[PATCH v4 03/17] fs: introduce alloc_inode_sb() to allocate filesystems specific inode
From: Muchun Song <hidden>
Date: 2021-12-13 16:54:48
Also in:
linux-fsdevel, linux-nfs, lkml
Subsystem:
documentation, filesystems (vfs and infrastructure), the rest · Maintainers:
Jonathan Corbet, Alexander Viro, Christian Brauner, Linus Torvalds
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 <redacted> --- Documentation/filesystems/porting.rst | 5 +++++ fs/inode.c | 2 +- include/linux/fs.h | 11 +++++++++++ 3 files changed, 17 insertions(+), 1 deletion(-)
diff --git a/Documentation/filesystems/porting.rst b/Documentation/filesystems/porting.rst
index bf19fd6b86e7..c9c157d7b7bb 100644
--- a/Documentation/filesystems/porting.rst
+++ b/Documentation/filesystems/porting.rst@@ -45,6 +45,11 @@ 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. + --- **mandatory**
diff --git a/fs/inode.c b/fs/inode.c
index 6b80a51129d5..dcb1e6cad201 100644
--- a/fs/inode.c
+++ b/fs/inode.c@@ -234,7 +234,7 @@ 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 bbf812ce89a8..4592f00ec5e7 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h@@ -41,6 +41,7 @@ #include <linux/stddef.h> #include <linux/mount.h> #include <linux/cred.h> +#include <linux/slab.h> #include <asm/byteorder.h> #include <uapi/linux/fs.h>
@@ -3178,6 +3179,16 @@ 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