From: Zhang Yi <yi.zhang@xxxxxxxxxx>
Since we don't add delayed flag in unwritten extents, all of the four
extent status types EXTENT_STATUS_WRITTEN, EXTENT_STATUS_UNWRITTEN,
EXTENT_STATUS_DELAYED and EXTENT_STATUS_HOLE are exclusive now, add
assertion when storing pblock before inserting extent into status tree
and add comment to the status definition.
Suggested-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Zhang Yi <yi.zhang@xxxxxxxxxx>
---
fs/ext4/extents_status.h | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/fs/ext4/extents_status.h b/fs/ext4/extents_status.h
index 3ca40f018994..7d7af642f7b2 100644
--- a/fs/ext4/extents_status.h
+++ b/fs/ext4/extents_status.h
@@ -42,6 +42,10 @@ enum {
#define ES_SHIFT (sizeof(ext4_fsblk_t)*8 - ES_FLAGS)
#define ES_MASK (~((ext4_fsblk_t)0) << ES_SHIFT)
+/*
+ * Besides EXTENT_STATUS_REFERENCED, all these extent type masks
+ * are exclusive, only one type can be set at a time.
+ */
#define EXTENT_STATUS_WRITTEN (1 << ES_WRITTEN_B)
#define EXTENT_STATUS_UNWRITTEN (1 << ES_UNWRITTEN_B)
#define EXTENT_STATUS_DELAYED (1 << ES_DELAYED_B)
@@ -51,7 +55,9 @@ enum {
#define ES_TYPE_MASK ((ext4_fsblk_t)(EXTENT_STATUS_WRITTEN | \
EXTENT_STATUS_UNWRITTEN | \
EXTENT_STATUS_DELAYED | \
- EXTENT_STATUS_HOLE) << ES_SHIFT)
+ EXTENT_STATUS_HOLE))
+
+#define ES_TYPE_VALID(type) ((type) && !((type) & ((type) - 1)))
struct ext4_sb_info;
struct ext4_extent;
@@ -156,7 +162,7 @@ static inline unsigned int ext4_es_status(struct extent_status *es)
static inline unsigned int ext4_es_type(struct extent_status *es)
{
- return (es->es_pblk & ES_TYPE_MASK) >> ES_SHIFT;
+ return (es->es_pblk >> ES_SHIFT) & ES_TYPE_MASK;
}
static inline int ext4_es_is_written(struct extent_status *es)
@@ -228,6 +234,8 @@ static inline void ext4_es_store_pblock_status(struct extent_status *es,
ext4_fsblk_t pb,
unsigned int status)
{
+ WARN_ON_ONCE(!ES_TYPE_VALID(status & ES_TYPE_MASK));
+
es->es_pblk = (((ext4_fsblk_t)status << ES_SHIFT) & ES_MASK) |
(pb & ~ES_MASK);
}
--
2.39.2
