X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libbcachefs%2Ffifo.h;h=66b945be10c2309a9e758b228b146047b20674e2;hb=8d5e53b88aaafe7c01fc369e52dbd1fc8955a77d;hp=08739d26bd4d0df15f5895187d0585d778ab2430;hpb=4de98a2712764bceb9e0f67b1ac2f2c7862feb77;p=bcachefs-tools-debian

diff --git a/libbcachefs/fifo.h b/libbcachefs/fifo.h
index 08739d2..66b945b 100644
--- a/libbcachefs/fifo.h
+++ b/libbcachefs/fifo.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _BCACHEFS_FIFO_H
 #define _BCACHEFS_FIFO_H
 
@@ -12,7 +13,9 @@ struct {								\
 #define DECLARE_FIFO(type, name)	FIFO(type) name
 
 #define fifo_buf_size(fifo)						\
-	(roundup_pow_of_two((fifo)->size) * sizeof((fifo)->data[0]))
+	((fifo)->size							\
+	 ? roundup_pow_of_two((fifo)->size) * sizeof((fifo)->data[0])	\
+	 : 0)
 
 #define init_fifo(fifo, _size, _gfp)					\
 ({									\
@@ -56,8 +59,13 @@ do {									\
 #define fifo_peek_front(fifo)	((fifo)->data[(fifo)->front & (fifo)->mask])
 #define fifo_peek_back(fifo)	((fifo)->data[((fifo)->back - 1) & (fifo)->mask])
 
+#define fifo_entry_idx_abs(fifo, p)					\
+	((((p) >= &fifo_peek_front(fifo)				\
+	   ? (fifo)->front : (fifo)->back) & ~(fifo)->mask) +		\
+	   (((p) - (fifo)->data)))
+
 #define fifo_entry_idx(fifo, p)	(((p) - &fifo_peek_front(fifo)) & (fifo)->mask)
-#define fifo_idx_entry(fifo, i)	(fifo)->data[((fifo)->front + (i)) & (fifo)->mask]
+#define fifo_idx_entry(fifo, i)	((fifo)->data[((fifo)->front + (i)) & (fifo)->mask])
 
 #define fifo_push_back_ref(f)						\
 	(fifo_full((f)) ? NULL : &(f)->data[(f)->back++ & (f)->mask])
@@ -93,7 +101,7 @@ do {									\
 ({									\
 	bool _r = !fifo_empty((fifo));					\
 	if (_r)								\
-		(i) = (fifo)->data[--(fifo)->back & (fifo)->mask]	\
+		(i) = (fifo)->data[--(fifo)->back & (fifo)->mask];	\
 	_r;								\
 })
 
@@ -103,15 +111,17 @@ do {									\
 #define fifo_peek(fifo)		fifo_peek_front(fifo)
 
 #define fifo_for_each_entry(_entry, _fifo, _iter)			\
-	for (_iter = (_fifo)->front;					\
+	for (typecheck(typeof((_fifo)->front), _iter),			\
+	     (_iter) = (_fifo)->front;					\
 	     ((_iter != (_fifo)->back) &&				\
 	      (_entry = (_fifo)->data[(_iter) & (_fifo)->mask], true));	\
-	     _iter++)
+	     (_iter)++)
 
 #define fifo_for_each_entry_ptr(_ptr, _fifo, _iter)			\
-	for (_iter = (_fifo)->front;					\
+	for (typecheck(typeof((_fifo)->front), _iter),			\
+	     (_iter) = (_fifo)->front;					\
 	     ((_iter != (_fifo)->back) &&				\
 	      (_ptr = &(_fifo)->data[(_iter) & (_fifo)->mask], true));	\
-	     _iter++)
+	     (_iter)++)
 
 #endif /* _BCACHEFS_FIFO_H */