* [PATCH] Ext2/3 forward compatibility: inode size
@ 2002-10-19 1:56 tytso
0 siblings, 0 replies; 2+ messages in thread
From: tytso @ 2002-10-19 1:56 UTC (permalink / raw)
To: linux-kernel
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)
- Ted
# This is a BitKeeper generated patch for the following project:
# Project Name: Linux kernel tree
# This patch format is intended for GNU patch command version 2.5 or higher.
# This patch includes the following deltas:
# ChangeSet 1.817 -> 1.818
# include/linux/ext2_fs.h 1.14 -> 1.15
# include/linux/ext3_fs.h 1.14 -> 1.15
# fs/ext2/super.c 1.34 -> 1.35
# fs/ext3/super.c 1.36 -> 1.37
#
# The following is the BitKeeper ChangeSet Log
# --------------------------------------------
# 02/10/18 tytso@snap.thunk.org 1.818
# 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. This is also a more efficient way of
# storing the descriptors.
# --------------------------------------------
#
diff -Nru a/fs/ext2/super.c b/fs/ext2/super.c
--- a/fs/ext2/super.c Fri Oct 18 20:52:07 2002
+++ b/fs/ext2/super.c Fri Oct 18 20:52:07 2002
@@ -514,12 +514,29 @@
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;
@@ -735,7 +752,8 @@
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 Fri Oct 18 20:52:07 2002
+++ b/fs/ext3/super.c Fri Oct 18 20:52:07 2002
@@ -971,6 +971,23 @@
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)
{
@@ -978,7 +995,7 @@
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;
@@ -1204,7 +1221,8 @@
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 Fri Oct 18 20:52:07 2002
+++ b/include/linux/ext2_fs.h Fri Oct 18 20:52:07 2002
@@ -399,7 +399,8 @@
__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 */
};
/*
@@ -462,10 +463,12 @@
#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 EXT2_FEATURE_COMPAT_EXT_ATTR
-#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 Fri Oct 18 20:52:07 2002
+++ b/include/linux/ext3_fs.h Fri Oct 18 20:52:07 2002
@@ -427,7 +427,8 @@
__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__
@@ -506,10 +507,12 @@
#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 EXT2_FEATURE_COMPAT_EXT_ATTR
#define EXT3_FEATURE_INCOMPAT_SUPP (EXT3_FEATURE_INCOMPAT_FILETYPE| \
- EXT3_FEATURE_INCOMPAT_RECOVER)
+ EXT3_FEATURE_INCOMPAT_RECOVER| \
+ EXT3_FEATURE_INCOMPAT_META_BG)
#define EXT3_FEATURE_RO_COMPAT_SUPP (EXT3_FEATURE_RO_COMPAT_SPARSE_SUPER| \
EXT3_FEATURE_RO_COMPAT_LARGE_FILE| \
EXT3_FEATURE_RO_COMPAT_BTREE_DIR)
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^ permalink raw reply [flat|nested] 2+ messages in thread
* [PATCH] Ext2/3 forward compatibility: inode size
@ 2002-10-19 1:58 tytso
0 siblings, 0 replies; 2+ messages in thread
From: tytso @ 2002-10-19 1:58 UTC (permalink / raw)
To: linux-kernel
This patch allows filesystems with expanded inodes to be mounted.
(compatibility feature flags will be used to control whether or not the
filesystem should be mounted in case the new inode fields will result in
compatibility issues). This allows for future compatibility with newer
versions of ext2fs.
Hopefully this and the dynamic resize forward compatibility patch can
get included for the 2.6 release.
- Ted
# This is a BitKeeper generated patch for the following project:
# Project Name: Linux kernel tree
# This patch format is intended for GNU patch command version 2.5 or higher.
# This patch includes the following deltas:
# ChangeSet 1.818 -> 1.819
# fs/ext2/inode.c 1.49 -> 1.50
# fs/ext2/ialloc.c 1.23 -> 1.24
# fs/ext2/super.c 1.35 -> 1.36
# fs/ext3/inode.c 1.44 -> 1.45
# fs/ext3/super.c 1.37 -> 1.38
# fs/ext2/ext2.h 1.12 -> 1.13
#
# The following is the BitKeeper ChangeSet Log
# --------------------------------------------
# 02/10/18 tytso@snap.thunk.org 1.819
# Ext2/3 forward compatibility: inode size
#
# This patch allows filesystems with expanded inodes to be mounted.
# (compatibility feature flags will be used to control whether or
# not the filesystem should be mounted in case the new inode fields
# will result in compatibility issues).
# --------------------------------------------
#
diff -Nru a/fs/ext2/ext2.h b/fs/ext2/ext2.h
--- a/fs/ext2/ext2.h Fri Oct 18 20:52:23 2002
+++ b/fs/ext2/ext2.h Fri Oct 18 20:52:23 2002
@@ -10,6 +10,7 @@
__u32 i_faddr;
__u8 i_frag_no;
__u8 i_frag_size;
+ __u16 i_state;
__u32 i_file_acl;
__u32 i_dir_acl;
__u32 i_dtime;
@@ -26,6 +27,12 @@
rwlock_t i_meta_lock;
struct inode vfs_inode;
};
+
+/*
+ * Inode dynamic state flags
+ */
+#define EXT2_STATE_NEW 0x00000001 /* inode is newly created */
+
/*
* Function prototypes
diff -Nru a/fs/ext2/ialloc.c b/fs/ext2/ialloc.c
--- a/fs/ext2/ialloc.c Fri Oct 18 20:52:22 2002
+++ b/fs/ext2/ialloc.c Fri Oct 18 20:52:22 2002
@@ -394,6 +394,7 @@
inode->i_flags |= S_DIRSYNC;
inode->i_generation = EXT2_SB(sb)->s_next_generation++;
insert_inode_hash(inode);
+ ei->i_state = EXT2_STATE_NEW;
unlock_super(sb);
if(DQUOT_ALLOC_INODE(inode)) {
diff -Nru a/fs/ext2/inode.c b/fs/ext2/inode.c
--- a/fs/ext2/inode.c Fri Oct 18 20:52:22 2002
+++ b/fs/ext2/inode.c Fri Oct 18 20:52:22 2002
@@ -1028,6 +1028,7 @@
ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl);
ei->i_dtime = 0;
inode->i_generation = le32_to_cpu(raw_inode->i_generation);
+ ei->i_state = 0;
ei->i_next_alloc_block = 0;
ei->i_next_alloc_goal = 0;
ei->i_prealloc_count = 0;
@@ -1092,6 +1093,11 @@
if (IS_ERR(raw_inode))
return -EIO;
+ /* For fields not not tracking in the in-memory inode,
+ * initialise them to zero for new inodes. */
+ if (ei->i_state & EXT2_STATE_NEW)
+ memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size);
+
raw_inode->i_mode = cpu_to_le16(inode->i_mode);
if (!(test_opt(sb, NO_UID32))) {
raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid));
@@ -1162,6 +1168,7 @@
err = -EIO;
}
}
+ ei->i_state &= ~EXT2_STATE_NEW;
brelse (bh);
return err;
}
diff -Nru a/fs/ext2/super.c b/fs/ext2/super.c
--- a/fs/ext2/super.c Fri Oct 18 20:52:22 2002
+++ b/fs/ext2/super.c Fri Oct 18 20:52:22 2002
@@ -676,7 +676,9 @@
} else {
sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
- if (sbi->s_inode_size != EXT2_GOOD_OLD_INODE_SIZE) {
+ if ((sbi->s_inode_size < EXT2_GOOD_OLD_INODE_SIZE) ||
+ (sbi->s_inode_size & (sbi->s_inode_size - 1)) ||
+ (sbi->s_inode_size > blocksize)) {
printk ("EXT2-fs: unsupported inode size: %d\n",
sbi->s_inode_size);
goto failed_mount;
diff -Nru a/fs/ext3/inode.c b/fs/ext3/inode.c
--- a/fs/ext3/inode.c Fri Oct 18 20:52:22 2002
+++ b/fs/ext3/inode.c Fri Oct 18 20:52:23 2002
@@ -2340,6 +2340,11 @@
if (err)
goto out_brelse;
}
+ /* For fields not not tracking in the in-memory inode,
+ * initialise them to zero for new inodes. */
+ if (ei->i_state & EXT3_STATE_NEW)
+ memset(raw_inode, 0, EXT3_SB(inode->i_sb)->s_inode_size);
+
raw_inode->i_mode = cpu_to_le16(inode->i_mode);
if(!(test_opt(inode->i_sb, NO_UID32))) {
raw_inode->i_uid_low = cpu_to_le16(low_16_bits(inode->i_uid));
@@ -2377,15 +2382,6 @@
raw_inode->i_faddr = cpu_to_le32(ei->i_faddr);
raw_inode->i_frag = ei->i_frag_no;
raw_inode->i_fsize = ei->i_frag_size;
-#else
- /* If we are not tracking these fields in the in-memory inode,
- * then preserve them on disk, but still initialise them to zero
- * for new inodes. */
- if (ei->i_state & EXT3_STATE_NEW) {
- raw_inode->i_faddr = 0;
- raw_inode->i_frag = 0;
- raw_inode->i_fsize = 0;
- }
#endif
raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl);
if (!S_ISREG(inode->i_mode)) {
diff -Nru a/fs/ext3/super.c b/fs/ext3/super.c
--- a/fs/ext3/super.c Fri Oct 18 20:52:23 2002
+++ b/fs/ext3/super.c Fri Oct 18 20:52:23 2002
@@ -1159,7 +1159,9 @@
} else {
sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
- if (sbi->s_inode_size != EXT3_GOOD_OLD_INODE_SIZE) {
+ if ((sbi->s_inode_size < EXT3_GOOD_OLD_INODE_SIZE) ||
+ (sbi->s_inode_size & (sbi->s_inode_size - 1)) ||
+ (sbi->s_inode_size > blocksize)) {
printk (KERN_ERR
"EXT3-fs: unsupported inode size: %d\n",
sbi->s_inode_size);
^ permalink raw reply [flat|nested] 2+ messages in thread
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