Pull vfs fixes from Al Viro:
"A couple of trivial patches that fell through the cracks last cycle"
* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fs: fix indentation in deactivate_super()
vfs: Remove duplicated d_mountpoint check in __is_local_mountpoint
Pull block updates from Jens Axboe:
"Core block changes that have been queued up for this release:
- Remove dead blk-throttle and blk-wbt code (Guoqing)
- Include pid in blktrace note traces (Jan)
- Don't spew I/O errors on wouldblock termination (me)
- Zone append addition (Johannes, Keith, Damien)
- IO accounting improvements (Konstantin, Christoph)
- blk-mq hardware map update improvements (Ming)
- Scheduler dispatch improvement (Salman)
- Inline block encryption support (Satya)
- Request map fixes and improvements (Weiping)
- blk-iocost tweaks (Tejun)
- Fix for timeout failing with error injection (Keith)
- Queue re-run fixes (Douglas)
- CPU hotplug improvements (Christoph)
- Queue entry/exit improvements (Christoph)
- Move DMA drain handling to the few drivers that use it (Christoph)
- Partition handling cleanups (Christoph)"
* tag 'for-5.8/block-2020-06-01' of git://git.kernel.dk/linux-block: (127 commits)
block: mark bio_wouldblock_error() bio with BIO_QUIET
blk-wbt: rename __wbt_update_limits to wbt_update_limits
blk-wbt: remove wbt_update_limits
blk-throttle: remove tg_drain_bios
blk-throttle: remove blk_throtl_drain
null_blk: force complete for timeout request
blk-mq: drain I/O when all CPUs in a hctx are offline
blk-mq: add blk_mq_all_tag_iter
blk-mq: open code __blk_mq_alloc_request in blk_mq_alloc_request_hctx
blk-mq: use BLK_MQ_NO_TAG in more places
blk-mq: rename BLK_MQ_TAG_FAIL to BLK_MQ_NO_TAG
blk-mq: move more request initialization to blk_mq_rq_ctx_init
blk-mq: simplify the blk_mq_get_request calling convention
blk-mq: remove the bio argument to ->prepare_request
nvme: force complete cancelled requests
blk-mq: blk-mq: provide forced completion method
block: fix a warning when blkdev.h is included for !CONFIG_BLOCK builds
block: blk-crypto-fallback: remove redundant initialization of variable err
block: reduce part_stat_lock() scope
block: use __this_cpu_add() instead of access by smp_processor_id()
...
The name is only printed for a not registered bdi in writeback. Use the
device name there as is more useful anyway for the unlike case that the
warning triggers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Commit 6fcf0c72e4, a fix to get_tree_bdev() put a missing blkdev_put() in
the wrong place, before a warnf() that displays the bdev under
consideration rather after it.
This results in a silent lockup in printk("%pg") called via warnf() from
get_tree_bdev() under some circumstances when there's a race with the
blockdev being frozen. This can be caused by xfstests/tests/generic/085 in
combination with Lukas Czerner's ext4 mount API conversion patchset. It
looks like it ought to occur with other users of get_tree_bdev() such as
XFS, but apparently doesn't.
Fix this by switching the order of the lines.
Fixes: 6fcf0c72e4 ("vfs: add missing blkdev_put() in get_tree_bdev()")
Reported-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Ian Kent <raven@themaw.net>
cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When a filesystem is unmounted, we currently call fsnotify_sb_delete()
before evict_inodes(), which means that fsnotify_unmount_inodes()
must iterate over all inodes on the superblock looking for any inodes
with watches. This is inefficient and can lead to livelocks as it
iterates over many unwatched inodes.
At this point, SB_ACTIVE is gone and dropping refcount to zero kicks
the inode out out immediately, so anything processed by
fsnotify_sb_delete / fsnotify_unmount_inodes gets evicted in that loop.
After that, the call to evict_inodes will evict everything else with a
zero refcount.
This should speed things up overall, and avoid livelocks in
fsnotify_unmount_inodes().
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull mount fixes from Al Viro:
"A couple of regressions from the mount series"
* 'work.mount3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
vfs: add missing blkdev_put() in get_tree_bdev()
shmem: fix LSM options parsing
Pull fuse updates from Miklos Szeredi:
- Continue separating the transport (user/kernel communication) and the
filesystem layers of fuse. Getting rid of most layering violations
will allow for easier cleanup and optimization later on.
- Prepare for the addition of the virtio-fs filesystem. The actual
filesystem will be introduced by a separate pull request.
- Convert to new mount API.
- Various fixes, optimizations and cleanups.
* tag 'fuse-update-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: (55 commits)
fuse: Make fuse_args_to_req static
fuse: fix memleak in cuse_channel_open
fuse: fix beyond-end-of-page access in fuse_parse_cache()
fuse: unexport fuse_put_request
fuse: kmemcg account fs data
fuse: on 64-bit store time in d_fsdata directly
fuse: fix missing unlock_page in fuse_writepage()
fuse: reserve byteswapped init opcodes
fuse: allow skipping control interface and forced unmount
fuse: dissociate DESTROY from fuseblk
fuse: delete dentry if timeout is zero
fuse: separate fuse device allocation and installation in fuse_conn
fuse: add fuse_iqueue_ops callbacks
fuse: extract fuse_fill_super_common()
fuse: export fuse_dequeue_forget() function
fuse: export fuse_get_unique()
fuse: export fuse_send_init_request()
fuse: export fuse_len_args()
fuse: export fuse_end_request()
fuse: fix request limit
...
Pull misc mount API conversions from Al Viro:
"Conversions to new API for shmem and friends and for mount_mtd()-using
filesystems.
As for the rest of the mount API conversions in -next, some of them
belong in the individual trees (e.g. binderfs one should definitely go
through android folks, after getting redone on top of their changes).
I'm going to drop those and send the rest (trivial ones + stuff ACKed
by maintainers) in a separate series - by that point they are
independent from each other.
Some stuff has already migrated into individual trees (NFS conversion,
for example, or FUSE stuff, etc.); those presumably will go through
the regular merges from corresponding trees."
* 'work.mount2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
vfs: Make fs_parse() handle fs_param_is_fd-type params better
vfs: Convert ramfs, shmem, tmpfs, devtmpfs, rootfs to use the new mount API
shmem_parse_one(): switch to use of fs_parse()
shmem_parse_options(): take handling a single option into a helper
shmem_parse_options(): don't bother with mpol in separate variable
shmem_parse_options(): use a separate structure to keep the results
make shmem_fill_super() static
make ramfs_fill_super() static
devtmpfs: don't mix {ramfs,shmem}_fill_super() with mount_single()
vfs: Convert squashfs to use the new mount API
mtd: Kill mount_mtd()
vfs: Convert jffs2 to use the new mount API
vfs: Convert cramfs to use the new mount API
vfs: Convert romfs to use the new mount API
vfs: Add a single-or-reconfig keying to vfs_get_super()
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
Pull fscrypt updates from Eric Biggers:
"This is a large update to fs/crypto/ which includes:
- Add ioctls that add/remove encryption keys to/from a
filesystem-level keyring.
These fix user-reported issues where e.g. an encrypted home
directory can break NetworkManager, sshd, Docker, etc. because they
don't get access to the needed keyring. These ioctls also provide a
way to lock encrypted directories that doesn't use the
vm.drop_caches sysctl, so is faster, more reliable, and doesn't
always need root.
- Add a new encryption policy version ("v2") which switches to a more
standard, secure, and flexible key derivation function, and starts
verifying that the correct key was supplied before using it.
The key derivation improvement is needed for its own sake as well
as for ongoing feature work for which the current way is too
inflexible.
Work is in progress to update both Android and the 'fscrypt' userspace
tool to use both these features. (Working patches are available and
just need to be reviewed+merged.) Chrome OS will likely use them too.
This has also been tested on ext4, f2fs, and ubifs with xfstests --
both the existing encryption tests, and the new tests for this. This
has also been in linux-next since Aug 16 with no reported issues. I'm
also using an fscrypt v2-encrypted home directory on my personal
desktop"
* tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscrypt: (27 commits)
ext4 crypto: fix to check feature status before get policy
fscrypt: document the new ioctls and policy version
ubifs: wire up new fscrypt ioctls
f2fs: wire up new fscrypt ioctls
ext4: wire up new fscrypt ioctls
fscrypt: require that key be added when setting a v2 encryption policy
fscrypt: add FS_IOC_REMOVE_ENCRYPTION_KEY_ALL_USERS ioctl
fscrypt: allow unprivileged users to add/remove keys for v2 policies
fscrypt: v2 encryption policy support
fscrypt: add an HKDF-SHA512 implementation
fscrypt: add FS_IOC_GET_ENCRYPTION_KEY_STATUS ioctl
fscrypt: add FS_IOC_REMOVE_ENCRYPTION_KEY ioctl
fscrypt: add FS_IOC_ADD_ENCRYPTION_KEY ioctl
fscrypt: rename keyinfo.c to keysetup.c
fscrypt: move v1 policy key setup to keysetup_v1.c
fscrypt: refactor key setup code in preparation for v2 policies
fscrypt: rename fscrypt_master_key to fscrypt_direct_key
fscrypt: add ->ci_inode to fscrypt_info
fscrypt: use FSCRYPT_* definitions, not FS_*
fscrypt: use FSCRYPT_ prefix for uapi constants
...
The unused vfs code can be removed. Don't pass empty subtype (same as if
->parse callback isn't called).
The bits that are left involve determining whether it's permitted to split the
filesystem type string passed in to mount(2). Consequently, this means that we
cannot get rid of the FS_HAS_SUBTYPE flag unless we define that a type string
with a dot in it always indicates a subtype specification.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Add an additional keying mode to vfs_get_super() to indicate that only a
single superblock should exist in the system, and that, if it does, further
mounts should invoke reconfiguration upon it.
This allows mount_single() to be replaced.
[Fix by Eric Biggers folded in]
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Create a function, get_tree_bdev(), that is fs_context-aware and a
->get_tree() counterpart of mount_bdev().
It caches the block device pointer in the fs_context struct so that this
information can be passed into sget_fc()'s test and set functions.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jens Axboe <axboe@kernel.dk>
cc: linux-block@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Add fields to the superblock to track the min and max
timestamps supported by filesystems.
Initially, when a superblock is allocated, initialize
it to the max and min values the fields can hold.
Individual filesystems override these to match their
actual limits.
Pseudo filesystems are assumed to always support the
min and max allowable values for the fields.
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Acked-by: Jeff Layton <jlayton@kernel.org>
Add a new fscrypt ioctl, FS_IOC_ADD_ENCRYPTION_KEY. This ioctl adds an
encryption key to the filesystem's fscrypt keyring ->s_master_keys,
making any files encrypted with that key appear "unlocked".
Why we need this
~~~~~~~~~~~~~~~~
The main problem is that the "locked/unlocked" (ciphertext/plaintext)
status of encrypted files is global, but the fscrypt keys are not.
fscrypt only looks for keys in the keyring(s) the process accessing the
filesystem is subscribed to: the thread keyring, process keyring, and
session keyring, where the session keyring may contain the user keyring.
Therefore, userspace has to put fscrypt keys in the keyrings for
individual users or sessions. But this means that when a process with a
different keyring tries to access encrypted files, whether they appear
"unlocked" or not is nondeterministic. This is because it depends on
whether the files are currently present in the inode cache.
Fixing this by consistently providing each process its own view of the
filesystem depending on whether it has the key or not isn't feasible due
to how the VFS caches work. Furthermore, while sometimes users expect
this behavior, it is misguided for two reasons. First, it would be an
OS-level access control mechanism largely redundant with existing access
control mechanisms such as UNIX file permissions, ACLs, LSMs, etc.
Encryption is actually for protecting the data at rest.
Second, almost all users of fscrypt actually do need the keys to be
global. The largest users of fscrypt, Android and Chromium OS, achieve
this by having PID 1 create a "session keyring" that is inherited by
every process. This works, but it isn't scalable because it prevents
session keyrings from being used for any other purpose.
On general-purpose Linux distros, the 'fscrypt' userspace tool [1] can't
similarly abuse the session keyring, so to make 'sudo' work on all
systems it has to link all the user keyrings into root's user keyring
[2]. This is ugly and raises security concerns. Moreover it can't make
the keys available to system services, such as sshd trying to access the
user's '~/.ssh' directory (see [3], [4]) or NetworkManager trying to
read certificates from the user's home directory (see [5]); or to Docker
containers (see [6], [7]).
By having an API to add a key to the *filesystem* we'll be able to fix
the above bugs, remove userspace workarounds, and clearly express the
intended semantics: the locked/unlocked status of an encrypted directory
is global, and encryption is orthogonal to OS-level access control.
Why not use the add_key() syscall
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
We use an ioctl for this API rather than the existing add_key() system
call because the ioctl gives us the flexibility needed to implement
fscrypt-specific semantics that will be introduced in later patches:
- Supporting key removal with the semantics such that the secret is
removed immediately and any unused inodes using the key are evicted;
also, the eviction of any in-use inodes can be retried.
- Calculating a key-dependent cryptographic identifier and returning it
to userspace.
- Allowing keys to be added and removed by non-root users, but only keys
for v2 encryption policies; and to prevent denial-of-service attacks,
users can only remove keys they themselves have added, and a key is
only really removed after all users who added it have removed it.
Trying to shoehorn these semantics into the keyrings syscalls would be
very difficult, whereas the ioctls make things much easier.
However, to reuse code the implementation still uses the keyrings
service internally. Thus we get lockless RCU-mode key lookups without
having to re-implement it, and the keys automatically show up in
/proc/keys for debugging purposes.
References:
[1] https://github.com/google/fscrypt
[2] https://goo.gl/55cCrI#heading=h.vf09isp98isb
[3] https://github.com/google/fscrypt/issues/111#issuecomment-444347939
[4] https://github.com/google/fscrypt/issues/116
[5] https://bugs.launchpad.net/ubuntu/+source/fscrypt/+bug/1770715
[6] https://github.com/google/fscrypt/issues/128
[7] https://askubuntu.com/questions/1130306/cannot-run-docker-on-an-encrypted-filesystem
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Biggers <ebiggers@google.com>
In "consolidate the capability checks in sget_{fc,userns}())" the
wrong argument had been passed to mount_capable() by sget_fc().
That mistake had been further obscured later, when switching
mount_capable() to fs_context has moved the calculation of
bogus argument from sget_fc() to mount_capable() itself. It
should've been fc->user_ns all along.
Screwed-up-by: Al Viro <viro@zeniv.linux.org.uk>
Reported-by: Christian Brauner <christian@brauner.io>
Tested-by: Christian Brauner <christian@brauner.io>
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Provide a field in the fs_context struct through which bits in the
sb->s_iflags superblock field can be set.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-fsdevel@vger.kernel.org
Call graph of vfs_get_tree():
vfs_fsconfig_locked() # neither kernmount, nor submount
do_new_mount() # neither kernmount, nor submount
fc_mount()
afs_mntpt_do_automount() # submount
mount_one_hugetlbfs() # kernmount
pid_ns_prepare_proc() # kernmount
mq_create_mount() # kernmount
vfs_kern_mount()
simple_pin_fs() # kernmount
vfs_submount() # submount
kern_mount() # kernmount
init_mount_tree()
btrfs_mount()
nfs_do_root_mount()
The first two need the check (unconditionally).
init_mount_tree() is setting rootfs up; any capability
checks make zero sense for that one. And btrfs_mount()/
nfs_do_root_mount() have the checks already done in their
callers.
IOW, we can shift mount_capable() handling into
the two callers - one in the normal case of mount(2),
another - in fsconfig(2) handling of FSCONFIG_CMD_CREATE.
I.e. the syscalls that set a new filesystem up.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
