Commit Graph

3524 Commits

Author SHA1 Message Date
Long Li
4ebb8795a7 cifs: smbd: Check and extend sender credits in interrupt context
When a RDMA packet is received and server is extending send credits, we should
check and unblock senders immediately in IRQ context. Doing it in a worker
queue causes unnecessary delay and doesn't save much CPU on the receive path.

Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-03-29 16:42:36 -05:00
Long Li
f7950cb05d cifs: smbd: Calculate the correct maximum packet size for segmented SMBDirect send/receive
The packet size needs to take account of SMB2 header size and possible
encryption header size. This is only done when signing is used and it is for
RDMA send/receive, not read/write.

Also remove the dead SMBD code in smb2_negotiate_r(w)size.

Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-03-29 16:41:49 -05:00
Steve French
edad734c74 smb3: use SMB2_SIGNATURE_SIZE define
It clarifies the code slightly to use SMB2_SIGNATURE_SIZE
define rather than 16.

Suggested-by: Henning Schild <henning.schild@siemens.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-03-27 12:47:41 -05:00
Yilu Lin
97adda8b3a CIFS: Fix bug which the return value by asynchronous read is error
This patch is used to fix the bug in collect_uncached_read_data()
that rc is automatically converted from a signed number to an
unsigned number when the CIFS asynchronous read fails.
It will cause ctx->rc is error.

Example:
Share a directory and create a file on the Windows OS.
Mount the directory to the Linux OS using CIFS.
On the CIFS client of the Linux OS, invoke the pread interface to
deliver the read request.

The size of the read length plus offset of the read request is greater
than the maximum file size.

In this case, the CIFS server on the Windows OS returns a failure
message (for example, the return value of
smb2.nt_status is STATUS_INVALID_PARAMETER).

After receiving the response message, the CIFS client parses
smb2.nt_status to STATUS_INVALID_PARAMETER
and converts it to the Linux error code (rdata->result=-22).

Then the CIFS client invokes the collect_uncached_read_data function to
assign the value of rdata->result to rc, that is, rc=rdata->result=-22.

The type of the ctx->total_len variable is unsigned integer,
the type of the rc variable is integer, and the type of
the ctx->rc variable is ssize_t.

Therefore, during the ternary operation, the value of rc is
automatically converted to an unsigned number. The final result is
ctx->rc=4294967274. However, the expected result is ctx->rc=-22.

Signed-off-by: Yilu Lin <linyilu@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
2020-03-22 22:49:10 -05:00
Murphy Zhou
ef4a632ccc CIFS: check new file size when extending file by fallocate
xfstests generic/228 checks if fallocate respect RLIMIT_FSIZE.
After fallocate mode 0 extending enabled, we can hit this failure.
Fix this by check the new file size with vfs helper, return
error if file size is larger then RLIMIT_FSIZE(ulimit -f).

This patch has been tested by LTP/xfstests aginst samba and
Windows server.

Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Murphy Zhou <jencce.kernel@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
2020-03-22 22:49:10 -05:00
Steve French
8895c66f2b SMB3: Minor cleanup of protocol definitions
And add one missing define (COMPRESSION_TRANSFORM_ID) and
flag (TRANSFORM_FLAG_ENCRYPTED)

Signed-off-by: Steve French <stfrench@microsoft.com>
2020-03-22 22:49:10 -05:00
Steve French
8f23343131 SMB3: Additional compression structures
New transform header structures. See recent updates
to MS-SMB2 adding section 2.2.42.1 and 2.2.42.2

Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
2020-03-22 22:49:10 -05:00
Steve French
2fe4f62de4 SMB3: Add new compression flags
Additional compression capabilities can now be negotiated and a
new compression algorithm.  Add the flags for these.

See newly updated MS-SMB2 sections 3.1.4.4.1 and 2.2.3.1.3

Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
2020-03-22 22:49:10 -05:00
Gustavo A. R. Silva
cff2def598 cifs: smb2pdu.h: Replace zero-length array with flexible-array member
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-03-22 22:49:10 -05:00
Eric Biggers
dc920277f1 cifs: clear PF_MEMALLOC before exiting demultiplex thread
Leaving PF_MEMALLOC set when exiting a kthread causes it to remain set
during do_exit().  That can confuse things.  For example, if BSD process
accounting is enabled and the accounting file has FS_SYNC_FL set and is
located on an ext4 filesystem without a journal, then do_exit() can end
up calling ext4_write_inode().  That triggers the
WARN_ON_ONCE(current->flags & PF_MEMALLOC) there, as it assumes
(appropriately) that inodes aren't written when allocating memory.

This was originally reported for another kernel thread, xfsaild() [1].
cifs_demultiplex_thread() also exits with PF_MEMALLOC set, so it's
potentially subject to this same class of issue -- though I haven't been
able to reproduce the WARN_ON_ONCE() via CIFS, since unlike xfsaild(),
cifs_demultiplex_thread() is sent SIGKILL before exiting, and that
interrupts the write to the BSD process accounting file.

Either way, leaving PF_MEMALLOC set is potentially problematic.  Let's
clean this up by properly saving and restoring PF_MEMALLOC.

[1] https://lore.kernel.org/r/0000000000000e7156059f751d7b@google.com

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-03-22 22:49:10 -05:00
Gustavo A. R. Silva
266b9fecc5 cifs: cifspdu.h: Replace zero-length array with flexible-array member
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-03-22 22:49:10 -05:00
Steve French
ba55344f36 CIFS: Warn less noisily on default mount
The warning we print on mount about how to use less secure dialects
(when the user does not specify a version on mount) is useful
but is noisy to print on every default mount, and can be changed
to a warn_once.  Slightly updated the warning text as well to note
SMB3.1.1 which has been the default which is typically negotiated
(for a few years now) by most servers.

      "No dialect specified on mount. Default has changed to a more
       secure dialect, SMB2.1 or later (e.g. SMB3.1.1), from CIFS
       (SMB1). To use the less secure SMB1 dialect to access old
       servers which do not support SMB3.1.1 (or even SMB3 or SMB2.1)
       specify vers=1.0 on mount."

Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
2020-03-22 22:49:09 -05:00
Qiujun Huang
f2d67931fd fs/cifs: fix gcc warning in sid_to_id
fix warning [-Wunused-but-set-variable] at variable 'rc',
keeping the code readable.

Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-03-22 22:49:09 -05:00
Murphy Zhou
0667059d0b cifs: allow unlock flock and OFD lock across fork
Since commit d0677992d2 ("cifs: add support for flock") added
support for flock, LTP/flock03[1] testcase started to fail.

This testcase is testing flock lock and unlock across fork.
The parent locks file and starts the child process, in which
it unlock the same fd and lock the same file with another fd
again. All the lock and unlock operation should succeed.

Now the child process does not actually unlock the file, so
the following lock fails. Fix this by allowing flock and OFD
lock go through the unlock routine, not skipping if the unlock
request comes from another process.

Patch has been tested by LTP/xfstests on samba and Windows
server, v3.11, with or without cache=none mount option.

[1] https://github.com/linux-test-project/ltp/blob/master/testcases/kernel/syscalls/flock/flock03.c
Signed-off-by: Murphy Zhou <jencce.kernel@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Pavel Shilovsky <pshilov@microsoft.com>
2020-03-22 22:49:09 -05:00
Steve French
c7e9f78f7b cifs: do d_move in rename
See commit 349457ccf2
"Allow file systems to manually d_move() inside of ->rename()"

Lessens possibility of race conditions in rename

Signed-off-by: Steve French <stfrench@microsoft.com>
2020-03-22 22:49:09 -05:00
Aurelien Aptel
69dda3059e cifs: add SMB2_open() arg to return POSIX data
allows SMB2_open() callers to pass down a POSIX data buffer that will
trigger requesting POSIX create context and parsing the response into
the provided buffer.

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
2020-03-22 22:49:09 -05:00
Aurelien Aptel
3d519bd126 cifs: plumb smb2 POSIX dir enumeration
* add code to request POSIX info level
* parse dir entries and fill cifs_fattr to get correct inode data

since the POSIX payload is variable size the number of entries in a
FIND response needs to be computed differently.

Dirs and regular files are properly reported along with mode bits,
hardlink number, c/m/atime. No special files yet (see below).

Current experimental version of Samba with the extension unfortunately
has issues with wildcards and needs the following patch:

> --- i/source3/smbd/smb2_query_directory.c
> +++ w/source3/smbd/smb2_query_directory.c
> @@ -397,9 +397,7 @@ smbd_smb2_query_directory_send(TALLOC_CTX
> *mem_ctx,
> 		}
> 	}
>
> -       if (!state->smbreq->posix_pathnames) {
> 		wcard_has_wild = ms_has_wild(state->in_file_name);
> -       }
>
> 	/* Ensure we've canonicalized any search path if not a wildcard. */
> 	if (!wcard_has_wild) {
>

Also for special files despite reporting them as reparse point samba
doesn't set the reparse tag field. This patch will mark them as needing
re-evaluation but the re-evaluate code doesn't deal with it yet.

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-03-22 22:49:09 -05:00
Aurelien Aptel
349e13ad30 cifs: add smb2 POSIX info level
* add new info level and structs for SMB2 posix extension
* add functions to parse and validate it

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-03-22 22:49:09 -05:00
Aurelien Aptel
2e8af978d9 cifs: rename posix create rsp
little progress on the posix create response.

* rename struct to create_posix_rsp to match with the request
  create_posix context
* make struct packed
* pass smb info struct for parse_posix_ctxt to fill
* use smb info struct as param
* update TODO

What needs to be done:

SMB2_open() has an optional smb info out argument that it will fill.
Callers making use of this are:

- smb3_query_mf_symlink (need to investigate)
- smb2_open_file

Callers of smb2_open_file (via server->ops->open) are passing an
smbinfo struct but that struct cannot hold POSIX information. All the
call stack needs to be changed for a different info type. Maybe pass
SMB generic struct like cifs_fattr instead.

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-03-22 22:49:09 -05:00
Steve French
8fe0c2c2cb cifs: print warning mounting with vers=1.0
We really, really don't want people using insecure dialects
unless they realize what they are doing ...

Add mount warning if mounting with vers=1.0 (older SMB1/CIFS
dialect) instead of the default (SMB2.1 or later, typically
SMB3.1.1).

Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
Acked-by: Pavel Shilovsky <pshilov@microsoft.com>
2020-03-22 22:49:09 -05:00
Steve French
cf5371ae46 smb3: fix performance regression with setting mtime
There are cases when we don't want to send the SMB2 flush operation
(e.g. when user specifies mount parm "nostrictsync") and it can be
a very expensive operation on the server.  In most cases in order
to set mtime, we simply need to flush (write) the dirtry pages from
the client and send the writes to the server not also send a flush
protocol operation to the server.

Fixes: aa081859b1 ("cifs: flush before set-info if we have writeable handles")
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-03-22 22:49:09 -05:00
Stefan Metzmacher
864138cb31 cifs: make use of cap_unix(ses) in cifs_reconnect_tcon()
cap_unix(ses) defaults to false for SMB2.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-03-22 22:49:09 -05:00
Stefan Metzmacher
b08484d715 cifs: use mod_delayed_work() for &server->reconnect if already queued
mod_delayed_work() is safer than queue_delayed_work() if there's a
chance that the work is already in the queue.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-03-22 22:49:09 -05:00
Stefan Metzmacher
e2e87519bd cifs: call wake_up(&server->response_q) inside of cifs_reconnect()
This means it's consistently called and the callers don't need to
care about it.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-03-22 22:49:09 -05:00
Paulo Alcantara (SUSE)
bacd704a95 cifs: handle prefix paths in reconnect
For the case where we have a DFS path like below and we're currently
connected to targetA:

    //dfsroot/link -> //targetA/share/foo, //targetB/share/bar

after failover, we should make sure to update cifs_sb->prepath so the
next operations will use the new prefix path "/bar".

Besides, in order to simplify the use of different prefix paths,
enforce CIFS_MOUNT_USE_PREFIX_PATH for DFS mounts so we don't have to
revalidate the root dentry every time we set a new prefix path.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-03-22 22:49:09 -05:00
Steve French
ffdec8d642 cifs: do not ignore the SYNC flags in getattr
Check the AT_STATX_FORCE_SYNC flag and force an attribute
revalidation if requested by the caller, and if the caller
specificies AT_STATX_DONT_SYNC only revalidate cached attributes
if required.  In addition do not flush writes in getattr (which
can be expensive) if size or timestamps not requested by the
caller.

Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-03-22 22:49:09 -05:00
Linus Torvalds
cd607737f3 three small smb3 fixes, 2 for stable
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Merge tag '5.6-rc6-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs fixes from Steve French:
 "Three small smb3 fixes, two for stable"

* tag '5.6-rc6-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  CIFS: fiemap: do not return EINVAL if get nothing
  CIFS: Increment num_remote_opens stats counter even in case of smb2_query_dir_first
  cifs: potential unintitliazed error code in cifs_getattr()
2020-03-19 10:19:11 -07:00
Linus Torvalds
dcf23ac3e8 locks: reinstate locks_delete_block optimization
There is measurable performance impact in some synthetic tests due to
commit 6d390e4b5d (locks: fix a potential use-after-free problem when
wakeup a waiter). Fix the race condition instead by clearing the
fl_blocker pointer after the wake_up, using explicit acquire/release
semantics.

This does mean that we can no longer use the clearing of fl_blocker as
the wait condition, so switch the waiters over to checking whether the
fl_blocked_member list_head is empty.

Reviewed-by: yangerkun <yangerkun@huawei.com>
Reviewed-by: NeilBrown <neilb@suse.de>
Fixes: 6d390e4b5d (locks: fix a potential use-after-free problem when wakeup a waiter)
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-03-18 13:03:38 -07:00
Murphy Zhou
979a2665eb CIFS: fiemap: do not return EINVAL if get nothing
If we call fiemap on a truncated file with none blocks allocated,
it makes sense we get nothing from this call. No output means
no blocks have been counted, but the call succeeded. It's a valid
response.

Simple example reproducer:
xfs_io -f 'truncate 2M' -c 'fiemap -v' /cifssch/testfile
xfs_io: ioctl(FS_IOC_FIEMAP) ["/cifssch/testfile"]: Invalid argument

Signed-off-by: Murphy Zhou <jencce.kernel@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
CC: Stable <stable@vger.kernel.org>
2020-03-17 13:27:06 -05:00
Shyam Prasad N
1be1fa42eb CIFS: Increment num_remote_opens stats counter even in case of smb2_query_dir_first
The num_remote_opens counter keeps track of the number of open files which must be
maintained by the server at any point. This is a per-tree-connect counter, and the value
of this counter gets displayed in the /proc/fs/cifs/Stats output as a following...

Open files: 0 total (local), 1 open on server
                             ^^^^^^^^^^^^^^^^
As a thumb-rule, we want to increment this counter for each open/create that we
successfully execute on the server. Similarly, we should decrement the counter when
we successfully execute a close.

In this case, an increment was being missed in case of smb2_query_dir_first,
in case of successful open. As a result, we would underflow the counter and we
could even see the counter go to negative after sufficient smb2_query_dir_first calls.

I tested the stats counter for a bunch of filesystem operations with the fix.
And it looks like the counter looks correct to me.

I also check if we missed the increments and decrements elsewhere. It does not
seem so. Few other cases where an open is done and we don't increment the counter are
the compound calls where the corresponding close is also sent in the request.

Signed-off-by: Shyam Prasad N <nspmangalore@gmail.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2020-03-17 13:27:03 -05:00
Dan Carpenter
39946886fc cifs: potential unintitliazed error code in cifs_getattr()
Smatch complains that "rc" could be uninitialized.

    fs/cifs/inode.c:2206 cifs_getattr() error: uninitialized symbol 'rc'.

Changing it to "return 0;" improves readability as well.

Fixes: cc1baf98c8f6 ("cifs: do not ignore the SYNC flags in getattr")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
2020-03-17 13:26:26 -05:00
Linus Torvalds
807f030b44 Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs fixes from Al Viro:
 "A couple of fixes for old crap in ->atomic_open() instances"

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  cifs_atomic_open(): fix double-put on late allocation failure
  gfs2_atomic_open(): fix O_EXCL|O_CREAT handling on cold dcache
2020-03-12 15:51:26 -07:00
Al Viro
d9a9f4849f cifs_atomic_open(): fix double-put on late allocation failure
several iterations of ->atomic_open() calling conventions ago, we
used to need fput() if ->atomic_open() failed at some point after
successful finish_open().  Now (since 2016) it's not needed -
struct file carries enough state to make fput() work regardless
of the point in struct file lifecycle and discarding it on
failure exits in open() got unified.  Unfortunately, I'd missed
the fact that we had an instance of ->atomic_open() (cifs one)
that used to need that fput(), as well as the stale comment in
finish_open() demanding such late failure handling.  Trivially
fixed...

Fixes: fe9ec8291f "do_last(): take fput() on error after opening to out:"
Cc: stable@kernel.org # v4.7+
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-03-12 18:25:20 -04:00
Joe Perches
fb4b5f1346 cifs: Use #define in cifs_dbg
All other uses of cifs_dbg use defines so change this one.

Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-02-24 14:20:38 -06:00
Aurelien Aptel
86f740f2ae cifs: fix rename() by ensuring source handle opened with DELETE bit
To rename a file in SMB2 we open it with the DELETE access and do a
special SetInfo on it. If the handle is missing the DELETE bit the
server will fail the SetInfo with STATUS_ACCESS_DENIED.

We currently try to reuse any existing opened handle we have with
cifs_get_writable_path(). That function looks for handles with WRITE
access but doesn't check for DELETE, making rename() fail if it finds
a handle to reuse. Simple reproducer below.

To select handles with the DELETE bit, this patch adds a flag argument
to cifs_get_writable_path() and find_writable_file() and the existing
'bool fsuid_only' argument is converted to a flag.

The cifsFileInfo struct only stores the UNIX open mode but not the
original SMB access flags. Since the DELETE bit is not mapped in that
mode, this patch stores the access mask in cifs_fid on file open,
which is accessible from cifsFileInfo.

Simple reproducer:

	#include <stdio.h>
	#include <stdlib.h>
	#include <sys/types.h>
	#include <sys/stat.h>
	#include <fcntl.h>
	#include <unistd.h>
	#define E(s) perror(s), exit(1)

	int main(int argc, char *argv[])
	{
		int fd, ret;
		if (argc != 3) {
			fprintf(stderr, "Usage: %s A B\n"
			"create&open A in write mode, "
			"rename A to B, close A\n", argv[0]);
			return 0;
		}

		fd = openat(AT_FDCWD, argv[1], O_WRONLY|O_CREAT|O_SYNC, 0666);
		if (fd == -1) E("openat()");

		ret = rename(argv[1], argv[2]);
		if (ret) E("rename()");

		ret = close(fd);
		if (ret) E("close()");

		return ret;
	}

$ gcc -o bugrename bugrename.c
$ ./bugrename /mnt/a /mnt/b
rename(): Permission denied

Fixes: 8de9e86c67 ("cifs: create a helper to find a writeable handle by path name")
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
2020-02-24 14:20:38 -06:00
Steve French
ec57010acd cifs: add missing mount option to /proc/mounts
We were not displaying the mount option "signloosely" in /proc/mounts
for cifs mounts which some users found confusing recently

Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
2020-02-24 14:20:38 -06:00
Paulo Alcantara (SUSE)
1542552338 cifs: fix potential mismatch of UNC paths
Ensure that full_path is an UNC path that contains '\\' as delimiter,
which is required by cifs_build_devname().

The build_path_from_dentry_optional_prefix() function may return a
path with '/' as delimiter when using SMB1 UNIX extensions, for
example.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
2020-02-24 14:20:38 -06:00
Ronnie Sahlberg
fc513fac56 cifs: don't leak -EAGAIN for stat() during reconnect
If from cifs_revalidate_dentry_attr() the SMB2/QUERY_INFO call fails with an
error, such as STATUS_SESSION_EXPIRED, causing the session to be reconnected
it is possible we will leak -EAGAIN back to the application even for
system calls such as stat() where this is not a valid error.

Fix this by re-trying the operation from within cifs_revalidate_dentry_attr()
if cifs_get_inode_info*() returns -EAGAIN.

This fixes stat() and possibly also other system calls that uses
cifs_revalidate_dentry*().

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
CC: Stable <stable@vger.kernel.org>
2020-02-24 14:20:38 -06:00
Ronnie Sahlberg
85db6b7ae6 cifs: make sure we do not overflow the max EA buffer size
RHBZ: 1752437

Before we add a new EA we should check that this will not overflow
the maximum buffer we have available to read the EAs back.
Otherwise we can get into a situation where the EAs are so big that
we can not read them back to the client and thus we can not list EAs
anymore or delete them.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
2020-02-14 11:10:24 -06:00
Steve French
2c6251ad91 cifs: enable change notification for SMB2.1 dialect
It was originally enabled only for SMB3 or later dialects, but
had requests to add it to SMB2.1 mounts as well given the
large number of systems at that dialect level.

Signed-off-by: Steve French <stfrench@microsoft.com>
Reported-by: L Walsh <cifs@tlinx.org>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
2020-02-14 11:10:06 -06:00
Frank Sorenson
f52aa79df4 cifs: Fix mode output in debugging statements
A number of the debug statements output file or directory mode
in hex.  Change these to print using octal.

Signed-off-by: Frank Sorenson <sorenson@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-02-12 22:24:26 -06:00
Petr Pavlu
3f6166aaf1 cifs: fix mount option display for sec=krb5i
Fix display for sec=krb5i which was wrongly interleaved by cruid,
resulting in string "sec=krb5,cruid=<...>i" instead of
"sec=krb5i,cruid=<...>".

Fixes: 96281b9e46 ("smb3: for kerberos mounts display the credential uid used")
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-02-10 08:32:30 -06:00
Linus Torvalds
d1ea35f4cd 13 cifs/smb3 patches most from testing at the SMB3 plugfest this week
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Merge tag '5.6-rc-smb3-plugfest-patches' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs fixes from Steve French:
 "13 cifs/smb3 patches, most from testing at the SMB3 plugfest this week:

   - Important fix for multichannel and for modefromsid mounts.

   - Two reconnect fixes

   - Addition of SMB3 change notify support

   - Backup tools fix

   - A few additional minor debug improvements (tracepoints and
     additional logging found useful during testing this week)"

* tag '5.6-rc-smb3-plugfest-patches' of git://git.samba.org/sfrench/cifs-2.6:
  smb3: Add defines for new information level, FileIdInformation
  smb3: print warning once if posix context returned on open
  smb3: add one more dynamic tracepoint missing from strict fsync path
  cifs: fix mode bits from dir listing when mounted with modefromsid
  cifs: fix channel signing
  cifs: add SMB3 change notification support
  cifs: make multichannel warning more visible
  cifs: fix soft mounts hanging in the reconnect code
  cifs: Add tracepoints for errors on flush or fsync
  cifs: log warning message (once) if out of disk space
  cifs: fail i/o on soft mounts if sessionsetup errors out
  smb3: fix problem with null cifs super block with previous patch
  SMB3: Backup intent flag missing from some more ops
2020-02-09 13:27:17 -08:00
Steve French
51d92d69f7 smb3: Add defines for new information level, FileIdInformation
See MS-FSCC 2.4.43.  Valid to be quried from most
Windows servers (among others).

Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
2020-02-06 17:32:24 -06:00
Steve French
ab3459d8f0 smb3: print warning once if posix context returned on open
SMB3.1.1 POSIX Context processing is not complete yet - so print warning
(once) if server returns it on open.

Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
2020-02-06 17:31:56 -06:00
Steve French
2391ca41b4 smb3: add one more dynamic tracepoint missing from strict fsync path
We didn't have a dynamic trace point for catching errors in
file_write_and_wait_range error cases in cifs_strict_fsync.

Since not all apps check for write behind errors, it can be
important for debugging to be able to trace these error
paths.

Suggested-and-reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-02-06 17:21:23 -06:00
Aurelien Aptel
e3e056c351 cifs: fix mode bits from dir listing when mounted with modefromsid
When mounting with -o modefromsid, the mode bits are stored in an
ACE. Directory enumeration (e.g. ls -l /mnt) triggers an SMB Query Dir
which does not include ACEs in its response. The mode bits in this
case are silently set to a default value of 755 instead.

This patch marks the dentry created during the directory enumeration
as needing re-evaluation (i.e. additional Query Info with ACEs) so
that the mode bits can be properly extracted.

Quick repro:

$ mount.cifs //win19.test/data /mnt -o ...,modefromsid
$ touch /mnt/foo && chmod 751 /mnt/foo
$ stat /mnt/foo
  # reports 751 (OK)
$ sleep 2
  # dentry older than 1s by default get invalidated
$ ls -l /mnt
  # since dentry invalid, ls does a Query Dir
  # and reports foo as 755 (WRONG)

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2020-02-06 17:19:38 -06:00
Aurelien Aptel
cc95b67727 cifs: fix channel signing
The server var was accidentally used as an iterator over the global
list of connections, thus overwritten the passed argument. This
resulted in the wrong signing key being returned for extra channels.

Fix this by using a separate var to iterate.

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2020-02-06 12:42:36 -06:00
Steve French
d26c2ddd33 cifs: add SMB3 change notification support
A commonly used SMB3 feature is change notification, allowing an
app to be notified about changes to a directory. The SMB3
Notify request blocks until the server detects a change to that
directory or its contents that matches the completion flags
that were passed in and the "watch_tree" flag (which indicates
whether subdirectories under this directory should be also
included).  See MS-SMB2 2.2.35 for additional detail.

To use this simply pass in the following structure to ioctl:

 struct __attribute__((__packed__)) smb3_notify {
        uint32_t completion_filter;
        bool    watch_tree;
 } __packed;

 using CIFS_IOC_NOTIFY  0x4005cf09
 or equivalently _IOW(CIFS_IOCTL_MAGIC, 9, struct smb3_notify)

SMB3 change notification is supported by all major servers.
The ioctl will block until the server detects a change to that
directory or its subdirectories (if watch_tree is set).

Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Acked-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
2020-02-06 09:14:28 -06:00
Aurelien Aptel
343a1b777a cifs: make multichannel warning more visible
When no interfaces are returned by the server we cannot open multiple
channels. Make it more obvious by reporting that to the user at the
VFS log level.

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-02-06 09:12:16 -06:00