Commit Graph

435 Commits

Author SHA1 Message Date
Linus Torvalds ed61a132cb Merge branch 'work.afs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull 9p fix from Al Viro:
 "Regression fix for net/9p handling of iov_iter; broken by braino when
  switching to iov_iter_is_kvec() et.al., spotted and fixed by Marc"

* 'work.afs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  iov_iter: Fix 9p virtio breakage
2018-11-03 10:35:52 -07:00
Marc Zyngier 2cbfdf4df5 iov_iter: Fix 9p virtio breakage
When switching to the new iovec accessors, a negation got subtly
dropped, leading to 9p being remarkably broken (here with kvmtool):

[    7.430941] VFS: Mounted root (9p filesystem) on device 0:15.
[    7.432080] devtmpfs: mounted
[    7.432717] Freeing unused kernel memory: 1344K
[    7.433658] Run /virt/init as init process
  Warning: unable to translate guest address 0x7e00902ff000 to host
  Warning: unable to translate guest address 0x7e00902fefc0 to host
  Warning: unable to translate guest address 0x7e00902ff000 to host
  Warning: unable to translate guest address 0x7e008febef80 to host
  Warning: unable to translate guest address 0x7e008febf000 to host
  Warning: unable to translate guest address 0x7e008febef00 to host
  Warning: unable to translate guest address 0x7e008febf000 to host
[    7.436376] Kernel panic - not syncing: Requested init /virt/init failed (error -8).
[    7.437554] CPU: 29 PID: 1 Comm: swapper/0 Not tainted 4.19.0-rc8-02267-g00e23707442a #291
[    7.439006] Hardware name: linux,dummy-virt (DT)
[    7.439902] Call trace:
[    7.440387]  dump_backtrace+0x0/0x148
[    7.441104]  show_stack+0x14/0x20
[    7.441768]  dump_stack+0x90/0xb4
[    7.442425]  panic+0x120/0x27c
[    7.443036]  kernel_init+0xa4/0x100
[    7.443725]  ret_from_fork+0x10/0x18
[    7.444444] SMP: stopping secondary CPUs
[    7.445391] Kernel Offset: disabled
[    7.446169] CPU features: 0x0,23000438
[    7.446974] Memory Limit: none
[    7.447645] ---[ end Kernel panic - not syncing: Requested init /virt/init failed (error -8). ]---

Restoring the missing "!" brings the guest back to life.

Fixes: 00e2370744 ("iov_iter: Use accessor function")
Reported-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-11-02 19:45:01 -04:00
Linus Torvalds 9931a07d51 Merge branch 'work.afs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull AFS updates from Al Viro:
 "AFS series, with some iov_iter bits included"

* 'work.afs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (26 commits)
  missing bits of "iov_iter: Separate type from direction and use accessor functions"
  afs: Probe multiple fileservers simultaneously
  afs: Fix callback handling
  afs: Eliminate the address pointer from the address list cursor
  afs: Allow dumping of server cursor on operation failure
  afs: Implement YFS support in the fs client
  afs: Expand data structure fields to support YFS
  afs: Get the target vnode in afs_rmdir() and get a callback on it
  afs: Calc callback expiry in op reply delivery
  afs: Fix FS.FetchStatus delivery from updating wrong vnode
  afs: Implement the YFS cache manager service
  afs: Remove callback details from afs_callback_break struct
  afs: Commit the status on a new file/dir/symlink
  afs: Increase to 64-bit volume ID and 96-bit vnode ID for YFS
  afs: Don't invoke the server to read data beyond EOF
  afs: Add a couple of tracepoints to log I/O errors
  afs: Handle EIO from delivery function
  afs: Fix TTL on VL server and address lists
  afs: Implement VL server rotation
  afs: Improve FS server rotation error handling
  ...
2018-11-01 19:58:52 -07:00
David Howells aa563d7bca iov_iter: Separate type from direction and use accessor functions
In the iov_iter struct, separate the iterator type from the iterator
direction and use accessor functions to access them in most places.

Convert a bunch of places to use switch-statements to access them rather
then chains of bitwise-AND statements.  This makes it easier to add further
iterator types.  Also, this can be more efficient as to implement a switch
of small contiguous integers, the compiler can use ~50% fewer compare
instructions than it has to use bitwise-and instructions.

Further, cease passing the iterator type into the iterator setup function.
The iterator function can set that itself.  Only the direction is required.

Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-24 00:41:07 +01:00
David Howells 00e2370744 iov_iter: Use accessor function
Use accessor functions to access an iterator's type and direction.  This
allows for the possibility of using some other method of determining the
type of iterator than if-chains with bitwise-AND conditions.

Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-24 00:40:44 +01:00
Dominique Martinet fb488fc1f2 9p/trans_fd: put worker reqs on destroy
p9_read_work/p9_write_work might still hold references to a req after
having been cancelled; make sure we put any of these to avoid potential
request leak on disconnect.

Fixes: 728356dede ("9p: Add refcount to p9_req_t")
Link: http://lkml.kernel.org/r/1539057956-23741-2-git-send-email-asmadeus@codewreck.org
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Reviewed-by: Tomas Bortoli <tomasbortoli@gmail.com>
2018-10-10 09:14:34 +09:00
Dominique Martinet e4ca13f7d0 9p/trans_fd: abort p9_read_work if req status changed
p9_read_work would try to handle an errored req even if it got put to
error state by another thread between the lookup (that worked) and the
time it had been fully read.
The request itself is safe to use because we hold a ref to it from the
lookup (for m->rreq, so it was safe to read into the request data buffer
until this point), but the req_list has been deleted at the same time
status changed, and client_cb already has been called as well, so we
should not do either.

Link: http://lkml.kernel.org/r/1539057956-23741-1-git-send-email-asmadeus@codewreck.org
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
Reported-by: syzbot+2222c34dc40b515f30dc@syzkaller.appspotmail.com
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Latchesar Ionkov <lucho@ionkov.net>
2018-10-10 09:13:30 +09:00
Dan Carpenter 72ea032108 9p: potential NULL dereference
p9_tag_alloc() is supposed to return error pointers, but we accidentally
return a NULL here.  It would cause a NULL dereference in the caller.

Link: http://lkml.kernel.org/m/20180926103934.GA14535@mwanda
Fixes: 996d5b4db4 ("9p: Use a slab for allocating requests")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
2018-10-10 09:13:20 +09:00
Dominique Martinet ef5305f1f7 9p: p9dirent_read: check network-provided name length
strcpy to dirent->d_name could overflow the buffer, use strscpy to check
the provided string length and error out if the size was too big.

While we are here, make the function return an error when the pdu
parsing failed, instead of returning the pdu offset as if it had been a
success...

Link: http://lkml.kernel.org/r/1536339057-21974-4-git-send-email-asmadeus@codewreck.org
Addresses-Coverity-ID: 139133 ("Copy into fixed size buffer")
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
2018-09-08 01:52:29 +09:00
Dominique Martinet 473c7dd1d7 9p/rdma: remove useless check in cm_event_handler
the client c is always dereferenced to get the rdma struct, so c has to
be a valid pointer at this point.
Gcc would optimize that away but let's make coverity happy...

Link: http://lkml.kernel.org/r/1536339057-21974-3-git-send-email-asmadeus@codewreck.org
Addresses-Coverity-ID: 102778 ("Dereference before null check")
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
2018-09-08 01:52:22 +09:00
Gertjan Halkes 2803cf4379 9p: do not trust pdu content for stat item size
v9fs_dir_readdir() could deadloop if a struct was sent with a size set
to -2

Link: http://lkml.kernel.org/r/1536134432-11997-1-git-send-email-asmadeus@codewreck.org
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=88021
Signed-off-by: Gertjan Halkes <gertjan@google.com>
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
2018-09-08 01:40:06 +09:00
Tomas Bortoli 6d35190f39 9p: Rename req to rreq in trans_fd
In struct p9_conn, rename req to rreq as it is used by the read routine.

Link: http://lkml.kernel.org/r/20180903160321.2181-1-tomasbortoli@gmail.com
Signed-off-by: Tomas Bortoli <tomasbortoli@gmail.com>
Suggested-by: Jun Piao <piaojun@huawei.com>
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
2018-09-08 01:40:04 +09:00
Dominique Martinet 8b894adb2b 9p/rdma: do not disconnect on down_interruptible EAGAIN
9p/rdma would sometimes drop the connection and display errors in
recv_done when the user does ^C.
The errors were caused by recv buffers that were posted at the time
of disconnect, and we just do not want to disconnect when
down_interruptible is... interrupted.

Link: http://lkml.kernel.org/r/1535625307-18019-1-git-send-email-asmadeus@codewreck.org
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
2018-09-08 01:39:47 +09:00
Tomas Bortoli 728356dede 9p: Add refcount to p9_req_t
To avoid use-after-free(s), use a refcount to keep track of the
usable references to any instantiated struct p9_req_t.

This commit adds p9_req_put(), p9_req_get() and p9_req_try_get() as
wrappers to kref_put(), kref_get() and kref_get_unless_zero().
These are used by the client and the transports to keep track of
valid requests' references.

p9_free_req() is added back and used as callback by kref_put().

Add SLAB_TYPESAFE_BY_RCU as it ensures that the memory freed by
kmem_cache_free() will not be reused for another type until the rcu
synchronisation period is over, so an address gotten under rcu read
lock is safe to inc_ref() without corrupting random memory while
the lock is held.

Link: http://lkml.kernel.org/r/1535626341-20693-1-git-send-email-asmadeus@codewreck.org
Co-developed-by: Dominique Martinet <dominique.martinet@cea.fr>
Signed-off-by: Tomas Bortoli <tomasbortoli@gmail.com>
Reported-by: syzbot+467050c1ce275af2a5b8@syzkaller.appspotmail.com
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
2018-09-08 01:39:47 +09:00
Tomas Bortoli 43cbcbee99 9p: rename p9_free_req() function
In sight of the next patch to add a refcount in p9_req_t, rename
the p9_free_req() function in p9_release_req().

In the next patch the actual kfree will be moved to another function.

Link: http://lkml.kernel.org/r/20180811144254.23665-1-tomasbortoli@gmail.com
Signed-off-by: Tomas Bortoli <tomasbortoli@gmail.com>
Acked-by: Jun Piao <piaojun@huawei.com>
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
2018-09-08 01:39:47 +09:00
Dominique Martinet 91a76be37f 9p: add a per-client fcall kmem_cache
Having a specific cache for the fcall allocations helps speed up
end-to-end latency.

The caches will automatically be merged if there are multiple caches
of items with the same size so we do not need to try to share a cache
between different clients of the same size.

Since the msize is negotiated with the server, only allocate the cache
after that negotiation has happened - previous allocations or
allocations of different sizes (e.g. zero-copy fcall) are made with
kmalloc directly.

Some figures on two beefy VMs with Connect-IB (sriov) / trans=rdma,
with ior running 32 processes in parallel doing small 32 bytes IOs:
 - no alloc (4.18-rc7 request cache): 65.4k req/s
 - non-power of two alloc, no patch: 61.6k req/s
 - power of two alloc, no patch: 62.2k req/s
 - non-power of two alloc, with patch: 64.7k req/s
 - power of two alloc, with patch: 65.1k req/s

Link: http://lkml.kernel.org/r/1532943263-24378-2-git-send-email-asmadeus@codewreck.org
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
Acked-by: Jun Piao <piaojun@huawei.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Greg Kurz <groug@kaod.org>
2018-09-08 01:39:47 +09:00
Dominique Martinet 523adb6cc1 9p: embed fcall in req to round down buffer allocs
'msize' is often a power of two, or at least page-aligned, so avoiding
an overhead of two dozen bytes for each allocation will help the
allocator do its work and reduce memory fragmentation.

Link: http://lkml.kernel.org/r/1533825236-22896-1-git-send-email-asmadeus@codewreck.org
Suggested-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
Reviewed-by: Greg Kurz <groug@kaod.org>
Acked-by: Jun Piao <piaojun@huawei.com>
Cc: Matthew Wilcox <willy@infradead.org>
2018-09-08 01:39:45 +09:00
Matthew Wilcox 6348b903d7 9p: Remove p9_idpool
There are no more users left of the p9_idpool; delete it.

Link: http://lkml.kernel.org/r/20180711210225.19730-7-willy@infradead.org
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@sandia.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
2018-08-29 13:39:57 +09:00
Matthew Wilcox 996d5b4db4 9p: Use a slab for allocating requests
Replace the custom batch allocation with a slab.  Use an IDR to store
pointers to the active requests instead of an array.  We don't try to
handle P9_NOTAG specially; the IDR will happily shrink all the way back
once the TVERSION call has completed.

Link: http://lkml.kernel.org/r/20180711210225.19730-6-willy@infradead.org
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@sandia.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
2018-08-29 13:39:57 +09:00
Dominique Martinet 62e3941776 9p: clear dangling pointers in p9stat_free
p9stat_free is more of a cleanup function than a 'free' function as it
only frees the content of the struct; there are chances of use-after-free
if it is improperly used (e.g. p9stat_free called twice as it used to be
possible to)

Clearing dangling pointers makes the function idempotent and safer to use.

Link: http://lkml.kernel.org/r/1535410108-20650-2-git-send-email-asmadeus@codewreck.org
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
Reported-by: syzbot+d4252148d198410b864f@syzkaller.appspotmail.com
2018-08-29 13:39:57 +09:00
Dominique Martinet 2f9ad0ac94 9p/xen: fix check for xenbus_read error in front_probe
If the xen bus exists but does not expose the proper interface, it is
possible to get a non-zero length but still some error, leading to
strcmp failing trying to load invalid memory addresses e.g.
fffffffffffffffe.

There is then no need to check length when there is no error, as the
xenbus driver guarantees that the string is nul-terminated.

Link: http://lkml.kernel.org/r/1534236007-10170-1-git-send-email-asmadeus@codewreck.org
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Latchesar Ionkov <lucho@ionkov.net>
2018-08-27 14:59:29 +09:00
Linus Torvalds 1f7a4c73a7 Merge tag '9p-for-4.19-2' of git://github.com/martinetd/linux
Pull 9p updates from Dominique Martinet:
 "This contains mostly fixes (6 to be backported to stable) and a few
  changes, here is the breakdown:

   - rework how fids are attributed by replacing some custom tracking in
     a list by an idr

   - for packet-based transports (virtio/rdma) validate that the packet
     length matches what the header says

   - a few race condition fixes found by syzkaller

   - missing argument check when NULL device is passed in sys_mount

   - a few virtio fixes

   - some spelling and style fixes"

* tag '9p-for-4.19-2' of git://github.com/martinetd/linux: (21 commits)
  net/9p/trans_virtio.c: add null terminal for mount tag
  9p/virtio: fix off-by-one error in sg list bounds check
  9p: fix whitespace issues
  9p: fix multiple NULL-pointer-dereferences
  fs/9p/xattr.c: catch the error of p9_client_clunk when setting xattr failed
  9p: validate PDU length
  net/9p/trans_fd.c: fix race by holding the lock
  net/9p/trans_fd.c: fix race-condition by flushing workqueue before the kfree()
  net/9p/virtio: Fix hard lockup in req_done
  net/9p/trans_virtio.c: fix some spell mistakes in comments
  9p/net: Fix zero-copy path in the 9p virtio transport
  9p: Embed wait_queue_head into p9_req_t
  9p: Replace the fidlist with an IDR
  9p: Change p9_fid_create calling convention
  9p: Fix comment on smp_wmb
  net/9p/client.c: version pointer uninitialized
  fs/9p/v9fs.c: fix spelling mistake "Uknown" -> "Unknown"
  net/9p: fix error path of p9_virtio_probe
  9p/net/protocol.c: return -ENOMEM when kmalloc() failed
  net/9p/client.c: add missing '\n' at the end of p9_debug()
  ...
2018-08-17 17:27:58 -07:00
Jason Gunthorpe 0a3173a5f0 Merge branch 'linus/master' into rdma.git for-next
rdma.git merge resolution for the 4.19 merge window

Conflicts:
 drivers/infiniband/core/rdma_core.c
   - Use the rdma code and revise with the new spelling for
     atomic_fetch_add_unless
 drivers/nvme/host/rdma.c
   - Replace max_sge with max_send_sge in new blk code
 drivers/nvme/target/rdma.c
   - Use the blk code and revise to use NULL for ib_post_recv when
     appropriate
   - Replace max_sge with max_recv_sge in new blk code
 net/rds/ib_send.c
   - Use the net code and revise to use NULL for ib_post_recv when
     appropriate

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-08-16 14:21:29 -06:00
Jason Gunthorpe 89982f7cce Merge tag 'v4.18' into rdma.git for-next
Resolve merge conflicts from the -rc cycle against the rdma.git tree:

Conflicts:
 drivers/infiniband/core/uverbs_cmd.c
  - New ifs added to ib_uverbs_ex_create_flow in -rc and for-next
  - Merge removal of file->ucontext in for-next with new code in -rc
 drivers/infiniband/core/uverbs_main.c
  - for-next removed code from ib_uverbs_write() that was modified
    in for-rc

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-08-16 13:12:00 -06:00
piaojun edcd9d9773 net/9p/trans_virtio.c: add null terminal for mount tag
chan->tag is Non-null terminated which will result in printing messy code
when debugging code. So we should add '\0' for tag to make the code more
convenient and robust. In addition, I drop char->tag_len to simplify the
code.

Link: http://lkml.kernel.org/r/5B641ECC.5030401@huawei.com
Signed-off-by: Jun Piao <piaojun@huawei.com>
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
2018-08-13 09:34:58 +09:00