[PATCH] Add size option to sanlock direct dump

[Nir Soffer]

Previously "sanlock direct dump" would stop when the first unused space
was found in a lockspace or resource area. For example:

    $ sanlock direct init -r lockspace:A:leases:0
    $ sanlock direct init -r lockspace:B:leases:3145728

    $ sanlock direct dump leases
      offset    lockspace    resource  timestamp  own  gen lver
    00000000    lockspace           A 0000000000 0000 0000 0

This patch adds optional size option. If specified, dump will search up
to size bytes:

    $ sanlock direct dump leases:0:10485760
      offset    lockspace    resource  timestamp  own  gen lver
    00000000    lockspace           A 0000000000 0000 0000 0
    03145728    lockspace           B 0000000000 0000 0000 0

Signed-off-by: Nir Soffer <nsoffer(a)redhat.com&gt;
---
 src/direct.c  | 13 +++++++++++--
 src/main.c    |  2 +-
 src/sanlock.8 |  2 +-
 3 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/src/direct.c b/src/direct.c
index 8fd6e10..09ba417 100644
--- a/src/direct.c
+++ b/src/direct.c
@@ -407,16 +407,23 @@ int direct_dump(struct task *task, char *dump_path, int force_mode)
 	char sname[NAME_ID_SIZE+1];
 	char rname[NAME_ID_SIZE+1];
 	uint64_t sector_nr;
+	uint64_t dump_size = 0;
+	uint64_t end_sector_nr;
 	int sector_count, datalen, align_size;
 	int i, rv, b;
 
 	memset(&sd, 0, sizeof(struct sync_disk));
 
+	/* /path[:<offset>[:<size>]] */
 	colon = strstr(dump_path, ":");
 	if (colon) {
 		off_str = colon + 1;
 		*colon = '\0';
 		sd.offset = atoll(off_str);
+
+		colon = strstr(off_str, ":");
+		if (colon)
+			dump_size = atoll(colon + 1);
 	}
 
 	strncpy(sd.path, dump_path, SANLK_PATH_LEN);
@@ -455,8 +462,9 @@ int direct_dump(struct task *task, char *dump_path, int force_mode)
 	printf("\n");
 
 	sector_nr = 0;
+	end_sector_nr = dump_size / sd.sector_size;
 
-	while (1) {
+	while (end_sector_nr == 0 || sector_nr < end_sector_nr) {
 		memset(sname, 0, sizeof(rname));
 		memset(rname, 0, sizeof(rname));
 		memset(data, 0, sd.sector_size);
@@ -551,7 +559,8 @@ int direct_dump(struct task *task, char *dump_path, int force_mode)
 				printf("%04u %04llu SH\n", i+1, (unsigned long long)mb.generation);
 			}
 		} else {
-			break;
+			if (end_sector_nr == 0)
+				break;
 		}
 
 		sector_nr += sector_count;
diff --git a/src/main.c b/src/main.c
index ebc1e06..83db458 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1851,7 +1851,7 @@ static void print_usage(void)
 	printf("sanlock direct <action> [-a 0|1] [-o 0|1]\n");
 	printf("sanlock direct init -s LOCKSPACE | -r RESOURCE\n");
 	printf("sanlock direct read_leader -s LOCKSPACE | -r RESOURCE\n");
-	printf("sanlock direct dump <path>[:<offset>]\n");
+	printf("sanlock direct dump <path>[:<offset>[:<size>]]\n");
 	printf("\n");
 	printf("LOCKSPACE =
<lockspace_name>:<host_id>:<path>:<offset>\n");
 	printf("  <lockspace_name>	name of lockspace\n");
diff --git a/src/sanlock.8 b/src/sanlock.8
index 73e48ff..dad85a8 100644
--- a/src/sanlock.8
+++ b/src/sanlock.8
@@ -754,7 +754,7 @@ the single sector of a delta lease, or the first sector of a paxos
lease.
 ./"
 
 .BI "sanlock direct dump" " path" \
-\fR[\fP\fB:\fP\fIoffset\fP\fR]\fP
+\fR[\fP\fB:\fP\fIoffset\fP\fR[\fP\fB:\fP\fIsize\fP\fR]]\fP
 
 Read disk sectors and print leader records for delta or paxos leases.  Add
 -f 1 to print the request record values for paxos leases, and host_ids set
-- 
2.7.4