block: Change direct_access calling convention

In order to support accesses to larger chunks of memory, pass in a
'size' parameter (counted in bytes), and return the amount available at
that address.

Add a new helper function, bdev_direct_access(), to handle common
functionality including partition handling, checking the length requested
is positive, checking for the sector being page-aligned, and checking
the length of the request does not pass the end of the partition.

Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Boaz Harrosh <boaz@plexistor.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Matthew Wilcox
2015-01-07 18:05:34 +02:00
committed by Jens Axboe
parent c761d96b07
commit dd22f551ac
7 changed files with 86 additions and 58 deletions

View File

@@ -139,26 +139,17 @@ axon_ram_make_request(struct request_queue *queue, struct bio *bio)
* axon_ram_direct_access - direct_access() method for block device
* @device, @sector, @data: see block_device_operations method
*/
static int
static long
axon_ram_direct_access(struct block_device *device, sector_t sector,
void **kaddr, unsigned long *pfn)
void **kaddr, unsigned long *pfn, long size)
{
struct axon_ram_bank *bank = device->bd_disk->private_data;
loff_t offset;
offset = sector;
if (device->bd_part != NULL)
offset += device->bd_part->start_sect;
offset <<= AXON_RAM_SECTOR_SHIFT;
if (offset >= bank->size) {
dev_err(&bank->device->dev, "Access outside of address space\n");
return -ERANGE;
}
loff_t offset = (loff_t)sector << AXON_RAM_SECTOR_SHIFT;
*kaddr = (void *)(bank->ph_addr + offset);
*pfn = virt_to_phys(kaddr) >> PAGE_SHIFT;
return 0;
return bank->size - offset;
}
static const struct block_device_operations axon_ram_devops = {