Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit f4e5bc24 authored by Andrew Morton's avatar Andrew Morton Committed by Linus Torvalds
Browse files

[PATCH] ext4 64 bit divide fix 



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: <linux-ext4@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 72b64b59

fs/ext4/balloc.c

+1 −1
Original line number Diff line number Diff line
@@ -34,7 +34,7 @@ void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr, 
	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)

fs/ext4/ialloc.c

+3 −3
Original line number Diff line number Diff line
@@ -275,7 +275,7 @@ static int find_group_orlov(struct super_block *sb, struct inode *parent) 
	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_block *sb, struct inode *parent) 
	}



	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)

fs/ext4/super.c

+2 −2
Original line number Diff line number Diff line
@@ -1485,7 +1485,7 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent) 
	 */

	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_block *sb, void *data, int silent) 
		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