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Linus Torvalds bd90741318 misc pile
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Merge tag 'pull-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull misc vfs updates from Al Viro:
 "misc pile"

* tag 'pull-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs: sysv: Fix sysv_nblocks() returns wrong value
  get rid of INT_LIMIT, use type_max() instead
  btrfs: replace INT_LIMIT(loff_t) with OFFSET_MAX
  fs: simplify vfs_get_super
  fs: drop useless condition from inode_needs_update_time
2022-12-12 18:38:47 -08:00
Christoph Hellwig cda2ed05aa fs: simplify vfs_get_super
Remove the pointless keying argument and associated enum and pass the
fill_super callback and a "bool reconf" instead.  Also mark the function
static given that there are no users outside of super.c.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-11-25 00:52:19 -05:00
Eric Biggers ccd30a476f fscrypt: fix keyring memory leak on mount failure
Commit d7e7b9af10 ("fscrypt: stop using keyrings subsystem for
fscrypt_master_key") moved the keyring destruction from __put_super() to
generic_shutdown_super() so that the filesystem's block device(s) are
still available.  Unfortunately, this causes a memory leak in the case
where a mount is attempted with the test_dummy_encryption mount option,
but the mount fails after the option has already been processed.

To fix this, attempt the keyring destruction in both places.

Reported-by: syzbot+104c2a89561289cec13e@syzkaller.appspotmail.com
Fixes: d7e7b9af10 ("fscrypt: stop using keyrings subsystem for fscrypt_master_key")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Link: https://lore.kernel.org/r/20221011213838.209879-1-ebiggers@kernel.org
2022-10-19 20:54:43 -07:00
Eric Biggers d7e7b9af10 fscrypt: stop using keyrings subsystem for fscrypt_master_key
The approach of fs/crypto/ internally managing the fscrypt_master_key
structs as the payloads of "struct key" objects contained in a
"struct key" keyring has outlived its usefulness.  The original idea was
to simplify the code by reusing code from the keyrings subsystem.
However, several issues have arisen that can't easily be resolved:

- When a master key struct is destroyed, blk_crypto_evict_key() must be
  called on any per-mode keys embedded in it.  (This started being the
  case when inline encryption support was added.)  Yet, the keyrings
  subsystem can arbitrarily delay the destruction of keys, even past the
  time the filesystem was unmounted.  Therefore, currently there is no
  easy way to call blk_crypto_evict_key() when a master key is
  destroyed.  Currently, this is worked around by holding an extra
  reference to the filesystem's request_queue(s).  But it was overlooked
  that the request_queue reference is *not* guaranteed to pin the
  corresponding blk_crypto_profile too; for device-mapper devices that
  support inline crypto, it doesn't.  This can cause a use-after-free.

- When the last inode that was using an incompletely-removed master key
  is evicted, the master key removal is completed by removing the key
  struct from the keyring.  Currently this is done via key_invalidate().
  Yet, key_invalidate() takes the key semaphore.  This can deadlock when
  called from the shrinker, since in fscrypt_ioctl_add_key(), memory is
  allocated with GFP_KERNEL under the same semaphore.

- More generally, the fact that the keyrings subsystem can arbitrarily
  delay the destruction of keys (via garbage collection delay, or via
  random processes getting temporary key references) is undesirable, as
  it means we can't strictly guarantee that all secrets are ever wiped.

- Doing the master key lookups via the keyrings subsystem results in the
  key_permission LSM hook being called.  fscrypt doesn't want this, as
  all access control for encrypted files is designed to happen via the
  files themselves, like any other files.  The workaround which SELinux
  users are using is to change their SELinux policy to grant key search
  access to all domains.  This works, but it is an odd extra step that
  shouldn't really have to be done.

The fix for all these issues is to change the implementation to what I
should have done originally: don't use the keyrings subsystem to keep
track of the filesystem's fscrypt_master_key structs.  Instead, just
store them in a regular kernel data structure, and rework the reference
counting, locking, and lifetime accordingly.  Retain support for
RCU-mode key lookups by using a hash table.  Replace fscrypt_sb_free()
with fscrypt_sb_delete(), which releases the keys synchronously and runs
a bit earlier during unmount, so that block devices are still available.

A side effect of this patch is that neither the master keys themselves
nor the filesystem keyrings will be listed in /proc/keys anymore.
("Master key users" and the master key users keyrings will still be
listed.)  However, this was mostly an implementation detail, and it was
intended just for debugging purposes.  I don't know of anyone using it.

This patch does *not* change how "master key users" (->mk_users) works;
that still uses the keyrings subsystem.  That is still needed for key
quotas, and changing that isn't necessary to solve the issues listed
above.  If we decide to change that too, it would be a separate patch.

I've marked this as fixing the original commit that added the fscrypt
keyring, but as noted above the most important issue that this patch
fixes wasn't introduced until the addition of inline encryption support.

Fixes: 22d94f493b ("fscrypt: add FS_IOC_ADD_ENCRYPTION_KEY ioctl")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20220901193208.138056-2-ebiggers@kernel.org
2022-09-21 20:33:06 -07:00
Linus Torvalds 2bd5d41e0e fuse update for 6.0
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Merge tag 'fuse-update-6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse

Pull fuse updates from Miklos Szeredi:

 - Fix an issue with reusing the bdi in case of block based filesystems

 - Allow root (in init namespace) to access fuse filesystems in user
   namespaces if expicitly enabled with a module param

 - Misc fixes

* tag 'fuse-update-6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: retire block-device-based superblock on force unmount
  vfs: function to prevent re-use of block-device-based superblocks
  virtio_fs: Modify format for virtio_fs_direct_access
  virtiofs: delete unused parameter for virtio_fs_cleanup_vqs
  fuse: Add module param for CAP_SYS_ADMIN access bypassing allow_other
  fuse: Remove the control interface for virtio-fs
  fuse: ioctl: translate ENOSYS
  fuse: limit nsec
  fuse: avoid unnecessary spinlock bump
  fuse: fix deadlock between atomic O_TRUNC and page invalidation
  fuse: write inode in fuse_release()
2022-08-08 11:10:02 -07:00
Daniil Lunev 04b9407197 vfs: function to prevent re-use of block-device-based superblocks
The function is to be called from filesystem-specific code to mark a
superblock to be ignored by superblock test and thus never re-used.  The
function also unregisters bdi if the bdi is per-superblock to avoid
collision if a new superblock is created to represent the filesystem.
generic_shutdown_super() skips unregistering bdi for a retired superlock as
it assumes retire function has already done it.

This patch adds the functionality only for the block-device-based supers,
since the primary use case of the feature is to gracefully handle force
unmount of external devices, mounted with FUSE.  This can be further
extended to cover all superblocks, if the need arises.

Signed-off-by: Daniil Lunev <dlunev@chromium.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2022-07-27 11:30:30 +02:00
Roman Gushchin e33c267ab7 mm: shrinkers: provide shrinkers with names
Currently shrinkers are anonymous objects.  For debugging purposes they
can be identified by count/scan function names, but it's not always
useful: e.g.  for superblock's shrinkers it's nice to have at least an
idea of to which superblock the shrinker belongs.

This commit adds names to shrinkers.  register_shrinker() and
prealloc_shrinker() functions are extended to take a format and arguments
to master a name.

In some cases it's not possible to determine a good name at the time when
a shrinker is allocated.  For such cases shrinker_debugfs_rename() is
provided.

The expected format is:
    <subsystem>-<shrinker_type>[:<instance>]-<id>
For some shrinkers an instance can be encoded as (MAJOR:MINOR) pair.

After this change the shrinker debugfs directory looks like:
  $ cd /sys/kernel/debug/shrinker/
  $ ls
    dquota-cache-16     sb-devpts-28     sb-proc-47       sb-tmpfs-42
    mm-shadow-18        sb-devtmpfs-5    sb-proc-48       sb-tmpfs-43
    mm-zspool:zram0-34  sb-hugetlbfs-17  sb-pstore-31     sb-tmpfs-44
    rcu-kfree-0         sb-hugetlbfs-33  sb-rootfs-2      sb-tmpfs-49
    sb-aio-20           sb-iomem-12      sb-securityfs-6  sb-tracefs-13
    sb-anon_inodefs-15  sb-mqueue-21     sb-selinuxfs-22  sb-xfs:vda1-36
    sb-bdev-3           sb-nsfs-4        sb-sockfs-8      sb-zsmalloc-19
    sb-bpf-32           sb-pipefs-14     sb-sysfs-26      thp-deferred_split-10
    sb-btrfs:vda2-24    sb-proc-25       sb-tmpfs-1       thp-zero-9
    sb-cgroup2-30       sb-proc-39       sb-tmpfs-27      xfs-buf:vda1-37
    sb-configfs-23      sb-proc-41       sb-tmpfs-29      xfs-inodegc:vda1-38
    sb-dax-11           sb-proc-45       sb-tmpfs-35
    sb-debugfs-7        sb-proc-46       sb-tmpfs-40

[roman.gushchin@linux.dev: fix build warnings]
  Link: https://lkml.kernel.org/r/Yr+ZTnLb9lJk6fJO@castle
  Reported-by: kernel test robot <lkp@intel.com>
Link: https://lkml.kernel.org/r/20220601032227.4076670-4-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-03 18:08:40 -07:00
Christoph Hellwig 36d254893a block: add a bdev_stable_writes helper
Add a helper to check the stable writes flag based on the block_device
instead of having to poke into the block layer internal request_queue.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220415045258.199825-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-04-17 19:49:59 -06:00
Darrick J. Wong 2719c7160d vfs: make freeze_super abort when sync_filesystem returns error
If we fail to synchronize the filesystem while preparing to freeze the
fs, abort the freeze.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Christian Brauner <brauner@kernel.org>
2022-01-30 08:59:47 -08:00
Christoph Hellwig 0a4ee51818 mm: remove cleancache
Patch series "remove Xen tmem leftovers".

Since the removal of the Xen tmem driver in 2019, the cleancache hooks
are entirely unused, as are large parts of frontswap.  This series
against linux-next (with the folio changes included) removes
cleancaches, and cuts down frontswap to the bits actually used by zswap.

This patch (of 13):

The cleancache subsystem is unused since the removal of Xen tmem driver
in commit 814bbf49dc ("xen: remove tmem driver").

[akpm@linux-foundation.org: remove now-unreachable code]

Link: https://lkml.kernel.org/r/20211224062246.1258487-1-hch@lst.de
Link: https://lkml.kernel.org/r/20211224062246.1258487-2-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Juergen Gross <jgross@suse.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
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>
2022-01-22 08:33:38 +02:00
NeilBrown a6097180d8 devtmpfs regression fix: reconfigure on each mount
Prior to Linux v5.4 devtmpfs used mount_single() which treats the given
mount options as "remount" options, so it updates the configuration of
the single super_block on each mount.

Since that was changed, the mount options used for devtmpfs are ignored.
This is a regression which affect systemd - which mounts devtmpfs with
"-o mode=755,size=4m,nr_inodes=1m".

This patch restores the "remount" effect by calling reconfigure_single()

Fixes: d401727ea0 ("devtmpfs: don't mix {ramfs,shmem}_fill_super() with mount_single()")
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-17 09:40:29 +02:00
Christoph Hellwig 0b3ea0926a fs: explicitly unregister per-superblock BDIs
Add a new SB_I_ flag to mark superblocks that have an ephemeral bdi
associated with them, and unregister it when the superblock is shut
down.

Link: https://lkml.kernel.org/r/20211021124441.668816-4-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:34 -07:00
Christoph Hellwig a11d7fc2d0 block: remove the bd_bdi in struct block_device
Just retrieve the bdi from the disk.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210809141744.1203023-6-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-09 11:53:26 -06:00
Christoph Hellwig a8698707a1 block: move bd_mutex to struct gendisk
Replace the per-block device bd_mutex with a per-gendisk open_mutex,
thus simplifying locking wherever we deal with partitions.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Link: https://lore.kernel.org/r/20210525061301.2242282-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-01 07:44:32 -06:00
Mickaël Salaün 83e804f0bf fs,security: Add sb_delete hook
The sb_delete security hook is called when shutting down a superblock,
which may be useful to release kernel objects tied to the superblock's
lifetime (e.g. inodes).

This new hook is needed by Landlock to release (ephemerally) tagged
struct inodes.  This comes from the unprivileged nature of Landlock
described in the next commit.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com>
Reviewed-by: Jann Horn <jannh@google.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210422154123.13086-7-mic@digikod.net
Signed-off-by: James Morris <jamorris@linux.microsoft.com>
2021-04-22 12:22:11 -07:00
Linus Torvalds 0e63a5c6ba It has been a relatively quiet cycle in docsland.
- As promised, the minimum Sphinx version to build the docs is now 1.7,
    and we have dropped support for Python 2 entirely.  That allowed the
    removal of a bunch of compatibility code.
 
  - A set of treewide warning fixups from Mauro that I applied after it
    became clear nobody else was going to deal with them.
 
  - The automarkup mechanism can now create cross-references from relative
    paths to RST files.
 
  - More translations, typo fixes, and warning fixes.
 
 No conflicts with any other tree as far as I know.
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Merge tag 'docs-5.12' of git://git.lwn.net/linux

Pull documentation updates from Jonathan Corbet:
 "It has been a relatively quiet cycle in docsland.

   - As promised, the minimum Sphinx version to build the docs is now
     1.7, and we have dropped support for Python 2 entirely. That
     allowed the removal of a bunch of compatibility code.

   - A set of treewide warning fixups from Mauro that I applied after it
     became clear nobody else was going to deal with them.

   - The automarkup mechanism can now create cross-references from
     relative paths to RST files.

   - More translations, typo fixes, and warning fixes"

* tag 'docs-5.12' of git://git.lwn.net/linux: (75 commits)
  docs: kernel-hacking: be more civil
  docs: Remove the Microsoft rhetoric
  Documentation/admin-guide: kernel-parameters: Update nohlt section
  doc/admin-guide: fix spelling mistake: "perfomance" -> "performance"
  docs: Document cross-referencing using relative path
  docs: Enable usage of relative paths to docs on automarkup
  docs: thermal: fix spelling mistakes
  Documentation: admin-guide: Update kvm/xen config option
  docs: Make syscalls' helpers naming consistent
  coding-style.rst: Avoid comma statements
  Documentation: /proc/loadavg: add 3 more field descriptions
  Documentation/submitting-patches: Add blurb about backtraces in commit messages
  Docs: drop Python 2 support
  Move our minimum Sphinx version to 1.7
  Documentation: input: define ABS_PRESSURE/ABS_MT_PRESSURE resolution as grams
  scripts/kernel-doc: add internal hyperlink to DOC: sections
  Update Documentation/admin-guide/sysctl/fs.rst
  docs: Update DTB format references
  docs: zh_CN: add iio index.rst translation
  docs/zh_CN: add iio ep93xx_adc.rst translation
  ...
2021-02-22 10:57:46 -08:00
Christoph Hellwig 6f0d9689b6 block: remove the NULL bdev check in bdev_read_only
Only a single caller can end up in bdev_read_only, so move the check
there.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-01-24 18:15:57 -07:00
Mauro Carvalho Chehab 961f3c898e fs: fix kernel-doc markups
Two markups are at the wrong place. Kernel-doc only
support having the comment just before the identifier.

Also, some identifiers have different names between their
prototypes and the kernel-doc markup.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/96b1e1b388600ab092331f6c4e88ff8e8779ce6c.1610610937.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-01-21 14:06:00 -07:00
Christoph Hellwig 4e7b5671c6 block: remove i_bdev
Switch the block device lookup interfaces to directly work with a dev_t
so that struct block_device references are only acquired by the
blkdev_get variants (and the blk-cgroup special case).  This means that
we now don't need an extra reference in the inode and can generally
simplify handling of struct block_device to keep the lookups contained
in the core block layer code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Coly Li <colyli@suse.de>		[bcache]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01 14:53:39 -07:00
Christoph Hellwig 60b498852b fs: remove get_super_thawed and get_super_exclusive_thawed
Just open code the wait in the only caller of both functions.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01 14:53:38 -07:00
Darrick J. Wong 9b8523423b vfs: move __sb_{start,end}_write* to fs.h
Now that we've straightened out the callers, move these three functions
to fs.h since they're fairly trivial.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
2020-11-10 16:53:11 -08:00
Darrick J. Wong 8a3c84b649 vfs: separate __sb_start_write into blocking and non-blocking helpers
Break this function into two helpers so that it's obvious that the
trylock versions return a value that must be checked, and the blocking
versions don't require that.  While we're at it, clean up the return
type mismatch.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2020-11-10 16:53:07 -08:00
Darrick J. Wong 22843291ef vfs: remove lockdep bogosity in __sb_start_write
__sb_start_write has some weird looking lockdep code that claims to
exist to handle nested freeze locking requests from xfs.  The code as
written seems broken -- if we think we hold a read lock on any of the
higher freeze levels (e.g. we hold SB_FREEZE_WRITE and are trying to
lock SB_FREEZE_PAGEFAULT), it converts a blocking lock attempt into a
trylock.

However, it's not correct to downgrade a blocking lock attempt to a
trylock unless the downgrading code or the callers are prepared to deal
with that situation.  Neither __sb_start_write nor its callers handle
this at all.  For example:

sb_start_pagefault ignores the return value completely, with the result
that if xfs_filemap_fault loses a race with a different thread trying to
fsfreeze, it will proceed without pagefault freeze protection (thereby
breaking locking rules) and then unlocks the pagefault freeze lock that
it doesn't own on its way out (thereby corrupting the lock state), which
leads to a system hang shortly afterwards.

Normally, this won't happen because our ownership of a read lock on a
higher freeze protection level blocks fsfreeze from grabbing a write
lock on that higher level.  *However*, if lockdep is offline,
lock_is_held_type unconditionally returns 1, which means that
percpu_rwsem_is_held returns 1, which means that __sb_start_write
unconditionally converts blocking freeze lock attempts into trylocks,
even when we *don't* hold anything that would block a fsfreeze.

Apparently this all held together until 5.10-rc1, when bugs in lockdep
caused lockdep to shut itself off early in an fstests run, and once
fstests gets to the "race writes with freezer" tests, kaboom.  This
might explain the long trail of vanishingly infrequent livelocks in
fstests after lockdep goes offline that I've never been able to
diagnose.

We could fix it by spinning on the trylock if wait==true, but AFAICT the
locking works fine if lockdep is not built at all (and I didn't see any
complaints running fstests overnight), so remove this snippet entirely.

NOTE: Commit f4b554af99 in 2015 created the current weird logic (which
used to exist in a different form in commit 5accdf82ba from 2012) in
__sb_start_write.  XFS solved this whole problem in the late 2.6 era by
creating a variant of transactions (XFS_TRANS_NO_WRITECOUNT) that don't
grab intwrite freeze protection, thus making lockdep's solution
unnecessary.  The commit claims that Dave Chinner explained that the
trylock hack + comment could be removed, but nobody ever did.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
2020-11-10 16:49:29 -08:00
Christoph Hellwig 1cb039f3dc bdi: replace BDI_CAP_STABLE_WRITES with a queue and a sb flag
The BDI_CAP_STABLE_WRITES is one of the few bits of information in the
backing_dev_info shared between the block drivers and the writeback code.
To help untangling the dependency replace it with a queue flag and a
superblock flag derived from it.  This also helps with the case of e.g.
a file system requiring stable writes due to its own checksumming, but
not forcing it on other users of the block device like the swap code.

One downside is that we an't support the stable_pages_required bdi
attribute in sysfs anymore.  It is replaced with a queue attribute which
also is writable for easier testing.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-24 13:43:39 -06:00
Linus Torvalds 4dbb29fe9d Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
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
2020-06-10 16:09:11 -07:00
Linus Torvalds 750a02ab8d for-5.8/block-2020-06-01
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Merge tag 'for-5.8/block-2020-06-01' of git://git.kernel.dk/linux-block

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()
  ...
2020-06-02 15:29:19 -07:00
Yufen Yu cc23402c1c fs: fix indentation in deactivate_super()
Fix the breaked indent in deactive_super().

Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-05-29 10:35:25 -04:00
Christoph Hellwig 1cd925d583 bdi: remove the name field in struct backing_dev_info
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>
2020-05-09 16:15:13 -06:00
Christoph Hellwig aef33c2ff8 bdi: simplify bdi_alloc
Merge the _node vs normal version and drop the superflous gfp_t argument.

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>
2020-05-09 16:15:13 -06:00
David Howells dd7bc8158b Fix use after free in get_tree_bdev()
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>
2020-04-28 14:37:40 -07:00
Eric Sandeen 1edc8eb2e9 fs: call fsnotify_sb_delete after evict_inodes
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>
2019-12-18 00:03:01 -05:00
Linus Torvalds 015c21ba59 Merge branch 'work.mount3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
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
2019-10-10 08:16:44 -07:00
Ian Kent 6fcf0c72e4 vfs: add missing blkdev_put() in get_tree_bdev()
Is there are a couple of missing blkdev_put() in get_tree_bdev()?

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-10-09 22:53:57 -04:00
Linus Torvalds 7b1373dd6e fuse update for 5.4
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Merge tag 'fuse-update-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse

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
  ...
2019-09-25 09:55:59 -07:00
Linus Torvalds bc7d9aee3f Merge branch 'work.mount2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
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()
2019-09-19 10:06:57 -07:00
Linus Torvalds cfb82e1df8 y2038: 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.
 
 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
2019-09-19 09:42:37 -07:00
Linus Torvalds 734d1ed83e fscrypt update for 5.4
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.
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Merge tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscrypt

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
  ...
2019-09-18 16:08:52 -07:00
David Howells c7eb686963 vfs: subtype handling moved to fuse
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>
2019-09-06 21:28:49 +02:00
David Howells 43ce4c1fea vfs: Add a single-or-reconfig keying to vfs_get_super()
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>
2019-09-05 14:34:23 -04:00
David Howells fe62c3a4e1 vfs: Create fs_context-aware mount_bdev() replacement
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>
2019-09-05 14:34:22 -04:00
Al Viro 533770cc0a new helper: get_tree_keyed()
For vfs_get_keyed_super users.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-09-05 14:34:22 -04:00
Deepa Dinamani 188d20bcd1 vfs: Add file timestamp range support
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>
2019-08-30 07:27:17 -07:00
Eric Biggers 22d94f493b fscrypt: add FS_IOC_ADD_ENCRYPTION_KEY ioctl
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>
2019-08-12 19:06:13 -07:00
Al Viro c2c44ec20a Unbreak mount_capable()
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>
2019-07-31 12:22:32 -04:00
Al Viro c23a0bbab3 convenience helper: get_tree_single()
counterpart of mount_single(); switch fusectl to it

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-07-04 22:01:58 -04:00
Al Viro 2ac295d4f0 convenience helper get_tree_nodev()
counterpart of mount_nodev().  Switch hugetlb and pseudo to it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-07-04 22:01:58 -04:00
David Howells 023d066a0d vfs: Kill sget_userns()
Kill sget_userns(), folding it into sget() as that's the only remaining
user.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-fsdevel@vger.kernel.org
2019-05-25 18:06:17 -04:00
David Howells c80fa7c830 vfs: Provide sb->s_iflags settings in fs_context struct
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
2019-05-25 18:00:03 -04:00
Al Viro c3aabf0780 move mount_capable() further out
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>
2019-05-25 18:00:02 -04:00
Al Viro 059338aae3 move mount_capable() calls to vfs_get_tree()
sget_fc() is called only from ->get_tree() instances and
the only instance not calling it is legacy_get_tree(),
which calls mount_capable() directly.

In all sget_fc() callers the checks could be moved to the
very beginning of ->get_tree() - ->user_ns is not changed
in between.  So lifting the checks to the only caller of
->get_tree() is OK.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-05-25 18:00:01 -04:00