linux.git/fs/super.c, branch v6.0

Merge tag 'fuse-update-6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse

2022-08-08T18:10:02+00:00

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()

vfs: function to prevent re-use of block-device-based superblocks

2022-07-27T09:30:30+00:00

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 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Miklos Szeredi

mm: shrinkers: provide shrinkers with names

2022-07-04T01:08:40+00:00

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:
    -[:]-
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 
Link: https://lkml.kernel.org/r/20220601032227.4076670-4-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin 
Cc: Christophe JAILLET 
Cc: Dave Chinner 
Cc: Hillf Danton 
Cc: Kent Overstreet 
Cc: Muchun Song 
Signed-off-by: Andrew Morton

block: add a bdev_stable_writes helper

2022-04-18T01:49:59+00:00

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 
Reviewed-by: Martin K. Petersen 
Reviewed-by: Chaitanya Kulkarni 
Link: https://lore.kernel.org/r/20220415045258.199825-15-hch@lst.de
Signed-off-by: Jens Axboe

vfs: make freeze_super abort when sync_filesystem returns error

2022-01-30T16:59:47+00:00

If we fail to synchronize the filesystem while preparing to freeze the
fs, abort the freeze.

Signed-off-by: Darrick J. Wong 
Reviewed-by: Jan Kara 
Reviewed-by: Christoph Hellwig 
Acked-by: Christian Brauner

mm: remove cleancache

2022-01-22T06:33:38+00:00

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 814bbf49dcd0 ("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 
Reviewed-by: Juergen Gross 
Acked-by: Geert Uytterhoeven 
Cc: Konrad Rzeszutek Wilk 
Cc: Hugh Dickins 
Cc: Seth Jennings 
Cc: Dan Streetman 
Cc: Vitaly Wool 
Cc: Matthew Wilcox (Oracle) 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

devtmpfs regression fix: reconfigure on each mount

2022-01-17T07:40:29+00:00

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: d401727ea0d7 ("devtmpfs: don't mix {ramfs,shmem}_fill_super() with mount_single()")
Acked-by: Christian Brauner 
Cc: Al Viro 
Signed-off-by: NeilBrown 
Signed-off-by: Linus Torvalds

fs: explicitly unregister per-superblock BDIs

2021-11-06T20:30:34+00:00

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 
Reviewed-by: Jan Kara 
Cc: Miquel Raynal 
Cc: Richard Weinberger 
Cc: Vignesh Raghavendra 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

block: remove the bd_bdi in struct block_device

2021-08-09T17:53:26+00:00

Just retrieve the bdi from the disk.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Jan Kara 
Reviewed-by: Johannes Thumshirn 
Link: https://lore.kernel.org/r/20210809141744.1203023-6-hch@lst.de
Signed-off-by: Jens Axboe

block: move bd_mutex to struct gendisk

2021-06-01T13:44:32+00:00

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 
Reviewed-by: Ming Lei 
Acked-by: Roger Pau Monné 
Link: https://lore.kernel.org/r/20210525061301.2242282-4-hch@lst.de
Signed-off-by: Jens Axboe