From: Jonathan E Brassow <jbrassow@xxxxxxxxxx>
This patch adds the ability to specify desired features in the mirror
constructor/mapping table.
The first feature of interest is "handle_errors". Currently, mirroring
will ignore any I/O errors from the devices. Subsequent patches will
check for this flag and handle the errors. If flag/feature is not
present, mirror will do nothing - maintaining backwards compatibility.
Signed-off-by: Jonathan E Brassow <jbrassow@xxxxxxxxxx>
Signed-off-by: Alasdair G Kergon <agk@xxxxxxxxxx>
---
drivers/md/dm-raid1.c | 65 ++++++++++++++++++++++++++++++++++++++++++++++++--
1 files changed, 63 insertions(+), 2 deletions(-)
Index: linux-2.6.21/drivers/md/dm-raid1.c
===================================================================
--- linux-2.6.21.orig/drivers/md/dm-raid1.c 2007-05-01 17:40:51.000000000 +0100
+++ linux-2.6.21/drivers/md/dm-raid1.c 2007-05-01 17:40:51.000000000 +0100
@@ -22,6 +22,8 @@
#define DM_MSG_PREFIX "raid1"
+#define DM_RAID1_HANDLE_ERRORS 0x01
+
static DECLARE_WAIT_QUEUE_HEAD(_kmirrord_recovery_stopped);
/*-----------------------------------------------------------------
@@ -118,6 +120,7 @@ struct mirror_set {
struct list_head list;
struct region_hash rh;
struct kcopyd_client *kcopyd_client;
+ uint64_t features;
spinlock_t lock; /* protects the next two lists */
struct bio_list reads;
@@ -1010,14 +1013,54 @@ static struct dirty_log *create_dirty_lo
return dl;
}
+static int parse_features(struct mirror_set *ms, unsigned argc, char **argv,
+ unsigned *args_used)
+{
+ unsigned num_features;
+ struct dm_target *ti = ms->ti;
+
+ *args_used = 0;
+
+ if (!argc)
+ return 0;
+
+ if (sscanf(argv[0], "%u", &num_features) != 1) {
+ ti->error = "Invalid number of features";
+ return -EINVAL;
+ }
+
+ argc--;
+ argv++;
+ (*args_used)++;
+
+ if (num_features > argc) {
+ ti->error = "Not enough arguments to support feature count";
+ return -EINVAL;
+ }
+
+ if (!strcmp("handle_errors", argv[0]))
+ ms->features |= DM_RAID1_HANDLE_ERRORS;
+ else {
+ ti->error = "Unrecognised feature requested";
+ return -EINVAL;
+ }
+
+ (*args_used)++;
+
+ return 0;
+}
+
/*
* Construct a mirror mapping:
*
* log_type #log_params <log_params>
* #mirrors [mirror_path offset]{2,}
+ * [#features <features>]
*
* log_type is "core" or "disk"
* #log_params is between 1 and 3
+ *
+ * If present, features must be "handle_errors".
*/
#define DM_IO_PAGES 64
static int mirror_ctr(struct dm_target *ti, unsigned int argc, char **argv)
@@ -1043,8 +1086,8 @@ static int mirror_ctr(struct dm_target *
argv++, argc--;
- if (argc != nr_mirrors * 2) {
- ti->error = "Wrong number of mirror arguments";
+ if (argc < nr_mirrors * 2) {
+ ti->error = "Too few mirror arguments";
dm_destroy_dirty_log(dl);
return -EINVAL;
}
@@ -1077,6 +1120,21 @@ static int mirror_ctr(struct dm_target *
}
INIT_WORK(&ms->kmirrord_work, do_mirror);
+ r = parse_features(ms, argc, argv, &args_used);
+ if (r) {
+ free_context(ms, ti, ms->nr_mirrors);
+ return r;
+ }
+
+ argv += args_used;
+ argc -= args_used;
+
+ if (argc) {
+ ti->error = "Too many mirror arguments";
+ free_context(ms, ti, ms->nr_mirrors);
+ return -EINVAL;
+ }
+
r = kcopyd_client_create(DM_IO_PAGES, &ms->kcopyd_client);
if (r) {
destroy_workqueue(ms->kmirrord_wq);
@@ -1230,6 +1288,9 @@ static int mirror_status(struct dm_targe
for (m = 0; m < ms->nr_mirrors; m++)
DMEMIT(" %s %llu", ms->mirror[m].dev->name,
(unsigned long long)ms->mirror[m].offset);
+
+ if (ms->features & DM_RAID1_HANDLE_ERRORS)
+ DMEMIT(" 1 handle_errors");
}
return 0;
--
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