aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/block/xen-blkback/blkback.c (follow)
AgeCommit message (Collapse)AuthorFilesLines
2018-08-27xen/blkback: move persistent grants flags to boolJuergen Gross1-7/+6
The struct persistent_gnt flags member is meant to be a bitfield of different flags. There is only PERSISTENT_GNT_ACTIVE flag left, so convert it to a bool named "active". Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Roger Pau Monné <roger.pau@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2018-08-27xen/blkback: don't keep persistent grants too longJuergen Gross1-40/+48
Persistent grants are allocated until a threshold per ring is being reached. Those grants won't be freed until the ring is being destroyed meaning there will be resources kept busy which might no longer be used. Instead of freeing only persistent grants until the threshold is reached add a timestamp and remove all persistent grants not having been in use for a minute. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Roger Pau Monné <roger.pau@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2018-05-24block drivers/block: Use octal not symbolic permissionsJoe Perches1-1/+1
Convert the S_<FOO> symbolic permissions to their octal equivalents as using octal and not symbolic permissions is preferred by many as more readable. see: https://lkml.org/lkml/2016/8/2/1945 Done with automated conversion via: $ ./scripts/checkpatch.pl -f --types=SYMBOLIC_PERMS --fix-inplace <files...> Miscellanea: o Wrapped modified multi-line calls to a single line where appropriate o Realign modified multi-line calls to open parenthesis Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-23block: replace bi_bdev with a gendisk pointer and partitions indexChristoph Hellwig1-2/+2
This way we don't need a block_device structure to submit I/O. The block_device has different life time rules from the gendisk and request_queue and is usually only available when the block device node is open. Other callers need to explicitly create one (e.g. the lightnvm passthrough code, or the new nvme multipathing code). For the actual I/O path all that we need is the gendisk, which exists once per block device. But given that the block layer also does partition remapping we additionally need a partition index, which is used for said remapping in generic_make_request. Note that all the block drivers generally want request_queue or sometimes the gendisk, so this removes a layer of indirection all over the stack. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-18xen-blkback: Avoid that gcc 7 warns about fall-through when building with W=1Bart Van Assche1-0/+1
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Roger Pau Monn303251 <roger.pau@citrix.com> Cc: xen-devel@lists.xenproject.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-18xen-blkback: Fix indentationBart Van Assche1-2/+2
Avoid that smatch reports the following warning when building with C=2 CHECK="smatch -p=kernel": drivers/block/xen-blkback/blkback.c:710 xen_blkbk_unmap_prepare() warn: inconsistent indenting Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Roger Pau Monn303251 <roger.pau@citrix.com> Cc: xen-devel@lists.xenproject.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-22Merge commit '8e8320c9315c' into for-4.13/blockJens Axboe1-14/+12
Pull in the fix for shared tags, as it conflicts with the pending changes in for-4.13/block. We already pulled in v4.12-rc5 to solve other conflicts or get fixes that went into 4.12, so not a lot of changes in this merge. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-13xen-blkback: don't leak stack data via response ringJan Beulich1-11/+12
Rather than constructing a local structure instance on the stack, fill the fields directly on the shared ring, just like other backends do. Build on the fact that all response structure flavors are actually identical (the old code did make this assumption too). This is XSA-216. Cc: stable@vger.kernel.org Signed-off-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2017-06-13xen/blkback: don't use xen_blkif_get() in xen-blkback kthreadJuergen Gross1-3/+0
There is no need to use xen_blkif_get()/xen_blkif_put() in the kthread of xen-blkback. Thread stopping is synchronous and using the blkif reference counting in the kthread will avoid to ever let the reference count drop to zero at the end of an I/O running concurrent to disconnecting and multiple rings. Setting ring->xenblkd to NULL after stopping the kthread isn't needed as the kthread does this already. Signed-off-by: Juergen Gross <jgross@suse.com> Tested-by: Steven Haigh <netwiz@crc.id.au> Acked-by: Roger Pau Monné <roger.pau@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2017-06-09block: switch bios to blk_status_tChristoph Hellwig1-11/+8
Replace bi_error with a new bi_status to allow for a clear conversion. Note that device mapper overloaded bi_error with a private value, which we'll have to keep arround at least for now and thus propagate to a proper blk_status_t value. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-01block,fs: use REQ_* flags directlyChristoph Hellwig1-5/+5
Remove the WRITE_* and READ_SYNC wrappers, and just use the flags directly. Where applicable this also drops usage of the bio_set_op_attrs wrapper. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07xen: use bio op accessorsMike Christie1-12/+15
Separate the op from the rq_flag_bits and have xen set/get the bio using bio_set_op_attrs/bio_op. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07block/fs/drivers: remove rw argument from submit_bioMike Christie1-1/+3
This has callers of submit_bio/submit_bio_wait set the bio->bi_rw instead of passing it in. This makes that use the same as generic_make_request and how we set the other bio fields. Signed-off-by: Mike Christie <mchristi@redhat.com> Fixed up fs/ext4/crypto.c Signed-off-by: Jens Axboe <axboe@fb.com>
2016-01-21Merge branch 'for-4.5/drivers' of git://git.kernel.dk/linux-blockLinus Torvalds1-183/+208
Pull block driver updates from Jens Axboe: "This is the block driver pull request for 4.5, with the exception of NVMe, which is in a separate branch and will be posted after this one. This pull request contains: - A set of bcache stability fixes, which have been acked by Kent. These have been used and tested for more than a year by the community, so it's about time that they got in. - A set of drbd updates from the drbd team (Andreas, Lars, Philipp) and Markus Elfring, Oleg Drokin. - A set of fixes for xen blkback/front from the usual suspects, (Bob, Konrad) as well as community based fixes from Kiri, Julien, and Peng. - A 2038 time fix for sx8 from Shraddha, with a fix from me. - A small mtip32xx cleanup from Zhu Yanjun. - A null_blk division fix from Arnd" * 'for-4.5/drivers' of git://git.kernel.dk/linux-block: (71 commits) null_blk: use sector_div instead of do_div mtip32xx: restrict variables visible in current code module xen/blkfront: Fix crash if backend doesn't follow the right states. xen/blkback: Fix two memory leaks. xen/blkback: make st_ statistics per ring xen/blkfront: Handle non-indirect grant with 64KB pages xen-blkfront: Introduce blkif_ring_get_request xen-blkback: clear PF_NOFREEZE for xen_blkif_schedule() xen/blkback: Free resources if connect_ring failed. xen/blocks: Return -EXX instead of -1 xen/blkback: make pool of persistent grants and free pages per-queue xen/blkback: get the number of hardware queues/rings from blkfront xen/blkback: pseudo support for multi hardware queues/rings xen/blkback: separate ring information out of struct xen_blkif xen/blkfront: correct setting for xen_blkif_max_ring_order xen/blkfront: make persistent grants pool per-queue xen/blkfront: Remove duplicate setting of ->xbdev. xen/blkfront: Cleanup of comments, fix unaligned variables, and syntax errors. xen/blkfront: negotiate number of queues/rings to be used with backend xen/blkfront: split per device io_lock ...
2016-01-04xen/blkback: make st_ statistics per ringBob Liu1-18/+16
Make st_* statistics per ring and the VBD sysfs would iterate over all the rings. Note: xenvbd_sysfs_delif() is called in xen_blkbk_remove() before all rings are torn down, so it's safe. Signed-off-by: Bob Liu <bob.liu@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> --- v2: Aligned the variables on the same column.
2016-01-04xen-blkback: clear PF_NOFREEZE for xen_blkif_schedule()Jiri Kosina1-0/+1
xen_blkif_schedule() kthread calls try_to_freeze() at the beginning of every attempt to purge the LRU. This operation can't ever succeed though, as the kthread hasn't marked itself as freezable. Before (hopefully eventually) kthread freezing gets converted to fileystem freezing, we'd rather mark xen_blkif_schedule() freezable (as it can generate I/O during suspend). Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2016-01-04xen/blkback: make pool of persistent grants and free pages per-queueBob Liu1-110/+92
Make pool of persistent grants and free pages per-queue/ring instead of per-device to get better scalability. Test was done based on null_blk driver: dom0: v4.2-rc8 16vcpus 10GB "modprobe null_blk" domu: v4.2-rc8 16vcpus 10GB [test] rw=read direct=1 ioengine=libaio bs=4k time_based runtime=30 filename=/dev/xvdb numjobs=16 iodepth=64 iodepth_batch=64 iodepth_batch_complete=64 group_reporting Results: iops1: After patch "xen/blkfront: make persistent grants per-queue". iops2: After this patch. Queues: 1 4 8 16 Iops orig(k): 810 1064 780 700 Iops1(k): 810 1230(~20%) 1024(~20%) 850(~20%) Iops2(k): 810 1410(~35%) 1354(~75%) 1440(~100%) With 4 queues after this commit we can get ~75% increase in IOPS, and performance won't drop if increasing queue numbers. Please find the respective chart in this link: https://www.dropbox.com/s/agrcy2pbzbsvmwv/iops.png?dl=0 Signed-off-by: Bob Liu <bob.liu@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2016-01-04xen/blkback: get the number of hardware queues/rings from blkfrontBob Liu1-0/+13
Backend advertises "multi-queue-max-queues" to front, also get the negotiated number from "multi-queue-num-queues" written by blkfront. Signed-off-by: Bob Liu <bob.liu@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2016-01-04xen/blkback: separate ring information out of struct xen_blkifBob Liu1-102/+133
Split per ring information to an new structure "xen_blkif_ring", so that one vbd device can be associated with one or more rings/hardware queues. Introduce 'pers_gnts_lock' to protect the pool of persistent grants since we may have multi backend threads. This patch is a preparation for supporting multi hardware queues/rings. Signed-off-by: Arianna Avanzini <avanzini.arianna@gmail.com> Signed-off-by: Bob Liu <bob.liu@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> --- v2: Align the variables in the structure.
2015-12-18xen-blkback: read from indirect descriptors only onceRoger Pau Monné1-5/+10
Since indirect descriptors are in memory shared with the frontend, the frontend could alter the first_sect and last_sect values after they have been validated but before they are recorded in the request. This may result in I/O requests that overflow the foreign page, possibly overwriting local pages when the I/O request is executed. When parsing indirect descriptors, only read first_sect and last_sect once. This is part of XSA155. CC: stable@vger.kernel.org Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2015-10-23xen/xenbus: Rename *RING_PAGE* to *RING_GRANT*Julien Grall1-4/+4
Linux may use a different page size than the size of grant. So make clear that the order is actually in number of grant. Signed-off-by: Julien Grall <julien.grall@citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-10-23block/xen-blkback: Make it running on 64KB page granularityJulien Grall1-2/+3
The PV block protocol is using 4KB page granularity. The goal of this patch is to allow a Linux using 64KB page granularity behaving as a block backend on a non-modified Xen. It's only necessary to adapt the ring size and the number of request per indirect frames. The rest of the code is relying on the grant table code. Note that the grant table code is allocating a Linux page per grant which will result to waste 6OKB for every grant when Linux is using 64KB page granularity. This could be improved by sharing the page between multiple grants. Signed-off-by: Julien Grall <julien.grall@citrix.com> Acked-by: "Roger Pau Monné" <roger.pau@citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-09-02Merge branch 'for-4.3/core' of git://git.kernel.dk/linux-blockLinus Torvalds1-2/+2
Pull core block updates from Jens Axboe: "This first core part of the block IO changes contains: - Cleanup of the bio IO error signaling from Christoph. We used to rely on the uptodate bit and passing around of an error, now we store the error in the bio itself. - Improvement of the above from myself, by shrinking the bio size down again to fit in two cachelines on x86-64. - Revert of the max_hw_sectors cap removal from a revision again, from Jeff Moyer. This caused performance regressions in various tests. Reinstate the limit, bump it to a more reasonable size instead. - Make /sys/block/<dev>/queue/discard_max_bytes writeable, by me. Most devices have huge trim limits, which can cause nasty latencies when deleting files. Enable the admin to configure the size down. We will look into having a more sane default instead of UINT_MAX sectors. - Improvement of the SGP gaps logic from Keith Busch. - Enable the block core to handle arbitrarily sized bios, which enables a nice simplification of bio_add_page() (which is an IO hot path). From Kent. - Improvements to the partition io stats accounting, making it faster. From Ming Lei. - Also from Ming Lei, a basic fixup for overflow of the sysfs pending file in blk-mq, as well as a fix for a blk-mq timeout race condition. - Ming Lin has been carrying Kents above mentioned patches forward for a while, and testing them. Ming also did a few fixes around that. - Sasha Levin found and fixed a use-after-free problem introduced by the bio->bi_error changes from Christoph. - Small blk cgroup cleanup from Viresh Kumar" * 'for-4.3/core' of git://git.kernel.dk/linux-block: (26 commits) blk: Fix bio_io_vec index when checking bvec gaps block: Replace SG_GAPS with new queue limits mask block: bump BLK_DEF_MAX_SECTORS to 2560 Revert "block: remove artifical max_hw_sectors cap" blk-mq: fix race between timeout and freeing request blk-mq: fix buffer overflow when reading sysfs file of 'pending' Documentation: update notes in biovecs about arbitrarily sized bios block: remove bio_get_nr_vecs() fs: use helper bio_add_page() instead of open coding on bi_io_vec block: kill merge_bvec_fn() completely md/raid5: get rid of bio_fits_rdev() md/raid5: split bio for chunk_aligned_read block: remove split code in blkdev_issue_{discard,write_same} btrfs: remove bio splitting and merge_bvec_fn() calls bcache: remove driver private bio splitting code block: simplify bio_add_page() block: make generic_make_request handle arbitrarily sized bios blk-cgroup: Drop unlikely before IS_ERR(_OR_NULL) block: don't access bio->bi_error after bio_put() block: shrink struct bio down to 2 cache lines again ...
2015-07-29block: add a bi_error field to struct bioChristoph Hellwig1-2/+2
Currently we have two different ways to signal an I/O error on a BIO: (1) by clearing the BIO_UPTODATE flag (2) by returning a Linux errno value to the bi_end_io callback The first one has the drawback of only communicating a single possible error (-EIO), and the second one has the drawback of not beeing persistent when bios are queued up, and are not passed along from child to parent bio in the ever more popular chaining scenario. Having both mechanisms available has the additional drawback of utterly confusing driver authors and introducing bugs where various I/O submitters only deal with one of them, and the others have to add boilerplate code to deal with both kinds of error returns. So add a new bi_error field to store an errno value directly in struct bio and remove the existing mechanisms to clean all this up. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: NeilBrown <neilb@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-07-27Merge branch 'stable/for-jens-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen into for-linusJens Axboe1-2/+2
Konrad writes: "There are three bugs that have been found in the xen-blkfront (and backend). Two of them have the stable tree CC-ed. They have been found where an guest is migrating to a host that is missing 'feature-persistent' support (from one that has it enabled). We end up hitting an BUG() in the driver code."
2015-07-24xen-blkback: replace work_pending with work_busy in purge_persistent_gnt()Bob Liu1-2/+2
The BUG_ON() in purge_persistent_gnt() will be triggered when previous purge work haven't finished. There is a work_pending() before this BUG_ON, but it doesn't account if the work is still currently running. CC: stable@vger.kernel.org Acked-by: Roger Pau Monné <roger.pau@citrix.com> Signed-off-by: Bob Liu <bob.liu@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2015-07-01Merge tag 'for-linus-4.2-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tipLinus Torvalds1-5/+5
Pull xen updates from David Vrabel: "Xen features and cleanups for 4.2-rc0: - add "make xenconfig" to assist in generating configs for Xen guests - preparatory cleanups necessary for supporting 64 KiB pages in ARM guests - automatically use hvc0 as the default console in ARM guests" * tag 'for-linus-4.2-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: block/xen-blkback: s/nr_pages/nr_segs/ block/xen-blkfront: Remove invalid comment block/xen-blkfront: Remove unused macro MAXIMUM_OUTSTANDING_BLOCK_REQS arm/xen: Drop duplicate define mfn_to_virt xen/grant-table: Remove unused macro SPP xen/xenbus: client: Fix call of virt_to_mfn in xenbus_grant_ring xen: Include xen/page.h rather than asm/xen/page.h kconfig: add xenconfig defconfig helper kconfig: clarify kvmconfig is for kvm xen/pcifront: Remove usage of struct timeval xen/tmem: use BUILD_BUG_ON() in favor of BUG_ON() hvc_xen: avoid uninitialized variable warning xenbus: avoid uninitialized variable warning xen/arm: allow console=hvc0 to be omitted for guests arm,arm64/xen: move Xen initialization earlier arm/xen: Correctly check if the event channel interrupt is present
2015-06-27Merge branch 'stable/for-jens-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen into for-linusJens Axboe1-0/+13
2015-06-17block/xen-blkback: s/nr_pages/nr_segs/Julien Grall1-5/+5
Make the code less confusing to read now that Linux may not have the same page size as Xen. Signed-off-by: Julien Grall <julien.grall@citrix.com> Acked-by: Roger Pau Monné <roger.pau@citrix.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-06-05xen/block: add multi-page ring supportBob Liu1-0/+13
Extend xen/block to support multi-page ring, so that more requests can be issued by using more than one pages as the request ring between blkfront and backend. As a result, the performance can get improved significantly. We got some impressive improvements on our highend iscsi storage cluster backend. If using 64 pages as the ring, the IOPS increased about 15 times for the throughput testing and above doubled for the latency testing. The reason was the limit on outstanding requests is 32 if use only one-page ring, but in our case the iscsi lun was spread across about 100 physical drives, 32 was really not enough to keep them busy. Changes in v2: - Rebased to 4.0-rc6. - Document on how multi-page ring feature working to linux io/blkif.h. Changes in v3: - Remove changes to linux io/blkif.h and follow the protocol defined in io/blkif.h of XEN tree. - Rebased to 4.1-rc3 Changes in v4: - Turn to use 'ring-page-order' and 'max-ring-page-order'. - A few comments from Roger. Changes in v5: - Clarify with 4k granularity to comment - Address more comments from Roger Signed-off-by: Bob Liu <bob.liu@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2015-04-27xen/grant: introduce func gnttab_unmap_refs_sync()Bob Liu1-28/+3
There are several place using gnttab async unmap and wait for completion, so move the common code to a function gnttab_unmap_refs_sync(). Signed-off-by: Bob Liu <bob.liu@oracle.com> Acked-by: Roger Pau Monné <roger.pau@citrix.com> Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-04-27xen/blkback: safely unmap purge persistent grantsBob Liu1-6/+18
Commit c43cf3ea8385 ("xen-blkback: safely unmap grants in case they are still in use") use gnttab_unmap_refs_async() to wait until the mapped pages are no longer in use before unmapping them, but that commit missed the persistent case. Purge persistent pages can't be unmapped either unless no longer in use. Signed-off-by: Bob Liu <bob.liu@oracle.com> Acked-by: Roger Pau Monné <roger.pau@citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-04-07xen-blkback: define pr_fmt macro to avoid the duplication of DRV_PFXTao Chen1-31/+31
Define pr_fmt macro with {xen-blkback: } prefix, then remove all use of DRV_PFX in the pr sentences. Replace all DPRINTK with pr sentences, and get rid of DPRINTK macro. It will simplify the code. And if the pr sentences miss a \n, add it in the end. If the DPRINTK sentences have redundant \n, remove it. It will format the code. These all make the readability of the code become better. Signed-off-by: Tao Chen <boby.chen@huawei.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Acked-by: Roger Pau Monné <roger.pau@citrix.com>
2015-01-28xen-blkback: safely unmap grants in case they are still in useJennifer Herbert1-50/+119
Use gnttab_unmap_refs_async() to wait until the mapped pages are no longer in use before unmapping them. This allows blkback to use network storage which may retain refs to pages in queued skbs after the block I/O has completed. Signed-off-by: Jennifer Herbert <jennifer.herbert@citrix.com> Acked-by: Roger Pau Monné <roger.pau@citrix.com> Acked-by: Jens Axboe <axboe@kernel.de> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-01-28xen/grant-table: add helpers for allocating pagesDavid Vrabel1-4/+4
Add gnttab_alloc_pages() and gnttab_free_pages() to allocate/free pages suitable to for granted maps. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2014-10-01xen-blkback: fix leak on grant map error pathRoger Pau Monné1-0/+1
Fix leaking a page when a grant mapping has failed. CC: stable@vger.kernel.org Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Reported-and-Tested-by: Tao Chen <boby.chen@huawei.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2014-02-11xen-blkback: init persistent_purge_work work_structRoger Pau Monne1-2/+1
Initialize persistent_purge_work work_struct on xen_blkif_alloc (and remove the previous initialization done in purge_persistent_gnt). This prevents flush_work from complaining even if purge_persistent_gnt has not been used. Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Tested-by: Sander Eikelenboom <linux@eikelenboom.it> Signed-off-by: Jens Axboe <axboe@fb.com>
2014-02-10Merge branch 'stable/for-jens-3.14' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip into for-linusJens Axboe1-21/+42
Konrad writes: Please git pull the following branch: git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip.git stable/for-jens-3.14 which is based off v3.13-rc6. If you would like me to rebase it on a different branch/tag I would be more than happy to do so. The patches are all bug-fixes and hopefully can go in 3.14. They deal with xen-blkback shutdown and cause memory leaks as well as shutdown races. They should go to stable tree and if you are OK with I will ask them to backport those fixes. There is also a fix to xen-blkfront to deal with unexpected state transition. And lastly a fix to the header where it was using the __aligned__ unnecessarily.
2014-02-07xen-blkif: drop struct blkif_request_segment_alignedRoger Pau Monne1-1/+1
This was wrongly introduced in commit 402b27f9, the only difference between blkif_request_segment_aligned and blkif_request_segment is that the former has a named padding, while both share the same memory layout. Also correct a few minor glitches in the description, including for it to no longer assume PAGE_SIZE == 4096. Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> [Description fix by Jan Beulich] Signed-off-by: Jan Beulich <jbeulich@suse.com> Reported-by: Jan Beulich <jbeulich@suse.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Tested-by: Matt Rushton <mrushton@amazon.com> Cc: Matt Wilson <msw@amazon.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2014-02-07xen-blkback: fix shutdown raceRoger Pau Monne1-10/+22
Introduce a new variable to keep track of the number of in-flight requests. We need to make sure that when xen_blkif_put is called the request has already been freed and we can safely free xen_blkif, which was not the case before. Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Tested-by: Matt Rushton <mrushton@amazon.com> Reviewed-by: Matt Rushton <mrushton@amazon.com> Cc: Matt Wilson <msw@amazon.com> Cc: Ian Campbell <Ian.Campbell@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2014-02-07xen-blkback: fix memory leaksRoger Pau Monne1-9/+18
I've at least identified two possible memory leaks in blkback, both related to the shutdown path of a VBD: - blkback doesn't wait for any pending purge work to finish before cleaning the list of free_pages. The purge work will call put_free_pages and thus we might end up with pages being added to the free_pages list after we have emptied it. Fix this by making sure there's no pending purge work before exiting xen_blkif_schedule, and moving the free_page cleanup code to xen_blkif_free. - blkback doesn't wait for pending requests to end before cleaning persistent grants and the list of free_pages. Again this can add pages to the free_pages list or persistent grants to the persistent_gnts red-black tree. Fixed by moving the persistent grants and free_pages cleanup code to xen_blkif_free. Also, add some checks in xen_blkif_free to make sure we are cleaning everything. Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Tested-by: Matt Rushton <mrushton@amazon.com> Reviewed-by: Matt Rushton <mrushton@amazon.com> Cc: Matt Wilson <msw@amazon.com> Cc: Ian Campbell <Ian.Campbell@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2014-02-07xen-blkback: fix memory leak when persistent grants are usedMatt Rushton1-3/+3
Currently shrink_free_pagepool() is called before the pages used for persistent grants are released via free_persistent_gnts(). This results in a memory leak when a VBD that uses persistent grants is torn down. Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: "Roger Pau Monné" <roger.pau@citrix.com> Cc: Ian Campbell <Ian.Campbell@citrix.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Cc: linux-kernel@vger.kernel.org Cc: xen-devel@lists.xen.org Cc: Anthony Liguori <aliguori@amazon.com> Signed-off-by: Matt Rushton <mrushton@amazon.com> Signed-off-by: Matt Wilson <msw@amazon.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-11-23block: Abstract out bvec iteratorKent Overstreet1-1/+1
Immutable biovecs are going to require an explicit iterator. To implement immutable bvecs, a later patch is going to add a bi_bvec_done member to this struct; for now, this patch effectively just renames things. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: "Ed L. Cashin" <ecashin@coraid.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Lars Ellenberg <drbd-dev@lists.linbit.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Yehuda Sadeh <yehuda@inktank.com> Cc: Sage Weil <sage@inktank.com> Cc: Alex Elder <elder@inktank.com> Cc: ceph-devel@vger.kernel.org Cc: Joshua Morris <josh.h.morris@us.ibm.com> Cc: Philip Kelleher <pjk1939@linux.vnet.ibm.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Neil Brown <neilb@suse.de> Cc: Alasdair Kergon <agk@redhat.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: dm-devel@redhat.com Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux390@de.ibm.com Cc: Boaz Harrosh <bharrosh@panasas.com> Cc: Benny Halevy <bhalevy@tonian.com> Cc: "James E.J. Bottomley" <JBottomley@parallels.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Chris Mason <chris.mason@fusionio.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Jaegeuk Kim <jaegeuk.kim@samsung.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Dave Kleikamp <shaggy@kernel.org> Cc: Joern Engel <joern@logfs.org> Cc: Prasad Joshi <prasadjoshi.linux@gmail.com> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Ben Myers <bpm@sgi.com> Cc: xfs@oss.sgi.com Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Len Brown <len.brown@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Guo Chao <yan@linux.vnet.ibm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Cc: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Cc: "Roger Pau Monné" <roger.pau@citrix.com> Cc: Jan Beulich <jbeulich@suse.com> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Cc: Ian Campbell <Ian.Campbell@citrix.com> Cc: Sebastian Ott <sebott@linux.vnet.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Jerome Marchand <jmarchand@redhat.com> Cc: Joe Perches <joe@perches.com> Cc: Peng Tao <tao.peng@emc.com> Cc: Andy Adamson <andros@netapp.com> Cc: fanchaoting <fanchaoting@cn.fujitsu.com> Cc: Jie Liu <jeff.liu@oracle.com> Cc: Sunil Mushran <sunil.mushran@gmail.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Namjae Jeon <namjae.jeon@samsung.com> Cc: Pankaj Kumar <pankaj.km@samsung.com> Cc: Dan Magenheimer <dan.magenheimer@oracle.com> Cc: Mel Gorman <mgorman@suse.de>6
2013-11-08xen/blkback: fix reference countingVegard Nossum1-1/+2
If the permission check fails, we drop a reference to the blkif without having taken it in the first place. The bug was introduced in commit 604c499cbbcc3d5fe5fb8d53306aa0fae1990109 (xen/blkback: Check device permissions before allowing OP_DISCARD). Cc: stable@vger.kernel.org Cc: Jan Beulich <JBeulich@suse.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-06-25xen-blkback: check the number of iovecs before allocating a biosRoger Pau Monne1-1/+2
With the introduction of indirect segments we can receive requests with a number of segments bigger than the maximum number of allowed iovecs in a bios, so make sure that blkback doesn't try to allocate a bios with more iovecs than BIO_MAX_PAGES Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-06-21xen-blkback: workaround compiler bug in gcc 4.1Roger Pau Monne1-10/+14
The code generat with gcc (GCC) 4.1.2 20080704 (Red Hat 4.1.2-54) creates an unbound loop for the second foreach_grant_safe loop in purge_persistent_gnt. The workaround is to avoid having this second loop and instead perform all the work inside the first loop by adding a new variable, clean_used, that will be set when all the desired persistent grants have been removed and we need to iterate over the remaining ones to remove the WAS_ACTIVE flag. Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Reported-by: Tom O'Neill <toneill@vmem.com> Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-06-17xen/blkback: Check for insane amounts of request on the ring (v6).Konrad Rzeszutek Wilk1-1/+12
Check that the ring does not have an insane amount of requests (more than there could fit on the ring). If we detect this case we will stop processing the requests and wait until the XenBus disconnects the ring. The existing check RING_REQUEST_CONS_OVERFLOW which checks for how many responses we have created in the past (rsp_prod_pvt) vs requests consumed (req_cons) and whether said difference is greater or equal to the size of the ring, does not catch this case. Wha the condition does check if there is a need to process more as we still have a backlog of responses to finish. Note that both of those values (rsp_prod_pvt and req_cons) are not exposed on the shared ring. To understand this problem a mini crash course in ring protocol response/request updates is in place. There are four entries: req_prod and rsp_prod; req_event and rsp_event to track the ring entries. We are only concerned about the first two - which set the tone of this bug. The req_prod is a value incremented by frontend for each request put on the ring. Conversely the rsp_prod is a value incremented by the backend for each response put on the ring (rsp_prod gets set by rsp_prod_pvt when pushing the responses on the ring). Both values can wrap and are modulo the size of the ring (in block case that is 32). Please see RING_GET_REQUEST and RING_GET_RESPONSE for the more details. The culprit here is that if the difference between the req_prod and req_cons is greater than the ring size we have a problem. Fortunately for us, the '__do_block_io_op' loop: rc = blk_rings->common.req_cons; rp = blk_rings->common.sring->req_prod; while (rc != rp) { .. blk_rings->common.req_cons = ++rc; /* before make_response() */ } will loop up to the point when rc == rp. The macros inside of the loop (RING_GET_REQUEST) is smart and is indexing based on the modulo of the ring size. If the frontend has provided a bogus req_prod value we will loop until the 'rc == rp' - which means we could be processing already processed requests (or responses) often. The reason the RING_REQUEST_CONS_OVERFLOW is not helping here is b/c it only tracks how many responses we have internally produced and whether we would should process more. The astute reader will notice that the macro RING_REQUEST_CONS_OVERFLOW provides two arguments - more on this later. For example, if we were to enter this function with these values: blk_rings->common.sring->req_prod = X+31415 (X is the value from the last time __do_block_io_op was called). blk_rings->common.req_cons = X blk_rings->common.rsp_prod_pvt = X The RING_REQUEST_CONS_OVERFLOW(&blk_rings->common, blk_rings->common.req_cons) is doing: req_cons - rsp_prod_pvt >= 32 Which is, X - X >= 32 or 0 >= 32 And that is false, so we continue on looping (this bug). If we re-use said macro RING_REQUEST_CONS_OVERFLOW and pass in the rp instead (sring->req_prod) of rc, the this macro can do the check: req_prod - rsp_prov_pvt >= 32 Which is, X + 31415 - X >= 32 , or 31415 >= 32 which is true, so we can error out and break out of the function. Unfortunatly the difference between rsp_prov_pvt and req_prod can be at 32 (which would error out in the macro). This condition exists when the backend is lagging behind with the responses and still has not finished responding to all of them (so make_response has not been called), and the rsp_prov_pvt + 32 == req_cons. This ends up with us not being able to use said macro. Hence introducing a new macro called RING_REQUEST_PROD_OVERFLOW which does a simple check of: req_prod - rsp_prod_pvt > RING_SIZE And with the X values from above: X + 31415 - X > 32 Returns true. Also not that if the ring is full (which is where the RING_REQUEST_CONS_OVERFLOW triggered), we would not hit the same condition: X + 32 - X > 32 Which is false. Lets use that macro. Note that in v5 of this patchset the macro was different - we used an earlier version. Cc: stable@vger.kernel.org [v1: Move the check outside the loop] [v2: Add a pr_warn as suggested by David] [v3: Use RING_REQUEST_CONS_OVERFLOW as suggested by Jan] [v4: Move wake_up after kthread_stop as suggested by Jan] [v5: Use RING_REQUEST_PROD_OVERFLOW instead] [v6: Use RING_REQUEST_PROD_OVERFLOW - Jan's version] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> gadsa
2013-06-07xen/blkback: Check device permissions before allowing OP_DISCARDKonrad Rzeszutek Wilk1-1/+12
We need to make sure that the device is not RO or that the request is not past the number of sectors we want to issue the DISCARD operation for. This fixes CVE-2013-2140. Cc: stable@vger.kernel.org Acked-by: Jan Beulich <JBeulich@suse.com> Acked-by: Ian Campbell <Ian.Campbell@citrix.com> [v1: Made it pr_warn instead of pr_debug] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-05-07xen-blkback: allocate list of pending reqs in small chunksRoger Pau Monne1-52/+40
Allocate pending requests in smaller chunks instead of allocating them all at the same time. This change also removes the global array of pending_reqs, it is no longer necessay. Variables related to the grant mapping have been grouped into a struct called "grant_page", this allows to allocate them in smaller chunks, and also improves memory locality. Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Reported-by: Sander Eikelenboom <linux@eikelenboom.it> Tested-by: Sander Eikelenboom <linux@eikelenboom.it> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-04-18xen-block: implement indirect descriptorsRoger Pau Monne1-36/+98
Indirect descriptors introduce a new block operation (BLKIF_OP_INDIRECT) that passes grant references instead of segments in the request. This grant references are filled with arrays of blkif_request_segment_aligned, this way we can send more segments in a request. The proposed implementation sets the maximum number of indirect grefs (frames filled with blkif_request_segment_aligned) to 256 in the backend and 32 in the frontend. The value in the frontend has been chosen experimentally, and the backend value has been set to a sane value that allows expanding the maximum number of indirect descriptors in the frontend if needed. The migration code has changed from the previous implementation, in which we simply remapped the segments on the shared ring. Now the maximum number of segments allowed in a request can change depending on the backend, so we have to requeue all the requests in the ring and in the queue and split the bios in them if they are bigger than the new maximum number of segments. [v2: Fixed minor comments by Konrad. [v1: Added padding to make the indirect request 64bit aligned. Added some BUGs, comments; fixed number of indirect pages in blkif_get_x86_{32/64}_req. Added description about the indirect operation in blkif.h] Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> [v3: Fixed spaces and tabs mix ups] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>