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Merge branch 'freespace-tree' into for-linus-4.5

Browse Source 
Signed-off-by: Chris Mason <clm@fb.com>
This commit is contained in:
Chris Mason
2015-12-18 11:11:10 -08:00
parent 9f9499ae8e 70f6d82ec7
commit f7d3d2f99e
16 changed files with 2934 additions and 113 deletions
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183
fs/btrfs/extent_io.c
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@@ -4797,24 +4797,14 @@ struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src)
return new;
}
struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
u64 start)
struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
u64 start, unsigned long len)
{
struct extent_buffer *eb;
unsigned long len;
unsigned long num_pages;
unsigned long i;
if (!fs_info) {
/*
* Called only from tests that don't always have a fs_info
* available, but we know that nodesize is 4096
*/
len = 4096;
} else {
len = fs_info->tree_root->nodesize;
}
num_pages = num_extent_pages(0, len);
num_pages = num_extent_pages(start, len);
eb = __alloc_extent_buffer(fs_info, start, len);
if (!eb)
@@ -4837,6 +4827,24 @@ err:
return NULL;
}
struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
u64 start)
{
unsigned long len;
if (!fs_info) {
/*
* Called only from tests that don't always have a fs_info
* available, but we know that nodesize is 4096
*/
len = 4096;
} else {
len = fs_info->tree_root->nodesize;
}
return __alloc_dummy_extent_buffer(fs_info, start, len);
}
static void check_buffer_tree_ref(struct extent_buffer *eb)
{
int refs;
@@ -5594,6 +5602,155 @@ 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)))
/*
* eb_bitmap_offset() - calculate the page and offset of the byte containing the
* given bit number
* @eb: the extent buffer
* @start: offset of the bitmap item in the extent buffer
* @nr: bit number
* @page_index: return index of the page in the extent buffer that contains the
* given bit number
* @page_offset: return offset into the page given by page_index
*
* This helper hides the ugliness of finding the byte in an extent buffer which
* contains a given bit.
*/
static inline void eb_bitmap_offset(struct extent_buffer *eb,
unsigned long start, unsigned long nr,
unsigned long *page_index,
size_t *page_offset)
{
size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
size_t byte_offset = BIT_BYTE(nr);
size_t offset;
/*
* The byte we want is the offset of the extent buffer + the offset of
* the bitmap item in the extent buffer + the offset of the byte in the
* bitmap item.
*/
offset = start_offset + start + byte_offset;
*page_index = offset >> PAGE_CACHE_SHIFT;
*page_offset = offset & (PAGE_CACHE_SIZE - 1);
}
/**
* extent_buffer_test_bit - determine whether a bit in a bitmap item is set
* @eb: the extent buffer
* @start: offset of the bitmap item in the extent buffer
* @nr: bit number to test
*/
int extent_buffer_test_bit(struct extent_buffer *eb, unsigned long start,
unsigned long nr)
{
char *kaddr;
struct page *page;
unsigned long i;
size_t offset;
eb_bitmap_offset(eb, start, nr, &i, &offset);
page = eb->pages[i];
WARN_ON(!PageUptodate(page));
kaddr = page_address(page);
return 1U & (kaddr[offset] >> (nr & (BITS_PER_BYTE - 1)));
}
/**
* extent_buffer_bitmap_set - set an area of a bitmap
* @eb: the extent buffer
* @start: offset of the bitmap item in the extent buffer
* @pos: bit number of the first bit
* @len: number of bits to set
*/
void extent_buffer_bitmap_set(struct extent_buffer *eb, unsigned long start,
unsigned long pos, unsigned long len)
{
char *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);
eb_bitmap_offset(eb, start, pos, &i, &offset);
page = eb->pages[i];
WARN_ON(!PageUptodate(page));
kaddr = page_address(page);
while (len >= bits_to_set) {
kaddr[offset] |= mask_to_set;
len -= bits_to_set;
bits_to_set = BITS_PER_BYTE;
mask_to_set = ~0U;
if (++offset >= PAGE_CACHE_SIZE && len > 0) {
offset = 0;
page = eb->pages[++i];
WARN_ON(!PageUptodate(page));
kaddr = page_address(page);
}
}
if (len) {
mask_to_set &= BITMAP_LAST_BYTE_MASK(size);
kaddr[offset] |= mask_to_set;
}
}
/**
* extent_buffer_bitmap_clear - clear an area of a bitmap
* @eb: the extent buffer
* @start: offset of the bitmap item in the extent buffer
* @pos: bit number of the first bit
* @len: number of bits to clear
*/
void extent_buffer_bitmap_clear(struct extent_buffer *eb, unsigned long start,
unsigned long pos, unsigned long len)
{
char *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);
eb_bitmap_offset(eb, start, pos, &i, &offset);
page = eb->pages[i];
WARN_ON(!PageUptodate(page));
kaddr = page_address(page);
while (len >= bits_to_clear) {
kaddr[offset] &= ~mask_to_clear;
len -= bits_to_clear;
bits_to_clear = BITS_PER_BYTE;
mask_to_clear = ~0U;
if (++offset >= PAGE_CACHE_SIZE && len > 0) {
offset = 0;
page = eb->pages[++i];
WARN_ON(!PageUptodate(page));
kaddr = page_address(page);
}
}
if (len) {
mask_to_clear &= BITMAP_LAST_BYTE_MASK(size);
kaddr[offset] &= ~mask_to_clear;
}
}
static inline bool areas_overlap(unsigned long src, unsigned long dst, unsigned long len)
{
unsigned long distance = (src > dst) ? src - dst : dst - src;