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Btrfs: Cache extent buffer mappings 

Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Chris Mason 2007-10-15 16:16:28 -04:00
parent db94535db7
commit 14048ed0c4
2 changed files with 49 additions and 6 deletions
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40
fs/btrfs/ctree.h
View File

@ -436,10 +436,18 @@ static inline u##bits btrfs_##name(struct extent_buffer *eb, \
unsigned long map_len; \
unsigned long offset = (unsigned long)s + \
offsetof(type, member); \
err = map_extent_buffer(eb, offset, \
if (eb->map_token && offset >= eb->map_start && \
offset + sizeof(((type *)0)->member) <= eb->map_start + \
eb->map_len) { \
kaddr = eb->kaddr; \
map_start = eb->map_start; \
err = 0; \
} else { \
err = map_extent_buffer(eb, offset, \
sizeof(((type *)0)->member), \
&map_token, &kaddr, \
&map_start, &map_len, KM_USER1); \
} \
if (!err) { \
__le##bits *tmp = (__le##bits *)(kaddr + offset - \
map_start); \
@ -464,10 +472,18 @@ static inline void btrfs_set_##name(struct extent_buffer *eb, \
int unmap_on_exit = (eb->map_token == NULL); \
unsigned long offset = (unsigned long)s + \
offsetof(type, member); \
err = map_extent_buffer(eb, offset, \
if (eb->map_token && offset >= eb->map_start && \
offset + sizeof(((type *)0)->member) <= eb->map_start + \
eb->map_len) { \
kaddr = eb->kaddr; \
map_start = eb->map_start; \
err = 0; \
} else { \
err = map_extent_buffer(eb, offset, \
sizeof(((type *)0)->member), \
&map_token, &kaddr, \
&map_start, &map_len, KM_USER1); \
} \
if (!err) { \
__le##bits *tmp = (__le##bits *)(kaddr + offset - \
map_start); \
@ -490,10 +506,18 @@ static inline u##bits btrfs_##name(struct extent_buffer *eb) \
unsigned long map_len; \
unsigned long offset = offsetof(type, member); \
int unmap_on_exit = (eb->map_token == NULL); \
err = map_extent_buffer(eb, offset, \
if (eb->map_token && offset >= eb->map_start && \
offset + sizeof(((type *)0)->member) <= eb->map_start + \
eb->map_len) { \
kaddr = eb->kaddr; \
map_start = eb->map_start; \
err = 0; \
} else { \
err = map_extent_buffer(eb, offset, \
sizeof(((type *)0)->member), \
&map_token, &kaddr, \
&map_start, &map_len, KM_USER1); \
} \
if (!err) { \
__le##bits *tmp = (__le##bits *)(kaddr + offset - \
map_start); \
@ -517,10 +541,18 @@ static inline void btrfs_set_##name(struct extent_buffer *eb, \
unsigned long map_len; \
unsigned long offset = offsetof(type, member); \
int unmap_on_exit = (eb->map_token == NULL); \
err = map_extent_buffer(eb, offset, \
if (eb->map_token && offset >= eb->map_start && \
offset + sizeof(((type *)0)->member) <= eb->map_start + \
eb->map_len) { \
kaddr = eb->kaddr; \
map_start = eb->map_start; \
err = 0; \
} else { \
err = map_extent_buffer(eb, offset, \
sizeof(((type *)0)->member), \
&map_token, &kaddr, \
&map_start, &map_len, KM_USER1); \
} \
if (!err) { \
__le##bits *tmp = (__le##bits *)(kaddr + offset - \
map_start); \

15
fs/btrfs/extent_map.c
View File

@ -2037,6 +2037,7 @@ struct extent_buffer *find_extent_buffer(struct extent_map_tree *tree,
struct extent_buffer *eb;
struct page *p;
struct address_space *mapping = tree->mapping;
int uptodate = 1;
eb = __alloc_extent_buffer(mask);
if (!eb || IS_ERR(eb))
@ -2048,7 +2049,7 @@ struct extent_buffer *find_extent_buffer(struct extent_map_tree *tree,
atomic_set(&eb->refs, 1);
for (i = 0; i < num_pages; i++, index++) {
p = find_get_page(mapping, index);
p = find_lock_page(mapping, index);
if (!p) {
/* make sure the free only frees the pages we've
* grabbed a reference on
@ -2060,7 +2061,12 @@ struct extent_buffer *find_extent_buffer(struct extent_map_tree *tree,
set_page_extent_mapped(p);
if (i == 0)
eb->first_page = p;
if (!PageUptodate(p))
uptodate = 0;
unlock_page(p);
}
if (uptodate)
eb->flags |= EXTENT_UPTODATE;
return eb;
fail:
free_extent_buffer(eb);
@ -2192,7 +2198,7 @@ int read_extent_buffer_pages(struct extent_map_tree *tree,
if (eb->flags & EXTENT_UPTODATE)
return 0;
if (test_range_bit(tree, eb->start, eb->start + eb->len - 1,
if (0 && test_range_bit(tree, eb->start, eb->start + eb->len - 1,
EXTENT_UPTODATE, 1)) {
return 0;
}
@ -2247,6 +2253,7 @@ void read_extent_buffer(struct extent_buffer *eb, void *dstv,
char *dst = (char *)dstv;
size_t start_offset = eb->start & ((u64)PAGE_CACHE_SIZE - 1);
unsigned long i = (start_offset + start) >> PAGE_CACHE_SHIFT;
unsigned long num_pages = num_extent_pages(eb->start, eb->len);
WARN_ON(start > eb->len);
WARN_ON(start + len > eb->start + eb->len);
@ -2257,6 +2264,10 @@ void read_extent_buffer(struct extent_buffer *eb, void *dstv,
while(len > 0) {
page = extent_buffer_page(eb, i);
if (!PageUptodate(page)) {
printk("page %lu not up to date i %lu, total %lu, len %lu\n", page->index, i, num_pages, eb->len);
WARN_ON(1);
}
WARN_ON(!PageUptodate(page));
cur = min(len, (PAGE_CACHE_SIZE - offset));