The allocated inode cache is supposed to be added to its memcg list_lru
which should be allocated as well in advance. That can be done by
kmem_cache_alloc_lru() which allocates object and list_lru. The file
systems is main user of it. So introduce alloc_inode_sb() to allocate
file system specific inodes and set up the inode reclaim context
properly. The file system is supposed to use alloc_inode_sb() to
allocate inodes. In the later patches, we will convert all users to the
new API.
Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Reviewed-by: Roman Gushchin <roman.gushchin@xxxxxxxxx>
---
Documentation/filesystems/porting.rst | 6 ++++++
fs/inode.c | 2 +-
include/linux/fs.h | 11 +++++++++++
3 files changed, 18 insertions(+), 1 deletion(-)
diff --git a/Documentation/filesystems/porting.rst b/Documentation/filesystems/porting.rst
index bf19fd6b86e7..7c1583dbeb59 100644
--- a/Documentation/filesystems/porting.rst
+++ b/Documentation/filesystems/porting.rst
@@ -45,6 +45,12 @@ typically between calling iget_locked() and unlocking the inode.
At some point that will become mandatory.
+**mandatory**
+
+The foo_inode_info should always be allocated through alloc_inode_sb() rather
+than kmem_cache_alloc() or kmalloc() related to set up the inode reclaim context
+correctly.
+
---
**mandatory**
diff --git a/fs/inode.c b/fs/inode.c
index 63324df6fa27..9d9b422504d1 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -259,7 +259,7 @@ static struct inode *alloc_inode(struct super_block *sb)
if (ops->alloc_inode)
inode = ops->alloc_inode(sb);
else
- inode = kmem_cache_alloc(inode_cachep, GFP_KERNEL);
+ inode = alloc_inode_sb(sb, inode_cachep, GFP_KERNEL);
if (!inode)
return NULL;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index e2d892b201b0..3d56b02667f4 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -42,6 +42,7 @@
#include <linux/mount.h>
#include <linux/cred.h>
#include <linux/mnt_idmapping.h>
+#include <linux/slab.h>
#include <asm/byteorder.h>
#include <uapi/linux/fs.h>
@@ -3108,6 +3109,16 @@ extern void free_inode_nonrcu(struct inode *inode);
extern int should_remove_suid(struct dentry *);
extern int file_remove_privs(struct file *);
+/*
+ * This must be used for allocating filesystems specific inodes to set
+ * up the inode reclaim context correctly.
+ */
+static inline void *
+alloc_inode_sb(struct super_block *sb, struct kmem_cache *cache, gfp_t gfp)
+{
+ return kmem_cache_alloc_lru(cache, &sb->s_inode_lru, gfp);
+}
+
extern void __insert_inode_hash(struct inode *, unsigned long hashval);
static inline void insert_inode_hash(struct inode *inode)
{
--
2.11.0
