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dm table: ensure targets are aligned to logical_block_size

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Ensure I/O is aligned to the logical block size of target devices.

Rename check_device_area() to device_area_is_valid() for clarity and
establish the device limits including the logical block size prior to
calling it.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This commit is contained in:
Mike Snitzer
2009-06-22 10:12:30 +01:00
committed by Alasdair G Kergon
parent 60935eb21d
commit 02acc3a4fa
1 changed files with 44 additions and 14 deletions
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56
drivers/md/dm-table.c
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@@ -383,16 +383,45 @@ static void close_dev(struct dm_dev_internal *d, struct mapped_device *md)
/* /*
* If possible, this checks an area of a destination device is valid. * If possible, this checks an area of a destination device is valid.
*/ */
static int check_device_area(struct dm_dev_internal *dd, sector_t start, static int device_area_is_valid(struct dm_target *ti, struct block_device *bdev,
sector_t len) sector_t start, sector_t len)
{ {
sector_t dev_size = i_size_read(dd->dm_dev.bdev->bd_inode) >> sector_t dev_size = i_size_read(bdev->bd_inode) >> SECTOR_SHIFT;
SECTOR_SHIFT; unsigned short logical_block_size_sectors =
ti->limits.logical_block_size >> SECTOR_SHIFT;
char b[BDEVNAME_SIZE];
if (!dev_size) if (!dev_size)
return 1; return 1;
return ((start < dev_size) && (len <= (dev_size - start))); if ((start >= dev_size) || (start + len > dev_size)) {
DMWARN("%s: %s too small for target",
dm_device_name(ti->table->md), bdevname(bdev, b));
return 0;
}
if (logical_block_size_sectors <= 1)
return 1;
if (start & (logical_block_size_sectors - 1)) {
DMWARN("%s: start=%llu not aligned to h/w "
"logical block size %hu of %s",
dm_device_name(ti->table->md),
(unsigned long long)start,
ti->limits.logical_block_size, bdevname(bdev, b));
return 0;
}
if (len & (logical_block_size_sectors - 1)) {
DMWARN("%s: len=%llu not aligned to h/w "
"logical block size %hu of %s",
dm_device_name(ti->table->md),
(unsigned long long)len,
ti->limits.logical_block_size, bdevname(bdev, b));
return 0;
}
return 1;
} }
/* /*
@@ -478,14 +507,7 @@ static int __table_get_device(struct dm_table *t, struct dm_target *ti,
} }
atomic_inc(&dd->count); atomic_inc(&dd->count);
if (!check_device_area(dd, start, len)) {
DMWARN("device %s too small for target", path);
dm_put_device(ti, &dd->dm_dev);
return -EINVAL;
}
*result = &dd->dm_dev; *result = &dd->dm_dev;
return 0; return 0;
} }
@@ -554,9 +576,17 @@ int dm_get_device(struct dm_target *ti, const char *path, sector_t start,
int r = __table_get_device(ti->table, ti, path, int r = __table_get_device(ti->table, ti, path,
start, len, mode, result); start, len, mode, result);
if (!r) if (r)
return r;
dm_set_device_limits(ti, (*result)->bdev); dm_set_device_limits(ti, (*result)->bdev);
if (!device_area_is_valid(ti, (*result)->bdev, start, len)) {
dm_put_device(ti, *result);
*result = NULL;
return -EINVAL;
}
return r; return r;
} }