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| author |   David S. Miller <davem@davemloft.net> | 2012-07-19 12:31:33 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-07-20 13:31:21 -0700 |
| commit | f5b0a8743601a4477419171f5046bd07d1c080a0 (patch) | |
| tree | 92e17ec293c3d0e35a0deda5d3bbf43710fb96ff /include/net/dst.h | |
| parent | ipv4: Adjust semantics of rt->rt_gateway. (diff) | |
| download | linux-dev-f5b0a8743601a4477419171f5046bd07d1c080a0.tar.xz linux-dev-f5b0a8743601a4477419171f5046bd07d1c080a0.zip | |
net: Document dst->obsolete better.
Add a big comment explaining how the field works, and use defines
instead of magic constants for the values assigned to it.
Suggested by Joe Perches.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net/dst.h')
| -rw-r--r-- | include/net/dst.h | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/include/net/dst.h b/include/net/dst.h index 51610468c63d..0df661a0c295 100644 --- a/include/net/dst.h +++ b/include/net/dst.h @@ -65,7 +65,19 @@ struct dst_entry { unsigned short pending_confirm; short error; + + /* A non-zero value of dst->obsolete forces by-hand validation + * of the route entry. Positive values are set by the generic + * dst layer to indicate that the entry has been forcefully + * destroyed. + * + * Negative values are used by the implementation layer code to + * force invocation of the dst_ops->check() method. + */ short obsolete; +#define DST_OBSOLETE_NONE 0 +#define DST_OBSOLETE_DEAD 2 +#define DST_OBSOLETE_FORCE_CHK -1 unsigned short header_len; /* more space at head required */ unsigned short trailer_len; /* space to reserve at tail */ #ifdef CONFIG_IP_ROUTE_CLASSID @@ -359,7 +371,7 @@ extern struct dst_entry *dst_destroy(struct dst_entry *dst); static inline void dst_free(struct dst_entry *dst) { - if (dst->obsolete > 1) + if (dst->obsolete > 0) return; if (!atomic_read(&dst->__refcnt)) { dst = dst_destroy(dst); |