From: Valerie Clement Subject: [PATCH 3/8][e2fsprogs] add new -D option to mkfs Date: Thu, 30 Aug 2007 17:37:01 +0200 Message-ID: <1188488221.15770.46.camel@ext1.frec.bull.fr> References: <1188487715.15770.35.camel@ext1.frec.bull.fr> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit To: linux-ext4 , Theodore Ts'o Return-path: Received: from ecfrec.frec.bull.fr ([129.183.4.8]:43736 "EHLO ecfrec.frec.bull.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757874AbXH3N0k (ORCPT ); Thu, 30 Aug 2007 09:26:40 -0400 In-Reply-To: <1188487715.15770.35.camel@ext1.frec.bull.fr> Sender: linux-ext4-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org From: Valerie Clement This patch adds a new option -D to mkfs to allow creating ext4 filesystems with larger group descriptor size. By default, the group descriptor size is 32 bytes. To support 64-bit physical block numbers and thus to be able to use filesystems > 16TB, the group descriptor size must be increased to 64 bytes. Use mkfs -t ext4 -D 64 to create an ext4 filesystem with 64-byte group descriptor size. This set the EXT4_FEATURE_INCOMPAT_64BIT flag on device. The descriptor size is limited to a power-of-two value and to the block size. Signed-off-by: Valerie Clement --- lib/ext2fs/ext2_fs.h | 7 +++++++ lib/ext2fs/initialize.c | 1 + misc/mke2fs.c | 33 +++++++++++++++++++++++++++++++-- 3 files changed, 39 insertions(+), 2 deletions(-) diff --git a/lib/ext2fs/ext2_fs.h b/lib/ext2fs/ext2_fs.h index a316665..f6e8b36 100644 --- a/lib/ext2fs/ext2_fs.h +++ b/lib/ext2fs/ext2_fs.h @@ -217,6 +217,13 @@ struct ext2_dx_countlimit { /* * Macro-instructions used to manage group descriptors */ +#define EXT2_MIN_DESC_SIZE 32 +#define EXT2_MIN_DESC_SIZE_64BIT 64 +#define EXT2_MAX_DESC_SIZE EXT2_MIN_BLOCK_SIZE +#define EXT2_DESC_SIZE(s) \ + ((EXT2_SB(s)->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT) ? \ + (s)->s_desc_size : EXT2_MIN_DESC_SIZE) + #define EXT2_BLOCKS_PER_GROUP(s) (EXT2_SB(s)->s_blocks_per_group) #define EXT2_INODES_PER_GROUP(s) (EXT2_SB(s)->s_inodes_per_group) #define EXT2_INODES_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s)/EXT2_INODE_SIZE(s)) diff --git a/lib/ext2fs/initialize.c b/lib/ext2fs/initialize.c index 16e9eaa..ee7af93 100644 --- a/lib/ext2fs/initialize.c +++ b/lib/ext2fs/initialize.c @@ -149,6 +149,7 @@ errcode_t ext2fs_initialize(const char *name, int flags, set_field(s_log_block_size, 0); /* default blocksize: 1024 bytes */ set_field(s_log_frag_size, 0); /* default fragsize: 1024 bytes */ + set_field(s_desc_size, 0); set_field(s_first_data_block, super->s_log_block_size ? 0 : 1); set_field(s_max_mnt_count, EXT2_DFL_MAX_MNT_COUNT); set_field(s_errors, EXT2_ERRORS_DEFAULT); diff --git a/misc/mke2fs.c b/misc/mke2fs.c index 4a6cace..115eef9 100644 --- a/misc/mke2fs.c +++ b/misc/mke2fs.c @@ -96,7 +96,7 @@ static void usage(void) { fprintf(stderr, _("Usage: %s [-c|-t|-l filename] [-b block-size] " "[-f fragment-size]\n\t[-i bytes-per-inode] [-I inode-size] " - "[-j] [-J journal-options]\n" + "[-D descriptor-size] [-j] [-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] " "[-M last-mounted-directory]\n\t[-O feature[,...]] " @@ -911,6 +911,7 @@ static void PRS(int argc, char *argv[]) int blocksize = 0; int inode_ratio = 0; int inode_size = 0; + int desc_size = 0; double reserved_ratio = 5.0; int sector_size = 0; int show_version_only = 0; @@ -993,7 +994,7 @@ 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:i:jl:m:no:qr:s:tvD:E:FI:J:L:M:N:O:R:ST:V")) != EOF) { switch (c) { case 'b': blocksize = strtol(optarg, &tmp, 0); @@ -1110,6 +1111,14 @@ static void PRS(int argc, char *argv[]) exit(1); } break; + case 'D': + desc_size = strtoul(optarg, &tmp, 0); + if (*tmp) { + com_err(program_name, 0, + _("invalid descriptor size - %s"), optarg); + exit(1); + } + break; case 'v': verbose = 1; break; @@ -1439,6 +1448,26 @@ static void PRS(int argc, char *argv[]) } } + if (desc_size) { + if (desc_size < EXT2_MIN_DESC_SIZE || + desc_size > EXT2_BLOCK_SIZE(&fs_param) || + desc_size & (desc_size -1)) { + com_err(program_name, 0, + _("invalid descriptor size %d (min %d/max %d)"), + desc_size, EXT2_MIN_DESC_SIZE, + blocksize); + exit(1); + } + if (desc_size != EXT2_MIN_DESC_SIZE) + fprintf(stderr, _("Warning: %d-byte descriptors not " + "usable on older systems\n"), + desc_size); + fs_param.s_desc_size = desc_size; + if (desc_size > EXT2_MIN_DESC_SIZE) + fs_param.s_feature_incompat |= EXT4_FEATURE_INCOMPAT_64BIT; + } + + 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"