Grow: support consistency policy change

Extend the --consistency-policy parameter to work also in Grow mode.
Using it changes the currently active consistency policy in the kernel
driver and updates the metadata to make this change permanent. Currently
this supports only changing between "ppl" and "resync" policies, that is
enabling or disabling PPL at runtime.

Signed-off-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
Signed-off-by: Jes Sorensen <Jes.Sorensen@gmail.com>

1 files changed, 172 insertions, 0 deletions

diff --git a/Grow.c b/Grow.c
index a849012..b86b53e 100755
--- a/Grow.c
+++ b/Grow.c
@@ -528,6 +528,178 @@ int Grow_addbitmap(char *devname, int fd, struct context *c, struct shape *s)
 	return 0;
 }
 
+int Grow_consistency_policy(char *devname, int fd, struct context *c, struct shape *s)
+{
+	struct supertype *st;
+	struct mdinfo *sra;
+	struct mdinfo *sd;
+	char *subarray = NULL;
+	int ret = 0;
+	char container_dev[PATH_MAX];
+
+	if (s->consistency_policy != CONSISTENCY_POLICY_RESYNC &&
+	    s->consistency_policy != CONSISTENCY_POLICY_PPL) {
+		pr_err("Operation not supported for consistency policy %s\n",
+		       map_num(consistency_policies, s->consistency_policy));
+		return 1;
+	}
+
+	st = super_by_fd(fd, &subarray);
+	if (!st)
+		return 1;
+
+	sra = sysfs_read(fd, NULL, GET_CONSISTENCY_POLICY|GET_LEVEL|
+				   GET_DEVS|GET_STATE);
+	if (!sra) {
+		ret = 1;
+		goto free_st;
+	}
+
+	if (s->consistency_policy == CONSISTENCY_POLICY_PPL &&
+	    !st->ss->write_init_ppl) {
+		pr_err("%s metadata does not support PPL\n", st->ss->name);
+		ret = 1;
+		goto free_info;
+	}
+
+	if (sra->array.level != 5) {
+		pr_err("Operation not supported for array level %d\n",
+				sra->array.level);
+		ret = 1;
+		goto free_info;
+	}
+
+	if (sra->consistency_policy == (unsigned)s->consistency_policy) {
+		pr_err("Consistency policy is already %s\n",
+		       map_num(consistency_policies, s->consistency_policy));
+		ret = 1;
+		goto free_info;
+	} else if (sra->consistency_policy != CONSISTENCY_POLICY_RESYNC &&
+		   sra->consistency_policy != CONSISTENCY_POLICY_PPL) {
+		pr_err("Current consistency policy is %s, cannot change to %s\n",
+		       map_num(consistency_policies, sra->consistency_policy),
+		       map_num(consistency_policies, s->consistency_policy));
+		ret = 1;
+		goto free_info;
+	}
+
+	if (subarray) {
+		char *update;
+
+		if (s->consistency_policy == CONSISTENCY_POLICY_PPL)
+			update = "ppl";
+		else
+			update = "no-ppl";
+
+		sprintf(container_dev, "/dev/%s", st->container_devnm);
+
+		ret = Update_subarray(container_dev, subarray, update, NULL,
+				      c->verbose);
+		if (ret)
+			goto free_info;
+	}
+
+	if (s->consistency_policy == CONSISTENCY_POLICY_PPL) {
+		struct mdinfo info;
+
+		if (subarray) {
+			struct mdinfo *mdi;
+			int cfd;
+
+			cfd = open(container_dev, O_RDWR|O_EXCL);
+			if (cfd < 0) {
+				pr_err("Failed to open %s\n", container_dev);
+				ret = 1;
+				goto free_info;
+			}
+
+			ret = st->ss->load_container(st, cfd, st->container_devnm);
+			close(cfd);
+
+			if (ret) {
+				pr_err("Cannot read superblock for %s\n",
+				       container_dev);
+				goto free_info;
+			}
+
+			mdi = st->ss->container_content(st, subarray);
+			info = *mdi;
+			free(mdi);
+		}
+
+		for (sd = sra->devs; sd; sd = sd->next) {
+			int dfd;
+			char *devpath;
+
+			if ((sd->disk.state & (1 << MD_DISK_SYNC)) == 0)
+				continue;
+
+			devpath = map_dev(sd->disk.major, sd->disk.minor, 0);
+			dfd = dev_open(devpath, O_RDWR);
+			if (dfd < 0) {
+				pr_err("Failed to open %s\n", devpath);
+				ret = 1;
+				goto free_info;
+			}
+
+			if (!subarray) {
+				ret = st->ss->load_super(st, dfd, NULL);
+				if (ret) {
+					pr_err("Failed to load super-block.\n");
+					close(dfd);
+					goto free_info;
+				}
+
+				ret = st->ss->update_super(st, sra, "ppl", devname,
+							   c->verbose, 0, NULL);
+				if (ret) {
+					close(dfd);
+					st->ss->free_super(st);
+					goto free_info;
+				}
+				st->ss->getinfo_super(st, &info, NULL);
+			}
+
+			ret |= sysfs_set_num(sra, sd, "ppl_sector", info.ppl_sector);
+			ret |= sysfs_set_num(sra, sd, "ppl_size", info.ppl_size);
+
+			if (ret) {
+				pr_err("Failed to set PPL attributes for %s\n",
+				       sd->sys_name);
+				close(dfd);
+				st->ss->free_super(st);
+				goto free_info;
+			}
+
+			ret = st->ss->write_init_ppl(st, &info, dfd);
+			if (ret)
+				pr_err("Failed to write PPL\n");
+
+			close(dfd);
+
+			if (!subarray)
+				st->ss->free_super(st);
+
+			if (ret)
+				goto free_info;
+		}
+	}
+
+	ret = sysfs_set_str(sra, NULL, "consistency_policy",
+			    map_num(consistency_policies,
+				    s->consistency_policy));
+	if (ret)
+		pr_err("Failed to change array consistency policy\n");
+
+free_info:
+	sysfs_free(sra);
+free_st:
+	free(st);
+	free(subarray);
+
+	return ret;
+}
+
 /*
  * When reshaping an array we might need to backup some data.
  * This is written to all spares with a 'super_block' describing it.