From c6be2bd0a5dd91f98d6b5d2df2c79bc32993352c Mon Sep 17 00:00:00 2001 From: Jeffle Xu Date: Mon, 25 Apr 2022 20:21:33 +0800 Subject: [PATCH] erofs: register fscache volume A new fscache based mode is going to be introduced for erofs, in which case on-demand read semantics is implemented through fscache. As the first step, register fscache volume for each erofs filesystem. That means, data blobs can not be shared among erofs filesystems. In the following iteration, we are going to introduce the domain semantics, in which case several erofs filesystems can belong to one domain, and data blobs can be shared among these erofs filesystems of one domain. Signed-off-by: Jeffle Xu Reviewed-by: Gao Xiang Link: https://lore.kernel.org/r/20220425122143.56815-12-jefflexu@linux.alibaba.com Acked-by: Chao Yu Signed-off-by: Gao Xiang --- fs/erofs/Kconfig | 10 ++++++++++ fs/erofs/Makefile | 1 + fs/erofs/fscache.c | 37 +++++++++++++++++++++++++++++++++++++ fs/erofs/internal.h | 16 ++++++++++++++++ fs/erofs/super.c | 5 +++++ 5 files changed, 69 insertions(+) create mode 100644 fs/erofs/fscache.c diff --git a/fs/erofs/Kconfig b/fs/erofs/Kconfig index f57255ab88ed..85490370e0ca 100644 --- a/fs/erofs/Kconfig +++ b/fs/erofs/Kconfig @@ -98,3 +98,13 @@ config EROFS_FS_ZIP_LZMA systems will be readable without selecting this option. If unsure, say N. + +config EROFS_FS_ONDEMAND + bool "EROFS fscache-based on-demand read support" + depends on CACHEFILES_ONDEMAND && (EROFS_FS=m && FSCACHE || EROFS_FS=y && FSCACHE=y) + default n + help + This permits EROFS to use fscache-backed data blobs with on-demand + read support. + + If unsure, say N. diff --git a/fs/erofs/Makefile b/fs/erofs/Makefile index 8a3317e38e5a..99bbc597a3e9 100644 --- a/fs/erofs/Makefile +++ b/fs/erofs/Makefile @@ -5,3 +5,4 @@ erofs-objs := super.o inode.o data.o namei.o dir.o utils.o pcpubuf.o sysfs.o erofs-$(CONFIG_EROFS_FS_XATTR) += xattr.o erofs-$(CONFIG_EROFS_FS_ZIP) += decompressor.o zmap.o zdata.o erofs-$(CONFIG_EROFS_FS_ZIP_LZMA) += decompressor_lzma.o +erofs-$(CONFIG_EROFS_FS_ONDEMAND) += fscache.o diff --git a/fs/erofs/fscache.c b/fs/erofs/fscache.c new file mode 100644 index 000000000000..7a6d0239ebb1 --- /dev/null +++ b/fs/erofs/fscache.c @@ -0,0 +1,37 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2022, Alibaba Cloud + */ +#include +#include "internal.h" + +int erofs_fscache_register_fs(struct super_block *sb) +{ + struct erofs_sb_info *sbi = EROFS_SB(sb); + struct fscache_volume *volume; + char *name; + int ret = 0; + + 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); + ret = volume ? PTR_ERR(volume) : -EOPNOTSUPP; + volume = NULL; + } + + sbi->volume = volume; + kfree(name); + return ret; +} + +void erofs_fscache_unregister_fs(struct super_block *sb) +{ + struct erofs_sb_info *sbi = EROFS_SB(sb); + + fscache_relinquish_volume(sbi->volume, NULL, false); + sbi->volume = NULL; +} diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h index 52911eaf36f6..71c28aa3f9ce 100644 --- a/fs/erofs/internal.h +++ b/fs/erofs/internal.h @@ -74,6 +74,7 @@ struct erofs_mount_opts { unsigned int max_sync_decompress_pages; #endif unsigned int mount_opt; + char *fsid; }; struct erofs_dev_context { @@ -146,6 +147,9 @@ struct erofs_sb_info { /* sysfs support */ struct kobject s_kobj; /* /sys/fs/erofs/ */ struct completion s_kobj_unregister; + + /* fscache support */ + struct fscache_volume *volume; }; #define EROFS_SB(sb) ((struct erofs_sb_info *)(sb)->s_fs_info) @@ -593,6 +597,18 @@ static inline int z_erofs_load_lzma_config(struct super_block *sb, } #endif /* !CONFIG_EROFS_FS_ZIP */ +/* fscache.c */ +#ifdef CONFIG_EROFS_FS_ONDEMAND +int erofs_fscache_register_fs(struct super_block *sb); +void erofs_fscache_unregister_fs(struct super_block *sb); +#else +static inline int erofs_fscache_register_fs(struct super_block *sb) +{ + return 0; +} +static inline void erofs_fscache_unregister_fs(struct super_block *sb) {} +#endif + #define EFSCORRUPTED EUCLEAN /* Filesystem is corrupted */ #endif /* __EROFS_INTERNAL_H */ diff --git a/fs/erofs/super.c b/fs/erofs/super.c index 46ca7917cb2a..402f919eef6b 100644 --- a/fs/erofs/super.c +++ b/fs/erofs/super.c @@ -641,6 +641,10 @@ static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc) if (erofs_is_fscache_mode(sb)) { sb->s_blocksize = EROFS_BLKSIZ; sb->s_blocksize_bits = LOG_BLOCK_SIZE; + + err = erofs_fscache_register_fs(sb); + if (err) + return err; } else { if (!sb_set_blocksize(sb, EROFS_BLKSIZ)) { erofs_err(sb, "failed to set erofs blksize"); @@ -808,6 +812,7 @@ static void erofs_kill_sb(struct super_block *sb) erofs_free_dev_context(sbi->devs); fs_put_dax(sbi->dax_dev); + erofs_fscache_unregister_fs(sb); kfree(sbi); sb->s_fs_info = NULL; } -- 2.11.0