[lvm-devel] master - activation: enhance holders detection
Zdenek Kabelac
zkabelac at sourceware.org
Sat Nov 25 23:38:24 UTC 2017
Gitweb: https://sourceware.org/git/?p=lvm2.git;a=commitdiff;h=8c6fd0933fa4ee9b79ae5edbb90afe6a3d893b18
Commit: 8c6fd0933fa4ee9b79ae5edbb90afe6a3d893b18
Parent: ce83162d7c7eae008935989a26dbf23dfb08d0f9
Author: Zdenek Kabelac <zkabelac at redhat.com>
AuthorDate: Fri Nov 24 20:59:38 2017 +0100
Committer: Zdenek Kabelac <zkabelac at redhat.com>
CommitterDate: Sun Nov 26 00:31:26 2017 +0100
activation: enhance holders detection
Use code which detectes handlers in a way, which is more
backward-compatible friendly.
Replace read of 'sysfs' uuid entry with dm ioctl call.
Use /sys/block/dm-X/holders path instead of
new path /sys/dev/block/major:minor/holders.
TODO:
There are few more occurencies of this logic around the code
so some abstract interface should be considered.
---
lib/activate/dev_manager.c | 128 ++++++++++++++++++++++++--------------------
1 files changed, 69 insertions(+), 59 deletions(-)
diff --git a/lib/activate/dev_manager.c b/lib/activate/dev_manager.c
index 76fc546..429f4f6 100644
--- a/lib/activate/dev_manager.c
+++ b/lib/activate/dev_manager.c
@@ -1720,81 +1720,52 @@ static uint16_t _get_udev_flags(struct dev_manager *dm, const struct logical_vol
static int _add_lv_to_dtree(struct dev_manager *dm, struct dm_tree *dtree,
const struct logical_volume *lv, int origin_only);
-/*
- * Add exiting devices which holds given LV device open.
- * This is used in case when metadata already do not contain information
- * i.e. PVMOVE is being finished and final table is going to be resumed.
- */
-static int _add_holders_to_dtree(struct dev_manager *dm, struct dm_tree *dtree,
- const struct logical_volume *lv, struct dm_info *info)
+
+static int _check_holder(struct dev_manager *dm, struct dm_tree *dtree,
+ const struct logical_volume *lv, uint32_t major,
+ const char *d_name)
{
const char *default_uuid_prefix = dm_uuid_prefix();
const size_t default_uuid_prefix_len = strlen(default_uuid_prefix);
- const char *sysfs_dir = dm_sysfs_dir();
- char sysfs_path[PATH_MAX];
- char uuid_path[PATH_MAX];
- char uuid_buf[DM_UUID_LEN + 1];
- char *uuid;
- struct dirent *dirent;
- DIR *d;
- FILE *fp;
+ const char *name;
+ const char *uuid;
+ struct dm_info info;
+ struct dm_task *dmt;
struct logical_volume *lv_det;
- int r = 0;
+ union lvid id;
+ int dev, r = 0;
- /* Sysfs path of holders */
- if (dm_snprintf(sysfs_path, sizeof(sysfs_path), "%sdev/block/" FMTu32
- ":" FMTu32 "/holders", sysfs_dir, info->major, info->minor) < 0) {
- log_error("sysfs_path dm_snprintf failed.");
- return 0;
- }
-
- if (!(d = opendir(sysfs_path))) {
- if (errno != ENOENT)
- log_sys_error("opendir", sysfs_path);
+ errno = 0;
+ dev = strtoll(d_name + 3, NULL, 10);
+ if (errno) {
+ log_error("Failed to parse dm device minor number from %s.", d_name);
return 0;
}
- while ((dirent = readdir(d))) {
- if (!strcmp(dirent->d_name, ".") || !strcmp(dirent->d_name, ".."))
- continue;
-
- /* Determine path where sysfs holds UUID for holding dm device */
- if (dm_snprintf(uuid_path, sizeof(uuid_path), "%s/%s/dm/uuid",
- sysfs_path, dirent->d_name) < 0) {
- log_error("uuid_path dm_snprintf failed.");
- goto out;
- }
-
- if (!(fp = fopen(uuid_path, "r"))) {
- log_sys_error("fopen", uuid_path);
- goto out;
- }
-
- if (!fgets(uuid_buf, sizeof(uuid_buf), fp)) {
- log_sys_error("fgets", uuid_path);
- fclose(fp);
- goto out;
- }
+ if (!(dmt = _setup_task_run(DM_DEVICE_INFO, &info, NULL, NULL, NULL,
+ major, dev, 0, 0, 0)))
+ return_0;
- if (fclose(fp))
- log_sys_debug("fclose", uuid_path);
+ if (info.exists) {
+ uuid = dm_task_get_uuid(dmt);
+ name = dm_task_get_name(dmt);
- uuid = uuid_buf;
- log_debug_activation("Checking holder of LV %s with uuid %s.",
- display_lvname(lv), uuid);
+ log_debug_activation("Checking holder of %s %s (" FMTu32 ":" FMTu32 ") %s.",
+ display_lvname(lv), uuid, info.major, info.minor,
+ name);
- /* Skip common uuid LVM prefix */
+ /* Skip common uuid prefix */
if (!strncmp(default_uuid_prefix, uuid, default_uuid_prefix_len))
uuid += default_uuid_prefix_len;
- /* Check holder comes from processed VG and is not yet in dmtree */
if (!strncmp(uuid, (char*)&lv->vg->id, sizeof(lv->vg->id)) &&
!dm_tree_find_node_by_uuid(dtree, uuid)) {
- uuid[2 * sizeof(struct id)] = 0; /* Cut any suffix */
+ dm_strncpy((char*)&id, uuid, 2 * sizeof(struct id) + 1);
+
/* If UUID is not yet in dtree, look for matching LV */
- if (!(lv_det = find_lv_in_vg_by_lvid(lv->vg, (union lvid*)uuid))) {
- log_error("Cannot find holding uuid %s in VG %s.",
- uuid, lv->vg->name);
+ if (!(lv_det = find_lv_in_vg_by_lvid(lv->vg, &id))) {
+ log_error("Cannot find holder with device name %s in VG %s.",
+ name, lv->vg->name);
goto out;
}
@@ -1808,10 +1779,49 @@ static int _add_holders_to_dtree(struct dev_manager *dm, struct dm_tree *dtree,
}
}
+ r = 1;
+out:
+ dm_task_destroy(dmt);
+
+ return r;
+}
+
+/*
+ * Add exiting devices which holds given LV device open.
+ * This is used in case when metadata already do not contain information
+ * i.e. PVMOVE is being finished and final table is going to be resumed.
+ */
+static int _add_holders_to_dtree(struct dev_manager *dm, struct dm_tree *dtree,
+ const struct logical_volume *lv, struct dm_info *info)
+{
+ const char *sysfs_dir = dm_sysfs_dir();
+ char sysfs_path[PATH_MAX];
+ struct dirent *dirent;
+ DIR *d;
+ int r = 0;
+
+ /* Sysfs path of holders */
+ if (dm_snprintf(sysfs_path, sizeof(sysfs_path), "%sblock/dm-" FMTu32
+ "/holders", sysfs_dir, info->minor) < 0) {
+ log_error("sysfs_path dm_snprintf failed.");
+ return 0;
+ }
+
+ if (!(d = opendir(sysfs_path))) {
+ log_sys_error("opendir", sysfs_path);
+ return 0;
+ }
+
+ while ((dirent = readdir(d)))
+ /* Expects minor is added to 'dm-' prefix */
+ if (!strncmp(dirent->d_name, "dm-", 3) &&
+ !_check_holder(dm, dtree, lv, info->major, dirent->d_name))
+ goto_out;
+
r = 1;
out:
if (closedir(d))
- log_sys_error("closedir", "holders");
+ log_sys_debug("closedir", "holders");
return r;
}
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