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path: root/fs/btrfs/extent_map.c
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Diffstat (limited to 'fs/btrfs/extent_map.c')
-rw-r--r--fs/btrfs/extent_map.c83
1 files changed, 68 insertions, 15 deletions
diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index f8aaba8a30a2..2a8bc4bd43a9 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -81,7 +81,7 @@ void extent_map_tree_init(struct extent_map_tree *tree,
}
EXPORT_SYMBOL(extent_map_tree_init);
-void extent_map_tree_cleanup(struct extent_map_tree *tree)
+void extent_map_tree_empty_lru(struct extent_map_tree *tree)
{
struct extent_buffer *eb;
while(!list_empty(&tree->buffer_lru)) {
@@ -91,7 +91,7 @@ void extent_map_tree_cleanup(struct extent_map_tree *tree)
free_extent_buffer(eb);
}
}
-EXPORT_SYMBOL(extent_map_tree_cleanup);
+EXPORT_SYMBOL(extent_map_tree_empty_lru);
struct extent_map *alloc_extent_map(gfp_t mask)
{
@@ -1464,7 +1464,7 @@ void set_page_extent_mapped(struct page *page)
if (!PagePrivate(page)) {
SetPagePrivate(page);
WARN_ON(!page->mapping->a_ops->invalidatepage);
- set_page_private(page, 1);
+ set_page_private(page, EXTENT_PAGE_PRIVATE);
page_cache_get(page);
}
}
@@ -1979,8 +1979,9 @@ static struct extent_buffer *__alloc_extent_buffer(struct extent_map_tree *tree,
spin_lock(&tree->lru_lock);
eb = find_lru(tree, start, len);
- if (eb)
+ if (eb) {
goto lru_add;
+ }
spin_unlock(&tree->lru_lock);
if (eb) {
@@ -2007,6 +2008,7 @@ static void __free_extent_buffer(struct extent_buffer *eb)
struct extent_buffer *alloc_extent_buffer(struct extent_map_tree *tree,
u64 start, unsigned long len,
+ struct page *page0,
gfp_t mask)
{
unsigned long num_pages = num_extent_pages(start, len);
@@ -2024,7 +2026,18 @@ struct extent_buffer *alloc_extent_buffer(struct extent_map_tree *tree,
if (eb->flags & EXTENT_BUFFER_FILLED)
return eb;
- for (i = 0; i < num_pages; i++, index++) {
+ if (page0) {
+ eb->first_page = page0;
+ i = 1;
+ index++;
+ page_cache_get(page0);
+ set_page_extent_mapped(page0);
+ set_page_private(page0, EXTENT_PAGE_PRIVATE_FIRST_PAGE |
+ len << 2);
+ } else {
+ i = 0;
+ }
+ for (; i < num_pages; i++, index++) {
p = find_or_create_page(mapping, index, mask | __GFP_HIGHMEM);
if (!p) {
WARN_ON(1);
@@ -2036,8 +2049,13 @@ struct extent_buffer *alloc_extent_buffer(struct extent_map_tree *tree,
goto fail;
}
set_page_extent_mapped(p);
- if (i == 0)
+ if (i == 0) {
eb->first_page = p;
+ set_page_private(p, EXTENT_PAGE_PRIVATE_FIRST_PAGE |
+ len << 2);
+ } else {
+ set_page_private(p, EXTENT_PAGE_PRIVATE);
+ }
if (!PageUptodate(p))
uptodate = 0;
unlock_page(p);
@@ -2057,8 +2075,7 @@ struct extent_buffer *find_extent_buffer(struct extent_map_tree *tree,
gfp_t mask)
{
unsigned long num_pages = num_extent_pages(start, len);
- unsigned long i;
- unsigned long index = start >> PAGE_CACHE_SHIFT;
+ unsigned long i; unsigned long index = start >> PAGE_CACHE_SHIFT;
struct extent_buffer *eb;
struct page *p;
struct address_space *mapping = tree->mapping;
@@ -2082,8 +2099,15 @@ struct extent_buffer *find_extent_buffer(struct extent_map_tree *tree,
goto fail;
}
set_page_extent_mapped(p);
- if (i == 0)
+
+ if (i == 0) {
eb->first_page = p;
+ set_page_private(p, EXTENT_PAGE_PRIVATE_FIRST_PAGE |
+ len << 2);
+ } else {
+ set_page_private(p, EXTENT_PAGE_PRIVATE);
+ }
+
if (!PageUptodate(p))
uptodate = 0;
unlock_page(p);
@@ -2174,7 +2198,21 @@ int set_extent_buffer_dirty(struct extent_map_tree *tree,
num_pages = num_extent_pages(eb->start, eb->len);
for (i = 0; i < num_pages; i++) {
+ struct page *page = extent_buffer_page(eb, i);
+ /* writepage may need to do something special for the
+ * first page, we have to make sure page->private is
+ * properly set. releasepage may drop page->private
+ * on us if the page isn't already dirty.
+ */
+ if (i == 0) {
+ lock_page(page);
+ set_page_private(page,
+ EXTENT_PAGE_PRIVATE_FIRST_PAGE |
+ eb->len << 2);
+ }
__set_page_dirty_nobuffers(extent_buffer_page(eb, i));
+ if (i == 0)
+ unlock_page(page);
}
return set_extent_dirty(tree, eb->start,
eb->start + eb->len - 1, GFP_NOFS);
@@ -2217,9 +2255,12 @@ int extent_buffer_uptodate(struct extent_map_tree *tree,
EXPORT_SYMBOL(extent_buffer_uptodate);
int read_extent_buffer_pages(struct extent_map_tree *tree,
- struct extent_buffer *eb, int wait)
+ struct extent_buffer *eb,
+ u64 start,
+ int wait)
{
unsigned long i;
+ unsigned long start_i;
struct page *page;
int err;
int ret = 0;
@@ -2232,9 +2273,16 @@ int read_extent_buffer_pages(struct extent_map_tree *tree,
EXTENT_UPTODATE, 1)) {
return 0;
}
+ if (start) {
+ WARN_ON(start < eb->start);
+ start_i = (start >> PAGE_CACHE_SHIFT) -
+ (eb->start >> PAGE_CACHE_SHIFT);
+ } else {
+ start_i = 0;
+ }
num_pages = num_extent_pages(eb->start, eb->len);
- for (i = 0; i < num_pages; i++) {
+ for (i = start_i; i < num_pages; i++) {
page = extent_buffer_page(eb, i);
if (PageUptodate(page)) {
continue;
@@ -2260,7 +2308,7 @@ int read_extent_buffer_pages(struct extent_map_tree *tree,
return ret;
}
- for (i = 0; i < num_pages; i++) {
+ for (i = start_i; i < num_pages; i++) {
page = extent_buffer_page(eb, i);
wait_on_page_locked(page);
if (!PageUptodate(page)) {
@@ -2314,7 +2362,7 @@ void read_extent_buffer(struct extent_buffer *eb, void *dstv,
}
EXPORT_SYMBOL(read_extent_buffer);
-static int __map_extent_buffer(struct extent_buffer *eb, unsigned long start,
+int map_private_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)
@@ -2337,6 +2385,10 @@ static int __map_extent_buffer(struct extent_buffer *eb, unsigned long start,
offset = 0;
*map_start = (i << PAGE_CACHE_SHIFT) - start_offset;
}
+ if (start + min_len >= eb->len) {
+printk("bad mapping eb start %Lu len %lu, wanted %lu %lu\n", eb->start, eb->len, start, min_len);
+ WARN_ON(1);
+ }
p = extent_buffer_page(eb, i);
WARN_ON(!PageUptodate(p));
@@ -2346,6 +2398,7 @@ static int __map_extent_buffer(struct extent_buffer *eb, unsigned long start,
*map_len = PAGE_CACHE_SIZE - offset;
return 0;
}
+EXPORT_SYMBOL(map_private_extent_buffer);
int map_extent_buffer(struct extent_buffer *eb, unsigned long start,
unsigned long min_len,
@@ -2360,8 +2413,8 @@ int map_extent_buffer(struct extent_buffer *eb, unsigned long start,
eb->map_token = NULL;
save = 1;
}
- err = __map_extent_buffer(eb, start, min_len, token, map,
- map_start, map_len, km);
+ err = map_private_extent_buffer(eb, start, min_len, token, map,
+ map_start, map_len, km);
if (!err && save) {
eb->map_token = *token;
eb->kaddr = *map;
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-17 01:00:12 +0000