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path: root/fs/btrfs/extent_io.c
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Diffstat (limited to 'fs/btrfs/extent_io.c')
-rw-r--r--fs/btrfs/extent_io.c64
1 files changed, 46 insertions, 18 deletions
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index ee40384c394d..66a755150056 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -5558,17 +5558,45 @@ void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
}
}
-/*
- * The extent buffer bitmap operations are done with byte granularity because
- * bitmap items are not guaranteed to be aligned to a word and therefore a
- * single word in a bitmap may straddle two pages in the extent buffer.
- */
-#define BIT_BYTE(nr) ((nr) / BITS_PER_BYTE)
-#define BYTE_MASK ((1 << BITS_PER_BYTE) - 1)
-#define BITMAP_FIRST_BYTE_MASK(start) \
- ((BYTE_MASK << ((start) & (BITS_PER_BYTE - 1))) & BYTE_MASK)
-#define BITMAP_LAST_BYTE_MASK(nbits) \
- (BYTE_MASK >> (-(nbits) & (BITS_PER_BYTE - 1)))
+void le_bitmap_set(u8 *map, unsigned int start, int len)
+{
+ u8 *p = map + BIT_BYTE(start);
+ const unsigned int size = start + len;
+ int bits_to_set = BITS_PER_BYTE - (start % BITS_PER_BYTE);
+ u8 mask_to_set = BITMAP_FIRST_BYTE_MASK(start);
+
+ while (len - bits_to_set >= 0) {
+ *p |= mask_to_set;
+ len -= bits_to_set;
+ bits_to_set = BITS_PER_BYTE;
+ mask_to_set = ~(u8)0;
+ p++;
+ }
+ if (len) {
+ mask_to_set &= BITMAP_LAST_BYTE_MASK(size);
+ *p |= mask_to_set;
+ }
+}
+
+void le_bitmap_clear(u8 *map, unsigned int start, int len)
+{
+ u8 *p = map + BIT_BYTE(start);
+ const unsigned int size = start + len;
+ int bits_to_clear = BITS_PER_BYTE - (start % BITS_PER_BYTE);
+ u8 mask_to_clear = BITMAP_FIRST_BYTE_MASK(start);
+
+ while (len - bits_to_clear >= 0) {
+ *p &= ~mask_to_clear;
+ len -= bits_to_clear;
+ bits_to_clear = BITS_PER_BYTE;
+ mask_to_clear = ~(u8)0;
+ p++;
+ }
+ if (len) {
+ mask_to_clear &= BITMAP_LAST_BYTE_MASK(size);
+ *p &= ~mask_to_clear;
+ }
+}
/*
* eb_bitmap_offset() - calculate the page and offset of the byte containing the
@@ -5612,7 +5640,7 @@ static inline void eb_bitmap_offset(struct extent_buffer *eb,
int extent_buffer_test_bit(struct extent_buffer *eb, unsigned long start,
unsigned long nr)
{
- char *kaddr;
+ u8 *kaddr;
struct page *page;
unsigned long i;
size_t offset;
@@ -5634,13 +5662,13 @@ int extent_buffer_test_bit(struct extent_buffer *eb, unsigned long start,
void extent_buffer_bitmap_set(struct extent_buffer *eb, unsigned long start,
unsigned long pos, unsigned long len)
{
- char *kaddr;
+ u8 *kaddr;
struct page *page;
unsigned long i;
size_t offset;
const unsigned int size = pos + len;
int bits_to_set = BITS_PER_BYTE - (pos % BITS_PER_BYTE);
- unsigned int mask_to_set = BITMAP_FIRST_BYTE_MASK(pos);
+ u8 mask_to_set = BITMAP_FIRST_BYTE_MASK(pos);
eb_bitmap_offset(eb, start, pos, &i, &offset);
page = eb->pages[i];
@@ -5651,7 +5679,7 @@ void extent_buffer_bitmap_set(struct extent_buffer *eb, unsigned long start,
kaddr[offset] |= mask_to_set;
len -= bits_to_set;
bits_to_set = BITS_PER_BYTE;
- mask_to_set = ~0U;
+ mask_to_set = ~(u8)0;
if (++offset >= PAGE_SIZE && len > 0) {
offset = 0;
page = eb->pages[++i];
@@ -5676,13 +5704,13 @@ void extent_buffer_bitmap_set(struct extent_buffer *eb, unsigned long start,
void extent_buffer_bitmap_clear(struct extent_buffer *eb, unsigned long start,
unsigned long pos, unsigned long len)
{
- char *kaddr;
+ u8 *kaddr;
struct page *page;
unsigned long i;
size_t offset;
const unsigned int size = pos + len;
int bits_to_clear = BITS_PER_BYTE - (pos % BITS_PER_BYTE);
- unsigned int mask_to_clear = BITMAP_FIRST_BYTE_MASK(pos);
+ u8 mask_to_clear = BITMAP_FIRST_BYTE_MASK(pos);
eb_bitmap_offset(eb, start, pos, &i, &offset);
page = eb->pages[i];
@@ -5693,7 +5721,7 @@ void extent_buffer_bitmap_clear(struct extent_buffer *eb, unsigned long start,
kaddr[offset] &= ~mask_to_clear;
len -= bits_to_clear;
bits_to_clear = BITS_PER_BYTE;
- mask_to_clear = ~0U;
+ mask_to_clear = ~(u8)0;
if (++offset >= PAGE_SIZE && len > 0) {
offset = 0;
page = eb->pages[++i];