Btrfs: Add back metadata checksumming

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 68 insertions, 15 deletions

diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index f8aaba8a30a..2a8bc4bd43a 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;