Commit Graph

60814 Commits

Author SHA1 Message Date
Tetsuo Handa
73601ea5b7 fs/open.c: allow opening only regular files during execve()
syzbot is hitting lockdep warning [1] due to trying to open a fifo
during an execve() operation.  But we don't need to open non regular
files during an execve() operation, for all files which we will need are
the executable file itself and the interpreter programs like /bin/sh and
ld-linux.so.2 .

Since the manpage for execve(2) says that execve() returns EACCES when
the file or a script interpreter is not a regular file, and the manpage
for uselib(2) says that uselib() can return EACCES, and we use
FMODE_EXEC when opening for execve()/uselib(), we can bail out if a non
regular file is requested with FMODE_EXEC set.

Since this deadlock followed by khungtaskd warnings is trivially
reproducible by a local unprivileged user, and syzbot's frequent crash
due to this deadlock defers finding other bugs, let's workaround this
deadlock until we get a chance to find a better solution.

[1] https://syzkaller.appspot.com/bug?id=b5095bfec44ec84213bac54742a82483aad578ce

Link: http://lkml.kernel.org/r/1552044017-7890-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp
Reported-by: syzbot <syzbot+e93a80c1bb7c5c56e522461c149f8bf55eab1b2b@syzkaller.appspotmail.com>
Fixes: 8924feff66 ("splice: lift pipe_lock out of splice_to_pipe()")
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Biggers <ebiggers3@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: <stable@vger.kernel.org>	[4.9+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-29 10:01:37 -07:00
Filipe Manana
f35f06c355 Btrfs: do not allow trimming when a fs is mounted with the nologreplay option
Whan a filesystem is mounted with the nologreplay mount option, which
requires it to be mounted in RO mode as well, we can not allow discard on
free space inside block groups, because log trees refer to extents that
are not pinned in a block group's free space cache (pinning the extents is
precisely the first phase of replaying a log tree).

So do not allow the fitrim ioctl to do anything when the filesystem is
mounted with the nologreplay option, because later it can be mounted RW
without that option, which causes log replay to happen and result in
either a failure to replay the log trees (leading to a mount failure), a
crash or some silent corruption.

Reported-by: Darrick J. Wong <darrick.wong@oracle.com>
Fixes: 96da09192c ("btrfs: Introduce new mount option to disable tree log replay")
CC: stable@vger.kernel.org # 4.9+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-03-28 18:10:27 +01:00
David Howells
8c7ae38d1c afs: Fix StoreData op marshalling
The marshalling of AFS.StoreData, AFS.StoreData64 and YFS.StoreData64 calls
generated by ->setattr() ops for the purpose of expanding a file is
incorrect due to older documentation incorrectly describing the way the RPC
'FileLength' parameter is meant to work.

The older documentation says that this is the length the file is meant to
end up at the end of the operation; however, it was never implemented this
way in any of the servers, but rather the file is truncated down to this
before the write operation is effected, and never expanded to it (and,
indeed, it was renamed to 'TruncPos' in 2014).

Fix this by setting the position parameter to the new file length and doing
a zero-lengh write there.

The bug causes Xwayland to SIGBUS due to unexpected non-expansion of a file
it then mmaps.  This can be tested by giving the following test program a
filename in an AFS directory:

	#include <stdio.h>
	#include <stdlib.h>
	#include <unistd.h>
	#include <fcntl.h>
	#include <sys/mman.h>
	int main(int argc, char *argv[])
	{
		char *p;
		int fd;
		if (argc != 2) {
			fprintf(stderr,
				"Format: test-trunc-mmap <file>\n");
			exit(2);
		}
		fd = open(argv[1], O_RDWR | O_CREAT | O_TRUNC);
		if (fd < 0) {
			perror(argv[1]);
			exit(1);
		}
		if (ftruncate(fd, 0x140008) == -1) {
			perror("ftruncate");
			exit(1);
		}
		p = mmap(NULL, 4096, PROT_READ | PROT_WRITE,
			 MAP_SHARED, fd, 0);
		if (p == MAP_FAILED) {
			perror("mmap");
			exit(1);
		}
		p[0] = 'a';
		if (munmap(p, 4096) < 0) {
			perror("munmap");
			exit(1);
		}
		if (close(fd) < 0) {
			perror("close");
			exit(1);
		}
		exit(0);
	}

Fixes: 31143d5d51 ("AFS: implement basic file write support")
Reported-by: Jonathan Billings <jsbillin@umich.edu>
Tested-by: Jonathan Billings <jsbillin@umich.edu>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-28 08:54:20 -07:00
Al Viro
daf5cc27ee ceph: fix use-after-free on symlink traversal
free the symlink body after the same RCU delay we have for freeing the
struct inode itself, so that traversal during RCU pathwalk wouldn't step
into freed memory.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2019-03-27 19:00:37 +01:00
Linus Torvalds
14c741de93 Merge tag 'nfs-for-5.1-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
Pull NFS client bugfixes from Trond Myklebust:
 "Highlights include:

  Stable fixes:
   - Fix nfs4_lock_state refcounting in nfs4_alloc_{lock,unlock}data()
   - fix mount/umount race in nlmclnt.
   - NFSv4.1 don't free interrupted slot on open

  Bugfixes:
   - Don't let RPC_SOFTCONN tasks time out if the transport is connected
   - Fix a typo in nfs_init_timeout_values()
   - Fix layoutstats handling during read failovers
   - fix uninitialized variable warning"

* tag 'nfs-for-5.1-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  SUNRPC: fix uninitialized variable warning
  pNFS/flexfiles: Fix layoutstats handling during read failovers
  NFS: Fix a typo in nfs_init_timeout_values()
  SUNRPC: Don't let RPC_SOFTCONN tasks time out if the transport is connected
  NFSv4.1 don't free interrupted slot on open
  NFS: fix mount/umount race in nlmclnt.
  NFS: Fix nfs4_lock_state refcounting in nfs4_alloc_{lock,unlock}data()
2019-03-26 14:25:48 -07:00
Linus Torvalds
65ae689329 Merge tag 'for-5.1-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:

 - fsync fixes: i_size for truncate vs fsync, dio vs buffered during
   snapshotting, remove complicated but incomplete assertion

 - removed excessive warnigs, misreported device stats updates

 - fix raid56 page mapping for 32bit arch

 - fixes reported by static analyzer

* tag 'for-5.1-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  Btrfs: fix assertion failure on fsync with NO_HOLES enabled
  btrfs: Avoid possible qgroup_rsv_size overflow in btrfs_calculate_inode_block_rsv_size
  btrfs: Fix bound checking in qgroup_trace_new_subtree_blocks
  btrfs: raid56: properly unmap parity page in finish_parity_scrub()
  btrfs: don't report readahead errors and don't update statistics
  Btrfs: fix file corruption after snapshotting due to mix of buffered/DIO writes
  btrfs: remove WARN_ON in log_dir_items
  Btrfs: fix incorrect file size after shrinking truncate and fsync
2019-03-26 10:32:13 -07:00
Brian Foster
2032a8a27b xfs: serialize unaligned dio writes against all other dio writes
XFS applies more strict serialization constraints to unaligned
direct writes to accommodate things like direct I/O layer zeroing,
unwritten extent conversion, etc. Unaligned submissions acquire the
exclusive iolock and wait for in-flight dio to complete to ensure
multiple submissions do not race on the same block and cause data
corruption.

This generally works in the case of an aligned dio followed by an
unaligned dio, but the serialization is lost if I/Os occur in the
opposite order. If an unaligned write is submitted first and
immediately followed by an overlapping, aligned write, the latter
submits without the typical unaligned serialization barriers because
there is no indication of an unaligned dio still in-flight. This can
lead to unpredictable results.

To provide proper unaligned dio serialization, require that such
direct writes are always the only dio allowed in-flight at one time
for a particular inode. We already acquire the exclusive iolock and
drain pending dio before submitting the unaligned dio. Wait once
more after the dio submission to hold the iolock across the I/O and
prevent further submissions until the unaligned I/O completes. This
is heavy handed, but consistent with the current pre-submission
serialization for unaligned direct writes.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-03-26 08:37:55 -07:00
Sascha Hauer
27942ef503 quota: remove trailing whitespaces
This removes all trailing whitespaces in fs/quota/.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Jan Kara <jack@suse.cz>
2019-03-26 11:21:37 +01:00
Chengguang Xu
df15a2a59d quota: code cleanup for __dquot_alloc_space()
Replace (flags & DQUOT_SPACE_RESERVE) with
variable reserve.

Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2019-03-26 11:21:23 +01:00
Shuning Zhang
1206d028b2 ext2: Adjust the comment of function ext2_alloc_branch
The name of argument is error in the header comment.
@num should be @indirect_blks.
At the same time, there was a lack of description of the two parameters
@blks and @goal.
This commit therefore fixes this header comment.

Signed-off-by: Shuning Zhang <sunny.s.zhang@oracle.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2019-03-26 11:21:23 +01:00
Jan Kara
a768a9abc6 udf: Explain handling of load_nls() failure
Add comment explaining that load_nls() failure gets handled back in
udf_fill_super() to avoid false impression that it is unhandled.

Signed-off-by: Jan Kara <jack@suse.cz>
2019-03-26 11:21:23 +01:00
Roman Penyaev
9bf7933fc3 io_uring: offload write to async worker in case of -EAGAIN
In case of direct write -EAGAIN will be returned if page cache was
previously populated.  To avoid immediate completion of a request
with -EAGAIN error write has to be offloaded to the async worker,
like io_read() does.

Signed-off-by: Roman Penyaev <rpenyaev@suse.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-03-25 13:13:21 -06:00
Arnd Bergmann
9e75ad5d8f io_uring: fix big-endian compat signal mask handling
On big-endian architectures, the signal masks are differnet
between 32-bit and 64-bit tasks, so we have to use a different
function for reading them from user space.

io_cqring_wait() initially got this wrong, and always interprets
this as a native structure. This is ok on x86 and most arm64,
but not on s390, ppc64be, mips64be, sparc64 and parisc.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-03-25 10:06:03 -06:00
Darrick J. Wong
ed79dac98c xfs: prohibit fstrim in norecovery mode
The xfs fstrim implementation uses the free space btrees to find free
space that can be discarded.  If we haven't recovered the log, the bnobt
will be stale and we absolutely *cannot* use stale metadata to zap the
underlying storage.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
2019-03-25 08:03:29 -07:00
Jeff Layton
945ab8f6de locks: wake any locks blocked on request before deadlock check
Andreas reported that he was seeing the tdbtorture test fail in some
cases with -EDEADLCK when it wasn't before. Some debugging showed that
deadlock detection was sometimes discovering the caller's lock request
itself in a dependency chain.

While we remove the request from the blocked_lock_hash prior to
reattempting to acquire it, any locks that are blocked on that request
will still be present in the hash and will still have their fl_blocker
pointer set to the current request.

This causes posix_locks_deadlock to find a deadlock dependency chain
when it shouldn't, as a lock request cannot block itself.

We are going to end up waking all of those blocked locks anyway when we
go to reinsert the request back into the blocked_lock_hash, so just do
it prior to checking for deadlocks. This ensures that any lock blocked
on the current request will no longer be part of any blocked request
chain.

URL: https://bugzilla.kernel.org/show_bug.cgi?id=202975
Fixes: 5946c4319e ("fs/locks: allow a lock request to block other requests.")
Cc: stable@vger.kernel.org
Reported-by: Andreas Schneider <asn@redhat.com>
Signed-off-by: Neil Brown <neilb@suse.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
2019-03-25 08:36:24 -04:00
Linus Torvalds
17403fa277 Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 fixes from Ted Ts'o:
 "Miscellaneous ext4 bug fixes for 5.1"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: prohibit fstrim in norecovery mode
  ext4: cleanup bh release code in ext4_ind_remove_space()
  ext4: brelse all indirect buffer in ext4_ind_remove_space()
  ext4: report real fs size after failed resize
  ext4: add missing brelse() in add_new_gdb_meta_bg()
  ext4: remove useless ext4_pin_inode()
  ext4: avoid panic during forced reboot
  ext4: fix data corruption caused by unaligned direct AIO
  ext4: fix NULL pointer dereference while journal is aborted
2019-03-24 13:41:37 -07:00
Linus Torvalds
19caf581ba Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
 "A set of x86 fixes:

   - Prevent potential NULL pointer dereferences in the HPET and HyperV
     code

   - Exclude the GART aperture from /proc/kcore to prevent kernel
     crashes on access

   - Use the correct macros for Cyrix I/O on Geode processors

   - Remove yet another kernel address printk leak

   - Announce microcode reload completion as requested by quite some
     people. Microcode loading has become popular recently.

   - Some 'Make Clang' happy fixlets

   - A few cleanups for recently added code"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/gart: Exclude GART aperture from kcore
  x86/hw_breakpoints: Make default case in hw_breakpoint_arch_parse() return an error
  x86/mm/pti: Make local symbols static
  x86/cpu/cyrix: Remove {get,set}Cx86_old macros used for Cyrix processors
  x86/cpu/cyrix: Use correct macros for Cyrix calls on Geode processors
  x86/microcode: Announce reload operation's completion
  x86/hyperv: Prevent potential NULL pointer dereference
  x86/hpet: Prevent potential NULL pointer dereference
  x86/lib: Fix indentation issue, remove extra tab
  x86/boot: Restrict header scope to make Clang happy
  x86/mm: Don't leak kernel addresses
  x86/cpufeature: Fix various quality problems in the <asm/cpu_device_hd.h> header
2019-03-24 11:12:27 -07:00
Linus Torvalds
38104c0020 Merge tag '5.1-rc1-cifs-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6
Pull smb3 fixes from Steve French:

 - two fixes for stable for guest mount problems with smb3.1.1

 - two fixes for crediting (SMB3 flow control) on resent requests

 - a byte range lock leak fix

 - two fixes for incorrect rc mappings

* tag '5.1-rc1-cifs-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: update internal module version number
  SMB3: Fix SMB3.1.1 guest mounts to Samba
  cifs: Fix slab-out-of-bounds when tracing SMB tcon
  cifs: allow guest mounts to work for smb3.11
  fix incorrect error code mapping for OBJECTID_NOT_FOUND
  cifs: fix that return -EINVAL when do dedupe operation
  CIFS: Fix an issue with re-sending rdata when transport returning -EAGAIN
  CIFS: Fix an issue with re-sending wdata when transport returning -EAGAIN
2019-03-24 09:58:08 -07:00
Linus Torvalds
1bdd3dbfff Merge tag 'io_uring-20190323' of git://git.kernel.dk/linux-block
Pull io_uring fixes and improvements from Jens Axboe:
 "The first five in this series are heavily inspired by the work Al did
  on the aio side to fix the races there.

  The last two re-introduce a feature that was in io_uring before it got
  merged, but which I pulled since we didn't have a good way to have
  BVEC iters that already have a stable reference. These aren't
  necessarily related to block, it's just how io_uring pins fixed
  buffers"

* tag 'io_uring-20190323' of git://git.kernel.dk/linux-block:
  block: add BIO_NO_PAGE_REF flag
  iov_iter: add ITER_BVEC_FLAG_NO_REF flag
  io_uring: mark me as the maintainer
  io_uring: retry bulk slab allocs as single allocs
  io_uring: fix poll races
  io_uring: fix fget/fput handling
  io_uring: add prepped flag
  io_uring: make io_read/write return an integer
  io_uring: use regular request ref counts
2019-03-23 10:25:12 -07:00
Darrick J. Wong
18915b5873 ext4: prohibit fstrim in norecovery mode
The ext4 fstrim implementation uses the block bitmaps to find free space
that can be discarded.  If we haven't replayed the journal, the bitmaps
will be stale and we absolutely *cannot* use stale metadata to zap the
underlying storage.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2019-03-23 12:10:29 -04:00
Trond Myklebust
166bd5b889 pNFS/flexfiles: Fix layoutstats handling during read failovers
During a read failover, we may end up changing the value of
the pgio_mirror_idx, so make sure that we record the layout
stats before that update.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-03-23 12:03:58 -04:00
Trond Myklebust
5a69824393 NFS: Fix a typo in nfs_init_timeout_values()
Specifying a retrans=0 mount parameter to a NFS/TCP mount, is
inadvertently causing the NFS client to rewrite any specified
timeout parameter to the default of 60 seconds.

Fixes: a956beda19 ("NFS: Allow the mount option retrans=0")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-03-23 12:03:58 -04:00
zhangyi (F)
5e86bdda41 ext4: cleanup bh release code in ext4_ind_remove_space()
Currently, we are releasing the indirect buffer where we are done with
it in ext4_ind_remove_space(), so we can see the brelse() and
BUFFER_TRACE() everywhere.  It seems fragile and hard to read, and we
may probably forget to release the buffer some day.  This patch cleans
up the code by putting of the code which releases the buffers to the
end of the function.

Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
2019-03-23 11:56:01 -04:00
zhangyi (F)
674a2b2723 ext4: brelse all indirect buffer in ext4_ind_remove_space()
All indirect buffers get by ext4_find_shared() should be released no
mater the branch should be freed or not. But now, we forget to release
the lower depth indirect buffers when removing space from the same
higher depth indirect block. It will lead to buffer leak and futher
more, it may lead to quota information corruption when using old quota,
consider the following case.

 - Create and mount an empty ext4 filesystem without extent and quota
   features,
 - quotacheck and enable the user & group quota,
 - Create some files and write some data to them, and then punch hole
   to some files of them, it may trigger the buffer leak problem
   mentioned above.
 - Disable quota and run quotacheck again, it will create two new
   aquota files and write the checked quota information to them, which
   probably may reuse the freed indirect block(the buffer and page
   cache was not freed) as data block.
 - Enable quota again, it will invoke
   vfs_load_quota_inode()->invalidate_bdev() to try to clean unused
   buffers and pagecache. Unfortunately, because of the buffer of quota
   data block is still referenced, quota code cannot read the up to date
   quota info from the device and lead to quota information corruption.

This problem can be reproduced by xfstests generic/231 on ext3 file
system or ext4 file system without extent and quota features.

This patch fix this problem by releasing the missing indirect buffers,
in ext4_ind_remove_space().

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: stable@kernel.org
2019-03-23 11:43:05 -04:00
Kairui Song
ffc8599aa9 x86/gart: Exclude GART aperture from kcore
On machines where the GART aperture is mapped over physical RAM,
/proc/kcore contains the GART aperture range. Accessing the GART range via
/proc/kcore results in a kernel crash.

vmcore used to have the same issue, until it was fixed with commit
2a3e83c6f9 ("x86/gart: Exclude GART aperture from vmcore")', leveraging
existing hook infrastructure in vmcore to let /proc/vmcore return zeroes
when attempting to read the aperture region, and so it won't read from the
actual memory.

Apply the same workaround for kcore. First implement the same hook
infrastructure for kcore, then reuse the hook functions introduced in the
previous vmcore fix. Just with some minor adjustment, rename some functions
for more general usage, and simplify the hook infrastructure a bit as there
is no module usage yet.

Suggested-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Kairui Song <kasong@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jiri Bohac <jbohac@suse.cz>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Dave Young <dyoung@redhat.com>
Link: https://lkml.kernel.org/r/20190308030508.13548-1-kasong@redhat.com
2019-03-23 12:11:49 +01:00
Steve French
cf7d624f8d cifs: update internal module version number
To 2.19

Signed-off-by: Steve French <stfrench@microsoft.com>
2019-03-22 22:43:04 -05:00
Steve French
8c11a607d1 SMB3: Fix SMB3.1.1 guest mounts to Samba
Workaround problem with Samba responses to SMB3.1.1
null user (guest) mounts.  The server doesn't set the
expected flag in the session setup response so we have
to do a similar check to what is done in smb3_validate_negotiate
where we also check if the user is a null user (but not sec=krb5
since username might not be passed in on mount for Kerberos case).

Note that the commit below tightened the conditions and forced signing
for the SMB2-TreeConnect commands as per MS-SMB2.
However, this should only apply to normal user sessions and not for
cases where there is no user (even if server forgets to set the flag
in the response) since we don't have anything useful to sign with.
This is especially important now that the more secure SMB3.1.1 protocol
is in the default dialect list.

An earlier patch ("cifs: allow guest mounts to work for smb3.11") fixed
the guest mounts to Windows.

    Fixes: 6188f28bf6 ("Tree connect for SMB3.1.1 must be signed for non-encrypted shares")

Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Paulo Alcantara <palcantara@suse.de>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-03-22 22:42:49 -05:00
Paulo Alcantara (SUSE)
68ddb49680 cifs: Fix slab-out-of-bounds when tracing SMB tcon
This patch fixes the following KASAN report:

[  779.044746] BUG: KASAN: slab-out-of-bounds in string+0xab/0x180
[  779.044750] Read of size 1 at addr ffff88814f327968 by task trace-cmd/2812

[  779.044756] CPU: 1 PID: 2812 Comm: trace-cmd Not tainted 5.1.0-rc1+ #62
[  779.044760] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-0-ga698c89-prebuilt.qemu.org 04/01/2014
[  779.044761] Call Trace:
[  779.044769]  dump_stack+0x5b/0x90
[  779.044775]  ? string+0xab/0x180
[  779.044781]  print_address_description+0x6c/0x23c
[  779.044787]  ? string+0xab/0x180
[  779.044792]  ? string+0xab/0x180
[  779.044797]  kasan_report.cold.3+0x1a/0x32
[  779.044803]  ? string+0xab/0x180
[  779.044809]  string+0xab/0x180
[  779.044816]  ? widen_string+0x160/0x160
[  779.044822]  ? vsnprintf+0x5bf/0x7f0
[  779.044829]  vsnprintf+0x4e7/0x7f0
[  779.044836]  ? pointer+0x4a0/0x4a0
[  779.044841]  ? seq_buf_vprintf+0x79/0xc0
[  779.044848]  seq_buf_vprintf+0x62/0xc0
[  779.044855]  trace_seq_printf+0x113/0x210
[  779.044861]  ? trace_seq_puts+0x110/0x110
[  779.044867]  ? trace_raw_output_prep+0xd8/0x110
[  779.044876]  trace_raw_output_smb3_tcon_class+0x9f/0xc0
[  779.044882]  print_trace_line+0x377/0x890
[  779.044888]  ? tracing_buffers_read+0x300/0x300
[  779.044893]  ? ring_buffer_read+0x58/0x70
[  779.044899]  s_show+0x6e/0x140
[  779.044906]  seq_read+0x505/0x6a0
[  779.044913]  vfs_read+0xaf/0x1b0
[  779.044919]  ksys_read+0xa1/0x130
[  779.044925]  ? kernel_write+0xa0/0xa0
[  779.044931]  ? __do_page_fault+0x3d5/0x620
[  779.044938]  do_syscall_64+0x63/0x150
[  779.044944]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[  779.044949] RIP: 0033:0x7f62c2c2db31
[ 779.044955] Code: fe ff ff 48 8d 3d 17 9e 09 00 48 83 ec 08 e8 96 02
02 00 66 0f 1f 44 00 00 8b 05 fa fc 2c 00 48 63 ff 85 c0 75 13 31 c0
0f 05 <48> 3d 00 f0 ff ff 77 57 f3 c3 0f 1f 44 00 00 55 53 48 89 d5 48
89
[  779.044958] RSP: 002b:00007ffd6e116678 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
[  779.044964] RAX: ffffffffffffffda RBX: 0000560a38be9260 RCX: 00007f62c2c2db31
[  779.044966] RDX: 0000000000002000 RSI: 00007ffd6e116710 RDI: 0000000000000003
[  779.044966] RDX: 0000000000002000 RSI: 00007ffd6e116710 RDI: 0000000000000003
[  779.044969] RBP: 00007f62c2ef5420 R08: 0000000000000000 R09: 0000000000000003
[  779.044972] R10: ffffffffffffffa8 R11: 0000000000000246 R12: 00007ffd6e116710
[  779.044975] R13: 0000000000002000 R14: 0000000000000d68 R15: 0000000000002000

[  779.044981] Allocated by task 1257:
[  779.044987]  __kasan_kmalloc.constprop.5+0xc1/0xd0
[  779.044992]  kmem_cache_alloc+0xad/0x1a0
[  779.044997]  getname_flags+0x6c/0x2a0
[  779.045003]  user_path_at_empty+0x1d/0x40
[  779.045008]  do_faccessat+0x12a/0x330
[  779.045012]  do_syscall_64+0x63/0x150
[  779.045017]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

[  779.045019] Freed by task 1257:
[  779.045023]  __kasan_slab_free+0x12e/0x180
[  779.045029]  kmem_cache_free+0x85/0x1b0
[  779.045034]  filename_lookup.part.70+0x176/0x250
[  779.045039]  do_faccessat+0x12a/0x330
[  779.045043]  do_syscall_64+0x63/0x150
[  779.045048]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

[  779.045052] The buggy address belongs to the object at ffff88814f326600
which belongs to the cache names_cache of size 4096
[  779.045057] The buggy address is located 872 bytes to the right of
4096-byte region [ffff88814f326600, ffff88814f327600)
[  779.045058] The buggy address belongs to the page:
[  779.045062] page:ffffea00053cc800 count:1 mapcount:0 mapping:ffff88815b191b40 index:0x0 compound_mapcount: 0
[  779.045067] flags: 0x200000000010200(slab|head)
[  779.045075] raw: 0200000000010200 dead000000000100 dead000000000200 ffff88815b191b40
[  779.045081] raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000
[  779.045083] page dumped because: kasan: bad access detected

[  779.045085] Memory state around the buggy address:
[  779.045089]  ffff88814f327800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  779.045093]  ffff88814f327880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  779.045097] >ffff88814f327900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  779.045099]                                                           ^
[  779.045103]  ffff88814f327980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  779.045107]  ffff88814f327a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  779.045109] ==================================================================
[  779.045110] Disabling lock debugging due to kernel taint

Correctly assign tree name str for smb3_tcon event.

Signed-off-by: Paulo Alcantara (SUSE) <paulo@paulo.ac>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-03-22 22:36:54 -05:00
Ronnie Sahlberg
e71ab2aa06 cifs: allow guest mounts to work for smb3.11
Fix Guest/Anonymous sessions so that they work with SMB 3.11.

The commit noted below tightened the conditions and forced signing for
the SMB2-TreeConnect commands as per MS-SMB2.
However, this should only apply to normal user sessions and not for
Guest/Anonumous sessions.

Fixes: 6188f28bf6 ("Tree connect for SMB3.1.1 must be signed for non-encrypted shares")

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-03-22 22:36:54 -05:00
Steve French
85f9987b23 fix incorrect error code mapping for OBJECTID_NOT_FOUND
It was mapped to EIO which can be confusing when user space
queries for an object GUID for an object for which the server
file system doesn't support (or hasn't saved one).

As Amir Goldstein suggested this is similar to ENOATTR
(equivalently ENODATA in Linux errno definitions) so
changing NT STATUS code mapping for OBJECTID_NOT_FOUND
to ENODATA.

Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Amir Goldstein <amir73il@gmail.com>
2019-03-22 22:36:54 -05:00
Xiaoli Feng
b073a08016 cifs: fix that return -EINVAL when do dedupe operation
dedupe_file_range operations is combiled into remap_file_range.
But it's always skipped for dedupe operations in function
cifs_remap_file_range.

Example to test:
Before this patch:
  # dd if=/dev/zero of=cifs/file bs=1M count=1
  # xfs_io -c "dedupe cifs/file 4k 64k 4k" cifs/file
  XFS_IOC_FILE_EXTENT_SAME: Invalid argument

After this patch:
  # dd if=/dev/zero of=cifs/file bs=1M count=1
  # xfs_io -c "dedupe cifs/file 4k 64k 4k" cifs/file
  XFS_IOC_FILE_EXTENT_SAME: Operation not supported

Influence for xfstests:
generic/091
generic/112
generic/127
generic/263
These tests report this error "do_copy_range:: Invalid
argument" instead of "FIDEDUPERANGE: Invalid argument".
Because there are still two bugs cause these test failed.
https://bugzilla.kernel.org/show_bug.cgi?id=202935
https://bugzilla.kernel.org/show_bug.cgi?id=202785

Signed-off-by: Xiaoli Feng <fengxiaoli0714@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-03-22 22:36:54 -05:00
Long Li
0b0dfd5921 CIFS: Fix an issue with re-sending rdata when transport returning -EAGAIN
When sending a rdata, transport may return -EAGAIN. In this case
we should re-obtain credits because the session may have been
reconnected.

Change in v2: adjust_credits before re-sending

Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2019-03-22 22:36:54 -05:00
Long Li
d53e292f0f CIFS: Fix an issue with re-sending wdata when transport returning -EAGAIN
When sending a wdata, transport may return -EAGAIN. In this case
we should re-obtain credits because the session may have been
reconnected.

Change in v2: adjust_credits before re-sending

Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2019-03-22 22:36:54 -05:00
Arnd Bergmann
a5fdd713d2 jfs: fix bogus variable self-initialization
A statement was originally added in 2006 to shut up a gcc warning,
now but now clang warns about it:

fs/jfs/jfs_txnmgr.c:1932:15: error: variable 'pxd' is uninitialized when used within its own initialization
      [-Werror,-Wuninitialized]
                pxd_t pxd = pxd;        /* truncated extent of xad */
                      ~~~   ^~~

Modern versions of gcc are fine without the silly assignment, so just
drop it. Tested with gcc-4.6 (released 2011), 4.7, 4.8, and 4.9.

Fixes: c9e3ad6021 ("JFS: Get rid of "may be used uninitialized" warnings")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
2019-03-22 09:38:37 -05:00
Linus Torvalds
0939221e64 Merge tag 'fixes_for_v5.1-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
Pull udf fixes from Jan Kara:
 "Two udf error handling fixes"

* tag 'fixes_for_v5.1-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  udf: Propagate errors from udf_truncate_extents()
  udf: Fix crash on IO error during truncate
2019-03-21 10:31:55 -07:00
Linus Torvalds
7294fbd441 Merge tag 'fsnotify_for_v5.1-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
Pull fsnotify fixes from Jan Kara:
 "One inotify and one fanotify fix"

* tag 'fsnotify_for_v5.1-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  fanotify: Allow copying of file handle to userspace
  inotify: Fix fsnotify_mark refcount leak in inotify_update_existing_watch()
2019-03-21 10:24:00 -07:00
Ondrej Mosnacek
e19dfdc83b kernfs: initialize security of newly created nodes
Use the new security_kernfs_init_security() hook to allow LSMs to
possibly assign a non-default security context to a newly created kernfs
node based on the attributes of the new node and also its parent node.

This fixes an issue with cgroupfs under SELinux, where newly created
cgroup subdirectories/files would not inherit its parent's context if
it had been set explicitly to a non-default value (other than the genfs
context specified by the policy). This can be reproduced as follows (on
Fedora/RHEL):

    # mkdir /sys/fs/cgroup/unified/test
    # # Need permissive to change the label under Fedora policy:
    # setenforce 0
    # chcon -t container_file_t /sys/fs/cgroup/unified/test
    # ls -lZ /sys/fs/cgroup/unified
    total 0
    -r--r--r--.  1 root root system_u:object_r:cgroup_t:s0         0 Jan 29 03:06 cgroup.controllers
    -rw-r--r--.  1 root root system_u:object_r:cgroup_t:s0         0 Jan 29 03:06 cgroup.max.depth
    -rw-r--r--.  1 root root system_u:object_r:cgroup_t:s0         0 Jan 29 03:06 cgroup.max.descendants
    -rw-r--r--.  1 root root system_u:object_r:cgroup_t:s0         0 Jan 29 03:06 cgroup.procs
    -r--r--r--.  1 root root system_u:object_r:cgroup_t:s0         0 Jan 29 03:06 cgroup.stat
    -rw-r--r--.  1 root root system_u:object_r:cgroup_t:s0         0 Jan 29 03:06 cgroup.subtree_control
    -rw-r--r--.  1 root root system_u:object_r:cgroup_t:s0         0 Jan 29 03:06 cgroup.threads
    drwxr-xr-x.  2 root root system_u:object_r:cgroup_t:s0         0 Jan 29 03:06 init.scope
    drwxr-xr-x. 26 root root system_u:object_r:cgroup_t:s0         0 Jan 29 03:21 system.slice
    drwxr-xr-x.  3 root root system_u:object_r:container_file_t:s0 0 Jan 29 03:15 test
    drwxr-xr-x.  3 root root system_u:object_r:cgroup_t:s0         0 Jan 29 03:06 user.slice
    # mkdir /sys/fs/cgroup/unified/test/subdir

Actual result:

    # ls -ldZ /sys/fs/cgroup/unified/test/subdir
    drwxr-xr-x. 2 root root system_u:object_r:cgroup_t:s0 0 Jan 29 03:15 /sys/fs/cgroup/unified/test/subdir

Expected result:

    # ls -ldZ /sys/fs/cgroup/unified/test/subdir
    drwxr-xr-x. 2 root root unconfined_u:object_r:container_file_t:s0 0 Jan 29 03:15 /sys/fs/cgroup/unified/test/subdir

Link: https://github.com/SELinuxProject/selinux-kernel/issues/39

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-03-20 22:10:15 -04:00
Ondrej Mosnacek
b230d5aba2 LSM: add new hook for kernfs node initialization
This patch introduces a new security hook that is intended for
initializing the security data for newly created kernfs nodes, which
provide a way of storing a non-default security context, but need to
operate independently from mounts (and therefore may not have an
associated inode at the moment of creation).

The main motivation is to allow kernfs nodes to inherit the context of
the parent under SELinux, similar to the behavior of
security_inode_init_security(). Other LSMs may implement their own logic
for handling the creation of new nodes.

This patch also adds helper functions to <linux/kernfs.h> for
getting/setting security xattrs of a kernfs node so that LSMs hooks are
able to do their job. Other important attributes should be accessible
direcly in the kernfs_node fields (in case there is need for more, then
new helpers should be added to kernfs.h along with the patch that needs
them).

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: more manual merge fixes]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-03-20 22:01:02 -04:00
Ondrej Mosnacek
0ac6075a32 kernfs: use simple_xattrs for security attributes
Replace the special handling of security xattrs with simple_xattrs, as
is already done for the trusted xattrs. This simplifies the code and
allows LSMs to use more than just a single xattr to do their business.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: manual merge fixes]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-03-20 21:54:33 -04:00
Ondrej Mosnacek
d0c9c153b4 kernfs: do not alloc iattrs in kernfs_xattr_get
This is a read-only operation, so we can simply return -ENODATA if
kn->iattr is NULL.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: minor merge fixes]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-03-20 21:47:36 -04:00
Ondrej Mosnacek
0589521962 kernfs: clean up struct kernfs_iattrs
Right now, kernfs_iattrs embeds the whole struct iattr, even though it
doesn't really use half of its fields... This both leads to wasting
space and makes the code look awkward. Let's just list the few fields
we need directly in struct kernfs_iattrs.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: merged a number of chunks manually due to fuzz]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-03-20 21:42:14 -04:00
David Howells
cf3cba4a42 vfs: syscall: Add fspick() to select a superblock for reconfiguration
Provide an fspick() system call that can be used to pick an existing
mountpoint into an fs_context which can thereafter be used to reconfigure a
superblock (equivalent of the superblock side of -o remount).

This looks like:

	int fd = fspick(AT_FDCWD, "/mnt",
			FSPICK_CLOEXEC | FSPICK_NO_AUTOMOUNT);
	fsconfig(fd, FSCONFIG_SET_FLAG, "intr", NULL, 0);
	fsconfig(fd, FSCONFIG_SET_FLAG, "noac", NULL, 0);
	fsconfig(fd, FSCONFIG_CMD_RECONFIGURE, NULL, NULL, 0);

At the point of fspick being called, the file descriptor referring to the
filesystem context is in exactly the same state as the one that was created
by fsopen() after fsmount() has been successfully called.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-api@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-03-20 18:49:06 -04:00
David Howells
93766fbd26 vfs: syscall: Add fsmount() to create a mount for a superblock
Provide a system call by which a filesystem opened with fsopen() and
configured by a series of fsconfig() calls can have a detached mount object
created for it.  This mount object can then be attached to the VFS mount
hierarchy using move_mount() by passing the returned file descriptor as the
from directory fd.

The system call looks like:

	int mfd = fsmount(int fsfd, unsigned int flags,
			  unsigned int attr_flags);

where fsfd is the file descriptor returned by fsopen().  flags can be 0 or
FSMOUNT_CLOEXEC.  attr_flags is a bitwise-OR of the following flags:

	MOUNT_ATTR_RDONLY	Mount read-only
	MOUNT_ATTR_NOSUID	Ignore suid and sgid bits
	MOUNT_ATTR_NODEV	Disallow access to device special files
	MOUNT_ATTR_NOEXEC	Disallow program execution
	MOUNT_ATTR__ATIME	Setting on how atime should be updated
	MOUNT_ATTR_RELATIME	- Update atime relative to mtime/ctime
	MOUNT_ATTR_NOATIME	- Do not update access times
	MOUNT_ATTR_STRICTATIME	- Always perform atime updates
	MOUNT_ATTR_NODIRATIME	Do not update directory access times

In the event that fsmount() fails, it may be possible to get an error
message by calling read() on fsfd.  If no message is available, ENODATA
will be reported.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-api@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-03-20 18:49:06 -04:00
David Howells
ecdab150fd vfs: syscall: Add fsconfig() for configuring and managing a context
Add a syscall for configuring a filesystem creation context and triggering
actions upon it, to be used in conjunction with fsopen, fspick and fsmount.

    long fsconfig(int fs_fd, unsigned int cmd, const char *key,
		  const void *value, int aux);

Where fs_fd indicates the context, cmd indicates the action to take, key
indicates the parameter name for parameter-setting actions and, if needed,
value points to a buffer containing the value and aux can give more
information for the value.

The following command IDs are proposed:

 (*) FSCONFIG_SET_FLAG: No value is specified.  The parameter must be
     boolean in nature.  The key may be prefixed with "no" to invert the
     setting. value must be NULL and aux must be 0.

 (*) FSCONFIG_SET_STRING: A string value is specified.  The parameter can
     be expecting boolean, integer, string or take a path.  A conversion to
     an appropriate type will be attempted (which may include looking up as
     a path).  value points to a NUL-terminated string and aux must be 0.

 (*) FSCONFIG_SET_BINARY: A binary blob is specified.  value points to
     the blob and aux indicates its size.  The parameter must be expecting
     a blob.

 (*) FSCONFIG_SET_PATH: A non-empty path is specified.  The parameter must
     be expecting a path object.  value points to a NUL-terminated string
     that is the path and aux is a file descriptor at which to start a
     relative lookup or AT_FDCWD.

 (*) FSCONFIG_SET_PATH_EMPTY: As fsconfig_set_path, but with AT_EMPTY_PATH
     implied.

 (*) FSCONFIG_SET_FD: An open file descriptor is specified.  value must
     be NULL and aux indicates the file descriptor.

 (*) FSCONFIG_CMD_CREATE: Trigger superblock creation.

 (*) FSCONFIG_CMD_RECONFIGURE: Trigger superblock reconfiguration.

For the "set" command IDs, the idea is that the file_system_type will point
to a list of parameters and the types of value that those parameters expect
to take.  The core code can then do the parse and argument conversion and
then give the LSM and FS a cooked option or array of options to use.

Source specification is also done the same way same way, using special keys
"source", "source1", "source2", etc..

[!] Note that, for the moment, the key and value are just glued back
together and handed to the filesystem.  Every filesystem that uses options
uses match_token() and co. to do this, and this will need to be changed -
but not all at once.

Example usage:

    fd = fsopen("ext4", FSOPEN_CLOEXEC);
    fsconfig(fd, fsconfig_set_path, "source", "/dev/sda1", AT_FDCWD);
    fsconfig(fd, fsconfig_set_path_empty, "journal_path", "", journal_fd);
    fsconfig(fd, fsconfig_set_fd, "journal_fd", "", journal_fd);
    fsconfig(fd, fsconfig_set_flag, "user_xattr", NULL, 0);
    fsconfig(fd, fsconfig_set_flag, "noacl", NULL, 0);
    fsconfig(fd, fsconfig_set_string, "sb", "1", 0);
    fsconfig(fd, fsconfig_set_string, "errors", "continue", 0);
    fsconfig(fd, fsconfig_set_string, "data", "journal", 0);
    fsconfig(fd, fsconfig_set_string, "context", "unconfined_u:...", 0);
    fsconfig(fd, fsconfig_cmd_create, NULL, NULL, 0);
    mfd = fsmount(fd, FSMOUNT_CLOEXEC, MS_NOEXEC);

or:

    fd = fsopen("ext4", FSOPEN_CLOEXEC);
    fsconfig(fd, fsconfig_set_string, "source", "/dev/sda1", 0);
    fsconfig(fd, fsconfig_cmd_create, NULL, NULL, 0);
    mfd = fsmount(fd, FSMOUNT_CLOEXEC, MS_NOEXEC);

or:

    fd = fsopen("afs", FSOPEN_CLOEXEC);
    fsconfig(fd, fsconfig_set_string, "source", "#grand.central.org:root.cell", 0);
    fsconfig(fd, fsconfig_cmd_create, NULL, NULL, 0);
    mfd = fsmount(fd, FSMOUNT_CLOEXEC, MS_NOEXEC);

or:

    fd = fsopen("jffs2", FSOPEN_CLOEXEC);
    fsconfig(fd, fsconfig_set_string, "source", "mtd0", 0);
    fsconfig(fd, fsconfig_cmd_create, NULL, NULL, 0);
    mfd = fsmount(fd, FSMOUNT_CLOEXEC, MS_NOEXEC);

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-api@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-03-20 18:49:06 -04:00
David Howells
007ec26cdc vfs: Implement logging through fs_context
Implement the ability for filesystems to log error, warning and
informational messages through the fs_context.  These can be extracted by
userspace by reading from an fd created by fsopen().

Error messages are prefixed with "e ", warnings with "w " and informational
messages with "i ".

Inside the kernel, formatted messages are malloc'd but unformatted messages
are not copied if they're either in the core .rodata section or in the
.rodata section of the filesystem module pinned by fs_context::fs_type.
The messages are only good till the fs_type is released.

Note that the logging object is shared between duplicated fs_context
structures.  This is so that such as NFS which do a mount within a mount
can get at least some of the errors from the inner mount.

Five logging functions are provided for this:

 (1) void logfc(struct fs_context *fc, const char *fmt, ...);

     This logs a message into the context.  If the buffer is full, the
     earliest message is discarded.

 (2) void errorf(fc, fmt, ...);

     This wraps logfc() to log an error.

 (3) void invalf(fc, fmt, ...);

     This wraps errorf() and returns -EINVAL for convenience.

 (4) void warnf(fc, fmt, ...);

     This wraps logfc() to log a warning.

 (5) void infof(fc, fmt, ...);

     This wraps logfc() to log an informational message.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-03-20 18:49:06 -04:00
David Howells
24dcb3d90a vfs: syscall: Add fsopen() to prepare for superblock creation
Provide an fsopen() system call that starts the process of preparing to
create a superblock that will then be mountable, using an fd as a context
handle.  fsopen() is given the name of the filesystem that will be used:

	int mfd = fsopen(const char *fsname, unsigned int flags);

where flags can be 0 or FSOPEN_CLOEXEC.

For example:

	sfd = fsopen("ext4", FSOPEN_CLOEXEC);
	fsconfig(sfd, FSCONFIG_SET_PATH, "source", "/dev/sda1", AT_FDCWD);
	fsconfig(sfd, FSCONFIG_SET_FLAG, "noatime", NULL, 0);
	fsconfig(sfd, FSCONFIG_SET_FLAG, "acl", NULL, 0);
	fsconfig(sfd, FSCONFIG_SET_FLAG, "user_xattr", NULL, 0);
	fsconfig(sfd, FSCONFIG_SET_STRING, "sb", "1", 0);
	fsconfig(sfd, FSCONFIG_CMD_CREATE, NULL, NULL, 0);
	fsinfo(sfd, NULL, ...); // query new superblock attributes
	mfd = fsmount(sfd, FSMOUNT_CLOEXEC, MS_RELATIME);
	move_mount(mfd, "", sfd, AT_FDCWD, "/mnt", MOVE_MOUNT_F_EMPTY_PATH);

	sfd = fsopen("afs", -1);
	fsconfig(fd, FSCONFIG_SET_STRING, "source",
		 "#grand.central.org:root.cell", 0);
	fsconfig(fd, FSCONFIG_CMD_CREATE, NULL, NULL, 0);
	mfd = fsmount(sfd, 0, MS_NODEV);
	move_mount(mfd, "", sfd, AT_FDCWD, "/mnt", MOVE_MOUNT_F_EMPTY_PATH);

If an error is reported at any step, an error message may be available to be
read() back (ENODATA will be reported if there isn't an error available) in
the form:

	"e <subsys>:<problem>"
	"e SELinux:Mount on mountpoint not permitted"

Once fsmount() has been called, further fsconfig() calls will incur EBUSY,
even if the fsmount() fails.  read() is still possible to retrieve error
information.

The fsopen() syscall creates a mount context and hangs it of the fd that it
returns.

Netlink is not used because it is optional and would make the core VFS
dependent on the networking layer and also potentially add network
namespace issues.

Note that, for the moment, the caller must have SYS_CAP_ADMIN to use
fsopen().

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-api@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-03-20 18:49:06 -04:00
David Howells
dadd2299ab Make anon_inodes unconditional
Make the anon_inodes facility unconditional so that it can be used by core
VFS code.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-03-20 18:49:06 -04:00
David Howells
44dfd84a6d teach move_mount(2) to work with OPEN_TREE_CLONE
Allow a detached tree created by open_tree(..., OPEN_TREE_CLONE) to be
attached by move_mount(2).

If by the time of final fput() of OPEN_TREE_CLONE-opened file its tree is
not detached anymore, it won't be dissolved.  move_mount(2) is adjusted
to handle detached source.

That gives us equivalents of mount --bind and mount --rbind.

Thanks also to Alan Jenkins <alan.christopher.jenkins@gmail.com> for
providing a whole bunch of ways to break things using this interface.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-03-20 18:49:06 -04:00
David Howells
2db154b3ea vfs: syscall: Add move_mount(2) to move mounts around
Add a move_mount() system call that will move a mount from one place to
another and, in the next commit, allow to attach an unattached mount tree.

The new system call looks like the following:

	int move_mount(int from_dfd, const char *from_path,
		       int to_dfd, const char *to_path,
		       unsigned int flags);

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-api@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-03-20 18:49:06 -04:00
Al Viro
a07b200047 vfs: syscall: Add open_tree(2) to reference or clone a mount
open_tree(dfd, pathname, flags)

Returns an O_PATH-opened file descriptor or an error.
dfd and pathname specify the location to open, in usual
fashion (see e.g. fstatat(2)).  flags should be an OR of
some of the following:
	* AT_PATH_EMPTY, AT_NO_AUTOMOUNT, AT_SYMLINK_NOFOLLOW -
same meanings as usual
	* OPEN_TREE_CLOEXEC - make the resulting descriptor
close-on-exec
	* OPEN_TREE_CLONE or OPEN_TREE_CLONE | AT_RECURSIVE -
instead of opening the location in question, create a detached
mount tree matching the subtree rooted at location specified by
dfd/pathname.  With AT_RECURSIVE the entire subtree is cloned,
without it - only the part within in the mount containing the
location in question.  In other words, the same as mount --rbind
or mount --bind would've taken.  The detached tree will be
dissolved on the final close of obtained file.  Creation of such
detached trees requires the same capabilities as doing mount --bind.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-api@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-03-20 18:49:06 -04:00