---

yaml
---
r: 196876
b: refs/heads/master
c: b403a98
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 1493bf217f7f59a5d9e2095a7dbcec00fb36ca8b
+refs/heads/master: b403a98e260f3a8c7c33f58a07c7ae549852170f

trunk/fs/partitions/check.c

@@ -161,7 +161,7 @@ check_partition(struct gendisk *hd, struct block_device *bdev)
 	struct parsed_partitions *state;
 	int i, res, err;
 
-	state = kmalloc(sizeof(struct parsed_partitions), GFP_KERNEL);
+	state = kzalloc(sizeof(struct parsed_partitions), GFP_KERNEL);
 	if (!state)
 		return NULL;
 
@@ -187,6 +187,8 @@ check_partition(struct gendisk *hd, struct block_device *bdev)
 	}
 	if (res > 0)
 		return state;
+	if (state->access_beyond_eod)
+		err = -ENOSPC;
 	if (err)
 	/* The partition is unrecognized. So report I/O errors if there were any */
 		res = err;
@@ -539,13 +541,34 @@ void register_disk(struct gendisk *disk)
 	disk_part_iter_exit(&piter);
 }
 
+static bool disk_unlock_native_capacity(struct gendisk *disk)
+{
+	const struct block_device_operations *bdops = disk->fops;
+
+	if (bdops->unlock_native_capacity &&
+	    !(disk->flags & GENHD_FL_NATIVE_CAPACITY)) {
+		printk(KERN_CONT "enabling native capacity\n");
+		bdops->unlock_native_capacity(disk);
+		disk->flags |= GENHD_FL_NATIVE_CAPACITY;
+		return true;
+	} else {
+		printk(KERN_CONT "truncated\n");
+		return false;
+	}
+}
+
 int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
 {
+	struct parsed_partitions *state = NULL;
 	struct disk_part_iter piter;
 	struct hd_struct *part;
-	struct parsed_partitions *state;
 	int p, highest, res;
 rescan:
+	if (state && !IS_ERR(state)) {
+		kfree(state);
+		state = NULL;
+	}
+
 	if (bdev->bd_part_count)
 		return -EBUSY;
 	res = invalidate_partition(disk, 0);
@@ -563,8 +586,32 @@ int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
 	bdev->bd_invalidated = 0;
 	if (!get_capacity(disk) || !(state = check_partition(disk, bdev)))
 		return 0;
-	if (IS_ERR(state))	/* I/O error reading the partition table */
+	if (IS_ERR(state)) {
+		/*
+		 * I/O error reading the partition table.  If any
+		 * partition code tried to read beyond EOD, retry
+		 * after unlocking native capacity.
+		 */
+		if (PTR_ERR(state) == -ENOSPC) {
+			printk(KERN_WARNING "%s: partition table beyond EOD, ",
+			       disk->disk_name);
+			if (disk_unlock_native_capacity(disk))
+				goto rescan;
+		}
 		return -EIO;
+	}
+	/*
+	 * If any partition code tried to read beyond EOD, try
+	 * unlocking native capacity even if partition table is
+	 * sucessfully read as we could be missing some partitions.
+	 */
+	if (state->access_beyond_eod) {
+		printk(KERN_WARNING
+		       "%s: partition table partially beyond EOD, ",
+		       disk->disk_name);
+		if (disk_unlock_native_capacity(disk))
+			goto rescan;
+	}
 
 	/* tell userspace that the media / partition table may have changed */
 	kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
@@ -590,25 +637,20 @@ int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
 		from = state->parts[p].from;
 		if (from >= get_capacity(disk)) {
 			printk(KERN_WARNING
-			       "%s: p%d ignored, start %llu is behind the end of the disk\n",
+			       "%s: p%d start %llu is beyond EOD, ",
 			       disk->disk_name, p, (unsigned long long) from);
+			if (disk_unlock_native_capacity(disk))
+				goto rescan;
 			continue;
 		}
 
 		if (from + size > get_capacity(disk)) {
-			const struct block_device_operations *bdops = disk->fops;
-
 			printk(KERN_WARNING
-			       "%s: p%d size %llu exceeds device capacity, ",
+			       "%s: p%d size %llu extends beyond EOD, ",
 			       disk->disk_name, p, (unsigned long long) size);
 
-			if (bdops->unlock_native_capacity &&
-			    (disk->flags & GENHD_FL_NATIVE_CAPACITY) == 0) {
-				printk(KERN_CONT "enabling native capacity\n");
-				bdops->unlock_native_capacity(disk);
-				disk->flags |= GENHD_FL_NATIVE_CAPACITY;
+			if (disk_unlock_native_capacity(disk)) {
 				/* free state and restart */
-				kfree(state);
 				goto rescan;
 			} else {
 				/*
@@ -617,7 +659,6 @@ int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
 				 * we limit them to the end of the disk to avoid
 				 * creating invalid block devices
 				 */
-				printk(KERN_CONT "limited to end of disk\n");
 				size = get_capacity(disk) - from;
 			}
 		}

trunk/fs/partitions/check.h

@@ -15,11 +15,16 @@ struct parsed_partitions {
 	} parts[DISK_MAX_PARTS];
 	int next;
 	int limit;
+	bool access_beyond_eod;
 };
 
 static inline void *read_part_sector(struct parsed_partitions *state,
 				     sector_t n, Sector *p)
 {
+	if (n >= get_capacity(state->bdev->bd_disk)) {
+		state->access_beyond_eod = true;
+		return NULL;
+	}
 	return read_dev_sector(state->bdev, n, p);
 }