Introduce one anonymous inode managing page cache for data blob. Then
erofs could read directly from the address space of the anonymous inode
when cache hit.
Signed-off-by: Jeffle Xu <jeffl...@linux.alibaba.com>
---
fs/erofs/fscache.c | 39 ++++++++++++++++++++++++++++++++++++---
fs/erofs/internal.h | 6 ++++--
2 files changed, 40 insertions(+), 5 deletions(-)
diff --git a/fs/erofs/fscache.c b/fs/erofs/fscache.c
index 67a3c4935245..1c88614203d2 100644
--- a/fs/erofs/fscache.c
+++ b/fs/erofs/fscache.c
@@ -5,17 +5,22 @@
#include <linux/fscache.h>
#include "internal.h"
+static const struct address_space_operations erofs_fscache_meta_aops = {
+};
+
/*
* Create an fscache context for data blob.
* Return: 0 on success and allocated fscache context is assigned to @fscache,
* negative error number on failure.
*/
int erofs_fscache_register_cookie(struct super_block *sb,
- struct erofs_fscache **fscache, char *name)
+ struct erofs_fscache **fscache,
+ char *name, bool need_inode)
{
struct fscache_volume *volume = EROFS_SB(sb)->volume;
struct erofs_fscache *ctx;
struct fscache_cookie *cookie;
+ int ret;
ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
if (!ctx)
@@ -25,15 +30,40 @@ int erofs_fscache_register_cookie(struct super_block *sb,
name, strlen(name), NULL, 0, 0);
if (!cookie) {
erofs_err(sb, "failed to get cookie for %s", name);
- kfree(name);
- return -EINVAL;
+ ret = -EINVAL;
+ goto err;
}
fscache_use_cookie(cookie, false);
ctx->cookie = cookie;
+ if (need_inode) {
+ struct inode *const inode = new_inode(sb);
+
+ if (!inode) {
+ erofs_err(sb, "failed to get anon inode for %s", name);
+ ret = -ENOMEM;
+ goto err_cookie;
+ }
+
+ set_nlink(inode, 1);
+ inode->i_size = OFFSET_MAX;
+ inode->i_mapping->a_ops = &erofs_fscache_meta_aops;
+ mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS);
+
+ ctx->inode = inode;
+ }
+
*fscache = ctx;
return 0;
+
+err_cookie:
+ fscache_unuse_cookie(ctx->cookie, NULL, NULL);
+ fscache_relinquish_cookie(ctx->cookie, false);
+ ctx->cookie = NULL;
+err:
+ kfree(ctx);
+ return ret;
}
void erofs_fscache_unregister_cookie(struct erofs_fscache **fscache)
@@ -47,6 +77,9 @@ void erofs_fscache_unregister_cookie(struct erofs_fscache
**fscache)
fscache_relinquish_cookie(ctx->cookie, false);
ctx->cookie = NULL;
+ iput(ctx->inode);
+ ctx->inode = NULL;
+
kfree(ctx);
*fscache = NULL;
}
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index c6a3351a4d7d..3a4a344cfed3 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -99,6 +99,7 @@ struct erofs_sb_lz4_info {
struct erofs_fscache {
struct fscache_cookie *cookie;
+ struct inode *inode;
};
struct erofs_sb_info {
@@ -632,7 +633,8 @@ int erofs_fscache_register_fs(struct super_block *sb);
void erofs_fscache_unregister_fs(struct super_block *sb);
int erofs_fscache_register_cookie(struct super_block *sb,
- struct erofs_fscache **fscache, char *name);
+ struct erofs_fscache **fscache,
+ char *name, bool need_inode);
void erofs_fscache_unregister_cookie(struct erofs_fscache **fscache);
#else
static inline int erofs_fscache_register_fs(struct super_block *sb) { return
0; }
@@ -640,7 +642,7 @@ static inline void erofs_fscache_unregister_fs(struct
super_block *sb) {}
static inline int erofs_fscache_register_cookie(struct super_block *sb,
struct erofs_fscache **fscache,
- char *name)
+ char *name, bool need_inode)
{
return -EOPNOTSUPP;
}
--
2.27.0
--
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