Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 29 Oct 2002 11:37:29 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 29 Oct 2002 11:37:28 -0500 Received: from SNAP.THUNK.ORG ([216.175.175.173]:38880 "EHLO snap.thunk.org") by vger.kernel.org with ESMTP id ; Tue, 29 Oct 2002 11:35:47 -0500 To: torvalds@transmeta.com cc: linux-kernel@vger.kernel.org, akpm@digeo.com Subject: [PATCH] 2/11 Ext2/3 Updates: Extended attributes, ACL, etc. From: tytso@mit.edu Message-Id: Date: Tue, 29 Oct 2002 11:42:09 -0500 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6268 Lines: 165 Ext2/3 forward compatibility: on-line resizing This patch allows forward compatibility with future filesystems which are dynamically grown by using an alternate algorithm for storing the block group descriptors. It's also a bit more efficient, in that it uses just a little bit less disk space. Currently, the ext2 filesystem format requires either relocating the inode table, or reserving space in before doing the on-line resize. The new scheme, which is documented in "Planned Extensions to the Ext2/3 Filesystem", by Stephen Tweedie and I (see: http://www.usenix.org/publications/library/proceedings/usenix02/tech/freenix/tso.html) fs/ext2/super.c | 22 ++++++++++++++++++++-- fs/ext3/super.c | 22 ++++++++++++++++++++-- include/linux/ext2_fs.h | 7 +++++-- include/linux/ext3_fs.h | 6 +++++- 4 files changed, 50 insertions(+), 7 deletions(-) diff -Nru a/fs/ext2/super.c b/fs/ext2/super.c --- a/fs/ext2/super.c Tue Oct 29 09:54:31 2002 +++ b/fs/ext2/super.c Tue Oct 29 09:54:31 2002 @@ -476,12 +476,29 @@ return res; } +static unsigned long descriptor_loc(struct super_block *sb, + unsigned long logic_sb_block, + int nr) +{ + struct ext2_sb_info *sbi = EXT2_SB(sb); + unsigned long bg, first_data_block, first_meta_bg; + + first_data_block = le32_to_cpu(sbi->s_es->s_first_data_block); + first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg); + + if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) || + nr < first_meta_bg) + return (logic_sb_block + nr + 1); + bg = sbi->s_desc_per_block * nr; + return (first_data_block + 1 + (bg * sbi->s_blocks_per_group)); +} + static int ext2_fill_super(struct super_block *sb, void *data, int silent) { struct buffer_head * bh; struct ext2_sb_info * sbi; struct ext2_super_block * es; - unsigned long sb_block = 1; + unsigned long block, sb_block = 1; unsigned long logic_sb_block = get_sb_block(&data); unsigned long offset = 0; unsigned long def_mount_opts; @@ -689,7 +706,8 @@ goto failed_mount; } for (i = 0; i < db_count; i++) { - sbi->s_group_desc[i] = sb_bread(sb, logic_sb_block + i + 1); + block = descriptor_loc(sb, logic_sb_block, i); + sbi->s_group_desc[i] = sb_bread(sb, block); if (!sbi->s_group_desc[i]) { for (j = 0; j < i; j++) brelse (sbi->s_group_desc[j]); diff -Nru a/fs/ext3/super.c b/fs/ext3/super.c --- a/fs/ext3/super.c Tue Oct 29 09:54:31 2002 +++ b/fs/ext3/super.c Tue Oct 29 09:54:31 2002 @@ -929,6 +929,23 @@ return res; } +static unsigned long descriptor_loc(struct super_block *sb, + unsigned long logic_sb_block, + int nr) +{ + struct ext3_sb_info *sbi = EXT3_SB(sb); + unsigned long bg, first_data_block, first_meta_bg; + + first_data_block = le32_to_cpu(sbi->s_es->s_first_data_block); + first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg); + + if (!EXT3_HAS_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_META_BG) || + nr < first_meta_bg) + return (logic_sb_block + nr + 1); + bg = sbi->s_desc_per_block * nr; + return (first_data_block + 1 + (bg * sbi->s_blocks_per_group)); +} + static int ext3_fill_super (struct super_block *sb, void *data, int silent) { @@ -936,7 +953,7 @@ struct ext3_super_block *es = 0; struct ext3_sb_info *sbi; unsigned long sb_block = get_sb_block(&data); - unsigned long logic_sb_block = 1; + unsigned long block, logic_sb_block = 1; unsigned long offset = 0; unsigned long journal_inum = 0; unsigned long def_mount_opts; @@ -1161,7 +1178,8 @@ goto failed_mount; } for (i = 0; i < db_count; i++) { - sbi->s_group_desc[i] = sb_bread(sb, logic_sb_block + i + 1); + block = descriptor_loc(sb, logic_sb_block, i); + sbi->s_group_desc[i] = sb_bread(sb, block); if (!sbi->s_group_desc[i]) { printk (KERN_ERR "EXT3-fs: " "can't read group descriptor %d\n", i); diff -Nru a/include/linux/ext2_fs.h b/include/linux/ext2_fs.h --- a/include/linux/ext2_fs.h Tue Oct 29 09:54:31 2002 +++ b/include/linux/ext2_fs.h Tue Oct 29 09:54:31 2002 @@ -422,7 +422,8 @@ __u8 s_reserved_char_pad; __u16 s_reserved_word_pad; __u32 s_default_mount_opts; - __u32 s_reserved[191]; /* Padding to the end of the block */ + __u32 s_first_meta_bg; /* First metablock block group */ + __u32 s_reserved[190]; /* Padding to the end of the block */ }; /* @@ -485,10 +486,12 @@ #define EXT2_FEATURE_INCOMPAT_FILETYPE 0x0002 #define EXT3_FEATURE_INCOMPAT_RECOVER 0x0004 #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV 0x0008 +#define EXT2_FEATURE_INCOMPAT_META_BG 0x0010 #define EXT2_FEATURE_INCOMPAT_ANY 0xffffffff #define EXT2_FEATURE_COMPAT_SUPP 0 -#define EXT2_FEATURE_INCOMPAT_SUPP EXT2_FEATURE_INCOMPAT_FILETYPE +#define EXT2_FEATURE_INCOMPAT_SUPP (EXT2_FEATURE_INCOMPAT_FILETYPE| \ + EXT2_FEATURE_INCOMPAT_META_BG) #define EXT2_FEATURE_RO_COMPAT_SUPP (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \ EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \ EXT2_FEATURE_RO_COMPAT_BTREE_DIR) diff -Nru a/include/linux/ext3_fs.h b/include/linux/ext3_fs.h --- a/include/linux/ext3_fs.h Tue Oct 29 09:54:31 2002 +++ b/include/linux/ext3_fs.h Tue Oct 29 09:54:31 2002 @@ -450,7 +450,8 @@ __u8 s_reserved_char_pad; __u16 s_reserved_word_pad; __u32 s_default_mount_opts; - __u32 s_reserved[191]; /* Padding to the end of the block */ + __u32 s_first_meta_bg; /* First metablock block group */ + __u32 s_reserved[190]; /* Padding to the end of the block */ }; #ifdef __KERNEL__ @@ -529,8 +530,11 @@ #define EXT3_FEATURE_INCOMPAT_FILETYPE 0x0002 #define EXT3_FEATURE_INCOMPAT_RECOVER 0x0004 /* Needs recovery */ #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV 0x0008 /* Journal device */ +#define EXT3_FEATURE_INCOMPAT_META_BG 0x0010 #define EXT3_FEATURE_COMPAT_SUPP 0 +#define EXT2_FEATURE_INCOMPAT_SUPP (EXT2_FEATURE_INCOMPAT_FILETYPE| \ + EXT2_FEATURE_INCOMPAT_META_BG) #define EXT3_FEATURE_INCOMPAT_SUPP (EXT3_FEATURE_INCOMPAT_FILETYPE| \ EXT3_FEATURE_INCOMPAT_RECOVER) #define EXT3_FEATURE_RO_COMPAT_SUPP (EXT3_FEATURE_RO_COMPAT_SPARSE_SUPER| \ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/