Commit aa02ad67 authored by Aneesh Kumar K.V's avatar Aneesh Kumar K.V Committed by Theodore Ts'o

ext4: Add ext4_find_next_bit()

This function is used by the ext4 multi block allocator patches.

Also add generic_find_next_le_bit
Signed-off-by: 's avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: 's avatarAndrew Morton <akpm@linux-foundation.org>
parent c549a95d
......@@ -310,6 +310,8 @@ static inline int constant_fls(int x)
_find_first_zero_bit_le(p,sz)
#define ext2_find_next_zero_bit(p,sz,off) \
_find_next_zero_bit_le(p,sz,off)
#define ext2_find_next_bit(p, sz, off) \
_find_next_bit_le(p, sz, off)
/*
* Minix is defined to use little-endian byte ordering.
......
......@@ -14,5 +14,7 @@
generic_find_first_zero_le_bit((unsigned long *)(addr), (size))
#define ext2_find_next_zero_bit(addr, size, off) \
generic_find_next_zero_le_bit((unsigned long *)(addr), (size), (off))
#define ext2_find_next_bit(addr, size, off) \
generic_find_next_le_bit((unsigned long *)(addr), (size), (off))
#endif /* _ASM_GENERIC_BITOPS_EXT2_NON_ATOMIC_H_ */
......@@ -20,6 +20,8 @@
#define generic___test_and_clear_le_bit(nr, addr) __test_and_clear_bit(nr, addr)
#define generic_find_next_zero_le_bit(addr, size, offset) find_next_zero_bit(addr, size, offset)
#define generic_find_next_le_bit(addr, size, offset) \
find_next_bit(addr, size, offset)
#elif defined(__BIG_ENDIAN)
......@@ -42,6 +44,8 @@
extern unsigned long generic_find_next_zero_le_bit(const unsigned long *addr,
unsigned long size, unsigned long offset);
extern unsigned long generic_find_next_le_bit(const unsigned long *addr,
unsigned long size, unsigned long offset);
#else
#error "Please fix <asm/byteorder.h>"
......
......@@ -410,6 +410,8 @@ static inline int ext2_find_next_zero_bit(const void *vaddr, unsigned size,
res = ext2_find_first_zero_bit (p, size - 32 * (p - addr));
return (p - addr) * 32 + res;
}
#define ext2_find_next_bit(addr, size, off) \
generic_find_next_le_bit((unsigned long *)(addr), (size), (off))
#endif /* __KERNEL__ */
......
......@@ -294,6 +294,8 @@ static __inline__ unsigned long ext2_find_next_zero_bit(void *addr, unsigned lon
return result + ffz(__swab32(tmp));
}
#define ext2_find_next_bit(addr, size, off) \
generic_find_next_le_bit((unsigned long *)(addr), (size), (off))
#include <asm-generic/bitops/minix.h>
#endif /* __KERNEL__ */
......
......@@ -359,6 +359,8 @@ static __inline__ int test_le_bit(unsigned long nr,
unsigned long generic_find_next_zero_le_bit(const unsigned long *addr,
unsigned long size, unsigned long offset);
unsigned long generic_find_next_le_bit(const unsigned long *addr,
unsigned long size, unsigned long offset);
/* Bitmap functions for the ext2 filesystem */
#define ext2_set_bit(nr,addr) \
......@@ -378,6 +380,8 @@ unsigned long generic_find_next_zero_le_bit(const unsigned long *addr,
#define ext2_find_next_zero_bit(addr, size, off) \
generic_find_next_zero_le_bit((unsigned long*)addr, size, off)
#define ext2_find_next_bit(addr, size, off) \
generic_find_next_le_bit((unsigned long *)addr, size, off)
/* Bitmap functions for the minix filesystem. */
#define minix_test_and_set_bit(nr,addr) \
......
......@@ -772,6 +772,8 @@ static inline int sched_find_first_bit(unsigned long *b)
test_and_clear_bit((nr)^(__BITOPS_WORDSIZE - 8), (unsigned long *)addr)
#define ext2_test_bit(nr, addr) \
test_bit((nr)^(__BITOPS_WORDSIZE - 8), (unsigned long *)addr)
#define ext2_find_next_bit(addr, size, off) \
generic_find_next_le_bit((unsigned long *)(addr), (size), (off))
#ifndef __s390x__
......
......@@ -493,6 +493,7 @@ do { \
#define ext4_test_bit ext2_test_bit
#define ext4_find_first_zero_bit ext2_find_first_zero_bit
#define ext4_find_next_zero_bit ext2_find_next_zero_bit
#define ext4_find_next_bit ext2_find_next_bit
/*
* Maximal mount counts between two filesystem checks
......
......@@ -178,4 +178,47 @@ unsigned long generic_find_next_zero_le_bit(const unsigned long *addr, unsigned
EXPORT_SYMBOL(generic_find_next_zero_le_bit);
unsigned long generic_find_next_le_bit(const unsigned long *addr, unsigned
long size, unsigned long offset)
{
const unsigned long *p = addr + BITOP_WORD(offset);
unsigned long result = offset & ~(BITS_PER_LONG - 1);
unsigned long tmp;
if (offset >= size)
return size;
size -= result;
offset &= (BITS_PER_LONG - 1UL);
if (offset) {
tmp = ext2_swabp(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 = *(p++);
if (tmp)
goto found_middle_swap;
result += BITS_PER_LONG;
size -= BITS_PER_LONG;
}
if (!size)
return result;
tmp = ext2_swabp(p);
found_first:
tmp &= (~0UL >> (BITS_PER_LONG - size));
if (tmp == 0UL) /* Are any bits set? */
return result + size; /* Nope. */
found_middle:
return result + __ffs(tmp);
found_middle_swap:
return result + __ffs(ext2_swab(tmp));
}
EXPORT_SYMBOL(generic_find_next_le_bit);
#endif /* __BIG_ENDIAN */
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