@@ -2220,7 +2220,7 @@ void extent_write_locked_range(struct inode *inode, const struct folio *locked_f
cur, cur_len, !ret);
mapping_set_error(mapping, ret);
}
- btrfs_folio_unlock_writer(fs_info, folio, cur, cur_len);
+ btrfs_folio_end_writer_lock(fs_info, folio, cur, cur_len);
if (ret < 0)
found_error = true;
next_page:
@@ -378,13 +378,47 @@ int btrfs_folio_start_writer_lock(const struct btrfs_fs_info *fs_info,
return 0;
}
+/*
+ * Handle different locked folios:
+ *
+ * - Non-subpage folio
+ * Just unlock it.
+ *
+ * - folio locked but without any subpage locked
+ * This happens either before writepage_delalloc() or the delalloc range is
+ * already handled by previous folio.
+ * We can simple unlock it.
+ *
+ * - folio locked with subpage range locked.
+ * We go through the locked sectors inside the range and clear their locked
+ * bitmap, reduce the writer lock number, and unlock the page if that's
+ * the last locked range.
+ */
void btrfs_folio_end_writer_lock(const struct btrfs_fs_info *fs_info,
struct folio *folio, u64 start, u32 len)
{
+ struct btrfs_subpage *subpage = folio_get_private(folio);
+
+ ASSERT(folio_test_locked(folio));
+
if (unlikely(!fs_info) || !btrfs_is_subpage(fs_info, folio->mapping)) {
folio_unlock(folio);
return;
}
+
+ /*
+ * For subpage case, there are two types of locked page. With or
+ * without writers number.
+ *
+ * Since we own the page lock, no one else could touch subpage::writers
+ * and we are safe to do several atomic operations without spinlock.
+ */
+ if (atomic_read(&subpage->writers) == 0) {
+ /* No writers, locked by plain lock_page() */
+ folio_unlock(folio);
+ return;
+ }
+
btrfs_subpage_clamp_range(folio, &start, &len);
if (btrfs_subpage_end_and_test_writer(fs_info, folio, start, len))
folio_unlock(folio);
@@ -702,53 +736,6 @@ void btrfs_folio_assert_not_dirty(const struct btrfs_fs_info *fs_info,
spin_unlock_irqrestore(&subpage->lock, flags);
}
-/*
- * Handle different locked pages with different page sizes:
- *
- * - Page locked by plain lock_page()
- * It should not have any subpage::writers count.
- * Can be unlocked by unlock_page().
- * This is the most common locked page for extent_writepage() called
- * inside extent_write_cache_pages().
- * Rarer cases include the @locked_page from extent_write_locked_range().
- *
- * - Page locked by lock_delalloc_pages()
- * There is only one caller, all pages except @locked_page for
- * extent_write_locked_range().
- * In this case, we have to call subpage helper to handle the case.
- */
-void btrfs_folio_unlock_writer(struct btrfs_fs_info *fs_info,
- struct folio *folio, u64 start, u32 len)
-{
- struct btrfs_subpage *subpage;
-
- ASSERT(folio_test_locked(folio));
- /* For non-subpage case, we just unlock the page */
- if (!btrfs_is_subpage(fs_info, folio->mapping)) {
- folio_unlock(folio);
- return;
- }
-
- ASSERT(folio_test_private(folio) && folio_get_private(folio));
- subpage = folio_get_private(folio);
-
- /*
- * For subpage case, there are two types of locked page. With or
- * without writers number.
- *
- * Since we own the page lock, no one else could touch subpage::writers
- * and we are safe to do several atomic operations without spinlock.
- */
- if (atomic_read(&subpage->writers) == 0) {
- /* No writers, locked by plain lock_page() */
- folio_unlock(folio);
- return;
- }
-
- /* Have writers, use proper subpage helper to end it */
- btrfs_folio_end_writer_lock(fs_info, folio, start, len);
-}
-
/*
* This is for folio already locked by plain lock_page()/folio_lock(), which
* doesn't have any subpage awareness.
@@ -155,8 +155,6 @@ bool btrfs_subpage_clear_and_test_dirty(const struct btrfs_fs_info *fs_info,
void btrfs_folio_assert_not_dirty(const struct btrfs_fs_info *fs_info,
struct folio *folio, u64 start, u32 len);
-void btrfs_folio_unlock_writer(struct btrfs_fs_info *fs_info,
- struct folio *folio, u64 start, u32 len);
void btrfs_get_subpage_dirty_bitmap(struct btrfs_fs_info *fs_info,
struct folio *folio,
unsigned long *ret_bitmap);
The function btrfs_folio_unlock_writer() is already calling btrfs_folio_end_writer_lock() to do the heavy lifting work, the only missing 0 writer check. Thus there is no need to keep two different functions, move the 0 writer check into btrfs_folio_end_writer_lock(), and remove btrfs_folio_unlock_writer(). Signed-off-by: Qu Wenruo <wqu@suse.com> --- fs/btrfs/extent_io.c | 2 +- fs/btrfs/subpage.c | 81 +++++++++++++++++++------------------------- fs/btrfs/subpage.h | 2 -- 3 files changed, 35 insertions(+), 50 deletions(-)