diff options
author | Jia Zhu <zhujia.zj@bytedance.com> | 2022-09-18 12:34:53 +0800 |
---|---|---|
committer | Gao Xiang <hsiangkao@linux.alibaba.com> | 2022-09-20 08:01:53 +0800 |
commit | 8b7adf1dff3d5baf687acda936f193f80b7e0179 (patch) | |
tree | fd151153106005976743f20a8d8b71d1c0d4ec68 /fs/erofs/fscache.c | |
parent | e1de2da0b7ac2dc0120c2ba8c7044788611933ea (diff) | |
download | linux-8b7adf1dff3d5baf687acda936f193f80b7e0179.tar.bz2 |
erofs: introduce fscache-based domain
A new fscache-based shared domain mode is going to be introduced for
erofs. In which case, same data blobs in same domain will be shared
and reused to reduce on-disk space usage.
The implementation of sharing blobs will be introduced in subsequent
patches.
Signed-off-by: Jia Zhu <zhujia.zj@bytedance.com>
Reviewed-by: Jingbo Xu <jefflexu@linux.alibaba.com>
Link: https://lore.kernel.org/r/20220918043456.147-4-zhujia.zj@bytedance.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Diffstat (limited to 'fs/erofs/fscache.c')
-rw-r--r-- | fs/erofs/fscache.c | 129 |
1 files changed, 112 insertions, 17 deletions
diff --git a/fs/erofs/fscache.c b/fs/erofs/fscache.c index 1eb63987e815..8a1be6077ca4 100644 --- a/fs/erofs/fscache.c +++ b/fs/erofs/fscache.c @@ -1,10 +1,14 @@ // SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright (C) 2022, Alibaba Cloud + * Copyright (C) 2022, Bytedance Inc. All rights reserved. */ #include <linux/fscache.h> #include "internal.h" +static DEFINE_MUTEX(erofs_domain_list_lock); +static LIST_HEAD(erofs_domain_list); + static struct netfs_io_request *erofs_fscache_alloc_request(struct address_space *mapping, loff_t start, size_t len) { @@ -421,6 +425,99 @@ const struct address_space_operations erofs_fscache_access_aops = { .readahead = erofs_fscache_readahead, }; +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); + mutex_unlock(&erofs_domain_list_lock); + fscache_relinquish_volume(domain->volume, NULL, false); + kfree(domain->domain_id); + kfree(domain); + return; + } + mutex_unlock(&erofs_domain_list_lock); +} + +static int erofs_fscache_register_volume(struct super_block *sb) +{ + struct erofs_sb_info *sbi = EROFS_SB(sb); + char *domain_id = sbi->opt.domain_id; + struct fscache_volume *volume; + char *name; + int ret = 0; + + name = kasprintf(GFP_KERNEL, "erofs,%s", + domain_id ? domain_id : sbi->opt.fsid); + if (!name) + return -ENOMEM; + + volume = fscache_acquire_volume(name, NULL, NULL, 0); + if (IS_ERR_OR_NULL(volume)) { + erofs_err(sb, "failed to register volume for %s", name); + ret = volume ? PTR_ERR(volume) : -EOPNOTSUPP; + volume = NULL; + } + + sbi->volume = volume; + kfree(name); + return ret; +} + +static int erofs_fscache_init_domain(struct super_block *sb) +{ + int err; + struct erofs_domain *domain; + struct erofs_sb_info *sbi = EROFS_SB(sb); + + domain = kzalloc(sizeof(struct erofs_domain), GFP_KERNEL); + if (!domain) + return -ENOMEM; + + domain->domain_id = kstrdup(sbi->opt.domain_id, GFP_KERNEL); + if (!domain->domain_id) { + kfree(domain); + return -ENOMEM; + } + + err = erofs_fscache_register_volume(sb); + if (err) + goto out; + + domain->volume = sbi->volume; + refcount_set(&domain->ref, 1); + list_add(&domain->list, &erofs_domain_list); + sbi->domain = domain; + return 0; +out: + kfree(domain->domain_id); + kfree(domain); + return err; +} + +static int erofs_fscache_register_domain(struct super_block *sb) +{ + int err; + struct erofs_domain *domain; + struct erofs_sb_info *sbi = EROFS_SB(sb); + + mutex_lock(&erofs_domain_list_lock); + list_for_each_entry(domain, &erofs_domain_list, list) { + if (!strcmp(domain->domain_id, sbi->opt.domain_id)) { + sbi->domain = domain; + sbi->volume = domain->volume; + refcount_inc(&domain->ref); + mutex_unlock(&erofs_domain_list_lock); + return 0; + } + } + err = erofs_fscache_init_domain(sb); + mutex_unlock(&erofs_domain_list_lock); + return err; +} + struct erofs_fscache *erofs_fscache_register_cookie(struct super_block *sb, char *name, bool need_inode) { @@ -484,27 +581,19 @@ void erofs_fscache_unregister_cookie(struct erofs_fscache *ctx) int erofs_fscache_register_fs(struct super_block *sb) { + int ret; struct erofs_sb_info *sbi = EROFS_SB(sb); - struct fscache_volume *volume; struct erofs_fscache *fscache; - char *name; - - name = kasprintf(GFP_KERNEL, "erofs,%s", sbi->opt.fsid); - if (!name) - return -ENOMEM; - volume = fscache_acquire_volume(name, NULL, NULL, 0); - if (IS_ERR_OR_NULL(volume)) { - erofs_err(sb, "failed to register volume for %s", name); - kfree(name); - return volume ? PTR_ERR(volume) : -EOPNOTSUPP; - } - - sbi->volume = volume; - kfree(name); + if (sbi->opt.domain_id) + ret = erofs_fscache_register_domain(sb); + else + ret = erofs_fscache_register_volume(sb); + if (ret) + return ret; + /* acquired domain/volume will be relinquished in kill_sb() on error */ fscache = erofs_fscache_register_cookie(sb, sbi->opt.fsid, true); - /* acquired volume will be relinquished in kill_sb() */ if (IS_ERR(fscache)) return PTR_ERR(fscache); @@ -517,7 +606,13 @@ void erofs_fscache_unregister_fs(struct super_block *sb) struct erofs_sb_info *sbi = EROFS_SB(sb); erofs_fscache_unregister_cookie(sbi->s_fscache); - fscache_relinquish_volume(sbi->volume, NULL, false); + + if (sbi->domain) + erofs_fscache_domain_put(sbi->domain); + else + fscache_relinquish_volume(sbi->volume, NULL, false); + sbi->s_fscache = NULL; sbi->volume = NULL; + sbi->domain = NULL; } |