10:58 p.m.
In the log filter, all we need to do is copy-and-paste existing
per-command logging to add the initial value of advertised cache
support, as well as logging actual cache commands (well, technically,
this isn't enabled until a later patch flips the default for
.can_cache to pass-through).
Signed-off-by: Eric Blake <eblake(a)redhat.com>
---
filters/log/nbdkit-log-filter.pod | 10 +++++-----
filters/log/log.c | 29 +++++++++++++++++++++++++----
2 files changed, 30 insertions(+), 9 deletions(-)
diff --git a/filters/log/nbdkit-log-filter.pod b/filters/log/nbdkit-log-filter.pod
index 973024b..9e102bc 100644
--- a/filters/log/nbdkit-log-filter.pod
+++ b/filters/log/nbdkit-log-filter.pod
@@ -46,11 +46,11 @@ the impact of the caching.
This filter writes to the file specified by the C<logfile=FILE>
parameter. All lines include a timestamp, a connection counter, then
details about the command. The following actions are logged: Connect,
-Read, Write, Zero, Trim, Extents, Flush, and Disconnect. Except for
-Connect and Disconnect, an event is logged across two lines for call
-and return value, to allow tracking duration and tracing any parallel
-execution, using id for correlation (incremented per action on the
-connection).
+Read, Write, Zero, Trim, Extents, Cache, Flush, and Disconnect.
+Except for Connect and Disconnect, an event is logged across two lines
+for call and return value, to allow tracking duration and tracing any
+parallel execution, using id for correlation (incremented per action
+on the connection).
An example logging session of a client that performs a single
successful read is:
diff --git a/filters/log/log.c b/filters/log/log.c
index 466160e..133e352 100644
--- a/filters/log/log.c
+++ b/filters/log/log.c
@@ -1,5 +1,5 @@
/* nbdkit
- * Copyright (C) 2018 Red Hat Inc.
+ * Copyright (C) 2018-2019 Red Hat Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
@@ -243,13 +243,15 @@ log_prepare (struct nbdkit_next_ops *next_ops, void *nxdata, void
*handle)
int z = next_ops->can_zero (nxdata);
int F = next_ops->can_fua (nxdata);
int e = next_ops->can_extents (nxdata);
+ int c = next_ops->can_cache (nxdata);
- if (size < 0 || w < 0 || f < 0 || r < 0 || t < 0 || z < 0 || F < 0
|| e < 0)
+ if (size < 0 || w < 0 || f < 0 || r < 0 || t < 0 || z < 0 || F < 0
||
+ e < 0 || c < 0)
return -1;
output (h, "Connect", 0, "size=0x%" PRIx64 " write=%d flush=%d
"
- "rotational=%d trim=%d zero=%d fua=%d extents=%d",
- size, w, f, r, t, z, F, e);
+ "rotational=%d trim=%d zero=%d fua=%d extents=%d cache=%d",
+ size, w, f, r, t, z, F, e, c);
return 0;
}
@@ -396,6 +398,24 @@ log_extents (struct nbdkit_next_ops *next_ops, void *nxdata,
return r;
}
+/* Cache data. */
+static int
+log_cache (struct nbdkit_next_ops *next_ops, void *nxdata,
+ void *handle, uint32_t count, uint64_t offs, uint32_t flags,
+ int *err)
+{
+ struct handle *h = handle;
+ uint64_t id = get_id (h);
+ int r;
+
+ assert (!flags);
+ output (h, "Cache", id, "offset=0x%" PRIx64 " count=0x%x
...",
+ offs, count);
+ r = next_ops->cache (nxdata, count, offs, flags, err);
+ output_return (h, "...Cache", id, r, err);
+ return r;
+}
+
static struct nbdkit_filter filter = {
.name = "log",
.longname = "nbdkit log filter",
@@ -414,6 +434,7 @@ static struct nbdkit_filter filter = {
.trim = log_trim,
.zero = log_zero,
.extents = log_extents,
+ .cache = log_cache,
};
NBDKIT_REGISTER_FILTER(filter)
--
2.20.1