[PATCH v3] ext4: use proper little-endian bitops
From: Akinobu Mita <akinobu.mita@gmail.com>
Date: 2011-06-02 15:51:27
Also in:
lkml
Subsystem:
ext4 file system, filesystems (vfs and infrastructure), the rest · Maintainers:
"Theodore Ts'o", Alexander Viro, Christian Brauner, Linus Torvalds
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>
Cc: linux-ext4@vger.kernel.org
---
v3: squash into a single patch and do not remove ext4_*_bit_atomic() macros
v2: rewritten to keep ext4_*_bit() macros
fs/ext4/ext4.h | 7 ++++---
fs/ext4/ialloc.c | 4 ++--
2 files changed, 6 insertions(+), 5 deletions(-)
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 1921392..cb65177 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h@@ -930,12 +930,13 @@ 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 21bb2f6..e3de479 100644
--- 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;
@@ -729,7 +729,7 @@ 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;
--
1.7.4.4