It's been reported that doing stress test for module insertion and
removal can result in an ENOENT from libkmod for a valid module.
In kernfs_iop_lookup() a negative dentry is created if there's no kernfs
node associated with the dentry or the node is inactive.
But inactive kernfs nodes are meant to be invisible to the VFS and
creating a negative dentry for these can have unexpected side effects
when the node transitions to an active state.
The point of creating negative dentries is to avoid the expensive
alloc/free cycle that occurs if there are frequent lookups for kernfs
attributes that don't exist. So kernfs nodes that are not yet active
should not result in a negative dentry being created so when they
transition to an active state VFS lookups can create an associated
dentry is a natural way.
It's also been reported that https://github.com/osandov/blktests.git
test block/001 hangs during the test. It was suggested that recent
changes to blktests might have caused it but applying this patch
resolved the problem without change to blktests.
Fixes: c7e7c04274 ("kernfs: use VFS negative dentry caching")
Tested-by: Yi Zhang <yi.zhang@redhat.com>
ACKed-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Ian Kent <raven@themaw.net>
Link: https://lore.kernel.org/r/163330943316.19450.15056895533949392922.stgit@mickey.themaw.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A KMSAN warning is reported by Alexander Potapenko:
BUG: KMSAN: uninit-value in kernfs_dop_revalidate+0x61f/0x840
fs/kernfs/dir.c:1053
kernfs_dop_revalidate+0x61f/0x840 fs/kernfs/dir.c:1053
d_revalidate fs/namei.c:854
lookup_dcache fs/namei.c:1522
__lookup_hash+0x3a6/0x590 fs/namei.c:1543
filename_create+0x312/0x7c0 fs/namei.c:3657
do_mkdirat+0x103/0x930 fs/namei.c:3900
__do_sys_mkdir fs/namei.c:3931
__se_sys_mkdir fs/namei.c:3929
__x64_sys_mkdir+0xda/0x120 fs/namei.c:3929
do_syscall_x64 arch/x86/entry/common.c:51
It seems a positive dentry in kernfs becomes a negative dentry directly
through d_delete() in vfs_rmdir(). dentry->d_time is uninitialized
when accessing it in kernfs_dop_revalidate(), because it is only
initialized when created as negative dentry in kernfs_iop_lookup().
The problem can be reproduced by the following command:
cd /sys/fs/cgroup/pids && mkdir hi && stat hi && rmdir hi && stat hi
A simple fixes seems to be initializing d->d_time for positive dentry
in kernfs_iop_lookup() as well. The downside is the negative dentry
will be revalidated again after it becomes negative in d_delete(),
because the revison of its parent must have been increased due to
its removal.
Alternative solution is implement .d_iput for kernfs, and assign d_time
for the newly-generated negative dentry in it. But we may need to
take kernfs_rwsem to protect again the concurrent kernfs_link_sibling()
on the parent directory, it is a little over-killing. Now the simple
fix is chosen.
Link: https://marc.info/?l=linux-fsdevel&m=163249838610499
Fixes: c7e7c04274 ("kernfs: use VFS negative dentry caching")
Reported-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20210928140750.1274441-1-houtao1@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The call to d_splice_alias() in kernfs_iop_lookup() doesn't depend on
any kernfs node so there's no reason to hold the kernfs node lock when
calling it.
Reviewed-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Link: https://lore.kernel.org/r/162642772000.63632.10672683419693513226.stgit@web.messagingengine.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The inode operations .permission() and .getattr() use the kernfs node
write lock but all that's needed is the read lock to protect against
partial updates of these kernfs node fields which are all done under
the write lock.
And .permission() is called frequently during path walks and can cause
quite a bit of contention between kernfs node operations and path
walks when the number of concurrent walks is high.
To change kernfs_iop_getattr() and kernfs_iop_permission() to take
the rw sem read lock instead of the write lock an additional lock is
needed to protect against multiple processes concurrently updating
the inode attributes and link count in kernfs_refresh_inode().
The inode i_lock seems like the sensible thing to use to protect these
inode attribute updates so use it in kernfs_refresh_inode().
The last hunk in the patch, applied to kernfs_fill_super(), is possibly
not needed but taking the lock was present originally. I prefer to
continue to take it to protect against a partial update of the source
kernfs fields during the call to kernfs_refresh_inode() made by
kernfs_get_inode().
Reviewed-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Link: https://lore.kernel.org/r/162642771474.63632.16295959115893904470.stgit@web.messagingengine.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The kernfs global lock restricts the ability to perform kernfs node
lookup operations in parallel during path walks.
Change the kernfs mutex to an rwsem so that, when opportunity arises,
node searches can be done in parallel with path walk lookups.
Reviewed-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Link: https://lore.kernel.org/r/162642770946.63632.2218304587223241374.stgit@web.messagingengine.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If there are many lookups for non-existent paths these negative lookups
can lead to a lot of overhead during path walks.
The VFS allows dentries to be created as negative and hashed, and caches
them so they can be used to reduce the fairly high overhead alloc/free
cycle that occurs during these lookups.
Use the kernfs node parent revision to identify if a change has been
made to the containing directory so that the negative dentry can be
discarded and the lookup redone.
Reviewed-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Link: https://lore.kernel.org/r/162642770420.63632.15791924970508867106.stgit@web.messagingengine.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add a revision counter to kernfs directory nodes so it can be used
to detect if a directory node has changed during negative dentry
revalidation.
There's an assumption that sizeof(unsigned long) <= sizeof(pointer)
on all architectures and as far as I know that assumption holds.
So adding a revision counter to the struct kernfs_elem_dir variant of
the kernfs_node type union won't increase the size of the kernfs_node
struct. This is because struct kernfs_elem_dir is at least
sizeof(pointer) smaller than the largest union variant. It's tempting
to make the revision counter a u64 but that would increase the size of
kernfs_node on archs where sizeof(pointer) is smaller than the revision
counter.
Reviewed-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Link: https://lore.kernel.org/r/162642769895.63632.8356662784964509867.stgit@web.messagingengine.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here is the small set of driver core and debugfs updates for 5.14-rc1.
Included in here are:
- debugfs api cleanups (touched some drivers)
- devres updates
- tiny driver core updates and tweaks
Nothing major in here at all, and all have been in linux-next for a
while with no reported issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core changes from Greg KH:
"Here is the small set of driver core and debugfs updates for 5.14-rc1.
Included in here are:
- debugfs api cleanups (touched some drivers)
- devres updates
- tiny driver core updates and tweaks
Nothing major in here at all, and all have been in linux-next for a
while with no reported issues"
* tag 'driver-core-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (27 commits)
docs: ABI: testing: sysfs-firmware-memmap: add some memmap types.
devres: Enable trace events
devres: No need to call remove_nodes() when there none present
devres: Use list_for_each_safe_from() in remove_nodes()
devres: Make locking straight forward in release_nodes()
kernfs: move revalidate to be near lookup
drivers/base: Constify static attribute_group structs
firmware_loader: remove unneeded 'comma' macro
devcoredump: remove contact information
driver core: Drop helper devm_platform_ioremap_resource_wc()
component: Rename 'dev' to 'parent'
component: Drop 'dev' argument to component_match_realloc()
device property: Don't check for NULL twice in the loops
driver core: auxiliary bus: Fix typo in the docs
drivers/base/node.c: make CACHE_ATTR define static DEVICE_ATTR_RO
debugfs: remove return value of debugfs_create_ulong()
debugfs: remove return value of debugfs_create_bool()
scsi: snic: debugfs: remove local storage of debugfs files
b43: don't save dentries for debugfs
b43legacy: don't save dentries for debugfs
...
Move the ramfs aops to libfs and reuse them for kernfs and configfs.
Thosw two did not wire up ->set_page_dirty before and now get
__set_page_dirty_no_writeback, which is the right one for no-writeback
address_space usage.
Drop the now unused exports of the libfs helpers only used for ramfs-style
pagecache usage.
Link: https://lkml.kernel.org/r/20210614061512.3966143-3-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
While the dentry operation kernfs_dop_revalidate() is grouped with
dentry type functions it also has a strong affinity to the inode
operation ->lookup().
It makes sense to locate this function near to kernfs_iop_lookup()
because we will be adding VFS negative dentry caching to reduce path
lookup overhead for non-existent paths.
There's no functional change from this patch.
Signed-off-by: Ian Kent <raven@themaw.net>
Reviewed-by: Miklos Szeredi <mszeredi@redhat.com>
Link: https://lore.kernel.org/r/162375275365.232295.8995526416263659926.stgit@web.messagingengine.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'idmapped-mounts-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux
Pull idmapped mounts from Christian Brauner:
"This introduces idmapped mounts which has been in the making for some
time. Simply put, different mounts can expose the same file or
directory with different ownership. This initial implementation comes
with ports for fat, ext4 and with Christoph's port for xfs with more
filesystems being actively worked on by independent people and
maintainers.
Idmapping mounts handle a wide range of long standing use-cases. Here
are just a few:
- Idmapped mounts make it possible to easily share files between
multiple users or multiple machines especially in complex
scenarios. For example, idmapped mounts will be used in the
implementation of portable home directories in
systemd-homed.service(8) where they allow users to move their home
directory to an external storage device and use it on multiple
computers where they are assigned different uids and gids. This
effectively makes it possible to assign random uids and gids at
login time.
- It is possible to share files from the host with unprivileged
containers without having to change ownership permanently through
chown(2).
- It is possible to idmap a container's rootfs and without having to
mangle every file. For example, Chromebooks use it to share the
user's Download folder with their unprivileged containers in their
Linux subsystem.
- It is possible to share files between containers with
non-overlapping idmappings.
- Filesystem that lack a proper concept of ownership such as fat can
use idmapped mounts to implement discretionary access (DAC)
permission checking.
- They allow users to efficiently changing ownership on a per-mount
basis without having to (recursively) chown(2) all files. In
contrast to chown (2) changing ownership of large sets of files is
instantenous with idmapped mounts. This is especially useful when
ownership of a whole root filesystem of a virtual machine or
container is changed. With idmapped mounts a single syscall
mount_setattr syscall will be sufficient to change the ownership of
all files.
- Idmapped mounts always take the current ownership into account as
idmappings specify what a given uid or gid is supposed to be mapped
to. This contrasts with the chown(2) syscall which cannot by itself
take the current ownership of the files it changes into account. It
simply changes the ownership to the specified uid and gid. This is
especially problematic when recursively chown(2)ing a large set of
files which is commong with the aforementioned portable home
directory and container and vm scenario.
- Idmapped mounts allow to change ownership locally, restricting it
to specific mounts, and temporarily as the ownership changes only
apply as long as the mount exists.
Several userspace projects have either already put up patches and
pull-requests for this feature or will do so should you decide to pull
this:
- systemd: In a wide variety of scenarios but especially right away
in their implementation of portable home directories.
https://systemd.io/HOME_DIRECTORY/
- container runtimes: containerd, runC, LXD:To share data between
host and unprivileged containers, unprivileged and privileged
containers, etc. The pull request for idmapped mounts support in
containerd, the default Kubernetes runtime is already up for quite
a while now: https://github.com/containerd/containerd/pull/4734
- The virtio-fs developers and several users have expressed interest
in using this feature with virtual machines once virtio-fs is
ported.
- ChromeOS: Sharing host-directories with unprivileged containers.
I've tightly synced with all those projects and all of those listed
here have also expressed their need/desire for this feature on the
mailing list. For more info on how people use this there's a bunch of
talks about this too. Here's just two recent ones:
https://www.cncf.io/wp-content/uploads/2020/12/Rootless-Containers-in-Gitpod.pdfhttps://fosdem.org/2021/schedule/event/containers_idmap/
This comes with an extensive xfstests suite covering both ext4 and
xfs:
https://git.kernel.org/brauner/xfstests-dev/h/idmapped_mounts
It covers truncation, creation, opening, xattrs, vfscaps, setid
execution, setgid inheritance and more both with idmapped and
non-idmapped mounts. It already helped to discover an unrelated xfs
setgid inheritance bug which has since been fixed in mainline. It will
be sent for inclusion with the xfstests project should you decide to
merge this.
In order to support per-mount idmappings vfsmounts are marked with
user namespaces. The idmapping of the user namespace will be used to
map the ids of vfs objects when they are accessed through that mount.
By default all vfsmounts are marked with the initial user namespace.
The initial user namespace is used to indicate that a mount is not
idmapped. All operations behave as before and this is verified in the
testsuite.
Based on prior discussions we want to attach the whole user namespace
and not just a dedicated idmapping struct. This allows us to reuse all
the helpers that already exist for dealing with idmappings instead of
introducing a whole new range of helpers. In addition, if we decide in
the future that we are confident enough to enable unprivileged users
to setup idmapped mounts the permission checking can take into account
whether the caller is privileged in the user namespace the mount is
currently marked with.
The user namespace the mount will be marked with can be specified by
passing a file descriptor refering to the user namespace as an
argument to the new mount_setattr() syscall together with the new
MOUNT_ATTR_IDMAP flag. The system call follows the openat2() pattern
of extensibility.
The following conditions must be met in order to create an idmapped
mount:
- The caller must currently have the CAP_SYS_ADMIN capability in the
user namespace the underlying filesystem has been mounted in.
- The underlying filesystem must support idmapped mounts.
- The mount must not already be idmapped. This also implies that the
idmapping of a mount cannot be altered once it has been idmapped.
- The mount must be a detached/anonymous mount, i.e. it must have
been created by calling open_tree() with the OPEN_TREE_CLONE flag
and it must not already have been visible in the filesystem.
The last two points guarantee easier semantics for userspace and the
kernel and make the implementation significantly simpler.
By default vfsmounts are marked with the initial user namespace and no
behavioral or performance changes are observed.
The manpage with a detailed description can be found here:
1d7b902e28
In order to support idmapped mounts, filesystems need to be changed
and mark themselves with the FS_ALLOW_IDMAP flag in fs_flags. The
patches to convert individual filesystem are not very large or
complicated overall as can be seen from the included fat, ext4, and
xfs ports. Patches for other filesystems are actively worked on and
will be sent out separately. The xfstestsuite can be used to verify
that port has been done correctly.
The mount_setattr() syscall is motivated independent of the idmapped
mounts patches and it's been around since July 2019. One of the most
valuable features of the new mount api is the ability to perform
mounts based on file descriptors only.
Together with the lookup restrictions available in the openat2()
RESOLVE_* flag namespace which we added in v5.6 this is the first time
we are close to hardened and race-free (e.g. symlinks) mounting and
path resolution.
While userspace has started porting to the new mount api to mount
proper filesystems and create new bind-mounts it is currently not
possible to change mount options of an already existing bind mount in
the new mount api since the mount_setattr() syscall is missing.
With the addition of the mount_setattr() syscall we remove this last
restriction and userspace can now fully port to the new mount api,
covering every use-case the old mount api could. We also add the
crucial ability to recursively change mount options for a whole mount
tree, both removing and adding mount options at the same time. This
syscall has been requested multiple times by various people and
projects.
There is a simple tool available at
https://github.com/brauner/mount-idmapped
that allows to create idmapped mounts so people can play with this
patch series. I'll add support for the regular mount binary should you
decide to pull this in the following weeks:
Here's an example to a simple idmapped mount of another user's home
directory:
u1001@f2-vm:/$ sudo ./mount --idmap both:1000:1001:1 /home/ubuntu/ /mnt
u1001@f2-vm:/$ ls -al /home/ubuntu/
total 28
drwxr-xr-x 2 ubuntu ubuntu 4096 Oct 28 22:07 .
drwxr-xr-x 4 root root 4096 Oct 28 04:00 ..
-rw------- 1 ubuntu ubuntu 3154 Oct 28 22:12 .bash_history
-rw-r--r-- 1 ubuntu ubuntu 220 Feb 25 2020 .bash_logout
-rw-r--r-- 1 ubuntu ubuntu 3771 Feb 25 2020 .bashrc
-rw-r--r-- 1 ubuntu ubuntu 807 Feb 25 2020 .profile
-rw-r--r-- 1 ubuntu ubuntu 0 Oct 16 16:11 .sudo_as_admin_successful
-rw------- 1 ubuntu ubuntu 1144 Oct 28 00:43 .viminfo
u1001@f2-vm:/$ ls -al /mnt/
total 28
drwxr-xr-x 2 u1001 u1001 4096 Oct 28 22:07 .
drwxr-xr-x 29 root root 4096 Oct 28 22:01 ..
-rw------- 1 u1001 u1001 3154 Oct 28 22:12 .bash_history
-rw-r--r-- 1 u1001 u1001 220 Feb 25 2020 .bash_logout
-rw-r--r-- 1 u1001 u1001 3771 Feb 25 2020 .bashrc
-rw-r--r-- 1 u1001 u1001 807 Feb 25 2020 .profile
-rw-r--r-- 1 u1001 u1001 0 Oct 16 16:11 .sudo_as_admin_successful
-rw------- 1 u1001 u1001 1144 Oct 28 00:43 .viminfo
u1001@f2-vm:/$ touch /mnt/my-file
u1001@f2-vm:/$ setfacl -m u:1001:rwx /mnt/my-file
u1001@f2-vm:/$ sudo setcap -n 1001 cap_net_raw+ep /mnt/my-file
u1001@f2-vm:/$ ls -al /mnt/my-file
-rw-rwxr--+ 1 u1001 u1001 0 Oct 28 22:14 /mnt/my-file
u1001@f2-vm:/$ ls -al /home/ubuntu/my-file
-rw-rwxr--+ 1 ubuntu ubuntu 0 Oct 28 22:14 /home/ubuntu/my-file
u1001@f2-vm:/$ getfacl /mnt/my-file
getfacl: Removing leading '/' from absolute path names
# file: mnt/my-file
# owner: u1001
# group: u1001
user::rw-
user:u1001:rwx
group::rw-
mask::rwx
other::r--
u1001@f2-vm:/$ getfacl /home/ubuntu/my-file
getfacl: Removing leading '/' from absolute path names
# file: home/ubuntu/my-file
# owner: ubuntu
# group: ubuntu
user::rw-
user:ubuntu:rwx
group::rw-
mask::rwx
other::r--"
* tag 'idmapped-mounts-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: (41 commits)
xfs: remove the possibly unused mp variable in xfs_file_compat_ioctl
xfs: support idmapped mounts
ext4: support idmapped mounts
fat: handle idmapped mounts
tests: add mount_setattr() selftests
fs: introduce MOUNT_ATTR_IDMAP
fs: add mount_setattr()
fs: add attr_flags_to_mnt_flags helper
fs: split out functions to hold writers
namespace: only take read lock in do_reconfigure_mnt()
mount: make {lock,unlock}_mount_hash() static
namespace: take lock_mount_hash() directly when changing flags
nfs: do not export idmapped mounts
overlayfs: do not mount on top of idmapped mounts
ecryptfs: do not mount on top of idmapped mounts
ima: handle idmapped mounts
apparmor: handle idmapped mounts
fs: make helpers idmap mount aware
exec: handle idmapped mounts
would_dump: handle idmapped mounts
...
Extend some inode methods with an additional user namespace argument. A
filesystem that is aware of idmapped mounts will receive the user
namespace the mount has been marked with. This can be used for
additional permission checking and also to enable filesystems to
translate between uids and gids if they need to. We have implemented all
relevant helpers in earlier patches.
As requested we simply extend the exisiting inode method instead of
introducing new ones. This is a little more code churn but it's mostly
mechanical and doesnt't leave us with additional inode methods.
Link: https://lore.kernel.org/r/20210121131959.646623-25-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
The generic_fillattr() helper fills in the basic attributes associated
with an inode. Enable it to handle idmapped mounts. If the inode is
accessed through an idmapped mount map it into the mount's user
namespace before we store the uid and gid. If the initial user namespace
is passed nothing changes so non-idmapped mounts will see identical
behavior as before.
Link: https://lore.kernel.org/r/20210121131959.646623-12-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
The posix acl permission checking helpers determine whether a caller is
privileged over an inode according to the acls associated with the
inode. Add helpers that make it possible to handle acls on idmapped
mounts.
The vfs and the filesystems targeted by this first iteration make use of
posix_acl_fix_xattr_from_user() and posix_acl_fix_xattr_to_user() to
translate basic posix access and default permissions such as the
ACL_USER and ACL_GROUP type according to the initial user namespace (or
the superblock's user namespace) to and from the caller's current user
namespace. Adapt these two helpers to handle idmapped mounts whereby we
either map from or into the mount's user namespace depending on in which
direction we're translating.
Similarly, cap_convert_nscap() is used by the vfs to translate user
namespace and non-user namespace aware filesystem capabilities from the
superblock's user namespace to the caller's user namespace. Enable it to
handle idmapped mounts by accounting for the mount's user namespace.
In addition the fileystems targeted in the first iteration of this patch
series make use of the posix_acl_chmod() and, posix_acl_update_mode()
helpers. Both helpers perform permission checks on the target inode. Let
them handle idmapped mounts. These two helpers are called when posix
acls are set by the respective filesystems to handle this case we extend
the ->set() method to take an additional user namespace argument to pass
the mount's user namespace down.
Link: https://lore.kernel.org/r/20210121131959.646623-9-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
When file attributes are changed most filesystems rely on the
setattr_prepare(), setattr_copy(), and notify_change() helpers for
initialization and permission checking. Let them handle idmapped mounts.
If the inode is accessed through an idmapped mount map it into the
mount's user namespace. Afterwards the checks are identical to
non-idmapped mounts. If the initial user namespace is passed nothing
changes so non-idmapped mounts will see identical behavior as before.
Helpers that perform checks on the ia_uid and ia_gid fields in struct
iattr assume that ia_uid and ia_gid are intended values and have already
been mapped correctly at the userspace-kernelspace boundary as we
already do today. If the initial user namespace is passed nothing
changes so non-idmapped mounts will see identical behavior as before.
Link: https://lore.kernel.org/r/20210121131959.646623-8-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
The two helpers inode_permission() and generic_permission() are used by
the vfs to perform basic permission checking by verifying that the
caller is privileged over an inode. In order to handle idmapped mounts
we extend the two helpers with an additional user namespace argument.
On idmapped mounts the two helpers will make sure to map the inode
according to the mount's user namespace and then peform identical
permission checks to inode_permission() and generic_permission(). If the
initial user namespace is passed nothing changes so non-idmapped mounts
will see identical behavior as before.
Link: https://lore.kernel.org/r/20210121131959.646623-6-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Wire up the splice_read and splice_write methods to the default
helpers using ->read_iter and ->write_iter now that those are
implemented for kernfs. This restores support to use splice and
sendfile on kernfs files.
Fixes: 36e2c7421f ("fs: don't allow splice read/write without explicit ops")
Reported-by: Siddharth Gupta <sidgup@codeaurora.org>
Tested-by: Siddharth Gupta <sidgup@codeaurora.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210120204631.274206-4-hch@lst.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Switch kernfs to implement the write_iter method instead of plain old
write to prepare to supporting splice and sendfile again.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210120204631.274206-3-hch@lst.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Switch kernfs to implement the read_iter method instead of plain old
read to prepare to supporting splice and sendfile again.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210120204631.274206-2-hch@lst.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In both kernfs_node_from_dentry() and in
kernfs_dentry_node(), we will check the dentry->inode
is NULL or not, which is superfluous.
So remove the check in kernfs_node_from_dentry().
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Hui Su <sh_def@163.com>
Link: https://lore.kernel.org/r/20201113132143.GA119541@rlk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix two stragglers in the comments of the below rename operation.
Fixes: adc5e8b58f ("kernfs: drop s_ prefix from kernfs_node members")
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/20201015185726.1386868-1-willemdebruijn.kernel@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The arguments of fsnotify() are overloaded and mean different things
for different event types.
Replace the to_tell argument with separate arguments @dir and @inode,
because we may be sending to both dir and child. Using the @data
argument to pass the child is not enough, because dirent events pass
this argument (for audit), but we do not report to child.
Document the new fsnotify() function argumenets.
Link: https://lore.kernel.org/r/20200722125849.17418-7-amir73il@gmail.com
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Instead of calling fsnotify() twice, once with parent inode and once
with child inode, if event should be sent to parent inode, send it
with both parent and child inodes marks in object type iterator and call
the backend handle_event() callback only once.
The parent inode is assigned to the standard "inode" iterator type and
the child inode is assigned to the special "child" iterator type.
In that case, the bit FS_EVENT_ON_CHILD will be set in the event mask,
the dir argument to handle_event will be the parent inode, the file_name
argument to handle_event is non NULL and refers to the name of the child
and the child inode can be accessed with fsnotify_data_inode().
This will allow fanotify to make decisions based on child or parent's
ignored mask. For example, when a parent is interested in a specific
event on its children, but a specific child wishes to ignore this event,
the event will not be reported. This is not what happens with current
code, but according to man page, it is the expected behavior.
Link: https://lore.kernel.org/r/20200716084230.30611-15-amir73il@gmail.com
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
When creating an FS_MODIFY event on inode itself (not on parent)
the file_name argument should be NULL.
The change to send a non NULL name to inode itself was done on purpuse
as part of another commit, as Tejun writes: "...While at it, supply the
target file name to fsnotify() from kernfs_node->name.".
But this is wrong practice and inconsistent with inotify behavior when
watching a single file. When a child is being watched (as opposed to the
parent directory) the inotify event should contain the watch descriptor,
but not the file name.
Fixes: df6a58c5c5 ("kernfs: don't depend on d_find_any_alias()...")
Link: https://lore.kernel.org/r/20200708111156.24659-5-amir73il@gmail.com
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
The kernfs_node lockdep tracking is being done on kn->active, the
active reference count. The other reference count (kn->count) is not
tracked by lockdep. So change the lockdep name to reflect what it is
tracking.
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20200402171056.27871-1-longman@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
User extended attributes are useful as metadata storage for kernfs
consumers like cgroups. Especially in the case of cgroups, it is useful
to have a central metadata store that multiple processes/services can
use to coordinate actions.
A concrete example is for userspace out of memory killers. We want to
let delegated cgroup subtree owners (running as non-root) to be able to
say "please avoid killing this cgroup". This is especially important for
desktop linux as delegated subtrees owners are less likely to run as
root.
This patch introduces a new flag, KERNFS_ROOT_SUPPORT_USER_XATTR, that
lets kernfs consumers enable user xattr support. An initial limit of 128
entries or 128KB -- whichever is hit first -- is placed per cgroup
because xattrs come from kernel memory and we don't want to let
unprivileged users accidentally eat up too much kernel memory.
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Acked-by: Chris Down <chris@chrisdown.name>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
This helps set up size accounting in the next commit. Without this out
param, it's difficult to find out the removed xattr size without taking
a lock for longer and walking the xattr linked list twice.
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Acked-by: Chris Down <chris@chrisdown.name>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Previously there was an additional check if variable pos is not null.
However, this check happens after entering while loop and only then,
which can happen only if pos is not null.
Therefore the additional check is redundant and can be removed.
Signed-off-by: Mateusz Nosek <mateusznosek0@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20191230191628.21099-1-mateusznosek0@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull vfs d_inode/d_flags memory ordering fixes from Al Viro:
"Fallout from tree-wide audit for ->d_inode/->d_flags barriers use.
Basically, the problem is that negative pinned dentries require
careful treatment - unless ->d_lock is locked or parent is held at
least shared, another thread can make them positive right under us.
Most of the uses turned out to be safe - the main surprises as far as
filesystems are concerned were
- race in dget_parent() fastpath, that might end up with the caller
observing the returned dentry _negative_, due to insufficient
barriers. It is positive in memory, but we could end up seeing the
wrong value of ->d_inode in CPU cache. Fixed.
- manual checks that result of lookup_one_len_unlocked() is positive
(and rejection of negatives). Again, insufficient barriers (we
might end up with inconsistent observed values of ->d_inode and
->d_flags). Fixed by switching to a new primitive that does the
checks itself and returns ERR_PTR(-ENOENT) instead of a negative
dentry. That way we get rid of boilerplate converting negatives
into ERR_PTR(-ENOENT) in the callers and have a single place to
deal with the barrier-related mess - inside fs/namei.c rather than
in every caller out there.
The guts of pathname resolution *do* need to be careful - the race
found by Ritesh is real, as well as several similar races.
Fortunately, it turns out that we can take care of that with fairly
local changes in there.
The tree-wide audit had not been fun, and I hate the idea of repeating
it. I think the right approach would be to annotate the places where
we are _not_ guaranteed ->d_inode/->d_flags stability and have sparse
catch regressions. But I'm still not sure what would be the least
invasive way of doing that and it's clearly the next cycle fodder"
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fs/namei.c: fix missing barriers when checking positivity
fix dget_parent() fastpath race
new helper: lookup_positive_unlocked()
fs/namei.c: pull positivity check into follow_managed()
Pull locking updates from Ingo Molnar:
"The main changes in this cycle were:
- A comprehensive rewrite of the robust/PI futex code's exit handling
to fix various exit races. (Thomas Gleixner et al)
- Rework the generic REFCOUNT_FULL implementation using
atomic_fetch_* operations so that the performance impact of the
cmpxchg() loops is mitigated for common refcount operations.
With these performance improvements the generic implementation of
refcount_t should be good enough for everybody - and this got
confirmed by performance testing, so remove ARCH_HAS_REFCOUNT and
REFCOUNT_FULL entirely, leaving the generic implementation enabled
unconditionally. (Will Deacon)
- Other misc changes, fixes, cleanups"
* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits)
lkdtm: Remove references to CONFIG_REFCOUNT_FULL
locking/refcount: Remove unused 'refcount_error_report()' function
locking/refcount: Consolidate implementations of refcount_t
locking/refcount: Consolidate REFCOUNT_{MAX,SATURATED} definitions
locking/refcount: Move saturation warnings out of line
locking/refcount: Improve performance of generic REFCOUNT_FULL code
locking/refcount: Move the bulk of the REFCOUNT_FULL implementation into the <linux/refcount.h> header
locking/refcount: Remove unused refcount_*_checked() variants
locking/refcount: Ensure integer operands are treated as signed
locking/refcount: Define constants for saturation and max refcount values
futex: Prevent exit livelock
futex: Provide distinct return value when owner is exiting
futex: Add mutex around futex exit
futex: Provide state handling for exec() as well
futex: Sanitize exit state handling
futex: Mark the begin of futex exit explicitly
futex: Set task::futex_state to DEAD right after handling futex exit
futex: Split futex_mm_release() for exit/exec
exit/exec: Seperate mm_release()
futex: Replace PF_EXITPIDONE with a state
...
Most of the callers of lookup_one_len_unlocked() treat negatives are
ERR_PTR(-ENOENT). Provide a helper that would do just that. Note
that a pinned positive dentry remains positive - it's ->d_inode is
stable, etc.; a pinned _negative_ dentry can become positive at any
point as long as you are not holding its parent at least shared.
So using lookup_one_len_unlocked() needs to be careful;
lookup_positive_unlocked() is safer and that's what the callers
end up open-coding anyway.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Each kernfs_node is identified with a 64bit ID. The low 32bit is
exposed as ino and the high gen. While this already allows using inos
as keys by looking up with wildcard generation number of 0, it's
adding unnecessary complications for 64bit ino archs which can
directly use kernfs_node IDs as inos to uniquely identify each cgroup
instance.
This patch exposes IDs directly as inos on 64bit ino archs. The
conversion is mostly straight-forward.
* 32bit ino archs behave the same as before. 64bit ino archs now use
the whole 64bit ID as ino and the generation number is fixed at 1.
* 64bit inos still use the same idr allocator which gurantees that the
lower 32bits identify the current live instance uniquely and the
high 32bits are incremented whenever the low bits wrap. As the
upper 32bits are no longer used as gen and we don't wanna start ino
allocation with 33rd bit set, the initial value for highbits
allocation is changed to 0 on 64bit ino archs.
* blktrace exposes two 32bit numbers - (INO,GEN) pair - to identify
the issuing cgroup. Userland builds FILEID_INO32_GEN fids from
these numbers to look up the cgroups. To remain compatible with the
behavior, always output (LOW32,HIGH32) which will be constructed
back to the original 64bit ID by __kernfs_fh_to_dentry().
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
The current kernfs exportfs implementation uses the generic_fh_*()
helpers and FILEID_INO32_GEN[_PARENT] which limits ino to 32bits.
Let's implement custom exportfs operations and fid type to remove the
restriction.
* FILEID_KERNFS is a single u64 value whose content is
kernfs_node->id. This is the only native fid type.
* For backward compatibility with blk_log_action() path which exposes
(ino,gen) pairs which userland assembles into FILEID_INO32_GEN keys,
combine the generic keys into 64bit IDs in the same order.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
kernfs_find_and_get_node_by_ino() looks the kernfs_node matching the
specified ino. On top of that, kernfs_get_node_by_id() and
kernfs_fh_get_inode() implement full ID matching by testing the rest
of ID.
On surface, confusingly, the two are slightly different in that the
latter uses 0 gen as wildcard while the former doesn't - does it mean
that the latter can't uniquely identify inodes w/ 0 gen? In practice,
this is a distinction without a difference because generation number
starts at 1. There are no actual IDs with 0 gen, so it can always
safely used as wildcard.
Let's simplify the code by renaming kernfs_find_and_get_node_by_ino()
to kernfs_find_and_get_node_by_id(), moving all lookup logics into it,
and removing now unnecessary kernfs_get_node_by_id().
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
kernfs_node->id is currently a union kernfs_node_id which represents
either a 32bit (ino, gen) pair or u64 value. I can't see much value
in the usage of the union - all that's needed is a 64bit ID which the
current code is already limited to. Using a union makes the code
unnecessarily complicated and prevents using 64bit ino without adding
practical benefits.
This patch drops union kernfs_node_id and makes kernfs_node->id a u64.
ino is stored in the lower 32bits and gen upper. Accessors -
kernfs[_id]_ino() and kernfs[_id]_gen() - are added to retrieve the
ino and gen. This simplifies ID handling less cumbersome and will
allow using 64bit inos on supported archs.
This patch doesn't make any functional changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Alexei Starovoitov <ast@kernel.org>
kernfs node can be created in two separate steps - allocation and
activation. This is used to make kernfs nodes visible only after the
internal states attached to the node are fully initialized.
kernfs_find_and_get_node_by_id() currently allows lookups of nodes
which aren't activated yet and thus can expose nodes are which are
still being prepped by kernfs users.
Fix it by disallowing lookups of nodes which aren't activated yet.
kernfs_find_and_get_node_by_ino()
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
kernfs_find_and_get_node_by_ino() uses RCU protection. It's currently
a bit buggy because it can look up a node which hasn't been activated
yet and thus may end up exposing a node that the kernfs user is still
prepping.
While it can be fixed by pushing it further in the current direction,
it's already complicated and isn't clear whether the complexity is
justified. The main use of kernfs_find_and_get_node_by_ino() is for
exportfs operations. They aren't super hot and all the follow-up
operations (e.g. mapping to path) use normal locking anyway.
Let's switch to a dumber locking scheme and protect the lookup with
kernfs_idr_lock.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
When the 32bit ino wraps around, kernfs increments the generation
number to distinguish reused ino instances. The wrap-around detection
tests whether the allocated ino is lower than what the cursor but the
cursor is pointing to the next ino to allocate so the condition never
triggers.
Fix it by remembering the last ino and comparing against that.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fixes: 4a3ef68aca ("kernfs: implement i_generation")
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: stable@vger.kernel.org # v4.14+
This series from Deepa Dinamani adds a per-superblock minimum/maximum
timestamp limit for a file system, and clamps timestamps as they are
written, to avoid random behavior from integer overflow as well as having
different time stamps on disk vs in memory.
At mount time, a warning is now printed for any file system that can
represent current timestamps but not future timestamps more than 30
years into the future, similar to the arbitrary 30 year limit that was
added to settimeofday().
This was picked as a compromise to warn users to migrate to other file
systems (e.g. ext4 instead of ext3) when they need the file system to
survive beyond 2038 (or similar limits in other file systems), but not
get in the way of normal usage.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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Merge tag 'y2038-vfs' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground
Pull y2038 vfs updates from Arnd Bergmann:
"Add inode timestamp clamping.
This series from Deepa Dinamani adds a per-superblock minimum/maximum
timestamp limit for a file system, and clamps timestamps as they are
written, to avoid random behavior from integer overflow as well as
having different time stamps on disk vs in memory.
At mount time, a warning is now printed for any file system that can
represent current timestamps but not future timestamps more than 30
years into the future, similar to the arbitrary 30 year limit that was
added to settimeofday().
This was picked as a compromise to warn users to migrate to other file
systems (e.g. ext4 instead of ext3) when they need the file system to
survive beyond 2038 (or similar limits in other file systems), but not
get in the way of normal usage"
* tag 'y2038-vfs' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground:
ext4: Reduce ext4 timestamp warnings
isofs: Initialize filesystem timestamp ranges
pstore: fs superblock limits
fs: omfs: Initialize filesystem timestamp ranges
fs: hpfs: Initialize filesystem timestamp ranges
fs: ceph: Initialize filesystem timestamp ranges
fs: sysv: Initialize filesystem timestamp ranges
fs: affs: Initialize filesystem timestamp ranges
fs: fat: Initialize filesystem timestamp ranges
fs: cifs: Initialize filesystem timestamp ranges
fs: nfs: Initialize filesystem timestamp ranges
ext4: Initialize timestamps limits
9p: Fill min and max timestamps in sb
fs: Fill in max and min timestamps in superblock
utimes: Clamp the timestamps before update
mount: Add mount warning for impending timestamp expiry
timestamp_truncate: Replace users of timespec64_trunc
vfs: Add timestamp_truncate() api
vfs: Add file timestamp range support
In kernfs_path_from_node_locked(), there is an if statement on line 147
to check whether buf is NULL:
if (buf)
When buf is NULL, it is used on line 151:
len += strlcpy(buf + len, parent_str, ...)
and line 158:
len += strlcpy(buf + len, "/", ...)
and line 160:
len += strlcpy(buf + len, kn->name, ...)
Thus, possible null-pointer dereferences may occur.
To fix these possible bugs, buf is checked before being used.
If it is NULL, -EINVAL is returned.
These bugs are found by a static analysis tool STCheck written by us.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Link: https://lore.kernel.org/r/20190724022242.27505-1-baijiaju1990@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Get root safely after kn is ensureed to be not null.
Signed-off-by: Peng Wang <rocking@whu.edu.cn>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20190708151611.13242-1-rocking@whu.edu.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Based on 1 normalized pattern(s):
this file is released under the gplv2
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 68 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190114.292346262@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add SPDX license identifiers to all Make/Kconfig files which:
- Have no license information of any form
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:
GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull misc dcache updates from Al Viro:
"Most of this pile is putting name length into struct name_snapshot and
making use of it.
The beginning of this series ("ovl_lookup_real_one(): don't bother
with strlen()") ought to have been split in two (separate switch of
name_snapshot to struct qstr from overlayfs reaping the trivial
benefits of that), but I wanted to avoid a rebase - by the time I'd
spotted that it was (a) in -next and (b) close to 5.1-final ;-/"
* 'work.dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
audit_compare_dname_path(): switch to const struct qstr *
audit_update_watch(): switch to const struct qstr *
inotify_handle_event(): don't bother with strlen()
fsnotify: switch send_to_group() and ->handle_event to const struct qstr *
fsnotify(): switch to passing const struct qstr * for file_name
switch fsnotify_move() to passing const struct qstr * for old_name
ovl_lookup_real_one(): don't bother with strlen()
sysv: bury the broken "quietly truncate the long filenames" logics
nsfs: unobfuscate
unexport d_alloc_pseudo()
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Merge tag 'selinux-pr-20190507' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux
Pull selinux updates from Paul Moore:
"We've got a few SELinux patches for the v5.2 merge window, the
highlights are below:
- Add LSM hooks, and the SELinux implementation, for proper labeling
of kernfs. While we are only including the SELinux implementation
here, the rest of the LSM folks have given the hooks a thumbs-up.
- Update the SELinux mdp (Make Dummy Policy) script to actually work
on a modern system.
- Disallow userspace to change the LSM credentials via
/proc/self/attr when the task's credentials are already overridden.
The change was made in procfs because all the LSM folks agreed this
was the Right Thing To Do and duplicating it across each LSM was
going to be annoying"
* tag 'selinux-pr-20190507' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
proc: prevent changes to overridden credentials
selinux: Check address length before reading address family
kernfs: fix xattr name handling in LSM helpers
MAINTAINERS: update SELinux file patterns
selinux: avoid uninitialized variable warning
selinux: remove useless assignments
LSM: lsm_hooks.h - fix missing colon in docstring
selinux: Make selinux_kernfs_init_security static
kernfs: initialize security of newly created nodes
selinux: implement the kernfs_init_security hook
LSM: add new hook for kernfs node initialization
kernfs: use simple_xattrs for security attributes
selinux: try security xattr after genfs for kernfs filesystems
kernfs: do not alloc iattrs in kernfs_xattr_get
kernfs: clean up struct kernfs_iattrs
scripts/selinux: fix build
selinux: use kernel linux/socket.h for genheaders and mdp
scripts/selinux: modernize mdp
Note that in fnsotify_move() and fsnotify_link() we are guaranteed
that dentry->d_name won't change during the fsnotify() evaluation
(by having the parent directory locked exclusive), so we don't
need to fetch dentry->d_name.name in the callers. In fsnotify_dirent()
the same stability of dentry->d_name is also true, but it's a bit
more convoluted - there is one callchain (devpts_pty_new() ->
fsnotify_create() -> fsnotify_dirent()) where the parent is _not_
locked, but on devpts ->d_name of everything is unchanging; it
has neither explicit nor implicit renames.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
smp_mb__before_atomic() can not be applied to atomic_set(). Remove the
barrier and rely on RELEASE synchronization.
Fixes: ba16b2846a ("kernfs: add an API to get kernfs node from inode number")
Cc: stable@vger.kernel.org
Signed-off-by: Andrea Parri <andrea.parri@amarulasolutions.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The implementation of kernfs_security_xattr_*() helpers reuses the
kernfs_node_xattr_*() functions, which take the suffix of the xattr name
and extract full xattr name from it using xattr_full_name(). However,
this function relies on the fact that the suffix passed to xattr
handlers from VFS is always constructed from the full name by just
incerementing the pointer. This doesn't necessarily hold for the callers
of kernfs_security_xattr_*(), so their usage will easily lead to
out-of-bounds access.
Fix this by moving the xattr name reconstruction to the VFS xattr
handlers and replacing the kernfs_security_xattr_*() helpers with more
general kernfs_xattr_*() helpers that take full xattr name and allow
accessing all kernfs node's xattrs.
Reported-by: kernel test robot <rong.a.chen@intel.com>
Fixes: b230d5aba2 ("LSM: add new hook for kernfs node initialization")
Fixes: ec882da5cd ("selinux: implement the kernfs_init_security hook")
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Use the new security_kernfs_init_security() hook to allow LSMs to
possibly assign a non-default security context to a newly created kernfs
node based on the attributes of the new node and also its parent node.
This fixes an issue with cgroupfs under SELinux, where newly created
cgroup subdirectories/files would not inherit its parent's context if
it had been set explicitly to a non-default value (other than the genfs
context specified by the policy). This can be reproduced as follows (on
Fedora/RHEL):
# mkdir /sys/fs/cgroup/unified/test
# # Need permissive to change the label under Fedora policy:
# setenforce 0
# chcon -t container_file_t /sys/fs/cgroup/unified/test
# ls -lZ /sys/fs/cgroup/unified
total 0
-r--r--r--. 1 root root system_u:object_r:cgroup_t:s0 0 Jan 29 03:06 cgroup.controllers
-rw-r--r--. 1 root root system_u:object_r:cgroup_t:s0 0 Jan 29 03:06 cgroup.max.depth
-rw-r--r--. 1 root root system_u:object_r:cgroup_t:s0 0 Jan 29 03:06 cgroup.max.descendants
-rw-r--r--. 1 root root system_u:object_r:cgroup_t:s0 0 Jan 29 03:06 cgroup.procs
-r--r--r--. 1 root root system_u:object_r:cgroup_t:s0 0 Jan 29 03:06 cgroup.stat
-rw-r--r--. 1 root root system_u:object_r:cgroup_t:s0 0 Jan 29 03:06 cgroup.subtree_control
-rw-r--r--. 1 root root system_u:object_r:cgroup_t:s0 0 Jan 29 03:06 cgroup.threads
drwxr-xr-x. 2 root root system_u:object_r:cgroup_t:s0 0 Jan 29 03:06 init.scope
drwxr-xr-x. 26 root root system_u:object_r:cgroup_t:s0 0 Jan 29 03:21 system.slice
drwxr-xr-x. 3 root root system_u:object_r:container_file_t:s0 0 Jan 29 03:15 test
drwxr-xr-x. 3 root root system_u:object_r:cgroup_t:s0 0 Jan 29 03:06 user.slice
# mkdir /sys/fs/cgroup/unified/test/subdir
Actual result:
# ls -ldZ /sys/fs/cgroup/unified/test/subdir
drwxr-xr-x. 2 root root system_u:object_r:cgroup_t:s0 0 Jan 29 03:15 /sys/fs/cgroup/unified/test/subdir
Expected result:
# ls -ldZ /sys/fs/cgroup/unified/test/subdir
drwxr-xr-x. 2 root root unconfined_u:object_r:container_file_t:s0 0 Jan 29 03:15 /sys/fs/cgroup/unified/test/subdir
Link: https://github.com/SELinuxProject/selinux-kernel/issues/39
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
This patch introduces a new security hook that is intended for
initializing the security data for newly created kernfs nodes, which
provide a way of storing a non-default security context, but need to
operate independently from mounts (and therefore may not have an
associated inode at the moment of creation).
The main motivation is to allow kernfs nodes to inherit the context of
the parent under SELinux, similar to the behavior of
security_inode_init_security(). Other LSMs may implement their own logic
for handling the creation of new nodes.
This patch also adds helper functions to <linux/kernfs.h> for
getting/setting security xattrs of a kernfs node so that LSMs hooks are
able to do their job. Other important attributes should be accessible
direcly in the kernfs_node fields (in case there is need for more, then
new helpers should be added to kernfs.h along with the patch that needs
them).
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: more manual merge fixes]
Signed-off-by: Paul Moore <paul@paul-moore.com>
Replace the special handling of security xattrs with simple_xattrs, as
is already done for the trusted xattrs. This simplifies the code and
allows LSMs to use more than just a single xattr to do their business.
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: manual merge fixes]
Signed-off-by: Paul Moore <paul@paul-moore.com>
This is a read-only operation, so we can simply return -ENODATA if
kn->iattr is NULL.
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: minor merge fixes]
Signed-off-by: Paul Moore <paul@paul-moore.com>
Right now, kernfs_iattrs embeds the whole struct iattr, even though it
doesn't really use half of its fields... This both leads to wasting
space and makes the code look awkward. Let's just list the few fields
we need directly in struct kernfs_iattrs.
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: merged a number of chunks manually due to fuzz]
Signed-off-by: Paul Moore <paul@paul-moore.com>
Pull vfs mount infrastructure updates from Al Viro:
"The rest of core infrastructure; no new syscalls in that pile, but the
old parts are switched to new infrastructure. At that point
conversions of individual filesystems can happen independently; some
are done here (afs, cgroup, procfs, etc.), there's also a large series
outside of that pile dealing with NFS (quite a bit of option-parsing
stuff is getting used there - it's one of the most convoluted
filesystems in terms of mount-related logics), but NFS bits are the
next cycle fodder.
It got seriously simplified since the last cycle; documentation is
probably the weakest bit at the moment - I considered dropping the
commit introducing Documentation/filesystems/mount_api.txt (cutting
the size increase by quarter ;-), but decided that it would be better
to fix it up after -rc1 instead.
That pile allows to do followup work in independent branches, which
should make life much easier for the next cycle. fs/super.c size
increase is unpleasant; there's a followup series that allows to
shrink it considerably, but I decided to leave that until the next
cycle"
* 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (41 commits)
afs: Use fs_context to pass parameters over automount
afs: Add fs_context support
vfs: Add some logging to the core users of the fs_context log
vfs: Implement logging through fs_context
vfs: Provide documentation for new mount API
vfs: Remove kern_mount_data()
hugetlbfs: Convert to fs_context
cpuset: Use fs_context
kernfs, sysfs, cgroup, intel_rdt: Support fs_context
cgroup: store a reference to cgroup_ns into cgroup_fs_context
cgroup1_get_tree(): separate "get cgroup_root to use" into a separate helper
cgroup_do_mount(): massage calling conventions
cgroup: stash cgroup_root reference into cgroup_fs_context
cgroup2: switch to option-by-option parsing
cgroup1: switch to option-by-option parsing
cgroup: take options parsing into ->parse_monolithic()
cgroup: fold cgroup1_mount() into cgroup1_get_tree()
cgroup: start switching to fs_context
ipc: Convert mqueue fs to fs_context
proc: Add fs_context support to procfs
...
Here is the big driver core patchset for 5.1-rc1
More patches than "normal" here this merge window, due to some work in
the driver core by Alexander Duyck to rework the async probe
functionality to work better for a number of devices, and independant
work from Rafael for the device link functionality to make it work
"correctly".
Also in here is:
- lots of BUS_ATTR() removals, the macro is about to go away
- firmware test fixups
- ihex fixups and simplification
- component additions (also includes i915 patches)
- lots of minor coding style fixups and cleanups.
All of these have been in linux-next for a while with no reported
issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core updates from Greg KH:
"Here is the big driver core patchset for 5.1-rc1
More patches than "normal" here this merge window, due to some work in
the driver core by Alexander Duyck to rework the async probe
functionality to work better for a number of devices, and independant
work from Rafael for the device link functionality to make it work
"correctly".
Also in here is:
- lots of BUS_ATTR() removals, the macro is about to go away
- firmware test fixups
- ihex fixups and simplification
- component additions (also includes i915 patches)
- lots of minor coding style fixups and cleanups.
All of these have been in linux-next for a while with no reported
issues"
* tag 'driver-core-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (65 commits)
driver core: platform: remove misleading err_alloc label
platform: set of_node in platform_device_register_full()
firmware: hardcode the debug message for -ENOENT
driver core: Add missing description of new struct device_link field
driver core: Fix PM-runtime for links added during consumer probe
drivers/component: kerneldoc polish
async: Add cmdline option to specify drivers to be async probed
driver core: Fix possible supplier PM-usage counter imbalance
PM-runtime: Fix __pm_runtime_set_status() race with runtime resume
driver: platform: Support parsing GpioInt 0 in platform_get_irq()
selftests: firmware: fix verify_reqs() return value
Revert "selftests: firmware: remove use of non-standard diff -Z option"
Revert "selftests: firmware: add CONFIG_FW_LOADER_USER_HELPER_FALLBACK to config"
device: Fix comment for driver_data in struct device
kernfs: Allocating memory for kernfs_iattrs with kmem_cache.
sysfs: remove unused include of kernfs-internal.h
driver core: Postpone DMA tear-down until after devres release
driver core: Document limitation related to DL_FLAG_RPM_ACTIVE
PM-runtime: Take suppliers into account in __pm_runtime_set_status()
device.h: Add __cold to dev_<level> logging functions
...
Patch series "psi: pressure stall monitors", v3.
Android is adopting psi to detect and remedy memory pressure that
results in stuttering and decreased responsiveness on mobile devices.
Psi gives us the stall information, but because we're dealing with
latencies in the millisecond range, periodically reading the pressure
files to detect stalls in a timely fashion is not feasible. Psi also
doesn't aggregate its averages at a high enough frequency right now.
This patch series extends the psi interface such that users can
configure sensitive latency thresholds and use poll() and friends to be
notified when these are breached.
As high-frequency aggregation is costly, it implements an aggregation
method that is optimized for fast, short-interval averaging, and makes
the aggregation frequency adaptive, such that high-frequency updates
only happen while monitored stall events are actively occurring.
With these patches applied, Android can monitor for, and ward off,
mounting memory shortages before they cause problems for the user. For
example, using memory stall monitors in userspace low memory killer
daemon (lmkd) we can detect mounting pressure and kill less important
processes before device becomes visibly sluggish.
In our memory stress testing psi memory monitors produce roughly 10x
less false positives compared to vmpressure signals. Having ability to
specify multiple triggers for the same psi metric allows other parts of
Android framework to monitor memory state of the device and act
accordingly.
The new interface is straightforward. The user opens one of the
pressure files for writing and writes a trigger description into the
file descriptor that defines the stall state - some or full, and the
maximum stall time over a given window of time. E.g.:
/* Signal when stall time exceeds 100ms of a 1s window */
char trigger[] = "full 100000 1000000";
fd = open("/proc/pressure/memory");
write(fd, trigger, sizeof(trigger));
while (poll() >= 0) {
...
}
close(fd);
When the monitored stall state is entered, psi adapts its aggregation
frequency according to what the configured time window requires in order
to emit event signals in a timely fashion. Once the stalling subsides,
aggregation reverts back to normal.
The trigger is associated with the open file descriptor. To stop
monitoring, the user only needs to close the file descriptor and the
trigger is discarded.
Patches 1-4 prepare the psi code for polling support. Patch 5
implements the adaptive polling logic, the pressure growth detection
optimized for short intervals, and hooks up write() and poll() on the
pressure files.
The patches were developed in collaboration with Johannes Weiner.
This patch (of 5):
Kernfs has a standardized poll/notification mechanism for waking all
pollers on all fds when a filesystem node changes. To allow polling for
custom events, add a .poll callback that can override the default.
This is in preparation for pollable cgroup pressure files which have
per-fd trigger configurations.
Link: http://lkml.kernel.org/r/20190124211518.244221-2-surenb@google.com
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make kernfs support superblock creation/mount/remount with fs_context.
This requires that sysfs, cgroup and intel_rdt, which are built on kernfs,
be made to support fs_context also.
Notes:
(1) A kernfs_fs_context struct is created to wrap fs_context and the
kernfs mount parameters are moved in here (or are in fs_context).
(2) kernfs_mount{,_ns}() are made into kernfs_get_tree(). The extra
namespace tag parameter is passed in the context if desired
(3) kernfs_free_fs_context() is provided as a destructor for the
kernfs_fs_context struct, but for the moment it does nothing except
get called in the right places.
(4) sysfs doesn't wrap kernfs_fs_context since it has no parameters to
pass, but possibly this should be done anyway in case someone wants to
add a parameter in future.
(5) A cgroup_fs_context struct is created to wrap kernfs_fs_context and
the cgroup v1 and v2 mount parameters are all moved there.
(6) cgroup1 parameter parsing error messages are now handled by invalf(),
which allows userspace to collect them directly.
(7) cgroup1 parameter cleanup is now done in the context destructor rather
than in the mount/get_tree and remount functions.
Weirdies:
(*) cgroup_do_get_tree() calls cset_cgroup_from_root() with locks held,
but then uses the resulting pointer after dropping the locks. I'm
told this is okay and needs commenting.
(*) The cgroup refcount web. This really needs documenting.
(*) cgroup2 only has one root?
Add a suggestion from Thomas Gleixner in which the RDT enablement code is
placed into its own function.
[folded a leak fix from Andrey Vagin]
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cc: Tejun Heo <tj@kernel.org>
cc: Li Zefan <lizefan@huawei.com>
cc: Johannes Weiner <hannes@cmpxchg.org>
cc: cgroups@vger.kernel.org
cc: fenghua.yu@intel.com
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Creating a new cache for kernfs_iattrs.
Currently, memory is allocated with kzalloc() which
always gives aligned memory. On ARM, this is 64 byte aligned.
To avoid the wastage of memory in aligning the size requested,
a new cache for kernfs_iattrs is created.
Size of struct kernfs_iattrs is 80 Bytes.
On ARM, it will come in kmalloc-128 slab.
and it will come in kmalloc-192 slab if debug info is enabled.
Extra bytes taken 48 bytes.
Total number of objects created : 4096
Total saving = 48*4096 = 192 KB
After creating new slab(When debug info is enabled) :
sh-3.2# cat /proc/slabinfo
...
kernfs_iattrs_cache 4069 4096 128 32 1 : tunables 0 0 0 : slabdata 128 128 0
...
All testing has been done on ARM target.
Signed-off-by: Ayush Mittal <ayush.m@samsung.com>
Signed-off-by: Vaneet Narang <v.narang@samsung.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
same story as with last May fixes in sysfs (7b745a4e40
"unfuck sysfs_mount()"); new_sb is left uninitialized
in case of early errors in kernfs_mount_ns() and papering
over it by treating any error from kernfs_mount_ns() as
equivalent to !new_ns ends up conflating the cases when
objects had never been transferred to a superblock with
ones when that has happened and resulting new superblock
had been dropped. Easily fixed (same way as in sysfs
case). Additionally, there's a superblock leak on
kernfs_node_dentry() failure *and* a dentry leak inside
kernfs_node_dentry() itself - the latter on probably
impossible errors, but the former not impossible to trigger
(as the matter of fact, injecting allocation failures
at that point *does* trigger it).
Cc: stable@kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
kernfs_notify() does two notifications: poll and fsnotify. Originally,
both notifications were done from scheduled work context and all that
kernfs_notify() did was schedule the work.
This patch simply moves the poll notification from the scheduled work
handler to kernfs_notify(). The fsnotify notification still needs to be
done from scheduled work context because it can sleep (it needs to lock
a mutex).
If the poll notification is time critical (the notified thread needs to
wake as quickly as possible), it's better to do it from kernfs_notify()
directly. One example is calling sysfs_notify_dirent() from a hardware
interrupt handler to wake up a thread and handle the interrupt in user
space.
Signed-off-by: Radu Rendec <radu.rendec@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The page cache and most shrinkable slab caches hold data that has been
read from disk, but there are some caches that only cache CPU work, such
as the dentry and inode caches of procfs and sysfs, as well as the subset
of radix tree nodes that track non-resident page cache.
Currently, all these are shrunk at the same rate: using DEFAULT_SEEKS for
the shrinker's seeks setting tells the reclaim algorithm that for every
two page cache pages scanned it should scan one slab object.
This is a bogus setting. A virtual inode that required no IO to create is
not twice as valuable as a page cache page; shadow cache entries with
eviction distances beyond the size of memory aren't either.
In most cases, the behavior in practice is still fine. Such virtual
caches don't tend to grow and assert themselves aggressively, and usually
get picked up before they cause problems. But there are scenarios where
that's not true.
Our database workloads suffer from two of those. For one, their file
workingset is several times bigger than available memory, which has the
kernel aggressively create shadow page cache entries for the non-resident
parts of it. The workingset code does tell the VM that most of these are
expendable, but the VM ends up balancing them 2:1 to cache pages as per
the seeks setting. This is a huge waste of memory.
These workloads also deal with tens of thousands of open files and use
/proc for introspection, which ends up growing the proc_inode_cache to
absurdly large sizes - again at the cost of valuable cache space, which
isn't a reasonable trade-off, given that proc inodes can be re-created
without involving the disk.
This patch implements a "zero-seek" setting for shrinkers that results in
a target ratio of 0:1 between their objects and IO-backed caches. This
allows such virtual caches to grow when memory is available (they do
cache/avoid CPU work after all), but effectively disables them as soon as
IO-backed objects are under pressure.
It then switches the shrinkers for procfs and sysfs metadata, as well as
excess page cache shadow nodes, to the new zero-seek setting.
Link: http://lkml.kernel.org/r/20181009184732.762-5-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Domas Mituzas <dmituzas@fb.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Rik van Riel <riel@surriel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The terminating NUL byte is only there because the buffer is
allocated with kzalloc(PAGE_SIZE, GFP_KERNEL), but since the
range-check is off-by-one, and PAGE_SIZE==PATH_MAX, the
returned string may not be zero-terminated if it is exactly
PATH_MAX characters long. Furthermore also the initial loop
may theoretically exceed PATH_MAX and cause a fault.
Signed-off-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here are all of the driver core and related patches for 4.19-rc1.
Nothing huge here, just a number of small cleanups and the ability to
now stop the deferred probing after init happens.
All of these have been in linux-next for a while with only a merge issue
reported. That merge issue is in fs/sysfs/group.c and Stephen has
posted the diff of what it should be to resolve this. I'll follow up
with that diff to this pull request.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core updates from Greg KH:
"Here are all of the driver core and related patches for 4.19-rc1.
Nothing huge here, just a number of small cleanups and the ability to
now stop the deferred probing after init happens.
All of these have been in linux-next for a while with only a merge
issue reported"
* tag 'driver-core-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (21 commits)
base: core: Remove WARN_ON from link dependencies check
drivers/base: stop new probing during shutdown
drivers: core: Remove glue dirs from sysfs earlier
driver core: remove unnecessary function extern declare
sysfs.h: fix non-kernel-doc comment
PM / Domains: Stop deferring probe at the end of initcall
iommu: Remove IOMMU_OF_DECLARE
iommu: Stop deferring probe at end of initcalls
pinctrl: Support stopping deferred probe after initcalls
dt-bindings: pinctrl: add a 'pinctrl-use-default' property
driver core: allow stopping deferred probe after init
driver core: add a debugfs entry to show deferred devices
sysfs: Fix internal_create_group() for named group updates
base: fix order of OF initialization
linux/device.h: fix kernel-doc notation warning
Documentation: update firmware loader fallback reference
kobject: Replace strncpy with memcpy
drivers: base: cacheinfo: use OF property_read_u32 instead of get_property,read_number
kernfs: Replace strncpy with memcpy
device: Add #define dev_fmt similar to #define pr_fmt
...
This change allows creating kernfs files and directories with arbitrary
uid/gid instead of always using GLOBAL_ROOT_UID/GID by extending
kernfs_create_dir_ns() and kernfs_create_file_ns() with uid/gid arguments.
The "simple" kernfs_create_file() and kernfs_create_dir() are left alone
and always create objects belonging to the global root.
When creating symlinks ownership (uid/gid) is taken from the target kernfs
object.
Co-Developed-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
gcc 8.1.0 complains:
fs/kernfs/symlink.c:91:3: warning:
'strncpy' output truncated before terminating nul copying
as many bytes from a string as its length
fs/kernfs/symlink.c: In function 'kernfs_iop_get_link':
fs/kernfs/symlink.c:88:14: note: length computed here
Using strncpy() is indeed less than perfect since the length of data to
be copied has already been determined with strlen(). Replace strncpy()
with memcpy() to address the warning and optimize the code a little.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This is a late set of changes from Deepa Dinamani doing an automated
treewide conversion of the inode and iattr structures from 'timespec'
to 'timespec64', to push the conversion from the VFS layer into the
individual file systems.
There were no conflicts between this and the contents of linux-next
until just before the merge window, when we saw multiple problems:
- A minor conflict with my own y2038 fixes, which I could address
by adding another patch on top here.
- One semantic conflict with late changes to the NFS tree. I addressed
this by merging Deepa's original branch on top of the changes that
now got merged into mainline and making sure the merge commit includes
the necessary changes as produced by coccinelle.
- A trivial conflict against the removal of staging/lustre.
- Multiple conflicts against the VFS changes in the overlayfs tree.
These are still part of linux-next, but apparently this is no longer
intended for 4.18 [1], so I am ignoring that part.
As Deepa writes:
The series aims to switch vfs timestamps to use struct timespec64.
Currently vfs uses struct timespec, which is not y2038 safe.
The series involves the following:
1. Add vfs helper functions for supporting struct timepec64 timestamps.
2. Cast prints of vfs timestamps to avoid warnings after the switch.
3. Simplify code using vfs timestamps so that the actual
replacement becomes easy.
4. Convert vfs timestamps to use struct timespec64 using a script.
This is a flag day patch.
Next steps:
1. Convert APIs that can handle timespec64, instead of converting
timestamps at the boundaries.
2. Update internal data structures to avoid timestamp conversions.
Thomas Gleixner adds:
I think there is no point to drag that out for the next merge window.
The whole thing needs to be done in one go for the core changes which
means that you're going to play that catchup game forever. Let's get
over with it towards the end of the merge window.
[1] https://www.spinics.net/lists/linux-fsdevel/msg128294.html
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Merge tag 'vfs-timespec64' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground
Pull inode timestamps conversion to timespec64 from Arnd Bergmann:
"This is a late set of changes from Deepa Dinamani doing an automated
treewide conversion of the inode and iattr structures from 'timespec'
to 'timespec64', to push the conversion from the VFS layer into the
individual file systems.
As Deepa writes:
'The series aims to switch vfs timestamps to use struct timespec64.
Currently vfs uses struct timespec, which is not y2038 safe.
The series involves the following:
1. Add vfs helper functions for supporting struct timepec64
timestamps.
2. Cast prints of vfs timestamps to avoid warnings after the switch.
3. Simplify code using vfs timestamps so that the actual replacement
becomes easy.
4. Convert vfs timestamps to use struct timespec64 using a script.
This is a flag day patch.
Next steps:
1. Convert APIs that can handle timespec64, instead of converting
timestamps at the boundaries.
2. Update internal data structures to avoid timestamp conversions'
Thomas Gleixner adds:
'I think there is no point to drag that out for the next merge
window. The whole thing needs to be done in one go for the core
changes which means that you're going to play that catchup game
forever. Let's get over with it towards the end of the merge window'"
* tag 'vfs-timespec64' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground:
pstore: Remove bogus format string definition
vfs: change inode times to use struct timespec64
pstore: Convert internal records to timespec64
udf: Simplify calls to udf_disk_stamp_to_time
fs: nfs: get rid of memcpys for inode times
ceph: make inode time prints to be long long
lustre: Use long long type to print inode time
fs: add timespec64_truncate()
Pull the timespec64 conversion from Deepa Dinamani:
"The series aims to switch vfs timestamps to use
struct timespec64. Currently vfs uses struct timespec,
which is not y2038 safe.
The flag patch applies cleanly. I've not seen the timestamps
update logic change often. The series applies cleanly on 4.17-rc6
and linux-next tip (top commit: next-20180517).
I'm not sure how to merge this kind of a series with a flag patch.
We are targeting 4.18 for this.
Let me know if you have other suggestions.
The series involves the following:
1. Add vfs helper functions for supporting struct timepec64 timestamps.
2. Cast prints of vfs timestamps to avoid warnings after the switch.
3. Simplify code using vfs timestamps so that the actual
replacement becomes easy.
4. Convert vfs timestamps to use struct timespec64 using a script.
This is a flag day patch.
I've tried to keep the conversions with the script simple, to
aid in the reviews. I've kept all the internal filesystem data
structures and function signatures the same.
Next steps:
1. Convert APIs that can handle timespec64, instead of converting
timestamps at the boundaries.
2. Update internal data structures to avoid timestamp conversions."
I've pulled it into a branch based on top of the NFS changes that
are now in mainline, so I could resolve the non-obvious conflict
between the two while merging.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Here is the driver core patchset for 4.18-rc1.
The large chunk of these are firmware core documentation and api
updates. Nothing major there, just better descriptions for others to be
able to understand the firmware code better. There's also a user for a
new firmware api call.
Other than that, there are some minor updates for debugfs, kernfs, and
the driver core itself.
All of these have been in linux-next for a while with no reported
issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core updates from Greg KH:
"Here is the driver core patchset for 4.18-rc1.
The large chunk of these are firmware core documentation and api
updates. Nothing major there, just better descriptions for others to
be able to understand the firmware code better. There's also a user
for a new firmware api call.
Other than that, there are some minor updates for debugfs, kernfs, and
the driver core itself.
All of these have been in linux-next for a while with no reported
issues"
* tag 'driver-core-4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (23 commits)
driver core: hold dev's parent lock when needed
driver-core: return EINVAL error instead of BUG_ON()
driver core: add __printf verification to device_create_groups_vargs
mm: memory_hotplug: use put_device() if device_register fail
base: core: fix typo 'can by' to 'can be'
debugfs: inode: debugfs_create_dir uses mode permission from parent
debugfs: Re-use kstrtobool_from_user()
Documentation: clarify firmware_class provenance and why we can't rename the module
Documentation: remove stale firmware API reference
Documentation: fix few typos and clarifications for the firmware loader
ath10k: re-enable the firmware fallback mechanism for testmode
ath10k: use firmware_request_nowarn() to load firmware
firmware: add firmware_request_nowarn() - load firmware without warnings
firmware_loader: make firmware_fallback_sysfs() print more useful
firmware_loader: move kconfig FW_LOADER entries to its own file
firmware_loader: replace ---help--- with help
firmware_loader: enhance Kconfig documentation over FW_LOADER
firmware_loader: document firmware_sysfs_fallback()
firmware: rename fw_sysfs_fallback to firmware_fallback_sysfs()
firmware: use () to terminate kernel-doc function names
...
Use new return type vm_fault_t for page_mkwrite and
fault handler. For now, this is just documenting that
the function returns a VM_FAULT value rather than an
errno. Once all instances are converted, vm_fault_t
will become a distinct type.
Reference id -> 1c8f422059 ("mm: change return type to
vm_fault_t")
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:
for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
done
with de-mangling cleanups yet to come.
NOTE! On almost all architectures, the EPOLL* constants have the same
values as the POLL* constants do. But they keyword here is "almost".
For various bad reasons they aren't the same, and epoll() doesn't
actually work quite correctly in some cases due to this on Sparc et al.
The next patch from Al will sort out the final differences, and we
should be all done.
Scripted-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull misc vfs fixes from Al Viro.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
seq_file: fix incomplete reset on read from zero offset
kernfs: fix regression in kernfs_fop_write caused by wrong type
Pull poll annotations from Al Viro:
"This introduces a __bitwise type for POLL### bitmap, and propagates
the annotations through the tree. Most of that stuff is as simple as
'make ->poll() instances return __poll_t and do the same to local
variables used to hold the future return value'.
Some of the obvious brainos found in process are fixed (e.g. POLLIN
misspelled as POLL_IN). At that point the amount of sparse warnings is
low and most of them are for genuine bugs - e.g. ->poll() instance
deciding to return -EINVAL instead of a bitmap. I hadn't touched those
in this series - it's large enough as it is.
Another problem it has caught was eventpoll() ABI mess; select.c and
eventpoll.c assumed that corresponding POLL### and EPOLL### were
equal. That's true for some, but not all of them - EPOLL### are
arch-independent, but POLL### are not.
The last commit in this series separates userland POLL### values from
the (now arch-independent) kernel-side ones, converting between them
in the few places where they are copied to/from userland. AFAICS, this
is the least disruptive fix preserving poll(2) ABI and making epoll()
work on all architectures.
As it is, it's simply broken on sparc - try to give it EPOLLWRNORM and
it will trigger only on what would've triggered EPOLLWRBAND on other
architectures. EPOLLWRBAND and EPOLLRDHUP, OTOH, are never triggered
at all on sparc. With this patch they should work consistently on all
architectures"
* 'misc.poll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (37 commits)
make kernel-side POLL... arch-independent
eventpoll: no need to mask the result of epi_item_poll() again
eventpoll: constify struct epoll_event pointers
debugging printk in sg_poll() uses %x to print POLL... bitmap
annotate poll(2) guts
9p: untangle ->poll() mess
->si_band gets POLL... bitmap stored into a user-visible long field
ring_buffer_poll_wait() return value used as return value of ->poll()
the rest of drivers/*: annotate ->poll() instances
media: annotate ->poll() instances
fs: annotate ->poll() instances
ipc, kernel, mm: annotate ->poll() instances
net: annotate ->poll() instances
apparmor: annotate ->poll() instances
tomoyo: annotate ->poll() instances
sound: annotate ->poll() instances
acpi: annotate ->poll() instances
crypto: annotate ->poll() instances
block: annotate ->poll() instances
x86: annotate ->poll() instances
...
Commit b7ce40cff0 ("kernfs: cache atomic_write_len in
kernfs_open_file") changes type of local variable 'len' from ssize_t
to size_t. This change caused that the *ppos value is updated also
when the previous write callback failed.
Mentioned snippet:
...
len = ops->write(...); <- return value can be negative
...
if (len > 0) <- true here in this case
*ppos += len;
...
Fixes: b7ce40cff0 ("kernfs: cache atomic_write_len in kernfs_open_file")
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This is a pure automated search-and-replace of the internal kernel
superblock flags.
The s_flags are now called SB_*, with the names and the values for the
moment mirroring the MS_* flags that they're equivalent to.
Note how the MS_xyz flags are the ones passed to the mount system call,
while the SB_xyz flags are what we then use in sb->s_flags.
The script to do this was:
# places to look in; re security/*: it generally should *not* be
# touched (that stuff parses mount(2) arguments directly), but
# there are two places where we really deal with superblock flags.
FILES="drivers/mtd drivers/staging/lustre fs ipc mm \
include/linux/fs.h include/uapi/linux/bfs_fs.h \
security/apparmor/apparmorfs.c security/apparmor/include/lib.h"
# the list of MS_... constants
SYMS="RDONLY NOSUID NODEV NOEXEC SYNCHRONOUS REMOUNT MANDLOCK \
DIRSYNC NOATIME NODIRATIME BIND MOVE REC VERBOSE SILENT \
POSIXACL UNBINDABLE PRIVATE SLAVE SHARED RELATIME KERNMOUNT \
I_VERSION STRICTATIME LAZYTIME SUBMOUNT NOREMOTELOCK NOSEC BORN \
ACTIVE NOUSER"
SED_PROG=
for i in $SYMS; do SED_PROG="$SED_PROG -e s/MS_$i/SB_$i/g"; done
# we want files that contain at least one of MS_...,
# with fs/namespace.c and fs/pnode.c excluded.
L=$(for i in $SYMS; do git grep -w -l MS_$i $FILES; done| sort|uniq|grep -v '^fs/namespace.c'|grep -v '^fs/pnode.c')
for f in $L; do sed -i $f $SED_PROG; done
Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull block layer updates from Jens Axboe:
"This is the first pull request for 4.14, containing most of the code
changes. It's a quiet series this round, which I think we needed after
the churn of the last few series. This contains:
- Fix for a registration race in loop, from Anton Volkov.
- Overflow complaint fix from Arnd for DAC960.
- Series of drbd changes from the usual suspects.
- Conversion of the stec/skd driver to blk-mq. From Bart.
- A few BFQ improvements/fixes from Paolo.
- CFQ improvement from Ritesh, allowing idling for group idle.
- A few fixes found by Dan's smatch, courtesy of Dan.
- A warning fixup for a race between changing the IO scheduler and
device remova. From David Jeffery.
- A few nbd fixes from Josef.
- Support for cgroup info in blktrace, from Shaohua.
- Also from Shaohua, new features in the null_blk driver to allow it
to actually hold data, among other things.
- Various corner cases and error handling fixes from Weiping Zhang.
- Improvements to the IO stats tracking for blk-mq from me. Can
drastically improve performance for fast devices and/or big
machines.
- Series from Christoph removing bi_bdev as being needed for IO
submission, in preparation for nvme multipathing code.
- Series from Bart, including various cleanups and fixes for switch
fall through case complaints"
* 'for-4.14/block' of git://git.kernel.dk/linux-block: (162 commits)
kernfs: checking for IS_ERR() instead of NULL
drbd: remove BIOSET_NEED_RESCUER flag from drbd_{md_,}io_bio_set
drbd: Fix allyesconfig build, fix recent commit
drbd: switch from kmalloc() to kmalloc_array()
drbd: abort drbd_start_resync if there is no connection
drbd: move global variables to drbd namespace and make some static
drbd: rename "usermode_helper" to "drbd_usermode_helper"
drbd: fix race between handshake and admin disconnect/down
drbd: fix potential deadlock when trying to detach during handshake
drbd: A single dot should be put into a sequence.
drbd: fix rmmod cleanup, remove _all_ debugfs entries
drbd: Use setup_timer() instead of init_timer() to simplify the code.
drbd: fix potential get_ldev/put_ldev refcount imbalance during attach
drbd: new disk-option disable-write-same
drbd: Fix resource role for newly created resources in events2
drbd: mark symbols static where possible
drbd: Send P_NEG_ACK upon write error in protocol != C
drbd: add explicit plugging when submitting batches
drbd: change list_for_each_safe to while(list_first_entry_or_null)
drbd: introduce drbd_recv_header_maybe_unplug
...
The reference count in kernfs_node structure is treated like a rwsem by
using lockdep instrumentation code. The lockdep name, however, is still
"s_active" which is carried over from the old sysfs code. As s_active
is no longer the variable name, its use may confuse users on where the
lock is when it is reported by lockdep. So it is changed to "kn->count"
which is how this variable is normally referenced in kernfs code.
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
By default we output cgroup id in blktrace. This adds an option to
display cgroup path. Since get cgroup path is a relativly heavy
operation, we don't enable it by default.
with the option enabled, blktrace will output something like this:
dd-1353 [007] d..2 293.015252: 8,0 /test/level D R 24 + 8 [dd]
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Now we have the facilities to implement exportfs operations. The idea is
cgroup can export the fhandle info to userspace, then userspace uses
fhandle to find the cgroup name. Another example is userspace can get
fhandle for a cgroup and BPF uses the fhandle to filter info for the
cgroup.
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
inode number and generation can identify a kernfs node. We are going to
export the identification by exportfs operations, so put ino and
generation into a separate structure. It's convenient when later patches
use the identification.
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When working on adding exportfs operations in kernfs, I found it's hard
to initialize dentry->d_fsdata in the exportfs operations. Looks there
is no way to do it without race condition. Look at the kernfs code
closely, there is no point to set dentry->d_fsdata. inode->i_private
already points to kernfs_node, and we can get inode from a dentry. So
this patch just delete the d_fsdata usage.
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add an API to get kernfs node from inode number. We will need this to
implement exportfs operations.
This API will be used in blktrace too later, so it should be as fast as
possible. To make the API lock free, kernfs node is freed in RCU
context. And we depend on kernfs_node count/ino number to filter out
stale kernfs nodes.
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Set i_generation for kernfs inode. This is required to implement
exportfs operations. The generation is 32-bit, so it's possible the
generation wraps up and we find stale files. To reduce the posssibility,
we don't reuse inode numer immediately. When the inode number allocation
wraps, we increase generation number. In this way generation/inode
number consist of a 64-bit number which is unlikely duplicated. This
does make the idr tree more sparse and waste some memory. Since idr
manages 32-bit keys, idr uses a 6-level radix tree, each level covers 6
bits of the key. In a 100k inode kernfs, the worst case will have around
300k radix tree node. Each node is 576bytes, so the tree will use about
~150M memory. Sounds not too bad, if this really is a problem, we should
find better data structure.
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
kernfs uses ida to manage inode number. The problem is we can't get
kernfs_node from inode number with ida. Switching to use idr, next patch
will add an API to get kernfs_node from inode number.
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Recently started seeing a kernel oops when a module tries removing a
memory mapped sysfs bin_attribute. On closer investigation the root
cause seems to be kernfs_release_file() trying to call
kernfs_op.release() callback that's NULL for such sysfs
bin_attributes. The oops occurs when kernfs_release_file() is called from
kernfs_drain_open_files() to cleanup any open handles with active
memory mappings.
The patch fixes this by checking for flag KERNFS_HAS_RELEASE before
calling kernfs_release_file() in function kernfs_drain_open_files().
On ppc64-le arch with cxl module the oops back-trace is of the
form below:
[ 861.381126] Unable to handle kernel paging request for instruction fetch
[ 861.381360] Faulting instruction address: 0x00000000
[ 861.381428] Oops: Kernel access of bad area, sig: 11 [#1]
....
[ 861.382481] NIP: 0000000000000000 LR: c000000000362c60 CTR:
0000000000000000
....
Call Trace:
[c000000f1680b750] [c000000000362c34] kernfs_drain_open_files+0x104/0x1d0 (unreliable)
[c000000f1680b790] [c00000000035fa00] __kernfs_remove+0x260/0x2c0
[c000000f1680b820] [c000000000360da0] kernfs_remove_by_name_ns+0x60/0xe0
[c000000f1680b8b0] [c0000000003638f4] sysfs_remove_bin_file+0x24/0x40
[c000000f1680b8d0] [c00000000062a164] device_remove_bin_file+0x24/0x40
[c000000f1680b8f0] [d000000009b7b22c] cxl_sysfs_afu_remove+0x144/0x170 [cxl]
[c000000f1680b940] [d000000009b7c7e4] cxl_remove+0x6c/0x1a0 [cxl]
[c000000f1680b990] [c00000000052f694] pci_device_remove+0x64/0x110
[c000000f1680b9d0] [c0000000006321d4] device_release_driver_internal+0x1f4/0x2b0
[c000000f1680ba20] [c000000000525cb0] pci_stop_bus_device+0xa0/0xd0
[c000000f1680ba60] [c000000000525e80] pci_stop_and_remove_bus_device+0x20/0x40
[c000000f1680ba90] [c00000000004a6c4] pci_hp_remove_devices+0x84/0xc0
[c000000f1680bad0] [c00000000004a688] pci_hp_remove_devices+0x48/0xc0
[c000000f1680bb10] [c0000000009dfda4] eeh_reset_device+0xb0/0x290
[c000000f1680bbb0] [c000000000032b4c] eeh_handle_normal_event+0x47c/0x530
[c000000f1680bc60] [c000000000032e64] eeh_handle_event+0x174/0x350
[c000000f1680bd10] [c000000000033228] eeh_event_handler+0x1e8/0x1f0
[c000000f1680bdc0] [c0000000000d384c] kthread+0x14c/0x190
[c000000f1680be30] [c00000000000b5a0] ret_from_kernel_thread+0x5c/0xbc
Fixes: f83f3c5156 ("kernfs: fix locking around kernfs_ops->release() callback")
Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull vfs 'statx()' update from Al Viro.
This adds the new extended stat() interface that internally subsumes our
previous stat interfaces, and allows user mode to specify in more detail
what kind of information it wants.
It also allows for some explicit synchronization information to be
passed to the filesystem, which can be relevant for network filesystems:
is the cached value ok, or do you need open/close consistency, or what?
From David Howells.
Andreas Dilger points out that the first version of the extended statx
interface was posted June 29, 2010:
https://www.spinics.net/lists/linux-fsdevel/msg33831.html
* 'rebased-statx' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
statx: Add a system call to make enhanced file info available
Add a system call to make extended file information available, including
file creation and some attribute flags where available through the
underlying filesystem.
The getattr inode operation is altered to take two additional arguments: a
u32 request_mask and an unsigned int flags that indicate the
synchronisation mode. This change is propagated to the vfs_getattr*()
function.
Functions like vfs_stat() are now inline wrappers around new functions
vfs_statx() and vfs_statx_fd() to reduce stack usage.
========
OVERVIEW
========
The idea was initially proposed as a set of xattrs that could be retrieved
with getxattr(), but the general preference proved to be for a new syscall
with an extended stat structure.
A number of requests were gathered for features to be included. The
following have been included:
(1) Make the fields a consistent size on all arches and make them large.
(2) Spare space, request flags and information flags are provided for
future expansion.
(3) Better support for the y2038 problem [Arnd Bergmann] (tv_sec is an
__s64).
(4) Creation time: The SMB protocol carries the creation time, which could
be exported by Samba, which will in turn help CIFS make use of
FS-Cache as that can be used for coherency data (stx_btime).
This is also specified in NFSv4 as a recommended attribute and could
be exported by NFSD [Steve French].
(5) Lightweight stat: Ask for just those details of interest, and allow a
netfs (such as NFS) to approximate anything not of interest, possibly
without going to the server [Trond Myklebust, Ulrich Drepper, Andreas
Dilger] (AT_STATX_DONT_SYNC).
(6) Heavyweight stat: Force a netfs to go to the server, even if it thinks
its cached attributes are up to date [Trond Myklebust]
(AT_STATX_FORCE_SYNC).
And the following have been left out for future extension:
(7) Data version number: Could be used by userspace NFS servers [Aneesh
Kumar].
Can also be used to modify fill_post_wcc() in NFSD which retrieves
i_version directly, but has just called vfs_getattr(). It could get
it from the kstat struct if it used vfs_xgetattr() instead.
(There's disagreement on the exact semantics of a single field, since
not all filesystems do this the same way).
(8) BSD stat compatibility: Including more fields from the BSD stat such
as creation time (st_btime) and inode generation number (st_gen)
[Jeremy Allison, Bernd Schubert].
(9) Inode generation number: Useful for FUSE and userspace NFS servers
[Bernd Schubert].
(This was asked for but later deemed unnecessary with the
open-by-handle capability available and caused disagreement as to
whether it's a security hole or not).
(10) Extra coherency data may be useful in making backups [Andreas Dilger].
(No particular data were offered, but things like last backup
timestamp, the data version number and the DOS archive bit would come
into this category).
(11) Allow the filesystem to indicate what it can/cannot provide: A
filesystem can now say it doesn't support a standard stat feature if
that isn't available, so if, for instance, inode numbers or UIDs don't
exist or are fabricated locally...
(This requires a separate system call - I have an fsinfo() call idea
for this).
(12) Store a 16-byte volume ID in the superblock that can be returned in
struct xstat [Steve French].
(Deferred to fsinfo).
(13) Include granularity fields in the time data to indicate the
granularity of each of the times (NFSv4 time_delta) [Steve French].
(Deferred to fsinfo).
(14) FS_IOC_GETFLAGS value. These could be translated to BSD's st_flags.
Note that the Linux IOC flags are a mess and filesystems such as Ext4
define flags that aren't in linux/fs.h, so translation in the kernel
may be a necessity (or, possibly, we provide the filesystem type too).
(Some attributes are made available in stx_attributes, but the general
feeling was that the IOC flags were to ext[234]-specific and shouldn't
be exposed through statx this way).
(15) Mask of features available on file (eg: ACLs, seclabel) [Brad Boyer,
Michael Kerrisk].
(Deferred, probably to fsinfo. Finding out if there's an ACL or
seclabal might require extra filesystem operations).
(16) Femtosecond-resolution timestamps [Dave Chinner].
(A __reserved field has been left in the statx_timestamp struct for
this - if there proves to be a need).
(17) A set multiple attributes syscall to go with this.
===============
NEW SYSTEM CALL
===============
The new system call is:
int ret = statx(int dfd,
const char *filename,
unsigned int flags,
unsigned int mask,
struct statx *buffer);
The dfd, filename and flags parameters indicate the file to query, in a
similar way to fstatat(). There is no equivalent of lstat() as that can be
emulated with statx() by passing AT_SYMLINK_NOFOLLOW in flags. There is
also no equivalent of fstat() as that can be emulated by passing a NULL
filename to statx() with the fd of interest in dfd.
Whether or not statx() synchronises the attributes with the backing store
can be controlled by OR'ing a value into the flags argument (this typically
only affects network filesystems):
(1) AT_STATX_SYNC_AS_STAT tells statx() to behave as stat() does in this
respect.
(2) AT_STATX_FORCE_SYNC will require a network filesystem to synchronise
its attributes with the server - which might require data writeback to
occur to get the timestamps correct.
(3) AT_STATX_DONT_SYNC will suppress synchronisation with the server in a
network filesystem. The resulting values should be considered
approximate.
mask is a bitmask indicating the fields in struct statx that are of
interest to the caller. The user should set this to STATX_BASIC_STATS to
get the basic set returned by stat(). It should be noted that asking for
more information may entail extra I/O operations.
buffer points to the destination for the data. This must be 256 bytes in
size.
======================
MAIN ATTRIBUTES RECORD
======================
The following structures are defined in which to return the main attribute
set:
struct statx_timestamp {
__s64 tv_sec;
__s32 tv_nsec;
__s32 __reserved;
};
struct statx {
__u32 stx_mask;
__u32 stx_blksize;
__u64 stx_attributes;
__u32 stx_nlink;
__u32 stx_uid;
__u32 stx_gid;
__u16 stx_mode;
__u16 __spare0[1];
__u64 stx_ino;
__u64 stx_size;
__u64 stx_blocks;
__u64 __spare1[1];
struct statx_timestamp stx_atime;
struct statx_timestamp stx_btime;
struct statx_timestamp stx_ctime;
struct statx_timestamp stx_mtime;
__u32 stx_rdev_major;
__u32 stx_rdev_minor;
__u32 stx_dev_major;
__u32 stx_dev_minor;
__u64 __spare2[14];
};
The defined bits in request_mask and stx_mask are:
STATX_TYPE Want/got stx_mode & S_IFMT
STATX_MODE Want/got stx_mode & ~S_IFMT
STATX_NLINK Want/got stx_nlink
STATX_UID Want/got stx_uid
STATX_GID Want/got stx_gid
STATX_ATIME Want/got stx_atime{,_ns}
STATX_MTIME Want/got stx_mtime{,_ns}
STATX_CTIME Want/got stx_ctime{,_ns}
STATX_INO Want/got stx_ino
STATX_SIZE Want/got stx_size
STATX_BLOCKS Want/got stx_blocks
STATX_BASIC_STATS [The stuff in the normal stat struct]
STATX_BTIME Want/got stx_btime{,_ns}
STATX_ALL [All currently available stuff]
stx_btime is the file creation time, stx_mask is a bitmask indicating the
data provided and __spares*[] are where as-yet undefined fields can be
placed.
Time fields are structures with separate seconds and nanoseconds fields
plus a reserved field in case we want to add even finer resolution. Note
that times will be negative if before 1970; in such a case, the nanosecond
fields will also be negative if not zero.
The bits defined in the stx_attributes field convey information about a
file, how it is accessed, where it is and what it does. The following
attributes map to FS_*_FL flags and are the same numerical value:
STATX_ATTR_COMPRESSED File is compressed by the fs
STATX_ATTR_IMMUTABLE File is marked immutable
STATX_ATTR_APPEND File is append-only
STATX_ATTR_NODUMP File is not to be dumped
STATX_ATTR_ENCRYPTED File requires key to decrypt in fs
Within the kernel, the supported flags are listed by:
KSTAT_ATTR_FS_IOC_FLAGS
[Are any other IOC flags of sufficient general interest to be exposed
through this interface?]
New flags include:
STATX_ATTR_AUTOMOUNT Object is an automount trigger
These are for the use of GUI tools that might want to mark files specially,
depending on what they are.
Fields in struct statx come in a number of classes:
(0) stx_dev_*, stx_blksize.
These are local system information and are always available.
(1) stx_mode, stx_nlinks, stx_uid, stx_gid, stx_[amc]time, stx_ino,
stx_size, stx_blocks.
These will be returned whether the caller asks for them or not. The
corresponding bits in stx_mask will be set to indicate whether they
actually have valid values.
If the caller didn't ask for them, then they may be approximated. For
example, NFS won't waste any time updating them from the server,
unless as a byproduct of updating something requested.
If the values don't actually exist for the underlying object (such as
UID or GID on a DOS file), then the bit won't be set in the stx_mask,
even if the caller asked for the value. In such a case, the returned
value will be a fabrication.
Note that there are instances where the type might not be valid, for
instance Windows reparse points.
(2) stx_rdev_*.
This will be set only if stx_mode indicates we're looking at a
blockdev or a chardev, otherwise will be 0.
(3) stx_btime.
Similar to (1), except this will be set to 0 if it doesn't exist.
=======
TESTING
=======
The following test program can be used to test the statx system call:
samples/statx/test-statx.c
Just compile and run, passing it paths to the files you want to examine.
The file is built automatically if CONFIG_SAMPLES is enabled.
Here's some example output. Firstly, an NFS directory that crosses to
another FSID. Note that the AUTOMOUNT attribute is set because transiting
this directory will cause d_automount to be invoked by the VFS.
[root@andromeda ~]# /tmp/test-statx -A /warthog/data
statx(/warthog/data) = 0
results=7ff
Size: 4096 Blocks: 8 IO Block: 1048576 directory
Device: 00:26 Inode: 1703937 Links: 125
Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041
Access: 2016-11-24 09:02:12.219699527+0000
Modify: 2016-11-17 10:44:36.225653653+0000
Change: 2016-11-17 10:44:36.225653653+0000
Attributes: 0000000000001000 (-------- -------- -------- -------- -------- -------- ---m---- --------)
Secondly, the result of automounting on that directory.
[root@andromeda ~]# /tmp/test-statx /warthog/data
statx(/warthog/data) = 0
results=7ff
Size: 4096 Blocks: 8 IO Block: 1048576 directory
Device: 00:27 Inode: 2 Links: 125
Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041
Access: 2016-11-24 09:02:12.219699527+0000
Modify: 2016-11-17 10:44:36.225653653+0000
Change: 2016-11-17 10:44:36.225653653+0000
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Update code that relied on sched.h including various MM types for them.
This will allow us to remove the <linux/mm_types.h> include from <linux/sched.h>.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull cgroup updates from Tejun Heo:
"Several noteworthy changes.
- Parav's rdma controller is finally merged. It is very straight
forward and can limit the abosolute numbers of common rdma
constructs used by different cgroups.
- kernel/cgroup.c got too chubby and disorganized. Created
kernel/cgroup/ subdirectory and moved all cgroup related files
under kernel/ there and reorganized the core code. This hurts for
backporting patches but was long overdue.
- cgroup v2 process listing reimplemented so that it no longer
depends on allocating a buffer large enough to cache the entire
result to sort and uniq the output. v2 has always mangled the sort
order to ensure that users don't depend on the sorted output, so
this shouldn't surprise anybody. This makes the pid listing
functions use the same iterators that are used internally, which
have to have the same iterating capabilities anyway.
- perf cgroup filtering now works automatically on cgroup v2. This
patch was posted a long time ago but somehow fell through the
cracks.
- misc fixes asnd documentation updates"
* 'for-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (27 commits)
kernfs: fix locking around kernfs_ops->release() callback
cgroup: drop the matching uid requirement on migration for cgroup v2
cgroup, perf_event: make perf_event controller work on cgroup2 hierarchy
cgroup: misc cleanups
cgroup: call subsys->*attach() only for subsystems which are actually affected by migration
cgroup: track migration context in cgroup_mgctx
cgroup: cosmetic update to cgroup_taskset_add()
rdmacg: Fixed uninitialized current resource usage
cgroup: Add missing cgroup-v2 PID controller documentation.
rdmacg: Added documentation for rdmacg
IB/core: added support to use rdma cgroup controller
rdmacg: Added rdma cgroup controller
cgroup: fix a comment typo
cgroup: fix RCU related sparse warnings
cgroup: move namespace code to kernel/cgroup/namespace.c
cgroup: rename functions for consistency
cgroup: move v1 mount functions to kernel/cgroup/cgroup-v1.c
cgroup: separate out cgroup1_kf_syscall_ops
cgroup: refactor mount path and clearly distinguish v1 and v2 paths
cgroup: move cgroup v1 specific code to kernel/cgroup/cgroup-v1.c
...
->fault(), ->page_mkwrite(), and ->pfn_mkwrite() calls do not need to
take a vma and vmf parameter when the vma already resides in vmf.
Remove the vma parameter to simplify things.
[arnd@arndb.de: fix ARM build]
Link: http://lkml.kernel.org/r/20170125223558.1451224-1-arnd@arndb.de
Link: http://lkml.kernel.org/r/148521301778.19116.10840599906674778980.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jan Kara <jack@suse.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
