linux/block/ioctl.c, branch v4.0

block: Add discard flag to blkdev_issue_zeroout() function

2015-01-21T17:41:46Z

blkdev_issue_discard() will zero a given block range. This is done by way of explicit writing, thus provisioning or allocating the blocks on disk. There are use cases where the desired behavior is to zero the blocks but unprovision them if possible. The blocks must deterministically contain zeroes when they are subsequently read back. This patch adds a flag to blkdev_issue_zeroout() that provides this variant. If the discard flag is set and a block device guarantees discard_zeroes_data we will use REQ_DISCARD to clear the block range. If the device does not support discard_zeroes_data or if the discard request fails we will fall back to first REQ_WRITE_SAME and then a regular REQ_WRITE. Also update the callers of blkdev_issue_zero() to reflect the new flag and make sb_issue_zeroout() prefer the discard approach. Signed-off-by: Martin K. Petersen Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe

block, bdi: an active gendisk always has a request_queue associated with it

2014-09-08T16:00:35Z

bdev_get_queue() returns the request_queue associated with the specified block_device. blk_get_backing_dev_info() makes use of bdev_get_queue() to determine the associated bdi given a block_device. All the callers of bdev_get_queue() including blk_get_backing_dev_info() assume that bdev_get_queue() may return NULL and implement NULL handling; however, bdev_get_queue() requires the passed in block_device is opened and attached to its gendisk. Because an active gendisk always has a valid request_queue associated with it, bdev_get_queue() can never return NULL and neither can blk_get_backing_dev_info(). Make it clear that neither of the two functions can return NULL and remove NULL handling from all the callers. Signed-off-by: Tejun Heo Cc: Chris Mason Cc: Dave Chinner Signed-off-by: Jens Axboe

block: fix BLKSECTGET ioctl when max_sectors is greater than USHRT_MAX

2014-07-01T16:43:07Z

BLKSECTGET ioctl loads the request queue's max_sectors as unsigned short value to the argument pointer. So if the max_sector is greater than USHRT_MAX, the upper 16 bits of that is just discarded. In such case, USHRT_MAX is more preferable than the lower 16 bits of max_sectors. Signed-off-by: Akinobu Mita Cc: Jens Axboe Cc: "James E.J. Bottomley" Cc: Douglas Gilbert Cc: linux-scsi@vger.kernel.org Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe

block: replace IS_ERR and PTR_ERR with PTR_ERR_OR_ZERO

2013-11-08T16:05:31Z

This patch fixes coccinelle error regarding usage of IS_ERR and PTR_ERR instead of PTR_ERR_OR_ZERO. Signed-off-by: Duan Jiong Signed-off-by: Jens Axboe

Merge branch 'for-3.7/core' of git://git.kernel.dk/linux-block

2012-10-11T00:04:23Z

Pull block IO update from Jens Axboe: "Core block IO bits for 3.7. Not a huge round this time, it contains: - First series from Kent cleaning up and generalizing bio allocation and freeing. - WRITE_SAME support from Martin. - Mikulas patches to prevent O_DIRECT crashes when someone changes the block size of a device. - Make bio_split() work on data-less bio's (like trim/discards). - A few other minor fixups." Fixed up silent semantic mis-merge as per Mikulas Patocka and Andrew Morton. It is due to the VM no longer using a prio-tree (see commit 6b2dbba8b6ac: "mm: replace vma prio_tree with an interval tree"). So make set_blocksize() use mapping_mapped() instead of open-coding the internal VM knowledge that has changed. * 'for-3.7/core' of git://git.kernel.dk/linux-block: (26 commits) block: makes bio_split support bio without data scatterlist: refactor the sg_nents scatterlist: add sg_nents fs: fix include/percpu-rwsem.h export error percpu-rw-semaphore: fix documentation typos fs/block_dev.c:1644:5: sparse: symbol 'blkdev_mmap' was not declared blockdev: turn a rw semaphore into a percpu rw semaphore Fix a crash when block device is read and block size is changed at the same time block: fix request_queue->flags initialization block: lift the initial queue bypass mode on blk_register_queue() instead of blk_init_allocated_queue() block: ioctl to zero block ranges block: Make blkdev_issue_zeroout use WRITE SAME block: Implement support for WRITE SAME block: Consolidate command flag and queue limit checks for merges block: Clean up special command handling logic block/blk-tag.c: Remove useless kfree block: remove the duplicated setting for congestion_threshold block: reject invalid queue attribute values block: Add bio_clone_bioset(), bio_clone_kmalloc() block: Consolidate bio_alloc_bioset(), bio_kmalloc() ...

block: ioctl to zero block ranges

2012-09-20T12:31:53Z

Introduce a BLKZEROOUT ioctl which can be used to clear block ranges by way of blkdev_issue_zeroout(). Signed-off-by: Martin K. Petersen Acked-by: Mike Snitzer Signed-off-by: Jens Axboe

blk: add an upper sanity check on partition adding

2012-09-18T09:56:29Z

65536 should be ludicrous anyway but without it we overflow the memory computation doing the allocation and badness occurs. Signed-off-by: Alan Cox Signed-off-by: Jens Axboe

block: add partition resize function to blkpg ioctl

2012-08-01T10:24:18Z

Add a new operation code (BLKPG_RESIZE_PARTITION) to the BLKPG ioctl that allows altering the size of an existing partition, even if it is currently in use. This patch converts hd_struct->nr_sects into sequence counter because One might extend a partition while IO is happening to it and update of nr_sects can be non-atomic on 32bit machines with 64bit sector_t. This can lead to issues like reading inconsistent size of a partition. Sequence counter have been used so that readers don't have to take bdev mutex lock as we call sector_in_part() very frequently. Now all the access to hd_struct->nr_sects should happen using sequence counter read/update helper functions part_nr_sects_read/part_nr_sects_write. There is one exception though, set_capacity()/get_capacity(). I think theoritically race should exist there too but this patch does not modify set_capacity()/get_capacity() due to sheer number of call sites and I am afraid that change might break something. I have left that as a TODO item. We can handle it later if need be. This patch does not introduce any new races as such w.r.t set_capacity()/get_capacity(). v2: Add CONFIG_LBDAF test to UP preempt case as suggested by Phillip. Signed-off-by: Vivek Goyal Signed-off-by: Phillip Susi Signed-off-by: Jens Axboe

Merge branch 'for-3.3/core' of git://git.kernel.dk/linux-block

2012-01-15T20:24:45Z

* 'for-3.3/core' of git://git.kernel.dk/linux-block: (37 commits) Revert "block: recursive merge requests" block: Stop using macro stubs for the bio data integrity calls blockdev: convert some macros to static inlines fs: remove unneeded plug in mpage_readpages() block: Add BLKROTATIONAL ioctl block: Introduce blk_set_stacking_limits function block: remove WARN_ON_ONCE() in exit_io_context() block: an exiting task should be allowed to create io_context block: ioc_cgroup_changed() needs to be exported block: recursive merge requests block, cfq: fix empty queue crash caused by request merge block, cfq: move icq creation and rq->elv.icq association to block core block, cfq: restructure io_cq creation path for io_context interface cleanup block, cfq: move io_cq exit/release to blk-ioc.c block, cfq: move icq cache management to block core block, cfq: move io_cq lookup to blk-ioc.c block, cfq: move cfqd->icq_list to request_queue and add request->elv.icq block, cfq: reorganize cfq_io_context into generic and cfq specific parts block: remove elevator_queue->ops block: reorder elevator switch sequence ... Fix up conflicts in: - block/blk-cgroup.c Switch from can_attach_task to can_attach - block/cfq-iosched.c conflict with now removed cic index changes (we now use q->id instead)

block: Add BLKROTATIONAL ioctl

2012-01-11T15:29:31Z

Introduce an ioctl which permits applications to query whether a block device is rotational. Signed-off-by: Martin K. Petersen Signed-off-by: Jens Axboe