xfs: normalize "infinite" retries in error configs

As it stands today, the "fail immediately" vs. "retry forever"
values for max_retries and retry_timeout_seconds in the xfs metadata
error configurations are not consistent.

A retry_timeout_seconds of 0 means "retry forever," but a
max_retries of 0 means "fail immediately."

retry_timeout_seconds < 0 is disallowed, while max_retries == -1
means "retry forever."

Make this consistent across the error configs, such that a value of
0 means "fail immediately" (i.e. wait 0 seconds, or retry 0 times),
and a value of -1 always means "retry forever."

This makes retry_timeout a signed long to accommodate the -1, even
though it stores jiffies.  Given our limit of a 1 day maximum
timeout, this should be sufficient even at much higher HZ values
than we have available today.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

1 files changed, 7 insertions, 1 deletions

diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index b36676cde103..efd4a5526f37 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -57,10 +57,16 @@ enum {
 
 #define XFS_ERR_RETRY_FOREVER	-1
 
+/*
+ * Although retry_timeout is in jiffies which is normally an unsigned long,
+ * we limit the retry timeout to 86400 seconds, or one day.  So even a
+ * signed 32-bit long is sufficient for a HZ value up to 24855.  Making it
+ * signed lets us store the special "-1" value, meaning retry forever.
+ */
 struct xfs_error_cfg {
 	struct xfs_kobj	kobj;
 	int		max_retries;
-	unsigned long	retry_timeout;	/* in jiffies, 0 = no timeout */
+	long		retry_timeout;	/* in jiffies, -1 = infinite */
 };
 
 typedef struct xfs_mount {