device-mapper patchset 2.5.54-dm-1

@@ -812,6 +812,24 @@
 		return -EINVAL;
 	}
 
+	/*
+	 * You may ask the interface to drop its reference to an
+	 * in use device.  This is no different to unlinking a
+	 * file that someone still has open.  The device will not
+	 * actually be destroyed until the last opener closes it.
+	 * The name and uuid of the device (both are interface
+	 * properties) will be available for reuse immediately.
+	 *
+	 * You don't want to drop a _suspended_ device from the
+	 * interface, since that will leave you with no way of
+	 * resuming it.
+	 */
+	if (dm_suspended(hc->md)) {
+		DMWARN("refusing to remove a suspended device.");
+		up_write(&_hash_lock);
+		return -EPERM;
+	}
+
 	__hash_remove(hc);
 	up_write(&_hash_lock);
 	return 0;

@@ -475,7 +475,7 @@
 	ci.io->md = md;
 	ci.sector = bio->bi_sector;
 	ci.sector_count = bio_sectors(bio);
-	ci.idx = 0;
+	ci.idx = bio->bi_idx;
 
 	atomic_inc(&md->pending);
 	while (ci.sector_count)

@@ -43,15 +43,16 @@
 	struct tt_internal *ti;
 
 	read_lock(&_lock);
+
 	ti = __find_target_type(name);
-	if (ti && ti->use == 0) {
-		if (try_module_get(ti->tt.module))
-			ti->use++;
-		else
+	if (ti) {
+		if ((ti->use == 0) && !try_module_get(ti->tt.module))
 			ti = NULL;
+		else
+			ti->use++;
 	}
-	read_unlock(&_lock);
 
+	read_unlock(&_lock);
 	return ti;
 }
 

@@ -19,7 +19,7 @@
 };
 
 static LIST_HEAD(_targets);
-static rwlock_t _lock = RW_LOCK_UNLOCKED;
+static DECLARE_RWSEM(_lock);
 
 #define DM_MOD_NAME_SIZE 32
 

@@ -42,7 +42,7 @@
 {
 	struct tt_internal *ti;
 
-	read_lock(&_lock);
+	down_read(&_lock);
 
 	ti = __find_target_type(name);
 	if (ti) {

@@ -52,7 +52,7 @@
 			ti->use++;
 	}
 
-	read_unlock(&_lock);
+	up_read(&_lock);
 	return ti;
 }
 

@@ -86,13 +86,13 @@
 {
 	struct tt_internal *ti = (struct tt_internal *) t;
 
-	read_lock(&_lock);
+	down_read(&_lock);
 	if (--ti->use == 0)
 		module_put(ti->tt.module);
 
 	if (ti->use < 0)
 		BUG();
-	read_unlock(&_lock);
+	up_read(&_lock);
 
 	return;
 }

@@ -117,13 +117,13 @@
 	if (!ti)
 		return -ENOMEM;
 
-	write_lock(&_lock);
+	down_write(&_lock);
 	if (__find_target_type(t->name))
 		rv = -EEXIST;
 	else
 		list_add(&ti->list, &_targets);
 
-	write_unlock(&_lock);
+	up_write(&_lock);
 	return rv;
 }
 

@@ -131,21 +131,21 @@
 {
 	struct tt_internal *ti;
 
-	write_lock(&_lock);
+	down_write(&_lock);
 	if (!(ti = __find_target_type(t->name))) {
-		write_unlock(&_lock);
+		up_write(&_lock);
 		return -EINVAL;
 	}
 
 	if (ti->use) {
-		write_unlock(&_lock);
+		up_write(&_lock);
 		return -ETXTBSY;
 	}
 
 	list_del(&ti->list);
 	kfree(ti);
 
-	write_unlock(&_lock);
+	up_write(&_lock);
 	return 0;
 }
 

@@ -250,12 +250,12 @@
 
 	/* free the targets */
 	for (i = 0; i < t->num_targets; i++) {
-		struct dm_target *tgt = &t->targets[i];
-
-		dm_put_target_type(t->targets[i].type);
+		struct dm_target *tgt = t->targets + i;
 
 		if (tgt->type->dtr)
 			tgt->type->dtr(tgt);
+
+		dm_put_target_type(tgt->type);
 	}
 
 	vfree(t->highs);

@@ -66,8 +66,6 @@
 
 	strcat(module_name, name);
 	request_module(module_name);
-
-	return;
 }
 
 struct target_type *dm_get_target_type(const char *name)

@@ -161,7 +159,6 @@
 static void io_err_dtr(struct dm_target *ti)
 {
 	/* empty */
-	return;
 }
 
 static int io_err_map(struct dm_target *ti, struct bio *bio)

@@ -578,9 +578,8 @@
 int dm_table_add_target(struct dm_table *t, const char *type,
 			sector_t start, sector_t len, char *params)
 {
-	int r, argc;
+	int r = -EINVAL, argc;
 	char *argv[32];
-	struct target_type *tt;
 	struct dm_target *tgt;
 
 	if ((r = check_space(t)))

@@ -589,14 +588,13 @@
 	tgt = t->targets + t->num_targets;
 	memset(tgt, 0, sizeof(*tgt));
 
-	tt = dm_get_target_type(type);
-	if (!tt) {
+	tgt->type = dm_get_target_type(type);
+	if (!tgt->type) {
 		tgt->error = "unknown target type";
-		return -EINVAL;
+		goto bad;
 	}
 
 	tgt->table = t;
-	tgt->type = tt;
 	tgt->begin = start;
 	tgt->len = len;
 	tgt->error = "Unknown error";

@@ -605,23 +603,19 @@
 	 * Does this target adjoin the previous one ?
 	 */
 	if (!adjoin(t, tgt)) {
-		DMERR("Gap in table");
-		dm_put_target_type(tt);
-		return -EINVAL;
+		tgt->error = "Gap in table";
+		goto bad;
 	}
 
 	r = split_args(ARRAY_SIZE(argv), &argc, argv, params);
 	if (r) {
 		tgt->error = "couldn't split parameters";
-		dm_put_target_type(tt);
-		return r;
+		goto bad;
 	}
 
-	r = tt->ctr(tgt, argc, argv);
-	if (r) {
-		dm_put_target_type(tt);
-		return r;
-	}
+	r = tgt->type->ctr(tgt, argc, argv);
+	if (r)
+		goto bad;
 
 	t->highs[t->num_targets++] = tgt->begin + tgt->len - 1;
 

@@ -629,6 +623,11 @@
 	 * the merge fn apply the target level restrictions. */
 	combine_restrictions_low(&t->limits, &tgt->limits);
 	return 0;
+
+ bad:
+	printk(KERN_ERR DM_NAME ": %s\n", tgt->error);
+	dm_put_target_type(tgt->type);
+	return r;
 }
 
 static int setup_indexes(struct dm_table *t)

@@ -163,8 +163,7 @@
 
 static int io_err_map(struct dm_target *ti, struct bio *bio)
 {
-	bio_io_error(bio, 0);
-	return 0;
+	return -EIO;
 }
 
 static struct target_type error_target = {

@@ -751,3 +751,4 @@
 EXPORT_SYMBOL(dm_get_device);
 EXPORT_SYMBOL(dm_put_device);
 EXPORT_SYMBOL(dm_table_event);
+EXPORT_SYMBOL(dm_table_get_mode);

@@ -347,18 +347,15 @@
 	struct bio_vec *bv = bio->bi_io_vec + idx;
 
 	clone = bio_alloc(GFP_NOIO, 1);
+	memcpy(clone->bi_io_vec, bv, sizeof(*bv));
 
-	if (clone) {
-		memcpy(clone->bi_io_vec, bv, sizeof(*bv));
-
-		clone->bi_sector = sector;
-		clone->bi_bdev = bio->bi_bdev;
-		clone->bi_rw = bio->bi_rw;
-		clone->bi_vcnt = 1;
-		clone->bi_size = to_bytes(len);
-		clone->bi_io_vec->bv_offset = offset;
-		clone->bi_io_vec->bv_len = clone->bi_size;
-	}
+	clone->bi_sector = sector;
+	clone->bi_bdev = bio->bi_bdev;
+	clone->bi_rw = bio->bi_rw;
+	clone->bi_vcnt = 1;
+	clone->bi_size = to_bytes(len);
+	clone->bi_io_vec->bv_offset = offset;
+	clone->bi_io_vec->bv_len = clone->bi_size;
 
 	return clone;
 }

@@ -432,11 +429,6 @@
 
 		clone = split_bvec(bio, ci->sector, ci->idx,
 				   bv->bv_offset, max);
-		if (!clone) {
-			dec_pending(ci->io, -ENOMEM);
-			return;
-		}
-
 		__map_bio(ti, clone, ci->io);
 
 		ci->sector += max;

@@ -446,11 +438,6 @@
 		len = to_sector(bv->bv_len) - max;
 		clone = split_bvec(bio, ci->sector, ci->idx,
 				   bv->bv_offset + to_bytes(max), len);
-		if (!clone) {
-			dec_pending(ci->io, -ENOMEM);
-			return;
-		}
-
 		__map_bio(ti, clone, ci->io);
 
 		ci->sector += len;