1 files changed, 61 insertions, 23 deletions

diff --git a/fs/partitions/check.c b/fs/partitions/check.c
index e238ab23a9e7..5dcd4b0c5533 100644
--- a/fs/partitions/check.c
+++ b/fs/partitions/check.c
@@ -45,7 +45,7 @@ extern void md_autodetect_dev(dev_t dev);
 
 int warn_no_part = 1; /*This is ugly: should make genhd removable media aware*/
 
-static int (*check_part[])(struct parsed_partitions *, struct block_device *) = {
+static int (*check_part[])(struct parsed_partitions *) = {
 	/*
 	 * Probe partition formats with tables at disk address 0
 	 * that also have an ADFS boot block at 0xdc0.
@@ -161,10 +161,11 @@ 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;
 
+	state->bdev = bdev;
 	disk_name(hd, 0, state->name);
 	printk(KERN_INFO " %s:", state->name);
 	if (isdigit(state->name[strlen(state->name)-1]))
@@ -174,7 +175,7 @@ check_partition(struct gendisk *hd, struct block_device *bdev)
 	i = res = err = 0;
 	while (!res && check_part[i]) {
 		memset(&state->parts, 0, sizeof(state->parts));
-		res = check_part[i++](state, bdev);
+		res = check_part[i++](state);
 		if (res < 0) {
 			/* We have hit an I/O error which we don't report now.
 		 	* But record it, and let the others do their job.
@@ -186,6 +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;
@@ -538,12 +541,33 @@ exit:
 	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;
@@ -562,8 +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);
@@ -581,7 +629,7 @@ int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
 	/* add partitions */
 	for (p = 1; p < state->limit; p++) {
 		sector_t size, from;
-try_scan:
+
 		size = state->parts[p].size;
 		if (!size)
 			continue;
@@ -589,30 +637,21 @@ try_scan:
 		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;
-			unsigned long long capacity;
-
 			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->set_capacity &&
-			    (disk->flags & GENHD_FL_NATIVE_CAPACITY) == 0) {
-				printk(KERN_CONT "enabling native capacity\n");
-				capacity = bdops->set_capacity(disk, ~0ULL);
-				disk->flags |= GENHD_FL_NATIVE_CAPACITY;
-				if (capacity > get_capacity(disk)) {
-					set_capacity(disk, capacity);
-					check_disk_size_change(disk, bdev);
-					bdev->bd_invalidated = 0;
-				}
-				goto try_scan;
+			if (disk_unlock_native_capacity(disk)) {
+				/* free state and restart */
+				goto rescan;
 			} else {
 				/*
 				 * we can not ignore partitions of broken tables
@@ -620,7 +659,6 @@ try_scan:
 				 * 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;
 			}
 		}