Commit Graph

1297 Commits

Author SHA1 Message Date
Miklos Szeredi
e1e71c1688 fuse: fix use after free in fuse_read_interrupt()
There is a potential race between fuse_read_interrupt() and
fuse_request_end().

TASK1
  in fuse_read_interrupt(): delete req->intr_entry (while holding
  fiq->lock)

TASK2
  in fuse_request_end(): req->intr_entry is empty -> skip fiq->lock
  wake up TASK3

TASK3
  request is freed

TASK1
  in fuse_read_interrupt(): dereference req->in.h.unique ***BAM***


Fix by always grabbing fiq->lock if the request was ever interrupted
(FR_INTERRUPTED set) thereby serializing with concurrent
fuse_read_interrupt() calls.

FR_INTERRUPTED is set before the request is queued on fiq->interrupts.
Dequeing the request is done with list_del_init() but FR_INTERRUPTED is not
cleared in this case.

Reported-by: lijiazi <lijiazi@xiaomi.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-08-04 13:22:58 +02:00
Jan Kara
8bcbbe9c7c fuse: Convert to using invalidate_lock
Use invalidate_lock instead of fuse's private i_mmap_sem. The intended
purpose is exactly the same. By this conversion we fix a long standing
race between hole punching and read(2) / readahead(2) paths that can
lead to stale page cache contents.

CC: Miklos Szeredi <miklos@szeredi.hu>
Reviewed-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2021-07-13 14:29:01 +02:00
Ira Weiny
2e29be2e49 fs/fuse: Remove unneeded kaddr parameter
fuse_dax_mem_range_init() does not need the address or the pfn of the
memory requested in dax_direct_access().  It is only calling direct
access to get the number of pages.

Remove the unused variables and stop requesting the kaddr and pfn from
dax_direct_access().

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Vivek Goyal <vgoyal@redhat.com>
Link: https://lore.kernel.org/r/20210525172428.3634316-2-ira.weiny@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-07-07 22:10:03 -07:00
Linus Torvalds
8e4f3e1517 fuse update for 5.14
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 =MDvD
 -----END PGP SIGNATURE-----

Merge tag 'fuse-update-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse

Pull fuse updates from Miklos Szeredi:

 - Fixes for virtiofs submounts

 - Misc fixes and cleanups

* tag 'fuse-update-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  virtiofs: Fix spelling mistakes
  fuse: use DIV_ROUND_UP helper macro for calculations
  fuse: fix illegal access to inode with reused nodeid
  fuse: allow fallocate(FALLOC_FL_ZERO_RANGE)
  fuse: Make fuse_fill_super_submount() static
  fuse: Switch to fc_mount() for submounts
  fuse: Call vfs_get_tree() for submounts
  fuse: add dedicated filesystem context ops for submounts
  virtiofs: propagate sync() to file server
  fuse: reject internal errno
  fuse: check connected before queueing on fpq->io
  fuse: ignore PG_workingset after stealing
  fuse: Fix infinite loop in sget_fc()
  fuse: Fix crash if superblock of submount gets killed early
  fuse: Fix crash in fuse_dentry_automount() error path
2021-07-06 11:17:41 -07:00
Linus Torvalds
d3acb15a3a Merge branch 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull iov_iter updates from Al Viro:
 "iov_iter cleanups and fixes.

  There are followups, but this is what had sat in -next this cycle. IMO
  the macro forest in there became much thinner and easier to follow..."

* 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (37 commits)
  csum_and_copy_to_pipe_iter(): leave handling of csum_state to caller
  clean up copy_mc_pipe_to_iter()
  pipe_zero(): we don't need no stinkin' kmap_atomic()...
  iov_iter: clean csum_and_copy_...() primitives up a bit
  copy_page_from_iter(): don't need kmap_atomic() for kvec/bvec cases
  copy_page_to_iter(): don't bother with kmap_atomic() for bvec/kvec cases
  iterate_xarray(): only of the first iteration we might get offset != 0
  pull handling of ->iov_offset into iterate_{iovec,bvec,xarray}
  iov_iter: make iterator callbacks use base and len instead of iovec
  iov_iter: make the amount already copied available to iterator callbacks
  iov_iter: get rid of separate bvec and xarray callbacks
  iov_iter: teach iterate_{bvec,xarray}() about possible short copies
  iterate_bvec(): expand bvec.h macro forest, massage a bit
  iov_iter: unify iterate_iovec and iterate_kvec
  iov_iter: massage iterate_iovec and iterate_kvec to logics similar to iterate_bvec
  iterate_and_advance(): get rid of magic in case when n is 0
  csum_and_copy_to_iter(): massage into form closer to csum_and_copy_from_iter()
  iov_iter: replace iov_iter_copy_from_user_atomic() with iterator-advancing variant
  [xarray] iov_iter_npages(): just use DIV_ROUND_UP()
  iov_iter_npages(): don't bother with iterate_all_kinds()
  ...
2021-07-03 11:30:04 -07:00
Matthew Wilcox (Oracle)
3a6b216200 mm: move page dirtying prototypes from mm.h
These functions implement the address_space ->set_page_dirty operation and
should live in pagemap.h, not mm.h so that the rest of the kernel doesn't
get funny ideas about calling them directly.

Link: https://lkml.kernel.org/r/20210615162342.1669332-7-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:48 -07:00
Matthew Wilcox (Oracle)
b82a96c925 fs: remove noop_set_page_dirty()
Use __set_page_dirty_no_writeback() instead.  This will set the dirty bit
on the page, which will be used to avoid calling set_page_dirty() in the
future.  It will have no effect on actually writing the page back, as the
pages are not on any LRU lists.

[akpm@linux-foundation.org: export __set_page_dirty_no_writeback() to modules]

Link: https://lkml.kernel.org/r/20210615162342.1669332-6-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:48 -07:00
Zheng Yongjun
c4e0cd4e0c virtiofs: Fix spelling mistakes
Fix some spelling mistakes in comments:
refernce  ==> reference
happnes  ==> happens
threhold  ==> threshold
splitted  ==> split
mached  ==> matched

Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-06-22 09:15:36 +02:00
Wu Bo
6c88632be3 fuse: use DIV_ROUND_UP helper macro for calculations
Replace open coded divisor calculations with the DIV_ROUND_UP kernel macro
for better readability.

Signed-off-by: Wu Bo <wubo40@huawei.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-06-22 09:15:36 +02:00
Amir Goldstein
15db16837a fuse: fix illegal access to inode with reused nodeid
Server responds to LOOKUP and other ops (READDIRPLUS/CREATE/MKNOD/...)
with ourarg containing nodeid and generation.

If a fuse inode is found in inode cache with the same nodeid but different
generation, the existing fuse inode should be unhashed and marked "bad" and
a new inode with the new generation should be hashed instead.

This can happen, for example, with passhrough fuse filesystem that returns
the real filesystem ino/generation on lookup and where real inode numbers
can get recycled due to real files being unlinked not via the fuse
passthrough filesystem.

With current code, this situation will not be detected and an old fuse
dentry that used to point to an older generation real inode, can be used to
access a completely new inode, which should be accessed only via the new
dentry.

Note that because the FORGET message carries the nodeid w/o generation, the
server should wait to get FORGET counts for the nlookup counts of the old
and reused inodes combined, before it can free the resources associated to
that nodeid.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-06-22 09:15:36 +02:00
Richard W.M. Jones
6b1bdb56b1 fuse: allow fallocate(FALLOC_FL_ZERO_RANGE)
The current fuse module filters out fallocate(FALLOC_FL_ZERO_RANGE)
returning -EOPNOTSUPP.  libnbd's nbdfuse would like to translate
FALLOC_FL_ZERO_RANGE requests into the NBD command
NBD_CMD_WRITE_ZEROES which allows NBD servers that support it to do
zeroing efficiently.

This commit treats this flag exactly like FALLOC_FL_PUNCH_HOLE.

A way to test this, requiring fuse >= 3, nbdkit >= 1.8 and the latest
nbdfuse from https://gitlab.com/nbdkit/libnbd/-/tree/master/fuse is to
create a file containing some data and "mirror" it to a fuse file:

  $ dd if=/dev/urandom of=disk.img bs=1M count=1
  $ nbdkit file disk.img
  $ touch mirror.img
  $ nbdfuse mirror.img nbd://localhost &

(mirror.img -> nbdfuse -> NBD over loopback -> nbdkit -> disk.img)

You can then run commands such as:

  $ fallocate -z -o 1024 -l 1024 mirror.img

and check that the content of the original file ("disk.img") stays
synchronized.  To show NBD commands, export LIBNBD_DEBUG=1 before
running nbdfuse.  To clean up:

  $ fusermount3 -u mirror.img
  $ killall nbdkit

Signed-off-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-06-22 09:15:36 +02:00
Greg Kurz
1b53991737 fuse: Make fuse_fill_super_submount() static
This function used to be called from fuse_dentry_automount(). This code
was moved to fuse_get_tree_submount() in the same file since then. It
is unlikely there will ever be another user. No need to be extern in
this case.

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-06-22 09:15:35 +02:00
Greg Kurz
29e0e4df9d fuse: Switch to fc_mount() for submounts
fc_mount() already handles the vfs_get_tree(), sb->s_umount
unlocking and vfs_create_mount() sequence. Using it greatly
simplifies fuse_dentry_automount().

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-06-22 09:15:35 +02:00
Greg Kurz
266eb3f2fa fuse: Call vfs_get_tree() for submounts
We recently fixed an infinite loop by setting the SB_BORN flag on
submounts along with the write barrier needed by super_cache_count().
This is the job of vfs_get_tree() and FUSE shouldn't have to care
about the barrier at all.

Split out some code from fuse_dentry_automount() to the dedicated
fuse_get_tree_submount() handler for submounts and call vfs_get_tree().

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-06-22 09:15:35 +02:00
Greg Kurz
fe0a7bd81b fuse: add dedicated filesystem context ops for submounts
The creation of a submount is open-coded in fuse_dentry_automount().
This brings a lot of complexity and we recently had to fix bugs
because we weren't setting SB_BORN or because we were unlocking
sb->s_umount before sb was fully configured. Most of these could
have been avoided by using the mount API instead of open-coding.

Basically, this means coming up with a proper ->get_tree()
implementation for submounts and call vfs_get_tree(), or better
fc_mount().

The creation of the superblock for submounts is quite different from
the root mount. Especially, it doesn't require to allocate a FUSE
filesystem context, nor to parse parameters.

Introduce a dedicated context ops for submounts to make this clear.
This is just a placeholder for now, fuse_get_tree_submount() will
be populated in a subsequent patch.

Only visible change is that we stop allocating/freeing a useless FUSE
filesystem context with submounts.

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-06-22 09:15:35 +02:00
Greg Kurz
2d82ab251e virtiofs: propagate sync() to file server
Even if POSIX doesn't mandate it, linux users legitimately expect sync() to
flush all data and metadata to physical storage when it is located on the
same system.  This isn't happening with virtiofs though: sync() inside the
guest returns right away even though data still needs to be flushed from
the host page cache.

This is easily demonstrated by doing the following in the guest:

$ dd if=/dev/zero of=/mnt/foo bs=1M count=5K ; strace -T -e sync sync
5120+0 records in
5120+0 records out
5368709120 bytes (5.4 GB, 5.0 GiB) copied, 5.22224 s, 1.0 GB/s
sync()                                  = 0 <0.024068>

and start the following in the host when the 'dd' command completes
in the guest:

$ strace -T -e fsync /usr/bin/sync virtiofs/foo
fsync(3)                                = 0 <10.371640>

There are no good reasons not to honor the expected behavior of sync()
actually: it gives an unrealistic impression that virtiofs is super fast
and that data has safely landed on HW, which isn't the case obviously.

Implement a ->sync_fs() superblock operation that sends a new FUSE_SYNCFS
request type for this purpose.  Provision a 64-bit placeholder for possible
future extensions.  Since the file server cannot handle the wait == 0 case,
we skip it to avoid a gratuitous roundtrip.  Note that this is
per-superblock: a FUSE_SYNCFS is send for the root mount and for each
submount.

Like with FUSE_FSYNC and FUSE_FSYNCDIR, lack of support for FUSE_SYNCFS in
the file server is treated as permanent success.  This ensures
compatibility with older file servers: the client will get the current
behavior of sync() not being propagated to the file server.

Note that such an operation allows the file server to DoS sync().  Since a
typical FUSE file server is an untrusted piece of software running in
userspace, this is disabled by default.  Only enable it with virtiofs for
now since virtiofsd is supposedly trusted by the guest kernel.

Reported-by: Robert Krawitz <rlk@redhat.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-06-22 09:15:35 +02:00
Miklos Szeredi
49221cf86d fuse: reject internal errno
Don't allow userspace to report errors that could be kernel-internal.

Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com>
Fixes: 334f485df8 ("[PATCH] FUSE - device functions")
Cc: <stable@vger.kernel.org> # v2.6.14
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-06-22 09:15:35 +02:00
Miklos Szeredi
80ef08670d fuse: check connected before queueing on fpq->io
A request could end up on the fpq->io list after fuse_abort_conn() has
reset fpq->connected and aborted requests on that list:

Thread-1			  Thread-2
========			  ========
->fuse_simple_request()           ->shutdown
  ->__fuse_request_send()
    ->queue_request()		->fuse_abort_conn()
->fuse_dev_do_read()                ->acquire(fpq->lock)
  ->wait_for(fpq->lock) 	  ->set err to all req's in fpq->io
				  ->release(fpq->lock)
  ->acquire(fpq->lock)
  ->add req to fpq->io

After the userspace copy is done the request will be ended, but
req->out.h.error will remain uninitialized.  Also the copy might block
despite being already aborted.

Fix both issues by not allowing the request to be queued on the fpq->io
list after fuse_abort_conn() has processed this list.

Reported-by: Pradeep P V K <pragalla@codeaurora.org>
Fixes: fd22d62ed0 ("fuse: no fc->lock for iqueue parts")
Cc: <stable@vger.kernel.org> # v4.2
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-06-22 09:15:35 +02:00
Miklos Szeredi
b89ecd60d3 fuse: ignore PG_workingset after stealing
Fix the "fuse: trying to steal weird page" warning.

Description from Johannes Weiner:

  "Think of it as similar to PG_active. It's just another usage/heat
   indicator of file and anon pages on the reclaim LRU that, unlike
   PG_active, persists across deactivation and even reclaim (we store it in
   the page cache / swapper cache tree until the page refaults).

   So if fuse accepts pages that can legally have PG_active set,
   PG_workingset is fine too."

Reported-by: Thomas Lindroth <thomas.lindroth@gmail.com>
Fixes: 1899ad18c6 ("mm: workingset: tell cache transitions from workingset thrashing")
Cc: <stable@vger.kernel.org> # v4.20
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-06-18 21:16:42 +02:00
Al Viro
f0b65f39ac iov_iter: replace iov_iter_copy_from_user_atomic() with iterator-advancing variant
Replacement is called copy_page_from_iter_atomic(); unlike the old primitive the
callers do *not* need to do iov_iter_advance() after it.  In case when they end
up consuming less than they'd been given they need to do iov_iter_revert() on
everything they had not consumed.  That, however, needs to be done only on slow
paths.

All in-tree callers converted.  And that kills the last user of iterate_all_kinds()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-06-10 11:45:14 -04:00
Greg Kurz
e4a9ccdd1c fuse: Fix infinite loop in sget_fc()
We don't set the SB_BORN flag on submounts. This is wrong as these
superblocks are then considered as partially constructed or dying
in the rest of the code and can break some assumptions.

One such case is when you have a virtiofs filesystem with submounts
and you try to mount it again : virtio_fs_get_tree() tries to obtain
a superblock with sget_fc(). The logic in sget_fc() is to loop until
it has either found an existing matching superblock with SB_BORN set
or to create a brand new one. It is assumed that a superblock without
SB_BORN is transient and the loop is restarted. Forgetting to set
SB_BORN on submounts hence causes sget_fc() to retry forever.

Setting SB_BORN requires special care, i.e. a write barrier for
super_cache_count() which can check SB_BORN without taking any lock.
We should call vfs_get_tree() to deal with that but this requires
to have a proper ->get_tree() implementation for submounts, which
is a bigger piece of work. Go for a simple bug fix in the meatime.

Fixes: bf109c6404 ("fuse: implement crossmounts")
Cc: stable@vger.kernel.org # v5.10+
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-06-09 15:33:40 +02:00
Greg Kurz
e3a43f2a95 fuse: Fix crash if superblock of submount gets killed early
As soon as fuse_dentry_automount() does up_write(&sb->s_umount), the
superblock can theoretically be killed. If this happens before the
submount was added to the &fc->mounts list, fuse_mount_remove() later
crashes in list_del_init() because it assumes the submount to be
already there.

Add the submount before dropping sb->s_umount to fix the inconsistency.
It is okay to nest fc->killsb under sb->s_umount, we already do this
on the ->kill_sb() path.

Signed-off-by: Greg Kurz <groug@kaod.org>
Fixes: bf109c6404 ("fuse: implement crossmounts")
Cc: stable@vger.kernel.org # v5.10+
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-06-09 15:33:40 +02:00
Greg Kurz
d92d88f056 fuse: Fix crash in fuse_dentry_automount() error path
If fuse_fill_super_submount() returns an error, the error path
triggers a crash:

[   26.206673] BUG: kernel NULL pointer dereference, address: 0000000000000000
[...]
[   26.226362] RIP: 0010:__list_del_entry_valid+0x25/0x90
[...]
[   26.247938] Call Trace:
[   26.248300]  fuse_mount_remove+0x2c/0x70 [fuse]
[   26.248892]  virtio_kill_sb+0x22/0x160 [virtiofs]
[   26.249487]  deactivate_locked_super+0x36/0xa0
[   26.250077]  fuse_dentry_automount+0x178/0x1a0 [fuse]

The crash happens because fuse_mount_remove() assumes that the FUSE
mount was already added to list under the FUSE connection, but this
only done after fuse_fill_super_submount() has returned success.

This means that until fuse_fill_super_submount() has returned success,
the FUSE mount isn't actually owned by the superblock. We should thus
reclaim ownership by clearing sb->s_fs_info, which will skip the call
to fuse_mount_remove(), and perform rollback, like virtio_fs_get_tree()
already does for the root sb.

Fixes: bf109c6404 ("fuse: implement crossmounts")
Cc: stable@vger.kernel.org # v5.10+
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-06-09 15:33:40 +02:00
Al Viro
8959a23924 fuse_fill_write_pages(): don't bother with iov_iter_single_seg_count()
another rudiment of fault-in originally having been limited to the
first segment, same as in generic_perform_write() and friends.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-06-03 10:34:55 -04:00
Linus Torvalds
27787ba3fa Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc vfs updates from Al Viro:
 "Assorted stuff all over the place"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  useful constants: struct qstr for ".."
  hostfs_open(): don't open-code file_dentry()
  whack-a-mole: kill strlen_user() (again)
  autofs: should_expire() argument is guaranteed to be positive
  apparmor:match_mn() - constify devpath argument
  buffer: a small optimization in grow_buffers
  get rid of autofs_getpath()
  constify dentry argument of dentry_path()/dentry_path_raw()
2021-05-02 09:14:01 -07:00
Linus Torvalds
9ec1efbf9d fuse update for 5.13
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Merge tag 'fuse-update-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse

Pull fuse updates from Miklos Szeredi:

 - Fix a page locking bug in write (introduced in 2.6.26)

 - Allow sgid bit to be killed in setacl()

 - Miscellaneous fixes and cleanups

* tag 'fuse-update-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  cuse: simplify refcount
  cuse: prevent clone
  virtiofs: fix userns
  virtiofs: remove useless function
  virtiofs: split requests that exceed virtqueue size
  virtiofs: fix memory leak in virtio_fs_probe()
  fuse: invalidate attrs when page writeback completes
  fuse: add a flag FUSE_SETXATTR_ACL_KILL_SGID to kill SGID
  fuse: extend FUSE_SETXATTR request
  fuse: fix matching of FUSE_DEV_IOC_CLONE command
  fuse: fix a typo
  fuse: don't zero pages twice
  fuse: fix typo for fuse_conn.max_pages comment
  fuse: fix write deadlock
2021-04-30 15:23:16 -07:00
Linus Torvalds
a4f7fae101 Merge branch 'miklos.fileattr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull fileattr conversion updates from Miklos Szeredi via Al Viro:
 "This splits the handling of FS_IOC_[GS]ETFLAGS from ->ioctl() into a
  separate method.

  The interface is reasonably uniform across the filesystems that
  support it and gives nice boilerplate removal"

* 'miklos.fileattr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (23 commits)
  ovl: remove unneeded ioctls
  fuse: convert to fileattr
  fuse: add internal open/release helpers
  fuse: unsigned open flags
  fuse: move ioctl to separate source file
  vfs: remove unused ioctl helpers
  ubifs: convert to fileattr
  reiserfs: convert to fileattr
  ocfs2: convert to fileattr
  nilfs2: convert to fileattr
  jfs: convert to fileattr
  hfsplus: convert to fileattr
  efivars: convert to fileattr
  xfs: convert to fileattr
  orangefs: convert to fileattr
  gfs2: convert to fileattr
  f2fs: convert to fileattr
  ext4: convert to fileattr
  ext2: convert to fileattr
  btrfs: convert to fileattr
  ...
2021-04-27 11:18:24 -07:00
Linus Torvalds
d1466bc583 Merge branch 'work.inode-type-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs inode type handling updates from Al Viro:
 "We should never change the type bits of ->i_mode or the method tables
  (->i_op and ->i_fop) of a live inode.

  Unfortunately, not all filesystems took care to prevent that"

* 'work.inode-type-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  spufs: fix bogosity in S_ISGID handling
  9p: missing chunk of "fs/9p: Don't update file type when updating file attributes"
  openpromfs: don't do unlock_new_inode() until the new inode is set up
  hostfs_mknod(): don't bother with init_special_inode()
  cifs: have cifs_fattr_to_inode() refuse to change type on live inode
  cifs: have ->mkdir() handle race with another client sanely
  do_cifs_create(): don't set ->i_mode of something we had not created
  gfs2: be careful with inode refresh
  ocfs2_inode_lock_update(): make sure we don't change the type bits of i_mode
  orangefs_inode_is_stale(): i_mode type bits do *not* form a bitmap...
  vboxsf: don't allow to change the inode type
  afs: Fix updating of i_mode due to 3rd party change
  ceph: don't allow type or device number to change on non-I_NEW inodes
  ceph: fix up error handling with snapdirs
  new helper: inode_wrong_type()
2021-04-27 10:57:42 -07:00
Al Viro
80e5d1ff5d useful constants: struct qstr for ".."
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-04-15 22:36:45 -04:00
Miklos Szeredi
3c9c14338c cuse: simplify refcount
Put extra reference early in cuse_channel_open().

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-04-14 10:40:58 +02:00
Miklos Szeredi
8217673d07 cuse: prevent clone
For cloned connections cuse_channel_release() will be called more than
once, resulting in use after free.

Prevent device cloning for CUSE, which does not make sense at this point,
and highly unlikely to be used in real life.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-04-14 10:40:58 +02:00
Miklos Szeredi
0a7419c68a virtiofs: fix userns
get_user_ns() is done twice (once in virtio_fs_get_tree() and once in
fuse_conn_init()), resulting in a reference leak.

Also looks better to use fsc->user_ns (which *should* be the
current_user_ns() at this point).

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-04-14 10:40:58 +02:00
Jiapeng Chong
07595bfa24 virtiofs: remove useless function
Fix the following clang warning:

fs/fuse/virtio_fs.c:130:35: warning: unused function 'vq_to_fpq'
[-Wunused-function].

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-04-14 10:40:57 +02:00
Connor Kuehl
a7f0d7aab0 virtiofs: split requests that exceed virtqueue size
If an incoming FUSE request can't fit on the virtqueue, the request is
placed onto a workqueue so a worker can try to resubmit it later where
there will (hopefully) be space for it next time.

This is fine for requests that aren't larger than a virtqueue's maximum
capacity.  However, if a request's size exceeds the maximum capacity of the
virtqueue (even if the virtqueue is empty), it will be doomed to a life of
being placed on the workqueue, removed, discovered it won't fit, and placed
on the workqueue yet again.

Furthermore, from section 2.6.5.3.1 (Driver Requirements: Indirect
Descriptors) of the virtio spec:

  "A driver MUST NOT create a descriptor chain longer than the Queue
  Size of the device."

To fix this, limit the number of pages FUSE will use for an overall
request.  This way, each request can realistically fit on the virtqueue
when it is decomposed into a scattergather list and avoid violating section
2.6.5.3.1 of the virtio spec.

Signed-off-by: Connor Kuehl <ckuehl@redhat.com>
Reviewed-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-04-14 10:40:57 +02:00
Luis Henriques
c79c5e0178 virtiofs: fix memory leak in virtio_fs_probe()
When accidentally passing twice the same tag to qemu, kmemleak ended up
reporting a memory leak in virtiofs.  Also, looking at the log I saw the
following error (that's when I realised the duplicated tag):

  virtiofs: probe of virtio5 failed with error -17

Here's the kmemleak log for reference:

unreferenced object 0xffff888103d47800 (size 1024):
  comm "systemd-udevd", pid 118, jiffies 4294893780 (age 18.340s)
  hex dump (first 32 bytes):
    00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00  .....N..........
    ff ff ff ff ff ff ff ff 80 90 02 a0 ff ff ff ff  ................
  backtrace:
    [<000000000ebb87c1>] virtio_fs_probe+0x171/0x7ae [virtiofs]
    [<00000000f8aca419>] virtio_dev_probe+0x15f/0x210
    [<000000004d6baf3c>] really_probe+0xea/0x430
    [<00000000a6ceeac8>] device_driver_attach+0xa8/0xb0
    [<00000000196f47a7>] __driver_attach+0x98/0x140
    [<000000000b20601d>] bus_for_each_dev+0x7b/0xc0
    [<00000000399c7b7f>] bus_add_driver+0x11b/0x1f0
    [<0000000032b09ba7>] driver_register+0x8f/0xe0
    [<00000000cdd55998>] 0xffffffffa002c013
    [<000000000ea196a2>] do_one_initcall+0x64/0x2e0
    [<0000000008f727ce>] do_init_module+0x5c/0x260
    [<000000003cdedab6>] __do_sys_finit_module+0xb5/0x120
    [<00000000ad2f48c6>] do_syscall_64+0x33/0x40
    [<00000000809526b5>] entry_SYSCALL_64_after_hwframe+0x44/0xae

Cc: stable@vger.kernel.org
Signed-off-by: Luis Henriques <lhenriques@suse.de>
Fixes: a62a8ef9d9 ("virtio-fs: add virtiofs filesystem")
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-04-14 10:40:57 +02:00
Vivek Goyal
3466958beb fuse: invalidate attrs when page writeback completes
In fuse when a direct/write-through write happens we invalidate attrs
because that might have updated mtime/ctime on server and cached
mtime/ctime will be stale.

What about page writeback path.  Looks like we don't invalidate attrs
there.  To be consistent, invalidate attrs in writeback path as well.  Only
exception is when writeback_cache is enabled.  In that case we strust local
mtime/ctime and there is no need to invalidate attrs.

Recently users started experiencing failure of xfstests generic/080,
geneirc/215 and generic/614 on virtiofs.  This happened only newer "stat"
utility and not older one.  This patch fixes the issue.

So what's the root cause of the issue.  Here is detailed explanation.

generic/080 test does mmap write to a file, closes the file and then checks
if mtime has been updated or not.  When file is closed, it leads to
flushing of dirty pages (and that should update mtime/ctime on server).
But we did not explicitly invalidate attrs after writeback finished.  Still
generic/080 passed so far and reason being that we invalidated atime in
fuse_readpages_end().  This is called in fuse_readahead() path and always
seems to trigger before mmaped write.

So after mmaped write when lstat() is called, it sees that atleast one of
the fields being asked for is invalid (atime) and that results in
generating GETATTR to server and mtime/ctime also get updated and test
passes.

But newer /usr/bin/stat seems to have moved to using statx() syscall now
(instead of using lstat()).  And statx() allows it to query only ctime or
mtime (and not rest of the basic stat fields).  That means when querying
for mtime, fuse_update_get_attr() sees that mtime is not invalid (only
atime is invalid).  So it does not generate a new GETATTR and fill stat
with cached mtime/ctime.  And that means updated mtime is not seen by
xfstest and tests start failing.

Invalidating attrs after writeback completion should solve this problem in
a generic manner.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-04-14 10:40:57 +02:00
Vivek Goyal
550a7d3bc0 fuse: add a flag FUSE_SETXATTR_ACL_KILL_SGID to kill SGID
When posix access ACL is set, it can have an effect on file mode and it can
also need to clear SGID if.

- None of caller's group/supplementary groups match file owner group.
AND
- Caller is not priviliged (No CAP_FSETID).

As of now fuser server is responsible for changing the file mode as
well. But it does not know whether to clear SGID or not.

So add a flag FUSE_SETXATTR_ACL_KILL_SGID and send this info with SETXATTR
to let file server know that sgid needs to be cleared as well.

Reported-by: Luis Henriques <lhenriques@suse.de>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-04-14 10:40:57 +02:00
Vivek Goyal
52a4c95f4d fuse: extend FUSE_SETXATTR request
Fuse client needs to send additional information to file server when it
calls SETXATTR(system.posix_acl_access), so add extra flags field to the
structure.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-04-14 10:40:57 +02:00
Alessio Balsini
6076f5f341 fuse: fix matching of FUSE_DEV_IOC_CLONE command
With commit f8425c9396 ("fuse: 32-bit user space ioctl compat for fuse
device") the matching constraints for the FUSE_DEV_IOC_CLONE ioctl command
are relaxed, limited to the testing of command type and number.  As Arnd
noticed, this is wrong as it wouldn't ensure the correctness of the data
size or direction for the received FUSE device ioctl.

Fix by bringing back the comparison of the ioctl received by the FUSE
device to the originally generated FUSE_DEV_IOC_CLONE.

Fixes: f8425c9396 ("fuse: 32-bit user space ioctl compat for fuse device")
Reported-by: Arnd Bergmann <arnd@kernel.org>
Signed-off-by: Alessio Balsini <balsini@android.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-04-14 10:40:57 +02:00
Bhaskar Chowdhury
aa6ff555f0 fuse: fix a typo
s/reponsible/responsible/

Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-04-14 10:40:57 +02:00
Miklos Szeredi
a73d47f577 fuse: don't zero pages twice
All callers of fuse_short_read already set the .page_zeroing flag, so no
need to do the tail zeroing again.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-04-14 10:40:56 +02:00
Connor Kuehl
4b91459ad2 fuse: fix typo for fuse_conn.max_pages comment
'Maxmum' -> 'Maximum'

Signed-off-by: Connor Kuehl <ckuehl@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-04-14 10:40:56 +02:00
Vivek Goyal
4f06dd92b5 fuse: fix write deadlock
There are two modes for write(2) and friends in fuse:

a) write through (update page cache, send sync WRITE request to userspace)

b) buffered write (update page cache, async writeout later)

The write through method kept all the page cache pages locked that were
used for the request.  Keeping more than one page locked is deadlock prone
and Qian Cai demonstrated this with trinity fuzzing.

The reason for keeping the pages locked is that concurrent mapped reads
shouldn't try to pull possibly stale data into the page cache.

For full page writes, the easy way to fix this is to make the cached page
be the authoritative source by marking the page PG_uptodate immediately.
After this the page can be safely unlocked, since mapped/cached reads will
take the written data from the cache.

Concurrent mapped writes will now cause data in the original WRITE request
to be updated; this however doesn't cause any data inconsistency and this
scenario should be exceedingly rare anyway.

If the WRITE request returns with an error in the above case, currently the
page is not marked uptodate; this means that a concurrent read will always
read consistent data.  After this patch the page is uptodate between
writing to the cache and receiving the error: there's window where a cached
read will read the wrong data.  While theoretically this could be a
regression, it is unlikely to be one in practice, since this is normal for
buffered writes.

In case of a partial page write to an already uptodate page the locking is
also unnecessary, with the above caveats.

Partial write of a not uptodate page still needs to be handled.  One way
would be to read the complete page before doing the write.  This is not
possible, since it might break filesystems that don't expect any READ
requests when the file was opened O_WRONLY.

The other solution is to serialize the synchronous write with reads from
the partial pages.  The easiest way to do this is to keep the partial pages
locked.  The problem is that a write() may involve two such pages (one head
and one tail).  This patch fixes it by only locking the partial tail page.
If there's a partial head page as well, then split that off as a separate
WRITE request.

Reported-by: Qian Cai <cai@lca.pw>
Link: https://lore.kernel.org/linux-fsdevel/4794a3fa3742a5e84fb0f934944204b55730829b.camel@lca.pw/
Fixes: ea9b9907b8 ("fuse: implement perform_write")
Cc: <stable@vger.kernel.org> # v2.6.26
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-04-14 10:40:56 +02:00
Miklos Szeredi
72227eac17 fuse: convert to fileattr
Since fuse just passes ioctl args through to/from server, converting to the
fileattr API is more involved, than most other filesystems.

Both .fileattr_set() and .fileattr_get() need to obtain an open file to
operate on.  The simplest way is with the following sequence:

  FUSE_OPEN
  FUSE_IOCTL
  FUSE_RELEASE

If this turns out to be a performance problem, it could be optimized for
the case when there's already a file (any file) open for the inode.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-04-12 15:04:30 +02:00
Miklos Szeredi
b9d54c6f29 fuse: add internal open/release helpers
Clean out 'struct file' from internal helpers.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-04-12 15:04:30 +02:00
Miklos Szeredi
54d601cb67 fuse: unsigned open flags
Release helpers used signed int.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-04-12 15:04:30 +02:00
Miklos Szeredi
9ac29fd3f8 fuse: move ioctl to separate source file
Next patch will expand ioctl code and fuse/file.c is large enough as it is.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-04-12 15:04:30 +02:00
Alessio Balsini
f8425c9396 fuse: 32-bit user space ioctl compat for fuse device
With a 64-bit kernel build the FUSE device cannot handle ioctl requests
coming from 32-bit user space.  This is due to the ioctl command
translation that generates different command identifiers that thus cannot
be used for direct comparisons without proper manipulation.

Explicitly extract type and number from the ioctl command to enable 32-bit
user space compatibility on 64-bit kernel builds.

Signed-off-by: Alessio Balsini <balsini@android.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-03-16 15:20:16 +01:00
Al Viro
6e3e2c4362 new helper: inode_wrong_type()
inode_wrong_type(inode, mode) returns true if setting inode->i_mode
to given value would've changed the inode type.  We have enough of
those checks open-coded to make a helper worthwhile.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-03-08 10:19:35 -05:00
Vivek Goyal
3f9b9efd82 virtiofs: Fail dax mount if device does not support it
Right now "mount -t virtiofs -o dax myfs /mnt/virtiofs" succeeds even
if filesystem deivce does not have a cache window and hence DAX can't
be supported.

This gives a false sense to user that they are using DAX with virtiofs
but fact of the matter is that they are not.

Fix this by returning error if dax can't be supported and user has asked
for it.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-03-05 15:46:47 +01:00
Amir Goldstein
775c5033a0 fuse: fix live lock in fuse_iget()
Commit 5d069dbe8a ("fuse: fix bad inode") replaced make_bad_inode()
in fuse_iget() with a private implementation fuse_make_bad().

The private implementation fails to remove the bad inode from inode
cache, so the retry loop with iget5_locked() finds the same bad inode
and marks it bad forever.

kmsg snip:

[ ] rcu: INFO: rcu_sched self-detected stall on CPU
...
[ ]  ? bit_wait_io+0x50/0x50
[ ]  ? fuse_init_file_inode+0x70/0x70
[ ]  ? find_inode.isra.32+0x60/0xb0
[ ]  ? fuse_init_file_inode+0x70/0x70
[ ]  ilookup5_nowait+0x65/0x90
[ ]  ? fuse_init_file_inode+0x70/0x70
[ ]  ilookup5.part.36+0x2e/0x80
[ ]  ? fuse_init_file_inode+0x70/0x70
[ ]  ? fuse_inode_eq+0x20/0x20
[ ]  iget5_locked+0x21/0x80
[ ]  ? fuse_inode_eq+0x20/0x20
[ ]  fuse_iget+0x96/0x1b0

Fixes: 5d069dbe8a ("fuse: fix bad inode")
Cc: stable@vger.kernel.org # 5.10+
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-03-04 13:36:46 +01:00
Baolin Wang
1f7ef65774 mm/filemap: remove unused parameter and change to void type for replace_page_cache_page()
Since commit 74d609585d ("page cache: Add and replace pages using the
XArray") was merged, the replace_page_cache_page() can not fail and always
return 0, we can remove the redundant return value and void it.  Moreover
remove the unused gfp_mask.

Link: https://lkml.kernel.org/r/609c30e5274ba15d8b90c872fd0d8ac437a9b2bb.1610071401.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:27 -08:00
Christian Brauner
549c729771
fs: make helpers idmap mount aware
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>
2021-01-24 14:27:20 +01:00
Christian Brauner
0d56a4518d
stat: handle idmapped mounts
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>
2021-01-24 14:27:17 +01:00
Christian Brauner
e65ce2a50c
acl: handle idmapped mounts
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>
2021-01-24 14:27:17 +01:00
Christian Brauner
2f221d6f7b
attr: handle idmapped mounts
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>
2021-01-24 14:27:16 +01:00
Christian Brauner
47291baa8d
namei: make permission helpers idmapped mount aware
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>
2021-01-24 14:27:16 +01:00
Miklos Szeredi
5d069dbe8a fuse: fix bad inode
Jan Kara's analysis of the syzbot report (edited):

  The reproducer opens a directory on FUSE filesystem, it then attaches
  dnotify mark to the open directory.  After that a fuse_do_getattr() call
  finds that attributes returned by the server are inconsistent, and calls
  make_bad_inode() which, among other things does:

          inode->i_mode = S_IFREG;

  This then confuses dnotify which doesn't tear down its structures
  properly and eventually crashes.

Avoid calling make_bad_inode() on a live inode: switch to a private flag on
the fuse inode.  Also add the test to ops which the bad_inode_ops would
have caught.

This bug goes back to the initial merge of fuse in 2.6.14...

Reported-by: syzbot+f427adf9324b92652ccc@syzkaller.appspotmail.com
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Tested-by: Jan Kara <jack@suse.cz>
Cc: <stable@vger.kernel.org>
2020-12-10 15:33:14 +01:00
Vivek Goyal
9d769e6aa2 fuse: support SB_NOSEC flag to improve write performance
Virtiofs can be slow with small writes if xattr are enabled and we are
doing cached writes (No direct I/O).  Ganesh Mahalingam noticed this.

Some debugging showed that file_remove_privs() is called in cached write
path on every write.  And everytime it calls security_inode_need_killpriv()
which results in call to __vfs_getxattr(XATTR_NAME_CAPS).  And this goes to
file server to fetch xattr.  This extra round trip for every write slows
down writes tremendously.

Normally to avoid paying this penalty on every write, vfs has the notion of
caching this information in inode (S_NOSEC).  So vfs sets S_NOSEC, if
filesystem opted for it using super block flag SB_NOSEC.  And S_NOSEC is
cleared when setuid/setgid bit is set or when security xattr is set on
inode so that next time a write happens, we check inode again for clearing
setuid/setgid bits as well clear any security.capability xattr.

This seems to work well for local file systems but for remote file systems
it is possible that VFS does not have full picture and a different client
sets setuid/setgid bit or security.capability xattr on file and that means
VFS information about S_NOSEC on another client will be stale.  So for
remote filesystems SB_NOSEC was disabled by default.

Commit 9e1f1de02c ("more conservative S_NOSEC handling") mentioned that
these filesystems can still make use of SB_NOSEC as long as they clear
S_NOSEC when they are refreshing inode attriutes from server.

So this patch tries to enable SB_NOSEC on fuse (regular fuse as well as
virtiofs).  And clear SB_NOSEC when we are refreshing inode attributes.

This is enabled only if server supports FUSE_HANDLE_KILLPRIV_V2.  This says
that server will clear setuid/setgid/security.capability on
chown/truncate/write as apporpriate.

This should provide tighter coherency because now suid/sgid/
security.capability will be cleared even if fuse client cache has not seen
these attrs.

Basic idea is that fuse client will trigger suid/sgid/security.capability
clearing based on its attr cache.  But even if cache has gone stale, it is
fine because FUSE_HANDLE_KILLPRIV_V2 will make sure WRITE clear
suid/sgid/security.capability.

We make this change only if server supports FUSE_HANDLE_KILLPRIV_V2.  This
should make sure that existing filesystems which might be relying on
seucurity.capability always being queried from server are not impacted.

This tighter coherency relies on WRITE showing up on server (and not being
cached in guest).  So writeback_cache mode will not provide that tight
coherency and it is not recommended to use two together.  Having said that
it might work reasonably well for lot of use cases.

This change improves random write performance very significantly.  Running
virtiofsd with cache=auto and following fio command:

fio --ioengine=libaio --direct=1  --name=test --filename=/mnt/virtiofs/random_read_write.fio --bs=4k --iodepth=64 --size=4G --readwrite=randwrite

Bandwidth increases from around 50MB/s to around 250MB/s as a result of
applying this patch.  So improvement is very significant.

Link: https://github.com/kata-containers/runtime/issues/2815
Reported-by: "Mahalingam, Ganesh" <ganesh.mahalingam@intel.com>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-11-11 17:22:33 +01:00
Vivek Goyal
643a666a89 fuse: add a flag FUSE_OPEN_KILL_SUIDGID for open() request
With FUSE_HANDLE_KILLPRIV_V2 support, server will need to kill suid/sgid/
security.capability on open(O_TRUNC), if server supports
FUSE_ATOMIC_O_TRUNC.

But server needs to kill suid/sgid only if caller does not have CAP_FSETID.
Given server does not have this information, client needs to send this info
to server.

So add a flag FUSE_OPEN_KILL_SUIDGID to fuse_open_in request which tells
server to kill suid/sgid (only if group execute is set).

This flag is added to the FUSE_OPEN request, as well as the FUSE_CREATE
request if the create was non-exclusive, since that might result in an
existing file being opened/truncated.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-11-11 17:22:33 +01:00
Vivek Goyal
8981bdfda7 fuse: don't send ATTR_MODE to kill suid/sgid for handle_killpriv_v2
If client does a write() on a suid/sgid file, VFS will first call
fuse_setattr() with ATTR_KILL_S[UG]ID set.  This requires sending setattr
to file server with ATTR_MODE set to kill suid/sgid.  But to do that client
needs to know latest mode otherwise it is racy.

To reduce the race window, current code first call fuse_do_getattr() to get
latest ->i_mode and then resets suid/sgid bits and sends rest to server
with setattr(ATTR_MODE).  This does not reduce the race completely but
narrows race window significantly.

With fc->handle_killpriv_v2 enabled, it should be possible to remove this
race completely.  Do not kill suid/sgid with ATTR_MODE at all.  It will be
killed by server when WRITE request is sent to server soon.  This is
similar to fc->handle_killpriv logic.  V2 is just more refined version of
protocol.  Hence this patch does not send ATTR_MODE to kill suid/sgid if
fc->handle_killpriv_v2 is enabled.

This creates an issue if fc->writeback_cache is enabled.  In that case
WRITE can be cached in guest and server might not see WRITE request and
hence will not kill suid/sgid.  Miklos suggested that in such cases, we
should fallback to a writethrough WRITE instead and that will generate
WRITE request and kill suid/sgid.  This patch implements that too.

But this relies on client seeing the suid/sgid set.  If another client sets
suid/sgid and this client does not see it immideately, then we will not
fallback to writethrough WRITE.  So this is one limitation with both
fc->handle_killpriv_v2 and fc->writeback_cache enabled.  Both the options
are not fully compatible.  But might be good enough for many use cases.

Note: This patch is not checking whether security.capability is set or not
      when falling back to writethrough path.  If suid/sgid is not set and
      only security.capability is set, that will be taken care of by
      file_remove_privs() call in ->writeback_cache path.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-11-11 17:22:33 +01:00
Vivek Goyal
3179216135 fuse: setattr should set FATTR_KILL_SUIDGID
If fc->handle_killpriv_v2 is enabled, we expect file server to clear
suid/sgid/security.capbility upon chown/truncate/write as appropriate.

Upon truncate (ATTR_SIZE), suid/sgid are cleared only if caller does not
have CAP_FSETID.  File server does not know whether caller has CAP_FSETID
or not.  Hence set FATTR_KILL_SUIDGID upon truncate to let file server know
that caller does not have CAP_FSETID and it should kill suid/sgid as
appropriate.

On chown (ATTR_UID/ATTR_GID) suid/sgid need to be cleared irrespective of
capabilities of calling process, so set FATTR_KILL_SUIDGID unconditionally
in that case.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-11-11 17:22:33 +01:00
Vivek Goyal
b866739596 fuse: set FUSE_WRITE_KILL_SUIDGID in cached write path
With HANDLE_KILLPRIV_V2, server will need to kill suid/sgid if caller does
not have CAP_FSETID.  We already have a flag FUSE_WRITE_KILL_SUIDGID in
WRITE request and we already set it in direct I/O path.

To make it work in cached write path also, start setting
FUSE_WRITE_KILL_SUIDGID in this path too.

Set it only if fc->handle_killpriv_v2 is set.  Otherwise client is
responsible for kill suid/sgid.

In case of direct I/O we set FUSE_WRITE_KILL_SUIDGID unconditionally
because we don't call file_remove_privs() in that path (with cache=none
option).

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-11-11 17:22:33 +01:00
Miklos Szeredi
10c52c84e3 fuse: rename FUSE_WRITE_KILL_PRIV to FUSE_WRITE_KILL_SUIDGID
Kernel has:
ATTR_KILL_PRIV -> clear "security.capability"
ATTR_KILL_SUID -> clear S_ISUID
ATTR_KILL_SGID -> clear S_ISGID if executable

Fuse has:
FUSE_WRITE_KILL_PRIV -> clear S_ISUID and S_ISGID if executable

So FUSE_WRITE_KILL_PRIV implies the complement of ATTR_KILL_PRIV, which is
somewhat confusing.  Also PRIV implies all privileges, including
"security.capability".

Change the name to FUSE_WRITE_KILL_SUIDGID and make FUSE_WRITE_KILL_PRIV an
alias to perserve API compatibility

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-11-11 17:22:32 +01:00
Vivek Goyal
63f9909ff6 fuse: introduce the notion of FUSE_HANDLE_KILLPRIV_V2
We already have FUSE_HANDLE_KILLPRIV flag that says that file server will
remove suid/sgid/caps on truncate/chown/write. But that's little different
from what Linux VFS implements.

To be consistent with Linux VFS behavior what we want is.

- caps are always cleared on chown/write/truncate
- suid is always cleared on chown, while for truncate/write it is cleared
  only if caller does not have CAP_FSETID.
- sgid is always cleared on chown, while for truncate/write it is cleared
  only if caller does not have CAP_FSETID as well as file has group execute
  permission.

As previous flag did not provide above semantics. Implement a V2 of the
protocol with above said constraints.

Server does not know if caller has CAP_FSETID or not. So for the case
of write()/truncate(), client will send information in special flag to
indicate whether to kill priviliges or not. These changes are in subsequent
patches.

FUSE_HANDLE_KILLPRIV_V2 relies on WRITE being sent to server to clear
suid/sgid/security.capability. But with ->writeback_cache, WRITES are
cached in guest. So it is not recommended to use FUSE_HANDLE_KILLPRIV_V2
and writeback_cache together. Though it probably might be good enough
for lot of use cases.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-11-11 17:22:32 +01:00
Miklos Szeredi
df8629af29 fuse: always revalidate if exclusive create
Failure to do so may result in EEXIST even if the file only exists in the
cache and not in the filesystem.

The atomic nature of O_EXCL mandates that the cached state should be
ignored and existence verified anew.

Reported-by: Ken Schalk <kschalk@nvidia.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-11-11 17:22:32 +01:00
Miklos Szeredi
833c5a42e2 virtiofs: clean up error handling in virtio_fs_get_tree()
Avoid duplicating error cleanup.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-11-11 17:22:32 +01:00
Miklos Szeredi
6a68d1e151 fuse: add fuse_sb_destroy() helper
This is to avoid minor code duplication between fuse_kill_sb_anon() and
fuse_kill_sb_blk().

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-11-11 17:22:32 +01:00
Miklos Szeredi
bd3bf1e85b fuse: simplify get_fuse_conn*()
All callers dereference the result, so no point in checking for NULL
pointer dereference here.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-11-11 17:22:32 +01:00
Miklos Szeredi
514b5e3ff4 fuse: get rid of fuse_mount refcount
Fuse mount now only ever has a refcount of one (before being freed) so the
count field is unnecessary.

Remove the refcounting and fold fuse_mount_put() into callers.  The only
caller of fuse_mount_put() where fm->fc was NULL is fuse_dentry_automount()
and here the fuse_conn_put() can simply be omitted.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-11-11 17:22:32 +01:00
Miklos Szeredi
b19d3d00d6 virtiofs: simplify sb setup
Currently when acquiring an sb for virtiofs fuse_mount_get() is being
called from virtio_fs_set_super() if a new sb is being filled and
fuse_mount_put() is called unconditionally after sget_fc() returns.

The exact same result can be obtained by checking whether
fs_contex->s_fs_info was set to NULL (ref trasferred to sb->s_fs_info) and
only calling fuse_mount_put() if the ref wasn't transferred (error or
matching sb found).

This allows getting rid of virtio_fs_set_super() and fuse_mount_get().

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-11-11 17:22:31 +01:00
Miklos Szeredi
66ab33bf6d virtiofs fix leak in setup
This can be triggered for example by adding the "-omand" mount option,
which will be rejected and virtio_fs_fill_super() will return an error.

In such a case the allocations for fuse_conn and fuse_mount will leak due
to s_root not yet being set and so ->put_super() not being called.

Fixes: a62a8ef9d9 ("virtio-fs: add virtiofs filesystem")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-11-11 17:22:31 +01:00
Miklos Szeredi
3993382bb3 fuse: launder page should wait for page writeback
Qian Cai reports that the WARNING in tree_insert() can be triggered by a
fuzzer with the following call chain:

invalidate_inode_pages2_range()
   fuse_launder_page()
      fuse_writepage_locked()
         tree_insert()

The reason is that another write for the same page is already queued.

The simplest fix is to wait until the pending write is completed and only
after that queue the new write.

Since this case is very rare, the additional wait should not be a problem.

Reported-by: Qian Cai <cai@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-11-11 17:22:31 +01:00
Linus Torvalds
694565356c fuse update for 5.10
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Merge tag 'fuse-update-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse

Pull fuse updates from Miklos Szeredi:

 - Support directly accessing host page cache from virtiofs. This can
   improve I/O performance for various workloads, as well as reducing
   the memory requirement by eliminating double caching. Thanks to Vivek
   Goyal for doing most of the work on this.

 - Allow automatic submounting inside virtiofs. This allows unique
   st_dev/ st_ino values to be assigned inside the guest to files
   residing on different filesystems on the host. Thanks to Max Reitz
   for the patches.

 - Fix an old use after free bug found by Pradeep P V K.

* tag 'fuse-update-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: (25 commits)
  virtiofs: calculate number of scatter-gather elements accurately
  fuse: connection remove fix
  fuse: implement crossmounts
  fuse: Allow fuse_fill_super_common() for submounts
  fuse: split fuse_mount off of fuse_conn
  fuse: drop fuse_conn parameter where possible
  fuse: store fuse_conn in fuse_req
  fuse: add submount support to <uapi/linux/fuse.h>
  fuse: fix page dereference after free
  virtiofs: add logic to free up a memory range
  virtiofs: maintain a list of busy elements
  virtiofs: serialize truncate/punch_hole and dax fault path
  virtiofs: define dax address space operations
  virtiofs: add DAX mmap support
  virtiofs: implement dax read/write operations
  virtiofs: introduce setupmapping/removemapping commands
  virtiofs: implement FUSE_INIT map_alignment field
  virtiofs: keep a list of free dax memory ranges
  virtiofs: add a mount option to enable dax
  virtiofs: set up virtio_fs dax_device
  ...
2020-10-19 14:28:30 -07:00
Vivek Goyal
42d3e2d041 virtiofs: calculate number of scatter-gather elements accurately
virtiofs currently maps various buffers in scatter gather list and it looks
at number of pages (ap->pages) and assumes that same number of pages will
be used both for input and output (sg_count_fuse_req()), and calculates
total number of scatterlist elements accordingly.

But looks like this assumption is not valid in all the cases. For example,
Cai Qian reported that trinity, triggers warning with virtiofs sometimes.
A closer look revealed that if one calls ioctl(fd, 0x5a004000, buf), it
will trigger following warning.

WARN_ON(out_sgs + in_sgs != total_sgs)

In this case, total_sgs = 8, out_sgs=4, in_sgs=3. Number of pages is 2
(ap->pages), but out_sgs are using both the pages but in_sgs are using
only one page. In this case, fuse_do_ioctl() sets different size values
for input and output.

args->in_args[args->in_numargs - 1].size == 6656
args->out_args[args->out_numargs - 1].size == 4096

So current method of calculating how many scatter-gather list elements
will be used is not accurate. Make calculations more precise by parsing
size and ap->descs.

Reported-by: Qian Cai <cai@redhat.com>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Link: https://lore.kernel.org/linux-fsdevel/5ea77e9f6cb8c2db43b09fbd4158ab2d8c066a0a.camel@redhat.com/
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-10-14 14:16:22 +02:00
Linus Torvalds
3ad11d7ac8 block-5.10-2020-10-12
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Merge tag 'block-5.10-2020-10-12' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:

 - Series of merge handling cleanups (Baolin, Christoph)

 - Series of blk-throttle fixes and cleanups (Baolin)

 - Series cleaning up BDI, seperating the block device from the
   backing_dev_info (Christoph)

 - Removal of bdget() as a generic API (Christoph)

 - Removal of blkdev_get() as a generic API (Christoph)

 - Cleanup of is-partition checks (Christoph)

 - Series reworking disk revalidation (Christoph)

 - Series cleaning up bio flags (Christoph)

 - bio crypt fixes (Eric)

 - IO stats inflight tweak (Gabriel)

 - blk-mq tags fixes (Hannes)

 - Buffer invalidation fixes (Jan)

 - Allow soft limits for zone append (Johannes)

 - Shared tag set improvements (John, Kashyap)

 - Allow IOPRIO_CLASS_RT for CAP_SYS_NICE (Khazhismel)

 - DM no-wait support (Mike, Konstantin)

 - Request allocation improvements (Ming)

 - Allow md/dm/bcache to use IO stat helpers (Song)

 - Series improving blk-iocost (Tejun)

 - Various cleanups (Geert, Damien, Danny, Julia, Tetsuo, Tian, Wang,
   Xianting, Yang, Yufen, yangerkun)

* tag 'block-5.10-2020-10-12' of git://git.kernel.dk/linux-block: (191 commits)
  block: fix uapi blkzoned.h comments
  blk-mq: move cancel of hctx->run_work to the front of blk_exit_queue
  blk-mq: get rid of the dead flush handle code path
  block: get rid of unnecessary local variable
  block: fix comment and add lockdep assert
  blk-mq: use helper function to test hw stopped
  block: use helper function to test queue register
  block: remove redundant mq check
  block: invoke blk_mq_exit_sched no matter whether have .exit_sched
  percpu_ref: don't refer to ref->data if it isn't allocated
  block: ratelimit handle_bad_sector() message
  blk-throttle: Re-use the throtl_set_slice_end()
  blk-throttle: Open code __throtl_de/enqueue_tg()
  blk-throttle: Move service tree validation out of the throtl_rb_first()
  blk-throttle: Move the list operation after list validation
  blk-throttle: Fix IO hang for a corner case
  blk-throttle: Avoid tracking latency if low limit is invalid
  blk-throttle: Avoid getting the current time if tg->last_finish_time is 0
  blk-throttle: Remove a meaningless parameter for throtl_downgrade_state()
  block: Remove redundant 'return' statement
  ...
2020-10-13 12:12:44 -07:00
Miklos Szeredi
413daa1a3f fuse: connection remove fix
Re-add lost removal of fc from fuse_conn_list and the control filesystem.

Reported-by: kernel test robot <rong.a.chen@intel.com>
Fixes: fcee216beb ("fuse: split fuse_mount off of fuse_conn")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-10-12 10:28:14 +02:00
Max Reitz
bf109c6404 fuse: implement crossmounts
FUSE servers can indicate crossmount points by setting FUSE_ATTR_SUBMOUNT
in fuse_attr.flags.  The inode will then be marked as S_AUTOMOUNT, and the
.d_automount implementation creates a new submount at that location, so
that the submount gets a distinct st_dev value.

Note that all submounts get a distinct superblock and a distinct st_dev
value, so for virtio-fs, even if the same filesystem is mounted more than
once on the host, none of its mount points will have the same st_dev.  We
need distinct superblocks because the superblock points to the root node,
but the different host mounts may show different trees (e.g. due to
submounts in some of them, but not in others).

Right now, this behavior is only enabled when fuse_conn.auto_submounts is
set, which is the case only for virtio-fs.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-10-09 16:33:47 +02:00
Christoph Hellwig
823423ef55 bdi: invert BDI_CAP_NO_ACCT_WB
Replace BDI_CAP_NO_ACCT_WB with a positive BDI_CAP_WRITEBACK_ACCT to
make the checks more obvious.  Also remove the pointless
bdi_cap_account_writeback wrapper that just obsfucates the check.

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
Christoph Hellwig
55b2598e84 bdi: initialize ->ra_pages and ->io_pages in bdi_init
Set up a readahead size by default, as very few users have a good
reason to change it.  This means code, ecryptfs, and orangefs now
set up the values while they were previously missing it, while ubifs,
mtd and vboxsf manually set it to 0 to avoid readahead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: David Sterba <dsterba@suse.com> [btrfs]
Acked-by: Richard Weinberger <richard@nod.at> [ubifs, mtd]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-24 13:43:39 -06:00
Max Reitz
1866d779d5 fuse: Allow fuse_fill_super_common() for submounts
Submounts have their own superblock, which needs to be initialized.
However, they do not have a fuse_fs_context associated with them, and
the root node's attributes should be taken from the mountpoint's node.

Extend fuse_fill_super_common() to work for submounts by making the @ctx
parameter optional, and by adding a @submount_finode parameter.

(There is a plain "unsigned" in an existing code block that is being
indented by this commit.  Extend it to "unsigned int" so checkpatch does
not complain.)

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-09-18 15:17:41 +02:00
Max Reitz
fcee216beb fuse: split fuse_mount off of fuse_conn
We want to allow submounts for the same fuse_conn, but with different
superblocks so that each of the submounts has its own device ID.  To do
so, we need to split all mount-specific information off of fuse_conn
into a new fuse_mount structure, so that multiple mounts can share a
single fuse_conn.

We need to take care only to perform connection-level actions once (i.e.
when the fuse_conn and thus the first fuse_mount are established, or
when the last fuse_mount and thus the fuse_conn are destroyed).  For
example, fuse_sb_destroy() must invoke fuse_send_destroy() until the
last superblock is released.

To do so, we keep track of which fuse_mount is the root mount and
perform all fuse_conn-level actions only when this fuse_mount is
involved.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-09-18 15:17:41 +02:00
Max Reitz
8f622e9497 fuse: drop fuse_conn parameter where possible
With the last commit, all functions that handle some existing fuse_req
no longer need to be given the associated fuse_conn, because they can
get it from the fuse_req object.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-09-18 15:17:41 +02:00
Max Reitz
24754db272 fuse: store fuse_conn in fuse_req
Every fuse_req belongs to a fuse_conn.  Right now, we always know which
fuse_conn that is based on the respective device, but we want to allow
multiple (sub)mounts per single connection, and then the corresponding
filesystem is not going to be so trivial to obtain.

Storing a pointer to the associated fuse_conn in every fuse_req will
allow us to trivially find any request's superblock (and thus
filesystem) even then.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-09-18 15:17:40 +02:00
Miklos Szeredi
d78092e493 fuse: fix page dereference after free
After unlock_request() pages from the ap->pages[] array may be put (e.g. by
aborting the connection) and the pages can be freed.

Prevent use after free by grabbing a reference to the page before calling
unlock_request().

The original patch was created by Pradeep P V K.

Reported-by: Pradeep P V K <ppvk@codeaurora.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-09-18 10:36:50 +02:00
Al Viro
933a3752ba fuse: fix the ->direct_IO() treatment of iov_iter
the callers rely upon having any iov_iter_truncate() done inside
->direct_IO() countered by iov_iter_reexpand().

Reported-by: Qian Cai <cai@redhat.com>
Tested-by: Qian Cai <cai@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-09-17 17:26:56 -04:00
Vivek Goyal
9a752d18c8 virtiofs: add logic to free up a memory range
Add logic to free up a busy memory range. Freed memory range will be
returned to free pool. Add a worker which can be started to select
and free some busy memory ranges.

Process can also steal one of its busy dax ranges if free range is not
available. I will refer it to as direct reclaim.

If free range is not available and nothing can't be stolen from same
inode, caller waits on a waitq for free range to become available.

For reclaiming a range, as of now we need to hold following locks in
specified order.

	down_write(&fi->i_mmap_sem);
	down_write(&fi->dax->sem);

We look for a free range in following order.

A. Try to get a free range.
B. If not, try direct reclaim.
C. If not, wait for a memory range to become free

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-09-10 11:39:23 +02:00
Vivek Goyal
d0cfb9dcbc virtiofs: maintain a list of busy elements
This list will be used selecting fuse_dax_mapping to free when number of
free mappings drops below a threshold.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-09-10 11:39:23 +02:00
Vivek Goyal
6ae330cad6 virtiofs: serialize truncate/punch_hole and dax fault path
Currently in fuse we don't seem have any lock which can serialize fault
path with truncate/punch_hole path. With dax support I need one for
following reasons.

1. Dax requirement

  DAX fault code relies on inode size being stable for the duration of
  fault and want to serialize with truncate/punch_hole and they explicitly
  mention it.

  static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
                               const struct iomap_ops *ops)
        /*
         * Check whether offset isn't beyond end of file now. Caller is
         * supposed to hold locks serializing us with truncate / punch hole so
         * this is a reliable test.
         */
        max_pgoff = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);

2. Make sure there are no users of pages being truncated/punch_hole

  get_user_pages() might take references to page and then do some DMA
  to said pages. Filesystem might truncate those pages without knowing
  that a DMA is in progress or some I/O is in progress. So use
  dax_layout_busy_page() to make sure there are no such references
  and I/O is not in progress on said pages before moving ahead with
  truncation.

3. Limitation of kvm page fault error reporting

  If we are truncating file on host first and then removing mappings in
  guest lateter (truncate page cache etc), then this could lead to a
  problem with KVM. Say a mapping is in place in guest and truncation
  happens on host. Now if guest accesses that mapping, then host will
  take a fault and kvm will either exit to qemu or spin infinitely.

  IOW, before we do truncation on host, we need to make sure that guest
  inode does not have any mapping in that region or whole file.

4. virtiofs memory range reclaim

 Soon I will introduce the notion of being able to reclaim dax memory
 ranges from a fuse dax inode. There also I need to make sure that
 no I/O or fault is going on in the reclaimed range and nobody is using
 it so that range can be reclaimed without issues.

Currently if we take inode lock, that serializes read/write. But it does
not do anything for faults. So I add another semaphore fuse_inode->i_mmap_sem
for this purpose.  It can be used to serialize with faults.

As of now, I am adding taking this semaphore only in dax fault path and
not regular fault path because existing code does not have one. May
be existing code can benefit from it as well to take care of some
races, but that we can fix later if need be. For now, I am just focussing
only on DAX path which is new path.

Also added logic to take fuse_inode->i_mmap_sem in
truncate/punch_hole/open(O_TRUNC) path to make sure file truncation and
fuse dax fault are mutually exlusive and avoid all the above problems.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-09-10 11:39:23 +02:00
Vivek Goyal
9483e7d580 virtiofs: define dax address space operations
This is done along the lines of ext4 and xfs.  I primarily wanted
->writepages hook at this time so that I could call into
dax_writeback_mapping_range().  This in turn will decide which pfns need to
be written back.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-09-10 11:39:23 +02:00
Stefan Hajnoczi
2a9a609a0c virtiofs: add DAX mmap support
Add DAX mmap() support.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-09-10 11:39:23 +02:00
Vivek Goyal
c2d0ad00d9 virtiofs: implement dax read/write operations
This patch implements basic DAX support. mmap() is not implemented
yet and will come in later patches. This patch looks into implemeting
read/write.

We make use of interval tree to keep track of per inode dax mappings.

Do not use dax for file extending writes, instead just send WRITE message
to daemon (like we do for direct I/O path). This will keep write and
i_size change atomic w.r.t crash.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Signed-off-by: Peng Tao <tao.peng@linux.alibaba.com>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-09-10 11:39:23 +02:00
Stefan Hajnoczi
fd1a1dc6f5 virtiofs: implement FUSE_INIT map_alignment field
The device communicates FUSE_SETUPMAPPING/FUSE_REMOVMAPPING alignment
constraints via the FUST_INIT map_alignment field.  Parse this field and
ensure our DAX mappings meet the alignment constraints.

We don't actually align anything differently since our mappings are
already 2MB aligned.  Just check the value when the connection is
established.  If it becomes necessary to honor arbitrary alignments in
the future we'll have to adjust how mappings are sized.

The upshot of this commit is that we can be confident that mappings will
work even when emulating x86 on Power and similar combinations where the
host page sizes are different.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-09-10 11:39:22 +02:00
Vivek Goyal
45f2348ece virtiofs: keep a list of free dax memory ranges
Divide the dax memory range into fixed size ranges (2MB for now) and put
them in a list. This will track free ranges. Once an inode requires a
free range, we will take one from here and put it in interval-tree
of ranges assigned to inode.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Peng Tao <tao.peng@linux.alibaba.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-09-10 11:39:22 +02:00
Vivek Goyal
1dd539577c virtiofs: add a mount option to enable dax
Add a mount option to allow using dax with virtio_fs.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-09-10 11:39:22 +02:00
Stefan Hajnoczi
22f3787e9d virtiofs: set up virtio_fs dax_device
Setup a dax device.

Use the shm capability to find the cache entry and map it.

The DAX window is accessed by the fs/dax.c infrastructure and must have
struct pages (at least on x86).  Use devm_memremap_pages() to map the
DAX window PCI BAR and allocate struct page.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-09-10 11:39:22 +02:00
Vivek Goyal
f4fd4ae354 virtiofs: get rid of no_mount_options
This option was introduced so that for virtio_fs we don't show any mounts
options fuse_show_options(). Because we don't offer any of these options
to be controlled by mounter.

Very soon we are planning to introduce option "dax" which mounter should
be able to specify. And no_mount_options does not work anymore.


Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-09-10 11:39:22 +02:00
Vivek Goyal
b43b7e81eb virtiofs: provide a helper function for virtqueue initialization
This reduces code duplication and make it little easier to read code.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-09-10 11:39:22 +02:00
André Almeida
c1b0c62715 fuse: update project homepage
As stated in https://sourceforge.net/projects/fuse/, "the FUSE project has
moved to https://github.com/libfuse/" in 22-Dec-2015. Update URLs to
reflect this.

Signed-off-by: André Almeida <andrealmeid@collabora.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-09-04 11:32:10 +02:00
Linus Torvalds
57b0779392 virtio: fixes, features
IRQ bypass support for vdpa and IFC
 MLX5 vdpa driver
 Endian-ness fixes for virtio drivers
 Misc other fixes
 
 Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

Pull virtio updates from Michael Tsirkin:

 - IRQ bypass support for vdpa and IFC

 - MLX5 vdpa driver

 - Endianness fixes for virtio drivers

 - Misc other fixes

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (71 commits)
  vdpa/mlx5: fix up endian-ness for mtu
  vdpa: Fix pointer math bug in vdpasim_get_config()
  vdpa/mlx5: Fix pointer math in mlx5_vdpa_get_config()
  vdpa/mlx5: fix memory allocation failure checks
  vdpa/mlx5: Fix uninitialised variable in core/mr.c
  vdpa_sim: init iommu lock
  virtio_config: fix up warnings on parisc
  vdpa/mlx5: Add VDPA driver for supported mlx5 devices
  vdpa/mlx5: Add shared memory registration code
  vdpa/mlx5: Add support library for mlx5 VDPA implementation
  vdpa/mlx5: Add hardware descriptive header file
  vdpa: Modify get_vq_state() to return error code
  net/vdpa: Use struct for set/get vq state
  vdpa: remove hard coded virtq num
  vdpasim: support batch updating
  vhost-vdpa: support IOTLB batching hints
  vhost-vdpa: support get/set backend features
  vhost: generialize backend features setting/getting
  vhost-vdpa: refine ioctl pre-processing
  vDPA: dont change vq irq after DRIVER_OK
  ...
2020-08-11 14:34:17 -07:00
Michael S. Tsirkin
2c0349ec1a virtio_fs: convert to LE accessors
Virtio fs is modern-only. Use LE accessors for config space.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-08-05 11:08:41 -04:00
Linus Torvalds
99ea1521a0 Remove uninitialized_var() macro for v5.9-rc1
- Clean up non-trivial uses of uninitialized_var()
 - Update documentation and checkpatch for uninitialized_var() removal
 - Treewide removal of uninitialized_var()
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Merge tag 'uninit-macro-v5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull uninitialized_var() macro removal from Kees Cook:
 "This is long overdue, and has hidden too many bugs over the years. The
  series has several "by hand" fixes, and then a trivial treewide
  replacement.

   - Clean up non-trivial uses of uninitialized_var()

   - Update documentation and checkpatch for uninitialized_var() removal

   - Treewide removal of uninitialized_var()"

* tag 'uninit-macro-v5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  compiler: Remove uninitialized_var() macro
  treewide: Remove uninitialized_var() usage
  checkpatch: Remove awareness of uninitialized_var() macro
  mm/debug_vm_pgtable: Remove uninitialized_var() usage
  f2fs: Eliminate usage of uninitialized_var() macro
  media: sur40: Remove uninitialized_var() usage
  KVM: PPC: Book3S PR: Remove uninitialized_var() usage
  clk: spear: Remove uninitialized_var() usage
  clk: st: Remove uninitialized_var() usage
  spi: davinci: Remove uninitialized_var() usage
  ide: Remove uninitialized_var() usage
  rtlwifi: rtl8192cu: Remove uninitialized_var() usage
  b43: Remove uninitialized_var() usage
  drbd: Remove uninitialized_var() usage
  x86/mm/numa: Remove uninitialized_var() usage
  docs: deprecated.rst: Add uninitialized_var()
2020-08-04 13:49:43 -07:00
Kees Cook
3f649ab728 treewide: Remove uninitialized_var() usage
Using uninitialized_var() is dangerous as it papers over real bugs[1]
(or can in the future), and suppresses unrelated compiler warnings
(e.g. "unused variable"). If the compiler thinks it is uninitialized,
either simply initialize the variable or make compiler changes.

In preparation for removing[2] the[3] macro[4], remove all remaining
needless uses with the following script:

git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \
	xargs perl -pi -e \
		's/\buninitialized_var\(([^\)]+)\)/\1/g;
		 s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;'

drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid
pathological white-space.

No outstanding warnings were found building allmodconfig with GCC 9.3.0
for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64,
alpha, and m68k.

[1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/
[2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/
[3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/
[4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/

Reviewed-by: Leon Romanovsky <leonro@mellanox.com> # drivers/infiniband and mlx4/mlx5
Acked-by: Jason Gunthorpe <jgg@mellanox.com> # IB
Acked-by: Kalle Valo <kvalo@codeaurora.org> # wireless drivers
Reviewed-by: Chao Yu <yuchao0@huawei.com> # erofs
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-07-16 12:35:15 -07:00
Chirantan Ekbote
31070f6cce fuse: Fix parameter for FS_IOC_{GET,SET}FLAGS
The ioctl encoding for this parameter is a long but the documentation says
it should be an int and the kernel drivers expect it to be an int.  If the
fuse driver treats this as a long it might end up scribbling over the stack
of a userspace process that only allocated enough space for an int.

This was previously discussed in [1] and a patch for fuse was proposed in
[2].  From what I can tell the patch in [2] was nacked in favor of adding
new, "fixed" ioctls and using those from userspace.  However there is still
no "fixed" version of these ioctls and the fact is that it's sometimes
infeasible to change all userspace to use the new one.

Handling the ioctls specially in the fuse driver seems like the most
pragmatic way for fuse servers to support them without causing crashes in
userspace applications that call them.

[1]: https://lore.kernel.org/linux-fsdevel/20131126200559.GH20559@hall.aurel32.net/T/
[2]: https://sourceforge.net/p/fuse/mailman/message/31771759/

Signed-off-by: Chirantan Ekbote <chirantan@chromium.org>
Fixes: 59efec7b90 ("fuse: implement ioctl support")
Cc: <stable@vger.kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-07-15 14:18:20 +02:00
Vasily Averin
7779b047a5 fuse: don't ignore errors from fuse_writepages_fill()
fuse_writepages() ignores some errors taken from fuse_writepages_fill() I
believe it is a bug: if .writepages is called with WB_SYNC_ALL it should
either guarantee that all data was successfully saved or return error.

Fixes: 26d614df1d ("fuse: Implement writepages callback")
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-07-14 14:45:42 +02:00
Miklos Szeredi
6ddf3af93e fuse: clean up condition for writepage sending
fuse_writepages_fill uses following construction:

if (wpa && ap->num_pages &&
    (A || B || C)) {
        action;
} else if (wpa && D) {
        if (E) {
                the same action;
        }
}

 - ap->num_pages check is always true and can be removed

 - "if" and "else if" calls the same action and can be merged.

Move checking A, B, C, D, E conditions to a helper, add comments.

Original-patch-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-07-14 14:45:41 +02:00
Miklos Szeredi
b330966f79 fuse: reject options on reconfigure via fsconfig(2)
Previous patch changed handling of remount/reconfigure to ignore all
options, including those that are unknown to the fuse kernel fs.  This was
done for backward compatibility, but this likely only affects the old
mount(2) API.

The new fsconfig(2) based reconfiguration could possibly be improved.  This
would make the new API less of a drop in replacement for the old, OTOH this
is a good chance to get rid of some weirdnesses in the old API.

Several other behaviors might make sense:

 1) unknown options are rejected, known options are ignored

 2) unknown options are rejected, known options are rejected if the value
 is changed, allowed otherwise

 3) all options are rejected

Prior to the backward compatibility fix to ignore all options all known
options were accepted (1), even if they change the value of a mount
parameter; fuse_reconfigure() does not look at the config values set by
fuse_parse_param().

To fix that we'd need to verify that the value provided is the same as set
in the initial configuration (2).  The major drawback is that this is much
more complex than just rejecting all attempts at changing options (3);
i.e. all options signify initial configuration values and don't make sense
on reconfigure.

This patch opts for (3) with the rationale that no mount options are
reconfigurable in fuse.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-07-14 14:45:41 +02:00
Miklos Szeredi
e8b20a474c fuse: ignore 'data' argument of mount(..., MS_REMOUNT)
The command

  mount -o remount -o unknownoption /mnt/fuse

succeeds on kernel versions prior to v5.4 and fails on kernel version at or
after.  This is because fuse_parse_param() rejects any unrecognised options
in case of FS_CONTEXT_FOR_RECONFIGURE, just as for FS_CONTEXT_FOR_MOUNT.

This causes a regression in case the fuse filesystem is in fstab, since
remount sends all options found there to the kernel; even ones that are
meant for the initial mount and are consumed by the userspace fuse server.

Fix this by ignoring mount options, just as fuse_remount_fs() did prior to
the conversion to the new API.

Reported-by: Stefan Priebe <s.priebe@profihost.ag>
Fixes: c30da2e981 ("fuse: convert to use the new mount API")
Cc: <stable@vger.kernel.org> # v5.4
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-07-14 14:45:41 +02:00
Miklos Szeredi
0189a2d367 fuse: use ->reconfigure() instead of ->remount_fs()
s_op->remount_fs() is only called from legacy_reconfigure(), which is not
used after being converted to the new API.

Convert to using ->reconfigure().  This restores the previous behavior of
syncing the filesystem and rejecting MS_MANDLOCK on remount.

Fixes: c30da2e981 ("fuse: convert to use the new mount API")
Cc: <stable@vger.kernel.org> # v5.4
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-07-14 14:45:41 +02:00
Miklos Szeredi
c146024ec4 fuse: fix warning in tree_insert() and clean up writepage insertion
fuse_writepages_fill() calls tree_insert() with ap->num_pages = 0 which
triggers the following warning:

 WARNING: CPU: 1 PID: 17211 at fs/fuse/file.c:1728 tree_insert+0xab/0xc0 [fuse]
 RIP: 0010:tree_insert+0xab/0xc0 [fuse]
 Call Trace:
  fuse_writepages_fill+0x5da/0x6a0 [fuse]
  write_cache_pages+0x171/0x470
  fuse_writepages+0x8a/0x100 [fuse]
  do_writepages+0x43/0xe0

Fix up the warning and clean up the code around rb-tree insertion:

 - Rename tree_insert() to fuse_insert_writeback() and make it return the
   conflicting entry in case of failure

 - Re-add tree_insert() as a wrapper around fuse_insert_writeback()

 - Rename fuse_writepage_in_flight() to fuse_writepage_add() and reverse
   the meaning of the return value to mean

    + "true" in case the writepage entry was successfully added

    + "false" in case it was in-fligt queued on an existing writepage
       entry's auxiliary list or the existing writepage entry's temporary
       page updated

   Switch from fuse_find_writeback() + tree_insert() to
   fuse_insert_writeback()

 - Move setting orig_pages to before inserting/updating the entry; this may
   result in the orig_pages value being discarded later in case of an
   in-flight request

 - In case of a new writepage entry use fuse_writepage_add()
   unconditionally, only set data->wpa if the entry was added.

Fixes: 6b2fb79963 ("fuse: optimize writepages search")
Reported-by: kernel test robot <rong.a.chen@intel.com>
Original-path-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-07-14 14:45:41 +02:00
Miklos Szeredi
69a6487ac0 fuse: move rb_erase() before tree_insert()
In fuse_writepage_end() the old writepages entry needs to be removed from
the rbtree before inserting the new one, otherwise tree_insert() would
fail.  This is a very rare codepath and no reproducer exists.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-07-14 14:45:41 +02:00
Linus Torvalds
5b14671be5 fuse update for 5.8
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Merge tag 'fuse-update-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse

Pull fuse updates from Miklos Szeredi:

 - Fix a rare deadlock in virtiofs

 - Fix st_blocks in writeback cache mode

 - Fix wrong checks in splice move causing spurious warnings

 - Fix a race between a GETATTR request and a FUSE_NOTIFY_INVAL_INODE
   notification

 - Use rb-tree instead of linear search for pages currently under
   writeout by userspace

 - Fix copy_file_range() inconsistencies

* tag 'fuse-update-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: copy_file_range should truncate cache
  fuse: fix copy_file_range cache issues
  fuse: optimize writepages search
  fuse: update attr_version counter on fuse_notify_inval_inode()
  fuse: don't check refcount after stealing page
  fuse: fix weird page warning
  fuse: use dump_page
  virtiofs: do not use fuse_fill_super_common() for device installation
  fuse: always allow query of st_dev
  fuse: always flush dirty data on close(2)
  fuse: invalidate inode attr in writeback cache mode
  fuse: Update stale comment in queue_interrupt()
  fuse: BUG_ON correction in fuse_dev_splice_write()
  virtiofs: Add mount option and atime behavior to the doc
  virtiofs: schedule blocking async replies in separate worker
2020-06-09 15:48:24 -07:00
Linus Torvalds
ee01c4d72a Merge branch 'akpm' (patches from Andrew)
Merge more updates from Andrew Morton:
 "More mm/ work, plenty more to come

  Subsystems affected by this patch series: slub, memcg, gup, kasan,
  pagealloc, hugetlb, vmscan, tools, mempolicy, memblock, hugetlbfs,
  thp, mmap, kconfig"

* akpm: (131 commits)
  arm64: mm: use ARCH_HAS_DEBUG_WX instead of arch defined
  x86: mm: use ARCH_HAS_DEBUG_WX instead of arch defined
  riscv: support DEBUG_WX
  mm: add DEBUG_WX support
  drivers/base/memory.c: cache memory blocks in xarray to accelerate lookup
  mm/thp: rename pmd_mknotpresent() as pmd_mkinvalid()
  powerpc/mm: drop platform defined pmd_mknotpresent()
  mm: thp: don't need to drain lru cache when splitting and mlocking THP
  hugetlbfs: get unmapped area below TASK_UNMAPPED_BASE for hugetlbfs
  sparc32: register memory occupied by kernel as memblock.memory
  include/linux/memblock.h: fix minor typo and unclear comment
  mm, mempolicy: fix up gup usage in lookup_node
  tools/vm/page_owner_sort.c: filter out unneeded line
  mm: swap: memcg: fix memcg stats for huge pages
  mm: swap: fix vmstats for huge pages
  mm: vmscan: limit the range of LRU type balancing
  mm: vmscan: reclaim writepage is IO cost
  mm: vmscan: determine anon/file pressure balance at the reclaim root
  mm: balance LRU lists based on relative thrashing
  mm: only count actual rotations as LRU reclaim cost
  ...
2020-06-03 20:24:15 -07:00
Johannes Weiner
6058eaec81 mm: fold and remove lru_cache_add_anon() and lru_cache_add_file()
They're the same function, and for the purpose of all callers they are
equivalent to lru_cache_add().

[akpm@linux-foundation.org: fix it for local_lock changes]
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Rik van Riel <riel@surriel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Link: http://lkml.kernel.org/r/20200520232525.798933-5-hannes@cmpxchg.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-03 20:09:48 -07:00
Linus Torvalds
ae03c53d00 Merge branch 'work.splice' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull splice updates from Al Viro:
 "Christoph's assorted splice cleanups"

* 'work.splice' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs: rename pipe_buf ->steal to ->try_steal
  fs: make the pipe_buf_operations ->confirm operation optional
  fs: make the pipe_buf_operations ->steal operation optional
  trace: remove tracing_pipe_buf_ops
  pipe: merge anon_pipe_buf*_ops
  fs: simplify do_splice_from
  fs: simplify do_splice_to
2020-06-03 15:52:19 -07:00
Linus Torvalds
94709049fb Merge branch 'akpm' (patches from Andrew)
Merge updates from Andrew Morton:
 "A few little subsystems and a start of a lot of MM patches.

  Subsystems affected by this patch series: squashfs, ocfs2, parisc,
  vfs. With mm subsystems: slab-generic, slub, debug, pagecache, gup,
  swap, memcg, pagemap, memory-failure, vmalloc, kasan"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (128 commits)
  kasan: move kasan_report() into report.c
  mm/mm_init.c: report kasan-tag information stored in page->flags
  ubsan: entirely disable alignment checks under UBSAN_TRAP
  kasan: fix clang compilation warning due to stack protector
  x86/mm: remove vmalloc faulting
  mm: remove vmalloc_sync_(un)mappings()
  x86/mm/32: implement arch_sync_kernel_mappings()
  x86/mm/64: implement arch_sync_kernel_mappings()
  mm/ioremap: track which page-table levels were modified
  mm/vmalloc: track which page-table levels were modified
  mm: add functions to track page directory modifications
  s390: use __vmalloc_node in stack_alloc
  powerpc: use __vmalloc_node in alloc_vm_stack
  arm64: use __vmalloc_node in arch_alloc_vmap_stack
  mm: remove vmalloc_user_node_flags
  mm: switch the test_vmalloc module to use __vmalloc_node
  mm: remove __vmalloc_node_flags_caller
  mm: remove both instances of __vmalloc_node_flags
  mm: remove the prot argument to __vmalloc_node
  mm: remove the pgprot argument to __vmalloc
  ...
2020-06-02 12:21:36 -07:00
Matthew Wilcox (Oracle)
76a0294eb1 fuse: convert from readpages to readahead
Implement the new readahead operation in fuse by using __readahead_batch()
to fill the array of pages in fuse_args_pages directly.  This lets us
inline fuse_readpages_fill() into fuse_readahead().

[willy@infradead.org: build fix]
  Link: http://lkml.kernel.org/r/20200415025938.GB5820@bombadil.infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Acked-by: Miklos Szeredi <mszeredi@redhat.com>
Cc: Chao Yu <yuchao0@huawei.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Gao Xiang <gaoxiang25@huawei.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: http://lkml.kernel.org/r/20200414150233.24495-25-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-02 10:59:07 -07:00
Christoph Hellwig
c928f642c2 fs: rename pipe_buf ->steal to ->try_steal
And replace the arcane return value convention with a simple bool
where true means success and false means failure.

[AV: braino fix folded in]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-05-20 12:14:10 -04:00
Miklos Szeredi
9b46418c40 fuse: copy_file_range should truncate cache
After the copy operation completes the cache is not up-to-date.  Truncate
all pages in the interval that has successfully been copied.

Truncating completely copied dirty pages is okay, since the data has been
overwritten anyway.  Truncating partially copied dirty pages is not okay;
add a comment for now.

Fixes: 88bc7d5097 ("fuse: add support for copy_file_range()")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-05-20 11:39:35 +02:00
Miklos Szeredi
2c4656dfd9 fuse: fix copy_file_range cache issues
a) Dirty cache needs to be written back not just in the writeback_cache
case, since the dirty pages may come from memory maps.

b) The fuse_writeback_range() helper takes an inclusive interval, so the
end position needs to be pos+len-1 instead of pos+len.

Fixes: 88bc7d5097 ("fuse: add support for copy_file_range()")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-05-20 11:39:35 +02:00
Maxim Patlasov
6b2fb79963 fuse: optimize writepages search
Re-work fi->writepages, replacing list with rb-tree.  This improves
performance because kernel fuse iterates through fi->writepages for each
writeback page and typical number of entries is about 800 (for 100MB of
fuse writeback).

Before patch:

10240+0 records in
10240+0 records out
10737418240 bytes (11 GB) copied, 41.3473 s, 260 MB/s

 2  1      0 57445400  40416 6323676    0    0    33 374743 8633 19210  1  8 88  3  0

  29.86%  [kernel]               [k] _raw_spin_lock
  26.62%  [fuse]                 [k] fuse_page_is_writeback

After patch:

10240+0 records in
10240+0 records out
10737418240 bytes (11 GB) copied, 21.4954 s, 500 MB/s

 2  9      0 53676040  31744 10265984    0    0    64 854790 10956 48387  1  6 88  6  0

  23.55%  [kernel]             [k] copy_user_enhanced_fast_string
   9.87%  [kernel]             [k] __memcpy
   3.10%  [kernel]             [k] _raw_spin_lock

Signed-off-by: Maxim Patlasov <mpatlasov@virtuozzo.com>
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-05-19 14:50:38 +02:00
Miklos Szeredi
5ddd9ced9a fuse: update attr_version counter on fuse_notify_inval_inode()
A GETATTR request can race with FUSE_NOTIFY_INVAL_INODE, resulting in the
attribute cache being updated with stale information after the
invalidation.

Fix this by bumping the attribute version in fuse_reverse_inval_inode().

Reported-by: Krzysztof Rusek <rusek@9livesdata.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-05-19 14:50:38 +02:00
Miklos Szeredi
32f98877c5 fuse: don't check refcount after stealing page
page_count() is unstable.  Unless there has been an RCU grace period
between when the page was removed from the page cache and now, a
speculative reference may exist from the page cache.

Reported-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-05-19 14:50:37 +02:00
Miklos Szeredi
a5005c3cda fuse: fix weird page warning
When PageWaiters was added, updating this check was missed.

Reported-by: Nikolaus Rath <Nikolaus@rath.org>
Reported-by: Hugh Dickins <hughd@google.com>
Fixes: 6290602709 ("mm: add PageWaiters indicating tasks are waiting for a page bit")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-05-19 14:50:37 +02:00
Miklos Szeredi
0058938617 fuse: use dump_page
Instead of custom page dumping, use the standard helper.

Reported-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-05-19 14:50:37 +02:00
Vivek Goyal
7fd3abfa8d virtiofs: do not use fuse_fill_super_common() for device installation
fuse_fill_super_common() allocates and installs one fuse_device.  Hence
virtiofs allocates and install all fuse devices by itself except one.

This makes logic little twisted.  There does not seem to be any real need
that why virtiofs can't allocate and install all fuse devices itself.

So opt out of fuse device allocation and installation while calling
fuse_fill_super_common().

Regular fuse still wants fuse_fill_super_common() to install fuse_device.
It needs to prevent against races where two mounters are trying to mount
fuse using same fd.  In that case one will succeed while other will get
-EINVAL.

virtiofs does not have this issue because sget_fc() resolves the race
w.r.t multiple mounters and only one instance of virtio_fs_fill_super()
should be in progress for same filesystem.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-05-19 14:50:37 +02:00
Miklos Szeredi
5157da2ca4 fuse: always allow query of st_dev
Fuse mounts without "allow_other" are off-limits to all non-owners.  Yet it
makes sense to allow querying st_dev on the root, since this value is
provided by the kernel, not the userspace filesystem.

Allow statx(2) with a zero request mask to succeed on a fuse mounts for all
users.

Reported-by: Nikolaus Rath <Nikolaus@rath.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-05-19 14:50:37 +02:00
Miklos Szeredi
614c026e8a fuse: always flush dirty data on close(2)
We want cached data to synced with the userspace filesystem on close(), for
example to allow getting correct st_blocks value.  Do this regardless of
whether the userspace filesystem implements a FLUSH method or not.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-05-19 14:50:37 +02:00
Eryu Guan
cf576c58b3 fuse: invalidate inode attr in writeback cache mode
Under writeback mode, inode->i_blocks is not updated, making utils du
read st.blocks as 0.

For example, when using virtiofs (cache=always & nondax mode) with
writeback_cache enabled, writing a new file and check its disk usage
with du, du reports 0 usage.

  # uname -r
  5.6.0-rc6+
  # mount -t virtiofs virtiofs /mnt/virtiofs
  # rm -f /mnt/virtiofs/testfile

  # create new file and do extend write
  # xfs_io -fc "pwrite 0 4k" /mnt/virtiofs/testfile
  wrote 4096/4096 bytes at offset 0
  4 KiB, 1 ops; 0.0001 sec (28.103 MiB/sec and 7194.2446 ops/sec)
  # du -k /mnt/virtiofs/testfile
  0               <==== disk usage is 0
  # stat -c %s,%b /mnt/virtiofs/testfile
  4096,0          <==== i_size is correct, but st_blocks is 0

Fix it by invalidating attr in fuse_flush(), so we get up-to-date attr
from server on next getattr.

Signed-off-by: Eryu Guan <eguan@linux.alibaba.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-05-19 14:50:37 +02:00
Mauro Carvalho Chehab
72ef5e52b3 docs: fix broken references to text files
Several references got broken due to txt to ReST conversion.

Several of them can be automatically fixed with:

	scripts/documentation-file-ref-check --fix

Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> # hwtracing/coresight/Kconfig
Reviewed-by: Paul E. McKenney <paulmck@kernel.org> # memory-barrier.txt
Acked-by: Alex Shi <alex.shi@linux.alibaba.com> # translations/zh_CN
Acked-by: Federico Vaga <federico.vaga@vaga.pv.it> # translations/it_IT
Acked-by: Marc Zyngier <maz@kernel.org> # kvm/arm64
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/6f919ddb83a33b5f2a63b6b5f0575737bb2b36aa.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-04-20 15:35:59 -06:00
Kirill Tkhai
75d892588e fuse: Update stale comment in queue_interrupt()
Fixes: 04ec5af077 "fuse: export fuse_end_request()"
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-04-20 17:01:34 +02:00
Vasily Averin
0e9fb6f17a fuse: BUG_ON correction in fuse_dev_splice_write()
commit 9635453572 ("fuse: reduce allocation size for splice_write")
changed size of bufs array, so BUG_ON which checks the index of the array
shold also be fixed.

[SzM: turn BUG_ON into WARN_ON]

Fixes: 9635453572 ("fuse: reduce allocation size for splice_write")
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-04-20 17:01:34 +02:00
Vivek Goyal
bb737bbe48 virtiofs: schedule blocking async replies in separate worker
In virtiofs (unlike in regular fuse) processing of async replies is
serialized.  This can result in a deadlock in rare corner cases when
there's a circular dependency between the completion of two or more async
replies.

Such a deadlock can be reproduced with xfstests:generic/503 if TEST_DIR ==
SCRATCH_MNT (which is a misconfiguration):

 - Process A is waiting for page lock in worker thread context and blocked
   (virtio_fs_requests_done_work()).
 - Process B is holding page lock and waiting for pending writes to
   finish (fuse_wait_on_page_writeback()).
 - Write requests are waiting in virtqueue and can't complete because
   worker thread is blocked on page lock (process A).

Fix this by creating a unique work_struct for each async reply that can
block (O_DIRECT read).

Fixes: a62a8ef9d9 ("virtio-fs: add virtiofs filesystem")
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-04-20 17:01:34 +02:00
Miklos Szeredi
3e8cb8b2ea fuse: fix stack use after return
Normal, synchronous requests will have their args allocated on the stack.
After the FR_FINISHED bit is set by receiving the reply from the userspace
fuse server, the originating task may return and reuse the stack frame,
resulting in an Oops if the args structure is dereferenced.

Fix by setting a flag in the request itself upon initializing, indicating
whether it has an asynchronous ->end() callback.

Reported-by: Kyle Sanderson <kyle.leet@gmail.com>
Reported-by: Michael Stapelberg <michael+lkml@stapelberg.ch>
Fixes: 2b319d1f6f ("fuse: don't dereference req->args on finished request")
Cc: <stable@vger.kernel.org> # v5.4
Tested-by: Michael Stapelberg <michael+lkml@stapelberg.ch>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-02-13 09:16:07 +01:00
Linus Torvalds
c9d35ee049 Merge branch 'merge.nfs-fs_parse.1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs file system parameter updates from Al Viro:
 "Saner fs_parser.c guts and data structures. The system-wide registry
  of syntax types (string/enum/int32/oct32/.../etc.) is gone and so is
  the horror switch() in fs_parse() that would have to grow another case
  every time something got added to that system-wide registry.

  New syntax types can be added by filesystems easily now, and their
  namespace is that of functions - not of system-wide enum members. IOW,
  they can be shared or kept private and if some turn out to be widely
  useful, we can make them common library helpers, etc., without having
  to do anything whatsoever to fs_parse() itself.

  And we already get that kind of requests - the thing that finally
  pushed me into doing that was "oh, and let's add one for timeouts -
  things like 15s or 2h". If some filesystem really wants that, let them
  do it. Without somebody having to play gatekeeper for the variants
  blessed by direct support in fs_parse(), TYVM.

  Quite a bit of boilerplate is gone. And IMO the data structures make a
  lot more sense now. -200LoC, while we are at it"

* 'merge.nfs-fs_parse.1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (25 commits)
  tmpfs: switch to use of invalfc()
  cgroup1: switch to use of errorfc() et.al.
  procfs: switch to use of invalfc()
  hugetlbfs: switch to use of invalfc()
  cramfs: switch to use of errofc() et.al.
  gfs2: switch to use of errorfc() et.al.
  fuse: switch to use errorfc() et.al.
  ceph: use errorfc() and friends instead of spelling the prefix out
  prefix-handling analogues of errorf() and friends
  turn fs_param_is_... into functions
  fs_parse: handle optional arguments sanely
  fs_parse: fold fs_parameter_desc/fs_parameter_spec
  fs_parser: remove fs_parameter_description name field
  add prefix to fs_context->log
  ceph_parse_param(), ceph_parse_mon_ips(): switch to passing fc_log
  new primitive: __fs_parse()
  switch rbd and libceph to p_log-based primitives
  struct p_log, variants of warnf() et.al. taking that one instead
  teach logfc() to handle prefices, give it saner calling conventions
  get rid of cg_invalf()
  ...
2020-02-08 13:26:41 -08:00
Al Viro
2e28c49ea6 fuse: switch to use errorfc() et.al.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-02-07 14:48:40 -05:00
Al Viro
d7167b1499 fs_parse: fold fs_parameter_desc/fs_parameter_spec
The former contains nothing but a pointer to an array of the latter...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-02-07 14:48:37 -05:00
Eric Sandeen
96cafb9ccb fs_parser: remove fs_parameter_description name field
Unused now.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-02-07 14:48:36 -05:00
zhengbin
cabdb4fa2f fuse: use true,false for bool variable
Fixes coccicheck warning:

fs/fuse/readdir.c:335:1-19: WARNING: Assignment of 0/1 to bool variable
fs/fuse/file.c:1398:2-19: WARNING: Assignment of 0/1 to bool variable
fs/fuse/file.c:1400:2-20: WARNING: Assignment of 0/1 to bool variable
fs/fuse/cuse.c:454:1-20: WARNING: Assignment of 0/1 to bool variable
fs/fuse/cuse.c:455:1-19: WARNING: Assignment of 0/1 to bool variable
fs/fuse/inode.c:497:2-17: WARNING: Assignment of 0/1 to bool variable
fs/fuse/inode.c:504:2-23: WARNING: Assignment of 0/1 to bool variable
fs/fuse/inode.c:511:2-22: WARNING: Assignment of 0/1 to bool variable
fs/fuse/inode.c:518:2-23: WARNING: Assignment of 0/1 to bool variable
fs/fuse/inode.c:522:2-26: WARNING: Assignment of 0/1 to bool variable
fs/fuse/inode.c:526:2-18: WARNING: Assignment of 0/1 to bool variable
fs/fuse/inode.c:1000:1-20: WARNING: Assignment of 0/1 to bool variable

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-02-06 16:39:28 +01:00
Vivek Goyal
519525fa47 fuse: Support RENAME_WHITEOUT flag
Allow fuse to pass RENAME_WHITEOUT to fuse server.  Overlayfs on top of
virtiofs uses RENAME_WHITEOUT.

Without this patch renaming a directory in overlayfs (dir is on lower)
fails with -EINVAL. With this patch it works.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-02-06 16:39:28 +01:00
Miklos Szeredi
2f1398291b fuse: don't overflow LLONG_MAX with end offset
Handle the special case of fuse_readpages() wanting to read the last page
of a hugest file possible and overflowing the end offset in the process.

This is basically to unbreak xfstests:generic/525 and prevent filesystems
from doing bad things with an overflowing offset.

Reported-by: Xiao Yang <ice_yangxiao@163.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-02-06 16:39:28 +01:00
Miklos Szeredi
f658adeea4 fix up iter on short count in fuse_direct_io()
fuse_direct_io() can end up advancing the iterator by more than the amount
of data read or written.  This case is handled by the generic code if going
through ->direct_IO(), but not in the FOPEN_DIRECT_IO case.

Fix by reverting the extra bytes from the iterator in case of error or a
short count.

To test: install lxcfs, then the following testcase
  int fd = open("/var/lib/lxcfs/proc/uptime", O_RDONLY);
  sendfile(1, fd, NULL, 16777216);
  sendfile(1, fd, NULL, 16777216);
will spew WARN_ON() in iov_iter_pipe().

Reported-by: Peter Geis <pgwipeout@gmail.com>
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Fixes: 3c3db095b6 ("fuse: use iov_iter based generic splice helpers")
Cc: <stable@vger.kernel.org> # v5.1
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-02-06 16:39:28 +01:00
Miklos Szeredi
7df1e988c7 fuse: fix fuse_send_readpages() in the syncronous read case
Buffered read in fuse normally goes via:

 -> generic_file_buffered_read()
   -> fuse_readpages()
     -> fuse_send_readpages()
       ->fuse_simple_request() [called since v5.4]

In the case of a read request, fuse_simple_request() will return a
non-negative bytecount on success or a negative error value.  A positive
bytecount was taken to be an error and the PG_error flag set on the page.
This resulted in generic_file_buffered_read() falling back to ->readpage(),
which would repeat the read request and succeed.  Because of the repeated
read succeeding the bug was not detected with regression tests or other use
cases.

The FTP module in GVFS however fails the second read due to the
non-seekable nature of FTP downloads.

Fix by checking and ignoring positive return value from
fuse_simple_request().

Reported-by: Ondrej Holy <oholy@redhat.com>
Link: https://gitlab.gnome.org/GNOME/gvfs/issues/441
Fixes: 134831e36b ("fuse: convert readpages to simple api")
Cc: <stable@vger.kernel.org> # v5.4
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-01-16 11:09:36 +01:00
David Howells
76f6777c9c pipe: Fix iteration end check in fuse_dev_splice_write()
Fix the iteration end check in fuse_dev_splice_write().  The iterator
position can only be compared with == or != since wrappage may be involved.

Fixes: 8cefc107ca ("pipe: Use head and tail pointers for the ring, not cursor and length")
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-06 13:57:04 -08:00
Linus Torvalds
7ce4fab819 fuse update for 5.5
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Merge tag 'fuse-update-5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse

Pull fuse update from Miklos Szeredi:

 - Fix a regression introduced in the last release

 - Fix a number of issues with validating data coming from userspace

 - Some cleanups in virtiofs

* tag 'fuse-update-5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: fix Kconfig indentation
  fuse: fix leak of fuse_io_priv
  virtiofs: Use completions while waiting for queue to be drained
  virtiofs: Do not send forget request "struct list_head" element
  virtiofs: Use a common function to send forget
  virtiofs: Fix old-style declaration
  fuse: verify nlink
  fuse: verify write return
  fuse: verify attributes
2019-12-05 12:44:22 -08:00
Linus Torvalds
0da522107e compat_ioctl: remove most of fs/compat_ioctl.c
As part of the cleanup of some remaining y2038 issues, I came to
 fs/compat_ioctl.c, which still has a couple of commands that need support
 for time64_t.
 
 In completely unrelated work, I spent time on cleaning up parts of this
 file in the past, moving things out into drivers instead.
 
 After Al Viro reviewed an earlier version of this series and did a lot
 more of that cleanup, I decided to try to completely eliminate the rest
 of it and move it all into drivers.
 
 This series incorporates some of Al's work and many patches of my own,
 but in the end stops short of actually removing the last part, which is
 the scsi ioctl handlers. I have patches for those as well, but they need
 more testing or possibly a rewrite.
 
 Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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Merge tag 'compat-ioctl-5.5' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground

Pull removal of most of fs/compat_ioctl.c from Arnd Bergmann:
 "As part of the cleanup of some remaining y2038 issues, I came to
  fs/compat_ioctl.c, which still has a couple of commands that need
  support for time64_t.

  In completely unrelated work, I spent time on cleaning up parts of
  this file in the past, moving things out into drivers instead.

  After Al Viro reviewed an earlier version of this series and did a lot
  more of that cleanup, I decided to try to completely eliminate the
  rest of it and move it all into drivers.

  This series incorporates some of Al's work and many patches of my own,
  but in the end stops short of actually removing the last part, which
  is the scsi ioctl handlers. I have patches for those as well, but they
  need more testing or possibly a rewrite"

* tag 'compat-ioctl-5.5' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground: (42 commits)
  scsi: sd: enable compat ioctls for sed-opal
  pktcdvd: add compat_ioctl handler
  compat_ioctl: move SG_GET_REQUEST_TABLE handling
  compat_ioctl: ppp: move simple commands into ppp_generic.c
  compat_ioctl: handle PPPIOCGIDLE for 64-bit time_t
  compat_ioctl: move PPPIOCSCOMPRESS to ppp_generic
  compat_ioctl: unify copy-in of ppp filters
  tty: handle compat PPP ioctls
  compat_ioctl: move SIOCOUTQ out of compat_ioctl.c
  compat_ioctl: handle SIOCOUTQNSD
  af_unix: add compat_ioctl support
  compat_ioctl: reimplement SG_IO handling
  compat_ioctl: move WDIOC handling into wdt drivers
  fs: compat_ioctl: move FITRIM emulation into file systems
  gfs2: add compat_ioctl support
  compat_ioctl: remove unused convert_in_user macro
  compat_ioctl: remove last RAID handling code
  compat_ioctl: remove /dev/raw ioctl translation
  compat_ioctl: remove PCI ioctl translation
  compat_ioctl: remove joystick ioctl translation
  ...
2019-12-01 13:46:15 -08:00
Linus Torvalds
6a965666b7 Pipework for general notification queue
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Merge tag 'notifications-pipe-prep-20191115' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

Pull pipe rework from David Howells:
 "This is my set of preparatory patches for building a general
  notification queue on top of pipes. It makes a number of significant
  changes:

   - It removes the nr_exclusive argument from __wake_up_sync_key() as
     this is always 1. This prepares for the next step:

   - Adds wake_up_interruptible_sync_poll_locked() so that poll can be
     woken up from a function that's holding the poll waitqueue
     spinlock.

   - Change the pipe buffer ring to be managed in terms of unbounded
     head and tail indices rather than bounded index and length. This
     means that reading the pipe only needs to modify one index, not
     two.

   - A selection of helper functions are provided to query the state of
     the pipe buffer, plus a couple to apply updates to the pipe
     indices.

   - The pipe ring is allowed to have kernel-reserved slots. This allows
     many notification messages to be spliced in by the kernel without
     allowing userspace to pin too many pages if it writes to the same
     pipe.

   - Advance the head and tail indices inside the pipe waitqueue lock
     and use wake_up_interruptible_sync_poll_locked() to poke poll
     without having to take the lock twice.

   - Rearrange pipe_write() to preallocate the buffer it is going to
     write into and then drop the spinlock. This allows kernel
     notifications to then be added the ring whilst it is filling the
     buffer it allocated. The read side is stalled because the pipe
     mutex is still held.

   - Don't wake up readers on a pipe if there was already data in it
     when we added more.

   - Don't wake up writers on a pipe if the ring wasn't full before we
     removed a buffer"

* tag 'notifications-pipe-prep-20191115' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  pipe: Remove sync on wake_ups
  pipe: Increase the writer-wakeup threshold to reduce context-switch count
  pipe: Check for ring full inside of the spinlock in pipe_write()
  pipe: Remove redundant wakeup from pipe_write()
  pipe: Rearrange sequence in pipe_write() to preallocate slot
  pipe: Conditionalise wakeup in pipe_read()
  pipe: Advance tail pointer inside of wait spinlock in pipe_read()
  pipe: Allow pipes to have kernel-reserved slots
  pipe: Use head and tail pointers for the ring, not cursor and length
  Add wake_up_interruptible_sync_poll_locked()
  Remove the nr_exclusive argument from __wake_up_sync_key()
  pipe: Reduce #inclusion of pipe_fs_i.h
2019-11-30 14:12:13 -08:00
Krzysztof Kozlowski
8d66fcb748 fuse: fix Kconfig indentation
Adjust indentation from spaces to tab (+optional two spaces) as in
coding style with command like:
	$ sed -e 's/^        /\t/' -i */Kconfig

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-11-27 09:35:20 +01:00
Miklos Szeredi
f1ebdeffc6 fuse: fix leak of fuse_io_priv
exit_aio() is sometimes stuck in wait_for_completion() after aio is issued
with direct IO and the task receives a signal.

The reason is failure to call ->ki_complete() due to a leaked reference to
fuse_io_priv.  This happens in fuse_async_req_send() if
fuse_simple_background() returns an error (e.g. -EINTR).

In this case the error value is propagated via io->err, so return success
to not confuse callers.

This issue is tracked as a virtio-fs issue:
https://gitlab.com/virtio-fs/qemu/issues/14

Reported-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Fixes: 45ac96ed7c ("fuse: convert direct_io to simple api")
Cc: <stable@vger.kernel.org> # v5.4
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-11-27 09:33:49 +01:00
Vivek Goyal
724c15a43e virtiofs: Use completions while waiting for queue to be drained
While we wait for queue to finish draining, use completions instead of
usleep_range(). This is better way of waiting for event.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-11-22 13:29:50 +01:00