Btrfs: Allow tree blocks larger than the page size
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index e081558..f658703 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -1963,18 +1963,27 @@
struct page *p;
if (i == 0)
return eb->first_page;
+
i += eb->start >> PAGE_CACHE_SHIFT;
+ if (eb->last_page && eb->last_page->index == i)
+ return eb->last_page;
+
p = find_get_page(eb->first_page->mapping, i);
page_cache_release(p);
+ eb->last_page = p;
return p;
}
+static inline unsigned long num_extent_pages(u64 start, u64 len)
+{
+ return ((start + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT) -
+ (start >> PAGE_CACHE_SHIFT);
+}
struct extent_buffer *alloc_extent_buffer(struct extent_map_tree *tree,
u64 start, unsigned long len,
gfp_t mask)
{
- unsigned long num_pages = ((start + len - 1) >> PAGE_CACHE_SHIFT) -
- (start >> PAGE_CACHE_SHIFT) + 1;
+ unsigned long num_pages = num_extent_pages(start, len);
unsigned long i;
unsigned long index = start >> PAGE_CACHE_SHIFT;
struct extent_buffer *eb;
@@ -1986,7 +1995,7 @@
if (!eb || IS_ERR(eb))
return NULL;
- eb->alloc_addr = __builtin_return_address(0);
+ eb->alloc_addr = (unsigned long)__builtin_return_address(0);
eb->start = start;
eb->len = len;
atomic_set(&eb->refs, 1);
@@ -1994,6 +2003,7 @@
for (i = 0; i < num_pages; i++, index++) {
p = find_or_create_page(mapping, index, mask | __GFP_HIGHMEM);
if (!p) {
+ WARN_ON(1);
/* make sure the free only frees the pages we've
* grabbed a reference on
*/
@@ -2021,8 +2031,7 @@
u64 start, unsigned long len,
gfp_t mask)
{
- unsigned long num_pages = ((start + len - 1) >> PAGE_CACHE_SHIFT) -
- (start >> PAGE_CACHE_SHIFT) + 1;
+ unsigned long num_pages = num_extent_pages(start, len);
unsigned long i;
unsigned long index = start >> PAGE_CACHE_SHIFT;
struct extent_buffer *eb;
@@ -2033,7 +2042,7 @@
if (!eb || IS_ERR(eb))
return NULL;
- eb->alloc_addr = __builtin_return_address(0);
+ eb->alloc_addr = (unsigned long)__builtin_return_address(0);
eb->start = start;
eb->len = len;
atomic_set(&eb->refs, 1);
@@ -2070,8 +2079,7 @@
if (!atomic_dec_and_test(&eb->refs))
return;
- num_pages = ((eb->start + eb->len - 1) >> PAGE_CACHE_SHIFT) -
- (eb->start >> PAGE_CACHE_SHIFT) + 1;
+ num_pages = num_extent_pages(eb->start, eb->len);
if (eb->first_page)
page_cache_release(eb->first_page);
@@ -2094,8 +2102,7 @@
u64 end = start + eb->len - 1;
set = clear_extent_dirty(tree, start, end, GFP_NOFS);
- num_pages = ((eb->start + eb->len - 1) >> PAGE_CACHE_SHIFT) -
- (eb->start >> PAGE_CACHE_SHIFT) + 1;
+ num_pages = num_extent_pages(eb->start, eb->len);
for (i = 0; i < num_pages; i++) {
page = extent_buffer_page(eb, i);
@@ -2145,8 +2152,7 @@
struct page *page;
unsigned long num_pages;
- num_pages = ((eb->start + eb->len - 1) >> PAGE_CACHE_SHIFT) -
- (eb->start >> PAGE_CACHE_SHIFT) + 1;
+ num_pages = num_extent_pages(eb->start, eb->len);
set_extent_uptodate(tree, eb->start, eb->start + eb->len - 1,
GFP_NOFS);
@@ -2191,8 +2197,7 @@
return 0;
}
- num_pages = ((eb->start + eb->len - 1) >> PAGE_CACHE_SHIFT) -
- (eb->start >> PAGE_CACHE_SHIFT) + 1;
+ num_pages = num_extent_pages(eb->start, eb->len);
for (i = 0; i < num_pages; i++) {
page = extent_buffer_page(eb, i);
if (PageUptodate(page)) {
@@ -2267,14 +2272,14 @@
}
EXPORT_SYMBOL(read_extent_buffer);
-int map_extent_buffer(struct extent_buffer *eb, unsigned long start,
- unsigned long min_len,
- char **token, char **map,
- unsigned long *map_start,
- unsigned long *map_len, int km)
+static int __map_extent_buffer(struct extent_buffer *eb, unsigned long start,
+ unsigned long min_len, char **token, char **map,
+ unsigned long *map_start,
+ unsigned long *map_len, int km)
{
size_t offset = start & (PAGE_CACHE_SIZE - 1);
char *kaddr;
+ struct page *p;
size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
unsigned long end_i = (start_offset + start + min_len) >>
@@ -2283,21 +2288,59 @@
if (i != end_i)
return -EINVAL;
- WARN_ON(start > eb->len);
+ if (start >= eb->len) {
+ printk("bad start in map eb start %Lu len %lu caller start %lu min %lu\n", eb->start, eb->len, start, min_len);
+ WARN_ON(1);
+ }
if (i == 0) {
offset = start_offset;
*map_start = 0;
} else {
+ offset = 0;
*map_start = (i << PAGE_CACHE_SHIFT) - start_offset;
}
- kaddr = kmap_atomic(extent_buffer_page(eb, i), km);
+ p = extent_buffer_page(eb, i);
+ WARN_ON(!PageUptodate(p));
+ kaddr = kmap_atomic(p, km);
*token = kaddr;
*map = kaddr + offset;
*map_len = PAGE_CACHE_SIZE - offset;
return 0;
}
+
+int map_extent_buffer(struct extent_buffer *eb, unsigned long start,
+ unsigned long min_len,
+ char **token, char **map,
+ unsigned long *map_start,
+ unsigned long *map_len, int km)
+{
+ int err;
+ int save = 0;
+ if (eb->map_token) {
+ if (start >= eb->map_start &&
+ start + min_len <= eb->map_start + eb->map_len) {
+ *token = eb->map_token;
+ *map = eb->kaddr;
+ *map_start = eb->map_start;
+ *map_len = eb->map_len;
+ return 0;
+ }
+ unmap_extent_buffer(eb, eb->map_token, km);
+ eb->map_token = NULL;
+ save = 1;
+ }
+ err = __map_extent_buffer(eb, start, min_len, token, map,
+ map_start, map_len, km);
+ if (!err && save) {
+ eb->map_token = *token;
+ eb->kaddr = *map;
+ eb->map_start = *map_start;
+ eb->map_len = *map_len;
+ }
+ return err;
+}
EXPORT_SYMBOL(map_extent_buffer);
void unmap_extent_buffer(struct extent_buffer *eb, char *token, int km)
@@ -2574,7 +2617,6 @@
((unsigned long)PAGE_CACHE_SIZE - 1);
src_off_in_page = src_end &
((unsigned long)PAGE_CACHE_SIZE - 1);
-
if (src_i == 0)
src_off_in_page += start_offset;
if (dst_i == 0)
@@ -2582,14 +2624,13 @@
cur = min(len, src_off_in_page + 1);
cur = min(cur, dst_off_in_page + 1);
-
move_pages(extent_buffer_page(dst, dst_i),
extent_buffer_page(dst, src_i),
dst_off_in_page - cur + 1,
src_off_in_page - cur + 1, cur);
- dst_end -= cur - 1;
- src_end -= cur - 1;
+ dst_end -= cur;
+ src_end -= cur;
len -= cur;
}
}