@@ -2913,6 +2913,8 @@ static struct extent_buffer *grab_extent_buffer(
struct folio *folio = page_folio(page);
struct extent_buffer *exists;
+ lockdep_assert_held(&page->mapping->i_private_lock);
+
/*
* For subpage case, we completely rely on radix tree to ensure we
* don't try to insert two ebs for the same bytenr. So here we always
@@ -2980,13 +2982,14 @@ static int check_eb_alignment(struct btrfs_fs_info *fs_info, u64 start)
* The caller needs to free the existing folios and retry using the same order.
*/
static int attach_eb_folio_to_filemap(struct extent_buffer *eb, int i,
+ struct btrfs_subpage *prealloc,
struct extent_buffer **found_eb_ret)
{
struct btrfs_fs_info *fs_info = eb->fs_info;
struct address_space *mapping = fs_info->btree_inode->i_mapping;
const unsigned long index = eb->start >> PAGE_SHIFT;
- struct folio *existing_folio;
+ struct folio *existing_folio = NULL;
int ret;
ASSERT(found_eb_ret);
@@ -2998,7 +3001,7 @@ static int attach_eb_folio_to_filemap(struct extent_buffer *eb, int i,
ret = filemap_add_folio(mapping, eb->folios[i], index + i,
GFP_NOFS | __GFP_NOFAIL);
if (!ret)
- return 0;
+ goto finish;
existing_folio = filemap_lock_folio(mapping, index + i);
/* The page cache only exists for a very short time, just retry. */
@@ -3014,14 +3017,16 @@ static int attach_eb_folio_to_filemap(struct extent_buffer *eb, int i,
return -EAGAIN;
}
- if (fs_info->nodesize < PAGE_SIZE) {
+finish:
+ spin_lock(&mapping->i_private_lock);
+ if (existing_folio && fs_info->nodesize < PAGE_SIZE) {
/*
- * We're going to reuse the existing page, can drop our page
- * and subpage structure now.
+ * We're going to reuse the existing page, can drop our folio
+ * now.
*/
__free_page(folio_page(eb->folios[i], 0));
eb->folios[i] = existing_folio;
- } else {
+ } else if (existing_folio) {
struct extent_buffer *existing_eb;
existing_eb = grab_extent_buffer(fs_info,
@@ -3029,6 +3034,7 @@ static int attach_eb_folio_to_filemap(struct extent_buffer *eb, int i,
if (existing_eb) {
/* The extent buffer still exists, we can use it directly. */
*found_eb_ret = existing_eb;
+ spin_unlock(&mapping->i_private_lock);
folio_unlock(existing_folio);
folio_put(existing_folio);
return 1;
@@ -3037,6 +3043,22 @@ static int attach_eb_folio_to_filemap(struct extent_buffer *eb, int i,
__free_page(folio_page(eb->folios[i], 0));
eb->folios[i] = existing_folio;
}
+ eb->folio_size = folio_size(eb->folios[i]);
+ eb->folio_shift = folio_shift(eb->folios[i]);
+ /* Should not fail, as we have preallocated the memory */
+ ret = attach_extent_buffer_folio(eb, eb->folios[i], prealloc);
+ ASSERT(!ret);
+ /*
+ * To inform we have extra eb under allocation, so that
+ * detach_extent_buffer_page() won't release the folio private
+ * when the eb hasn't yet been inserted into radix tree.
+ *
+ * The ref will be decreased when the eb released the page, in
+ * detach_extent_buffer_page().
+ * Thus needs no special handling in error path.
+ */
+ btrfs_folio_inc_eb_refs(fs_info, eb->folios[i]);
+ spin_unlock(&mapping->i_private_lock);
return 0;
}
@@ -3048,7 +3070,6 @@ struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
int attached = 0;
struct extent_buffer *eb;
struct extent_buffer *existing_eb = NULL;
- struct address_space *mapping = fs_info->btree_inode->i_mapping;
struct btrfs_subpage *prealloc = NULL;
u64 lockdep_owner = owner_root;
bool page_contig = true;
@@ -3114,7 +3135,7 @@ struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
for (int i = 0; i < num_folios; i++) {
struct folio *folio;
- ret = attach_eb_folio_to_filemap(eb, i, &existing_eb);
+ ret = attach_eb_folio_to_filemap(eb, i, prealloc, &existing_eb);
if (ret > 0) {
ASSERT(existing_eb);
goto out;
@@ -3151,24 +3172,6 @@ struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
* and free the allocated page.
*/
folio = eb->folios[i];
- eb->folio_size = folio_size(folio);
- eb->folio_shift = folio_shift(folio);
- spin_lock(&mapping->i_private_lock);
- /* Should not fail, as we have preallocated the memory */
- ret = attach_extent_buffer_folio(eb, folio, prealloc);
- ASSERT(!ret);
- /*
- * To inform we have extra eb under allocation, so that
- * detach_extent_buffer_page() won't release the folio private
- * when the eb hasn't yet been inserted into radix tree.
- *
- * The ref will be decreased when the eb released the page, in
- * detach_extent_buffer_page().
- * Thus needs no special handling in error path.
- */
- btrfs_folio_inc_eb_refs(fs_info, folio);
- spin_unlock(&mapping->i_private_lock);
-
WARN_ON(btrfs_folio_test_dirty(fs_info, folio, eb->start, eb->len));
/*