2006-10-11 08:50:47

by Andrew Morton

[permalink] [raw]
Subject: [patch 034/100] ext4 64 bit divide fix

From: Andrew Morton <[email protected]>

With CONFIG_LBD=n, sector_div() expands to a plain old divide. But ext4 is
_not_ passing in a sector_t as the first argument, so...

fs/built-in.o: In function `ext4_get_group_no_and_offset':
fs/ext4/balloc.c:39: undefined reference to `__umoddi3'
fs/ext4/balloc.c:41: undefined reference to `__udivdi3'
fs/built-in.o: In function `find_group_orlov':
fs/ext4/ialloc.c:278: undefined reference to `__udivdi3'
fs/built-in.o: In function `ext4_fill_super':
fs/ext4/super.c:1488: undefined reference to `__udivdi3'
fs/ext4/super.c:1488: undefined reference to `__umoddi3'
fs/ext4/super.c:1594: undefined reference to `__udivdi3'
fs/ext4/super.c:1601: undefined reference to `__umoddi3'

Fix that up by calling do_div() directly.

Also cast the arg to u64. do_div() is only defined on u64, and ext4_fsblk_t
is supposed to be opaque.

Note especially the changes to find_group_orlov(). It was attempting to do

do_div(int, unsigned long long);

which is royally screwed up. Switched it to plain old divide.

Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
---

fs/ext4/balloc.c | 2 +-
fs/ext4/ialloc.c | 6 +++---
fs/ext4/super.c | 4 ++--
3 files changed, 6 insertions(+), 6 deletions(-)

diff -puN fs/ext4/balloc.c~ext4-64-bit-divide-fix fs/ext4/balloc.c
--- a/fs/ext4/balloc.c~ext4-64-bit-divide-fix
+++ a/fs/ext4/balloc.c
@@ -34,7 +34,7 @@ void ext4_get_group_no_and_offset(struct
ext4_grpblk_t offset;

blocknr = blocknr - le32_to_cpu(es->s_first_data_block);
- offset = sector_div(blocknr, EXT4_BLOCKS_PER_GROUP(sb));
+ offset = do_div(blocknr, EXT4_BLOCKS_PER_GROUP(sb));
if (offsetp)
*offsetp = offset;
if (blockgrpp)
diff -puN fs/ext4/ialloc.c~ext4-64-bit-divide-fix fs/ext4/ialloc.c
--- a/fs/ext4/ialloc.c~ext4-64-bit-divide-fix
+++ a/fs/ext4/ialloc.c
@@ -275,7 +275,7 @@ static int find_group_orlov(struct super
avefreei = freei / ngroups;
freeb = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
avefreeb = freeb;
- sector_div(avefreeb, ngroups);
+ do_div(avefreeb, ngroups);
ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);

if ((parent == sb->s_root->d_inode) ||
@@ -305,14 +305,14 @@ static int find_group_orlov(struct super
}

blocks_per_dir = ext4_blocks_count(es) - freeb;
- sector_div(blocks_per_dir, ndirs);
+ do_div(blocks_per_dir, ndirs);

max_dirs = ndirs / ngroups + inodes_per_group / 16;
min_inodes = avefreei - inodes_per_group / 4;
min_blocks = avefreeb - EXT4_BLOCKS_PER_GROUP(sb) / 4;

max_debt = EXT4_BLOCKS_PER_GROUP(sb);
- sector_div(max_debt, max(blocks_per_dir, (ext4_fsblk_t)BLOCK_COST));
+ max_debt /= max_t(int, blocks_per_dir, BLOCK_COST);
if (max_debt * INODE_COST > inodes_per_group)
max_debt = inodes_per_group / INODE_COST;
if (max_debt > 255)
diff -puN fs/ext4/super.c~ext4-64-bit-divide-fix fs/ext4/super.c
--- a/fs/ext4/super.c~ext4-64-bit-divide-fix
+++ a/fs/ext4/super.c
@@ -1485,7 +1485,7 @@ static int ext4_fill_super (struct super
*/
if (blocksize != EXT4_MIN_BLOCK_SIZE) {
logic_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
- offset = sector_div(logic_sb_block, blocksize);
+ offset = do_div(logic_sb_block, blocksize);
} else {
logic_sb_block = sb_block;
}
@@ -1591,7 +1591,7 @@ static int ext4_fill_super (struct super
brelse (bh);
sb_set_blocksize(sb, blocksize);
logic_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
- offset = sector_div(logic_sb_block, blocksize);
+ offset = do_div(logic_sb_block, blocksize);
bh = sb_bread(sb, logic_sb_block);
if (!bh) {
printk(KERN_ERR
_