From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from userp2120.oracle.com ([156.151.31.85]:43614 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726530AbfFTQuw (ORCPT ); Thu, 20 Jun 2019 12:50:52 -0400 Subject: [PATCH 12/12] xfs_db: add a function to compute btree geometry From: "Darrick J. Wong" Date: Thu, 20 Jun 2019 09:50:46 -0700 Message-ID: <156104944679.1172531.1206025865676357729.stgit@magnolia> In-Reply-To: <156104936953.1172531.2121427277342917243.stgit@magnolia> References: <156104936953.1172531.2121427277342917243.stgit@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: sandeen@sandeen.net, darrick.wong@oracle.com Cc: linux-xfs@vger.kernel.org From: Darrick J. Wong Add a new command to xfs_db that uses a btree type and a record count to report the best and worst case height and level size. This can be used to estimate how overhead a metadata index will add to a filesystem. Signed-off-by: Darrick J. Wong --- db/Makefile | 2 db/btheight.c | 307 ++++++++++++++++++++++++++++++++++++++++++++++ db/command.c | 1 db/command.h | 1 libxfs/libxfs_api_defs.h | 2 5 files changed, 312 insertions(+), 1 deletion(-) create mode 100644 db/btheight.c diff --git a/db/Makefile b/db/Makefile index 8fecfc1c..ceedbebd 100644 --- a/db/Makefile +++ b/db/Makefile @@ -14,7 +14,7 @@ HFILES = addr.h agf.h agfl.h agi.h attr.h attrshort.h bit.h block.h bmap.h \ io.h logformat.h malloc.h metadump.h output.h print.h quit.h sb.h \ sig.h strvec.h text.h type.h write.h attrset.h symlink.h fsmap.h \ fuzz.h -CFILES = $(HFILES:.h=.c) btdump.c info.c +CFILES = $(HFILES:.h=.c) btdump.c btheight.c info.c LSRCFILES = xfs_admin.sh xfs_ncheck.sh xfs_metadump.sh LLDLIBS = $(LIBXFS) $(LIBXLOG) $(LIBFROG) $(LIBUUID) $(LIBRT) $(LIBPTHREAD) diff --git a/db/btheight.c b/db/btheight.c new file mode 100644 index 00000000..df11b347 --- /dev/null +++ b/db/btheight.c @@ -0,0 +1,307 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2019 Oracle. All Rights Reserved. + * Author: Darrick J. Wong + */ +#include "libxfs.h" +#include "command.h" +#include "output.h" +#include "init.h" +#include "io.h" +#include "type.h" +#include "input.h" +#include "../include/convert.h" + +static int refc_maxrecs(struct xfs_mount *mp, int blocklen, int leaf) +{ + return libxfs_refcountbt_maxrecs(blocklen, leaf != 0); +} + +static int rmap_maxrecs(struct xfs_mount *mp, int blocklen, int leaf) +{ + return libxfs_rmapbt_maxrecs(blocklen, leaf); +} + +struct btmap { + const char *tag; + int (*maxrecs)(struct xfs_mount *mp, int blocklen, + int leaf); +} maps[] = { + {"bnobt", libxfs_allocbt_maxrecs}, + {"cntbt", libxfs_allocbt_maxrecs}, + {"inobt", libxfs_inobt_maxrecs}, + {"finobt", libxfs_inobt_maxrecs}, + {"bmapbt", libxfs_bmbt_maxrecs}, + {"refcountbt", refc_maxrecs}, + {"rmapbt", rmap_maxrecs}, +}; + +static void +btheight_help(void) +{ + struct btmap *m; + int i; + + dbprintf(_( +"\n" +" For a given number of btree records and a btree type, report the number of\n" +" records and blocks for each level of the btree, and the total btree size.\n" +" The btree type must be given after the options. A raw btree geometry can\n" +" be provided in the format \"record_bytes:key_bytes:ptr_bytes:header_type\"\n" +" where header_type is one of \"short\", \"long\", \"shortcrc\", or \"longcrc\".\n" +"\n" +" Options:\n" +" -b -- Override the btree block size.\n" +" -n -- Number of records we want to store.\n" +" -w max -- Show only the best case scenario.\n" +" -w min -- Show only the worst case scenario.\n" +"\n" +" Supported btree types:\n" +" " +)); + for (i = 0, m = maps; i < ARRAY_SIZE(maps); i++, m++) + printf("%s ", m->tag); + printf("\n"); +} + +static void +calc_height( + unsigned long long nr_records, + uint *records_per_block) +{ + unsigned int level = 0; + unsigned long long total_blocks = 0; + unsigned long long blocks; + char *levels_suffix = "s"; + char *totblocks_suffix = "s"; + + while (nr_records) { + unsigned int level_rpb = records_per_block[level != 0]; + char *recs_suffix = "s"; + char *blocks_suffix = "s"; + + blocks = (nr_records + level_rpb - 1) / level_rpb; + + if (nr_records == 1) + recs_suffix = ""; + if (blocks == 1) + blocks_suffix = ""; + + printf(_("level %u: %llu record%s, %llu block%s\n"), + level, nr_records, recs_suffix, blocks, + blocks_suffix); + + total_blocks += blocks; + nr_records = blocks == 1 ? 0 : blocks; + level++; + } + + if (level == 1) + levels_suffix = ""; + if (total_blocks == 1) + totblocks_suffix = ""; + + printf(_("%u level%s, %llu block%s total\n"), level, levels_suffix, + total_blocks, totblocks_suffix); +} + +static int +construct_records_per_block( + char *tag, + int blocksize, + unsigned int *records_per_block) +{ + char *toktag; + struct btmap *m; + unsigned int record_size, key_size, ptr_size; + char *p; + int i, ret; + + for (i = 0, m = maps; i < ARRAY_SIZE(maps); i++, m++) { + if (!strcmp(m->tag, tag)) { + records_per_block[0] = m->maxrecs(mp, blocksize, 1); + records_per_block[1] = m->maxrecs(mp, blocksize, 0); + return 0; + } + } + + toktag = strdup(tag); + ret = -1; + + p = strtok(toktag, ":"); + if (!p) { + fprintf(stderr, _("%s: record size not found.\n"), tag); + goto out; + } + record_size = cvt_u16(p, 0); + if (errno) { + perror(p); + goto out; + } + + p = strtok(NULL, ":"); + if (!p) { + fprintf(stderr, _("%s: key size not found.\n"), tag); + goto out; + } + key_size = cvt_u16(p, 0); + if (errno) { + perror(p); + goto out; + } + + p = strtok(NULL, ":"); + if (!p) { + fprintf(stderr, _("%s: pointer size not found.\n"), tag); + goto out; + } + ptr_size = cvt_u16(p, 0); + if (errno) { + perror(p); + goto out; + } + + p = strtok(NULL, ":"); + if (!p) { + fprintf(stderr, _("%s: header type not found.\n"), tag); + goto out; + } + if (!strcmp(p, "short")) + blocksize -= XFS_BTREE_SBLOCK_LEN; + else if (!strcmp(p, "shortcrc")) + blocksize -= XFS_BTREE_SBLOCK_CRC_LEN; + else if (!strcmp(p, "long")) + blocksize -= XFS_BTREE_LBLOCK_LEN; + else if (!strcmp(p, "longcrc")) + blocksize -= XFS_BTREE_LBLOCK_CRC_LEN; + else { + fprintf(stderr, _("%s: unrecognized btree header type."), + p); + goto out; + } + + p = strtok(NULL, ":"); + if (p) { + fprintf(stderr, + _("%s: unrecognized raw btree geometry."), + tag); + goto out; + } + + records_per_block[0] = blocksize / record_size; + records_per_block[1] = blocksize / (key_size + ptr_size); + ret = 0; +out: + free(toktag); + return ret; +} + +#define REPORT_DEFAULT (-1U) +#define REPORT_MAX (1 << 0) +#define REPORT_MIN (1 << 1) + +static void +report( + char *tag, + unsigned int report_what, + unsigned long long nr_records, + unsigned int blocksize) +{ + unsigned int records_per_block[2]; + int ret; + + ret = construct_records_per_block(tag, blocksize, records_per_block); + if (ret) { + printf(_("%s: Unable to determine records per block.\n"), + tag); + return; + } + + if (report_what & REPORT_MAX) { + printf( +_("%s: best case per %u-byte block: %u records (leaf) / %u keyptrs (node)\n"), + tag, blocksize, records_per_block[0], + records_per_block[1]); + + calc_height(nr_records, records_per_block); + } + + if (report_what & REPORT_MIN) { + records_per_block[0] /= 2; + records_per_block[1] /= 2; + + printf( +_("%s: worst case per %u-byte block: %u records (leaf) / %u keyptrs (node)\n"), + tag, blocksize, records_per_block[0], + records_per_block[1]); + + calc_height(nr_records, records_per_block); + } +} + +static int +btheight_f( + int argc, + char **argv) +{ + long long blocksize = mp->m_sb.sb_blocksize; + uint64_t nr_records = 0; + int report_what = REPORT_DEFAULT; + int i, c; + + while ((c = getopt(argc, argv, "b:n:w:")) != -1) { + switch (c) { + case 'b': + errno = 0; + blocksize = cvtnum(mp->m_sb.sb_blocksize, + mp->m_sb.sb_sectsize, + optarg); + if (errno) { + perror(optarg); + return 0; + } + break; + case 'n': + nr_records = cvt_u64(optarg, 0); + if (errno) { + perror(optarg); + return 0; + } + break; + case 'w': + if (!strcmp(optarg, "min")) + report_what = REPORT_MIN; + else if (!strcmp(optarg, "max")) + report_what = REPORT_MAX; + else { + btheight_help(); + return 0; + } + break; + default: + btheight_help(); + return 0; + } + } + + if (argc == optind || blocksize <= 0 || blocksize > INT_MAX || + nr_records == 0) { + btheight_help(); + return 0; + } + + for (i = optind; i < argc; i++) + report(argv[i], report_what, nr_records, blocksize); + + return 0; +} + +static const cmdinfo_t btheight_cmd = + { "btheight", "b", btheight_f, 1, -1, 0, "[-a] [-i]", + N_("compute btree heights"), btheight_help }; + +void +btheight_init(void) +{ + add_command(&btheight_cmd); +} diff --git a/db/command.c b/db/command.c index c7c52342..cb9012c2 100644 --- a/db/command.c +++ b/db/command.c @@ -114,6 +114,7 @@ init_commands(void) block_init(); bmap_init(); btdump_init(); + btheight_init(); check_init(); convert_init(); crc_init(); diff --git a/db/command.h b/db/command.h index eacfd465..d7c5bbd4 100644 --- a/db/command.h +++ b/db/command.h @@ -30,3 +30,4 @@ extern void init_commands(void); extern void btdump_init(void); extern void info_init(void); +extern void btheight_init(void); diff --git a/libxfs/libxfs_api_defs.h b/libxfs/libxfs_api_defs.h index 71a7ef53..fff160ef 100644 --- a/libxfs/libxfs_api_defs.h +++ b/libxfs/libxfs_api_defs.h @@ -124,6 +124,8 @@ #define xfs_dir_ino_validate libxfs_dir_ino_validate #define xfs_initialize_perag_data libxfs_initialize_perag_data #define xfs_inobt_maxrecs libxfs_inobt_maxrecs +#define xfs_rmapbt_maxrecs libxfs_rmapbt_maxrecs +#define xfs_refcountbt_maxrecs libxfs_refcountbt_maxrecs #define xfs_iread_extents libxfs_iread_extents #define xfs_log_calc_minimum_size libxfs_log_calc_minimum_size #define xfs_perag_get libxfs_perag_get