On Wed, Sep 14, 2022 at 06:50:41PM +0800, Jia Zhu wrote:
> 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/fscache.c | 89 +++++++++++++++++++++++++++++++++++++++++++--
> fs/erofs/internal.h | 4 +-
> 2 files changed, 89 insertions(+), 4 deletions(-)
>
> diff --git a/fs/erofs/fscache.c b/fs/erofs/fscache.c
> index 4e0a441afb7d..e9ae1ee963e2 100644
> --- a/fs/erofs/fscache.c
> +++ b/fs/erofs/fscache.c
> @@ -7,6 +7,7 @@
> #include "internal.h"
>
> static DEFINE_MUTEX(erofs_domain_list_lock);
> +static DEFINE_MUTEX(erofs_domain_cookies_lock);
> static LIST_HEAD(erofs_domain_list);
> static struct vfsmount *erofs_pseudo_mnt;
>
> @@ -504,7 +505,6 @@ static int erofs_fscache_init_domain(struct super_block
> *sb)
>
> domain->volume = sbi->volume;
> refcount_set(&domain->ref, 1);
> - mutex_init(&domain->mutex);
> list_add(&domain->list, &erofs_domain_list);
> return 0;
> out:
> @@ -534,8 +534,8 @@ static int erofs_fscache_register_domain(struct
> super_block *sb)
> return err;
> }
>
> -struct erofs_fscache *erofs_fscache_register_cookie(struct super_block *sb,
> - char *name, bool
> need_inode)
> +struct erofs_fscache *erofs_fscache_acquire_cookie(struct super_block *sb,
> + char *name, bool need_inode)
> {
> struct fscache_volume *volume = EROFS_SB(sb)->volume;
> struct erofs_fscache *ctx;
> @@ -585,13 +585,96 @@ struct erofs_fscache
> *erofs_fscache_register_cookie(struct super_block *sb,
> return ERR_PTR(ret);
> }
>
> +static
> +struct erofs_fscache *erofs_fscache_domain_init_cookie(struct super_block
> *sb,
> + char *name, bool
> need_inode)
> +{
> + struct inode *inode;
> + struct erofs_fscache *ctx;
> + struct erofs_sb_info *sbi = EROFS_SB(sb);
> + struct erofs_domain *domain = sbi->domain;
struct erofs_domain *domain = EROFS_SB(sb)->domain;
> +
> + ctx = erofs_fscache_acquire_cookie(sb, name, need_inode);
> + if (IS_ERR(ctx))
> + return ctx;
> +
> + ctx->name = kstrdup(name, GFP_KERNEL);
> + if (!ctx->name)
> + return ERR_PTR(-ENOMEM);
> +
> + inode = new_inode(erofs_pseudo_mnt->mnt_sb);
> + if (!inode) {
> + kfree(ctx->name);
> + return ERR_PTR(-ENOMEM);
> + }
> +
> + ctx->domain = domain;
> + ctx->anon_inode = inode;
> + inode->i_private = ctx;
> + erofs_fscache_domain_get(domain);
> + return ctx;
> +}
> +
> +static
> +struct erofs_fscache *erofs_domain_register_cookie(struct super_block *sb,
> + char *name, bool need_inode)
> +{
> + struct inode *inode;
> + struct erofs_fscache *ctx;
> + struct erofs_sb_info *sbi = EROFS_SB(sb);
> + struct erofs_domain *domain = sbi->domain;
struct erofs_domain *domain = EROFS_SB(sb)->domain;
> + struct super_block *psb = erofs_pseudo_mnt->mnt_sb;
> +
> + mutex_lock(&erofs_domain_cookies_lock);
> + list_for_each_entry(inode, &psb->s_inodes, i_sb_list) {
> + ctx = inode->i_private;
> + if (!ctx)
> + continue;
> + if (ctx->domain == domain && !strcmp(ctx->name, name)) {
> + igrab(inode);
> + mutex_unlock(&erofs_domain_cookies_lock);
> + return ctx;
> + }
if (!ctx || ctx->domain != domain ||
strcmp(ctx->name, name))
continue;
igrab(inode);
mutex_unlock(&erofs_domain_cookies_lock);
return ctx;
> + }
> + ctx = erofs_fscache_domain_init_cookie(sb, name, need_inode);
> + mutex_unlock(&erofs_domain_cookies_lock);
> + return ctx;
> +}
> +
> +struct erofs_fscache *erofs_fscache_register_cookie(struct super_block *sb,
> + char *name, bool
> need_inode)
> +{
> + struct erofs_sb_info *sbi = EROFS_SB(sb);
> +
> + if (sbi->opt.domain_id)
> + return erofs_domain_register_cookie(sb, name, need_inode);
> + else
> + return erofs_fscache_acquire_cookie(sb, name, need_inode);
if (EROFS_SB(sb)->opt.domain_id)
return erofs_domain_register_cookie(sb, name, need_inode);
Return erofs_fscache_acquire_cookie(sb, name, need_inode);
Thanks,
Gao Xiang
