[ Upstream commit c576e0fcd6188d0edb50b0fb83f853433ef4819b ]
With the idea of returning pidfds from the fanotify API, we need to
expose a mechanism for creating pidfds. We drop the static qualifier
from pidfd_create() and add its declaration to linux/pid.h so that the
pidfd_create() helper can be called from other kernel subsystems
i.e. fanotify.
Link: https://lore.kernel.org/r/0c68653ec32f1b7143301f0231f7ed14062fd82b.1628398044.git.repnop@google.com
Signed-off-by: Matthew Bobrowski <repnop@google.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f4e44b393389c77958f7c58bf4415032b4cda15b ]
Currently the source's export is mounted and unmounted on every
inter-server copy operation. This patch is an enhancement to delay
the unmount of the source export for a certain period of time to
eliminate the mount and unmount overhead on subsequent copy operations.
After a copy operation completes, a work entry is added to the
delayed unmount list with an expiration time. This list is serviced
by the laundromat thread to unmount the export of the expired entries.
Each time the export is being used again, its expiration time is
extended and the entry is re-inserted to the tail of the list.
The unmount task and the mount operation of the copy request are
synced to make sure the export is not unmounted while it's being
used.
Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a8b98c808eab3ec8f1b5a64be967b0f4af4cae43 ]
Reporting event->pid should depend on the privileges of the user that
initialized the group, not the privileges of the user reading the
events.
Use an internal group flag FANOTIFY_UNPRIV to record the fact that the
group was initialized by an unprivileged user.
To be on the safe side, the premissions to setup filesystem and mount
marks now require that both the user that initialized the group and
the user setting up the mark have CAP_SYS_ADMIN.
Link: https://lore.kernel.org/linux-fsdevel/CAOQ4uxiA77_P5vtv7e83g0+9d7B5W9ZTE4GfQEYbWmfT1rA=VA@mail.gmail.com/
Fixes: 7cea2a3c505e ("fanotify: support limited functionality for unprivileged users")
Cc: <Stable@vger.kernel.org> # v5.12+
Link: https://lore.kernel.org/r/20210524135321.2190062-1-amir73il@gmail.com
Reviewed-by: Matthew Bobrowski <repnop@google.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7cea2a3c505e87a9d6afc78be4a7f7be636a73a7 ]
Add limited support for unprivileged fanotify groups.
An unprivileged users is not allowed to get an open file descriptor in
the event nor the process pid of another process. An unprivileged user
cannot request permission events, cannot set mount/filesystem marks and
cannot request unlimited queue/marks.
This enables the limited functionality similar to inotify when watching a
set of files and directories for OPEN/ACCESS/MODIFY/CLOSE events, without
requiring SYS_CAP_ADMIN privileges.
The FAN_REPORT_DFID_NAME init flag, provide a method for an unprivileged
listener watching a set of directories (with FAN_EVENT_ON_CHILD) to monitor
all changes inside those directories.
This typically requires that the listener keeps a map of watched directory
fid to dirfd (O_PATH), where fid is obtained with name_to_handle_at()
before starting to watch for changes.
When getting an event, the reported fid of the parent should be resolved
to dirfd and fstatsat(2) with dirfd and name should be used to query the
state of the filesystem entry.
Link: https://lore.kernel.org/r/20210304112921.3996419-3-amir73il@gmail.com
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5b8fea65d197f408bb00b251c70d842826d6b70b ]
fanotify has some hardcoded limits. The only APIs to escape those limits
are FAN_UNLIMITED_QUEUE and FAN_UNLIMITED_MARKS.
Allow finer grained tuning of the system limits via sysfs tunables under
/proc/sys/fs/fanotify, similar to tunables under /proc/sys/fs/inotify,
with some minor differences.
- max_queued_events - global system tunable for group queue size limit.
Like the inotify tunable with the same name, it defaults to 16384 and
applies on initialization of a new group.
- max_user_marks - user ns tunable for marks limit per user.
Like the inotify tunable named max_user_watches, on a machine with
sufficient RAM and it defaults to 1048576 in init userns and can be
further limited per containing user ns.
- max_user_groups - user ns tunable for number of groups per user.
Like the inotify tunable named max_user_instances, it defaults to 128
in init userns and can be further limited per containing user ns.
The slightly different tunable names used for fanotify are derived from
the "group" and "mark" terminology used in the fanotify man pages and
throughout the code.
Considering the fact that the default value for max_user_instances was
increased in kernel v5.10 from 8192 to 1048576, leaving the legacy
fanotify limit of 8192 marks per group in addition to the max_user_marks
limit makes little sense, so the per group marks limit has been removed.
Note that when a group is initialized with FAN_UNLIMITED_MARKS, its own
marks are not accounted in the per user marks account, so in effect the
limit of max_user_marks is only for the collection of groups that are
not initialized with FAN_UNLIMITED_MARKS.
Link: https://lore.kernel.org/r/20210304112921.3996419-2-amir73il@gmail.com
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 94e00d28a680dff18805ca472b191364347d2234 ]
In order to improve event merge performance, hash events in a 128 size
hash table by the event merge key.
The fanotify_event size grows by two pointers, but we just reduced its
size by removing the objectid member, so overall its size is increased
by one pointer.
Permission events and overflow event are not merged so they are also
not hashed.
Link: https://lore.kernel.org/r/20210304104826.3993892-5-amir73il@gmail.com
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 8988f11abb820bacfcc53d498370bfb30f792ec4 ]
objectid is only used by fanotify backend and it is just an optimization
for event merge before comparing all fields in event.
Move the objectid member from common struct fsnotify_event into struct
fanotify_event and reduce it to 29-bit hash to cram it together with the
3-bit event type.
Events of different types are never merged, so the combination of event
type and hash form a 32-bit key for fast compare of events.
This reduces the size of events by one pointer and paves the way for
adding hashed queue support for fanotify.
Link: https://lore.kernel.org/r/20210304104826.3993892-3-amir73il@gmail.com
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6f73171e192366ff7c98af9fb50615ef9615f8a7 ]
Current code has an assumtion that fsnotify_notify_queue_is_empty() is
called to verify that queue is not empty before trying to peek or remove
an event from queue.
Remove this assumption by moving the fsnotify_notify_queue_is_empty()
into the functions, allow them to return NULL value and check return
value by all callers.
This is a prep patch for multi event queues.
Link: https://lore.kernel.org/r/20210304104826.3993892-2-amir73il@gmail.com
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7dcfbd86adc45f6d6b37278efd22530cf80ab474 ]
Prepare svc_xprt_received() to be called from transport code instead
of from generic RPC server code.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit bddfdbcddbe267519cd36aeb115fdf8620980111 ]
NFSD initializes an encode xdr_stream only after the RPC layer has
already inserted the RPC Reply header. Thus it behaves differently
than xdr_init_encode does, which assumes the passed-in xdr_buf is
entirely devoid of content.
nfs4proc.c has this server-side stream initialization helper, but
it is visible only to the NFSv4 code. Move this helper to a place
that can be accessed by NFSv2 and NFSv3 server XDR functions.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9fe61450972d3900bffb1dc26a17ebb9cdd92db2 ]
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>
[ cel: backported to 5.10.y, prior to idmapped mounts ]
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 02f92b3868a1b34ab98464e76b0e4e060474ba10 ]
Add two simple helpers to check permissions on a file and path
respectively and convert over some callers. It simplifies quite a few
codepaths and also reduces the churn in later patches quite a bit.
Christoph also correctly points out that this makes codepaths (e.g.
ioctls) way easier to follow that would otherwise have to do more
complex argument passing than necessary.
Link: https://lore.kernel.org/r/20210121131959.646623-4-christian.brauner@ubuntu.com
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Suggested-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 3e3552056ab42f883d7723eeb42fed712b66bacf ]
kallsyms_on_each_symbol and module_kallsyms_on_each_symbol are only used
by the livepatching code, so don't build them if livepatching is not
enabled.
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a006050575745ca2be25118b90f1c37f454ac542 ]
Allow for a RCU-sched critical section around find_module, following
the lower level find_module_all helper, and switch the two callers
outside of module.c to use such a RCU-sched critical section instead
of module_mutex.
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ac7b79fd190b02e7151bc7d2b9da692f537657f3 ]
Currently the fs sysctl inotify/max_user_instances is used to limit the
number of inotify instances on the system. For systems running multiple
workloads, the per-user namespace sysctl max_inotify_instances can be
used to further partition inotify instances. However there is no easy
way to set a sensible system level max limit on inotify instances and
further partition it between the workloads. It is much easier to charge
the underlying resource (i.e. memory) behind the inotify instances to
the memcg of the workload and let their memory limits limit the number
of inotify instances they can create.
With inotify instances charged to memcg, the admin can simply set
max_user_instances to INT_MAX and let the memcg limits of the jobs limit
their inotify instances.
Link: https://lore.kernel.org/r/20201220044608.1258123-1-shakeelb@google.com
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 3cc55f4434b421d37300aa9a167ace7d60b45ccf ]
When exporting NFS, we may as well use the real change attribute
returned by the original server instead of faking up a change attribute
from the ctime.
Note we can't do that by setting I_VERSION--that would also turn on the
logic in iversion.h which treats the lower bit specially, and that
doesn't make sense for NFS.
So instead we define a new export operation for filesystems like NFS
that want to manage the change attribute themselves.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 81d217474326b25d7f14274b02fe3da1e85ad934 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 2289e87b5951f97783f07fc895e6c5e804b53668 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 8760c909f54a82aaa6e76da19afe798a0c77c3c3 ]
The function __close_fd was added to support binder[1]. Now that
binder has been fixed to no longer need __close_fd[2] all calls
to __close_fd pass current->files.
Therefore transform the files parameter into a local variable
initialized to current->files, and rename __close_fd to close_fd to
reflect this change, and keep it in sync with the similar changes to
__alloc_fd, and __fd_install.
This removes the need for callers to care about the extra care that
needs to be take if anything except current->files is passed, by
limiting the callers to only operation on current->files.
[1] 483ce1d4b8c3 ("take descriptor-related part of close() to file.c")
[2] 44d8047f1d87 ("binder: use standard functions to allocate fds")
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
v1: https://lkml.kernel.org/r/20200817220425.9389-17-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20201120231441.29911-21-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit aa384d10f3d06d4b85597ff5df41551262220e16 ]
The function __alloc_fd was added to support binder[1]. With binder
fixed[2] there are no more users.
As alloc_fd just calls __alloc_fd with "files=current->files",
merge them together by transforming the files parameter into a
local variable initialized to current->files.
[1] dcfadfa4ec5a ("new helper: __alloc_fd()")
[2] 44d8047f1d87 ("binder: use standard functions to allocate fds")
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
v1: https://lkml.kernel.org/r/20200817220425.9389-16-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20201120231441.29911-20-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d74ba04d919ebe30bf47406819c18c6b50003d92 ]
The function __fd_install was added to support binder[1]. With binder
fixed[2] there are no more users.
As fd_install just calls __fd_install with "files=current->files",
merge them together by transforming the files parameter into a
local variable initialized to current->files.
[1] f869e8a7f753 ("expose a low-level variant of fd_install() for binder")
[2] 44d8047f1d87 ("binder: use standard functions to allocate fds")
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
v1: https://lkml.kernel.org/r/20200817220425.9389-14-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20201120231441.29911-18-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e9a53aeb5e0a838f10fcea74235664e7ad5e6e1a ]
As a companion to fget_task and task_lookup_fd_rcu implement
task_lookup_next_fd_rcu that will return the struct file for the first
file descriptor number that is equal or greater than the fd argument
value, or NULL if there is no such struct file.
This allows file descriptors of foreign processes to be iterated
through safely, without needed to increment the count on files_struct.
Some concern[1] has been expressed that this function takes the task_lock
for each iteration and thus for each file descriptor. This place
where this function will be called in a commonly used code path is for
listing /proc/<pid>/fd. I did some small benchmarks and did not see
any measurable performance differences. For ordinary users ls is
likely to stat each of the directory entries and tid_fd_mode called
from tid_fd_revalidae has always taken the task lock for each file
descriptor. So this does not look like it will be a big change in
practice.
At some point is will probably be worth changing put_files_struct to
free files_struct after an rcu grace period so that task_lock won't be
needed at all.
[1] https://lkml.kernel.org/r/20200817220425.9389-10-ebiederm@xmission.com
v1: https://lkml.kernel.org/r/20200817220425.9389-9-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20201120231441.29911-14-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 460b4f812a9d473d4b39d87d37844f9fc30a9eb3 ]
Also remove the confusing comment about checking if a fd exists. I
could not find one instance in the entire kernel that still matches
the description or the reason for the name fcheck.
The need for better names became apparent in the last round of
discussion of this set of changes[1].
[1] https://lkml.kernel.org/r/CAHk-=wj8BQbgJFLa+J0e=iT-1qpmCRTbPAJ8gd6MJQ=kbRPqyQ@mail.gmail.com
Link: https://lkml.kernel.org/r/20201120231441.29911-10-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f36c2943274199cb8aef32ac96531ffb7c4b43d0 ]
This change renames fcheck_files to files_lookup_fd_rcu. All of the
remaining callers take the rcu_read_lock before calling this function
so the _rcu suffix is appropriate. This change also tightens up the
debug check to verify that all callers hold the rcu_read_lock.
All callers that used to call files_check with the files->file_lock
held have now been changed to call files_lookup_fd_locked.
This change of name has helped remind me of which locks and which
guarantees are in place helping me to catch bugs later in the
patchset.
The need for better names became apparent in the last round of
discussion of this set of changes[1].
[1] https://lkml.kernel.org/r/CAHk-=wj8BQbgJFLa+J0e=iT-1qpmCRTbPAJ8gd6MJQ=kbRPqyQ@mail.gmail.com
Link: https://lkml.kernel.org/r/20201120231441.29911-9-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 120ce2b0cd52abe73e8b16c23461eb14df5a87d8 ]
To make it easy to tell where files->file_lock protection is being
used when looking up a file create files_lookup_fd_locked. Only allow
this function to be called with the file_lock held.
Update the callers of fcheck and fcheck_files that are called with the
files->file_lock held to call files_lookup_fd_locked instead.
Hopefully this makes it easier to quickly understand what is going on.
The need for better names became apparent in the last round of
discussion of this set of changes[1].
[1] https://lkml.kernel.org/r/CAHk-=wj8BQbgJFLa+J0e=iT-1qpmCRTbPAJ8gd6MJQ=kbRPqyQ@mail.gmail.com
Link: https://lkml.kernel.org/r/20201120231441.29911-8-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit bebf684bf330915e6c96313ad7db89a5480fc9c2 ]
The function fcheck despite it's comment is poorly named
as it has no callers that only check it's return value.
All of fcheck's callers use the returned file descriptor.
The same is true for fcheck_files and __fcheck_files.
A new less confusing name is needed. In addition the names
of these functions are confusing as they do not report
the kind of locks that are needed to be held when these
functions are called making error prone to use them.
To remedy this I am making the base functio name lookup_fd
and will and prefixes and sufficies to indicate the rest
of the context.
Name the function (previously called __fcheck_files) that proceeds
from a struct files_struct, looks up the struct file of a file
descriptor, and requires it's callers to verify all of the appropriate
locks are held files_lookup_fd_raw.
The need for better names became apparent in the last round of
discussion of this set of changes[1].
[1] https://lkml.kernel.org/r/CAHk-=wj8BQbgJFLa+J0e=iT-1qpmCRTbPAJ8gd6MJQ=kbRPqyQ@mail.gmail.com
Link: https://lkml.kernel.org/r/20201120231441.29911-7-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
[ cel: adjusted to apply to v5.10.y ]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 950db38ff2c01b7aabbd7ab4a50b7992750fa63d ]
Now that exec no longer needs to restore the previous value of current->files
on error there are no more callers of reset_files_struct so remove it.
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
v1: https://lkml.kernel.org/r/20200817220425.9389-3-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20201120231441.29911-3-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1f702603e7125a390b5cdf5ce00539781cfcc86a ]
Now that exec no longer needs to return the unshared files to their
previous value there is no reason to return displaced.
Instead when unshare_fd creates a copy of the file table, call
put_files_struct before returning from unshare_files.
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
v1: https://lkml.kernel.org/r/20200817220425.9389-2-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20201120231441.29911-2-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 716a8bc7f706eeef80ab42c99d9f210eda845c81 ]
For the case of NFSv4, specify to the client that the pre/post-op
attributes were not recorded atomically with the main operation.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 01cbf3853959feec40ec9b9a399e12a021cd4d81 ]
Don't set PF_LOCAL_THROTTLE on remote filesystems like NFS, since they
aren't expected to ever be subject to double buffering.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d045465fc6cbfa4acfb5a7d817a7c1a57a078109 ]
In order to allow nfsd to accept return values that are not
acceptable to overlayfs and others, add a new function.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7f84b488f9add1d5cca3e6197c95914c7bd3c1cf ]
It's not uncommon for some workloads to do a bunch of I/O to a file and
delete it just afterward. If knfsd has a cached open file however, then
the file may still be open when the dentry is unlinked. If the
underlying filesystem is nfs, then that could trigger it to do a
sillyrename.
On a REMOVE or RENAME scan the nfsd_file cache for open files that
correspond to the inode, and proactively unhash and put their
references. This should prevent any delete-on-last-close activity from
occurring, solely due to knfsd's open file cache.
This must be done synchronously though so we use the variants that call
flush_delayed_fput. There are deadlock possibilities if you call
flush_delayed_fput while holding locks, however. In the case of
nfsd_rename, we don't even do the lookups of the dentries to be renamed
until we've locked for rename.
Once we've figured out what the target dentry is for a rename, check to
see whether there are cached open files associated with it. If there
are, then unwind all of the locking, close them all, and then reattempt
the rename.
None of this is really necessary for "typical" filesystems though. It's
mostly of use for NFS, so declare a new export op flag and use that to
determine whether to close the files beforehand.
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Lance Shelton <lance.shelton@hammerspace.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
[ cel: adjusted to apply to 5.10.y ]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ba5e8187c55555519ae0b63c0fb681391bc42af9 ]
When we start allowing NFS to be reexported, then we have some problems
when it comes to subtree checking. In principle, we could allow it, but
it would mean encoding parent info in the filehandles and there may not
be enough space for that in a NFSv3 filehandle.
To enforce this at export upcall time, we add a new export_ops flag
that declares the filesystem ineligible for subtree checking.
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Lance Shelton <lance.shelton@hammerspace.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit daab110e47f8d7aa6da66923e3ac1a8dbd2b2a72 ]
With NFSv3 nfsd will always attempt to send along WCC data to the
client. This generally involves saving off the in-core inode information
prior to doing the operation on the given filehandle, and then issuing a
vfs_getattr to it after the op.
Some filesystems (particularly clustered or networked ones) have an
expensive ->getattr inode operation. Atomicity is also often difficult
or impossible to guarantee on such filesystems. For those, we're best
off not trying to provide WCC information to the client at all, and to
simply allow it to poll for that information as needed with a GETATTR
RPC.
This patch adds a new flags field to struct export_operations, and
defines a new EXPORT_OP_NOWCC flag that filesystems can use to indicate
that nfsd should not attempt to provide WCC info in NFSv3 replies. It
also adds a blurb about the new flags field and flag to the exporting
documentation.
The server will also now skip collecting this information for NFSv2 as
well, since that info is never used there anyway.
Note that this patch does not add this flag to any filesystem
export_operations structures. This was originally developed to allow
reexporting nfs via nfsd.
Other filesystems may want to consider enabling this flag too. It's hard
to tell however which ones have export operations to enable export via
knfsd and which ones mostly rely on them for open-by-filehandle support,
so I'm leaving that up to the individual maintainers to decide. I am
cc'ing the relevant lists for those filesystems that I think may want to
consider adding this though.
Cc: HPDD-discuss@lists.01.org
Cc: ceph-devel@vger.kernel.org
Cc: cluster-devel@redhat.com
Cc: fuse-devel@lists.sourceforge.net
Cc: ocfs2-devel@oss.oracle.com
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Lance Shelton <lance.shelton@hammerspace.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This reverts commit a85857633b04d57f4524cca0a2bfaf87b2543f9f.
We're still factoring ctime into our change attribute even in the
IS_I_VERSION case. If someone sets the system time backwards, a client
could see the change attribute go backwards. Maybe we can just say
"well, don't do that", but there's some question whether that's good
enough, or whether we need a better guarantee.
Also, the client still isn't actually using the attribute.
While we're still figuring this out, let's just stop returning this
attribute.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 4b03d99794eeed27650597a886247c6427ce1055 ]
Minor cleanup, no change in behavior.
Also pull out a common helper that'll be useful elsewhere.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c1346a1216ab5cb04a265380ac9035d91b16b6d5 ]
Convert the READ_BUF macro in nfs4xdr.c from open code to instead
use the new xdr_stream-style decoders already in use by the encode
side (and by the in-kernel NFS client implementation). Once this
conversion is done, each individual NFSv4 argument decoder can be
independently cleaned up to replace these macros with C code.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5191955d6fc65e6d4efe8f4f10a6028298f57281 ]
A "permanent" struct xdr_stream is allocated in struct svc_rqst so
that it is usable by all server-side decoders. A per-rqst scratch
buffer is also allocated to handle decoding XDR data items that
cross page boundaries.
To demonstrate how it will be used, add the first call site for the
new svcxdr_init_decode() API.
As an additional part of the overall conversion, add symbolic
constants for successful and failed XDR operations. Returning "0" is
overloaded. Sometimes it means something failed, but sometimes it
means success. To make it more clear when XDR decoding functions
succeed or fail, introduce symbolic constants.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
