If the caller passes a valid kmap_op to m2p_add_override, we use kmap_op->dev_bus_addr to store the original mfn, but dev_bus_addr is part of the interface with Xen and if we are batching the hypercalls it might not have been written by the hypervisor yet. That means that later on Xen will write to it and we'll think that the original mfn is actually what Xen has written to it. Rather than "stealing" struct members from kmap_op, keep using page->index to store the original mfn and add another parameter to m2p_remove_override to get the corresponding kmap_op instead. It is now responsibility of the caller to keep track of which kmap_op corresponds to a particular page in the m2p_override (gntdev, the only user of this interface that passes a valid kmap_op, is already doing that). CC: stable@kernel.org Reported-and-Tested-By: Sander Eikelenboom <linux@eikelenboom.it> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
We weren't copying the id field so when we sent the response back to the frontend (especially with a 64-bit host and 32-bit guest), we ended up using a random value. This lead to the frontend crashing as it would try to pass to __blk_end_request_all a NULL 'struct request' (b/c it would use the 'id' to find the proper 'struct request' in its shadow array) and end up crashing: BUG: unable to handle kernel NULL pointer dereference at 000000e4 IP: [<c0646d4c>] __blk_end_request_all+0xc/0x40 .. snip.. EIP is at __blk_end_request_all+0xc/0x40 .. snip.. [<ed95db72>] blkif_interrupt+0x172/0x330 [xen_blkfront] This fixes the bug by passing in the proper id for the response. Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=824641 CC: stable@kernel.org Tested-by: William Dauchy <wdauchy@gmail.com> Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
drivers/block/xen-blkback/xenbus.c: In function 'xen_blkbk_discard': drivers/block/xen-blkback/xenbus.c:419:4: warning: passing argument 1 of 'dev_warn' makes pointer from integer without a cast +[enabled by default] include/linux/device.h:894:5: note: expected 'const struct device *' but argument is of type 'long int' It is unclear how that mistake made it in. It surely is wrong. Acked-by: Jens Axboe <axboe@kernel.dk> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
They were using the xenbus_dev_fatal() function which would change the state of the connection immediately. Which is not what we want when we advertise optional features. So make 'feature-discard','feature-barrier','feature-flush-cache' optional. Suggested-by: Jan Beulich <JBeulich@suse.com> [v1: Made the discard function void and static] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
The only reason for the distinction was for the special case of 'file' (which is assumed to be loopback device), was to reach inside the loopback device, find the underlaying file, and call fallocate on it. Fortunately "xen-blkback: convert hole punching to discard request on loop devices" removes that use-case and we now based the discard support based on blk_queue_discard(q) and extract all appropriate parameters from the 'struct request_queue'. CC: Li Dongyang <lidongyang@novell.com> Acked-by: Jan Beulich <JBeulich@suse.com> [v1: Dropping pointless initializer and keeping blank line] [v2: Remove the kfree as it is not used anymore] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* 'for-3.3/drivers' of git://git.kernel.dk/linux-block: mtip32xx: do rebuild monitoring asynchronously xen-blkfront: Use kcalloc instead of kzalloc to allocate array mtip32xx: uninitialized variable in mtip_quiesce_io() mtip32xx: updates based on feedback xen-blkback: convert hole punching to discard request on loop devices xen/blkback: Move processing of BLKIF_OP_DISCARD from dispatch_rw_block_io xen/blk[front|back]: Enhance discard support with secure erasing support. xen/blk[front|back]: Squash blkif_request_rw and blkif_request_discard together mtip32xx: update to new ->make_request() API mtip32xx: add module.h include to avoid conflict with moduleh tree mtip32xx: mark a few more items static mtip32xx: ensure that all local functions are static mtip32xx: cleanup compat ioctl handling mtip32xx: fix warnings/errors on 32-bit compiles block: Add driver for Micron RealSSD pcie flash cards
* 'stable/for-linus-3.3' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: (37 commits) xen/pciback: Expand the warning message to include domain id. xen/pciback: Fix "device has been assigned to X domain!" warning xen/pciback: Move the PCI_DEV_FLAGS_ASSIGNED ops to the "[un|]bind" xen/xenbus: don't reimplement kvasprintf via a fixed size buffer xenbus: maximum buffer size is XENSTORE_PAYLOAD_MAX xen/xenbus: Reject replies with payload > XENSTORE_PAYLOAD_MAX. Xen: consolidate and simplify struct xenbus_driver instantiation xen-gntalloc: introduce missing kfree xen/xenbus: Fix compile error - missing header for xen_initial_domain() xen/netback: Enable netback on HVM guests xen/grant-table: Support mappings required by blkback xenbus: Use grant-table wrapper functions xenbus: Support HVM backends xen/xenbus-frontend: Fix compile error with randconfig xen/xenbus-frontend: Make error message more clear xen/privcmd: Remove unused support for arch specific privcmp mmap xen: Add xenbus_backend device xen: Add xenbus device driver xen: Add privcmd device driver xen/gntalloc: fix reference counts on multi-page mappings ...