2004-09-30 13:28:31

by Stephen C. Tweedie

[permalink] [raw]
Subject: [Patch 8/10]: ext3 online resize: remove s_debts

s_debts is currently not used by ext3 (it is created, destroyed and
checked but never set). Remove it for now.

Resurrecting this will require adding it back in changed form. In
existing form it's already unsafe wrt. byte-tearing as it performs
unlocked byte increment/decrement on words which may be being accessed
simultaneously on other CPUs. It is also the only in-memory dynamic
table which needs to be extended by online-resize, so locking it will
require care.

Signed-off-by: Stephen Tweedie <[email protected]>

--- linux-2.6.9-rc2-mm4/fs/ext3/ialloc.c.=K0007=.orig
+++ linux-2.6.9-rc2-mm4/fs/ext3/ialloc.c
@@ -320,8 +320,6 @@ static int find_group_orlov(struct super
desc = ext3_get_group_desc (sb, group, &bh);
if (!desc || !desc->bg_free_inodes_count)
continue;
- if (sbi->s_debts[group] >= max_debt)
- continue;
if (le16_to_cpu(desc->bg_used_dirs_count) >= max_dirs)
continue;
if (le16_to_cpu(desc->bg_free_inodes_count) < min_inodes)
--- linux-2.6.9-rc2-mm4/fs/ext3/super.c.=K0007=.orig
+++ linux-2.6.9-rc2-mm4/fs/ext3/super.c
@@ -400,7 +400,6 @@ void ext3_put_super (struct super_block
for (i = 0; i < sbi->s_gdb_count; i++)
brelse(sbi->s_group_desc[i]);
kfree(sbi->s_group_desc);
- kfree(sbi->s_debts);
brelse(sbi->s_sbh);
#ifdef CONFIG_QUOTA
for (i = 0; i < MAXQUOTAS; i++) {
@@ -1460,13 +1459,6 @@ static int ext3_fill_super (struct super
printk (KERN_ERR "EXT3-fs: not enough memory\n");
goto failed_mount;
}
- sbi->s_debts = kmalloc(sbi->s_groups_count * sizeof(u8),
- GFP_KERNEL);
- if (!sbi->s_debts) {
- printk("EXT3-fs: not enough memory to allocate s_bgi\n");
- goto failed_mount2;
- }
- memset(sbi->s_debts, 0, sbi->s_groups_count * sizeof(u8));

percpu_counter_init(&sbi->s_freeblocks_counter);
percpu_counter_init(&sbi->s_freeinodes_counter);
@@ -1618,7 +1610,6 @@ static int ext3_fill_super (struct super
failed_mount3:
journal_destroy(sbi->s_journal);
failed_mount2:
- kfree(sbi->s_debts);
for (i = 0; i < db_count; i++)
brelse(sbi->s_group_desc[i]);
kfree(sbi->s_group_desc);
--- linux-2.6.9-rc2-mm4/include/linux/ext3_fs_sb.h.=K0007=.orig
+++ linux-2.6.9-rc2-mm4/include/linux/ext3_fs_sb.h
@@ -54,7 +54,6 @@ struct ext3_sb_info {
u32 s_next_generation;
u32 s_hash_seed[4];
int s_def_hash_version;
- u8 *s_debts;
struct percpu_counter s_freeblocks_counter;
struct percpu_counter s_freeinodes_counter;
struct percpu_counter s_dirs_counter;