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72 lines not on this page · raw message

index 9aafff5..444ed33 100644
@@ -50,6 +50,9 @@ struct lvmcache_vginfo {
 	char *vgmetadata;	/* Copy of VG metadata as format_text string */
 	struct config_tree *cft; /* Config tree created from vgmetadata */
 				/* Lifetime is directly tied to vgmetadata */
+	struct volume_group *cached_vg;
+	unsigned holders;
+	unsigned use_count;     /* Counter of vg reusage */
 	unsigned precommitted;	/* Is vgmetadata live or precommitted? */
 };
 

@@ -122,6 +125,10 @@ struct dm_list *lvmcache_get_pvids(struct cmd_context *cmd, const char *vgname,
 
 /* Returns cached volume group metadata. */
 struct volume_group *lvmcache_get_vg(const char *vgid, unsigned precommitted);
+
+/* Decrement vginfo holders in lvmcache. */
+int lvmcache_decrement_holders(struct lvmcache_vginfo *vginfo);
+
 void lvmcache_drop_metadata(const char *vgname, int drop_precommitted);
 void lvmcache_commit_metadata(const char *vgname);
 

index ee29f25..44f5fa5 100644
@@ -866,6 +866,12 @@ static struct volume_group *_vg_make_handle(struct cmd_context *cmd,
 					    struct volume_group *vg,
 					    uint32_t failure)
 {
+	/* Never return a cached VG structure for a failure */
+	if (vg && vg->vginfo && failure != SUCCESS) {
+		release_vg(vg);
+		vg = NULL;
+	}
+
 	if (!vg && !(vg = alloc_vg("vg_make_handle", cmd, NULL)))
 		return_NULL;
 

index ef88a4d..07336c5 100644
@@ -18,6 +18,7 @@
 #include "display.h"
 #include "activate.h"
 #include "toolcontext.h"
+#include "lvmcache.h"
 
 struct volume_group *alloc_vg(const char *pool_name, struct cmd_context *cmd,
 			      const char *vg_name)

@@ -49,6 +50,8 @@ struct volume_group *alloc_vg(const char *pool_name, struct cmd_context *cmd,
 	dm_list_init(&vg->tags);
 	dm_list_init(&vg->removed_pvs);
 
+	log_debug("Allocated VG %s at %p.", vg->name, vg);
+
 	return vg;
 }
 

@@ -62,6 +65,8 @@ static void _free_vg(struct volume_group *vg)
 		return;
 	}
 
+	log_debug("Freeing VG %s at %p.", vg->name, vg);
+
 	dm_pool_destroy(vg->vgmem);
 }
 

@@ -70,6 +75,10 @@ void release_vg(struct volume_group *vg)
 	if (!vg)
 		return;
 
+	/* Decrement holders and check if vg is still in use */
+	if (vg->vginfo && lvmcache_decrement_holders(vg->vginfo))
+		return;
+
 	_free_vg(vg);
 }
 

index 5248888..9c21f37 100644
@@ -41,6 +41,7 @@ struct volume_group {
 	struct cmd_context *cmd;
 	struct dm_pool *vgmem;
 	struct format_instance *fid;
+	struct lvmcache_vginfo *vginfo;
 	struct dm_list *cmd_vgs;/* List of wanted/locked and opened VGs */
 	uint32_t cmd_missing_vgs;/* Flag marks missing VG */
 	uint32_t seqno;		/* Metadata sequence number */

index 02f8ed6..8a51509 100644
@@ -614,6 +614,22 @@ void dm_pool_empty(struct dm_pool *p);
 void dm_pool_free(struct dm_pool *p, void *ptr);
 
 /*
+ * To aid debugging, a pool can be locked. Any modifications made
+ * to the content of the pool while it is locked can be detected.
+ * Default compilation is using a crc checksum to notice modifications.
+ * The pool locking is using the mprotect with the compilation flag
+ * DEBUG_ENFORCE_POOL_LOCKING to enforce the memory protection.
+ */
+/* query pool lock status */
+int dm_pool_locked(struct dm_pool *p);
+/* mark pool as locked */
+int dm_pool_lock(struct dm_pool *p, int crc)
+	__attribute__((__warn_unused_result__));
+/* mark pool as unlocked */
+int dm_pool_unlock(struct dm_pool *p, int crc)
+	__attribute__((__warn_unused_result__));
+
+/*
  * Object building routines:
  *
  * These allow you to 'grow' an object, useful for

index af1a912..7f9a0e4 100644
@@ -33,6 +33,8 @@ struct dm_pool {
 	struct dm_list list;
 	const char *name;
 	void *orig_pool;	/* to pair it with first allocation call */
+	unsigned locked;
+	long crc;
 
 	int begun;
 	struct block *object;

@@ -71,6 +73,10 @@ static void _free_blocks(struct dm_pool *p, struct block *b)
 {
 	struct block *n;
 
+	if (p->locked)
+		log_error(INTERNAL_ERROR "_free_blocks from locked pool %s",
+			  p->name);
+
 	while (b) {
 		p->stats.bytes -= b->size;
 		p->stats.blocks_allocated--;

@@ -109,6 +115,10 @@ void *dm_pool_alloc(struct dm_pool *p, size_t s)
 
 static void _append_block(struct dm_pool *p, struct block *b)
 {
+	if (p->locked)
+		log_error(INTERNAL_ERROR "_append_blocks to locked pool %s",
+			  p->name);
+
 	if (p->tail) {
 		p->tail->next = b;
 		p->tail = b;

@@ -216,6 +226,10 @@ int dm_pool_grow_object(struct dm_pool *p, const void *extra, size_t delta)
 	struct block *new;
 	size_t new_size;
 
+	if (p->locked)
+		log_error(INTERNAL_ERROR "Grow objects in locked pool %s",
+			  p->name);
+
 	if (!delta)
 		delta = strlen(extra);
 

@@ -260,3 +274,19 @@ void dm_pool_abandon_object(struct dm_pool *p)
 	p->begun = 0;
 	p->object = NULL;
 }
+
+static long _pool_crc(const struct dm_pool *p)
+{
+#ifndef DEBUG_ENFORCE_POOL_LOCKING
+#warning pool crc not implemented with pool debug
+#endif
+	return 0;
+}
+
+static int _pool_protect(struct dm_pool *p, int prot)
+{
+#ifdef DEBUG_ENFORCE_POOL_LOCKING
+#warning pool mprotect not implemented with pool debug
+#endif
+	return 1;
+}

92 lines not on this page · raw message

126 lines not on this page · raw message

index 45965cc..38d8934 100644
@@ -689,6 +689,9 @@ struct volume_group *lvmcache_get_vg(const char *vgid, unsigned precommitted)
 	vginfo->use_count = 0;
 	vg->vginfo = vginfo;
 
+	if (!dm_pool_lock(vg->vgmem, 1))
+		goto_bad;
+
 out:
 	vginfo->holders++;
 	vginfo->use_count++;

@@ -715,6 +718,11 @@ int lvmcache_decrement_holders(struct lvmcache_vginfo *vginfo)
 		log_debug("VG %s reused %d times.",
 			  vginfo->cached_vg->name, vginfo->use_count);
 
+	/* Debug perform crc check only when it's been used more then once */
+	if (!dm_pool_unlock(vginfo->cached_vg->vgmem,
+			    (vginfo->use_count > 1)))
+		stack;
+
 	vginfo->cached_vg->vginfo = NULL;
 	vginfo->cached_vg = NULL;
 

index 44f5fa5..f846f6e 100644
@@ -2107,8 +2107,17 @@ static int _lv_postorder(struct logical_volume *lv,
 			       void *data)
 {
 	int r;
+	int pool_locked = dm_pool_locked(lv->vg->vgmem);
+
+	if (pool_locked && !dm_pool_unlock(lv->vg->vgmem, 0))
+		return_0;
+
 	r = _lv_postorder_visit(lv, fn, data);
 	_lv_postorder_cleanup(lv, 0);
+
+	if (pool_locked && !dm_pool_lock(lv->vg->vgmem, 0))
+		return_0;
+
 	return r;
 }
 

@@ -2122,6 +2131,10 @@ static int _lv_postorder_vg(struct volume_group *vg,
 {
 	struct lv_list *lvl;
 	int r = 1;
+	int pool_locked = dm_pool_locked(vg->vgmem);
+
+	if (pool_locked && !dm_pool_unlock(vg->vgmem, 0))
+		return_0;
 
 	dm_list_iterate_items(lvl, &vg->lvs)
 		if (!_lv_postorder_visit(lvl->lv, fn, data)) {

@@ -2132,6 +2145,9 @@ static int _lv_postorder_vg(struct volume_group *vg,
 	dm_list_iterate_items(lvl, &vg->lvs)
 		_lv_postorder_cleanup(lvl->lv, 0);
 
+	if (pool_locked && !dm_pool_lock(vg->vgmem, 0))
+		return_0;
+
 	return r;
 }
 

index 38d8934..4a9f2cb 100644
@@ -689,7 +689,7 @@ struct volume_group *lvmcache_get_vg(const char *vgid, unsigned precommitted)
 	vginfo->use_count = 0;
 	vg->vginfo = vginfo;
 
-	if (!dm_pool_lock(vg->vgmem, 1))
+	if (!dm_pool_lock(vg->vgmem, detect_internal_vg_cache_corruption()))
 		goto_bad;
 
 out:

@@ -720,6 +720,7 @@ int lvmcache_decrement_holders(struct lvmcache_vginfo *vginfo)
 
 	/* Debug perform crc check only when it's been used more then once */
 	if (!dm_pool_unlock(vginfo->cached_vg->vgmem,
+			    detect_internal_vg_cache_corruption() &&
 			    (vginfo->use_count > 1)))
 		stack;
 

index b3d368a..3cbd29d 100644
@@ -373,6 +373,10 @@ static int _process_config(struct cmd_context *cmd)
 	/* LVM stores sizes internally in units of 512-byte sectors. */
 	init_pv_min_size((uint64_t)pv_min_kb * (1024 >> SECTOR_SHIFT));
 
+	init_detect_internal_vg_cache_corruption
+		(find_config_tree_int(cmd, "global/detect_internal_vg_cache_corruption()",
+				      DEFAULT_DETECT_INTERNAL_VG_CACHE_CORRUPTION));
+
 	return 1;
 }
 

index cfac4d5..8b8e09b 100644
@@ -103,6 +103,7 @@
 #define DEFAULT_LOGLEVEL 0
 #define DEFAULT_INDENT 1
 #define DEFAULT_ABORT_ON_INTERNAL_ERRORS 0
+#define DEFAULT_DETECT_INTERNAL_VG_CACHE_CORRUPTION 0
 #define DEFAULT_UNITS "h"
 #define DEFAULT_SUFFIX 1
 #define DEFAULT_HOSTTAGS 0

index b9ece7f..f774512 100644
@@ -46,6 +46,8 @@ static int _activation_checks = 0;
 static char _sysfs_dir_path[PATH_MAX] = "";
 static int _dev_disable_after_error_count = DEFAULT_DISABLE_AFTER_ERROR_COUNT;
 static uint64_t _pv_min_size = (DEFAULT_PV_MIN_SIZE_KB * 1024L >> SECTOR_SHIFT);
+static int _detect_internal_vg_cache_corruption =
+	DEFAULT_DETECT_INTERNAL_VG_CACHE_CORRUPTION;
 
 void init_verbose(int level)
 {

@@ -150,6 +152,11 @@ void init_pv_min_size(uint64_t sectors)
 	_pv_min_size = sectors;
 }
 
+void init_detect_internal_vg_cache_corruption(int detect)
+{
+	_detect_internal_vg_cache_corruption = detect;
+}
+
 void set_cmd_name(const char *cmd)
 {
 	strncpy(_cmd_name, cmd, sizeof(_cmd_name));

@@ -284,3 +291,8 @@ uint64_t pv_min_size(void)
 {
 	return _pv_min_size;
 }
+
+int detect_internal_vg_cache_corruption(void)
+{
+	return _detect_internal_vg_cache_corruption;
+}

index 2cdfdd1..fcba687 100644
@@ -41,6 +41,7 @@ void init_udev_checking(int checking);
 void init_dev_disable_after_error_count(int value);
 void init_pv_min_size(uint64_t sectors);
 void init_activation_checks(int checks);
+void init_detect_internal_vg_cache_corruption(int detect);
 
 void set_cmd_name(const char *cmd_name);
 void set_sysfs_dir_path(const char *path);

@@ -65,6 +66,7 @@ int udev_checking(void);
 const char *sysfs_dir_path(void);
 uint64_t pv_min_size(void);
 int activation_checks(void);
+int detect_internal_vg_cache_corruption(void);
 
 #define DMEVENTD_MONITOR_IGNORE -1
 int dmeventd_monitor_mode(void);