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The ORC metadata generated for UNWIND_HINT_FUNC isn't actually very
func-like. With certain usages it can cause stack state mismatches
because it doesn't set the return address (CFI_RA).
Also, users of UNWIND_HINT_RET_OFFSET no longer need to set a custom
return stack offset. Instead they just need to specify a func-like
situation, so the current ret_offset code is hacky for no good reason.
Solve both problems by simplifying the RET_OFFSET handling and
converting it into a more useful UNWIND_HINT_FUNC.
If we end up needing the old 'ret_offset' functionality again in the
future, we should be able to support it pretty easily with the addition
of a custom 'sp_offset' in UNWIND_HINT_FUNC.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/db9d1f5d79dddfbb3725ef6d8ec3477ad199948d.1611263462.git.jpoimboe@redhat.com
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To be used for adding asm functions to the ignore list. The "aw" is
needed to help the ELF section metadata match GCC-created sections.
Otherwise the linker creates duplicate sections instead of combining
them.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/8faa476f9a5ac89af27944ec184c89f95f3c6c49.1611263462.git.jpoimboe@redhat.com
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Linux 5.11-rc2
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Correct kernel-doc notation in HID header files (include/linux/hid*.h).
Add notation (comments) where it is missing.
Use the documented "Return:" notation for function return values.
Fix a few typos/spellos.
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc: linux-input@vger.kernel.org
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
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The driver core ignores the return value of the remove callback, so
don't give isa drivers the chance to provide a value.
Adapt all isa_drivers with a remove callbacks accordingly; they all
return 0 unconditionally anyhow.
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> # for drivers/net/can/sja1000/tscan1.c
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Acked-by: Wolfram Sang <wsa@kernel.org> # for drivers/i2c/
Reviewed-by: Takashi Iway <tiwai@suse.de> # for sound/
Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> # for drivers/media/
Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Link: https://lore.kernel.org/r/20210122092449.426097-4-uwe@kleine-koenig.org
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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Use nf_ct_get() directly, its a small inline helper without dependencies.
Add CONFIG_NF_CONNTRACK guards to elide the relevant part when conntrack
isn't available at all.
v2: add ifdef guard around nf_ct_get call (kernel test robot)
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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Remove duplicated helper functions to parse opaque XDR objects
and place inside new file net/sunrpc/auth_gss/auth_gss_internal.h.
In the new file carry the license and copyright from the source file
net/sunrpc/auth_gss/auth_gss.c. Finally, update the comment inside
include/linux/sunrpc/xdr.h since lockd is not the only user of
struct xdr_netobj.
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
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layer to use write_iter. Fix the redirected_tty_write declaration
also in n_tty and change the comparisons to use write_iter instead of
write.
[ Also moved the declaration of redirected_tty_write() to the proper
location in a header file. The reason for the bug was the bogus extern
declaration in n_tty.c silently not matching the changed definition in
tty_io.c, and because it wasn't in a shared header file, there was no
cross-checking of the declaration.
Sami noticed because Clang's Control Flow Integrity checking ended up
incidentally noticing the inconsistent declaration. - Linus ]
Fixes: 9bb48c82aced ("tty: implement write_iter")
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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NVIDIA Tegra DRM and media drivers will need a resource-managed-optional
variant of reset_control_get_exclusive_released() in order to switch away
from a legacy Tegra-specific PD API to a GENPD API without much hassle.
Add the new reset helper to the reset API.
Tested-by: Peter Geis <pgwipeout@gmail.com> # Ouya T30
Tested-by: Nicolas Chauvet <kwizart@gmail.com> # PAZ00 T20
Tested-by: Matt Merhar <mattmerhar@protonmail.com> # Ouya T30
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
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Drop the const qualifier from the static global cur_profile
pointer declaration.
This is a preparation patch for passing the cur_profile pointer as
parameter to the profile_get() and profile_set() callbacks so that
drivers dynamically allocating their driver-data struct, with their
platform_profile_handler struct embedded, can use this pointer to
get to their driver-data.
Note this also requires dropping the const from the pprof
platform_profile_register() function argument. Dropping this
const is not a problem, non of the queued up consumers of
platform_profile_register() actually pass in a const pointer.
Link: https://lore.kernel.org/linux-acpi/5e7a4d87-52ef-e487-9cc2-8e7094beaa08@redhat.com/
Link: https://lore.kernel.org/r/20210114073429.176462-2-jiaxun.yang@flygoat.com
Suggested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
[ hdegoede@redhat.com: Also remove const from platform_profile_register() ]
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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The block layer spends quite a while in blkdev_direct_IO() to copy and
initialise bio's bvec. However, if we've already got a bvec in the input
iterator it might be reused in some cases, i.e. when new
ITER_BVEC_FLAG_FIXED flag is set. Simple tests show considerable
performance boost, and it also reduces memory footprint.
Suggested-by: Matthew Wilcox <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Add a helper function calculating the number of bvec segments we need to
allocate to construct a bio. It doesn't change anything functionally,
but will be used to not duplicate special cases in the future.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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This is similar to commit e340c2d6ef2a ("xprtrdma: Reduce the
doorbell rate (Receive)") which added Receive batching to the
client.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
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Clean up. We are not permitted to remove old proc files. Instead,
convert these variables to stubs that are only ever allowed to
display a value of zero.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
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Now that we have an efficient mechanism to update these two stats,
let's start maintaining them again.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
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Avoid the overhead of a memory bus lock cycle for counting a value
that is hardly every used.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
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Receives are frequent events. Avoid the overhead of a memory bus
lock cycle for counting a value that is hardly every used.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
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Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
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Clean up: The unit of XDR alignment is defined by RFC 4506,
not as part of the RPC message header. Thus it belongs in
include/linux/sunrpc/xdr.h.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
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The next few patches will employ these strings to help make server-
side trace logs more human-readable. A similar technique is already
in use in kernel RPC client code.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
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If the port partner is PD2, the PDOs of the local port should follow the
format defined in PD2 Spec. Dynamically modify the pre-defined PD3 PDOs
and transform them into PD2 format before sending them to the PD2 port
partner.
Reviewed-by: Guenter Roeck <linux@roeckus.net>
Signed-off-by: Kyle Tso <kyletso@google.com>
Link: https://lore.kernel.org/r/20210115163311.391332-1-kyletso@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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We need the fixes in here and this resolves a merge issue with
drivers/usb/gadget/udc/bdc/Kconfig.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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We need the fixes in here and this resolves a merge issue in
drivers/tty/tty_io.c
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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We need the IIO/Staging fixes in here as well.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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We can remove 'q' from blk_execute_rq as well after the previous change
in blk_execute_rq_nowait.
And more importantly it never really was needed to start with given
that we can trivial derive it from struct request.
Cc: linux-scsi@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org
Cc: linux-ide@vger.kernel.org
Cc: linux-mmc@vger.kernel.org
Cc: linux-nvme@lists.infradead.org
Cc: linux-nfs@vger.kernel.org
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc
Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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The 'q' is not used since commit a1ce35fa4985 ("block: remove dead
elevator code"), also update the comment of the function.
And more importantly it never really was needed to start with given
that we can trivial derive it from struct request.
Cc: target-devel@vger.kernel.org
Cc: linux-scsi@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org
Cc: linux-ide@vger.kernel.org
Cc: linux-mmc@vger.kernel.org
Cc: linux-nvme@lists.infradead.org
Cc: linux-nfs@vger.kernel.org
Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux into drm-next
Backmerge v5.11-rc5 into drm-next to clean up a bunch of conflicts we are dragging around.
Signed-off-by: Dave Airlie <airlied@redhat.com>
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bvec_alloc(), bvec_free() and bvec_nr_vecs() are only used inside block
layer core functions, no need to declare them in public header.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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The inline bvecs won't be used if user needn't bvecs by not passing
BIOSET_NEED_BVECS, so don't allocate bvecs in this situation.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Tested-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Currently when non-mq aware IO scheduler (BFQ, mq-deadline) is used for
a queue with multiple HW queues, the performance it rather bad. The
problem is that these IO schedulers use queue-wide locking and their
dispatch function does not respect the hctx it is passed in and returns
any request it finds appropriate. Thus locality of request access is
broken and dispatch from multiple CPUs just contends on IO scheduler
locks. For these IO schedulers there's little point in dispatching from
multiple CPUs. Instead dispatch always only from a single CPU to limit
contention.
Below is a comparison of dbench runs on XFS filesystem where the storage
is a raid card with 64 HW queues and to it attached a single rotating
disk. BFQ is used as IO scheduler:
clients MQ SQ MQ-Patched
Amean 1 39.12 (0.00%) 43.29 * -10.67%* 36.09 * 7.74%*
Amean 2 128.58 (0.00%) 101.30 * 21.22%* 96.14 * 25.23%*
Amean 4 577.42 (0.00%) 494.47 * 14.37%* 508.49 * 11.94%*
Amean 8 610.95 (0.00%) 363.86 * 40.44%* 362.12 * 40.73%*
Amean 16 391.78 (0.00%) 261.49 * 33.25%* 282.94 * 27.78%*
Amean 32 324.64 (0.00%) 267.71 * 17.54%* 233.00 * 28.23%*
Amean 64 295.04 (0.00%) 253.02 * 14.24%* 242.37 * 17.85%*
Amean 512 10281.61 (0.00%) 10211.16 * 0.69%* 10447.53 * -1.61%*
Numbers are times so lower is better. MQ is stock 5.10-rc6 kernel. SQ is
the same kernel with megaraid_sas.host_tagset_enable=0 so that the card
advertises just a single HW queue. MQ-Patched is a kernel with this
patch applied.
You can see multiple hardware queues heavily hurt performance in
combination with BFQ. The patch restores the performance.
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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This reverts commit b445547ec1bbd3e7bf4b1c142550942f70527d95.
Since both mq-deadline and BFQ completely ignore hctx they are passed to
their dispatch function and dispatch whatever request they deem fit
checking whether any request for a particular hctx is queued is just
pointless since we'll very likely get a request from a different hctx
anyway. In the following commit we'll deal with lock contention in these
IO schedulers in presence of multiple HW queues in a different way.
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Now that no fast path lookups in the partition table are left, there is
no point in micro-optimizing the data structure for it. Just use a bog
standard xarray.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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There is good reason to iterate backwards when deleting all partitions in
del_gendisk, just like we don't in blk_drop_partitions.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Add a helper to call kobject_uevent for the disk and all partitions, and
unexport the disk_part_iter_* helpers that are now only used in the core
block code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Rework the I/O accounting for bio based drivers to use ->bi_bdev. This
means all drivers can now simply use bio_start_io_acct to start
accounting, and it will take partitions into account automatically. To
end I/O account either bio_end_io_acct can be used if the driver never
remaps I/O to a different device, or bio_end_io_acct_remapped if the
driver did remap the I/O.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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There is no good reason to reassign ->bi_bdev when remapping the
partition-relative block number to the device wide one, as all the
information required by the drivers comes from the gendisk anyway.
Keeping the original ->bi_bdev alive will allow to greatly simplify
the partition-away I/O accounting.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Replace the gendisk pointer in struct bio with a pointer to the newly
improved struct block device. From that the gendisk can be trivially
accessed with an extra indirection, but it also allows to directly
look up all information related to partition remapping.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Commit 20bd1d026aac ("scsi: sd: Keep disk read-only when re-reading
partition") addressed a long-standing problem with user read-only
policy being overridden as a result of a device-initiated revalidate.
The commit has since been reverted due to a regression that left some
USB devices read-only indefinitely.
To fix the underlying problems with revalidate we need to keep track
of hardware state and user policy separately.
The gendisk has been updated to reflect the current hardware state set
by the device driver. This is done to allow returning the device to
the hardware state once the user clears the BLKROSET flag.
The resulting semantics are as follows:
- If BLKROSET sets a given partition read-only, that partition will
remain read-only even if the underlying storage stack initiates a
revalidate. However, the BLKRRPART ioctl will cause the partition
table to be dropped and any user policy on partitions will be lost.
- If BLKROSET has not been set, both the whole disk device and any
partitions will reflect the current write-protect state of the
underlying device.
Based on a patch from Martin K. Petersen <martin.petersen@oracle.com>.
Reported-by: Oleksii Kurochko <olkuroch@cisco.com>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=201221
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Pull block fixes from Jens Axboe:
- NVMe pull request from Christoph:
- fix a status code in nvmet (Chaitanya Kulkarni)
- avoid double completions in nvme-rdma/nvme-tcp (Chao Leng)
- fix the CMB support to cope with NVMe 1.4 controllers (Klaus Jensen)
- fix PRINFO handling in the passthrough ioctl (Revanth Rajashekar)
- fix a double DMA unmap in nvme-pci
- lightnvm error path leak fix (Pan)
- MD pull request from Song:
- Flush request fix (Xiao)
* tag 'block-5.11-2021-01-24' of git://git.kernel.dk/linux-block:
lightnvm: fix memory leak when submit fails
nvme-pci: fix error unwind in nvme_map_data
nvme-pci: refactor nvme_unmap_data
md: Set prev_flush_start and flush_bio in an atomic way
nvmet: set right status on error in id-ns handler
nvme-pci: allow use of cmb on v1.4 controllers
nvme-tcp: avoid request double completion for concurrent nvme_tcp_timeout
nvme-rdma: avoid request double completion for concurrent nvme_rdma_timeout
nvme: check the PRINFO bit before deciding the host buffer length
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core fixes from Greg KH:
"Here are some small driver core fixes for 5.11-rc5 that resolve some
reported problems:
- revert of a -rc1 patch that was causing problems with some machines
- device link device name collision problem fix (busses only have to
name devices unique to their bus, not unique to all busses)
- kernfs splice bugfixes to resolve firmware loading problems for
Qualcomm systems.
- other tiny driver core fixes for minor issues reported.
All of these have been in linux-next with no reported problems"
* tag 'driver-core-5.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
driver core: Fix device link device name collision
driver core: Extend device_is_dependent()
kernfs: wire up ->splice_read and ->splice_write
kernfs: implement ->write_iter
kernfs: implement ->read_iter
Revert "driver core: Reorder devices on successful probe"
Driver core: platform: Add extra error check in devm_platform_get_irqs_affinity()
drivers core: Free dma_range_map when driver probe failed
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Borislav Petkov:
- Correct the marking of kthreads which are supposed to run on a
specific, single CPU vs such which are affine to only one CPU, mark
per-cpu workqueue threads as such and make sure that marking
"survives" CPU hotplug. Fix CPU hotplug issues with such kthreads.
- A fix to not push away tasks on CPUs coming online.
- Have workqueue CPU hotplug code use cpu_possible_mask when breaking
affinity on CPU offlining so that pending workers can finish on newly
arrived onlined CPUs too.
- Dump tasks which haven't vacated a CPU which is currently being
unplugged.
- Register a special scale invariance callback which gets called on
resume from RAM to read out APERF/MPERF after resume and thus make
the schedutil scaling governor more precise.
* tag 'sched_urgent_for_v5.11_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched: Relax the set_cpus_allowed_ptr() semantics
sched: Fix CPU hotplug / tighten is_per_cpu_kthread()
sched: Prepare to use balance_push in ttwu()
workqueue: Restrict affinity change to rescuer
workqueue: Tag bound workers with KTHREAD_IS_PER_CPU
kthread: Extract KTHREAD_IS_PER_CPU
sched: Don't run cpu-online with balance_push() enabled
workqueue: Use cpu_possible_mask instead of cpu_active_mask to break affinity
sched/core: Print out straggler tasks in sched_cpu_dying()
x86: PM: Register syscore_ops for scale invariance
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Borislav Petkov:
- Fix an integer overflow in the NTP RTC synchronization which led to
the latter happening every 2 seconds instead of the intended every 11
minutes.
- Get rid of now unused get_seconds().
* tag 'timers_urgent_for_v5.11_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
ntp: Fix RTC synchronization on 32-bit platforms
timekeeping: Remove unused get_seconds()
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Introduce a new mount bind mount property to allow idmapping mounts. The
MOUNT_ATTR_IDMAP flag can be set via the new mount_setattr() syscall
together with a file descriptor referring to a user namespace.
The user namespace referenced by the namespace file descriptor will be
attached to the bind mount. All interactions with the filesystem going
through that mount will be mapped according to the mapping specified in
the user namespace attached to it.
Using user namespaces to mark mounts means we can reuse all the existing
infrastructure in the kernel that already exists to handle idmappings
and can also use this for permission checking to allow unprivileged user
to create idmapped mounts in the future.
Idmapping a mount is decoupled from the caller's user and mount
namespace. This means idmapped mounts can be created in the initial
user namespace which is an important use-case for systemd-homed,
portable usb-sticks between systems, sharing data between the initial
user namespace and unprivileged containers, and other use-cases that
have been brought up. For example, assume a home directory where all
files are owned by uid and gid 1000 and the home directory is brought to
a new laptop where the user has id 12345. The system administrator can
simply create a mount of this home directory with a mapping of
1000:12345:1 and other mappings to indicate the ids should be kept.
(With this it is e.g. also possible to create idmapped mounts on the
host with an identity mapping 1:1:100000 where the root user is not
mapped. A user with root access that e.g. has been pivot rooted into
such a mount on the host will be not be able to execute, read, write, or
create files as root.)
Given that mapping a mount is decoupled from the caller's user namespace
a sufficiently privileged process such as a container manager can set up
an idmapped mount for the container and the container can simply pivot
root to it. There's no need for the container to do anything. The mount
will appear correctly mapped independent of the user namespace the
container uses. This means we don't need to mark a mount as idmappable.
In order to create an idmapped mount the caller must currently be
privileged in the user namespace of the superblock the mount belongs to.
Once a mount has been idmapped we don't allow it to change its mapping.
This keeps permission checking and life-cycle management simple. Users
wanting to change the idmapped can always create a new detached mount
with a different idmapping.
Link: https://lore.kernel.org/r/20210121131959.646623-36-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Mauricio Vásquez Bernal <mauricio@kinvolk.io>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
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This implements the missing mount_setattr() syscall. While the new mount
api allows to change the properties of a superblock there is currently
no way to change the properties of a mount or a mount tree using file
descriptors which the new mount api is based on. In addition the old
mount api has the restriction that mount options cannot be applied
recursively. This hasn't changed since changing mount options on a
per-mount basis was implemented in [1] and has been a frequent request
not just for convenience but also for security reasons. The legacy
mount syscall is unable to accommodate this behavior without introducing
a whole new set of flags because MS_REC | MS_REMOUNT | MS_BIND |
MS_RDONLY | MS_NOEXEC | [...] only apply the mount option to the topmost
mount. Changing MS_REC to apply to the whole mount tree would mean
introducing a significant uapi change and would likely cause significant
regressions.
The new mount_setattr() syscall allows to recursively clear and set
mount options in one shot. Multiple calls to change mount options
requesting the same changes are idempotent:
int mount_setattr(int dfd, const char *path, unsigned flags,
struct mount_attr *uattr, size_t usize);
Flags to modify path resolution behavior are specified in the @flags
argument. Currently, AT_EMPTY_PATH, AT_RECURSIVE, AT_SYMLINK_NOFOLLOW,
and AT_NO_AUTOMOUNT are supported. If useful, additional lookup flags to
restrict path resolution as introduced with openat2() might be supported
in the future.
The mount_setattr() syscall can be expected to grow over time and is
designed with extensibility in mind. It follows the extensible syscall
pattern we have used with other syscalls such as openat2(), clone3(),
sched_{set,get}attr(), and others.
The set of mount options is passed in the uapi struct mount_attr which
currently has the following layout:
struct mount_attr {
__u64 attr_set;
__u64 attr_clr;
__u64 propagation;
__u64 userns_fd;
};
The @attr_set and @attr_clr members are used to clear and set mount
options. This way a user can e.g. request that a set of flags is to be
raised such as turning mounts readonly by raising MOUNT_ATTR_RDONLY in
@attr_set while at the same time requesting that another set of flags is
to be lowered such as removing noexec from a mount tree by specifying
MOUNT_ATTR_NOEXEC in @attr_clr.
Note, since the MOUNT_ATTR_<atime> values are an enum starting from 0,
not a bitmap, users wanting to transition to a different atime setting
cannot simply specify the atime setting in @attr_set, but must also
specify MOUNT_ATTR__ATIME in the @attr_clr field. So we ensure that
MOUNT_ATTR__ATIME can't be partially set in @attr_clr and that @attr_set
can't have any atime bits set if MOUNT_ATTR__ATIME isn't set in
@attr_clr.
The @propagation field lets callers specify the propagation type of a
mount tree. Propagation is a single property that has four different
settings and as such is not really a flag argument but an enum.
Specifically, it would be unclear what setting and clearing propagation
settings in combination would amount to. The legacy mount() syscall thus
forbids the combination of multiple propagation settings too. The goal
is to keep the semantics of mount propagation somewhat simple as they
are overly complex as it is.
The @userns_fd field lets user specify a user namespace whose idmapping
becomes the idmapping of the mount. This is implemented and explained in
detail in the next patch.
[1]: commit 2e4b7fcd9260 ("[PATCH] r/o bind mounts: honor mount writer counts at remount")
Link: https://lore.kernel.org/r/20210121131959.646623-35-christian.brauner@ubuntu.com
Cc: David Howells <dhowells@redhat.com>
Cc: Aleksa Sarai <cyphar@cyphar.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-api@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
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IMA does sometimes access the inode's i_uid and compares it against the
rules' fowner. Enable IMA to handle idmapped mounts by passing down the
mount's user namespace. We simply make use of the helpers we introduced
before. If the initial user namespace is passed nothing changes so
non-idmapped mounts will see identical behavior as before.
Link: https://lore.kernel.org/r/20210121131959.646623-27-christian.brauner@ubuntu.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
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Extend some inode methods with an additional user namespace argument. A
filesystem that is aware of idmapped mounts will receive the user
namespace the mount has been marked with. This can be used for
additional permission checking and also to enable filesystems to
translate between uids and gids if they need to. We have implemented all
relevant helpers in earlier patches.
As requested we simply extend the exisiting inode method instead of
introducing new ones. This is a little more code churn but it's mostly
mechanical and doesnt't leave us with additional inode methods.
Link: https://lore.kernel.org/r/20210121131959.646623-25-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
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When truncating files the vfs will verify that the caller is privileged
over the inode. Extend it to handle idmapped mounts. If the inode is
accessed through an idmapped mount it is mapped according to the mount's
user namespace. Afterwards the permissions checks are identical to
non-idmapped mounts. If the initial user namespace is passed nothing
changes so non-idmapped mounts will see identical behavior as before.
Link: https://lore.kernel.org/r/20210121131959.646623-16-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
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The various vfs_*() helpers are called by filesystems or by the vfs
itself to perform core operations such as create, link, mkdir, mknod, rename,
rmdir, tmpfile and unlink. Enable them to handle idmapped mounts. If the
inode is accessed through an idmapped mount map it into the
mount's user namespace and pass it down. Afterwards the checks and
operations are identical to non-idmapped mounts. If the initial user
namespace is passed nothing changes so non-idmapped mounts will see
identical behavior as before.
Link: https://lore.kernel.org/r/20210121131959.646623-15-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
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In order to handle idmapped mounts we will extend the vfs rename helper
to take two new arguments in follow up patches. Since this operations
already takes a bunch of arguments add a simple struct renamedata and
make the current helper use it before we extend it.
Link: https://lore.kernel.org/r/20210121131959.646623-14-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
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The may_follow_link(), may_linkat(), may_lookup(), may_open(),
may_o_create(), may_create_in_sticky(), may_delete(), and may_create()
helpers determine whether the caller is privileged enough to perform the
associated operations. Let them handle idmapped mounts by mapping the
inode or fsids according to the mount's user namespace. Afterwards the
checks are identical to non-idmapped inodes. The patch takes care to
retrieve the mount's user namespace right before performing permission
checks and passing it down into the fileystem so the user namespace
can't change in between by someone idmapping a mount that is currently
not idmapped. If the initial user namespace is passed nothing changes so
non-idmapped mounts will see identical behavior as before.
Link: https://lore.kernel.org/r/20210121131959.646623-13-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
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