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ext4: use proper little-endian bitops

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ext4_{set,clear}_bit() is defined as __test_and_{set,clear}_bit_le() for
ext4.  Only two ext4_{set,clear}_bit() calls check the return value.  The
rest of calls ignore the return value and they can be replaced with
__{set,clear}_bit_le().

This changes ext4_{set,clear}_bit() from __test_and_{set,clear}_bit_le()
to __{set,clear}_bit_le() and introduces ext4_test_and_{set,clear}_bit()
for the two places where old bit needs to be returned.

This ext4_{set,clear}_bit() change is considered safe, because if someone
uses these macros without noticing the change, new ext4_{set,clear}_bit
don't have return value and causes compiler errors where the return value
is used.

This also removes unused ext4_find_first_zero_bit().

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
Akinobu Mita 2011-12-28 20:32:07 -05:00 committed by Theodore Ts'o
parent ccb4d7af91
commit 597d508c17
2 changed files with 6 additions and 5 deletions
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7
fs/ext4/ext4.h
View File

@ -957,12 +957,13 @@ struct ext4_inode_info {
#define test_opt2(sb, opt) (EXT4_SB(sb)->s_mount_opt2 & \
EXT4_MOUNT2_##opt)
#define ext4_set_bit __test_and_set_bit_le
#define ext4_test_and_set_bit __test_and_set_bit_le
#define ext4_set_bit __set_bit_le
#define ext4_set_bit_atomic ext2_set_bit_atomic
#define ext4_clear_bit __test_and_clear_bit_le
#define ext4_test_and_clear_bit __test_and_clear_bit_le
#define ext4_clear_bit __clear_bit_le
#define ext4_clear_bit_atomic ext2_clear_bit_atomic
#define ext4_test_bit test_bit_le
#define ext4_find_first_zero_bit find_first_zero_bit_le
#define ext4_find_next_zero_bit find_next_zero_bit_le
#define ext4_find_next_bit find_next_bit_le

4
fs/ext4/ialloc.c
View File

@ -252,7 +252,7 @@ void ext4_free_inode(handle_t *handle, struct inode *inode)
fatal = ext4_journal_get_write_access(handle, bh2);
}
ext4_lock_group(sb, block_group);
cleared = ext4_clear_bit(bit, bitmap_bh->b_data);
cleared = ext4_test_and_clear_bit(bit, bitmap_bh->b_data);
if (fatal || !cleared) {
ext4_unlock_group(sb, block_group);
goto out;
@ -618,7 +618,7 @@ static int ext4_claim_inode(struct super_block *sb,
*/
down_read(&grp->alloc_sem);
ext4_lock_group(sb, group);
if (ext4_set_bit(ino, inode_bitmap_bh->b_data)) {
if (ext4_test_and_set_bit(ino, inode_bitmap_bh->b_data)) {
/* not a free inode */
retval = 1;
goto err_ret;