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path: root/drivers/block/xen-blkfront.c
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2009-03-05Fix kernel NULL pointer dereference in xen-blkfrontKris Shannon
When booting Xen Dom0 on a pre-release 3.2.1 hypervisor the system Oopses on a "Unable to handle kernel NULL pointer dereference" in xenwatch. From the backtrace it looks like backend_changed is calling bdget_disk with a NULL pointer. Checking for NULL and returning ENODEV instead allows the kernel to boot.
2009-02-26xen/blkfront: use blk_rq_map_sg to generate ring entriesJens Axboe
On occasion, the request will apparently have more segments than we fit into the ring. Jens says: > The second problem is that the block layer then appears to create one > too many segments, but from the dump it has rq->nr_phys_segments == > BLKIF_MAX_SEGMENTS_PER_REQUEST. I suspect the latter is due to > xen-blkfront not handling the merging on its own. It should check that > the new page doesn't form part of the previous page. The > rq_for_each_segment() iterates all single bits in the request, not dma > segments. The "easiest" way to do this is to call blk_rq_map_sg() and > then iterate the mapped sg list. That will give you what you are > looking for. > Here's a test patch, compiles but otherwise untested. I spent more > time figuring out how to enable XEN than to code it up, so YMMV! > Probably the sg list wants to be put inside the ring and only > initialized on allocation, then you can get rid of the sg on stack and > sg_init_table() loop call in the function. I'll leave that, and the > testing, to you. [Moved sg array into info structure, and initialize once. -J] Signed-off-by: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2008-12-29xen-blkfront: set queue paravirt flagFernando Luis Vázquez Cao
Xen's blkfront sets noop as the default I/O scheduler at initialization time to avoid elevator overheads such as idling, but with the advent of basic disk profiling capabilities this is not necessary anymore. We should just tell the block layer that we are a paravirt front-end driver and the elevator will automatically make the necessary adjustments. Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-11-18Release old elevator on change elevatorZhaolei
We should release old elevator when change to use a new one. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-10-21[PATCH] switch xenAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-10-21[PATCH] beginning of methods conversionAl Viro
To keep the size of changesets sane we split the switch by drivers; to keep the damn thing bisectable we do the following: 1) rename the affected methods, add ones with correct prototypes, make (few) callers handle both. That's this changeset. 2) for each driver convert to new methods. *ALL* drivers are converted in this series. 3) kill the old (renamed) methods. Note that it _is_ a flagday; all in-tree drivers are converted and by the end of this series no trace of old methods remain. The only reason why we do that this way is to keep the damn thing bisectable and allow per-driver debugging if anything goes wrong. New methods: open(bdev, mode) release(disk, mode) ioctl(bdev, mode, cmd, arg) /* Called without BKL */ compat_ioctl(bdev, mode, cmd, arg) locked_ioctl(bdev, mode, cmd, arg) /* Called with BKL, legacy */ Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-10-12Merge branch 'linus' into x86/xenIngo Molnar
Conflicts: arch/x86/kernel/cpu/common.c arch/x86/kernel/process_64.c arch/x86/xen/enlighten.c
2008-10-09block: Expand Xen blkfront for > 16 xvdChris Lalancette
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: Jens Axboe <jens.axboe@oracle.com>
2008-08-20xen: clean up domain mode predicatesJeremy Fitzhardinge
There are four operating modes Xen code may find itself running in: - native - hvm domain - pv dom0 - pv domU Clean up predicates for testing for these states to make them more consistent. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Xen-devel <xen-devel@lists.xensource.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-06xen-blkfront.c: make blkif_ioctl() staticAdrian Bunk
This patch makes the needlessly global blkif_ioctl() static. Signed-off-by: Adrian Bunk <bunk@kernel.org> Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-07-03xen: Avoid allocations causing swap activity on the resume pathIan Campbell
Avoid allocations causing swap activity on the resume path by preventing the allocations from doing IO and allowing them to access the emergency pools. These paths are used when a frontend device is trying to connect to its backend driver over Xenbus. These reconnections are triggered on demand by IO, so by definition there is already IO underway, and further IO would naturally deadlock. On resume, this path is triggered when the running system tries to continue using its devices. If it cannot then the resume will fail; to try to avoid this we let it dip into the emergency pools. [ linux-2.6.18-xen changesets e8b49cfbdac, fdb998e79aba ] Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-07-03xen/blkfront: add __exit to module_exit() handlersJan Beulich
Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-07-03xen/blkfront: Make sure that the device is fully ready before allowing release.Wim Colgate
[ linux-2.6.18-xen changeset c1c57fea77e9 ] Signed-off-by: Wim Colgate <wim@xensource.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-07-03xen/blkfront: Add the CDROM_GET_CAPABILITY ioctl to blkfront.Christian Limpach
Return 0 instead of -EINVAL if the blkfront device is a cdrom, i.e. had the VDISK_CDROM attribute. This allows udev's cdrom_id to correctly detect the device as a cdrom device. [ Add blkif_ioctl, and CDROMMULTISESSION ] [ linux-2.6.18-xen changeset d2bd9af846b5 ] Signed-off-by: Christian Limpach <Christian.Limpach@xensource.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-07-03xen/blkfront: Make sure we don't use bounce buffers, we don't need them.Ian Campbell
[ linux-2.6.18-xen changeset 667228bf8fc5 ] Signed-off-by: Ian Campbell <ian.campbell@xensource.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-04-29xen: make blkif_getgeo staticHarvey Harrison
Introduced between 2.6.25-rc2 and -rc3 drivers/block/xen-blkfront.c:139:5: warning: symbol 'blkif_getgeo' was not declared. Should it be static? Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-24xen: Add compatibility aliases for frontend driversMark McLoughlin
Before getting merged, xen-blkfront was xenblk and xen-netfront was xennet. Temporarily adding compatibility module aliases eases upgrades from older versions by e.g. allowing mkinitrd to find the new version of the module. Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-24xen: Module autoprobing support for frontend driversMark McLoughlin
Add module aliases to support autoprobing modules for xen frontend devices. Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-24xen blkfront: Delay wait for block devices until after the disk is addedChristian Limpach
When the xen block frontend driver is built as a module the module load is only synchronous up to the point where the frontend and the backend become connected rather than when the disk is added. This means that there can be a race on boot between loading the module and loading the dm-* modules and doing the scan for LVM physical volumes (all in the initrd). In the failure case the disk is not present until after the scan for physical volumes is complete. Taken from: http://xenbits.xensource.com/linux-2.6.18-xen.hg?rev/11483a00c017 Signed-off-by: Christian Limpach <Christian.Limpach@xensource.com> Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-24xen/blkfront: use bdget_diskJeremy Fitzhardinge
info->dev is never initialized to anything, so bdget(info->dev) is meaningless. Get rid of info->dev, and use bdget_disk on the gendisk. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-24xen: Make xen-blkfront write its protocol ABI to xenstoreMarkus Armbruster
Frontends are expected to write their protocol ABI to xenstore. Since the protocol ABI defaults to the backend's native ABI, things work fine without that as long as the frontend's native ABI is identical to the backend's native ABI. This is not the case for xen-blkfront running 32-on-64, because its ABI differs between 32 and 64 bit, and thus needs this fix. Based on http://xenbits.xensource.com/xen-unstable.hg?rev/c545932a18f3 and http://xenbits.xensource.com/xen-unstable.hg?rev/ffe52263b430 by Gerd Hoffmann <kraxel@suse.de> Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Jeremy Fitzhardinge <Jeremy.Fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-02-21xen: Implement getgeo for Xen virtual block device.Ian Campbell
The below implements the getgeo hook for Xen block devices. Extracted from the xen-unstable tree where it has been used for ages. It is useful to have because it allows things like grub2 (used by the Debian installer images) to work in a guest domain without having to sprinkle Xen specific hacks around the place. Signed-off-by: Ian Campbell <ijc@hellion.org.uk> Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-28blk_end_request: changing xen-blkfront (take 4)Kiyoshi Ueda
This patch converts xen-blkfront to use blk_end_request interfaces. Related 'uptodate' arguments are converted to 'error'. Cc: Jeremy Fitzhardinge <jeremy@xensource.com> 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>
2007-10-10Fixup rq_for_each_segment() indentationJens Axboe
Remove one level of nesting where appropriate. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-10Introduce rq_for_each_segment replacing rq_for_each_bioNeilBrown
Every usage of rq_for_each_bio wraps a usage of bio_for_each_segment, so these can be combined into rq_for_each_segment. We define "struct req_iterator" to hold the 'bio' and 'index' that are needed for the double iteration. Signed-off-by: Neil Brown <neilb@suse.de> Various compile fixes by me... Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-07-24[BLOCK] Get rid of request_queue_t typedefJens Axboe
Some of the code has been gradually transitioned to using the proper struct request_queue, but there's lots left. So do a full sweet of the kernel and get rid of this typedef and replace its uses with the proper type. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-07-18xen: add virtual block device driver.Jeremy Fitzhardinge
The block device frontend driver allows the kernel to access block devices exported exported by a virtual machine containing a physical block device driver. Signed-off-by: Ian Pratt <ian.pratt@xensource.com> Signed-off-by: Christian Limpach <Christian.Limpach@cl.cam.ac.uk> Signed-off-by: Chris Wright <chrisw@sous-sol.org> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Greg KH <greg@kroah.com> Cc: Jens Axboe <axboe@kernel.dk>