From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cn.fujitsu.com ([59.151.112.132]:52918 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1753256AbbL2ICP (ORCPT ); Tue, 29 Dec 2015 03:02:15 -0500 Received: from G08CNEXCHPEKD02.g08.fujitsu.local (unknown [10.167.33.83]) by cn.fujitsu.com (Postfix) with ESMTP id 0F2834092579 for ; Tue, 29 Dec 2015 16:01:12 +0800 (CST) From: Qu Wenruo To: Subject: [PATCH 2/7] btrfs-progs: dedup: Add enable command for dedup command group Date: Tue, 29 Dec 2015 16:01:04 +0800 Message-ID: <1451376069-30414-3-git-send-email-quwenruo@cn.fujitsu.com> In-Reply-To: <1451376069-30414-1-git-send-email-quwenruo@cn.fujitsu.com> References: <1451376069-30414-1-git-send-email-quwenruo@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-btrfs-owner@vger.kernel.org List-ID: Add enable subcommand for dedup commmand group. Signed-off-by: Qu Wenruo --- Documentation/btrfs-dedup.asciidoc | 62 ++++++++++++++++++- cmds-dedup.c | 120 +++++++++++++++++++++++++++++++++++++ ioctl.h | 2 + kerncompat.h | 5 ++ 4 files changed, 188 insertions(+), 1 deletion(-) diff --git a/Documentation/btrfs-dedup.asciidoc b/Documentation/btrfs-dedup.asciidoc index 354313f..652f22d 100644 --- a/Documentation/btrfs-dedup.asciidoc +++ b/Documentation/btrfs-dedup.asciidoc @@ -19,7 +19,67 @@ use with caution. SUBCOMMAND ---------- -Nothing yet +*enable* [options] :: +Enable in-band de-duplication for a filesystem. ++ +`Options` ++ +-s|--storage-backend :::: +Specify de-duplication hash storage backend. +Supported backends are 'ondisk' and 'inmemory' +If not specified, default value is 'inmemory'. ++ +Refer to *BACKENDS* sector for more information. + +-b|--blocksize :::: +Specify dedup block size. +Supported values are power of 2 from '16K' to '128K'. +Default value is the larger of page size and '32K'. ++ +Refer to *BLOCKSIZE* sector for more information. + +-a|--hash-algorithm :::: +Specify hash algorithm. +Only 'sha256' is supported yet. + +-l|--limit :::: +Specify limit of hash number. +Only works for 'inmemory' backend. +If *LIMIT* is zero, there will be no limit at all. Use with caution as it can +use up all the memory for dedup hash. +Default value is 4096 if using 'inmemory' backend. + +BACKENDS +-------- +Btrfs in-band de-duplication support two different backends with their own +features. + +In-memory backend:: +Designed for speed, in-memory backend will keep all dedup hash into memory. +And it has a limit of number of hash kept in-memory. +Hashes over the limit will be dropped following last recent use behavior. +So this backend has a consistent overhead for given limit but can't ensure +any all duplicated data will be de-duplicated. ++ +After umount and mount, in-memory backend need to refill its hash table. + +On-disk backend:: +Designed for de-duplication rate, on-disk backend will keep dedup hash on disk. +This behavior may cause extra disk IO for de-duplication, but will have a much +higher dedup rate. ++ +After umount and mount, on-disk backend still has its hash on disk, no need to +refill its dedup hash table. + +BLOCKSIZE +--------- +Block in-band de-duplication is done at block size unit. +Any data smaller than dedup block size won't go through the dedup backends. + +Smaller block size will cause more fragments and lower performance, but a +higher dedup rate. +Larger block size will cause less fragments and higher performance, but a +lower dedup rate. EXIT STATUS ----------- diff --git a/cmds-dedup.c b/cmds-dedup.c index 800df34..e116f4c 100644 --- a/cmds-dedup.c +++ b/cmds-dedup.c @@ -36,8 +36,128 @@ static const char * const dedup_cmd_group_usage[] = { static const char dedup_cmd_group_info[] = "manage inband(write time) de-duplication"; +static const char * const cmd_dedup_enable_usage[] = { + "btrfs dedup enable [options] ", + "Enable in-band(write time) de-duplication of a btrfs.", + "", + "-s|--storage-backend ", + " specify dedup hash storage backend", + " supported backend: 'ondisk', 'inmemory'", + " inmemory is the default backend", + "-b|--blocksize ", + " specify dedup block size", + " default value is the larger of page size and 16K", + "-a|--hash-algorithm ", + " specify hash algorithm", + " only 'sha256' is supported yet", + "-l|--limit ", + " specify limit of hash number", + " only for 'inmemory' backend", + " default value is 4096 if using 'inmemory' backend", + NULL +}; + +static int cmd_dedup_enable(int argc, char **argv) +{ + int ret; + int fd; + char *path; + int pagesize = sysconf(_SC_PAGESIZE); + u64 blocksize = max(pagesize, BTRFS_DEDUP_BLOCKSIZE_DEFAULT); + u16 hash_type = BTRFS_DEDUP_HASH_SHA256; + u16 backend = BTRFS_DEDUP_BACKEND_INMEMORY; + u64 limit = 0; + struct btrfs_ioctl_dedup_args dargs; + DIR *dirstream; + + while (1) { + int c; + static const struct option long_options[] = { + { "storage-backend", required_argument, NULL, 's'}, + { "blocksize", required_argument, NULL, 'b'}, + { "hash-algorithm", required_argument, NULL, 'a'}, + { "limit", required_argument, NULL, 'l'}, + { NULL, 0, NULL, 0} + }; + + c = getopt_long(argc, argv, "s:b:a:l:", long_options, NULL); + if (c < 0) + break; + switch (c) { + case 's': + if (!strcmp("ondisk", optarg)) + backend = BTRFS_DEDUP_BACKEND_ONDISK; + else if (!strcmp("inmemory", optarg)) + backend = BTRFS_DEDUP_BACKEND_INMEMORY; + else { + error("unsupported dedup backend: %s", optarg); + exit(1); + } + break; + case 'b': + blocksize = parse_size(optarg); + break; + case 'a': + if (strcmp("sha256", optarg)) { + error("unsupported dedup hash algorithm: %s", + optarg); + return 1; + } + break; + case 'l': + limit = parse_size(optarg); + break; + } + } + + path = argv[optind]; + if (check_argc_exact(argc - optind, 1)) + usage(cmd_dedup_enable_usage); + + /* Validation check */ + if (!is_power_of_2(blocksize) || + blocksize > BTRFS_DEDUP_BLOCKSIZE_MAX || + blocksize < BTRFS_DEDUP_BLOCKSIZE_MIN || + blocksize < pagesize) { + error("invalid dedup blocksize: %llu, not in range [%llu,%llu] nor power of 2", + blocksize, max(pagesize, BTRFS_DEDUP_BLOCKSIZE_MIN), + BTRFS_DEDUP_BLOCKSIZE_MAX); + return 1; + } + if (limit && backend == BTRFS_DEDUP_BACKEND_ONDISK) { + error("limit is only valid for 'inmemory' backend"); + return 1; + } + + fd = open_file_or_dir(path, &dirstream); + if (fd < 0) { + error("failed to open file or directory: %s", path); + return 1; + } + memset(&dargs, 0, sizeof(dargs)); + dargs.cmd = BTRFS_DEDUP_CTL_ENABLE; + dargs.blocksize = blocksize; + dargs.hash_type = hash_type; + dargs.limit_nr = limit; + dargs.backend = backend; + + ret = ioctl(fd, BTRFS_IOC_DEDUP_CTL, &dargs); + if (ret < 0) { + error("failed to enable inband deduplication: %s", + strerror(errno)); + ret = 1; + goto out; + } + ret = 0; + +out: + close_file_or_dir(fd, dirstream); + return ret; +} + const struct cmd_group dedup_cmd_group = { dedup_cmd_group_usage, dedup_cmd_group_info, { + { "enable", cmd_dedup_enable, cmd_dedup_enable_usage, NULL, 0}, NULL_CMD_STRUCT } }; diff --git a/ioctl.h b/ioctl.h index 7c9221d..6bff671 100644 --- a/ioctl.h +++ b/ioctl.h @@ -698,6 +698,8 @@ static inline char *btrfs_err_str(enum btrfs_err_code err_code) struct btrfs_ioctl_dev_replace_args) #define BTRFS_IOC_FILE_EXTENT_SAME _IOWR(BTRFS_IOCTL_MAGIC, 54, \ struct btrfs_ioctl_same_args) +#define BTRFS_IOC_DEDUP_CTL _IOWR(BTRFS_IOCTL_MAGIC, 55, \ + struct btrfs_ioctl_dedup_args) #define BTRFS_IOC_GET_FEATURES _IOR(BTRFS_IOCTL_MAGIC, 57, \ struct btrfs_ioctl_feature_flags) #define BTRFS_IOC_SET_FEATURES _IOW(BTRFS_IOCTL_MAGIC, 57, \ diff --git a/kerncompat.h b/kerncompat.h index 7c627ba..db1d77b 100644 --- a/kerncompat.h +++ b/kerncompat.h @@ -310,6 +310,11 @@ static inline long IS_ERR(const void *ptr) #define __bitwise #endif +static inline int is_power_of_2(unsigned long n) +{ + return (n != 0 && ((n & (n - 1)) == 0)); +} + typedef u16 __bitwise __le16; typedef u16 __bitwise __be16; typedef u32 __bitwise __le32; -- 2.6.4