1 files changed, 306 insertions, 0 deletions
diff --git a/lib/device/online.c b/lib/device/online.c
new file mode 100644
index 000000000..9e459f935
--- /dev/null
+++ b/lib/device/online.c
@@ -0,0 +1,306 @@
+/*
+ * Copyright (C) 2021 Red Hat, Inc. All rights reserved.
+ *
+ * This file is part of LVM2.
+ *
+ * This copyrighted material is made available to anyone wishing to use,
+ * modify, copy, or redistribute it subject to the terms and conditions
+ * of the GNU Lesser General Public License v.2.1.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "base/memory/zalloc.h"
+#include "lib/misc/lib.h"
+#include "lib/commands/toolcontext.h"
+#include "lib/device/device.h"
+#include "lib/device/device_id.h"
+#include "lib/device/online.h"
+
+#include <dirent.h>
+
+static char *_vgname_in_pvid_file_buf(char *buf)
+{
+	char *p, *n;
+
+	/*
+	 * file contains:
+	 * <major>:<minor>\n
+	 * vg:<vgname>\n\0
+	 */
+
+	if (!(p = strchr(buf, '\n')))
+		return NULL;
+
+	p++; /* skip \n */
+
+	if (*p && !strncmp(p, "vg:", 3)) {
+		if ((n = strchr(p, '\n')))
+			*n = '\0';
+		return p + 3;
+	}
+	return NULL;
+}
+
+#define MAX_PVID_FILE_SIZE 512
+
+int online_pvid_file_read(char *path, int *major, int *minor, char *vgname)
+{
+	char buf[MAX_PVID_FILE_SIZE] = { 0 };
+	char *name;
+	int fd, rv;
+
+	fd = open(path, O_RDONLY);
+	if (fd < 0) {
+		log_warn("Failed to open %s", path);
+		return 0;
+	}
+
+	rv = read(fd, buf, sizeof(buf) - 1);
+	if (close(fd))
+		log_sys_debug("close", path);
+	if (!rv || rv < 0) {
+		log_warn("No info in %s", path);
+		return 0;
+	}
+	buf[rv] = 0; /* \0 terminated buffer */
+
+	if (sscanf(buf, "%d:%d", major, minor) != 2) {
+		log_warn("No device numbers in %s", path);
+		return 0;
+	}
+
+	/* vgname points to an offset in buf */
+	if ((name = _vgname_in_pvid_file_buf(buf)))
+		strncpy(vgname, name, NAME_LEN);
+	else
+		log_debug("No vgname in %s", path);
+
+	return 1;
+}
+
+/*
+ * When a PV goes offline, remove the vg online file for that VG
+ * (even if other PVs for the VG are still online).  This means
+ * that the vg will be activated again when it becomes complete.
+ */
+
+void online_vg_file_remove(const char *vgname)
+{
+	char path[PATH_MAX];
+
+	if (dm_snprintf(path, sizeof(path), "%s/%s", VGS_ONLINE_DIR, vgname) < 0) {
+		log_error("Path %s/%s is too long.", VGS_ONLINE_DIR, vgname);
+		return;
+	}
+
+	log_debug("Unlink vg online: %s", path);
+
+	if (unlink(path) && (errno != ENOENT))
+		log_sys_debug("unlink", path);
+}
+
+int online_vg_file_create(struct cmd_context *cmd, const char *vgname)
+{
+	char path[PATH_MAX];
+	int fd;
+
+	if (dm_snprintf(path, sizeof(path), "%s/%s", VGS_ONLINE_DIR, vgname) < 0) {
+		log_error_pvscan(cmd, "Path %s/%s is too long.", VGS_ONLINE_DIR, vgname);
+		return 0;
+	}
+
+	log_debug("Create vg online: %s", path);
+
+	fd = open(path, O_CREAT | O_EXCL | O_TRUNC | O_RDWR, S_IRUSR | S_IWUSR);
+	if (fd < 0) {
+		log_debug("Failed to create %s: %d", path, errno);
+	return 0;
+	}
+
+	/* We don't care about syncing, these files are not even persistent. */
+
+	if (close(fd))
+		log_sys_debug("close", path);
+
+	return 1;
+}
+
+int online_pvid_file_create(struct cmd_context *cmd, struct device *dev, const char *vgname)
+{
+	char path[PATH_MAX];
+	char buf[MAX_PVID_FILE_SIZE] = { 0 };
+	char file_vgname[NAME_LEN];
+	int file_major = 0, file_minor = 0;
+	int major, minor;
+	int fd;
+	int rv;
+	int len;
+	int len1 = 0;
+	int len2 = 0;
+
+	major = (int)MAJOR(dev->dev);
+	minor = (int)MINOR(dev->dev);
+
+	if (dm_snprintf(path, sizeof(path), "%s/%s", PVS_ONLINE_DIR, dev->pvid) < 0) {
+		log_error_pvscan(cmd, "Path %s/%s is too long.", PVS_ONLINE_DIR, dev->pvid);
+		return 0;
+	}
+
+	if ((len1 = dm_snprintf(buf, sizeof(buf), "%d:%d\n", major, minor)) < 0) {
+		log_error_pvscan(cmd, "Cannot create online file path for %s %d:%d.", dev_name(dev), major, minor);
+		return 0;
+	}
+
+	if (vgname) {
+		if ((len2 = dm_snprintf(buf + len1, sizeof(buf) - len1, "vg:%s\n", vgname)) < 0) {
+			log_print_pvscan(cmd, "Incomplete online file for %s %d:%d vg %s.", dev_name(dev), major, minor, vgname);
+			/* can still continue without vgname */
+			len2 = 0;
+		}
+	}
+
+	len = len1 + len2;
+
+	log_debug("Create pv online: %s %d:%d %s", path, major, minor, dev_name(dev));
+
+	fd = open(path, O_CREAT | O_EXCL | O_RDWR, S_IRUSR | S_IWUSR);
+	if (fd < 0) {
+		if (errno == EEXIST)
+			goto check_duplicate;
+		log_error_pvscan(cmd, "Failed to create online file for %s path %s error %d", dev_name(dev), path, errno);
+		return 0;
+	}
+
+	while (len > 0) {
+		rv = write(fd, buf, len);
+		if (rv < 0) {
+			/* file exists so it still works in part */
+			log_warn("Cannot write online file for %s to %s error %d",
+				  dev_name(dev), path, errno);
+			if (close(fd))
+				log_sys_debug("close", path);
+			return 1;
+		}
+		len -= rv;
+	}
+
+	/* We don't care about syncing, these files are not even persistent. */
+
+	if (close(fd))
+		log_sys_debug("close", path);
+
+	return 1;
+
+check_duplicate:
+
+	/*
+	 * If a PVID online file already exists for this PVID, check if the
+	 * file contains a different device number, and if so we may have a
+	 * duplicate PV.
+	 *
+	 * FIXME: disable autoactivation of the VG somehow?
+	 * The VG may or may not already be activated when a dupicate appears.
+	 * Perhaps write a new field in the pv online or vg online file?
+	 */
+
+	memset(file_vgname, 0, sizeof(file_vgname));
+
+	online_pvid_file_read(path, &file_major, &file_minor, file_vgname);
+
+	if ((file_major == major) && (file_minor == minor)) {
+		log_debug("Existing online file for %d:%d", major, minor);
+		return 1;
+	}
+
+	/* Don't know how vgname might not match, but it's not good so fail. */
+
+	if ((file_major != major) || (file_minor != minor))
+		log_error_pvscan(cmd, "PV %s is duplicate for PVID %s on %d:%d and %d:%d.",
+			         dev_name(dev), dev->pvid, major, minor, file_major, file_minor);
+
+	if (file_vgname[0] && vgname && strcmp(file_vgname, vgname))
+		log_error_pvscan(cmd, "PV %s has unexpected VG %s vs %s.",
+			         dev_name(dev), vgname, file_vgname);
+
+	return 0;
+}
+
+int online_pvid_file_exists(const char *pvid)
+{
+	char path[PATH_MAX] = { 0 };
+	struct stat buf;
+	int rv;
+
+	if (dm_snprintf(path, sizeof(path), "%s/%s", PVS_ONLINE_DIR, pvid) < 0) {
+		log_debug(INTERNAL_ERROR "Path %s/%s is too long.", PVS_ONLINE_DIR, pvid);
+		return 0;
+	}
+
+	log_debug("Check pv online: %s", path);
+
+	rv = stat(path, &buf);
+	if (!rv) {
+		log_debug("Check pv online %s: yes", pvid);
+		return 1;
+	}
+	log_debug("Check pv online %s: no", pvid);
+	return 0;
+}
+
+void online_dir_setup(struct cmd_context *cmd)
+{
+	struct stat st;
+	int rv;
+
+	if (!stat(DEFAULT_RUN_DIR, &st))
+		goto do_pvs;
+
+	log_debug("Creating run_dir.");
+	dm_prepare_selinux_context(DEFAULT_RUN_DIR, S_IFDIR);
+	rv = mkdir(DEFAULT_RUN_DIR, 0755);
+	dm_prepare_selinux_context(NULL, 0);
+
+	if ((rv < 0) && stat(DEFAULT_RUN_DIR, &st))
+		log_error_pvscan(cmd, "Failed to create %s %d", DEFAULT_RUN_DIR, errno);
+
+do_pvs:
+	if (!stat(PVS_ONLINE_DIR, &st))
+		goto do_vgs;
+
+	log_debug("Creating pvs_online_dir.");
+	dm_prepare_selinux_context(PVS_ONLINE_DIR, S_IFDIR);
+	rv = mkdir(PVS_ONLINE_DIR, 0755);
+	dm_prepare_selinux_context(NULL, 0);
+
+	if ((rv < 0) && stat(PVS_ONLINE_DIR, &st))
+		log_error_pvscan(cmd, "Failed to create %s %d", PVS_ONLINE_DIR, errno);
+
+do_vgs:
+	if (!stat(VGS_ONLINE_DIR, &st))
+		goto do_lookup;
+
+	log_debug("Creating vgs_online_dir.");
+	dm_prepare_selinux_context(VGS_ONLINE_DIR, S_IFDIR);
+	rv = mkdir(VGS_ONLINE_DIR, 0755);
+	dm_prepare_selinux_context(NULL, 0);
+
+	if ((rv < 0) && stat(VGS_ONLINE_DIR, &st))
+		log_error_pvscan(cmd, "Failed to create %s %d", VGS_ONLINE_DIR, errno);
+
+do_lookup:
+	if (!stat(PVS_LOOKUP_DIR, &st))
+		return;
+
+	log_debug("Creating pvs_lookup_dir.");
+	dm_prepare_selinux_context(PVS_LOOKUP_DIR, S_IFDIR);
+	rv = mkdir(PVS_LOOKUP_DIR, 0755);
+	dm_prepare_selinux_context(NULL, 0);
+
+	if ((rv < 0) && stat(PVS_LOOKUP_DIR, &st))
+		log_error_pvscan(cmd, "Failed to create %s %d", PVS_LOOKUP_DIR, errno);
+
+
+}