From: Theodore Tso Subject: Re: [PATCH] e2fsprogs: New bitmap and inode table allocation for FLEX_BG v2 Date: Tue, 25 Mar 2008 18:24:27 -0400 Message-ID: <20080325222426.GA24980@mit.edu> References: <20080213204750.5666a560@gara> <20080324134650.GA13621@mit.edu> <20080325171202.1dce62a6@gara> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-ext4 To: "Jose R. Santos" Return-path: Received: from BISCAYNE-ONE-STATION.MIT.EDU ([18.7.7.80]:52023 "EHLO biscayne-one-station.mit.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753449AbYCYWYc (ORCPT ); Tue, 25 Mar 2008 18:24:32 -0400 Content-Disposition: inline In-Reply-To: <20080325171202.1dce62a6@gara> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Tue, Mar 25, 2008 at 05:12:02PM -0500, Jose R. Santos wrote: > As I started looking at implementing this, I noticed that patch in pu > has some chunks that don't belong to the flex_bg patch. These are the > offending lines at the end on the commit: > > + if (!force && fs_param.s_blocks_count >= ((unsigned) 1 << 31)) { > + com_err(program_name, 0, > + _("Filesystem too large. No more than 2**31-1 blocks\n" > + "\t (8TB using a blocksize of 4k) are currently supported.")); > + exit(1); > + } > + > + if ((blocksize > 4096) && > + (fs_param.s_feature_compat & EXT3_FEATURE_COMPAT_HAS_JOURNAL)) > + fprintf(stderr, _("\nWarning: some 2.4 kernels do not support " > + "blocksizes greater than 4096\n\tusing ext3. " > + "Use -b 4096 if this is an issue for you.\n\n")); > + > > These line probably got damaged during one of the merges. You probably > want to fix this so that the changes are not lost when rebasing to a > newer flex_bg patch. Actually, these were supposed to be deleted, and yes, a badly done merge put them back in. :-) So just yank them from your version; I already did in mine, before I decided there was enough other stuff that needed to be changed that I'd let you resend the patch. - Ted This is what I had before I decided to stop. This just had the rename of the functions to remove ext2fs_, making the functions static, and removing the mis-merged lines. commit 73bcad3ba9350ce0fd40fd3f89ccc2ef1143a8da Author: Jose R. Santos Date: Wed Feb 13 20:47:50 2008 -0600 mke2fs: New bitmap and inode table allocation for FLEX_BG Change the way we allocate bitmaps and inode tables if the FLEX_BG feature is used at mke2fs time. It places calculates a new offset for bitmaps and inode table base on the number of groups that the user wishes to pack together using the new "-G" option. Creating a filesystem with 64 block groups in a flex group can be done by: mke2fs -j -I 256 -O flex_bg -G 32 /dev/sdX Signed-off-by: Jose R. Santos Signed-off-by: Valerie Clement Signed-off-by: Theodore Ts'o diff --git a/lib/ext2fs/alloc_tables.c b/lib/ext2fs/alloc_tables.c index 9b4f0e5..2183198 100644 --- a/lib/ext2fs/alloc_tables.c +++ b/lib/ext2fs/alloc_tables.c @@ -27,18 +27,88 @@ #include "ext2_fs.h" #include "ext2fs.h" +static void bgd_set_flex_meta_flag(ext2_filsys fs, blk_t block) +{ + dgrp_t group; + + group = ext2fs_group_of_blk(fs, block); + if (!(fs->group_desc[group].bg_flags & EXT2_BG_FLEX_METADATA)) + fs->group_desc[group].bg_flags |= EXT2_BG_FLEX_METADATA; +} + +/* + * This routine searches for free blocks that can allocate a full + * group of bitmaps or inode tables for a flexbg group. Returns the + * block number with a correct offset were the bitmaps and inode + * tables can be allocated continously and in order. + */ +static blk_t flexbg_offset(ext2_filsys fs, dgrp_t group, blk_t start_blk, + ext2fs_block_bitmap bmap, int offset, int size) +{ + int flexbg, flexbg_size, elem_size; + blk_t last_blk, first_free = 0; + dgrp_t last_grp; + + flexbg_size = 1 << fs->super->s_log_groups_per_flex; + flexbg = group / flexbg_size; + + if (size > fs->super->s_blocks_per_group / 8) + size = fs->super->s_blocks_per_group / 8; + + /* + * Dont do a long search if the previous block + * search is still valid. + */ + if (start_blk && group % flexbg_size) { + if (size > flexbg_size) + elem_size = fs->inode_blocks_per_group; + else + elem_size = 1; + if (ext2fs_test_block_bitmap_range(bmap, start_blk + elem_size, + size)) + return start_blk + elem_size; + } + + start_blk = ext2fs_group_first_block(fs, flexbg_size * flexbg); + last_grp = group | (flexbg_size - 1); + if (last_grp > fs->group_desc_count) + last_grp = fs->group_desc_count; + last_blk = ext2fs_group_last_block(fs, last_grp); + + /* Find the first available block */ + if (ext2fs_get_free_blocks(fs, start_blk, last_blk, 1, bmap, + &first_free)) + return first_free; + + if (ext2fs_get_free_blocks(fs, first_free + offset, last_blk, size, + bmap, &first_free)) + return first_free; + + return first_free; +} + errcode_t ext2fs_allocate_group_table(ext2_filsys fs, dgrp_t group, ext2fs_block_bitmap bmap) { errcode_t retval; blk_t group_blk, start_blk, last_blk, new_blk, blk; - int j; + dgrp_t last_grp; + int j, rem_grps, flexbg_size = 0; group_blk = ext2fs_group_first_block(fs, group); last_blk = ext2fs_group_last_block(fs, group); if (!bmap) bmap = fs->block_map; + + if (EXT2_HAS_INCOMPAT_FEATURE(fs->super, + EXT4_FEATURE_INCOMPAT_FLEX_BG)) { + flexbg_size = 1 << fs->super->s_log_groups_per_flex; + last_grp = group | (flexbg_size - 1); + rem_grps = last_grp - group; + if (last_grp > fs->group_desc_count) + last_grp = fs->group_desc_count; + } /* * Allocate the block and inode bitmaps, if necessary @@ -56,6 +126,14 @@ errcode_t ext2fs_allocate_group_table(ext2_filsys fs, dgrp_t group, } else start_blk = group_blk; + if (flexbg_size) { + int prev_block = 0; + if (group && fs->group_desc[group-1].bg_block_bitmap) + prev_block = fs->group_desc[group-1].bg_block_bitmap; + start_blk = flexbg_offset(fs, group, prev_block, bmap, 0, rem_grps); + last_blk = ext2fs_group_last_block(fs, last_grp); + } + if (!fs->group_desc[group].bg_block_bitmap) { retval = ext2fs_get_free_blocks(fs, start_blk, last_blk, 1, bmap, &new_blk); @@ -66,6 +144,21 @@ errcode_t ext2fs_allocate_group_table(ext2_filsys fs, dgrp_t group, return retval; ext2fs_mark_block_bitmap(bmap, new_blk); fs->group_desc[group].bg_block_bitmap = new_blk; + if (flexbg_size) { + dgrp_t tmp = ext2fs_group_of_blk(fs, new_blk); + bgd_set_flex_meta_flag(fs, new_blk); + fs->group_desc[tmp].bg_free_blocks_count--; + fs->super->s_free_blocks_count--; + } + } + + if (flexbg_size) { + int prev_block = 0; + if (group && fs->group_desc[group-1].bg_inode_bitmap) + prev_block = fs->group_desc[group-1].bg_inode_bitmap; + start_blk = flexbg_offset(fs, group, prev_block, bmap, + flexbg_size, rem_grps); + last_blk = ext2fs_group_last_block(fs, last_grp); } if (!fs->group_desc[group].bg_inode_bitmap) { @@ -78,11 +171,27 @@ errcode_t ext2fs_allocate_group_table(ext2_filsys fs, dgrp_t group, return retval; ext2fs_mark_block_bitmap(bmap, new_blk); fs->group_desc[group].bg_inode_bitmap = new_blk; + if (flexbg_size) { + dgrp_t tmp = ext2fs_group_of_blk(fs, new_blk); + bgd_set_flex_meta_flag(fs, new_blk); + fs->group_desc[tmp].bg_free_blocks_count--; + fs->super->s_free_blocks_count--; + } } /* * Allocate the inode table */ + if (flexbg_size) { + int prev_block = 0; + if (group && fs->group_desc[group-1].bg_inode_table) + prev_block = fs->group_desc[group-1].bg_inode_table; + group_blk = flexbg_offset(fs, group, prev_block, bmap, + flexbg_size * 2, + fs->inode_blocks_per_group * rem_grps); + last_blk = ext2fs_group_last_block(fs, last_grp); + } + if (!fs->group_desc[group].bg_inode_table) { retval = ext2fs_get_free_blocks(fs, group_blk, last_blk, fs->inode_blocks_per_group, @@ -91,8 +200,15 @@ errcode_t ext2fs_allocate_group_table(ext2_filsys fs, dgrp_t group, return retval; for (j=0, blk = new_blk; j < fs->inode_blocks_per_group; - j++, blk++) + j++, blk++) { ext2fs_mark_block_bitmap(bmap, blk); + if (flexbg_size) { + dgrp_t tmp = ext2fs_group_of_blk(fs, blk); + bgd_set_flex_meta_flag(fs, blk); + fs->group_desc[tmp].bg_free_blocks_count--; + fs->super->s_free_blocks_count--; + } + } fs->group_desc[group].bg_inode_table = new_blk; } ext2fs_group_desc_csum_set(fs, group); diff --git a/lib/ext2fs/closefs.c b/lib/ext2fs/closefs.c index 086c28a..19fcb5e 100644 --- a/lib/ext2fs/closefs.c +++ b/lib/ext2fs/closefs.c @@ -99,8 +99,9 @@ int ext2fs_super_and_bgd_loc(ext2_filsys fs, numblocks--; } } - - numblocks -= 2 + fs->inode_blocks_per_group; + + if (!fs->super->s_log_groups_per_flex) + numblocks -= 2 + fs->inode_blocks_per_group; if (ret_super_blk) *ret_super_blk = super_blk; diff --git a/lib/ext2fs/ext2_fs.h b/lib/ext2fs/ext2_fs.h index 444211d..29a1bb5 100644 --- a/lib/ext2fs/ext2_fs.h +++ b/lib/ext2fs/ext2_fs.h @@ -174,6 +174,7 @@ struct ext4_group_desc #define EXT2_BG_INODE_UNINIT 0x0001 /* Inode table/bitmap not initialized */ #define EXT2_BG_BLOCK_UNINIT 0x0002 /* Block bitmap not initialized */ #define EXT2_BG_INODE_ZEROED 0x0004 /* On-disk itable initialized to zero */ +#define EXT2_BG_FLEX_METADATA 0x0008 /* FLEX_BG block group contains meta-data */ /* * Data structures used by the directory indexing feature @@ -563,7 +564,10 @@ struct ext2_super_block { __u16 s_mmp_interval; /* # seconds to wait in MMP checking */ __u64 s_mmp_block; /* Block for multi-mount protection */ __u32 s_raid_stripe_width; /* blocks on all data disks (N*stride)*/ - __u32 s_reserved[163]; /* Padding to the end of the block */ + __u8 s_log_groups_per_flex; /* FLEX_BG group size */ + __u8 s_reserved_char_pad; + __u16 s_reserved_pad; /* Padding to next 32bits */ + __u32 s_reserved[162]; /* Padding to the end of the block */ }; /* diff --git a/lib/ext2fs/initialize.c b/lib/ext2fs/initialize.c index c2e00e8..30cbc6c 100644 --- a/lib/ext2fs/initialize.c +++ b/lib/ext2fs/initialize.c @@ -158,6 +158,7 @@ errcode_t ext2fs_initialize(const char *name, int flags, set_field(s_first_meta_bg, 0); set_field(s_raid_stride, 0); /* default stride size: 0 */ set_field(s_raid_stripe_width, 0); /* default stripe width: 0 */ + set_field(s_log_groups_per_flex, 0); set_field(s_flags, 0); if (super->s_feature_incompat & ~EXT2_LIB_FEATURE_INCOMPAT_SUPP) { retval = EXT2_ET_UNSUPP_FEATURE; @@ -366,7 +367,10 @@ ipg_retry: * group, and fill in the correct group statistics for group. * Note that although the block bitmap, inode bitmap, and * inode table have not been allocated (and in fact won't be - * by this routine), they are accounted for nevertheless. + * by this routine), they are accounted for nevertheless. If + * FLEX_BG meta-data grouping is used, only account for the + * superblock and group descriptors (the inode tables and + * bitmaps will be accounted for when allocated). */ super->s_free_blocks_count = 0; for (i = 0; i < fs->group_desc_count; i++) { diff --git a/misc/mke2fs.8.in b/misc/mke2fs.8.in index a32c34a..9cc3895 100644 --- a/misc/mke2fs.8.in +++ b/misc/mke2fs.8.in @@ -26,6 +26,10 @@ mke2fs \- create an ext2/ext3 filesystem .I blocks-per-group ] [ +.B \-G +.I number-of-groups +] +[ .B \-i .I bytes-per-inode ] @@ -232,6 +236,12 @@ option rather than manipulating the number of blocks per group.) This option is generally used by developers who are developing test cases. .TP +.BI \-G " number-of-groups" +Specify the number of block goups that will be packed together to +create one large virtual block group on an ext4 filesystem. This +improves meta-data locality and performance on meta-data heavy +workloads. The number of goups must be a power of 2. +.TP .BI \-i " bytes-per-inode" Specify the bytes/inode ratio. .B mke2fs @@ -425,6 +435,11 @@ Use hashed b-trees to speed up lookups in large directories. .B filetype Store file type information in directory entries. .TP +.B flex_bg +Allow bitmaps and inode tables for a block group to be placed anywhere +on the storage media (use with -G option to group meta-data in order +to create a large virtual block group). +.TP .B has_journal Create an ext3 journal (as if using the .TP diff --git a/misc/mke2fs.c b/misc/mke2fs.c index 857d345..58b4579 100644 --- a/misc/mke2fs.c +++ b/misc/mke2fs.c @@ -97,8 +97,9 @@ static void usage(void) fprintf(stderr, _("Usage: %s [-c|-l filename] [-b block-size] " "[-f fragment-size]\n\t[-i bytes-per-inode] [-I inode-size] " "[-J journal-options]\n" - "\t[-N number-of-inodes] [-m reserved-blocks-percentage] " - "[-o creator-os]\n\t[-g blocks-per-group] [-L volume-label] " + "\t[-G meta group size] [-N number-of-inodes]\n" + "\t[-m reserved-blocks-percentage] [-o creator-os]\n" + "\t[-g blocks-per-group] [-L volume-label] " "[-M last-mounted-directory]\n\t[-O feature[,...]] " "[-r fs-revision] [-E extended-option[,...]]\n" "\t[-T fs-type] [-jnqvFSV] device [blocks-count]\n"), @@ -480,6 +481,9 @@ static void setup_lazy_bg(ext2_filsys fs) i == fs->group_desc_count - 1) continue; + if ((bg->bg_flags & EXT2_BG_FLEX_METADATA)) + continue; + blks = ext2fs_super_and_bgd_loc(fs, i, 0, 0, 0, 0); if (bg->bg_free_blocks_count == blks && bg->bg_flags & EXT2_BG_INODE_UNINIT) { @@ -967,6 +971,7 @@ static void PRS(int argc, char *argv[]) int blocksize = 0; int inode_ratio = 0; int inode_size = 0; + unsigned long flex_bg_size = 0; double reserved_ratio = 5.0; int sector_size = 0; int show_version_only = 0; @@ -1049,7 +1054,7 @@ static void PRS(int argc, char *argv[]) } while ((c = getopt (argc, argv, - "b:cf:g:i:jl:m:no:qr:s:tvE:FI:J:L:M:N:O:R:ST:V")) != EOF) { + "b:cf:g:G:i:jl:m:no:qr:s:tvE:FI:J:L:M:N:O:R:ST:V")) != EOF) { switch (c) { case 'b': blocksize = strtol(optarg, &tmp, 0); @@ -1100,6 +1105,20 @@ static void PRS(int argc, char *argv[]) exit(1); } break; + case 'G': + flex_bg_size = strtoul(optarg, &tmp, 0); + if (*tmp) { + com_err(program_name, 0, + _("Illegal number for Flex_BG size")); + exit(1); + } + if (flex_bg_size < 2 || + (flex_bg_size & (flex_bg_size-1)) != 0) { + com_err(program_name, 0, + _("Flex_BG size must be a power of 2")); + exit(1); + } + break; case 'i': inode_ratio = strtoul(optarg, &tmp, 0); if (inode_ratio < EXT2_MIN_BLOCK_SIZE || @@ -1495,6 +1514,9 @@ static void PRS(int argc, char *argv[]) } } + if (flex_bg_size) + fs_param.s_log_groups_per_flex = int_log2(flex_bg_size); + if (inode_size == 0) { profile_get_integer(profile, "defaults", "inode_size", NULL, 0, &inode_size);