Commit Graph

59921 Commits

Author SHA1 Message Date
Steve French
3e7a02d478 smb3: allow disabling requesting leases
In some cases to work around server bugs or performance
problems it can be helpful to be able to disable requesting
SMB2.1/SMB3 leases on a particular mount (not to all servers
and all shares we are mounted to). Add new mount parm
"nolease" which turns off requesting leases on directory
or file opens.  Currently the only way to disable leases is
globally through a module load parameter. This is more
granular.

Suggested-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
CC: Stable <stable@vger.kernel.org>
2019-09-16 11:43:38 -05:00
Steve French
7dcc82c2df smb3: improve handling of share deleted (and share recreated)
When a share is deleted, returning EIO is confusing and no useful
information is logged.  Improve the handling of this case by
at least logging a better error for this (and also mapping the error
differently to EREMCHG).  See e.g. the new messages that would be logged:

[55243.639530] server share \\192.168.1.219\scratch deleted
[55243.642568] CIFS VFS: \\192.168.1.219\scratch BAD_NETWORK_NAME: \\192.168.1.219\scratch

In addition for the case where a share is deleted and then recreated
with the same name, have now fixed that so it works. This is sometimes
done for example, because the admin had to move a share to a different,
bigger local drive when a share is running low on space.

Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
2019-09-16 11:43:38 -05:00
Steve French
1b63f1840e smb3: display max smb3 requests in flight at any one time
Displayed in /proc/fs/cifs/Stats once for each
socket we are connected to.

This allows us to find out what the maximum number of
requests that had been in flight (at any one time). Note that
/proc/fs/cifs/Stats can be reset if you want to look for
maximum over a small period of time.

Sample output (immediately after mount):

Resources in use
CIFS Session: 1
Share (unique mount targets): 2
SMB Request/Response Buffer: 1 Pool size: 5
SMB Small Req/Resp Buffer: 1 Pool size: 30
Operations (MIDs): 0

0 session 0 share reconnects
Total vfs operations: 5 maximum at one time: 2

Max requests in flight: 2
1) \\localhost\scratch
SMBs: 18
Bytes read: 0  Bytes written: 0
...

Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2019-09-16 11:43:38 -05:00
Steve French
10328c44cc smb3: only offload decryption of read responses if multiple requests
No point in offloading read decryption if no other requests on the
wire

Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
2019-09-16 11:43:38 -05:00
Ronnie Sahlberg
496902dc17 cifs: add a helper to find an existing readable handle to a file
and convert smb2_query_path_info() to use it.
This will eliminate the need for a SMB2_Create when we already have an
open handle that can be used. This will also prevent a oplock break
in case the other handle holds a lease.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-09-16 11:43:38 -05:00
Steve French
563317ec30 smb3: enable offload of decryption of large reads via mount option
Disable offload of the decryption of encrypted read responses
by default (equivalent to setting this new mount option "esize=0").

Allow setting the minimum encrypted read response size that we
will choose to offload to a worker thread - it is now configurable
via on a new mount option "esize="

Depending on which encryption mechanism (GCM vs. CCM) and
the number of reads that will be issued in parallel and the
performance of the network and CPU on the client, it may make
sense to enable this since it can provide substantial benefit when
multiple large reads are in flight at the same time.

Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
2019-09-16 11:43:38 -05:00
Steve French
35cf94a397 smb3: allow parallelizing decryption of reads
decrypting large reads on encrypted shares can be slow (e.g. adding
multiple milliseconds per-read on non-GCM capable servers or
when mounting with dialects prior to SMB3.1.1) - allow parallelizing
of read decryption by launching worker threads.

Testing to Samba on localhost showed 25% improvement.
Testing to remote server showed very large improvement when
doing more than one 'cp' command was called at one time.

Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
2019-09-16 11:43:38 -05:00
Ronnie Sahlberg
3175eb9b57 cifs: add a debug macro that prints \\server\share for errors
Where we have a tcon available we can log \\server\share as part
of the message. Only do this for the VFS log level.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-09-16 11:43:38 -05:00
Steve French
46f17d1768 smb3: fix signing verification of large reads
Code cleanup in the 5.1 kernel changed the array
passed into signing verification on large reads leading
to warning messages being logged when copying files to local
systems from remote.

   SMB signature verification returned error = -5

This changeset fixes verification of SMB3 signatures of large
reads.

Suggested-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
2019-09-16 11:43:38 -05:00
Steve French
4f5c10f1ad smb3: allow skipping signature verification for perf sensitive configurations
Add new mount option "signloosely" which enables signing but skips the
sometimes expensive signing checks in the responses (signatures are
calculated and sent correctly in the SMB2/SMB3 requests even with this
mount option but skipped in the responses).  Although weaker for security
(and also data integrity in case a packet were corrupted), this can provide
enough of a performance benefit (calculating the signature to verify a
packet can be expensive especially for large packets) to be useful in
some cases.

Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
2019-09-16 11:43:38 -05:00
Steve French
f90f979726 smb3: add dynamic tracepoints for flush and close
We only had dynamic tracepoints on errors in flush
and close, but may be helpful to trace enter
and non-error exits for those.  Sample trace examples
(excerpts) from "cp" and "dd" show two of the new
tracepoints.

  cp-22823 [002] .... 123439.179701: smb3_enter: _cifsFileInfo_put: xid=10
  cp-22823 [002] .... 123439.179705: smb3_close_enter: xid=10 sid=0x98871327 tid=0xfcd585ff fid=0xc7f84682
  cp-22823 [002] .... 123439.179711: smb3_cmd_enter: sid=0x98871327 tid=0xfcd585ff cmd=6 mid=43
  cp-22823 [002] .... 123439.180175: smb3_cmd_done: sid=0x98871327 tid=0xfcd585ff cmd=6 mid=43
  cp-22823 [002] .... 123439.180179: smb3_close_done: xid=10 sid=0x98871327 tid=0xfcd585ff fid=0xc7f84682

  dd-22981 [003] .... 123696.946011: smb3_flush_enter: xid=24 sid=0x98871327 tid=0xfcd585ff fid=0x1917736f
  dd-22981 [003] .... 123696.946013: smb3_cmd_enter: sid=0x98871327 tid=0xfcd585ff cmd=7 mid=123
  dd-22981 [003] .... 123696.956639: smb3_cmd_done: sid=0x98871327 tid=0x0 cmd=7 mid=123
  dd-22981 [003] .... 123696.956644: smb3_flush_done: xid=24 sid=0x98871327 tid=0xfcd585ff fid=0x1917736f

Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
2019-09-16 11:43:38 -05:00
Steve French
cae53f70f8 smb3: log warning if CSC policy conflicts with cache mount option
If the server config (e.g. Samba smb.conf "csc policy = disable)
for the share indicates that the share should not be cached, log
a warning message if forced client side caching ("cache=ro" or
"cache=singleclient") is requested on mount.

Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
2019-09-16 11:43:38 -05:00
Steve French
41e033fecd smb3: add mount option to allow RW caching of share accessed by only 1 client
If a share is known to be only to be accessed by one client, we
can aggressively cache writes not just reads to it.

Add "cache=" option (cache=singleclient) for mounting read write shares
(that will not be read or written to from other clients while we have
it mounted) in order to improve performance.

Signed-off-by: Steve French <stfrench@microsoft.com>
2019-09-16 11:43:38 -05:00
Steve French
1981ebaabd smb3: add some more descriptive messages about share when mounting cache=ro
Add some additional logging so the user can see if the share they
mounted with cache=ro is considered read only by the server

CIFS: Attempting to mount //localhost/test
CIFS VFS: mounting share with read only caching. Ensure that the share will not be modified while in use.
CIFS VFS: read only mount of RW share

CIFS: Attempting to mount //localhost/test-ro
CIFS VFS: mounting share with read only caching. Ensure that the share will not be modified while in use.
CIFS VFS: mounted to read only share

Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
2019-09-16 11:43:37 -05:00
Steve French
83bbfa706d smb3: add mount option to allow forced caching of read only share
If a share is immutable (at least for the period that it will
be mounted) it would be helpful to not have to revalidate
dentries repeatedly that we know can not be changed remotely.

Add "cache=" option (cache=ro) for mounting read only shares
in order to improve performance in cases in which we know that
the share will not be changing while it is in use.

Signed-off-by: Steve French <stfrench@microsoft.com>
2019-09-16 11:43:37 -05:00
Colin Ian King
ac6ad7a8c9 cifs: fix dereference on ses before it is null checked
The assignment of pointer server dereferences pointer ses, however,
this dereference occurs before ses is null checked and hence we
have a potential null pointer dereference.  Fix this by only
dereferencing ses after it has been null checked.

Addresses-Coverity: ("Dereference before null check")
Fixes: 2808c6639104 ("cifs: add new debugging macro cifs_server_dbg")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-09-16 11:43:37 -05:00
Ronnie Sahlberg
afe6f65353 cifs: add new debugging macro cifs_server_dbg
which can be used from contexts where we have a TCP_Server_Info *server.
This new macro will prepend the debugging string with "Server:<servername> "
which will help when debugging issues on hosts with many cifs connections
to several different servers.

Convert a bunch of cifs_dbg(VFS) calls to cifs_server_dbg(VFS)

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-09-16 11:43:37 -05:00
Ronnie Sahlberg
dc9300a670 cifs: use existing handle for compound_op(OP_SET_INFO) when possible
If we already have a writable handle for a path we want to set the
attributes for then use that instead of a create/set-info/close compound.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-09-16 11:43:37 -05:00
Ronnie Sahlberg
8de9e86c67 cifs: create a helper to find a writeable handle by path name
rename() takes a path for old_file and in SMB2 we used to just create
a compound for create(old_path)/rename/close().
If we already have a writable handle we can avoid the create() and close()
altogether and just use the existing handle.

For this situation, as we avoid doing the create()
we also avoid triggering an oplock break for the existing handle.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-09-16 11:43:37 -05:00
YueHaibing
31ebdc1134 cifs: remove set but not used variables
Fixes gcc '-Wunused-but-set-variable' warning:

fs/cifs/file.c: In function cifs_lock:
fs/cifs/file.c:1696:24: warning: variable cinode set but not used [-Wunused-but-set-variable]
fs/cifs/file.c: In function cifs_write:
fs/cifs/file.c:1765:23: warning: variable cifs_sb set but not used [-Wunused-but-set-variable]
fs/cifs/file.c: In function collect_uncached_read_data:
fs/cifs/file.c:3578:20: warning: variable tcon set but not used [-Wunused-but-set-variable]

'cinode' is never used since introduced by
commit 03776f4516 ("CIFS: Simplify byte range locking code")
'cifs_sb' is not used since commit cb7e9eabb2 ("CIFS: Use
multicredits for SMB 2.1/3 writes").
'tcon' is not used since commit d26e2903fc ("smb3: fix bytes_read statistics")

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-09-16 11:43:37 -05:00
Steve French
df58fae724 smb3: Incorrect size for netname negotiate context
It is not null terminated (length was off by two).

Also see similar change to Samba:

https://gitlab.com/samba-team/samba/merge_requests/666

Reported-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-09-16 11:43:37 -05:00
zhengbin
2617474bfa cifs: remove unused variable
In smb3_punch_hole, variable cifsi set but not used, remove it.
In cifs_lock, variable netfid set but not used, remove it.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-09-16 11:43:37 -05:00
Colin Ian King
1efd4fc72e cifs: remove redundant assignment to variable rc
Variable rc is being initialized with a value that is never read
and rc is being re-assigned a little later on. The assignment is
redundant and hence 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>
2019-09-16 11:43:37 -05:00
Steve French
59519803a9 smb3: add missing flag definitions
SMB3 and 3.1.1 added two additional flags including
the priority mask.  Add them to our protocol definitions
in smb2pdu.h.  See MS-SMB2 2.2.1.2

Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2019-09-16 11:43:37 -05:00
Ronnie Sahlberg
0e90696dc2 cifs: add passthrough for smb2 setinfo
Add support to send smb2 set-info commands from userspace.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Paulo Alcantara <palcantara@suse.de>
2019-09-16 11:43:37 -05:00
Ronnie Sahlberg
86e14e1205 cifs: prepare SMB2_Flush to be usable in compounds
Create smb2_flush_init() and smb2_flush_free() so we can use the flush command
in compounds.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-09-16 11:43:37 -05:00
Steve French
22442179a5 cifs: allow chmod to set mode bits using special sid
When mounting with "modefromsid" set mode bits (chmod) by
    adding ACE with special SID (S-1-5-88-3-<mode>) to the ACL.
    Subsequent patch will fix setting default mode on file
    create and mkdir.

    See See e.g.
        https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2008-R2-and-2008/hh509017(v=ws.10)

Signed-off-by: Steve French <stfrench@microsoft.com>
2019-09-16 11:43:37 -05:00
Steve French
e2f8fbfb8d cifs: get mode bits from special sid on stat
When mounting with "modefromsid" retrieve mode bits from
special SID (S-1-5-88-3) on stat.  Subsequent patch will fix
setattr (chmod) to save mode bits in S-1-5-88-3-<mode>

Note that when an ACE matching S-1-5-88-3 is not found, we
default the mode to an approximation based on the owner, group
and everyone permissions (as with the "cifsacl" mount option).

See See e.g.
    https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2008-R2-and-2008/hh509017(v=ws.10)

Signed-off-by: Steve French <stfrench@microsoft.com>
2019-09-16 11:43:37 -05:00
Colin Ian King
1afdea4f19 fs: cifs: cifsssmb: remove redundant assignment to variable ret
The variable ret is being initialized however this is never read
and later it is being reassigned to a new value. The initialization
is redundant and hence 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>
2019-09-16 11:43:37 -05:00
Ronnie Sahlberg
becc2ba26a cifs: fix a comment for the timeouts when sending echos
Clarify a trivial comment

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-09-16 11:43:37 -05:00
Linus Torvalds
72dbcf7215 Revert "ext4: make __ext4_get_inode_loc plug"
This reverts commit b03755ad6f.

This is sad, and done for all the wrong reasons.  Because that commit is
good, and does exactly what it says: avoids a lot of small disk requests
for the inode table read-ahead.

However, it turns out that it causes an entirely unrelated problem: the
getrandom() system call was introduced back in 2014 by commit
c6e9d6f388 ("random: introduce getrandom(2) system call"), and people
use it as a convenient source of good random numbers.

But part of the current semantics for getrandom() is that it waits for
the entropy pool to fill at least partially (unlike /dev/urandom).  And
at least ArchLinux apparently has a systemd that uses getrandom() at
boot time, and the improvements in IO patterns means that existing
installations suddenly start hanging, waiting for entropy that will
never happen.

It seems to be an unlucky combination of not _quite_ enough entropy,
together with a particular systemd version and configuration.  Lennart
says that the systemd-random-seed process (which is what does this early
access) is supposed to not block any other boot activity, but sadly that
doesn't actually seem to be the case (possibly due bogus dependencies on
cryptsetup for encrypted swapspace).

The correct fix is to fix getrandom() to not block when it's not
appropriate, but that fix is going to take a lot more discussion.  Do we
just make it act like /dev/urandom by default, and add a new flag for
"wait for entropy"? Do we add a boot-time option? Or do we just limit
the amount of time it will wait for entropy?

So in the meantime, we do the revert to give us time to discuss the
eventual fix for the fundamental problem, at which point we can re-apply
the ext4 inode table access optimization.

Reported-by: Ahmed S. Darwish <darwish.07@gmail.com>
Cc: Ted Ts'o <tytso@mit.edu>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Alexander E. Patrakov <patrakov@gmail.com>
Cc: Lennart Poettering <mzxreary@0pointer.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-15 12:32:03 -07:00
Linus Torvalds
1b304a1ae4 for-5.3-rc8-tag
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Merge tag 'for-5.3-rc8-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:
 "Here are two fixes, one of them urgent fixing a bug introduced in 5.2
  and reported by many users. It took time to identify the root cause,
  catching the 5.3 release is higly desired also to push the fix to 5.2
  stable tree.

  The bug is a mess up of return values after adding proper error
  handling and honestly the kind of bug that can cause sleeping
  disorders until it's caught. My appologies to everybody who was
  affected.

  Summary of what could happen:

  1) either a hang when committing a transaction, if this happens
     there's no risk of corruption, still the hang is very inconvenient
     and can't be resolved without a reboot

  2) writeback for some btree nodes may never be started and we end up
     committing a transaction without noticing that, this is really
     serious and that will lead to the "parent transid verify failed"
     messages"

* tag 'for-5.3-rc8-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  Btrfs: fix unwritten extent buffers and hangs on future writeback attempts
  Btrfs: fix assertion failure during fsync and use of stale transaction
2019-09-13 09:48:47 +01:00
Filipe Manana
18dfa7117a Btrfs: fix unwritten extent buffers and hangs on future writeback attempts
The lock_extent_buffer_io() returns 1 to the caller to tell it everything
went fine and the callers needs to start writeback for the extent buffer
(submit a bio, etc), 0 to tell the caller everything went fine but it does
not need to start writeback for the extent buffer, and a negative value if
some error happened.

When it's about to return 1 it tries to lock all pages, and if a try lock
on a page fails, and we didn't flush any existing bio in our "epd", it
calls flush_write_bio(epd) and overwrites the return value of 1 to 0 or
an error. The page might have been locked elsewhere, not with the goal
of starting writeback of the extent buffer, and even by some code other
than btrfs, like page migration for example, so it does not mean the
writeback of the extent buffer was already started by some other task,
so returning a 0 tells the caller (btree_write_cache_pages()) to not
start writeback for the extent buffer. Note that epd might currently have
either no bio, so flush_write_bio() returns 0 (success) or it might have
a bio for another extent buffer with a lower index (logical address).

Since we return 0 with the EXTENT_BUFFER_WRITEBACK bit set on the
extent buffer and writeback is never started for the extent buffer,
future attempts to writeback the extent buffer will hang forever waiting
on that bit to be cleared, since it can only be cleared after writeback
completes. Such hang is reported with a trace like the following:

  [49887.347053] INFO: task btrfs-transacti:1752 blocked for more than 122 seconds.
  [49887.347059]       Not tainted 5.2.13-gentoo #2
  [49887.347060] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [49887.347062] btrfs-transacti D    0  1752      2 0x80004000
  [49887.347064] Call Trace:
  [49887.347069]  ? __schedule+0x265/0x830
  [49887.347071]  ? bit_wait+0x50/0x50
  [49887.347072]  ? bit_wait+0x50/0x50
  [49887.347074]  schedule+0x24/0x90
  [49887.347075]  io_schedule+0x3c/0x60
  [49887.347077]  bit_wait_io+0x8/0x50
  [49887.347079]  __wait_on_bit+0x6c/0x80
  [49887.347081]  ? __lock_release.isra.29+0x155/0x2d0
  [49887.347083]  out_of_line_wait_on_bit+0x7b/0x80
  [49887.347084]  ? var_wake_function+0x20/0x20
  [49887.347087]  lock_extent_buffer_for_io+0x28c/0x390
  [49887.347089]  btree_write_cache_pages+0x18e/0x340
  [49887.347091]  do_writepages+0x29/0xb0
  [49887.347093]  ? kmem_cache_free+0x132/0x160
  [49887.347095]  ? convert_extent_bit+0x544/0x680
  [49887.347097]  filemap_fdatawrite_range+0x70/0x90
  [49887.347099]  btrfs_write_marked_extents+0x53/0x120
  [49887.347100]  btrfs_write_and_wait_transaction.isra.4+0x38/0xa0
  [49887.347102]  btrfs_commit_transaction+0x6bb/0x990
  [49887.347103]  ? start_transaction+0x33e/0x500
  [49887.347105]  transaction_kthread+0x139/0x15c

So fix this by not overwriting the return value (ret) with the result
from flush_write_bio(). We also need to clear the EXTENT_BUFFER_WRITEBACK
bit in case flush_write_bio() returns an error, otherwise it will hang
any future attempts to writeback the extent buffer, and undo all work
done before (set back EXTENT_BUFFER_DIRTY, etc).

This is a regression introduced in the 5.2 kernel.

Fixes: 2e3c25136a ("btrfs: extent_io: add proper error handling to lock_extent_buffer_for_io()")
Fixes: f4340622e0 ("btrfs: extent_io: Move the BUG_ON() in flush_write_bio() one level up")
Reported-by: Zdenek Sojka <zsojka@seznam.cz>
Link: https://lore.kernel.org/linux-btrfs/GpO.2yos.3WGDOLpx6t%7D.1TUDYM@seznam.cz/T/#u
Reported-by: Stefan Priebe - Profihost AG <s.priebe@profihost.ag>
Link: https://lore.kernel.org/linux-btrfs/5c4688ac-10a7-fb07-70e8-c5d31a3fbb38@profihost.ag/T/#t
Reported-by: Drazen Kacar <drazen.kacar@oradian.com>
Link: https://lore.kernel.org/linux-btrfs/DB8PR03MB562876ECE2319B3E579590F799C80@DB8PR03MB5628.eurprd03.prod.outlook.com/
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=204377
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-12 13:37:25 +02:00
Filipe Manana
410f954cb1 Btrfs: fix assertion failure during fsync and use of stale transaction
Sometimes when fsync'ing a file we need to log that other inodes exist and
when we need to do that we acquire a reference on the inodes and then drop
that reference using iput() after logging them.

That generally is not a problem except if we end up doing the final iput()
(dropping the last reference) on the inode and that inode has a link count
of 0, which can happen in a very short time window if the logging path
gets a reference on the inode while it's being unlinked.

In that case we end up getting the eviction callback, btrfs_evict_inode(),
invoked through the iput() call chain which needs to drop all of the
inode's items from its subvolume btree, and in order to do that, it needs
to join a transaction at the helper function evict_refill_and_join().
However because the task previously started a transaction at the fsync
handler, btrfs_sync_file(), it has current->journal_info already pointing
to a transaction handle and therefore evict_refill_and_join() will get
that transaction handle from btrfs_join_transaction(). From this point on,
two different problems can happen:

1) evict_refill_and_join() will often change the transaction handle's
   block reserve (->block_rsv) and set its ->bytes_reserved field to a
   value greater than 0. If evict_refill_and_join() never commits the
   transaction, the eviction handler ends up decreasing the reference
   count (->use_count) of the transaction handle through the call to
   btrfs_end_transaction(), and after that point we have a transaction
   handle with a NULL ->block_rsv (which is the value prior to the
   transaction join from evict_refill_and_join()) and a ->bytes_reserved
   value greater than 0. If after the eviction/iput completes the inode
   logging path hits an error or it decides that it must fallback to a
   transaction commit, the btrfs fsync handle, btrfs_sync_file(), gets a
   non-zero value from btrfs_log_dentry_safe(), and because of that
   non-zero value it tries to commit the transaction using a handle with
   a NULL ->block_rsv and a non-zero ->bytes_reserved value. This makes
   the transaction commit hit an assertion failure at
   btrfs_trans_release_metadata() because ->bytes_reserved is not zero but
   the ->block_rsv is NULL. The produced stack trace for that is like the
   following:

   [192922.917158] assertion failed: !trans->bytes_reserved, file: fs/btrfs/transaction.c, line: 816
   [192922.917553] ------------[ cut here ]------------
   [192922.917922] kernel BUG at fs/btrfs/ctree.h:3532!
   [192922.918310] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC PTI
   [192922.918666] CPU: 2 PID: 883 Comm: fsstress Tainted: G        W         5.1.4-btrfs-next-47 #1
   [192922.919035] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626ccb91-prebuilt.qemu-project.org 04/01/2014
   [192922.919801] RIP: 0010:assfail.constprop.25+0x18/0x1a [btrfs]
   (...)
   [192922.920925] RSP: 0018:ffffaebdc8a27da8 EFLAGS: 00010286
   [192922.921315] RAX: 0000000000000051 RBX: ffff95c9c16a41c0 RCX: 0000000000000000
   [192922.921692] RDX: 0000000000000000 RSI: ffff95cab6b16838 RDI: ffff95cab6b16838
   [192922.922066] RBP: ffff95c9c16a41c0 R08: 0000000000000000 R09: 0000000000000000
   [192922.922442] R10: ffffaebdc8a27e70 R11: 0000000000000000 R12: ffff95ca731a0980
   [192922.922820] R13: 0000000000000000 R14: ffff95ca84c73338 R15: ffff95ca731a0ea8
   [192922.923200] FS:  00007f337eda4e80(0000) GS:ffff95cab6b00000(0000) knlGS:0000000000000000
   [192922.923579] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
   [192922.923948] CR2: 00007f337edad000 CR3: 00000001e00f6002 CR4: 00000000003606e0
   [192922.924329] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
   [192922.924711] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
   [192922.925105] Call Trace:
   [192922.925505]  btrfs_trans_release_metadata+0x10c/0x170 [btrfs]
   [192922.925911]  btrfs_commit_transaction+0x3e/0xaf0 [btrfs]
   [192922.926324]  btrfs_sync_file+0x44c/0x490 [btrfs]
   [192922.926731]  do_fsync+0x38/0x60
   [192922.927138]  __x64_sys_fdatasync+0x13/0x20
   [192922.927543]  do_syscall_64+0x60/0x1c0
   [192922.927939]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
   (...)
   [192922.934077] ---[ end trace f00808b12068168f ]---

2) If evict_refill_and_join() decides to commit the transaction, it will
   be able to do it, since the nested transaction join only increments the
   transaction handle's ->use_count reference counter and it does not
   prevent the transaction from getting committed. This means that after
   eviction completes, the fsync logging path will be using a transaction
   handle that refers to an already committed transaction. What happens
   when using such a stale transaction can be unpredictable, we are at
   least having a use-after-free on the transaction handle itself, since
   the transaction commit will call kmem_cache_free() against the handle
   regardless of its ->use_count value, or we can end up silently losing
   all the updates to the log tree after that iput() in the logging path,
   or using a transaction handle that in the meanwhile was allocated to
   another task for a new transaction, etc, pretty much unpredictable
   what can happen.

In order to fix both of them, instead of using iput() during logging, use
btrfs_add_delayed_iput(), so that the logging path of fsync never drops
the last reference on an inode, that step is offloaded to a safe context
(usually the cleaner kthread).

The assertion failure issue was sporadically triggered by the test case
generic/475 from fstests, which loads the dm error target while fsstress
is running, which lead to fsync failing while logging inodes with -EIO
errors and then trying later to commit the transaction, triggering the
assertion failure.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-09-12 13:37:19 +02:00
Linus Torvalds
30d7030b2f configfs fixes for 5.3
- fix removal vs attribute read/write races (Al Viro)
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Merge tag 'configfs-for-5.3' of git://git.infradead.org/users/hch/configfs

Pull configfs fixes from Christoph Hellwig:
 "Late configfs fixes from Al that fix pretty nasty removal vs attribute
  access races"

* tag 'configfs-for-5.3' of git://git.infradead.org/users/hch/configfs:
  configfs: provide exclusion between IO and removals
  configfs: new object reprsenting tree fragments
  configfs_register_group() shouldn't be (and isn't) called in rmdirable parts
  configfs: stash the data we need into configfs_buffer at open time
2019-09-06 12:44:08 -07:00
Al Viro
b0841eefd9 configfs: provide exclusion between IO and removals
Make sure that attribute methods are not called after the item
has been removed from the tree.  To do so, we
	* at the point of no return in removals, grab ->frag_sem
exclusive and mark the fragment dead.
	* call the methods of attributes with ->frag_sem taken
shared and only after having verified that the fragment is still
alive.

	The main benefit is for method instances - they are
guaranteed that the objects they are accessing *and* all ancestors
are still there.  Another win is that we don't need to bother
with extra refcount on config_item when opening a file -
the item will be alive for as long as it stays in the tree, and
we won't touch it/attributes/any associated data after it's
been removed from the tree.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-09-04 22:33:51 +02:00
Al Viro
47320fbe11 configfs: new object reprsenting tree fragments
Refcounted, hangs of configfs_dirent, created by operations that add
fragments to configfs tree (mkdir and configfs_register_{subsystem,group}).
Will be used in the next commit to provide exclusion between fragment
removal and ->show/->store calls.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-09-02 22:10:44 +02:00
Al Viro
f19e4ed1e1 configfs_register_group() shouldn't be (and isn't) called in rmdirable parts
revert cc57c07343 "configfs: fix registered group removal"
It was an attempt to handle something that fundamentally doesn't
work - configfs_register_group() should never be done in a part
of tree that can be rmdir'ed.  And in mainline it never had been,
so let's not borrow trouble; the fix was racy anyway, it would take
a lot more to make that work and desired semantics is not clear.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-09-02 22:10:44 +02:00
Al Viro
ff4dd08197 configfs: stash the data we need into configfs_buffer at open time
simplifies the ->read()/->write()/->release() instances nicely

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-09-02 22:10:43 +02:00
Trond Myklebust
eb3d8f4223 NFS: Fix inode fileid checks in attribute revalidation code
We want to throw out the attrbute if it refers to the mounted on fileid,
and not the real fileid. However we do not want to block cache consistency
updates from NFSv4 writes.

Reported-by: Murphy Zhou <jencce.kernel@gmail.com>
Fixes: 7e10cc25bf ("NFS: Don't refresh attributes with mounted-on-file...")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-09-02 13:10:19 -04:00
Linus Torvalds
2653810049 a few small SMB3 fixes, and a larger one to fix various older string handling functions
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Merge tag '5.3-rc6-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs fixes from Steve French:
 "A few small SMB3 fixes, and a larger one to fix various older string
  handling functions"

* tag '5.3-rc6-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: update internal module number
  cifs: replace various strncpy with strscpy and similar
  cifs: Use kzfree() to zero out the password
  cifs: set domainName when a domain-key is used in multiuser
2019-08-29 17:51:23 -07:00
Steve French
36e337744c cifs: update internal module number
To 2.22

Signed-off-by: Steve French <stfrench@microsoft.com>
2019-08-27 17:29:56 -05:00
Ronnie Sahlberg
340625e618 cifs: replace various strncpy with strscpy and similar
Using strscpy is cleaner, and avoids some problems with
handling maximum length strings.  Linus noticed the
original problem and Aurelien pointed out some additional
problems. Fortunately most of this is SMB1 code (and
in particular the ASCII string handling older, which
is less common).

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-08-27 17:25:12 -05:00
Dan Carpenter
478228e57f cifs: Use kzfree() to zero out the password
It's safer to zero out the password so that it can never be disclosed.

Fixes: 0c219f5799c7 ("cifs: set domainName when a domain-key is used in multiuser")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-08-27 16:44:27 -05:00
Ronnie Sahlberg
f2aee329a6 cifs: set domainName when a domain-key is used in multiuser
RHBZ: 1710429

When we use a domain-key to authenticate using multiuser we must also set
the domainnmame for the new volume as it will be used and passed to the server
in the NTLMSSP Domain-name.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-08-27 16:44:24 -05:00
Linus Torvalds
9e8312f5e1 NFS client bugfixes for Linux 5.3
Highlights include:
 
 Stable fixes:
 - Fix a page lock leak in nfs_pageio_resend()
 - Ensure O_DIRECT reports an error if the bytes read/written is 0
 - Don't handle errors if the bind/connect succeeded
 - Revert "NFSv4/flexfiles: Abort I/O early if the layout segment was invalidat
 ed"
 
 Bugfixes:
 - Don't refresh attributes with mounted-on-file information
 - Fix return values for nfs4_file_open() and nfs_finish_open()
 - Fix pnfs layoutstats reporting of I/O errors
 - Don't use soft RPC calls for pNFS/flexfiles I/O, and don't abort for
   soft I/O errors when the user specifies a hard mount.
 - Various fixes to the error handling in sunrpc
 - Don't report writepage()/writepages() errors twice.
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Merge tag 'nfs-for-5.3-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client bugfixes from Trond Myklebust:
 "Highlights include:

  Stable fixes:

   - Fix a page lock leak in nfs_pageio_resend()

   - Ensure O_DIRECT reports an error if the bytes read/written is 0

   - Don't handle errors if the bind/connect succeeded

   - Revert "NFSv4/flexfiles: Abort I/O early if the layout segment was
     invalidat ed"

  Bugfixes:

   - Don't refresh attributes with mounted-on-file information

   - Fix return values for nfs4_file_open() and nfs_finish_open()

   - Fix pnfs layoutstats reporting of I/O errors

   - Don't use soft RPC calls for pNFS/flexfiles I/O, and don't abort
     for soft I/O errors when the user specifies a hard mount.

   - Various fixes to the error handling in sunrpc

   - Don't report writepage()/writepages() errors twice"

* tag 'nfs-for-5.3-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  NFS: remove set but not used variable 'mapping'
  NFSv2: Fix write regression
  NFSv2: Fix eof handling
  NFS: Fix writepage(s) error handling to not report errors twice
  NFS: Fix spurious EIO read errors
  pNFS/flexfiles: Don't time out requests on hard mounts
  SUNRPC: Handle connection breakages correctly in call_status()
  Revert "NFSv4/flexfiles: Abort I/O early if the layout segment was invalidated"
  SUNRPC: Handle EADDRINUSE and ENOBUFS correctly
  pNFS/flexfiles: Turn off soft RPC calls
  SUNRPC: Don't handle errors if the bind/connect succeeded
  NFS: On fatal writeback errors, we need to call nfs_inode_remove_request()
  NFS: Fix initialisation of I/O result struct in nfs_pgio_rpcsetup
  NFS: Ensure O_DIRECT reports an error if the bytes read/written is 0
  NFSv4/pnfs: Fix a page lock leak in nfs_pageio_resend()
  NFSv4: Fix return value in nfs_finish_open()
  NFSv4: Fix return values for nfs4_file_open()
  NFS: Don't refresh attributes with mounted-on-file information
2019-08-27 13:22:57 -07:00
YueHaibing
99300a8526 NFS: remove set but not used variable 'mapping'
Fixes gcc '-Wunused-but-set-variable' warning:

fs/nfs/write.c: In function nfs_page_async_flush:
fs/nfs/write.c:609:24: warning: variable mapping set but not used [-Wunused-but-set-variable]

It is not use since commit aefb623c422e ("NFS: Fix
writepage(s) error handling to not report errors twice")

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-08-27 10:24:56 -04:00
Trond Myklebust
d33d4beb52 NFSv2: Fix write regression
Ensure we update the write result count on success, since the
RPC call itself does not do so.

Reported-by: Jan Stancek <jstancek@redhat.com>
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Tested-by: Jan Stancek <jstancek@redhat.com>
2019-08-27 10:24:56 -04:00
Trond Myklebust
71affe9be4 NFSv2: Fix eof handling
If we received a reply from the server with a zero length read and
no error, then that implies we are at eof.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-08-27 10:24:56 -04:00
Trond Myklebust
96c4145599 NFS: Fix writepage(s) error handling to not report errors twice
If writepage()/writepages() saw an error, but handled it without
reporting it, we should not be re-reporting that error on exit.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-08-26 15:31:29 -04:00