Commit a9849560 authored by Jia Zhu's avatar Jia Zhu Committed by Gao Xiang
Browse files

erofs: introduce a pseudo mnt to manage shared cookies 



Use a pseudo mnt to manage shared cookies.

Signed-off-by: default avatarJia Zhu <zhujia.zj@bytedance.com>
Reviewed-by: default avatarJingbo Xu <jefflexu@linux.alibaba.com>
Link: https://lore.kernel.org/r/20220918043456.147-5-zhujia.zj@bytedance.com


Signed-off-by: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
parent 8b7adf1d

fs/erofs/fscache.c

+13 −0
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 


static DEFINE_MUTEX(erofs_domain_list_lock);

static LIST_HEAD(erofs_domain_list);

static struct vfsmount *erofs_pseudo_mnt;



static struct netfs_io_request *erofs_fscache_alloc_request(struct address_space *mapping,

					     loff_t start, size_t len)
@@ -432,6 +433,10 @@ static void erofs_fscache_domain_put(struct erofs_domain *domain) 
	mutex_lock(&erofs_domain_list_lock);

	if (refcount_dec_and_test(&domain->ref)) {

		list_del(&domain->list);

		if (list_empty(&erofs_domain_list)) {

			kern_unmount(erofs_pseudo_mnt);

			erofs_pseudo_mnt = NULL;

		}

		mutex_unlock(&erofs_domain_list_lock);

		fscache_relinquish_volume(domain->volume, NULL, false);

		kfree(domain->domain_id);
@@ -486,6 +491,14 @@ static int erofs_fscache_init_domain(struct super_block *sb) 
	if (err)

		goto out;



	if (!erofs_pseudo_mnt) {

		erofs_pseudo_mnt = kern_mount(&erofs_fs_type);

		if (IS_ERR(erofs_pseudo_mnt)) {

			err = PTR_ERR(erofs_pseudo_mnt);

			goto out;

		}

	}



	domain->volume = sbi->volume;

	refcount_set(&domain->ref, 1);

	list_add(&domain->list, &erofs_domain_list);

fs/erofs/internal.h

+1 −0
Original line number Diff line number Diff line
@@ -373,6 +373,7 @@ struct page *erofs_grab_cache_page_nowait(struct address_space *mapping, 
}



extern const struct super_operations erofs_sops;

extern struct file_system_type erofs_fs_type;



extern const struct address_space_operations erofs_raw_access_aops;

extern const struct address_space_operations z_erofs_aops;

fs/erofs/super.c

+31 −2
Original line number Diff line number Diff line
@@ -676,6 +676,13 @@ static const struct export_operations erofs_export_ops = { 
	.get_parent = erofs_get_parent,

};



static int erofs_fc_fill_pseudo_super(struct super_block *sb, struct fs_context *fc)

{

	static const struct tree_descr empty_descr = {""};



	return simple_fill_super(sb, EROFS_SUPER_MAGIC, &empty_descr);

}



static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc)

{

	struct inode *inode;
@@ -776,6 +783,11 @@ static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc) 
	return 0;

}



static int erofs_fc_anon_get_tree(struct fs_context *fc)

{

	return get_tree_nodev(fc, erofs_fc_fill_pseudo_super);

}



static int erofs_fc_get_tree(struct fs_context *fc)

{

	struct erofs_fs_context *ctx = fc->fs_private;
@@ -844,10 +856,21 @@ static const struct fs_context_operations erofs_context_ops = { 
	.free		= erofs_fc_free,

};



static const struct fs_context_operations erofs_anon_context_ops = {

	.get_tree       = erofs_fc_anon_get_tree,

};



static int erofs_init_fs_context(struct fs_context *fc)

{

	struct erofs_fs_context *ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);

	struct erofs_fs_context *ctx;



	/* pseudo mount for anon inodes */

	if (fc->sb_flags & SB_KERNMOUNT) {

		fc->ops = &erofs_anon_context_ops;

		return 0;

	}



	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);

	if (!ctx)

		return -ENOMEM;

	ctx->devs = kzalloc(sizeof(struct erofs_dev_context), GFP_KERNEL);
@@ -874,6 +897,12 @@ static void erofs_kill_sb(struct super_block *sb) 


	WARN_ON(sb->s_magic != EROFS_SUPER_MAGIC);



	/* pseudo mount for anon inodes */

	if (sb->s_flags & SB_KERNMOUNT) {

		kill_anon_super(sb);

		return;

	}



	if (erofs_is_fscache_mode(sb))

		kill_anon_super(sb);

	else
@@ -907,7 +936,7 @@ static void erofs_put_super(struct super_block *sb) 
	erofs_fscache_unregister_fs(sb);

}



static struct file_system_type erofs_fs_type = {

struct file_system_type erofs_fs_type = {

	.owner          = THIS_MODULE,

	.name           = "erofs",

	.init_fs_context = erofs_init_fs_context,