Commit Graph

479 Commits

Author SHA1 Message Date
Christian Brauner
c39c07fce7
cifs: use stub posix acl handlers
Now that cifs supports the get and set acl inode operations and the vfs
has been switched to the new posi api, cifs can simply rely on the stub
posix acl handlers. The custom xattr handlers and associated unused
helpers can be removed.

Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2022-10-20 10:13:32 +02:00
Christian Brauner
dc1af4c4b4
cifs: implement set acl method
The current way of setting and getting posix acls through the generic
xattr interface is error prone and type unsafe. The vfs needs to
interpret and fixup posix acls before storing or reporting it to
userspace. Various hacks exist to make this work. The code is hard to
understand and difficult to maintain in it's current form. Instead of
making this work by hacking posix acls through xattr handlers we are
building a dedicated posix acl api around the get and set inode
operations. This removes a lot of hackiness and makes the codepaths
easier to maintain. A lot of background can be found in [1].

In order to build a type safe posix api around get and set acl we need
all filesystem to implement get and set acl.

So far cifs wasn't able to implement get and set acl inode operations
because it needs access to the dentry. Now that we extended the set acl
inode operation to take a dentry argument and added a new get acl inode
operation that takes a dentry argument we can let cifs implement get and
set acl inode operations.

This is mostly a copy and paste of the codepaths currently used in cifs'
posix acl xattr handler. After we have fully implemented the posix acl
api and switched the vfs over to it, the cifs specific posix acl xattr
handler and associated code will be removed and the code duplication
will go away.

Note, until the vfs has been switched to the new posix acl api this
patch is a non-functional change.

Link: https://lore.kernel.org/all/20220801145520.1532837-1-brauner@kernel.org [1]
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2022-10-20 10:13:28 +02:00
Christian Brauner
bd9684b042
cifs: implement get acl method
The current way of setting and getting posix acls through the generic
xattr interface is error prone and type unsafe. The vfs needs to
interpret and fixup posix acls before storing or reporting it to
userspace. Various hacks exist to make this work. The code is hard to
understand and difficult to maintain in it's current form. Instead of
making this work by hacking posix acls through xattr handlers we are
building a dedicated posix acl api around the get and set inode
operations. This removes a lot of hackiness and makes the codepaths
easier to maintain. A lot of background can be found in [1].

In order to build a type safe posix api around get and set acl we need
all filesystem to implement get and set acl.

So far cifs wasn't able to implement get and set acl inode operations
because it needs access to the dentry. Now that we extended the set acl
inode operation to take a dentry argument and added a new get acl inode
operation that takes a dentry argument we can let cifs implement get and
set acl inode operations.

This is mostly a copy and paste of the codepaths currently used in cifs'
posix acl xattr handler. After we have fully implemented the posix acl
api and switched the vfs over to it, the cifs specific posix acl xattr
handler and associated code will be removed and the code duplication
will go away.

Note, until the vfs has been switched to the new posix acl api this
patch is a non-functional change.

Link: https://lore.kernel.org/all/20220801145520.1532837-1-brauner@kernel.org [1]
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2022-10-20 10:13:27 +02:00
Enzo Matsumiya
d7173623bf cifs: use ALIGN() and round_up() macros
Improve code readability by using existing macros:

Replace hardcoded alignment computations (e.g. (len + 7) & ~0x7) by
ALIGN()/IS_ALIGNED() macros.

Also replace (DIV_ROUND_UP(len, 8) * 8) with ALIGN(len, 8), which, if
not optimized by the compiler, has the overhead of a multiplication
and a division. Do the same for roundup() by replacing it by round_up()
(division-less version, but requires the multiple to be a power of 2,
which is always the case for us).

And remove some unnecessary checks where !IS_ALIGNED() would fit, but
calling round_up() directly is fine as it's a no-op if the value is
already aligned.

Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-10-13 09:36:39 -05:00
Gustavo A. R. Silva
943deb6066 cifs: Replace a couple of one-element arrays with flexible-array members
One-element arrays are deprecated, and we are replacing them with flexible
array members instead. So, replace one-element arrays with flexible-array
member in structs negotiate_req and extended_response, and refactor the
rest of the code, accordingly.

Also, make use of the DECLARE_FLEX_ARRAY() helper to declare flexible
array member EncryptionKey in union u. This new helper allows for
flexible-array members in unions.

Change pointer notation to proper array notation in a call to memcpy()
where flexible-array member DialectsArray is being used as destination
argument.

Important to mention is that doing a build before/after this patch results
in no binary output differences.

This helps with the ongoing efforts to tighten the FORTIFY_SOURCE
routines on memcpy() and help us make progress towards globally
enabling -fstrict-flex-arrays=3 [1].

Link: https://github.com/KSPP/linux/issues/79
Link: https://github.com/KSPP/linux/issues/229
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101836 [1]
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-10-05 17:42:38 -05:00
Enzo Matsumiya
70f08f914a cifs: remove useless DeleteMidQEntry()
DeleteMidQEntry() was just a proxy for cifs_mid_q_entry_release().

- remove DeleteMidQEntry()
- rename cifs_mid_q_entry_release() to release_mid()
- rename kref_put() callback _cifs_mid_q_entry_release to __release_mid
- rename AllocMidQEntry() to alloc_mid()
- rename cifs_delete_mid() to delete_mid()

Update callers to use new names.

Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-08-05 11:24:06 -05:00
Steve French
fb157ed226 cifs: when insecure legacy is disabled shrink amount of SMB1 code
Currently much of the smb1 code is built even when
CONFIG_CIFS_ALLOW_INSECURE_LEGACY is disabled.

Move cifssmb.c to only be compiled when insecure legacy is disabled,
and move various SMB1/CIFS helper functions to that ifdef.  Some
functions that were not SMB1/CIFS specific needed to be moved out of
cifssmb.c

This shrinks cifs.ko by more than 10% which is good - but also will
help with the eventual movement of the legacy code to a distinct
module.  Follow on patches can shrink the number of ifdefs by
code restructuring where smb1 code is wedged in functions that
should be calling dialect specific helper functions instead,
and also by moving some functions from file.c/dir.c/inode.c into
smb1 specific c files.

Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-08-05 11:24:03 -05:00
Shyam Prasad N
d7d7a66aac cifs: avoid use of global locks for high contention data
During analysis of multichannel perf, it was seen that
the global locks cifs_tcp_ses_lock and GlobalMid_Lock, which
were shared between various data structures were causing a
lot of contention points.

With this change, we're breaking down the use of these locks
by introducing new locks at more granular levels. i.e.
server->srv_lock, ses->ses_lock and tcon->tc_lock to protect
the unprotected fields of server, session and tcon structs;
and server->mid_lock to protect mid related lists and entries
at server level.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-08-01 01:34:45 -05:00
Colin Ian King
4da2cd0517 cifs: remove redundant initialization to variable mnt_sign_enabled
Variable mnt_sign_enabled is being initialized with a value that
is never read, it is being reassigned later on with a different
value. The initialization is redundant and can be removed.

Cleans up clang scan-build warning:
fs/cifs/cifssmb.c:465:7: warning: Value stored to 'mnt_sign_enabled
 during its initialization is never read

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-08-01 01:34:44 -05:00
Shyam Prasad N
dd3cd8709e cifs: use new enum for ses_status
ses->status today shares statusEnum with server->tcpStatus.
This has been confusing, and tcon->status has deviated to use
a new enum. Follow suit and use new enum for ses_status as well.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-05-24 14:11:17 -05:00
Paulo Alcantara
d80c69846d cifs: fix signed integer overflow when fl_end is OFFSET_MAX
This fixes the following when running xfstests generic/504:

[  134.394698] CIFS: Attempting to mount \\win16.vm.test\Share
[  134.420905] CIFS: VFS: generate_smb3signingkey: dumping generated
AES session keys
[  134.420911] CIFS: VFS: Session Id    05 00 00 00 00 c4 00 00
[  134.420914] CIFS: VFS: Cipher type   1
[  134.420917] CIFS: VFS: Session Key   ea 0b d9 22 2e af 01 69 30 1b
15 74 bf 87 41 11
[  134.420920] CIFS: VFS: Signing Key   59 28 43 5c f0 b6 b1 6f f5 7b
65 f2 9f 9e 58 7d
[  134.420923] CIFS: VFS: ServerIn Key  eb aa 58 c8 95 01 9a f7 91 98
e4 fa bc d8 74 f1
[  134.420926] CIFS: VFS: ServerOut Key 08 5b 21 e5 2e 4e 86 f6 05 c2
58 e0 af 53 83 e7
[  134.771946]
================================================================================
[  134.771953] UBSAN: signed-integer-overflow in fs/cifs/file.c:1706:19
[  134.771957] 9223372036854775807 + 1 cannot be represented in type
'long long int'
[  134.771960] CPU: 4 PID: 2773 Comm: flock Not tainted 5.11.22 #1
[  134.771964] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
[  134.771966] Call Trace:
[  134.771970]  dump_stack+0x8d/0xb5
[  134.771981]  ubsan_epilogue+0x5/0x50
[  134.771988]  handle_overflow+0xa3/0xb0
[  134.771997]  ? lockdep_hardirqs_on_prepare+0xe8/0x1b0
[  134.772006]  cifs_setlk+0x63c/0x680 [cifs]
[  134.772085]  ? _get_xid+0x5f/0xa0 [cifs]
[  134.772085]  cifs_flock+0x131/0x400 [cifs]
[  134.772085]  __x64_sys_flock+0xfc/0x120
[  134.772085]  do_syscall_64+0x33/0x40
[  134.772085]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[  134.772085] RIP: 0033:0x7fea4f83b3fb
[  134.772085] Code: ff 48 8b 15 8f 1a 0d 00 f7 d8 64 89 02 b8 ff ff
ff ff eb da e8 16 0b 02 00 66 0f 1f 44 00 00 f3 0f 1e fa b8 49 00 00
00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 5d 1a 0d 00 f7 d8 64 89
01 48

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-05-19 10:54:41 -05:00
Linus Torvalds
9a005bea4f 14 fixes to cifs client and to smbfs_common code
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Merge tag '5.18-smb3-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6

Pull more cifs updates from Steve French:

 - three fixes for big endian issues in how Persistent and Volatile file
   ids were stored

 - Various misc. fixes: including some for oops, 2 for ioctls, 1 for
   writeback

 - cleanup of how tcon (tree connection) status is tracked

 - Four changesets to move various duplicated protocol definitions
   (defined both in cifs.ko and ksmbd) into smbfs_common/smb2pdu.h

 - important performance improvement to use cached handles in some key
   compounding code paths (reduces numbers of opens/closes sent in some
   workloads)

 - fix to allow alternate DFS target to be used to retry on a failed i/o

* tag '5.18-smb3-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: fix NULL ptr dereference in smb2_ioctl_query_info()
  cifs: prevent bad output lengths in smb2_ioctl_query_info()
  smb3: fix ksmbd bigendian bug in oplock break, and move its struct to smbfs_common
  smb3: cleanup and clarify status of tree connections
  smb3: move defines for query info and query fsinfo to smbfs_common
  smb3: move defines for ioctl protocol header and SMB2 sizes to smbfs_common
  [smb3] move more common protocol header definitions to smbfs_common
  cifs: fix incorrect use of list iterator after the loop
  ksmbd: store fids as opaque u64 integers
  cifs: fix bad fids sent over wire
  cifs: change smb2_query_info_compound to use a cached fid, if available
  cifs: convert the path to utf16 in smb2_query_info_compound
  cifs: writeback fix
  cifs: do not skip link targets when an I/O fails
2022-04-01 14:31:57 -07:00
Matthew Wilcox (Oracle)
704528d895 fs: Remove ->readpages address space operation
All filesystems have now been converted to use ->readahead, so
remove the ->readpages operation and fix all the comments that
used to refer to it.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
2022-04-01 13:45:33 -04:00
Steve French
fdf59eb548 smb3: cleanup and clarify status of tree connections
Currently the way the tid (tree connection) status is tracked
is confusing.  The same enum is used for structs cifs_tcon
and cifs_ses and TCP_Server_info, but each of these three has
different states that they transition among.  The current
code also unnecessarily uses camelCase.

Convert from use of statusEnum to a new tid_status_enum for
tree connections.  The valid states for a tid are:

        TID_NEW = 0,
        TID_GOOD,
        TID_EXITING,
        TID_NEED_RECON,
        TID_NEED_TCON,
        TID_IN_TCON,
        TID_NEED_FILES_INVALIDATE, /* unused, considering removing in future */
        TID_IN_FILES_INVALIDATE

It also removes CifsNeedTcon, CifsInTcon, CifsNeedFilesInvalidate and
CifsInFilesInvalidate from the statusEnum used for session and
TCP_Server_Info since they are not relevant for those.

A follow on patch will fix the places where we use the
tcon->need_reconnect flag to be more consistent with the tid->status.

Also fixes a bug that was:
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-03-28 17:07:30 -05:00
Shyam Prasad N
73f9bfbe3d cifs: maintain a state machine for tcp/smb/tcon sessions
If functions like cifs_negotiate_protocol, cifs_setup_session,
cifs_tree_connect are called in parallel on different channels,
each of these will be execute the requests. This maybe unnecessary
in some cases, and only the first caller may need to do the work.

This is achieved by having more states for the tcp/smb/tcon session
status fields. And tracking the state of reconnection based on the
state machine.

For example:
for tcp connections:
CifsNew/CifsNeedReconnect ->
  CifsNeedNegotiate ->
    CifsInNegotiate ->
      CifsNeedSessSetup ->
        CifsInSessSetup ->
          CifsGood

for smb sessions:
CifsNew/CifsNeedReconnect ->
  CifsGood

for tcon:
CifsNew/CifsNeedReconnect ->
  CifsInFilesInvalidate ->
    CifsNeedTcon ->
      CifsInTcon ->
        CifsGood

If any channel reconnect sees that it's in the middle of
transition to CifsGood, then they can skip the function.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-01-07 20:09:22 -06:00
Shyam Prasad N
080dc5e565 cifs: take cifs_tcp_ses_lock for status checks
While checking/updating status for tcp ses, smb ses or tcon,
we take GlobalMid_Lock. This doesn't make any sense.
Replaced it with cifs_tcp_ses_lock.

Ideally, we should take a spin lock per struct.
But since tcp ses, smb ses and tcon objects won't add up to a lot,
I think there should not be too much contention.

Also, in few other places, these are checked without locking.
Added locking for these.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-01-07 20:07:07 -06:00
Shyam Prasad N
183eea2ee5 cifs: reconnect only the connection and not smb session where possible
With the new per-channel bitmask for reconnect, we have an option to
reconnect the tcp session associated with the channel without reconnecting
the smb session. i.e. if there are still channels to operate on, we can
continue to use the smb session and tcon.

However, there are cases where it makes sense to reconnect the smb session
even when there are active channels underneath. For example for
SMB session expiry.

With this patch, we'll have an option to do either, and use the correct
option for specific cases.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-01-02 20:38:46 -06:00
Shyam Prasad N
f486ef8e20 cifs: use the chans_need_reconnect bitmap for reconnect status
We use the concept of "binding" when one of the secondary channel
is in the process of connecting/reconnecting to the server. Till this
binding process completes, and the channel is bound to an existing session,
we redirect traffic from other established channels on the binding channel,
effectively blocking all traffic till individual channels get reconnected.

With my last set of commits, we can get rid of this binding serialization.
We now have a bitmap of connection states for each channel. We will use
this bitmap instead for tracking channel status.

Having a bitmap also now enables us to keep the session alive, as long
as even a single channel underneath is alive.

Unfortunately, this also meant that we need to supply the tcp connection
info for the channel during all negotiate and session setup functions.
These changes have resulted in a slightly bigger code churn.
However, I expect perf and robustness improvements in the mchan scenario
after this change.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-01-02 20:38:46 -06:00
Shyam Prasad N
d1a931ce2e cifs: track individual channel status using chans_need_reconnect
We needed a way to identify the channels under the smb session
which are in reconnect, so that the traffic to other channels
can continue. So I replaced the bool need_reconnect with
a bitmask identifying all the channels that need reconnection
(named chans_need_reconnect). When a channel needs reconnection,
the bit corresponding to the index of the server in ses->chans
is used to set this bitmask. Checking if no channels or all
the channels need reconnect then becomes very easy.

Also wrote some helper macros for checking and setting the bits.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-01-02 20:38:46 -06:00
Steve French
099dd788e3 cifs: remove pathname for file from SPDX header
checkpatch complains about source files with filenames (e.g. in
these cases just below the SPDX header in comments at the top of
various files in fs/cifs). It also is helpful to change this now
so will be less confusing when the parent directory is renamed
e.g. from fs/cifs to fs/smb_client (or fs/smbfs)

Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-09-13 14:51:10 -05:00
Ronnie Sahlberg
76a3c92ec9 cifs: remove support for NTLM and weaker authentication algorithms
for SMB1.
This removes the dependency to DES.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-08-25 15:47:06 -05:00
Shyam Prasad N
18d04062f8 cifs: enable fscache usage even for files opened as rw
So far, the fscache implementation we had supports only
a small set of use cases. Particularly for files opened
with O_RDONLY.

This commit enables it even for rw based file opens. It
also enables the reuse of cached data in case of mount
option (cache=singleclient) where it is guaranteed that
this is the only client (and server) which operates on
the files. There's also a single line change in fscache.c
to get around a bug seen in fscache.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-08-25 15:45:10 -05:00
Steve French
7b09d4e0be CIFS: Clarify SMB1 code for POSIX delete file
Coverity also complains about the way we calculate the offset
(starting from the address of a 4 byte array within the
header structure rather than from the beginning of the struct
plus 4 bytes) for SMB1 CIFSPOSIXDelFile. This changeset
doesn't change the address but makes it slightly clearer.

Addresses-Coverity: 711519 ("Out of bounds write")
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-07-22 14:35:15 -05:00
Steve French
21a6491099 CIFS: Clarify SMB1 code for POSIX Create
Coverity also complains about the way we calculate the offset
(starting from the address of a 4 byte array within the
header structure rather than from the beginning of the struct
plus 4 bytes) for SMB1 CIFSPOSIXCreate. This changeset
doesn't change the address but makes it slightly clearer.

Addresses-Coverity: 711518 ("Out of bounds write")
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-07-22 13:50:41 -05:00
Steve French
d4dc277c48 CIFS: Clarify SMB1 code for POSIX Lock
Coverity also complains about the way we calculate the offset
(starting from the address of a 4 byte array within the
header structure rather than from the beginning of the struct
plus 4 bytes) for SMB1 PosixLock. This changeset
doesn't change the address but makes it slightly clearer.

Addresses-Coverity: 711520 ("Out of bounds write")
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-07-07 16:43:17 -05:00
Steve French
f371793d6e CIFS: Clarify SMB1 code for rename open file
Coverity also complains about the way we calculate the offset
(starting from the address of a 4 byte array within the
header structure rather than from the beginning of the struct
plus 4 bytes) for SMB1 RenameOpenFile. This changeset
doesn't change the address but makes it slightly clearer.

Addresses-Coverity: 711521 ("Out of bounds write")
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-07-07 16:42:25 -05:00
Steve French
2a780e8b64 CIFS: Clarify SMB1 code for delete
Coverity also complains about the way we calculate the offset
(starting from the address of a 4 byte array within the
header structure rather than from the beginning of the struct
plus 4 bytes) for SMB1 SetFileDisposition (which is used to
unlink a file by setting the delete on close flag).  This
changeset doesn't change the address but makes it slightly
clearer.

Addresses-Coverity: 711524 ("Out of bounds write")
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-07-07 11:53:17 -05:00
Steve French
e3973ea3a7 CIFS: Clarify SMB1 code for SetFileSize
Coverity also complains about the way we calculate the offset
(starting from the address of a 4 byte array within the header
structure rather than from the beginning of the struct plus
4 bytes) for setting the file size using SMB1. This changeset
doesn't change the address but makes it slightly clearer.

Addresses-Coverity: 711525 ("Out of bounds write")
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-07-07 11:52:53 -05:00
Steve French
b019e1187c CIFS: Clarify SMB1 code for UnixSetPathInfo
Coverity also complains about the way we calculate the offset
(starting from the address of a 4 byte array within the
header structure rather than from the beginning of the struct
plus 4 bytes) for doing SetPathInfo (setattr) when using the Unix
extensions.  This doesn't change the address but makes it
slightly clearer.

Addresses-Coverity: 711528 ("Out of bounds read")
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-07-02 18:36:26 -05:00
Steve French
ded2d99cef CIFS: Clarify SMB1 code for UnixCreateSymLink
Coverity also complains about the way we calculate the offset
(starting from the address of a 4 byte array within the
header structure rather than from the beginning of the struct
plus 4 bytes) for creating SMB1 symlinks when using the Unix
extensions.  This doesn't change the address but
makes it slightly clearer.

Addresses-Coverity: 711530 ("Out of bounds read")
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-07-02 18:36:24 -05:00
Steve French
819f916c83 cifs: clarify SMB1 code for UnixCreateHardLink
Coverity complains about the way we calculate the offset
(starting from the address of a 4 byte array within the
header structure rather than from the beginning of the struct
plus 4 bytes).  This doesn't change the address but
makes it slightly clearer.

Addresses-Coverity: 711529 ("Out of bounds read")
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-07-02 18:36:23 -05:00
Steve French
929be906fa cifs: use SPDX-Licence-Identifier
Add SPDX license identifier and replace license boilerplate.
Corrects various checkpatch errors with the older format for
noting the LGPL license.

Signed-off-by: Steve French <stfrench@microsoft.com>
2021-06-20 21:28:17 -05:00
Colin Ian King
032e091d3e cifs: remove redundant initialization of variable rc
The variable rc is being initialized with a value that is never read, the
assignment is redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-06-20 21:28:16 -05:00
Ronnie Sahlberg
45c0f1aabe cifs: rename the *_shroot* functions to *_cached_dir*
These functions will eventually be used to cache any directory, not just the root
so change the names.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-04-25 16:28:23 -05:00
Aurelien Aptel
ec4e4862a9 cifs: remove old dead code
While reviewing a patch clarifying locks and locking hierarchy I
realized some locks were unused.

This commit removes old data and code that isn't actually used
anywhere, or hidden in ifdefs which cannot be enabled from the kernel
config.

* The uid/gid trees and associated locks are left-overs from when
  uid/sid mapping had an extra caching layer on top of the keyring and
  are now unused.
  See commit faa65f07d2 ("cifs: simplify id_to_sid and sid_to_id mapping code")
  from 2012.

* cifs_oplock_break_ops is a left-over from when slow_work was remplaced
  by regular workqueue and is now unused.
  See commit 9b64697246 ("cifs: use workqueue instead of slow-work")
  from 2010.

* CIFSSMBSetAttrLegacy is SMB1 cruft dealing with some legacy
  NT4/Win9x behaviour.

* Remove CONFIG_CIFS_DNOTIFY_EXPERIMENTAL left-overs. This was already
  partially removed in 392e1c5dc9 ("cifs: rename and clarify CIFS_ASYNC_OP and CIFS_NO_RESP")
  from 2019. Kill it completely.

* Another candidate that was considered but spared is
  CONFIG_CIFS_NFSD_EXPORT which has an empty implementation and cannot
  be enabled by a config option (although it is listed but disabled with
  "BROKEN" as a dep). It's unclear whether this could even function
  today in its current form but it has it's own .c file and Kconfig
  entry which is a bit more involved to remove and might make a come
  back?

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-04-25 16:28:22 -05:00
David Howells
cf0604a686 cifs: use discard iterator to discard unneeded network data more efficiently
The iterator, ITER_DISCARD, that can only be used in READ mode and
just discards any data copied to it, was added to allow a network
filesystem to discard any unwanted data sent by a server.
Convert cifs_discard_from_socket() to use this.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-02-25 19:08:06 -06:00
Gustavo A. R. Silva
df561f6688 treewide: Use fallthrough pseudo-keyword
Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-23 17:36:59 -05:00
Stefan Metzmacher
565674d613 cifs: merge __{cifs,smb2}_reconnect[_tcon]() into cifs_tree_connect()
They were identical execpt to CIFSTCon() vs. SMB2_tcon().
These are also available via ops->tree_connect().

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-08-02 18:00:26 -05:00
Ronnie Sahlberg
8e408fc9fd cifs: smb1: Try failing back to SetFileInfo if SetPathInfo fails
RHBZ 1145308

Some very old server may not support SetPathInfo to adjust the timestamps
of directories. For these servers, try to open the directory and use SetFileInfo.

Minor correction to patch included that was
Reported-by: kernel test robot <lkp@intel.com>

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Tested-by: Kenneth D'souza <kdsouza@redhat.com>
2020-08-02 18:00:25 -05:00
Steve French
adbb2dafe7 cifs: minor fix to two debug messages
Joe Perches pointed out that we were missing a newline
at the end of two debug messages

Reported-by: Joe Perches <joe@perches.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-06-01 00:10:18 -05:00
Joe Perches
a0a3036b81 cifs: Standardize logging output
Use pr_fmt to standardize all logging for fs/cifs.

Some logging output had no CIFS: specific prefix.

Now all output has one of three prefixes:

o CIFS:
o CIFS: VFS:
o Root-CIFS:

Miscellanea:

o Convert printks to pr_<level>
o Neaten macro definitions
o Remove embedded CIFS: prefixes from formats
o Convert "illegal" to "invalid"
o Coalesce formats
o Add missing '\n' format terminations
o Consolidate multiple cifs_dbg continuations into single calls
o More consistent use of upper case first word output logging
o Multiline statement argument alignment and wrapping

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-06-01 00:10:18 -05:00
Paulo Alcantara
e4af35fa55 cifs: handle hostnames that resolve to same ip in failover
In order to support reconnect to hostnames that resolve to same ip
address, besides relying on the currently set hostname to match DFS
targets, attempt to resolve the targets and then match their addresses
with the reconnected server ip address.

For instance, if we have two hostnames "FOO" and "BAR", and both
resolve to the same ip address, we would be able to handle failover in
DFS paths like

    \\FOO\dfs\link1 -> [ \BAZ\share2 (*), \BAR\share1 ]
    \\FOO\dfs\link2 -> [ \BAZ\share2 (*), \FOO\share1 ]

so when "BAZ" is no longer accessible, link1 and link2 would get
reconnected despite having different target hostnames.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-06-01 00:10:18 -05:00
Colin Ian King
136a5dc330 cifs: remove redundant initialization of variable rc
The variable rc is being initialized with a value that is never read
and it is being updated later with a new value.  The initialization is
redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-06-01 00:10:18 -05:00
Adam McCoy
a481379960 cifs: fix leaked reference on requeued write
Failed async writes that are requeued may not clean up a refcount
on the file, which can result in a leaked open. This scenario arises
very reliably when using persistent handles and a reconnect occurs
while writing.

cifs_writev_requeue only releases the reference if the write fails
(rc != 0). The server->ops->async_writev operation will take its own
reference, so the initial reference can always be released.

Signed-off-by: Adam McCoy <adam@forsedomani.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2020-05-14 17:47:01 -05:00
Jones Syue
1f641d9410 cifs: improve read performance for page size 64KB & cache=strict & vers=2.1+
Found a read performance issue when linux kernel page size is 64KB.
If linux kernel page size is 64KB and mount options cache=strict &
vers=2.1+, it does not support cifs_readpages(). Instead, it is using
cifs_readpage() and cifs_read() with maximum read IO size 16KB, which is
much slower than read IO size 1MB when negotiated SMB 2.1+. Since modern
SMB server supported SMB 2.1+ and Max Read Size can reach more than 64KB
(for example 1MB ~ 8MB), this patch check max_read instead of maxBuf to
determine whether server support readpages() and improve read performance
for page size 64KB & cache=strict & vers=2.1+, and for SMB1 it is more
cleaner to initialize server->max_read to server->maxBuf.

The client is a linux box with linux kernel 4.2.8,
page size 64KB (CONFIG_ARM64_64K_PAGES=y),
cpu arm 1.7GHz, and use mount.cifs as smb client.
The server is another linux box with linux kernel 4.2.8,
share a file '10G.img' with size 10GB,
and use samba-4.7.12 as smb server.

The client mount a share from the server with different
cache options: cache=strict and cache=none,
mount -tcifs //<server_ip>/Public /cache_strict -overs=3.0,cache=strict,username=<xxx>,password=<yyy>
mount -tcifs //<server_ip>/Public /cache_none -overs=3.0,cache=none,username=<xxx>,password=<yyy>

The client download a 10GbE file from the server across 1GbE network,
dd if=/cache_strict/10G.img of=/dev/null bs=1M count=10240
dd if=/cache_none/10G.img of=/dev/null bs=1M count=10240

Found that cache=strict (without patch) is slower read throughput and
smaller read IO size than cache=none.
cache=strict (without patch): read throughput 40MB/s, read IO size is 16KB
cache=strict (with patch): read throughput 113MB/s, read IO size is 1MB
cache=none: read throughput 109MB/s, read IO size is 1MB

Looks like if page size is 64KB,
cifs_set_ops() would use cifs_addr_ops_smallbuf instead of cifs_addr_ops,

	/* check if server can support readpages */
	if (cifs_sb_master_tcon(cifs_sb)->ses->server->maxBuf <
			PAGE_SIZE + MAX_CIFS_HDR_SIZE)
		inode->i_data.a_ops = &cifs_addr_ops_smallbuf;
	else
		inode->i_data.a_ops = &cifs_addr_ops;

maxBuf is came from 2 places, SMB2_negotiate() and CIFSSMBNegotiate(),
(SMB2_MAX_BUFFER_SIZE is 64KB)
SMB2_negotiate():
	/* set it to the maximum buffer size value we can send with 1 credit */
	server->maxBuf = min_t(unsigned int, le32_to_cpu(rsp->MaxTransactSize),
			       SMB2_MAX_BUFFER_SIZE);
CIFSSMBNegotiate():
	server->maxBuf = le32_to_cpu(pSMBr->MaxBufferSize);

Page size 64KB and cache=strict lead to read_pages() use cifs_readpage()
instead of cifs_readpages(), and then cifs_read() using maximum read IO
size 16KB, which is much slower than maximum read IO size 1MB.
(CIFSMaxBufSize is 16KB by default)

	/* FIXME: set up handlers for larger reads and/or convert to async */
	rsize = min_t(unsigned int, cifs_sb->rsize, CIFSMaxBufSize);
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Jones Syue <jonessyue@qnap.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-04-15 21:15:11 -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
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
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
Ronnie Sahlberg
09c40b1535 cifs: fix soft mounts hanging in the reconnect code
RHBZ: 1795423

This is the SMB1 version of a patch we already have for SMB2

In recent DFS updates we have a new variable controlling how many times we will
retry to reconnect the share.
If DFS is not used, then this variable is initialized to 0 in:

static inline int
dfs_cache_get_nr_tgts(const struct dfs_cache_tgt_list *tl)
{
        return tl ? tl->tl_numtgts : 0;
}

This means that in the reconnect loop in smb2_reconnect() we will immediately wrap retries to -1
and never actually get to pass this conditional:

                if (--retries)
                        continue;

The effect is that we no longer reach the point where we fail the commands with -EHOSTDOWN
and basically the kernel threads are virtually hung and unkillable.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
2020-02-06 09:12:00 -06:00