4:17 p.m.
Typical output:
2019-03-26 18:22:17.287434 connection=2 Extents id=2 offset=0x0 count=0x40000000 req_one=1
...
2019-03-26 18:22:17.290040 connection=2 ...Extents id=2 extents=[{ offset=0x0,
length=0x250000, type=0 }, { offset=0x250000, length=0x7db0000, type=3 }, {
offset=0x8000000, length=0x8000, type=0 }, { offset=0x8008000, length=0x38000, type=3 }, {
offset=0x8040000, length=0x208000, type=0 }, { offset=0x8248000, length=0x7db8000, type=3
}, { offset=0x10000000, length=0x208000, type=0 }, { offset=0x10208000, length=0x7df8000,
type=3 }, { offset=0x18000000, length=0x8000, type=0 }, { offset=0x18008000,
length=0x38000, type=3 }, { offset=0x18040000, length=0x208000, type=0 }, {
offset=0x18248000, length=0x7db8000, type=3 }, { offset=0x20000000, length=0x208000,
type=0 }, { offset=0x20208000, length=0x7df8000, type=3 }, { offset=0x28000000,
length=0x8000, type=0 }, { offset=0x28008000, length=0x38000, type=3 }, {
offset=0x28040000, length=0x208000, type=0 }, { offset=0x28248000, length=0x7db8000,
type=3 }, { offset=0x30000000, length=0x208000, type=0 }, { offset=0x30208000,
length=0x7df8000, type=3 }, { offset=0x38000000, length=0x8000, type=0 }, {
offset=0x38008000, length=0x38000, type=3 }, { offset=0x38040000, length=0x208000, type=0
}, { offset=0x38248000, length=0x7da8000, type=3 }, { offset=0x3fff0000, length=0x10000,
type=0 }] return=0
As you can see this is logging the complete information as generated
by the underlying plugin, not what is returned to the client (which is
rather hard for the log filter to discern). It's probably more useful
for debugging like this.
---
filters/log/log.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 45 insertions(+)
diff --git a/filters/log/log.c b/filters/log/log.c
index 9f2e37d..b31d784 100644
--- a/filters/log/log.c
+++ b/filters/log/log.c
@@ -353,6 +353,50 @@ log_zero (struct nbdkit_next_ops *next_ops, void *nxdata,
return r;
}
+/* Extents. */
+static int
+log_extents (struct nbdkit_next_ops *next_ops, void *nxdata,
+ void *handle, uint32_t count, uint64_t offs, uint32_t flags,
+ struct nbdkit_extents *extents, int *err)
+{
+ struct handle *h = handle;
+ uint64_t id = get_id (h);
+ int r;
+
+ assert (!(flags & ~(NBDKIT_FLAG_REQ_ONE)));
+ output (h, "Extents", id,
+ "offset=0x%" PRIx64 " count=0x%x req_one=%d ...",
+ offs, count, !!(flags & NBDKIT_FLAG_REQ_ONE));
+ r = next_ops->extents (nxdata, count, offs, flags, extents, err);
+ if (r == -1)
+ output_return (h, "...Extents", id, r, err);
+ else {
+ FILE *fp;
+ char *extents_str = NULL;
+ size_t i, n, len = 0;
+
+ fp = open_memstream (&extents_str, &len);
+ if (fp != NULL) {
+ n = nbdkit_extents_count (extents);
+ for (i = 0; i < n; ++i) {
+ struct nbdkit_extent e = nbdkit_get_extent (extents, i);
+ if (i > 0)
+ fprintf (fp, ", ");
+ fprintf (fp, "{ offset=0x%" PRIx64 ", length=0x%" PRIx64
", "
+ "type=%" PRIu32 " }",
+ e.offset, e.length, e.type);
+ }
+
+ fclose (fp);
+ }
+
+ output (h, "...Extents", id, "extents=[%s] return=0",
+ extents_str ? extents_str : "(null)");
+ free (extents_str);
+ }
+ return r;
+}
+
static struct nbdkit_filter filter = {
.name = "log",
.longname = "nbdkit log filter",
@@ -370,6 +414,7 @@ static struct nbdkit_filter filter = {
.flush = log_flush,
.trim = log_trim,
.zero = log_zero,
+ .extents = log_extents,
};
NBDKIT_REGISTER_FILTER(filter)
--
2.20.1