1 files changed, 57 insertions, 89 deletions

diff --git a/fs/erofs/fscache.c b/fs/erofs/fscache.c
index 014e20962376..96a87c023128 100644
--- a/fs/erofs/fscache.c
+++ b/fs/erofs/fscache.c
@@ -9,6 +9,7 @@
 static DEFINE_MUTEX(erofs_domain_list_lock);
 static DEFINE_MUTEX(erofs_domain_cookies_lock);
 static LIST_HEAD(erofs_domain_list);
+static LIST_HEAD(erofs_domain_cookies_list);
 static struct vfsmount *erofs_pseudo_mnt;
 
 struct erofs_fscache_request {
@@ -164,18 +165,8 @@ static int erofs_fscache_read_folios_async(struct fscache_cookie *cookie,
 static int erofs_fscache_meta_read_folio(struct file *data, struct folio *folio)
 {
 	int ret;
-	struct super_block *sb = folio_mapping(folio)->host->i_sb;
+	struct erofs_fscache *ctx = folio_mapping(folio)->host->i_private;
 	struct erofs_fscache_request *req;
-	struct erofs_map_dev mdev = {
-		.m_deviceid = 0,
-		.m_pa = folio_pos(folio),
-	};
-
-	ret = erofs_map_dev(sb, &mdev);
-	if (ret) {
-		folio_unlock(folio);
-		return ret;
-	}
 
 	req = erofs_fscache_req_alloc(folio_mapping(folio),
 				folio_pos(folio), folio_size(folio));
@@ -184,8 +175,8 @@ static int erofs_fscache_meta_read_folio(struct file *data, struct folio *folio)
 		return PTR_ERR(req);
 	}
 
-	ret = erofs_fscache_read_folios_async(mdev.m_fscache->cookie,
-				req, mdev.m_pa, folio_size(folio));
+	ret = erofs_fscache_read_folios_async(ctx->cookie, req,
+				folio_pos(folio), folio_size(folio));
 	if (ret)
 		req->error = ret;
 
@@ -207,7 +198,7 @@ static int erofs_fscache_data_read_slice(struct erofs_fscache_request *primary)
 	int ret;
 
 	map.m_la = pos;
-	ret = erofs_map_blocks(inode, &map, EROFS_GET_BLOCKS_RAW);
+	ret = erofs_map_blocks(inode, &map);
 	if (ret)
 		return ret;
 
@@ -328,8 +319,6 @@ const struct address_space_operations erofs_fscache_access_aops = {
 
 static void erofs_fscache_domain_put(struct erofs_domain *domain)
 {
-	if (!domain)
-		return;
 	mutex_lock(&erofs_domain_list_lock);
 	if (refcount_dec_and_test(&domain->ref)) {
 		list_del(&domain->list);
@@ -337,8 +326,8 @@ static void erofs_fscache_domain_put(struct erofs_domain *domain)
 			kern_unmount(erofs_pseudo_mnt);
 			erofs_pseudo_mnt = NULL;
 		}
-		mutex_unlock(&erofs_domain_list_lock);
 		fscache_relinquish_volume(domain->volume, NULL, false);
+		mutex_unlock(&erofs_domain_list_lock);
 		kfree(domain->domain_id);
 		kfree(domain);
 		return;
@@ -431,19 +420,21 @@ static int erofs_fscache_register_domain(struct super_block *sb)
 	return err;
 }
 
-static
-struct erofs_fscache *erofs_fscache_acquire_cookie(struct super_block *sb,
-						   char *name,
-						   unsigned int flags)
+static struct erofs_fscache *erofs_fscache_acquire_cookie(struct super_block *sb,
+						char *name, unsigned int flags)
 {
 	struct fscache_volume *volume = EROFS_SB(sb)->volume;
 	struct erofs_fscache *ctx;
 	struct fscache_cookie *cookie;
+	struct super_block *isb;
+	struct inode *inode;
 	int ret;
 
 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
 	if (!ctx)
 		return ERR_PTR(-ENOMEM);
+	INIT_LIST_HEAD(&ctx->node);
+	refcount_set(&ctx->ref, 1);
 
 	cookie = fscache_acquire_cookie(volume, FSCACHE_ADV_WANT_CACHE_SIZE,
 					name, strlen(name), NULL, 0, 0);
@@ -452,32 +443,32 @@ struct erofs_fscache *erofs_fscache_acquire_cookie(struct super_block *sb,
 		ret = -EINVAL;
 		goto err;
 	}
-
 	fscache_use_cookie(cookie, false);
-	ctx->cookie = cookie;
-
-	if (flags & EROFS_REG_COOKIE_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;
+	/*
+	 * Allocate anonymous inode in global pseudo mount for shareable blobs,
+	 * so that they are accessible among erofs fs instances.
+	 */
+	isb = flags & EROFS_REG_COOKIE_SHARE ? erofs_pseudo_mnt->mnt_sb : sb;
+	inode = new_inode(isb);
+	if (!inode) {
+		erofs_err(sb, "failed to get anon inode for %s", name);
+		ret = -ENOMEM;
+		goto err_cookie;
 	}
 
+	inode->i_size = OFFSET_MAX;
+	inode->i_mapping->a_ops = &erofs_fscache_meta_aops;
+	mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS);
+	inode->i_private = ctx;
+
+	ctx->cookie = cookie;
+	ctx->inode = inode;
 	return ctx;
 
 err_cookie:
-	fscache_unuse_cookie(ctx->cookie, NULL, NULL);
-	fscache_relinquish_cookie(ctx->cookie, false);
+	fscache_unuse_cookie(cookie, NULL, NULL);
+	fscache_relinquish_cookie(cookie, false);
 err:
 	kfree(ctx);
 	return ERR_PTR(ret);
@@ -492,13 +483,9 @@ static void erofs_fscache_relinquish_cookie(struct erofs_fscache *ctx)
 	kfree(ctx);
 }
 
-static
-struct erofs_fscache *erofs_fscache_domain_init_cookie(struct super_block *sb,
-						       char *name,
-						       unsigned int flags)
+static struct erofs_fscache *erofs_domain_init_cookie(struct super_block *sb,
+						char *name, unsigned int flags)
 {
-	int err;
-	struct inode *inode;
 	struct erofs_fscache *ctx;
 	struct erofs_domain *domain = EROFS_SB(sb)->domain;
 
@@ -508,55 +495,38 @@ struct erofs_fscache *erofs_fscache_domain_init_cookie(struct super_block *sb,
 
 	ctx->name = kstrdup(name, GFP_KERNEL);
 	if (!ctx->name) {
-		err = -ENOMEM;
-		goto out;
-	}
-
-	inode = new_inode(erofs_pseudo_mnt->mnt_sb);
-	if (!inode) {
-		err = -ENOMEM;
-		goto out;
+		erofs_fscache_relinquish_cookie(ctx);
+		return ERR_PTR(-ENOMEM);
 	}
 
-	ctx->domain = domain;
-	ctx->anon_inode = inode;
-	inode->i_private = ctx;
 	refcount_inc(&domain->ref);
+	ctx->domain = domain;
+	list_add(&ctx->node, &erofs_domain_cookies_list);
 	return ctx;
-out:
-	erofs_fscache_relinquish_cookie(ctx);
-	return ERR_PTR(err);
 }
 
-static
-struct erofs_fscache *erofs_domain_register_cookie(struct super_block *sb,
-						   char *name,
-						   unsigned int flags)
+static struct erofs_fscache *erofs_domain_register_cookie(struct super_block *sb,
+						char *name, unsigned int flags)
 {
-	struct inode *inode;
 	struct erofs_fscache *ctx;
 	struct erofs_domain *domain = EROFS_SB(sb)->domain;
-	struct super_block *psb = erofs_pseudo_mnt->mnt_sb;
 
+	flags |= EROFS_REG_COOKIE_SHARE;
 	mutex_lock(&erofs_domain_cookies_lock);
-	spin_lock(&psb->s_inode_list_lock);
-	list_for_each_entry(inode, &psb->s_inodes, i_sb_list) {
-		ctx = inode->i_private;
-		if (!ctx || ctx->domain != domain || strcmp(ctx->name, name))
+	list_for_each_entry(ctx, &erofs_domain_cookies_list, node) {
+		if (ctx->domain != domain || strcmp(ctx->name, name))
 			continue;
 		if (!(flags & EROFS_REG_COOKIE_NEED_NOEXIST)) {
-			igrab(inode);
+			refcount_inc(&ctx->ref);
 		} else {
 			erofs_err(sb, "%s already exists in domain %s", name,
 				  domain->domain_id);
 			ctx = ERR_PTR(-EEXIST);
 		}
-		spin_unlock(&psb->s_inode_list_lock);
 		mutex_unlock(&erofs_domain_cookies_lock);
 		return ctx;
 	}
-	spin_unlock(&psb->s_inode_list_lock);
-	ctx = erofs_fscache_domain_init_cookie(sb, name, flags);
+	ctx = erofs_domain_init_cookie(sb, name, flags);
 	mutex_unlock(&erofs_domain_cookies_lock);
 	return ctx;
 }
@@ -572,23 +542,22 @@ struct erofs_fscache *erofs_fscache_register_cookie(struct super_block *sb,
 
 void erofs_fscache_unregister_cookie(struct erofs_fscache *ctx)
 {
-	bool drop;
-	struct erofs_domain *domain;
+	struct erofs_domain *domain = NULL;
 
 	if (!ctx)
 		return;
-	domain = ctx->domain;
-	if (domain) {
-		mutex_lock(&erofs_domain_cookies_lock);
-		drop = atomic_read(&ctx->anon_inode->i_count) == 1;
-		iput(ctx->anon_inode);
-		mutex_unlock(&erofs_domain_cookies_lock);
-		if (!drop)
-			return;
-	}
+	if (!ctx->domain)
+		return erofs_fscache_relinquish_cookie(ctx);
 
-	erofs_fscache_relinquish_cookie(ctx);
-	erofs_fscache_domain_put(domain);
+	mutex_lock(&erofs_domain_cookies_lock);
+	if (refcount_dec_and_test(&ctx->ref)) {
+		domain = ctx->domain;
+		list_del(&ctx->node);
+		erofs_fscache_relinquish_cookie(ctx);
+	}
+	mutex_unlock(&erofs_domain_cookies_lock);
+	if (domain)
+		erofs_fscache_domain_put(domain);
 }
 
 int erofs_fscache_register_fs(struct super_block *sb)
@@ -596,7 +565,7 @@ int erofs_fscache_register_fs(struct super_block *sb)
 	int ret;
 	struct erofs_sb_info *sbi = EROFS_SB(sb);
 	struct erofs_fscache *fscache;
-	unsigned int flags;
+	unsigned int flags = 0;
 
 	if (sbi->domain_id)
 		ret = erofs_fscache_register_domain(sb);
@@ -615,7 +584,6 @@ int erofs_fscache_register_fs(struct super_block *sb)
 	 *
 	 * Acquired domain/volume will be relinquished in kill_sb() on error.
 	 */
-	flags = EROFS_REG_COOKIE_NEED_INODE;
 	if (sbi->domain_id)
 		flags |= EROFS_REG_COOKIE_NEED_NOEXIST;
 	fscache = erofs_fscache_register_cookie(sb, sbi->fsid, flags);