On Tue 13-08-24 20:34:50, Zhang Yi wrote:
> 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>
Looks good. Feel free to add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> 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
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
