Messages in this thread Patch in this message |  | | | Date | Wed, 24 Feb 2010 17:21:52 +0100 | | From | Jan Kara <> | | Subject | Re: [PATCH] udf: use ext2_find_next_bit |
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On Tue 23-02-10 23:11:13, Akinobu Mita wrote: > Use ext2_find_next_bit (generic_find_next_le_bit) to find the set bit > in little endian bitmap region. > > Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> > Cc: Jan Kara <jack@suse.cz> I've looked at the code and I think this is wrong. UDF uses 1 for free block in the bitmap and 0 for used one. So you need to use generic_find_next_le_bit... Something like the patch below?
Honza
-- Jan Kara <jack@suse.cz> SUSE Labs, CR --- From bfc8c674188d4be5856e445f9b57e1b7a3dbff6d Mon Sep 17 00:00:00 2001 From: Jan Kara <jack@suse.cz> Date: Wed, 24 Feb 2010 17:18:57 +0100 Subject: [PATCH] udf: Use generic function for bit searching
Use generic_find_next_le_bit to search for bits in bitmap so that we don't duplicate code unnecessarily.
Signed-off-by: Jan Kara <jack@suse.cz> --- fs/udf/balloc.c | 51 ++------------------------------------------------- 1 files changed, 2 insertions(+), 49 deletions(-) diff --git a/fs/udf/balloc.c b/fs/udf/balloc.c index 82372e3..f5ff06c 100644 --- a/fs/udf/balloc.c +++ b/fs/udf/balloc.c @@ -31,55 +31,8 @@ #define udf_clear_bit(nr, addr) ext2_clear_bit(nr, addr) #define udf_set_bit(nr, addr) ext2_set_bit(nr, addr) #define udf_test_bit(nr, addr) ext2_test_bit(nr, addr) -#define udf_find_first_one_bit(addr, size) find_first_one_bit(addr, size) #define udf_find_next_one_bit(addr, size, offset) \ - find_next_one_bit(addr, size, offset) - -#define leBPL_to_cpup(x) leNUM_to_cpup(BITS_PER_LONG, x) -#define leNUM_to_cpup(x, y) xleNUM_to_cpup(x, y) -#define xleNUM_to_cpup(x, y) (le ## x ## _to_cpup(y)) -#define uintBPL_t uint(BITS_PER_LONG) -#define uint(x) xuint(x) -#define xuint(x) __le ## x - -static inline int find_next_one_bit(void *addr, int size, int offset) -{ - uintBPL_t *p = ((uintBPL_t *) addr) + (offset / BITS_PER_LONG); - int result = offset & ~(BITS_PER_LONG - 1); - unsigned long tmp; - - if (offset >= size) - return size; - size -= result; - offset &= (BITS_PER_LONG - 1); - if (offset) { - tmp = leBPL_to_cpup(p++); - tmp &= ~0UL << offset; - if (size < BITS_PER_LONG) - goto found_first; - if (tmp) - goto found_middle; - size -= BITS_PER_LONG; - result += BITS_PER_LONG; - } - while (size & ~(BITS_PER_LONG - 1)) { - tmp = leBPL_to_cpup(p++); - if (tmp) - goto found_middle; - result += BITS_PER_LONG; - size -= BITS_PER_LONG; - } - if (!size) - return result; - tmp = leBPL_to_cpup(p); -found_first: - tmp &= ~0UL >> (BITS_PER_LONG - size); -found_middle: - return result + ffz(~tmp); -} - -#define find_first_one_bit(addr, size)\ - find_next_one_bit((addr), (size), 0) + generic_find_next_le_bit((unsigned long *)addr, size, offset) static int read_block_bitmap(struct super_block *sb, struct udf_bitmap *bitmap, unsigned int block, @@ -356,7 +309,7 @@ repeat: break; } } else { - bit = udf_find_next_one_bit((char *)bh->b_data, + bit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3, group_start << 3); if (bit < sb->s_blocksize << 3) -- 1.6.4.2
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