Commit Graph

391 Commits

Author SHA1 Message Date
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
Miklos Szeredi
8aab336b14 fuse: verify write return
Make sure filesystem is not returning a bogus number of bytes written.

Fixes: ea9b9907b8 ("fuse: implement perform_write")
Cc: <stable@vger.kernel.org> # v2.6.26
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-11-12 11:49:04 +01:00
Vasily Averin
091d1a7267 fuse: redundant get_fuse_inode() calls in fuse_writepages_fill()
Currently fuse_writepages_fill() calls get_fuse_inode() few times with
the same argument.

Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-10-23 14:26:37 +02:00
Miklos Szeredi
e4648309b8 fuse: truncate pending writes on O_TRUNC
Make sure cached writes are not reordered around open(..., O_TRUNC), with
the obvious wrong results.

Fixes: 4d99ff8f12 ("fuse: Turn writeback cache on")
Cc: <stable@vger.kernel.org> # v3.15+
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-10-23 14:26:37 +02:00
Khazhismel Kumykov
dc69e98c24 fuse: kmemcg account fs data
account per-file, dentry, and inode data

blockdev/superblock and temporary per-request data was left alone, as
this usually isn't accounted

Reviewed-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Khazhismel Kumykov <khazhy@google.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-24 15:28:01 +02:00
Vasily Averin
d5880c7a86 fuse: fix missing unlock_page in fuse_writepage()
unlock_page() was missing in case of an already in-flight write against the
same page.

Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Fixes: ff17be0864 ("fuse: writepage: skip already in flight")
Cc: <stable@vger.kernel.org> # v3.13
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-24 15:28:01 +02:00
Miklos Szeredi
7213394c4e fuse: simplify request allocation
Page arrays are not allocated together with the request anymore.  Get rid
of the dead code

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-10 16:29:50 +02:00
Miklos Szeredi
4cb548666e fuse: convert release to simple api
Since we cannot reserve the request structure up-front, make sure that the
request allocation doesn't fail using __GFP_NOFAIL.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-10 16:29:50 +02:00
Miklos Szeredi
33826ebbbe fuse: convert writepages to simple api
Derive fuse_writepage_args from fuse_io_args.

Sending the request is tricky since it was done with fi->lock held, hence
we must either use atomic allocation or release the lock.  Both are
possible so try atomic first and if it fails, release the lock and do the
regular allocation with GFP_NOFS and __GFP_NOFAIL.  Both flags are
necessary for correct operation.

Move the page realloc function from dev.c to file.c and convert to using
fuse_writepage_args.

The last caller of fuse_write_fill() is gone, so get rid of it.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-10 16:29:49 +02:00
Miklos Szeredi
43f5098eb8 fuse: convert readdir to simple api
The old fuse_read_fill() helper can be deleted, now that the last user is
gone.

The fuse_io_args struct is moved to fuse_i.h so it can be shared between
readdir/read code.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-10 16:29:49 +02:00
Miklos Szeredi
134831e36b fuse: convert readpages to simple api
Need to extend fuse_io_args with 'attr_ver' and 'ff' members, that take the
functionality of the same named members in fuse_req.

fuse_short_read() can now take struct fuse_args_pages.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-10 16:29:49 +02:00
Miklos Szeredi
45ac96ed7c fuse: convert direct_io to simple api
Change of semantics in fuse_async_req_send/fuse_send_(read|write): these
can now return error, in which case the 'end' callback isn't called, so the
fuse_io_args object needs to be freed.

Added verification that the return value is sane (less than or equal to the
requested read/write size).

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-10 16:29:49 +02:00
Miklos Szeredi
338f2e3f33 fuse: convert sync write to simple api
Extract a fuse_write_flags() helper that converts ki_flags relevant write
to open flags.

The other parts of fuse_send_write() aren't used in the
fuse_perform_write() case.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-10 16:29:49 +02:00
Miklos Szeredi
00793ca5d4 fuse: covert readpage to simple api
Derive fuse_io_args from struct fuse_args_pages.  This will be used for
both synchronous and asynchronous read/write requests.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-10 16:29:49 +02:00
Miklos Szeredi
a0d45d84f4 fuse: fuse_short_read(): don't take fuse_req as argument
This will allow the use of this function when converting to the simple api
(which doesn't use fuse_req).

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-10 16:29:49 +02:00
Miklos Szeredi
093f38a2c1 fuse: convert ioctl to simple api
fuse_simple_request() is converted to return length of last (instead of
single) out arg, since FUSE_IOCTL_OUT has two out args, the second of which
is variable length.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-10 16:29:49 +02:00
Miklos Szeredi
4c4f03f78c fuse: move page alloc
fuse_req_pages_alloc() is moved to file.c, since its internal use by the
device code will eventually be removed.

Rename to fuse_pages_alloc() to signify that it's not only usable for
fuse_req page array.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-10 16:29:49 +02:00
Miklos Szeredi
1ccd1ea249 fuse: convert destroy to simple api
We can use the "force" flag to make sure the DESTROY request is always sent
to userspace.  So no need to keep it allocated during the lifetime of the
filesystem.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-10 16:29:49 +02:00
Miklos Szeredi
c500ebaa90 fuse: convert flush to simple api
Add 'force' to fuse_args and use fuse_get_req_nofail_nopages() to allocate
the request in that case.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-10 16:29:48 +02:00
Miklos Szeredi
40ac7ab2d0 fuse: simplify 'nofail' request
Instead of complex games with a reserved request, just use __GFP_NOFAIL.

Both calers (flush, readdir) guarantee that connection was already
initialized, so no need to wait for fc->initialized.

Also remove unneeded clearing of FR_BACKGROUND flag.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-10 16:29:48 +02:00
Miklos Szeredi
d5b4854357 fuse: flatten 'struct fuse_args'
...to make future expansion simpler.  The hiearachical structure is a
historical thing that does not serve any practical purpose.

The generated code is excatly the same before and after the patch.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-10 16:29:48 +02:00
Maxim Patlasov
17b2cbe294 fuse: cleanup fuse_wait_on_page_writeback
fuse_wait_on_page_writeback() always returns zero and nobody cares.
Let's make it void.

Signed-off-by: Maxim Patlasov <mpatlasov@virtuozzo.com>
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-02 11:07:30 +02:00
Amir Goldstein
fe0da9c09b fuse: copy_file_range needs to strip setuid bits and update timestamps
Like ->write_iter(), we update mtime and strip setuid of dst file before
copy and like ->read_iter(), we update atime of src file after copy.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Acked-by: Miklos Szeredi <miklos@szeredi.hu>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-06-09 10:07:07 -07:00
Amir Goldstein
5dae222a5f vfs: allow copy_file_range to copy across devices
We want to enable cross-filesystem copy_file_range functionality
where possible, so push the "same superblock only" checks down to
the individual filesystem callouts so they can make their own
decisions about cross-superblock copy offload and fallack to
generic_copy_file_range() for cross-superblock copy.

[Amir] We do not call ->remap_file_range() in case the files are not
on the same sb and do not call ->copy_file_range() in case the files
do not belong to the same filesystem driver.

This changes behavior of the copy_file_range(2) syscall, which will
now allow cross filesystem in-kernel copy.  CIFS already supports
cross-superblock copy, between two shares to the same server. This
functionality will now be available via the copy_file_range(2) syscall.

Cc: Steve French <stfrench@microsoft.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-06-09 10:06:20 -07:00
Dave Chinner
64bf5ff58d vfs: no fallback for ->copy_file_range
Now that we have generic_copy_file_range(), remove it as a fallback
case when offloads fail. This puts the responsibility for executing
fallbacks on the filesystems that implement ->copy_file_range and
allows us to add operational validity checks to
generic_copy_file_range().

Rework vfs_copy_file_range() to call a new do_copy_file_range()
helper to execute the copying callout, and move calls to
generic_file_copy_range() into filesystem methods where they
currently return failures.

[Amir] overlayfs is not responsible of executing the fallback.
It is the responsibility of the underlying filesystem.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-06-09 10:06:19 -07:00
Miklos Szeredi
26eb3bae50 fuse: extract helper for range writeback
The fuse_writeback_range() helper flushes dirty data to the userspace
filesystem.

When the function returns, the WRITE requests for the data in the given
range have all been completed.  This is not equivalent to fsync() on the
given range, since the userspace filesystem may not yet have the data on
stable storage.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-05-28 13:22:50 +02:00
Miklos Szeredi
a2bc923629 fuse: fix copy_file_range() in the writeback case
Prior to sending COPY_FILE_RANGE to userspace filesystem, we must flush all
dirty pages in both the source and destination files.

This patch adds the missing flush of the source file.

Tested on libfuse-3.5.0 with:

  libfuse/example/passthrough_ll /mnt/fuse/ -o writeback
  libfuse/test/test_syscalls /mnt/fuse/tmp/test

Fixes: 88bc7d5097 ("fuse: add support for copy_file_range()")
Cc: <stable@vger.kernel.org> # v4.20
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-05-28 13:22:50 +02:00
Miklos Szeredi
4a2abf99f9 fuse: add FUSE_WRITE_KILL_PRIV
In the FOPEN_DIRECT_IO case the write path doesn't call file_remove_privs()
and that means setuid bit is not cleared if unpriviliged user writes to a
file with setuid bit set.

pjdfstest chmod test 12.t tests this and fails.

Fix this by adding a flag to the FUSE_WRITE message that requests clearing
privileges on the given file.  This needs 

This better than just calling fuse_remove_privs(), because the attributes
may not be up to date, so in that case a write may miss clearing the
privileges.

Test case:

  $ passthrough_ll /mnt/pasthrough-mnt -o default_permissions,allow_other,cache=never
  $ mkdir /mnt/pasthrough-mnt/testdir
  $ cd /mnt/pasthrough-mnt/testdir
  $ prove -rv pjdfstests/tests/chmod/12.t

Reported-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Tested-by: Vivek Goyal <vgoyal@redhat.com>
2019-05-27 11:42:36 +02:00
Miklos Szeredi
35d6fcbb7c fuse: fallocate: fix return with locked inode
Do the proper cleanup in case the size check fails.

Tested with xfstests:generic/228

Reported-by: kbuild test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: 0cbade024b ("fuse: honor RLIMIT_FSIZE in fuse_file_fallocate")
Cc: Liu Bo <bo.liu@linux.alibaba.com>
Cc: <stable@vger.kernel.org> # v3.5
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-05-27 11:42:35 +02:00
Ian Abbott
6407f44aaf fuse: Add ioctl flag for x32 compat ioctl
Currently, a CUSE server running on a 64-bit kernel can tell when an ioctl
request comes from a process running a 32-bit ABI, but cannot tell whether
the requesting process is using legacy IA32 emulation or x32 ABI.  In
particular, the server does not know the size of the client process's
`time_t` type.

For 64-bit kernels, the `FUSE_IOCTL_COMPAT` and `FUSE_IOCTL_32BIT` flags
are currently set in the ioctl input request (`struct fuse_ioctl_in` member
`flags`) for a 32-bit requesting process.  This patch defines a new flag
`FUSE_IOCTL_COMPAT_X32` and sets it if the 32-bit requesting process is
using the x32 ABI.  This allows the server process to distinguish between
requests coming from client processes using IA32 emulation or the x32 ABI
and so infer the size of the client process's `time_t` type and any other
IA32/x32 differences.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-04-24 17:05:07 +02:00
Alan Somers
154603fe3e fuse: document fuse_fsync_in.fsync_flags
The FUSE_FSYNC_DATASYNC flag was introduced by commit b6aeadeda2
("[PATCH] FUSE - file operations") as a magic number.  No new values have
been added to fsync_flags since.

Signed-off-by: Alan Somers <asomers@FreeBSD.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-04-24 17:05:07 +02:00
Kirill Smelkov
bbd84f3365 fuse: Add FOPEN_STREAM to use stream_open()
Starting from commit 9c225f2655 ("vfs: atomic f_pos accesses as per
POSIX") files opened even via nonseekable_open gate read and write via lock
and do not allow them to be run simultaneously. This can create read vs
write deadlock if a filesystem is trying to implement a socket-like file
which is intended to be simultaneously used for both read and write from
filesystem client.  See commit 10dce8af34 ("fs: stream_open - opener for
stream-like files so that read and write can run simultaneously without
deadlock") for details and e.g. commit 581d21a2d0 ("xenbus: fix deadlock
on writes to /proc/xen/xenbus") for a similar deadlock example on
/proc/xen/xenbus.

To avoid such deadlock it was tempting to adjust fuse_finish_open to use
stream_open instead of nonseekable_open on just FOPEN_NONSEEKABLE flags,
but grepping through Debian codesearch shows users of FOPEN_NONSEEKABLE,
and in particular GVFS which actually uses offset in its read and write
handlers

	https://codesearch.debian.net/search?q=-%3Enonseekable+%3D
	https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1080
	https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1247-1346
	https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1399-1481

so if we would do such a change it will break a real user.

Add another flag (FOPEN_STREAM) for filesystem servers to indicate that the
opened handler is having stream-like semantics; does not use file position
and thus the kernel is free to issue simultaneous read and write request on
opened file handle.

This patch together with stream_open() should be added to stable kernels
starting from v3.14+. This will allow to patch OSSPD and other FUSE
filesystems that provide stream-like files to return FOPEN_STREAM |
FOPEN_NONSEEKABLE in open handler and this way avoid the deadlock on all
kernel versions. This should work because fuse_finish_open ignores unknown
open flags returned from a filesystem and so passing FOPEN_STREAM to a
kernel that is not aware of this flag cannot hurt. In turn the kernel that
is not aware of FOPEN_STREAM will be < v3.14 where just FOPEN_NONSEEKABLE
is sufficient to implement streams without read vs write deadlock.

Cc: stable@vger.kernel.org # v3.14+
Signed-off-by: Kirill Smelkov <kirr@nexedi.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-04-24 17:05:07 +02:00
Liu Bo
0cbade024b fuse: honor RLIMIT_FSIZE in fuse_file_fallocate
fstests generic/228 reported this failure that fuse fallocate does not
honor what 'ulimit -f' has set.

This adds the necessary inode_newsize_ok() check.

Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Fixes: 05ba1f0823 ("fuse: add FALLOCATE operation")
Cc: <stable@vger.kernel.org> # v3.5
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-04-24 17:05:06 +02:00
Miklos Szeredi
9de5be06d0 fuse: fix writepages on 32bit
Writepage requests were cropped to i_size & 0xffffffff, which meant that
mmaped writes to any file larger than 4G might be silently discarded.

Fix by storing the file size in a properly sized variable (loff_t instead
of size_t).

Reported-by: Antonio SJ Musumeci <trapexit@spawn.link>
Fixes: 6eaf4782eb ("fuse: writepages: crop secondary requests")
Cc: <stable@vger.kernel.org> # v3.13
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-04-24 17:05:06 +02:00
Chad Austin
fabf7e0262 fuse: cache readdir calls if filesystem opts out of opendir
If a filesystem returns ENOSYS from opendir and thus opts out of
opendir and releasedir requests, it almost certainly would also like
readdir results cached. Default open_flags to FOPEN_KEEP_CACHE and
FOPEN_CACHE_DIR in that case.

With this patch, I've measured recursive directory enumeration across
large FUSE mounts to be faster than native mounts.

Signed-off-by: Chad Austin <chadaustin@fb.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-02-13 13:15:15 +01:00
Chad Austin
d9a9ea94f7 fuse: support clients that don't implement 'opendir'
Allow filesystems to return ENOSYS from opendir, preventing the kernel from
sending opendir and releasedir messages in the future. This avoids
userspace transitions when filesystems don't need to keep track of state
per directory handle.

A new capability flag, FUSE_NO_OPENDIR_SUPPORT, parallels
FUSE_NO_OPEN_SUPPORT, indicating the new semantics for returning ENOSYS
from opendir.

Signed-off-by: Chad Austin <chadaustin@fb.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-02-13 13:15:15 +01:00
Miklos Szeredi
2f7b6f5bed fuse: lift bad inode checks into callers
Bad inode checks were done  done in various places, and move them into
fuse_file_{read|write}_iter().

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-02-13 13:15:15 +01:00
Miklos Szeredi
55752a3aba fuse: multiplex cached/direct_io file operations
This is cleanup, as well as allowing switching between I/O modes while the
file is open in the future.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-02-13 13:15:15 +01:00
Miklos Szeredi
d4136d6075 fuse add copy_file_range to direct io fops
Nothing preventing copy_file_range to work on files opened with
FOPEN_DIRECT_IO.

Fixes: 88bc7d5097 ("fuse: add support for copy_file_range()")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-02-13 13:15:14 +01:00
Miklos Szeredi
3c3db095b6 fuse: use iov_iter based generic splice helpers
The default splice implementation is grossly inefficient and the iter based
ones work just fine, so use those instead.  I've measured an 8x speedup for
splice write (with len = 128k).

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-02-13 13:15:14 +01:00
Martin Raiber
23c94e1cdc fuse: Switch to using async direct IO for FOPEN_DIRECT_IO
Switch to using the async directo IO code path in fuse_direct_read_iter()
and fuse_direct_write_iter().  This is especially important in connection
with loop devices with direct IO enabled as loop assumes async direct io is
actually async.

Signed-off-by: Martin Raiber <martin@urbackup.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-02-13 13:15:14 +01:00
Miklos Szeredi
75126f5504 fuse: use atomic64_t for khctr
...to get rid of one more fc->lock use.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-02-13 13:15:14 +01:00
Kirill Tkhai
f15ecfef05 fuse: Introduce fi->lock to protect write related fields
To minimize contention of fc->lock, this patch introduces a new spinlock
for protection fuse_inode metadata:

fuse_inode:
	writectr
	writepages
	write_files
	queued_writes
	attr_version

inode:
	i_size
	i_nlink
	i_mtime
	i_ctime

Also, it protects the fields changed in fuse_change_attributes_common()
(too many to list).

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-02-13 13:15:14 +01:00
Kirill Tkhai
4510d86fbb fuse: Convert fc->attr_version into atomic64_t
This patch makes fc->attr_version of atomic64_t type, so fc->lock won't be
needed to read or modify it anymore.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-02-13 13:15:13 +01:00
Kirill Tkhai
ebf84d0c72 fuse: Add fuse_inode argument to fuse_prepare_release()
Here is preparation for next patches, which introduce new fi->lock for
protection of ff->write_entry linked into fi->write_files.

This patch just passes new argument to the function.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-02-13 13:15:13 +01:00
Kirill Tkhai
c5de16cca2 fuse: Replace page without copying in fuse_writepage_in_flight()
It looks like we can optimize page replacement and avoid copying by simple
updating the request's page.

[SzM: swap with new request's tmp page to avoid use after free.]

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-02-13 13:15:12 +01:00
Miklos Szeredi
e2653bd53a fuse: fix leaked aux requests
Auxiliary requests chained on req->misc.write.next may be leaked on
truncate.  Free these as well if the parent request was truncated off.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-02-13 13:15:12 +01:00
Miklos Szeredi
419234d595 fuse: only reuse auxiliary request in fuse_writepage_in_flight()
Don't reuse the queued request, even if it only contains a single page.
This is needed because previous locking changes (spliting out
fiq->waitq.lock from fc->lock) broke the assumption that request will
remain in FR_PENDING at least until the new page contents are copied.

This fix removes a slight optimization for a rare corner case, so we really
shoudln't care.

Reported-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Fixes: fd22d62ed0 ("fuse: no fc->lock for iqueue parts")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-02-13 13:15:12 +01:00
Miklos Szeredi
7f305ca192 fuse: clean up fuse_writepage_in_flight()
Restructure the function to better separate the locked and the unlocked
parts.  Use the "old_req" local variable to mean only the queued request,
and not any auxiliary requests added onto its misc.write.next list.  These
changes are in preparation for the following patch.

Also turn BUG_ON instances into WARN_ON and add a header comment explaining
what the function does.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-02-13 13:15:12 +01:00
Miklos Szeredi
2fe93bd432 fuse: extract fuse_find_writeback() helper
Call this from fuse_range_is_writeback() and fuse_writepage_in_flight().

Turn a BUG_ON() into a WARN_ON() in the process.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-02-13 13:15:12 +01:00