@@ -1226,17 +1226,16 @@ void mark_buffer_write_io_error(struct buffer_head *bh)
}
EXPORT_SYMBOL(mark_buffer_write_io_error);
-/*
- * Decrement a buffer_head's reference count. If all buffers against a page
- * have zero reference count, are clean and unlocked, and if the page is clean
- * and unlocked then try_to_free_buffers() may strip the buffers from the page
- * in preparation for freeing it (sometimes, rarely, buffers are removed from
- * a page but it ends up not being freed, and buffers may later be reattached).
+/**
+ * __brelse - Release a buffer.
+ * @bh: The buffer to release.
+ *
+ * This variant of brelse() can be called if @bh is guaranteed to not be NULL.
*/
-void __brelse(struct buffer_head * buf)
+void __brelse(struct buffer_head *bh)
{
- if (atomic_read(&buf->b_count)) {
- put_bh(buf);
+ if (atomic_read(&bh->b_count)) {
+ put_bh(bh);
return;
}
WARN(1, KERN_ERR "VFS: brelse: Trying to free free buffer\n");
@@ -303,6 +303,22 @@ static inline void put_bh(struct buffer_head *bh)
atomic_dec(&bh->b_count);
}
+/**
+ * brelse - Release a buffer.
+ * @bh: The buffer to release.
+ *
+ * Decrement a buffer_head's reference count. If @bh is NULL, this
+ * function is a no-op.
+ *
+ * If all buffers on a folio have zero reference count, are clean
+ * and unlocked, and if the folio is unlocked and not under writeback
+ * then try_to_free_buffers() may strip the buffers from the folio in
+ * preparation for freeing it (sometimes, rarely, buffers are removed
+ * from a folio but it ends up not being freed, and buffers may later
+ * be reattached).
+ *
+ * Context: Any context.
+ */
static inline void brelse(struct buffer_head *bh)
{
if (bh)
Move the documentation for __brelse() to brelse(), format it as kernel-doc and update it from talking about pages to folios. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> --- fs/buffer.c | 17 ++++++++--------- include/linux/buffer_head.h | 16 ++++++++++++++++ 2 files changed, 24 insertions(+), 9 deletions(-)