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| author |   Matthew Wilcox <matthew.r.wilcox@intel.com> | 2015-01-07 18:05:34 +0200 |
|---|---|---|
| committer |   Jens Axboe <axboe@fb.com> | 2015-01-13 21:58:11 -0700 |
| commit | dd22f551ac0ad366f92f601835f6623b83adc331 (patch) | |
| tree | 47f6c4f274b3b6989869734b32afdc2e5d85769d /drivers/s390/block/dcssblk.c | |
| parent | blk-mq: export blk_mq_freeze_queue() (diff) | |
| download | linux-dev-dd22f551ac0ad366f92f601835f6623b83adc331.tar.xz linux-dev-dd22f551ac0ad366f92f601835f6623b83adc331.zip | |
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>
Diffstat (limited to 'drivers/s390/block/dcssblk.c')
| -rw-r--r-- | drivers/s390/block/dcssblk.c | 21 |
1 files changed, 9 insertions, 12 deletions
diff --git a/drivers/s390/block/dcssblk.c b/drivers/s390/block/dcssblk.c index b550c8c8d010..31d6884f3351 100644 --- a/drivers/s390/block/dcssblk.c +++ b/drivers/s390/block/dcssblk.c @@ -28,8 +28,8 @@ static int dcssblk_open(struct block_device *bdev, fmode_t mode); static void dcssblk_release(struct gendisk *disk, fmode_t mode); static void dcssblk_make_request(struct request_queue *q, struct bio *bio); -static int dcssblk_direct_access(struct block_device *bdev, sector_t secnum, - void **kaddr, unsigned long *pfn); +static long dcssblk_direct_access(struct block_device *bdev, sector_t secnum, + void **kaddr, unsigned long *pfn, long size); static char dcssblk_segments[DCSSBLK_PARM_LEN] = "\0"; @@ -866,25 +866,22 @@ fail: bio_io_error(bio); } -static int +static long dcssblk_direct_access (struct block_device *bdev, sector_t secnum, - void **kaddr, unsigned long *pfn) + void **kaddr, unsigned long *pfn, long size) { struct dcssblk_dev_info *dev_info; - unsigned long pgoff; + unsigned long offset, dev_sz; dev_info = bdev->bd_disk->private_data; if (!dev_info) return -ENODEV; - if (secnum % (PAGE_SIZE/512)) - return -EINVAL; - pgoff = secnum / (PAGE_SIZE / 512); - if ((pgoff+1)*PAGE_SIZE-1 > dev_info->end - dev_info->start) - return -ERANGE; - *kaddr = (void *) (dev_info->start+pgoff*PAGE_SIZE); + dev_sz = dev_info->end - dev_info->start; + offset = secnum * 512; + *kaddr = (void *) (dev_info->start + offset); *pfn = virt_to_phys(*kaddr) >> PAGE_SHIFT; - return 0; + return dev_sz - offset; } static void |