Commit Graph

4791 Commits

Author SHA1 Message Date
Lawrence Brakmo
40304b2a15 bpf: BPF support for sock_ops
Created a new BPF program type, BPF_PROG_TYPE_SOCK_OPS, and a corresponding
struct that allows BPF programs of this type to access some of the
socket's fields (such as IP addresses, ports, etc.). It uses the
existing bpf cgroups infrastructure so the programs can be attached per
cgroup with full inheritance support. The program will be called at
appropriate times to set relevant connections parameters such as buffer
sizes, SYN and SYN-ACK RTOs, etc., based on connection information such
as IP addresses, port numbers, etc.

Alghough there are already 3 mechanisms to set parameters (sysctls,
route metrics and setsockopts), this new mechanism provides some
distinct advantages. Unlike sysctls, it can set parameters per
connection. In contrast to route metrics, it can also use port numbers
and information provided by a user level program. In addition, it could
set parameters probabilistically for evaluation purposes (i.e. do
something different on 10% of the flows and compare results with the
other 90% of the flows). Also, in cases where IPv6 addresses contain
geographic information, the rules to make changes based on the distance
(or RTT) between the hosts are much easier than route metric rules and
can be global. Finally, unlike setsockopt, it oes not require
application changes and it can be updated easily at any time.

Although the bpf cgroup framework already contains a sock related
program type (BPF_PROG_TYPE_CGROUP_SOCK), I created the new type
(BPF_PROG_TYPE_SOCK_OPS) beccause the existing type expects to be called
only once during the connections's lifetime. In contrast, the new
program type will be called multiple times from different places in the
network stack code.  For example, before sending SYN and SYN-ACKs to set
an appropriate timeout, when the connection is established to set
congestion control, etc. As a result it has "op" field to specify the
type of operation requested.

The purpose of this new program type is to simplify setting connection
parameters, such as buffer sizes, TCP's SYN RTO, etc. For example, it is
easy to use facebook's internal IPv6 addresses to determine if both hosts
of a connection are in the same datacenter. Therefore, it is easy to
write a BPF program to choose a small SYN RTO value when both hosts are
in the same datacenter.

This patch only contains the framework to support the new BPF program
type, following patches add the functionality to set various connection
parameters.

This patch defines a new BPF program type: BPF_PROG_TYPE_SOCKET_OPS
and a new bpf syscall command to load a new program of this type:
BPF_PROG_LOAD_SOCKET_OPS.

Two new corresponding structs (one for the kernel one for the user/BPF
program):

/* kernel version */
struct bpf_sock_ops_kern {
        struct sock *sk;
        __u32  op;
        union {
                __u32 reply;
                __u32 replylong[4];
        };
};

/* user version
 * Some fields are in network byte order reflecting the sock struct
 * Use the bpf_ntohl helper macro in samples/bpf/bpf_endian.h to
 * convert them to host byte order.
 */
struct bpf_sock_ops {
        __u32 op;
        union {
                __u32 reply;
                __u32 replylong[4];
        };
        __u32 family;
        __u32 remote_ip4;     /* In network byte order */
        __u32 local_ip4;      /* In network byte order */
        __u32 remote_ip6[4];  /* In network byte order */
        __u32 local_ip6[4];   /* In network byte order */
        __u32 remote_port;    /* In network byte order */
        __u32 local_port;     /* In host byte horder */
};

Currently there are two types of ops. The first type expects the BPF
program to return a value which is then used by the caller (or a
negative value to indicate the operation is not supported). The second
type expects state changes to be done by the BPF program, for example
through a setsockopt BPF helper function, and they ignore the return
value.

The reply fields of the bpf_sockt_ops struct are there in case a bpf
program needs to return a value larger than an integer.

Signed-off-by: Lawrence Brakmo <brakmo@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-01 16:15:13 -07:00
Neil Horman
2cb5c8e378 sctp: Add peeloff-flags socket option
Based on a request raised on the sctp devel list, there is a need to
augment the sctp_peeloff operation while specifying the O_CLOEXEC and
O_NONBLOCK flags (simmilar to the socket syscall).  Since modifying the
SCTP_SOCKOPT_PEELOFF socket option would break user space ABI for existing
programs, this patch creates a new socket option
SCTP_SOCKOPT_PEELOFF_FLAGS, which accepts a third flags parameter to
allow atomic assignment of the socket descriptor flags.

Tested successfully by myself and the requestor

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: Vlad Yasevich <vyasevich@gmail.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: Andreas Steinmetz <ast@domdv.de>
CC: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-01 15:26:11 -07:00
Jerry Hoemann
759d6a9641 libnvdimm: New ACPI 6.2 DSM functions
ACPI 6.2 added new NVDIMM root DSM functions.  Define their
data structures.

Signed-off-by: Jerry Hoemann <jerry.hoemann@hpe.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-07-01 08:49:59 -07:00
Jerry Hoemann
37d74841b9 acpi, nfit: Enable DSM pass thru for root functions.
Set ND_CMD_CALL in the cmd_mask to enable calling root
functions via the pass thru mechanism.

Signed-off-by: Jerry Hoemann <jerry.hoemann@hpe.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-07-01 08:49:59 -07:00
Zack Weinberg
fbd576295d uapi/linux/a.out.h: don't use deprecated system-specific predefines.
uapi/linux/a.out.h uses a number of predefined macros that are
deprecated because they're in the application namespace
(e.g. '#ifdef linux' instead of '#ifdef __linux__').
This patch either corrects or just removes them if they are not
applicable to Linux.

The primary reason this is worth bothering to fix, considering how
obsolete a.out binary support is, is that the GCC build process
considers this such a severe error that it will copy the header into a
private directory and change the macro names, which causes future
updates to the header to be masked.  This header probably doesn't get
updated very often anymore, but it is the _only_ uapi header that gets
this treatment, so IMHO it is worth patching just to drive that number
all the way to zero.

Signed-off-by: Zack Weinberg <zackw@panix.com>
[hch: removed dead conditionals]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-06-30 13:53:07 -07:00
Andrei Otcheretianski
36a554cec1 nl80211: Don't verify owner_nlportid on NAN commands
If NAN interface is created with NL80211_ATTR_SOCKET_OWNER, the socket
that is used to create the interface is used for all NAN operations and
reporting NAN events.
However, it turns out that sending commands and receiving events on
the same socket is not possible in a completely race-free way:
If the socket buffer is overflowed by the events, the command response
will not be sent. In that case the caller will block forever on recv.
Using non-blocking socket for commands is more complicated and still
the command response or ack may not be received.
So, keep unicasting NAN events to the interface creator, but allow
using a different socket for commands.

Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
2017-06-30 09:44:17 +03:00
Logan Gunthorpe
079e3bc588 switchtec: Add "running" status flag to fw partition info ioctl
This flag lets userspace know which firmware partitions are currently in
use as opposed to just active.  "Active" means they will be in use for the
next reboot, whereas "running" means they are currently in use.

If an old kernel is in use, or the firmware doesn't support these fields,
the new flag will not be set in the output.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Kurt Schwemmer <kurt.schwemmer@microsemi.com>
2017-06-27 18:23:14 -05:00
Jens Axboe
c75b1d9421 fs: add fcntl() interface for setting/getting write life time hints
Define a set of write life time hints:

RWH_WRITE_LIFE_NOT_SET	No hint information set
RWH_WRITE_LIFE_NONE	No hints about write life time
RWH_WRITE_LIFE_SHORT	Data written has a short life time
RWH_WRITE_LIFE_MEDIUM	Data written has a medium life time
RWH_WRITE_LIFE_LONG	Data written has a long life time
RWH_WRITE_LIFE_EXTREME	Data written has an extremely long life time

The intent is for these values to be relative to each other, no
absolute meaning should be attached to these flag names.

Add an fcntl interface for querying these flags, and also for
setting them as well:

F_GET_RW_HINT		Returns the read/write hint set on the
			underlying inode.

F_SET_RW_HINT		Set one of the above write hints on the
			underlying inode.

F_GET_FILE_RW_HINT	Returns the read/write hint set on the
			file descriptor.

F_SET_FILE_RW_HINT	Set one of the above write hints on the
			file descriptor.

The user passes in a 64-bit pointer to get/set these values, and
the interface returns 0/-1 on success/error.

Sample program testing/implementing basic setting/getting of write
hints is below.

Add support for storing the write life time hint in the inode flags
and in struct file as well, and pass them to the kiocb flags. If
both a file and its corresponding inode has a write hint, then we
use the one in the file, if available. The file hint can be used
for sync/direct IO, for buffered writeback only the inode hint
is available.

This is in preparation for utilizing these hints in the block layer,
to guide on-media data placement.

/*
 * writehint.c: get or set an inode write hint
 */
 #include <stdio.h>
 #include <fcntl.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <stdbool.h>
 #include <inttypes.h>

 #ifndef F_GET_RW_HINT
 #define F_LINUX_SPECIFIC_BASE	1024
 #define F_GET_RW_HINT		(F_LINUX_SPECIFIC_BASE + 11)
 #define F_SET_RW_HINT		(F_LINUX_SPECIFIC_BASE + 12)
 #endif

static char *str[] = { "RWF_WRITE_LIFE_NOT_SET", "RWH_WRITE_LIFE_NONE",
			"RWH_WRITE_LIFE_SHORT", "RWH_WRITE_LIFE_MEDIUM",
			"RWH_WRITE_LIFE_LONG", "RWH_WRITE_LIFE_EXTREME" };

int main(int argc, char *argv[])
{
	uint64_t hint;
	int fd, ret;

	if (argc < 2) {
		fprintf(stderr, "%s: file <hint>\n", argv[0]);
		return 1;
	}

	fd = open(argv[1], O_RDONLY);
	if (fd < 0) {
		perror("open");
		return 2;
	}

	if (argc > 2) {
		hint = atoi(argv[2]);
		ret = fcntl(fd, F_SET_RW_HINT, &hint);
		if (ret < 0) {
			perror("fcntl: F_SET_RW_HINT");
			return 4;
		}
	}

	ret = fcntl(fd, F_GET_RW_HINT, &hint);
	if (ret < 0) {
		perror("fcntl: F_GET_RW_HINT");
		return 3;
	}

	printf("%s: hint %s\n", argv[1], str[hint]);
	close(fd);
	return 0;
}

Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-27 12:05:22 -06:00
David S. Miller
24a72b77f3 Merge tag 'wireless-drivers-next-for-davem-2017-06-25' of git://git.kernel.org/pub/scm/linux/kernel/git/kvalo/wireless-drivers-next
Kalle Valo says:

====================
wireless-drivers-next patches for 4.13

New features and bug fixes to quite a few different drivers, but
nothing really special standing out.

What makes me happy that we have now more vendors actively
contributing to upstream drivers. In this pull request we have patches
from Broadcom, Intel, Qualcomm, Realtek and Redpine Signals, and I
still have patches from Marvell and Quantenna pending in patchwork. Now
that's something comparing to how things looked 11 years ago in Jeff
Garzik's "State of the Union: Wireless" email:

https://lkml.org/lkml/2006/1/5/671

Major changes:

wil6210

* add low level RF sector interface via nl80211 vendor commands

* add module parameter ftm_mode to load separate firmware for factory
  testing

* support devices with different PCIe bar size

* add support for PCIe D3hot in system suspend

* remove ioctl interface which should not be in a wireless driver

ath10k

* go back to using dma_alloc_coherent() for firmware scratch memory

* add per chain RSSI reporting

brcmfmac

* add support multi-scheduled scan

* add scheduled scan support for specified BSSIDs

* add support for brcm43430 revision 0

wlcore

* add wil1285 compatible

rsi

* add RS9113 USB support

iwlwifi

* FW API documentation improvements (for tools and htmldoc)

* continuing work for the new A000 family

* bump the maximum supported FW API to 31

* improve the differentiation between 8000, 9000 and A000 families
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-25 14:45:34 -04:00
Daniel Walter
b7e7cf7a66 fscrypt: add support for AES-128-CBC
fscrypt provides facilities to use different encryption algorithms which
are selectable by userspace when setting the encryption policy. Currently,
only AES-256-XTS for file contents and AES-256-CBC-CTS for file names are
implemented. This is a clear case of kernel offers the mechanism and
userspace selects a policy. Similar to what dm-crypt and ecryptfs have.

This patch adds support for using AES-128-CBC for file contents and
AES-128-CBC-CTS for file name encryption. To mitigate watermarking
attacks, IVs are generated using the ESSIV algorithm. While AES-CBC is
actually slightly less secure than AES-XTS from a security point of view,
there is more widespread hardware support. Using AES-CBC gives us the
acceptable performance while still providing a moderate level of security
for persistent storage.

Especially low-powered embedded devices with crypto accelerators such as
CAAM or CESA often only support AES-CBC. Since using AES-CBC over AES-XTS
is basically thought of a last resort, we use AES-128-CBC over AES-256-CBC
since it has less encryption rounds and yields noticeable better
performance starting from a file size of just a few kB.

Signed-off-by: Daniel Walter <dwalter@sigma-star.at>
[david@sigma-star.at: addressed review comments]
Signed-off-by: David Gstir <david@sigma-star.at>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-23 20:05:07 -04:00
Jakub Kicinski
ce158e580a xdp: add reporting of offload mode
Extend the XDP_ATTACHED_* values to include offloaded mode.
Let drivers report whether program is installed in the driver
or the HW by changing the prog_attached field from bool to
u8 (type of the netlink attribute).

Exploit the fact that the value of XDP_ATTACHED_DRV is 1,
therefore since all drivers currently assign the mode with
double negation:
       mode = !!xdp_prog;
no drivers have to be modified.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-23 13:42:20 -04:00
Jakub Kicinski
ee5d032f7d xdp: add HW offload mode flag for installing programs
Add an installation-time flag for requesting that the program
be installed only if it can be offloaded to HW.

Internally new command for ndo_xdp is added, this way we avoid
putting checks into drivers since they all return -EINVAL on
an unknown command.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-23 13:42:19 -04:00
Kalle Valo
52f8c9380f Merge ath-next from git://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git
ath.git patches for 4.13. Major changes:

wil6210

* add low level RF sector interface via nl80211 vendor commands

* add module parameter ftm_mode to load separate firmware for factory
  testing

* support devices with different PCIe bar size

* add support for PCIe D3hot in system suspend

* remove ioctl interface which should not be in a wireless driver

ath10k

* go back to using dma_alloc_coherent() for firmware scratch memory

* add per chain RSSI reporting
2017-06-22 16:29:52 +03:00
Claudio Imbrenda
4036e3874a KVM: s390: ioctls to get and set guest storage attributes
* Add the struct used in the ioctls to get and set CMMA attributes.
* Add the two functions needed to get and set the CMMA attributes for
  guest pages.
* Add the two ioctls that use the aforementioned functions.

Signed-off-by: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2017-06-22 12:41:06 +02:00
Paul Mackerras
2ed4f9dd19 KVM: PPC: Book3S HV: Add capability to report possible virtual SMT modes
Now that userspace can set the virtual SMT mode by enabling the
KVM_CAP_PPC_SMT capability, it is useful for userspace to be able
to query the set of possible virtual SMT modes.  This provides a
new capability, KVM_CAP_PPC_SMT_POSSIBLE, to provide this
information.  The return value is a bitmap of possible modes, with
bit N set if virtual SMT mode 2^N is available.  That is, 1 indicates
SMT1 is available, 2 indicates that SMT2 is available, 3 indicates
that both SMT1 and SMT2 are available, and so on.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-06-22 11:25:31 +10:00
Daniel Borkmann
e86283071f bpf: expose prog id for cls_bpf and act_bpf
In order to be able to retrieve the attached programs from cls_bpf
and act_bpf, we need to expose the prog ids via netlink so that
an application can later on get an fd based on the id through the
BPF_PROG_GET_FD_BY_ID command, and dump related prog info via
BPF_OBJ_GET_INFO_BY_FD command for bpf(2).

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-21 15:14:23 -04:00
Julien Gomes
dd12d15c9a ip6mr: add netlink notifications on mrt6msg cache reports
Add Netlink notifications on cache reports in ip6mr, in addition to the
existing mrt6msg sent to mroute6_sk.
Send RTM_NEWCACHEREPORT notifications to RTNLGRP_IPV6_MROUTE_R.

MSGTYPE, MIF_ID, SRC_ADDR and DST_ADDR Netlink attributes contain the
same data as their equivalent fields in the mrt6msg header.
PKT attribute is the packet sent to mroute6_sk, without the added
mrt6msg header.

Suggested-by: Ryan Halbrook <halbrook@arista.com>
Signed-off-by: Julien Gomes <julien@arista.com>
Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-21 11:22:53 -04:00
Julien Gomes
5a645dd86c ipmr: add netlink notifications on igmpmsg cache reports
Add Netlink notifications on cache reports in ipmr, in addition to the
existing igmpmsg sent to mroute_sk.
Send RTM_NEWCACHEREPORT notifications to RTNLGRP_IPV4_MROUTE_R.

MSGTYPE, VIF_ID, SRC_ADDR and DST_ADDR Netlink attributes contain the
same data as their equivalent fields in the igmpmsg header.
PKT attribute is the packet sent to mroute_sk, without the added igmpmsg
header.

Suggested-by: Ryan Halbrook <halbrook@arista.com>
Signed-off-by: Julien Gomes <julien@arista.com>
Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-21 11:22:52 -04:00
Julien Gomes
5f729eaabe rtnetlink: add restricted rtnl groups for ipv4 and ipv6 mroute
Add RTNLGRP_{IPV4,IPV6}_MROUTE_R as two new restricted groups for the
NETLINK_ROUTE family.
Binding to these groups specifically requires CAP_NET_ADMIN to allow
multicast of sensitive messages (e.g. mroute cache reports).

Suggested-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Julien Gomes <julien@arista.com>
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-21 11:22:52 -04:00
Julien Gomes
94df30a652 rtnetlink: add NEWCACHEREPORT message type
New NEWCACHEREPORT message type to be used for cache reports sent
via Netlink, effectively allowing splitting cache report reception from
mroute programming.

Suggested-by: Ryan Halbrook <halbrook@arista.com>
Signed-off-by: Julien Gomes <julien@arista.com>
Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-21 11:22:52 -04:00
Maya Erez
a520b49ec1 wil6210: remove ioctl interface
Wireless drivers should not be using ioctl interface,
hence remove this interface for wil6210 driver.

Signed-off-by: Maya Erez <qca_merez@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
2017-06-21 16:18:51 +03:00
Thomas Gleixner
f0cd9ae5d0 Merge branch 'timers/urgent' into timers/core
Pick up dependent changes.
2017-06-21 09:07:52 +02:00
Aravinda Prasad
134764ed6e KVM: PPC: Book3S HV: Add new capability to control MCE behaviour
This introduces a new KVM capability to control how KVM behaves
on machine check exception (MCE) in HV KVM guests.

If this capability has not been enabled, KVM redirects machine check
exceptions to guest's 0x200 vector, if the address in error belongs to
the guest. With this capability enabled, KVM will cause a guest exit
with the exit reason indicating an NMI.

The new capability is required to avoid problems if a new kernel/KVM
is used with an old QEMU, running a guest that doesn't issue
"ibm,nmi-register".  As old QEMU does not understand the NMI exit
type, it treats it as a fatal error.  However, the guest could have
handled the machine check error if the exception was delivered to
guest's 0x200 interrupt vector instead of NMI exit in case of old
QEMU.

[paulus@ozlabs.org - Reworded the commit message to be clearer,
 enable only on HV KVM.]

Signed-off-by: Aravinda Prasad <aravinda@linux.vnet.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-06-21 13:37:08 +10:00
Arnd Bergmann
d320695add [media] dvb: don't use 'time_t' in event ioctl
'struct video_event' is used for the VIDEO_GET_EVENT ioctl, implemented
by drivers/media/pci/ivtv/ivtv-ioctl.c and
drivers/media/pci/ttpci/av7110_av.c. The structure contains a 'time_t',
which will be redefined in the future to be 64-bit wide, causing an
incompatible ABI change for this ioctl.

As it turns out, neither of the drivers currently sets the timestamp
field, and it is presumably useless anyway because of the limited
resolutions (no sub-second times). This means we can simply change
the structure definition to use a 'long' instead of 'time_t' and
remain compatible with all existing user space binaries when time_t
gets changed.

If anybody ever starts using this field, they have to make sure not
to use 1970 based seconds in there, as those overflow in 2038.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-06-20 11:27:01 -03:00
Goldwyn Rodrigues
b745fafaf7 fs: Introduce RWF_NOWAIT and FMODE_AIO_NOWAIT
RWF_NOWAIT informs kernel to bail out if an AIO request will block
for reasons such as file allocations, or a writeback triggered,
or would block while allocating requests while performing
direct I/O.

RWF_NOWAIT is translated to IOCB_NOWAIT for iocb->ki_flags.

FMODE_AIO_NOWAIT is a flag which identifies the file opened is capable
of returning -EAGAIN if the AIO call will block. This must be set by
supporting filesystems in the ->open() call.

Filesystems xfs, btrfs and ext4 would be supported in the following patches.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-20 07:12:03 -06:00