Force the lock context to keep a reference to the parent open
context so that we can guarantee the validity of the latter.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
If the server is unable to immediately execute an RPC call, and returns
an NFS4ERR_DELAY then we can assume it is safe to interrupt the operation
in order to handle ordinary signals. This allows the application to
service timer interrupts that would otherwise have to wait until the
server is again able to respond.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
When the client is reading or writing using pNFS, and hits an error
on the DS, then it typically sends a LAYOUTERROR and/or LAYOUTRETURN
to the MDS, before redirtying the failed pages, and going for a new
round of reads/writebacks. The problem is that if the server has no
way to fix the DS, then we may need a way to interrupt this loop
after a set number of attempts have been made.
This patch adds an optional module parameter that allows the admin
to specify how many times to retry the read/writeback process before
failing with a fatal error.
The default behaviour is to retry forever.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
All the callers of nfs_create_request() are now creating page group
heads, so we can remove the redundant 'last' page argument.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
We require all NFS I/O subrequests to duplicate the lock context as well
as the open context.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Replace the NFS custom error reporting mechanism with the generic
mapping_set_error().
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
vfs_fsync() has the side effect of clearing unreported writeback errors,
so we need to make sure that we do not abuse it in situations where
applications might not normally expect us to report those errors.
The solution is to replace calls to vfs_fsync() with calls to nfs_wb_all().
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
The NFS read code can trigger writeback while holding the page lock.
If an error then triggers a call to nfs_write_error_remove_page(),
we can deadlock.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
When flushing out dirty pages, the fact that we may hit fatal errors
is not a reason to stop writeback. Those errors are reported through
fsync(), not through the flush mechanism.
Fixes: a6598813a4 ("NFS: Don't write back further requests if there...")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Add a mount option that exposes the ETIMEDOUT errors that occur during
soft timeouts to the application. This allows aware applications to
distinguish between server disk IO errors and client timeout errors.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
When we introduce the 'softerr' mount option, we will see the RPC
layer returning ETIMEDOUT errors if the server is unresponsive. We
want to consider those errors to be fatal on par with the EIO errors
that are returned by ordinary 'soft' timeouts..
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Clean up the RPC task sleep interfaces by replacing the task->tk_timeout
'hidden parameter' to rpc_sleep_on() with a new function that takes an
absolute timeout.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
None of the callers set the 'action' argument, so let's just remove it.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
The RPC_TASK_KILLED flag should really not be set from another context
because it can clobber data in the struct task when task->tk_flags is
changed non-atomically.
Let's therefore swap out RPC_TASK_KILLED with an atomic flag, and add
a function to set that flag and safely wake up the task.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
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Merge tag 'for-linus-20190420' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe:
"A set of small fixes that should go into this series. This contains:
- Removal of unused queue member (Hou)
- Overflow bvec fix (Ming)
- Various little io_uring tweaks (me)
- kthread parking
- Only call cpu_possible() for verified CPU
- Drop unused 'file' argument to io_file_put()
- io_uring_enter vs io_uring_register deadlock fix
- CQ overflow fix
- BFQ internal depth update fix (me)"
* tag 'for-linus-20190420' of git://git.kernel.dk/linux-block:
block: make sure that bvec length can't be overflow
block: kill all_q_node in request_queue
io_uring: fix CQ overflow condition
io_uring: fix possible deadlock between io_uring_{enter,register}
io_uring: drop io_file_put() 'file' argument
bfq: update internal depth state when queue depth changes
io_uring: only test SQPOLL cpu after we've verified it
io_uring: park SQPOLL thread if it's percpu
The core dumping code has always run without holding the mmap_sem for
writing, despite that is the only way to ensure that the entire vma
layout will not change from under it. Only using some signal
serialization on the processes belonging to the mm is not nearly enough.
This was pointed out earlier. For example in Hugh's post from Jul 2017:
https://lkml.kernel.org/r/alpine.LSU.2.11.1707191716030.2055@eggly.anvils
"Not strictly relevant here, but a related note: I was very surprised
to discover, only quite recently, how handle_mm_fault() may be called
without down_read(mmap_sem) - when core dumping. That seems a
misguided optimization to me, which would also be nice to correct"
In particular because the growsdown and growsup can move the
vm_start/vm_end the various loops the core dump does around the vma will
not be consistent if page faults can happen concurrently.
Pretty much all users calling mmget_not_zero()/get_task_mm() and then
taking the mmap_sem had the potential to introduce unexpected side
effects in the core dumping code.
Adding mmap_sem for writing around the ->core_dump invocation is a
viable long term fix, but it requires removing all copy user and page
faults and to replace them with get_dump_page() for all binary formats
which is not suitable as a short term fix.
For the time being this solution manually covers the places that can
confuse the core dump either by altering the vma layout or the vma flags
while it runs. Once ->core_dump runs under mmap_sem for writing the
function mmget_still_valid() can be dropped.
Allowing mmap_sem protected sections to run in parallel with the
coredump provides some minor parallelism advantage to the swapoff code
(which seems to be safe enough by never mangling any vma field and can
keep doing swapins in parallel to the core dumping) and to some other
corner case.
In order to facilitate the backporting I added "Fixes: 86039bd3b4e6"
however the side effect of this same race condition in /proc/pid/mem
should be reproducible since before 2.6.12-rc2 so I couldn't add any
other "Fixes:" because there's no hash beyond the git genesis commit.
Because find_extend_vma() is the only location outside of the process
context that could modify the "mm" structures under mmap_sem for
reading, by adding the mmget_still_valid() check to it, all other cases
that take the mmap_sem for reading don't need the new check after
mmget_not_zero()/get_task_mm(). The expand_stack() in page fault
context also doesn't need the new check, because all tasks under core
dumping are frozen.
Link: http://lkml.kernel.org/r/20190325224949.11068-1-aarcange@redhat.com
Fixes: 86039bd3b4 ("userfaultfd: add new syscall to provide memory externalization")
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reported-by: Jann Horn <jannh@google.com>
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Jann Horn <jannh@google.com>
Acked-by: Jason Gunthorpe <jgg@mellanox.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Merge tag 'afs-fixes-20190413' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull AFS fixes from David Howells:
- Stop using the deprecated get_seconds().
- Don't make tracepoint strings const as the section they go in isn't
read-only.
- Differentiate failure due to unmarshalling from other failure cases.
We shouldn't abort with RXGEN_CC/SS_UNMARSHAL if it's not due to
unmarshalling.
- Add a missing unlock_page().
- Fix the interaction between receiving a notification from a server
that it has invalidated all outstanding callback promises and a
client call that we're in the middle of making that will get a new
promise.
* tag 'afs-fixes-20190413' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
afs: Fix in-progess ops to ignore server-level callback invalidation
afs: Unlock pages for __pagevec_release()
afs: Differentiate abort due to unmarshalling from other errors
afs: Avoid section confusion in CM_NAME
afs: avoid deprecated get_seconds()
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Merge tag '5.1-rc5-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6
Pull smb3 fixes from Steve French:
"Five small SMB3 fixes, all also for stable - an important fix for an
oplock (lease) bug, a handle leak, and three bugs spotted by KASAN"
* tag '5.1-rc5-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
CIFS: keep FileInfo handle live during oplock break
cifs: fix handle leak in smb2_query_symlink()
cifs: Fix lease buffer length error
cifs: Fix use-after-free in SMB2_read
cifs: Fix use-after-free in SMB2_write
This is a leftover from when the rings initially were not free flowing,
and hence a test for tail + 1 == head would indicate full. Since we now
let them wrap instead of mask them with the size, we need to check if
they drift more than the ring size from each other.
This fixes a case where we'd overwrite CQ ring entries, if the user
failed to reap completions. Both cases would ultimately result in lost
completions as the application violated the depth it asked for. The only
difference is that before this fix we'd return invalid entries for the
overflowed completions, instead of properly flagging it in the
cq_ring->overflow variable.
Reported-by: Stefan Bühler <source@stbuehler.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull networking fixes from David Miller:
1) Handle init flow failures properly in iwlwifi driver, from Shahar S
Matityahu.
2) mac80211 TXQs need to be unscheduled on powersave start, from Felix
Fietkau.
3) SKB memory accounting fix in A-MDSU aggregation, from Felix Fietkau.
4) Increase RCU lock hold time in mlx5 FPGA code, from Saeed Mahameed.
5) Avoid checksum complete with XDP in mlx5, also from Saeed.
6) Fix netdev feature clobbering in ibmvnic driver, from Thomas Falcon.
7) Partial sent TLS record leak fix from Jakub Kicinski.
8) Reject zero size iova range in vhost, from Jason Wang.
9) Allow pending work to complete before clcsock release from Karsten
Graul.
10) Fix XDP handling max MTU in thunderx, from Matteo Croce.
11) A lot of protocols look at the sa_family field of a sockaddr before
validating it's length is large enough, from Tetsuo Handa.
12) Don't write to free'd pointer in qede ptp error path, from Colin Ian
King.
13) Have to recompile IP options in ipv4_link_failure because it can be
invoked from ARP, from Stephen Suryaputra.
14) Doorbell handling fixes in qed from Denis Bolotin.
15) Revert net-sysfs kobject register leak fix, it causes new problems.
From Wang Hai.
16) Spectre v1 fix in ATM code, from Gustavo A. R. Silva.
17) Fix put of BROPT_VLAN_STATS_PER_PORT in bridging code, from Nikolay
Aleksandrov.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (111 commits)
socket: fix compat SO_RCVTIMEO_NEW/SO_SNDTIMEO_NEW
tcp: tcp_grow_window() needs to respect tcp_space()
ocelot: Clean up stats update deferred work
ocelot: Don't sleep in atomic context (irqs_disabled())
net: bridge: fix netlink export of vlan_stats_per_port option
qed: fix spelling mistake "faspath" -> "fastpath"
tipc: set sysctl_tipc_rmem and named_timeout right range
tipc: fix link established but not in session
net: Fix missing meta data in skb with vlan packet
net: atm: Fix potential Spectre v1 vulnerabilities
net/core: work around section mismatch warning for ptp_classifier
net: bridge: fix per-port af_packet sockets
bnx2x: fix spelling mistake "dicline" -> "decline"
route: Avoid crash from dereferencing NULL rt->from
MAINTAINERS: normalize Woojung Huh's email address
bonding: fix event handling for stacked bonds
Revert "net-sysfs: Fix memory leak in netdev_register_kobject"
rtnetlink: fix rtnl_valid_stats_req() nlmsg_len check
qed: Fix the DORQ's attentions handling
qed: Fix missing DORQ attentions
...
In the oplock break handler, writing pending changes from pages puts
the FileInfo handle. If the refcount reaches zero it closes the handle
and waits for any oplock break handler to return, thus causing a deadlock.
To prevent this situation:
* We add a wait flag to cifsFileInfo_put() to decide whether we should
wait for running/pending oplock break handlers
* We keep an additionnal reference of the SMB FileInfo handle so that
for the rest of the handler putting the handle won't close it.
- The ref is bumped everytime we queue the handler via the
cifs_queue_oplock_break() helper.
- The ref is decremented at the end of the handler
This bug was triggered by xfstest 464.
Also important fix to address the various reports of
oops in smb2_push_mandatory_locks
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
CC: Stable <stable@vger.kernel.org>
If we enter smb2_query_symlink() for something that is not a symlink
and where the SMB2_open() would succeed we would never end up
closing this handle and would thus leak a handle on the server.
Fix this by immediately calling SMB2_close() on successfull open.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
There is a KASAN slab-out-of-bounds:
BUG: KASAN: slab-out-of-bounds in _copy_from_iter_full+0x783/0xaa0
Read of size 80 at addr ffff88810c35e180 by task mount.cifs/539
CPU: 1 PID: 539 Comm: mount.cifs Not tainted 4.19 #10
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.12.0-0-ga698c8995f-prebuilt.qemu.org 04/01/2014
Call Trace:
dump_stack+0xdd/0x12a
print_address_description+0xa7/0x540
kasan_report+0x1ff/0x550
check_memory_region+0x2f1/0x310
memcpy+0x2f/0x80
_copy_from_iter_full+0x783/0xaa0
tcp_sendmsg_locked+0x1840/0x4140
tcp_sendmsg+0x37/0x60
inet_sendmsg+0x18c/0x490
sock_sendmsg+0xae/0x130
smb_send_kvec+0x29c/0x520
__smb_send_rqst+0x3ef/0xc60
smb_send_rqst+0x25a/0x2e0
compound_send_recv+0x9e8/0x2af0
cifs_send_recv+0x24/0x30
SMB2_open+0x35e/0x1620
open_shroot+0x27b/0x490
smb2_open_op_close+0x4e1/0x590
smb2_query_path_info+0x2ac/0x650
cifs_get_inode_info+0x1058/0x28f0
cifs_root_iget+0x3bb/0xf80
cifs_smb3_do_mount+0xe00/0x14c0
cifs_do_mount+0x15/0x20
mount_fs+0x5e/0x290
vfs_kern_mount+0x88/0x460
do_mount+0x398/0x31e0
ksys_mount+0xc6/0x150
__x64_sys_mount+0xea/0x190
do_syscall_64+0x122/0x590
entry_SYSCALL_64_after_hwframe+0x44/0xa9
It can be reproduced by the following step:
1. samba configured with: server max protocol = SMB2_10
2. mount -o vers=default
When parse the mount version parameter, the 'ops' and 'vals'
was setted to smb30, if negotiate result is smb21, just
update the 'ops' to smb21, but the 'vals' is still smb30.
When add lease context, the iov_base is allocated with smb21
ops, but the iov_len is initiallited with the smb30. Because
the iov_len is longer than iov_base, when send the message,
copy array out of bounds.
we need to keep the 'ops' and 'vals' consistent.
Fixes: 9764c02fcb ("SMB3: Add support for multidialect negotiate (SMB2.1 and later)")
Fixes: d5c7076b77 ("smb3: add smb3.1.1 to default dialect list")
Signed-off-by: ZhangXiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
There is a KASAN use-after-free:
BUG: KASAN: use-after-free in SMB2_read+0x1136/0x1190
Read of size 8 at addr ffff8880b4e45e50 by task ln/1009
Should not release the 'req' because it will use in the trace.
Fixes: eccb4422cf ("smb3: Add ftrace tracepoints for improved SMB3 debugging")
Signed-off-by: ZhangXiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org> 4.18+
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
There is a KASAN use-after-free:
BUG: KASAN: use-after-free in SMB2_write+0x1342/0x1580
Read of size 8 at addr ffff8880b6a8e450 by task ln/4196
Should not release the 'req' because it will use in the trace.
Fixes: eccb4422cf ("smb3: Add ftrace tracepoints for improved SMB3 debugging")
Signed-off-by: ZhangXiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org> 4.18+
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
- Avoid a crash scenario with architectures like powerpc that require
'pgtable_deposit' for the zero page.
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Merge tag 'fsdax-fix-5.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm
Pull fsdax fix from Dan Williams:
"A single filesystem-dax fix. It has been lingering in -next for a long
while and there are no other fsdax fixes on the horizon:
- Avoid a crash scenario with architectures like powerpc that require
'pgtable_deposit' for the zero page"
* tag 'fsdax-fix-5.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
fs/dax: Deposit pagetable even when installing zero page
If we have multiple threads, one doing io_uring_enter() while the other
is doing io_uring_register(), we can run into a deadlock between the
two. io_uring_register() must wait for existing users of the io_uring
instance to exit. But it does so while holding the io_uring mutex.
Callers of io_uring_enter() may need this mutex to make progress (and
eventually exit). If we wait for users to exit in io_uring_register(),
we can't do so with the io_uring mutex held without potentially risking
a deadlock.
Drop the io_uring mutex while waiting for existing callers to exit. This
is safe and guaranteed to make forward progress, since we already killed
the percpu ref before doing so. Hence later callers of io_uring_enter()
will be rejected.
Reported-by: syzbot+16dc03452dee970a0c3e@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Merge page ref overflow branch.
Jann Horn reported that he can overflow the page ref count with
sufficient memory (and a filesystem that is intentionally extremely
slow).
Admittedly it's not exactly easy. To have more than four billion
references to a page requires a minimum of 32GB of kernel memory just
for the pointers to the pages, much less any metadata to keep track of
those pointers. Jann needed a total of 140GB of memory and a specially
crafted filesystem that leaves all reads pending (in order to not ever
free the page references and just keep adding more).
Still, we have a fairly straightforward way to limit the two obvious
user-controllable sources of page references: direct-IO like page
references gotten through get_user_pages(), and the splice pipe page
duplication. So let's just do that.
* branch page-refs:
fs: prevent page refcount overflow in pipe_buf_get
mm: prevent get_user_pages() from overflowing page refcount
mm: add 'try_get_page()' helper function
mm: make page ref count overflow check tighter and more explicit
Change pipe_buf_get() to return a bool indicating whether it succeeded
in raising the refcount of the page (if the thing in the pipe is a page).
This removes another mechanism for overflowing the page refcount. All
callers converted to handle a failure.
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since the fget/fput handling was reworked in commit 09bb839434, we
never call io_file_put() with state == NULL (and hence file != NULL)
anymore. Remove that case.
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We currently call cpu_possible() even if we don't use the CPU. Move the
test under the SQ_AFF branch, which is the only place where we'll use
the value. Do the cpu_possible() test AFTER we've limited it to a max
of NR_CPUS. This avoids triggering the following warning:
WARNING: CPU: 1 PID: 7600 at include/linux/cpumask.h:121 cpu_max_bits_warn
if CONFIG_DEBUG_PER_CPU_MAPS is enabled.
While in there, also move the SQ thread idle period assignment inside
SETUP_SQPOLL, as we don't use it otherwise either.
Reported-by: syzbot+cd714a07c6de2bc34293@syzkaller.appspotmail.com
Fixes: 6c271ce2f1 ("io_uring: add submission polling")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Merge tag 'for-linus-20190412' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe:
"Set of fixes that should go into this round. This pull is larger than
I'd like at this time, but there's really no specific reason for that.
Some are fixes for issues that went into this merge window, others are
not. Anyway, this contains:
- Hardware queue limiting for virtio-blk/scsi (Dongli)
- Multi-page bvec fixes for lightnvm pblk
- Multi-bio dio error fix (Jason)
- Remove the cache hint from the io_uring tool side, since we didn't
move forward with that (me)
- Make io_uring SETUP_SQPOLL root restricted (me)
- Fix leak of page in error handling for pc requests (Jérôme)
- Fix BFQ regression introduced in this merge window (Paolo)
- Fix break logic for bio segment iteration (Ming)
- Fix NVMe cancel request error handling (Ming)
- NVMe pull request with two fixes (Christoph):
- fix the initial CSN for nvme-fc (James)
- handle log page offsets properly in the target (Keith)"
* tag 'for-linus-20190412' of git://git.kernel.dk/linux-block:
block: fix the return errno for direct IO
nvmet: fix discover log page when offsets are used
nvme-fc: correct csn initialization and increments on error
block: do not leak memory in bio_copy_user_iov()
lightnvm: pblk: fix crash in pblk_end_partial_read due to multipage bvecs
nvme: cancel request synchronously
blk-mq: introduce blk_mq_complete_request_sync()
scsi: virtio_scsi: limit number of hw queues by nr_cpu_ids
virtio-blk: limit number of hw queues by nr_cpu_ids
block, bfq: fix use after free in bfq_bfqq_expire
io_uring: restrict IORING_SETUP_SQPOLL to root
tools/io_uring: remove IOCQE_FLAG_CACHEHIT
block: don't use for-inside-for in bio_for_each_segment_all
Highlights include:
Stable fixes:
- Fix a deadlock in close() due to incorrect draining of RDMA queues
Bugfixes:
- Revert "SUNRPC: Micro-optimise when the task is known not to be sleeping"
as it is causing stack overflows
- Fix a regression where NFSv4 getacl and fs_locations stopped working
- Forbid setting AF_INET6 to "struct sockaddr_in"->sin_family.
- Fix xfstests failures due to incorrect copy_file_range() return values
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Merge tag 'nfs-for-5.1-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
Pull NFS client bugfixes from Trond Myklebust:
"Highlights include:
Stable fix:
- Fix a deadlock in close() due to incorrect draining of RDMA queues
Bugfixes:
- Revert "SUNRPC: Micro-optimise when the task is known not to be
sleeping" as it is causing stack overflows
- Fix a regression where NFSv4 getacl and fs_locations stopped
working
- Forbid setting AF_INET6 to "struct sockaddr_in"->sin_family.
- Fix xfstests failures due to incorrect copy_file_range() return
values"
* tag 'nfs-for-5.1-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
Revert "SUNRPC: Micro-optimise when the task is known not to be sleeping"
NFSv4.1 fix incorrect return value in copy_file_range
xprtrdma: Fix helper that drains the transport
NFS: Fix handling of reply page vector
NFS: Forbid setting AF_INET6 to "struct sockaddr_in"->sin_family.
The in-kernel afs filesystem client counts the number of server-level
callback invalidation events (CB.InitCallBackState* RPC operations) that it
receives from the server. This is stored in cb_s_break in various
structures, including afs_server and afs_vnode.
If an inode is examined by afs_validate(), say, the afs_server copy is
compared, along with other break counters, to those in afs_vnode, and if
one or more of the counters do not match, it is considered that the
server's callback promise is broken. At points where this happens,
AFS_VNODE_CB_PROMISED is cleared to indicate that the status must be
refetched from the server.
afs_validate() issues an FS.FetchStatus operation to get updated metadata -
and based on the updated data_version may invalidate the pagecache too.
However, the break counters are also used to determine whether to note a
new callback in the vnode (which would set the AFS_VNODE_CB_PROMISED flag)
and whether to cache the permit data included in the YFSFetchStatus record
by the server.
The problem comes when the server sends us a CB.InitCallBackState op. The
first such instance doesn't cause cb_s_break to be incremented, but rather
causes AFS_SERVER_FL_NEW to be cleared - but thereafter, say some hours
after last use and all the volumes have been automatically unmounted and
the server has forgotten about the client[*], this *will* likely cause an
increment.
[*] There are other circumstances too, such as the server restarting or
needing to make space in its callback table.
Note that the server won't send us a CB.InitCallBackState op until we talk
to it again.
So what happens is:
(1) A mount for a new volume is attempted, a inode is created for the root
vnode and vnode->cb_s_break and AFS_VNODE_CB_PROMISED aren't set
immediately, as we don't have a nominated server to talk to yet - and
we may iterate through a few to find one.
(2) Before the operation happens, afs_fetch_status(), say, notes in the
cursor (fc.cb_break) the break counter sum from the vnode, volume and
server counters, but the server->cb_s_break is currently 0.
(3) We send FS.FetchStatus to the server. The server sends us back
CB.InitCallBackState. We increment server->cb_s_break.
(4) Our FS.FetchStatus completes. The reply includes a callback record.
(5) xdr_decode_AFSCallBack()/xdr_decode_YFSCallBack() check to see whether
the callback promise was broken by checking the break counter sum from
step (2) against the current sum.
This fails because of step (3), so we don't set the callback record
and, importantly, don't set AFS_VNODE_CB_PROMISED on the vnode.
This does not preclude the syscall from progressing, and we don't loop here
rechecking the status, but rather assume it's good enough for one round
only and will need to be rechecked next time.
(6) afs_validate() it triggered on the vnode, probably called from
d_revalidate() checking the parent directory.
(7) afs_validate() notes that AFS_VNODE_CB_PROMISED isn't set, so doesn't
update vnode->cb_s_break and assumes the vnode to be invalid.
(8) afs_validate() needs to calls afs_fetch_status(). Go back to step (2)
and repeat, every time the vnode is validated.
This primarily affects volume root dir vnodes. Everything subsequent to
those inherit an already incremented cb_s_break upon mounting.
The issue is that we assume that the callback record and the cached permit
information in a reply from the server can't be trusted after getting a
server break - but this is wrong since the server makes sure things are
done in the right order, holding up our ops if necessary[*].
[*] There is an extremely unlikely scenario where a reply from before the
CB.InitCallBackState could get its delivery deferred till after - at
which point we think we have a promise when we don't. This, however,
requires unlucky mass packet loss to one call.
AFS_SERVER_FL_NEW tries to paper over the cracks for the initial mount from
a server we've never contacted before, but this should be unnecessary.
It's also further insulated from the problem on an initial mount by
querying the server first with FS.GetCapabilities, which triggers the
CB.InitCallBackState.
Fix this by
(1) Remove AFS_SERVER_FL_NEW.
(2) In afs_calc_vnode_cb_break(), don't include cb_s_break in the
calculation.
(3) In afs_cb_is_broken(), don't include cb_s_break in the check.
Signed-off-by: David Howells <dhowells@redhat.com>
__pagevec_release() complains loudly if any page in the vector is still
locked. The pages need to be locked for generic_error_remove_page(), but
that function doesn't actually unlock them.
Unlock the pages afterwards.
Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Jonathan Billings <jsbillin@umich.edu>
Differentiate an abort due to an unmarshalling error from an abort due to
other errors, such as ENETUNREACH. It doesn't make sense to set abort code
RXGEN_*_UNMARSHAL in such a case, so use RX_USER_ABORT instead.
Signed-off-by: David Howells <dhowells@redhat.com>
__tracepoint_str cannot be const because the tracepoint_str
section is not read-only. Remove the stray const.
Cc: dhowells@redhat.com
Cc: viro@zeniv.linux.org.uk
Signed-off-by: Andi Kleen <ak@linux.intel.com>
get_seconds() has a limited range on 32-bit architectures and is
deprecated because of that. While AFS uses the same limits for
its inode timestamps on the wire protocol, let's just use the
simpler current_time() as we do for other file systems.
This will still zero out the 'tv_nsec' field of the timestamps
internally.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David Howells <dhowells@redhat.com>
Check the state of the rxrpc call backing an afs call in each iteration of
the call wait loop in case the rxrpc call has already been terminated at
the rxrpc layer.
Interrupt the wait loop and mark the afs call as complete if the rxrpc
layer call is complete.
There were cases where rxrpc errors were not passed up to afs, which could
result in this loop waiting forever for an afs call to transition to
AFS_CALL_COMPLETE while the rx call was already complete.
Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Make rxrpc_kernel_check_life() pass back the life counter through the
argument list and return true if the call has not yet completed.
Suggested-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If the last bio returned is not dio->bio, the status of the bio will
not assigned to dio->bio if it is error. This will cause the whole IO
status wrong.
ksoftirqd/21-117 [021] ..s. 4017.966090: 8,0 C N 4883648 [0]
<idle>-0 [018] ..s. 4017.970888: 8,0 C WS 4924800 + 1024 [0]
<idle>-0 [018] ..s. 4017.970909: 8,0 D WS 4935424 + 1024 [<idle>]
<idle>-0 [018] ..s. 4017.970924: 8,0 D WS 4936448 + 321 [<idle>]
ksoftirqd/21-117 [021] ..s. 4017.995033: 8,0 C R 4883648 + 336 [65475]
ksoftirqd/21-117 [021] d.s. 4018.001988: myprobe1: (blkdev_bio_end_io+0x0/0x168) bi_status=7
ksoftirqd/21-117 [021] d.s. 4018.001992: myprobe: (aio_complete_rw+0x0/0x148) x0=0xffff802f2595ad80 res=0x12a000 res2=0x0
We always have to assign bio->bi_status to dio->bio.bi_status because we
will only check dio->bio.bi_status when we return the whole IO to
the upper layer.
Fixes: 542ff7bf18 ("block: new direct I/O implementation")
Cc: stable@vger.kernel.org
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Merge tag 'for-5.1-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
- fix parsing of compression algorithm when set as a inode property,
this could end up with eg. 'zst' or 'zli' in the value
- don't allow trim on a filesystem with unreplayed log, this could
cause data loss if there are pending updates to the block groups that
would not be subject to trim after replay
* tag 'for-5.1-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: prop: fix vanished compression property after failed set
btrfs: prop: fix zstd compression parameter validation
Btrfs: do not allow trimming when a fs is mounted with the nologreplay option
According to the NFSv4.2 spec if the input and output file is the
same file, operation should fail with EINVAL. However, linux
copy_file_range() system call has no such restrictions. Therefore,
in such case let's return EOPNOTSUPP and allow VFS to fallback
to doing do_splice_direct(). Also when copy_file_range is called
on an NFSv4.0 or 4.1 mount (ie., a server that doesn't support
COPY functionality), we also need to return EOPNOTSUPP and
fallback to a regular copy.
Fixes xfstest generic/075, generic/091, generic/112, generic/263
for all NFSv4.x versions.
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
NFSv4 GETACL and FS_LOCATIONS requests stopped working in v5.1-rc.
These two need the extra padding to be added directly to the reply
length.
Reported-by: Olga Kornievskaia <aglo@umich.edu>
Fixes: 02ef04e432 ("NFS: Account for XDR pad of buf->pages")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Olga Kornievskaia <aglo@umich.edu>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
syzbot is reporting uninitialized value at rpc_sockaddr2uaddr() [1]. This
is because syzbot is setting AF_INET6 to "struct sockaddr_in"->sin_family
(which is embedded into user-visible "struct nfs_mount_data" structure)
despite nfs23_validate_mount_data() cannot pass sizeof(struct sockaddr_in6)
bytes of AF_INET6 address to rpc_sockaddr2uaddr().
Since "struct nfs_mount_data" structure is user-visible, we can't change
"struct nfs_mount_data" to use "struct sockaddr_storage". Therefore,
assuming that everybody is using AF_INET family when passing address via
"struct nfs_mount_data"->addr, reject if its sin_family is not AF_INET.
[1] https://syzkaller.appspot.com/bug?id=599993614e7cbbf66bc2656a919ab2a95fb5d75c
Reported-by: syzbot <syzbot+047a11c361b872896a4f@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Pull misc fixes from Al Viro:
"A few regression fixes from this cycle"
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
aio: use kmem_cache_free() instead of kfree()
iov_iter: Fix build error without CONFIG_CRYPTO
aio: Fix an error code in __io_submit_one()
This options spawns a kernel side thread that will poll for submissions
(and completions, if IORING_SETUP_IOPOLL is set). As this allows a user
to potentially use more cycles outside of the normal hierarchy,
restrict the use of this feature to root.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Merge tag 'for-linus-20190407' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe:
- Fixups for the pf/pcd queue handling (YueHaibing)
- Revert of the three direct issue changes as they have been proven to
cause an issue with dm-mpath (Bart)
- Plug rq_count reset fix (Dongli)
- io_uring double free in fileset registration error handling (me)
- Make null_blk handle bad numa node passed in (John)
- BFQ ifdef fix (Konstantin)
- Flush queue leak fix (Shenghui)
- Plug trace fix (Yufen)
* tag 'for-linus-20190407' of git://git.kernel.dk/linux-block:
xsysace: Fix error handling in ace_setup
null_blk: prevent crash from bad home_node value
block: Revert v5.0 blk_mq_request_issue_directly() changes
paride/pcd: Fix potential NULL pointer dereference and mem leak
blk-mq: do not reset plug->rq_count before the list is sorted
paride/pf: Fix potential NULL pointer dereference
io_uring: fix double free in case of fileset regitration failure
blk-mq: add trace block plug and unplug for multiple queues
block: use blk_free_flush_queue() to free hctx->fq in blk_mq_init_hctx
block/bfq: fix ifdef for CONFIG_BFQ_GROUP_IOSCHED=y
Commit 9c225f2655 ("vfs: atomic f_pos accesses as per POSIX") added
locking for file.f_pos access and in particular made concurrent read and
write not possible - now both those functions take f_pos lock for the
whole run, and so if e.g. a read is blocked waiting for data, write will
deadlock waiting for that read to complete.
This caused regression for stream-like files where previously read and
write could run simultaneously, but after that patch could not do so
anymore. See e.g. commit 581d21a2d0 ("xenbus: fix deadlock on writes
to /proc/xen/xenbus") which fixes such regression for particular case of
/proc/xen/xenbus.
The patch that added f_pos lock in 2014 did so to guarantee POSIX thread
safety for read/write/lseek and added the locking to file descriptors of
all regular files. In 2014 that thread-safety problem was not new as it
was already discussed earlier in 2006.
However even though 2006'th version of Linus's patch was adding f_pos
locking "only for files that are marked seekable with FMODE_LSEEK (thus
avoiding the stream-like objects like pipes and sockets)", the 2014
version - the one that actually made it into the tree as 9c225f2655 -
is doing so irregardless of whether a file is seekable or not.
See
https://lore.kernel.org/lkml/53022DB1.4070805@gmail.com/https://lwn.net/Articles/180387https://lwn.net/Articles/180396
for historic context.
The reason that it did so is, probably, that there are many files that
are marked non-seekable, but e.g. their read implementation actually
depends on knowing current position to correctly handle the read. Some
examples:
kernel/power/user.c snapshot_read
fs/debugfs/file.c u32_array_read
fs/fuse/control.c fuse_conn_waiting_read + ...
drivers/hwmon/asus_atk0110.c atk_debugfs_ggrp_read
arch/s390/hypfs/inode.c hypfs_read_iter
...
Despite that, many nonseekable_open users implement read and write with
pure stream semantics - they don't depend on passed ppos at all. And for
those cases where read could wait for something inside, it creates a
situation similar to xenbus - the write could be never made to go until
read is done, and read is waiting for some, potentially external, event,
for potentially unbounded time -> deadlock.
Besides xenbus, there are 14 such places in the kernel that I've found
with semantic patch (see below):
drivers/xen/evtchn.c:667:8-24: ERROR: evtchn_fops: .read() can deadlock .write()
drivers/isdn/capi/capi.c:963:8-24: ERROR: capi_fops: .read() can deadlock .write()
drivers/input/evdev.c:527:1-17: ERROR: evdev_fops: .read() can deadlock .write()
drivers/char/pcmcia/cm4000_cs.c:1685:7-23: ERROR: cm4000_fops: .read() can deadlock .write()
net/rfkill/core.c:1146:8-24: ERROR: rfkill_fops: .read() can deadlock .write()
drivers/s390/char/fs3270.c:488:1-17: ERROR: fs3270_fops: .read() can deadlock .write()
drivers/usb/misc/ldusb.c:310:1-17: ERROR: ld_usb_fops: .read() can deadlock .write()
drivers/hid/uhid.c:635:1-17: ERROR: uhid_fops: .read() can deadlock .write()
net/batman-adv/icmp_socket.c:80:1-17: ERROR: batadv_fops: .read() can deadlock .write()
drivers/media/rc/lirc_dev.c:198:1-17: ERROR: lirc_fops: .read() can deadlock .write()
drivers/leds/uleds.c:77:1-17: ERROR: uleds_fops: .read() can deadlock .write()
drivers/input/misc/uinput.c:400:1-17: ERROR: uinput_fops: .read() can deadlock .write()
drivers/infiniband/core/user_mad.c:985:7-23: ERROR: umad_fops: .read() can deadlock .write()
drivers/gnss/core.c:45:1-17: ERROR: gnss_fops: .read() can deadlock .write()
In addition to the cases above another regression caused by f_pos
locking is that now FUSE filesystems that implement open with
FOPEN_NONSEEKABLE flag, can no longer implement bidirectional
stream-like files - for the same reason as above e.g. read can deadlock
write locking on file.f_pos in the kernel.
FUSE's FOPEN_NONSEEKABLE was added in 2008 in a7c1b990f7 ("fuse:
implement nonseekable open") to support OSSPD. OSSPD implements /dev/dsp
in userspace with FOPEN_NONSEEKABLE flag, with corresponding read and
write routines not depending on current position at all, and with both
read and write being potentially blocking operations:
See
https://github.com/libfuse/osspdhttps://lwn.net/Articles/308445https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1406https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1438-L1477https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1479-L1510
Corresponding libfuse example/test also describes FOPEN_NONSEEKABLE as
"somewhat pipe-like files ..." with read handler not using offset.
However that test implements only read without write and cannot exercise
the deadlock scenario:
https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L124-L131https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L146-L163https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L209-L216
I've actually hit the read vs write deadlock for real while implementing
my FUSE filesystem where there is /head/watch file, for which open
creates separate bidirectional socket-like stream in between filesystem
and its user with both read and write being later performed
simultaneously. And there it is semantically not easy to split the
stream into two separate read-only and write-only channels:
https://lab.nexedi.com/kirr/wendelin.core/blob/f13aa600/wcfs/wcfs.go#L88-169
Let's fix this regression. The plan is:
1. We can't change nonseekable_open to include &~FMODE_ATOMIC_POS -
doing so would break many in-kernel nonseekable_open users which
actually use ppos in read/write handlers.
2. Add stream_open() to kernel to open stream-like non-seekable file
descriptors. Read and write on such file descriptors would never use
nor change ppos. And with that property on stream-like files read and
write will be running without taking f_pos lock - i.e. read and write
could be running simultaneously.
3. With semantic patch search and convert to stream_open all in-kernel
nonseekable_open users for which read and write actually do not
depend on ppos and where there is no other methods in file_operations
which assume @offset access.
4. Add FOPEN_STREAM to fs/fuse/ and open in-kernel file-descriptors via
steam_open if that bit is present in filesystem open reply.
It was tempting to change fs/fuse/ open handler to use stream_open
instead of nonseekable_open on just FOPEN_NONSEEKABLE flags, but
grepping through Debian codesearch shows users of FOPEN_NONSEEKABLE,
and in particular GVFS which actually uses offset in its read and
write handlers
https://codesearch.debian.net/search?q=-%3Enonseekable+%3Dhttps://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1080https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1247-1346https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1399-1481
so if we would do such a change it will break a real user.
5. Add stream_open and FOPEN_STREAM handling to stable kernels starting
from v3.14+ (the kernel where 9c225f2655 first appeared).
This will allow to patch OSSPD and other FUSE filesystems that
provide stream-like files to return FOPEN_STREAM | FOPEN_NONSEEKABLE
in their open handler and this way avoid the deadlock on all kernel
versions. This should work because fs/fuse/ ignores unknown open
flags returned from a filesystem and so passing FOPEN_STREAM to a
kernel that is not aware of this flag cannot hurt. In turn the kernel
that is not aware of FOPEN_STREAM will be < v3.14 where just
FOPEN_NONSEEKABLE is sufficient to implement streams without read vs
write deadlock.
This patch adds stream_open, converts /proc/xen/xenbus to it and adds
semantic patch to automatically locate in-kernel places that are either
required to be converted due to read vs write deadlock, or that are just
safe to be converted because read and write do not use ppos and there
are no other funky methods in file_operations.
Regarding semantic patch I've verified each generated change manually -
that it is correct to convert - and each other nonseekable_open instance
left - that it is either not correct to convert there, or that it is not
converted due to current stream_open.cocci limitations.
The script also does not convert files that should be valid to convert,
but that currently have .llseek = noop_llseek or generic_file_llseek for
unknown reason despite file being opened with nonseekable_open (e.g.
drivers/input/mousedev.c)
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Yongzhi Pan <panyongzhi@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Tejun Heo <tj@kernel.org>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Nikolaus Rath <Nikolaus@rath.org>
Cc: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Kirill Smelkov <kirr@nexedi.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Trond Myklebust