d_rehash it.
@@ -373,6 +375,8 @@ static void erofs_put_super(struct super_block *sb)
infoln("unmounted for %s", sbi->dev_name);
__putname(sbi->dev_name);

+ erofs_unregister_super(sb);
+
kfree(sbi);
sb->s_fs_info = NULL;
}
diff --git a/drivers/staging/erofs/utils.c b/drivers/staging/erofs/utils.c
index 3dec4f8..6748def 100644
--- a/drivers/staging/erofs/utils.c
+++ b/drivers/staging/erofs/utils.c
@@ -29,3 +29,20 @@ struct page *erofs_allocpage(struct list_head *pool, gfp_t gfp)
return page;
}

+static DEFINE_MUTEX(erofs_sb_list_lock);
+static LIST_HEAD(erofs_sb_list);
+
+void erofs_register_super(struct super_block *sb)
+{
+ mutex_lock(&erofs_sb_list_lock);
+ list_add(&EROFS_SB(sb)->list, &erofs_sb_list);
+ mutex_unlock(&erofs_sb_list_lock);
+}
+
+void erofs_unregister_super(struct super_block *sb)
+{
+ mutex_lock(&erofs_sb_list_lock);
+ list_del(&EROFS_SB(sb)->list);
+ mutex_unlock(&erofs_sb_list_lock);
+}
+
--
1.9.1