From 02acc3a4fa0a6c2a5ccc4fb722b55fb710265882 Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Mon, 22 Jun 2009 10:12:30 +0100 Subject: dm table: ensure targets are aligned to logical_block_size 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 Signed-off-by: Alasdair G Kergon --- drivers/md/dm-table.c | 58 ++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 44 insertions(+), 14 deletions(-) (limited to 'drivers/md') diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index af1ceae2582a..535fdaf2473d 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -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. */ -static int check_device_area(struct dm_dev_internal *dd, sector_t start, - sector_t len) +static int device_area_is_valid(struct dm_target *ti, struct block_device *bdev, + sector_t start, sector_t len) { - sector_t dev_size = i_size_read(dd->dm_dev.bdev->bd_inode) >> - SECTOR_SHIFT; + sector_t dev_size = i_size_read(bdev->bd_inode) >> SECTOR_SHIFT; + unsigned short logical_block_size_sectors = + ti->limits.logical_block_size >> SECTOR_SHIFT; + char b[BDEVNAME_SIZE]; if (!dev_size) 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); - 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; - return 0; } @@ -554,8 +576,16 @@ int dm_get_device(struct dm_target *ti, const char *path, sector_t start, int r = __table_get_device(ti->table, ti, path, start, len, mode, result); - if (!r) - dm_set_device_limits(ti, (*result)->bdev); + if (r) + return r; + + 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; } -- cgit v1.2.3