ext4: use proper little-endian bitops

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>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 5b0e26a1272dcc6c6573463767f8563ec683e6e3..41c9ef17acf84b6b7fb2328b5b7f214c7034aad9 100644 (file)
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -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
 

diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index 00beb4f9cc4ff0501012b8bdf338541fcb5e5a69..e4f356f0780d343ed5b0bd1719da63e4d7efc9e5 100644 (file)
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -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;