- 09 Oct, 2008 40 commits
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Kiyoshi Ueda authored
This patch adds a queue flag to indicate the block device can be used for request stacking. Request stacking drivers need to stack their devices on top of only devices of which q->request_fn is functional. Since bio stacking drivers (e.g. md, loop) basically initialize their queue using blk_alloc_queue() and don't set q->request_fn, the check of (q->request_fn == NULL) looks enough for that purpose. However, dm will become both types of stacking driver (bio-based and request-based). And dm will always set q->request_fn even if the dm device is bio-based of which q->request_fn is not functional actually. So we need something else to distinguish the type of the device. Adding a queue flag is a solution for that. The reason why dm always sets q->request_fn is to keep the compatibility of dm user-space tools. Currently, all dm user-space tools are using bio-based dm without specifying the type of the dm device they use. To use request-based dm without changing such tools, the kernel must decide the type of the dm device automatically. The automatic type decision can't be done at the device creation time and needs to be deferred until such tools load a mapping table, since the actual type is decided by dm target type included in the mapping table. So a dm device has to be initialized using blk_init_queue() so that we can load either type of table. Then, all queue stuffs are set (e.g. q->request_fn) and we have no element to distinguish that it is bio-based or request-based, even after a table is loaded and the type of the device is decided. By the way, some stuffs of the queue (e.g. request_list, elevator) are needless when the dm device is used as bio-based. But the memory size is not so large (about 20[KB] per queue on ia64), so I hope the memory loss can be acceptable for bio-based dm users. Signed-off-by:
Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by:
Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by:
Jens Axboe <jens.axboe@oracle.com>
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Kiyoshi Ueda authored
This patch adds blk_insert_cloned_request(), a generic request submission interface for request stacking drivers. Request-based dm will use it to submit their clones to underlying devices. blk_rq_check_limits() is also added because it is possible that the lower queue has stronger limitations than the upper queue if multiple drivers are stacking at request-level. Not only for blk_insert_cloned_request()'s internal use, the function will be used by request-based dm when the queue limitation is modified (e.g. by replacing dm's table). Signed-off-by:
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Kiyoshi Ueda authored
This patch adds blk_update_request(), which updates struct request with completing its data part, but doesn't complete the struct request itself. Though it looks like end_that_request_first() of older kernels, blk_update_request() should be used only by request stacking drivers. Request-based dm will use it in bio->bi_end_io callback to update the original request when a data part of a cloned request completes. Followings are additional background information of why request-based dm needs this interface. - Request stacking drivers can't use blk_end_request() directly from the lower driver's completion context (bio->bi_end_io or rq->end_io), because some device drivers (e.g. ide) may try to complete their request with queue lock held, and it may cause deadlock. See below for detailed description of possible deadlock: <http://marc.info/?l=linux-kernel&m=120311479108569&w=2> - To solve that, request-based dm offloads the completion of cloned struct request to softirq context (i.e. using blk_complete_request() from rq->end_io). - Though it is possible to use the same solution from bio->bi_end_io, it will delay the notification of bio completion to the original submitter. Also, it will cause inefficient partial completion, because the lower driver can't perform the cloned request anymore and request-based dm needs to requeue and redispatch it to the lower driver again later. That's not good. - So request-based dm needs blk_update_request() to perform the bio completion in the lower driver's completion context, which is more efficient. Signed-off-by: -
Jens Axboe authored
When a driver calls blk_cleanup_queue(), the device should be fully idle. However, the block layer may have pending plugging timers and the IO schedulers may have pending work in the work queues. So quisce the device by waiting for the timer and flushing the work queues. Signed-off-by: -
Chris Lalancette authored
Until recently, the maximum number of xvd block devices you could attach to a Xen domU was 16. This limitation turned out to be problematic for some users, so it was expanded to handle a much larger number of disks. However, this requires a couple of changes in the way that blkfront scans for disks. This functionality is already present in the Xen linux-2.6.18-xen.hg tree; the attached patch adds this functionality to the mainline xen-blkfront implementation. I successfully tested it on a 2.6.25 tree, and build tested it on 2.6.27-rc3. Signed-off-by:
Chris Lalancette <clalance@redhat.com> Acked-by:
Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by:
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Jens Axboe authored
Don't put functions that are only used in fs/bio-integrity.c in blkdev.h, it's much cleaner to just keep it in there. Also kill completely unused bdev_get_tag_size() Signed-off-by: -
Jens Axboe authored
We cannot abort a request if we raced with the timeout handler already, or with the IO completion. So make blk_abort_request() mark the request as complete, and only continue if we succeeded. Found and suggested by Mike Anderson <andmike@linux.vnet.ibm.com> Signed-off-by: -
Jens Axboe authored
Only works for the generic request timer handling. Allows one to sporadically ignore request completions, thus exercising the timeout handling. Signed-off-by: -
Jens Axboe authored
Not all callers need (or want!) the mempool backing guarentee, it essentially means that you can only use bio_alloc() for short allocations and not for preallocating some bio's at setup or init time. So add bio_kmalloc() which does the same thing as bio_alloc(), except it just uses kmalloc() as the backing instead of the bio mempools. Signed-off-by: -
Hugh Dickins authored
Two mods to blkdev_issue_discard(), thinking ahead to its use on swap: 1. Add gfp_mask argument, so swap allocation can use it where GFP_KERNEL might deadlock but GFP_NOIO is safe. 2. Enlarge nr_sects argument from unsigned to sector_t: unsigned long is enough to cover a whole swap area, but sector_t suits any partition. Change sb_issue_discard()'s nr_blocks to sector_t too; but no need seen for a gfp_mask there, just pass GFP_KERNEL down to blkdev_issue_discard(). Signed-off-by:
Hugh Dickins <hugh@veritas.com> Signed-off-by:
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FUJITA Tomonori authored
blk_rq_unmap_user in sg_finish_rem_req can take care of all the cases. Signed-off-by:
FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by:
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FUJITA Tomonori authored
sg_read_xfer was used to copy data to user space for READ commands. blk_rq_unmap_user does the job so sg_read_xfer does nothing useful. Signed-off-by:
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FUJITA Tomonori authored
sg_write_xfer was used to copy data from user space for WRITE commands. blk_rq_map_user_iov and blk_rq_map_user do the job so sg_write_xfer does nothing useful. Signed-off-by:
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FUJITA Tomonori authored
Calling blk_rq_map_user() at a single place is better than at different two places. It makes the code more understandable. Signed-off-by:
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FUJITA Tomonori authored
__sg_start_req() was used temporarily to call blk_get_request() during converting sg to use the block layer. Now sg always calls blk_get_request() so we can move blk_get_request() to sg_start_req(). We don't need __sg_start_req anymore. Signed-off-by:
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FUJITA Tomonori authored
It's not used for anything useful after the block layer conversion. Signed-off-by:
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FUJITA Tomonori authored
sg had lots of the own functions for the direct IO but now sg uses the block layer functions for it. There are only five lines for the direct IO. SG_ALLOW_DIO_CODE define was used to compile out the direct IO code but we don't need the define. If someone wants to remove the direct IO code, he can do easily without the define. Signed-off-by:
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FUJITA Tomonori authored
old sg_rq_end_io() was used to wrap sg_cmd_done during converting sg to use the block layer (in order to cover the difference scsi_execute_async and blk_execute_rq_nowait). Now we don't need it so let's remove it. Signed-off-by:
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Mike Anderson authored
Signed-off-by:
Mike Anderson <andmike@linux.vnet.ibm.com> Signed-off-by:
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Mike Anderson authored
Signed-off-by:
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Jens Axboe authored
Right now SCSI and others do their own command timeout handling. Move those bits to the block layer. Instead of having a timer per command, we try to be a bit more clever and simply have one per-queue. This avoids the overhead of having to tear down and setup a timer for each command, so it will result in a lot less timer fiddling. Signed-off-by:
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Andrew Patterson authored
We call flush_disk() to make sure the buffer cache for the disk is flushed after a disk resize. There are two resize cases, growing and shrinking. Given that users can shrink/then grow a disk before revalidate_disk() is called, we treat the grow case identically to shrinking. We need to flush the buffer cache after an online shrink because, as James Bottomley puts it, The two use cases for shrinking I can see are 1. planned: the fs is already shrunk to within the new boundaries and all data is relocated, so invalidate is fine (any dirty buffers that might exist in the shrunk region are there only because they were relocated but not yet written to their original location). 2. unplanned: In this case, the fs is probably toast, so whether we invalidate or not isn't going to make a whole lot of difference; it's still going to try to read or write from sectors beyond the new size and get I/O errors. Immediately invalidating shrunk disks will cause errors for outstanding I/Os for reads/write beyond the new end of the disk to be generated earlier then if we waited for the normal buffer cache operation. It also removes a potential security hole where we might keep old data around from beyond the end of the shrunk disk if the disk was not invalidated. Signed-off-by:Andrew Patterson <andrew.patterson@hp.com> Signed-off-by:
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Andrew Patterson authored
We need to be able to flush the buffer cache for for more than just when a disk is changed, so we factor out common cache flush code in check_disk_change() to an internal flush_disk() routine. This routine will then be used for both disk changes and disk resizes (in a later patch). Include the disk name in the text indicating that there are busy inodes on the device and increase the KERN severity of the message. Signed-off-by:
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Andrew Patterson authored
Modify the SCSI disk driver to call the revalidate_disk() wrapper. This allows us to do some housekeeping such as accounting for a disk being resized online. The wrapper will call sd_revalidate_disk() at the appropriate time. Signed-off-by:
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Andrew Patterson authored
Check for device resize in the rescan_partitions() routine. If the device has been resized, the bdev size is set to match. The rescan_partitions() routine is called when opening the device and when calling the BLKRRPART ioctl. Signed-off-by:
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Andrew Patterson authored
The revalidate_disk routine now checks if a disk has been resized by comparing the gendisk capacity to the bdev inode size. If they are different (usually because the disk has been resized underneath the kernel) the bdev inode size is adjusted to match the capacity. Signed-off-by:
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Andrew Patterson authored
This is a wrapper for the lower-level revalidate_disk call-backs such as sd_revalidate_disk(). It allows us to perform pre and post operations when calling them. We will use this wrapper in a later patch to adjust block device sizes after an online resize (a _post_ operation). Signed-off-by:
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Tejun Heo authored
seqf can be started multiple times for a read and the header should be printed only for the initial one. Fix it. Signed-off-by:
Tejun Heo <tj@kernel.org> Signed-off-by:
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FUJITA Tomonori authored
With the older SG interface, we don't know a user-space address to trasfer data when executing a SCSI command. So we can't pass a user-space address to blk_rq_map_user. This patch fixes sg to pass a NULL user-space address to blk_rq_map_user so that it just sets up a request and bios with page frames propely without data transfer. Signed-off-by:
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FUJITA Tomonori authored
This patch changes blk_rq_map_user to accept a NULL user-space buffer with a READ command if rq_map_data is not NULL. Thus a caller can pass page frames to lk_rq_map_user to just set up a request and bios with page frames propely. bio_uncopy_user (called via blk_rq_unmap_user) doesn't copy data to user space with such request. Signed-off-by:
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Jens Axboe authored
It refers to functions that no longer exist after the IO completion changes. Signed-off-by: -
Tejun Heo authored
DEBUG_BLOCK_EXT_DEVT shuffles SCSI and IDE device numbers and root device number set using rdev become meaningless. Root devices should be explicitly specified using textual names. Warn about it if root can't be found and DEBUG_BLOCK_EXT_DEVT is enabled. Also, add warning to the help text. Signed-off-by:
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Tejun Heo authored
bdget_disk() and blk_lookup_devt() never cared whether the specified partition (or disk) is zero sized or not. I got confused while converting those not to depend on consecutive minor numbers in commit 5a6411b1178baf534aa9138052864dfa89d3eada and later when dev0 was added it broke callers which expected to get valid return for zero sized disk devices. So, they never needed nr_sects checks in the first place. Kill them. This problem was spotted and debugged by Bartlmoiej Zolnierkiewicz. Signed-off-by:
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Jens Axboe authored
It's a debug option that you would explicitly enable to test this feature, we should default it to 'n' to prevent accidental surprises for now. Signed-off-by: -
Harvey Harrison authored
Noticed by sparse: block/blk-softirq.c:156:12: warning: symbol 'blk_softirq_init' was not declared. Should it be static? block/genhd.c:583:28: warning: function 'bdget_disk' with external linkage has definition block/genhd.c:659:17: warning: incorrect type in argument 1 (different base types) block/genhd.c:659:17: expected unsigned int [unsigned] [usertype] size block/genhd.c:659:17: got restricted gfp_t block/genhd.c:659:29: warning: incorrect type in argument 2 (different base types) block/genhd.c:659:29: expected restricted gfp_t [usertype] flags block/genhd.c:659:29: got unsigned int block: kmalloc args reversed Signed-off-by:
Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by:
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FUJITA Tomonori authored
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FUJITA Tomonori authored
This adds blk_rq_aligned helper function to see if alignment and padding requirement is satisfied for DMA transfer. This also converts blk_rq_map_kern and __blk_rq_map_user to use the helper function. Signed-off-by:
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FUJITA Tomonori authored
bio_copy_kern and bio_copy_user are very similar. This converts bio_copy_kern to use bio_copy_user. Signed-off-by:
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FUJITA Tomonori authored
This patch converts the indirect IO path (including mmap IO and old struct sg_header) to use the block layer functions (blk_get_request, blk_execute_rq_nowait, blk_rq_map_user, etc) instead of scsi_execute_async(). [Jens: fixed compile error with SCSI logging enabled] Signed-off-by:
Douglas Gilbert <dougg@torque.net> Cc: Mike Christie <michaelc@cs.wisc.edu> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by:
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FUJITA Tomonori authored
This patch converts the direct IO path (SG_FLAG_DIRECT_IO) to use the block layer functions (blk_get_request, blk_execute_rq_nowait, blk_rq_map_user, etc) instead of scsi_execute_async(). Signed-off-by:
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