kernel.git/block/blk-core.c, branch linux-2.6.35.y

fix crash in scsi_dispatch_cmd()

2011-08-01T20:55:00Z

[ upstream commit bfe159a51203c15d23cb3158fffdc25ec4b4dda1 ] USB surprise removal of sr is triggering an oops in scsi_dispatch_command(). What seems to be happening is that USB is hanging on to a queue reference until the last close of the upper device, so the crash is caused by surprise remove of a mounted CD followed by attempted unmount. The problem is that USB doesn't issue its final commands as part of the SCSI teardown path, but on last close when the block queue is long gone. The long term fix is probably to make sr do the teardown in the same way as sd (so remove all the lower bits on ejection, but keep the upper disk alive until last close of user space). However, the current oops can be simply fixed by not allowing any commands to be sent to a dead queue. Cc: stable@kernel.org Signed-off-by: James Bottomley Signed-off-by: Andi Kleen

block: export blk_{get,put}_queue()

2011-08-01T20:54:54Z

commit d86e0e83b32bc84600adb0b6ea1fce389b266682 upstream. We need them in SCSI to fix a bug, but currently they are not exported to modules. Export them. Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman Signed-off-by: Andi Kleen

block: Don't count_vm_events for discard bio in submit_bio.

2010-06-24T06:14:22Z

In submit_bio, we count vm events by check READ/WRITE. But actually DISCARD_NOBARRIER also has the WRITE flag set. It looks as if in blkdev_issue_discard, we also add a page as the payload and the bio_has_data check isn't enough. So add another check for discard bio. Signed-off-by: Tao Ma Signed-off-by: Jens Axboe

block: fix DISCARD_BARRIER requests

2010-06-17T08:10:53Z

Filesystems assume that DISCARD_BARRIER are full barriers, so that they don't have to track in-progress discard operation when submitting new I/O. But currently we only treat them as elevator barriers, which don't actually do the nessecary queue drains. Also remove the unlikely around both the DISCARD and BARRIER requests - the happen far too often for a static mispredict. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

block: make blk_init_free_list and elevator_init idempotent

2010-06-04T11:47:06Z

blk_init_allocated_queue_node may fail and the caller _could_ retry. Accommodate the unlikely event that blk_init_allocated_queue_node is called on an already initialized (possibly partially) request_queue. Signed-off-by: Mike Snitzer Signed-off-by: Jens Axboe

block: avoid unconditionally freeing previously allocated request_queue

2010-06-04T11:47:06Z

On blk_init_allocated_queue_node failure, only free the request_queue if it is wasn't previously allocated outside the block layer (e.g. blk_init_queue_node was blk_init_allocated_queue_node caller). This addresses an interface bug introduced by the following commit: 01effb0 block: allow initialization of previously allocated request_queue Otherwise the request_queue may be free'd out from underneath a caller that is managing the request_queue directly (e.g. caller uses blk_alloc_queue + blk_init_allocated_queue_node). Signed-off-by: Mike Snitzer Signed-off-by: Jens Axboe

block: allow initialization of previously allocated request_queue

2010-05-11T06:57:42Z

blk_init_queue() allocates the request_queue structure and then initializes it as needed (request_fn, elevator, etc). Split initialization out to blk_init_allocated_queue_node. Introduce blk_init_allocated_queue wrapper function to model existing blk_init_queue and blk_init_queue_node interfaces. Export elv_register_queue to allow a newly added elevator to be registered with sysfs. Export elv_unregister_queue for symmetry. These changes allow DM to initialize a device's request_queue with more precision. In particular, DM no longer unconditionally initializes a full request_queue (elevator et al). It only does so for a request-based DM device. Signed-off-by: Mike Snitzer Signed-off-by: Jens Axboe

blkio: Add io_merged stat

2010-04-09T06:36:07Z

This includes both the number of bios merged into requests belonging to this cgroup as well as the number of requests merged together. In the past, we've observed different merging behavior across upstream kernels, some by design some actual bugs. This stat helps a lot in debugging such problems when applications report decreased throughput with a new kernel version. This needed adding an extra elevator function to capture bios being merged as I did not want to pollute elevator code with blkiocg knowledge and hence needed the accounting invocation to come from CFQ. Signed-off-by: Divyesh Shah Signed-off-by: Jens Axboe

laptop-mode: Make flushes per-device

2010-04-06T12:25:14Z

One of the features of laptop-mode is that it forces a writeout of dirty pages if something else triggers a physical read or write from a device. The current implementation flushes pages on all devices, rather than only the one that triggered the flush. This patch alters the behaviour so that only the recently accessed block device is flushed, preventing other disks being spun up for no terribly good reason. Signed-off-by: Matthew Garrett Signed-off-by: Jens Axboe

blkio: Increment the blkio cgroup stats for real now

2010-04-02T06:44:37Z

We also add start_time_ns and io_start_time_ns fields to struct request here to record the time when a request is created and when it is dispatched to device. We use ns uints here as ms and jiffies are not very useful for non-rotational media. Signed-off-by: Divyesh Shah Signed-off-by: Jens Axboe