File activate-Improve-snapshot-merge-initiation.patch of Package lvm2

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File activate-Improve-snapshot-merge-initiation.patch of Package lvm2 (Revision deb897da430dd72eb136f989efd733e5)

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From 572996ffe1aae64a622a2706e60017937e1c5120 Mon Sep 17 00:00:00 2001
From: Liuhua Wang <lwang@suse.com>
Date: Thu, 21 Apr 2016 15:45:45 +0800
Subject: [PATCH] activate: Improve snapshot merge initiation

A snapshot merge into its origin cannot be initiated while the devices
are in use.  If there is outside interference (such as from udev),
the suspend (preload) and resume stages can reach conflicting decisions
about whether or not to proceed.

Try to make the logic more robust by checking the inactive or live
table during resume.  (This is still not perfect.)

Commit: 6954de22e2281876506c0db1c98972242de977fb
References: bsc#970943
---
 lib/activate/activate.c    |  1 +
 lib/activate/activate.h    |  1 +
 lib/activate/dev_manager.c | 41 +++++++++++++++++++++++++++++++----------
 3 files changed, 33 insertions(+), 10 deletions(-)

diff --git a/lib/activate/activate.c b/lib/activate/activate.c
index 3724b52..5a81f84 100644
--- a/lib/activate/activate.c
+++ b/lib/activate/activate.c
@@ -2056,6 +2056,7 @@ static int _lv_resume(struct cmd_context *cmd, const char *lvid_s,
 	}
 
 	laopts->read_only = _passes_readonly_filter(cmd, lv);
+   laopts->resuming = 1;
 
 	if (!_lv_activate_lv(lv, laopts))
 		goto_out;
diff --git a/lib/activate/activate.h b/lib/activate/activate.h
index 01d6444..9ab55d8 100644
--- a/lib/activate/activate.h
+++ b/lib/activate/activate.h
@@ -81,6 +81,7 @@ struct lv_activate_opts {
 				 * set of flags to avoid any scanning in udev. These udev
 				 * flags are persistent in udev db for any spurious event
 				 * that follows. */
+    unsigned resuming;  /* Set when resuming after a suspend. */
 };
 
 void set_activation(int activation, int silent);
diff --git a/lib/activate/dev_manager.c b/lib/activate/dev_manager.c
index 1171f4c..23b23b7 100644
--- a/lib/activate/dev_manager.c
+++ b/lib/activate/dev_manager.c
@@ -788,13 +788,28 @@ int lv_has_target_type(struct dm_pool *mem, const struct logical_volume *lv,
 	if (!dm_task_get_info(dmt, &info) || !info.exists)
 		goto_out;
 
+    /* If there is a preloaded table, use that in preference. */
+    if (info.inactive_table) {
+        dm_task_destroy(dmt);
+    
+        if (!(dmt = _setup_task(NULL, dlid, 0, DM_DEVICE_STATUS, 0, 0, 0)))
+            goto_bad;
+    
+        if (!dm_task_query_inactive_table(dmt))
+            goto_out;
+    
+        if (!dm_task_run(dmt))
+            goto_out;
+    
+        if (!dm_task_get_info(dmt, &info) || !info.exists || !info.inactive_table)
+            goto_out;
+    }
+
 	do {
 		next = dm_get_next_target(dmt, next, &start, &length,
 					  &type, &params);
-		if (type && strncmp(type, target_type,
-				    strlen(target_type)) == 0) {
-			if (info.live_table)
-				r = 1;
+        if (type && !strncmp(type, target_type, strlen(target_type))) {
+            r = 1;
 			break;
 		}
 	} while (next);
@@ -2717,6 +2732,7 @@ static int _add_new_lv_to_dtree(struct dev_manager *dm, struct dm_tree *dtree,
 	uint32_t read_ahead = lv->read_ahead;
 	uint32_t read_ahead_flags = UINT32_C(0);
 	int save_pending_delete = dm->track_pending_delete;
+    int snap_dev_is_open = 0;
 
 	/* LV with pending delete is never put new into a table */
 	if (lv_is_pending_delete(lv) && !_cached_dm_info(dm->mem, dtree, lv, NULL))
@@ -2749,12 +2765,17 @@ static int _add_new_lv_to_dtree(struct dev_manager *dm, struct dm_tree *dtree,
 		    ((dinfo = _cached_dm_info(dm->mem, dtree,
 					      seg_is_thin_volume(seg) ?
 					      seg->lv : seg->cow, NULL)) &&
-		     dinfo->open_count)) {
-			if (seg_is_thin_volume(seg) ||
-			    /* FIXME Is there anything simpler to check for instead? */
-			    !lv_has_target_type(dm->mem, lv, NULL, "snapshot-merge"))
-				laopts->no_merging = 1;
-		}
+                    dinfo->open_count))
+            snap_dev_is_open = 1;
+        
+        /* Preload considers open devices. */
+        /* Resume looks at the table that will be the live one after the operation. */
+        if ((!laopts->resuming && snap_dev_is_open && (seg_is_thin_volume(seg) ||
+            !lv_has_target_type(dm->mem, lv, NULL, "snapshot-merge"))) || 
+            (laopts->resuming && !seg_is_thin_volume(seg) && !lv_has_target_type(dm->mem, lv, NULL, "snapshot-merge"))){
+                log_debug_activation("Postponing pending snapshot merge for origin LV %s.", display_lvname(lv));
+                laopts->no_merging = 1;
+    	}
 	}
 
 	if (!(name = dm_build_dm_name(dm->mem, lv->vg->name, lv->name, layer)))
-- 
1.8.4.5

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File activate-Improve-snapshot-merge-initiation.patch of Package lvm2 (Revision deb897da430dd72eb136f989efd733e5)

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