From 18eee5d03f01946724d70a8dfa8506cd279fe07b Mon Sep 17 00:00:00 2001
From: Brian Behlendorf <behlendorf1@llnl.gov>
Date: Wed, 14 Oct 2009 16:02:51 -0700
Subject: [PATCH] Fix sector size and capacity calculation.
Remove the hard coded 512 byte SECTOR_SIZE and replace it with
bdev_hardsect_size() to get the correct hardware sector size.
Usage of get_capacity() was incorrect. We the block_device
references a partition we need to return bdev->part->nr_sects.
If get_capacity() is used the entire device size will be returned
ignoring partition information. This is however the correct thing
to do when the block device in question has not partition table.
---
module/zfs/vdev_disk.c | 27 ++++++++++++++++++---------
1 file changed, 18 insertions(+), 9 deletions(-)
diff --git a/module/zfs/vdev_disk.c b/module/zfs/vdev_disk.c
index 40b7530261..62ea804101 100644
--- a/module/zfs/vdev_disk.c
+++ b/module/zfs/vdev_disk.c
@@ -76,6 +76,19 @@ vdev_bdev_mode(int smode)
}
#endif /* HAVE_OPEN_BDEV_EXCLUSIVE */
+static uint64_t
+bdev_capacity(struct block_device *bdev)
+{
+ struct hd_struct *part = bdev->bd_part;
+
+ /* The partition capacity referenced by the block device */
+ if (part)
+ return part->nr_sects;
+
+ /* Otherwise assume the full device capacity */
+ return get_capacity(bdev->bd_disk);
+}
+
static int
vdev_disk_open(vdev_t *v, uint64_t *psize, uint64_t *ashift)
{
@@ -122,15 +135,11 @@ vdev_disk_open(vdev_t *v, uint64_t *psize, uint64_t *ashift)
/* Clear the nowritecache bit, causes vdev_reopen() to try again. */
v->vdev_nowritecache = B_FALSE;
- /* Determine the actual size of the device (in bytes)
- *
- * XXX: SECTOR_SIZE is defined to 512b which may not be true for
- * your device, we must use the actual hardware sector size.
- */
- *psize = get_capacity(bdev->bd_disk) * SECTOR_SIZE;
+ /* Physical volume size in bytes */
+ *psize = bdev_capacity(bdev) * bdev_hardsect_size(bdev);
/* Based on the minimum sector size set the block size */
- *ashift = highbit(MAX(SECTOR_SIZE, SPA_MINBLOCKSIZE)) - 1;
+ *ashift = highbit(MAX(bdev_hardsect_size(bdev), SPA_MINBLOCKSIZE)) - 1;
return 0;
}
@@ -314,7 +323,7 @@ __vdev_disk_physio(struct block_device *bdev, zio_t *zio, caddr_t kbuf_ptr,
uint64_t bio_offset;
int i, error = 0, bio_count, bio_size;
- ASSERT3S(kbuf_offset % SECTOR_SIZE, ==, 0);
+ ASSERT3S(kbuf_offset % bdev_hardsect_size(bdev), ==, 0);
q = bdev_get_queue(bdev);
if (!q)
return ENXIO;
@@ -558,7 +567,7 @@ vdev_disk_read_rootlabel(char *devpath, char *devid, nvlist_t **config)
if (IS_ERR(bdev))
return -PTR_ERR(bdev);
- s = get_capacity(bdev->bd_disk) * SECTOR_SIZE;
+ s = bdev_capacity(bdev) * bdev_hardsect_size(bdev);
if (s == 0) {
vdev_bdev_close(bdev, vdev_bdev_mode(FREAD));
return EIO;