Several erofs filesystems can belong to one domain, and data blobs can
be shared among these erofs filesystems of same domain.
Users could specify domain_id mount option to create or join into a domain.
Signed-off-by: Jia Zhu <[email protected]>
---
fs/erofs/domain.c | 60 +++++++++++++++++++++++++++++++++++++++++++++
fs/erofs/fscache.c | 7 ++++++
fs/erofs/internal.h | 13 ++++++++++
fs/erofs/super.c | 10 ++++++--
4 files changed, 88 insertions(+), 2 deletions(-)
diff --git a/fs/erofs/domain.c b/fs/erofs/domain.c
index 6461e4ee3582..ea7b591b7db1 100644
--- a/fs/erofs/domain.c
+++ b/fs/erofs/domain.c
@@ -13,6 +13,66 @@
static DEFINE_SPINLOCK(erofs_domain_list_lock);
static LIST_HEAD(erofs_domain_list);
+static int erofs_fscache_domain_init_cookie(struct super_block *sb,
+ struct erofs_fscache **fscache, char *name, bool need_inode)
+{
+ int ret;
+ struct inode *inode;
+ struct erofs_fscache *ctx;
+ struct erofs_sb_info *sbi = EROFS_SB(sb);
+ struct erofs_domain *domain = sbi->domain;
+
+ ret = erofs_fscache_register_cookie(sb, &ctx, name, need_inode);
+ if (ret)
+ return ret;
+
+ ctx->name = kstrdup(name, GFP_KERNEL);
+ if (!ctx->name)
+ return -ENOMEM;
+
+ inode = new_inode(domain->mnt->mnt_sb);
+ if (!inode) {
+ kfree(ctx->name);
+ return -ENOMEM;
+ }
+
+ ctx->domain = domain;
+ ctx->anon_inode = inode;
+ inode->i_private = ctx;
+ refcount_set(&ctx->ref, 1);
+ erofs_fscache_domain_get(domain);
+ *fscache = ctx;
+ return 0;
+}
+
+int erofs_domain_register_cookie(struct super_block *sb,
+ struct erofs_fscache **fscache, char *name, bool need_inode)
+{
+ int err;
+ struct inode *inode;
+ struct erofs_fscache *ctx;
+ struct erofs_sb_info *sbi = EROFS_SB(sb);
+ struct erofs_domain *domain = sbi->domain;
+ struct super_block *psb = domain->mnt->mnt_sb;
+
+ mutex_lock(&domain->mutex);
+ list_for_each_entry(inode, &psb->s_inodes, i_sb_list) {
+ ctx = inode->i_private;
+ if (!ctx)
+ continue;
+ if (!strcmp(ctx->name, name)) {
+ *fscache = ctx;
+ refcount_inc(&ctx->ref);
+ mutex_unlock(&domain->mutex);
+ return 0;
+ }
+ }
+ err = erofs_fscache_domain_init_cookie(sb, fscache, name, need_inode);
+ mutex_unlock(&domain->mutex);
+
+ return err;
+}
+
void erofs_fscache_domain_get(struct erofs_domain *domain)
{
if (!domain)
diff --git a/fs/erofs/fscache.c b/fs/erofs/fscache.c
index 5c918a06ae9a..51425e310e3d 100644
--- a/fs/erofs/fscache.c
+++ b/fs/erofs/fscache.c
@@ -476,6 +476,8 @@ void erofs_fscache_unregister_cookie(struct erofs_fscache **fscache)
if (!ctx)
return;
+ if (ctx->domain && !refcount_dec_and_test(&ctx->ref))
+ return;
fscache_unuse_cookie(ctx->cookie, NULL, NULL);
fscache_relinquish_cookie(ctx->cookie, false);
@@ -483,7 +485,12 @@ void erofs_fscache_unregister_cookie(struct erofs_fscache **fscache)
iput(ctx->inode);
ctx->inode = NULL;
+ iput(ctx->anon_inode);
+ ctx->anon_inode = NULL;
+ erofs_fscache_domain_put(ctx->domain);
+ kfree(ctx->name);
+ ctx->name = NULL;
kfree(ctx);
*fscache = NULL;
}
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index bca4e9c57890..1abdad81bfe3 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -109,8 +109,12 @@ struct erofs_domain {
};
struct erofs_fscache {
+ refcount_t ref;
struct fscache_cookie *cookie;
struct inode *inode;
+ struct inode *anon_inode;
+ struct erofs_domain *domain;
+ char *name;
};
struct erofs_sb_info {
@@ -627,6 +631,9 @@ int erofs_fscache_register_domain(struct super_block *sb);
int erofs_fscache_register_cookie(struct super_block *sb,
struct erofs_fscache **fscache,
char *name, bool need_inode);
+int erofs_domain_register_cookie(struct super_block *sb,
+ struct erofs_fscache **fscache,
+ char *name, bool need_inode);
void erofs_fscache_unregister_cookie(struct erofs_fscache **fscache);
extern const struct address_space_operations erofs_fscache_access_aops;
@@ -648,6 +655,12 @@ static inline int erofs_fscache_register_cookie(struct super_block *sb,
{
return -EOPNOTSUPP;
}
+static inline int erofs_domain_register_cookie(struct super_block *sb,
+ struct erofs_fscache **fscache,
+ char *name, bool need_inode)
+{
+ return -EOPNOTSUPP;
+}
static inline void erofs_fscache_unregister_cookie(struct erofs_fscache **fscache)
{
diff --git a/fs/erofs/super.c b/fs/erofs/super.c
index bbc63b7d546c..aefe7dfcd4c9 100644
--- a/fs/erofs/super.c
+++ b/fs/erofs/super.c
@@ -245,8 +245,12 @@ static int erofs_init_device(struct erofs_buf *buf, struct super_block *sb,
}
if (erofs_is_fscache_mode(sb)) {
- ret = erofs_fscache_register_cookie(sb, &dif->fscache,
- dif->path, false);
+ if (sbi->opt.domain_id)
+ ret = erofs_domain_register_cookie(sb, &dif->fscache, dif->path,
+ false);
+ else
+ ret = erofs_fscache_register_cookie(sb, &dif->fscache, dif->path,
+ false);
if (ret)
return ret;
} else {
@@ -719,6 +723,8 @@ static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc)
err = erofs_fscache_register_domain(sb);
if (err)
return err;
+ err = erofs_domain_register_cookie(sb, &sbi->s_fscache,
+ sbi->opt.fsid, true);
} else {
err = erofs_fscache_register_fs(sb);
if (err)
--
2.20.1