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Merge tag '5.17-rc-part1-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6
Pull cifs updates from Steve French:
- multichannel patches mostly related to improving reconnect behavior
- minor cleanup patches
* tag '5.17-rc-part1-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
cifs: fix FILE_BOTH_DIRECTORY_INFO definition
cifs: move superblock magic defitions to magic.h
cifs: Fix smb311_update_preauth_hash() kernel-doc comment
cifs: avoid race during socket reconnect between send and recv
cifs: maintain a state machine for tcp/smb/tcon sessions
cifs: fix hang on cifs_get_next_mid()
cifs: take cifs_tcp_ses_lock for status checks
cifs: reconnect only the connection and not smb session where possible
cifs: add WARN_ON for when chan_count goes below minimum
cifs: adjust DebugData to use chans_need_reconnect for conn status
cifs: use the chans_need_reconnect bitmap for reconnect status
cifs: track individual channel status using chans_need_reconnect
cifs: remove redundant assignment to pointer p
Pull signal/exit/ptrace updates from Eric Biederman:
"This set of changes deletes some dead code, makes a lot of cleanups
which hopefully make the code easier to follow, and fixes bugs found
along the way.
The end-game which I have not yet reached yet is for fatal signals
that generate coredumps to be short-circuit deliverable from
complete_signal, for force_siginfo_to_task not to require changing
userspace configured signal delivery state, and for the ptrace stops
to always happen in locations where we can guarantee on all
architectures that the all of the registers are saved and available on
the stack.
Removal of profile_task_ext, profile_munmap, and profile_handoff_task
are the big successes for dead code removal this round.
A bunch of small bug fixes are included, as most of the issues
reported were small enough that they would not affect bisection so I
simply added the fixes and did not fold the fixes into the changes
they were fixing.
There was a bug that broke coredumps piped to systemd-coredump. I
dropped the change that caused that bug and replaced it entirely with
something much more restrained. Unfortunately that required some
rebasing.
Some successes after this set of changes: There are few enough calls
to do_exit to audit in a reasonable amount of time. The lifetime of
struct kthread now matches the lifetime of struct task, and the
pointer to struct kthread is no longer stored in set_child_tid. The
flag SIGNAL_GROUP_COREDUMP is removed. The field group_exit_task is
removed. Issues where task->exit_code was examined with
signal->group_exit_code should been examined were fixed.
There are several loosely related changes included because I am
cleaning up and if I don't include them they will probably get lost.
The original postings of these changes can be found at:
https://lkml.kernel.org/r/87a6ha4zsd.fsf@email.froward.int.ebiederm.orghttps://lkml.kernel.org/r/87bl1kunjj.fsf@email.froward.int.ebiederm.orghttps://lkml.kernel.org/r/87r19opkx1.fsf_-_@email.froward.int.ebiederm.org
I trimmed back the last set of changes to only the obviously correct
once. Simply because there was less time for review than I had hoped"
* 'signal-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (44 commits)
ptrace/m68k: Stop open coding ptrace_report_syscall
ptrace: Remove unused regs argument from ptrace_report_syscall
ptrace: Remove second setting of PT_SEIZED in ptrace_attach
taskstats: Cleanup the use of task->exit_code
exit: Use the correct exit_code in /proc/<pid>/stat
exit: Fix the exit_code for wait_task_zombie
exit: Coredumps reach do_group_exit
exit: Remove profile_handoff_task
exit: Remove profile_task_exit & profile_munmap
signal: clean up kernel-doc comments
signal: Remove the helper signal_group_exit
signal: Rename group_exit_task group_exec_task
coredump: Stop setting signal->group_exit_task
signal: Remove SIGNAL_GROUP_COREDUMP
signal: During coredumps set SIGNAL_GROUP_EXIT in zap_process
signal: Make coredump handling explicit in complete_signal
signal: Have prepare_signal detect coredumps using signal->core_state
signal: Have the oom killer detect coredumps using signal->core_state
exit: Move force_uaccess back into do_exit
exit: Guarantee make_task_dead leaks the tsk when calling do_task_exit
...
The size of FILE_BOTH_DIRECTORY_INFO.ShortName must be 24 bytes, not 12
(see MS-FSCC documentation).
Signed-off-by: Eugene Korenevsky <ekorenevsky@astralinux.ru>
Signed-off-by: Steve French <stfrench@microsoft.com>
Help userland apps to identify cifs and smb2 mounts.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Add the description of @server in smb311_update_preauth_hash()
kernel-doc comment to remove warning found by running scripts/kernel-doc,
which is caused by using 'make W=1'.
fs/cifs/smb2misc.c:856: warning: Function parameter or member 'server'
not described in 'smb311_update_preauth_hash'
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
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Merge tag 'fscache-rewrite-20220111' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull fscache rewrite from David Howells:
"This is a set of patches that rewrites the fscache driver and the
cachefiles driver, significantly simplifying the code compared to
what's upstream, removing the complex operation scheduling and object
state machine in favour of something much smaller and simpler.
The series is structured such that the first few patches disable
fscache use by the network filesystems using it, remove the cachefiles
driver entirely and as much of the fscache driver as can be got away
with without causing build failures in the network filesystems.
The patches after that recreate fscache and then cachefiles,
attempting to add the pieces in a logical order. Finally, the
filesystems are reenabled and then the very last patch changes the
documentation.
[!] Note: I have dropped the cifs patch for the moment, leaving local
caching in cifs disabled. I've been having trouble getting that
working. I think I have it done, but it needs more testing (there
seem to be some test failures occurring with v5.16 also from
xfstests), so I propose deferring that patch to the end of the
merge window.
WHY REWRITE?
============
Fscache's operation scheduling API was intended to handle sequencing
of cache operations, which were all required (where possible) to run
asynchronously in parallel with the operations being done by the
network filesystem, whilst allowing the cache to be brought online and
offline and to interrupt service for invalidation.
With the advent of the tmpfile capacity in the VFS, however, an
opportunity arises to do invalidation much more simply, without having
to wait for I/O that's actually in progress: Cachefiles can simply
create a tmpfile, cut over the file pointer for the backing object
attached to a cookie and abandon the in-progress I/O, dismissing it
upon completion.
Future work here would involve using Omar Sandoval's vfs_link() with
AT_LINK_REPLACE[1] to allow an extant file to be displaced by a new
hard link from a tmpfile as currently I have to unlink the old file
first.
These patches can also simplify the object state handling as I/O
operations to the cache don't all have to be brought to a stop in
order to invalidate a file. To that end, and with an eye on to writing
a new backing cache model in the future, I've taken the opportunity to
simplify the indexing structure.
I've separated the index cookie concept from the file cookie concept
by C type now. The former is now called a "volume cookie" (struct
fscache_volume) and there is a container of file cookies. There are
then just the two levels. All the index cookie levels are collapsed
into a single volume cookie, and this has a single printable string as
a key. For instance, an AFS volume would have a key of something like
"afs,example.com,1000555", combining the filesystem name, cell name
and volume ID. This is freeform, but must not have '/' chars in it.
I've also eliminated all pointers back from fscache into the network
filesystem. This required the duplication of a little bit of data in
the cookie (cookie key, coherency data and file size), but it's not
actually that much. This gets rid of problems with making sure we keep
netfs data structures around so that the cache can access them.
These patches mean that most of the code that was in the drivers
before is simply gone and those drivers are now almost entirely new
code. That being the case, there doesn't seem any particular reason to
try and maintain bisectability across it. Further, there has to be a
point in the middle where things are cut over as there's a single
point everything has to go through (ie. /dev/cachefiles) and it can't
be in use by two drivers at once.
ISSUES YET OUTSTANDING
======================
There are some issues still outstanding, unaddressed by this patchset,
that will need fixing in future patchsets, but that don't stop this
series from being usable:
(1) The cachefiles driver needs to stop using the backing filesystem's
metadata to store information about what parts of the cache are
populated. This is not reliable with modern extent-based
filesystems.
Fixing this is deferred to a separate patchset as it involves
negotiation with the network filesystem and the VM as to how much
data to download to fulfil a read - which brings me on to (2)...
(2) NFS (and CIFS with the dropped patch) do not take account of how
the cache would like I/O to be structured to meet its granularity
requirements. Previously, the cache used page granularity, which
was fine as the network filesystems also dealt in page
granularity, and the backing filesystem (ext4, xfs or whatever)
did whatever it did out of sight. However, we now have folios to
deal with and the cache will now have to store its own metadata to
track its contents.
The change I'm looking at making for cachefiles is to store
content bitmaps in one or more xattrs and making a bit in the map
correspond to something like a 256KiB block. However, the size of
an xattr and the fact that they have to be read/updated in one go
means that I'm looking at covering 1GiB of data per 512-byte map
and storing each map in an xattr. Cachefiles has the potential to
grow into a fully fledged filesystem of its very own if I'm not
careful.
However, I'm also looking at changing things even more radically
and going to a different model of how the cache is arranged and
managed - one that's more akin to the way, say, openafs does
things - which brings me on to (3)...
(3) The way cachefilesd does culling is very inefficient for large
caches and it would be better to move it into the kernel if I can
as cachefilesd has to keep asking the kernel if it can cull a
file. Changing the way the backend works would allow this to be
addressed.
BITS THAT MAY BE CONTROVERSIAL
==============================
There are some bits I've added that may be controversial:
(1) I've provided a flag, S_KERNEL_FILE, that cachefiles uses to check
if a files is already being used by some other kernel service
(e.g. a duplicate cachefiles cache in the same directory) and
reject it if it is. This isn't entirely necessary, but it helps
prevent accidental data corruption.
I don't want to use S_SWAPFILE as that has other effects, but
quite possibly swapon() should set S_KERNEL_FILE too.
Note that it doesn't prevent userspace from interfering, though
perhaps it should. (I have made it prevent a marked directory from
being rmdir-able).
(2) Cachefiles wants to keep the backing file for a cookie open whilst
we might need to write to it from network filesystem writeback.
The problem is that the network filesystem unuses its cookie when
its file is closed, and so we have nothing pinning the cachefiles
file open and it will get closed automatically after a short time
to avoid EMFILE/ENFILE problems.
Reopening the cache file, however, is a problem if this is being
done due to writeback triggered by exit(). Some filesystems will
oops if we try to open a file in that context because they want to
access current->fs or suchlike.
To get around this, I added the following:
(A) An inode flag, I_PINNING_FSCACHE_WB, to be set on a network
filesystem inode to indicate that we have a usage count on the
cookie caching that inode.
(B) A flag in struct writeback_control, unpinned_fscache_wb, that
is set when __writeback_single_inode() clears the last dirty
page from i_pages - at which point it clears
I_PINNING_FSCACHE_WB and sets this flag.
This has to be done here so that clearing I_PINNING_FSCACHE_WB
can be done atomically with the check of PAGECACHE_TAG_DIRTY
that clears I_DIRTY_PAGES.
(C) A function, fscache_set_page_dirty(), which if it is not set,
sets I_PINNING_FSCACHE_WB and calls fscache_use_cookie() to
pin the cache resources.
(D) A function, fscache_unpin_writeback(), to be called by
->write_inode() to unuse the cookie.
(E) A function, fscache_clear_inode_writeback(), to be called when
the inode is evicted, before clear_inode() is called. This
cleans up any lingering I_PINNING_FSCACHE_WB.
The network filesystem can then use these tools to make sure that
fscache_write_to_cache() can write locally modified data to the
cache as well as to the server.
For the future, I'm working on write helpers for netfs lib that
should allow this facility to be removed by keeping track of the
dirty regions separately - but that's incomplete at the moment and
is also going to be affected by folios, one way or another, since
it deals with pages"
Link: https://lore.kernel.org/all/510611.1641942444@warthog.procyon.org.uk/
Tested-by: Dominique Martinet <asmadeus@codewreck.org> # 9p
Tested-by: kafs-testing@auristor.com # afs
Tested-by: Jeff Layton <jlayton@kernel.org> # ceph
Tested-by: Dave Wysochanski <dwysocha@redhat.com> # nfs
Tested-by: Daire Byrne <daire@dneg.com> # nfs
* tag 'fscache-rewrite-20220111' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: (67 commits)
9p, afs, ceph, nfs: Use current_is_kswapd() rather than gfpflags_allow_blocking()
fscache: Add a tracepoint for cookie use/unuse
fscache: Rewrite documentation
ceph: add fscache writeback support
ceph: conversion to new fscache API
nfs: Implement cache I/O by accessing the cache directly
nfs: Convert to new fscache volume/cookie API
9p: Copy local writes to the cache when writing to the server
9p: Use fscache indexing rewrite and reenable caching
afs: Skip truncation on the server of data we haven't written yet
afs: Copy local writes to the cache when writing to the server
afs: Convert afs to use the new fscache API
fscache, cachefiles: Display stat of culling events
fscache, cachefiles: Display stats of no-space events
cachefiles: Allow cachefiles to actually function
fscache, cachefiles: Store the volume coherency data
cachefiles: Implement the I/O routines
cachefiles: Implement cookie resize for truncate
cachefiles: Implement begin and end I/O operation
cachefiles: Implement backing file wrangling
...
When a TCP connection gets reestablished by the sender in cifs_reconnect,
There is a chance for race condition with demultiplex thread waiting in
cifs_readv_from_socket on the old socket. It will now return -ECONNRESET.
This condition is handled by comparing socket pointer before and after
sock_recvmsg. If the socket pointer has changed, we should not call
cifs_reconnect again, but instead retry with new socket.
Also fixed another bug in my prev mchan commits.
We should always reestablish session (even if binding) on a channel
that needs reconnection.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
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>
Mount will hang if using SMB1 and DFS.
This is because every call to get_next_mid() will, unconditionally,
mark tcpStatus to CifsNeedReconnect before even establishing the
initial connect, because "reconnect" variable was not initialized.
Initializing "reconnect" to false fix this issue.
Fixes: 220c5bc25d87 ("cifs: take cifs_tcp_ses_lock for status checks")
Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
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>
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>
chan_count keeps track of the total number of channels.
Since at least the primary channel will always be connected,
this value can never go below 1. Warn if that happens.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Use ses->chans_need_reconnect bitmask to print the connection
status of each channel under an SMB session.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
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>
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>
The pointer p is being assigned with a value that is never read. The
pointer is being re-assigned a different value inside the do-while
loop. The assignment is redundant and can be removed.
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
mount.cifs can pass a device with multiple delimiters in it. This will
cause rename(2) to fail with ENOENT.
V2:
- Make sanitize_path more readable.
- Fix multiple delimiters between UNC and prepath.
- Avoid a memory leak if a bad user starts putting a lot of delimiters
in the path on purpose.
BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=2031200
Fixes: 24e0a1eff9 ("cifs: switch to new mount api")
Cc: stable@vger.kernel.org # 5.11+
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Thiago Rafael Becker <trbecker@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
We have a cyclic dependency between fscache super cookie
and root inode cookie. The super cookie relies on
tcon->resource_id, which gets populated from the root inode
number. However, fetching the root inode initializes inode
cookie as a child of super cookie, which is yet to be populated.
resource_id is only used as auxdata to check the validity of
super cookie. We can completely avoid setting resource_id to
remove the circular dependency. Since vol creation time and
vol serial numbers are used for auxdata, we should be fine.
Additionally, there will be auxiliary data check for each
inode cookie as well.
Fixes: 5bf91ef03d ("cifs: wait for tcon resource_id before getting fscache super")
CC: David Howells <dhowells@redhat.com>
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Update module_put_and_exit to call kthread_exit instead of do_exit.
Change the name to reflect this change in functionality. All of the
users of module_put_and_exit are causing the current kthread to exit
so this change makes it clear what is happening. There is no
functional change.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Warn on the lack of key exchange during NTLMSSP authentication rather
than aborting it as there are some servers that do not set it in
CHALLENGE message.
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
server->dstaddr can change when the DNS mapping for the
server hostname changes. But conn_id is a u64 counter
that is incremented each time a new TCP connection
is setup. So use only that as a key.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
The fscache client cookie uses the server address
(and port) as the cookie key. This is a problem when
nosharesock is used. Two different connections will
use duplicate cookies. Avoid this by adding
server->conn_id to the key, so that it's guaranteed
that cookie will not be duplicated.
Also, for secondary channels of a session, copy the
fscache pointer from the primary channel. The primary
channel is guaranteed not to go away as long as secondary
channels are in use. Also addresses minor problem found
by kernel test robot.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
The logic for initializing tcon->resource_id is done inside
cifs_root_iget. fscache super cookie relies on this for aux
data. So we need to push the fscache initialization to this
later point during mount.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Fix missed refcounting of IPC tcon used for getting domain-based DFS
root referrals. We want to keep it alive as long as mount is active
and can be refreshed. For standalone DFS root referrals it wouldn't
be a problem as the client ends up having an IPC tcon for both mount
and cache.
Fixes: c88f7dcd6d ("cifs: support nested dfs links over reconnect")
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
It is clearer to initialize rc at the beginning of the function.
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Recently, a new field got added to the smb3_fs_context struct
named server_hostname. While creating extra channels, pick up
this field from primary channel.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Recent fix to maintain a nosharesock state on the
server struct caused a regression. It updated this
field in the old tcp session, and not the new one.
This caused the multichannel scenario to misbehave.
Fixes: c9f1c19cf7 (cifs: nosharesock should not share socket with future sessions)
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Use new cifs_ses_mark_for_reconnect() helper to mark all session
channels for reconnect instead of duplicating it in different places.
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Updates to the srv_count field are protected elsewhere
with the cifs_tcp_ses_lock spinlock. Add one missing place
(cifs_get_tcp_sesion).
CC: Shyam Prasad N <sprasad@microsoft.com>
Addresses-Coverity: 1494149 ("Data Race Condition")
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
It is better to print debug messages outside of the chan_lock
spinlock where possible.
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Addresses-Coverity: 1493854 ("Thread deadlock")
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
We allocate index cookies for each connection from the client.
However, we don't need this index for each channel in case of
multichannel. So making sure that we avoid creating duplicate
cookies by instantiating only for primary channel.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Today, we don't have any way to get the smb session for any
of the secondary channels. Introducing a pointer to the primary
server from server struct of any secondary channel. The value will
be NULL for the server of the primary channel. This will enable us
to get the smb session for any channel.
This will be needed for some of the changes that I'm planning
to make soon.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Introducing a new spin lock to protect all the channel related
fields in a cifs_ses struct. This lock should be taken
whenever dealing with the channel fields, and should be held
only for very short intervals which will not sleep.
Currently, all channel related fields in cifs_ses structure
are protected by session_mutex. However, this mutex is held for
long periods (sometimes while waiting for a reply from server).
This makes the codepath quite tricky to change.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
In cifs_get_smb_ses, if we find an existing matching session,
we should not send a negotiate request for the session if a
session reconnect is not necessary.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
We were calling cifs_fscache_get_super_cookie after tcon but before
we queried the info (QFS_Info) we need to initialize the cookie
properly. Also includes an additional check suggested by Paulo
to make sure we don't initialize super cookie twice.
Suggested-by: David Howells <dhowells@redhat.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Ensure that share and prefix variables are set to NULL after kfree()
when looping through DFS targets in __tree_connect_dfs_target().
Also, get rid of @ref in __tree_connect_dfs_target() and just pass a
boolean to indicate whether we're handling link targets or not.
Fixes: c88f7dcd6d ("cifs: support nested dfs links over reconnect")
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Although unlikely for it to be possible for rsp to be null here,
the check is safer to add, and quiets a Coverity warning.
Addresses-Coverity: 1437501 ("Explicit Null dereference")
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
In dequeue_mid we can log an error while holding a spinlock,
GlobalMid_Lock. Coverity notes that the error logging
also grabs a lock so it is cleaner (and a bit safer) to
release the GlobalMid_Lock before logging the warning.
Addresses-Coverity: 1507573 ("Thread deadlock")
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Although unlikely to be possible for rsp to be null here,
the check is safer to add, and quiets a Coverity warning.
Addresses-Coverity: 1420428 ("Explicit null dereferenced")
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Although unlikely to be possible for rsp to be null here,
the check is safer to add, and quiets a Coverity warning.
Addresses-Coverity: 1418458 ("Explicit null dereferenced")
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Although unlikely for it to be possible for rsp to be null here,
the check is safer to add, and quiets a Coverity warning.
Addresses-Coverity: 1443909 ("Explicit Null dereference")
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Fix warning caused by recent changes to the dfs code:
symbol 'tree_connect_dfs_target' was not declared. Should it be static?
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Mounting a dfs link that has nested links was already supported at
mount(2), so make it work over reconnect as well.
Make the following case work:
* mount //root/dfs/link /mnt -o ...
- final share: /server/share
* in server settings
- change target folder of /root/dfs/link3 to /server/share2
- change target folder of /root/dfs/link2 to /root/dfs/link3
- change target folder of /root/dfs/link to /root/dfs/link2
* mount -o remount,... /mnt
- refresh all dfs referrals
- mark current connection for failover
- cifs_reconnect() reconnects to root server
- tree_connect()
* checks that /root/dfs/link2 is a link, then chase it
* checks that root/dfs/link3 is a link, then chase it
* finally tree connect to /server/share2
If the mounted share is no longer accessible and a reconnect had been
triggered, the client will retry it from both last referral
path (/root/dfs/link3) and original referral path (/root/dfs/link).
Any new referral paths found while chasing dfs links over reconnect,
it will be updated to TCP_Server_Info::leaf_fullpath, accordingly.
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Linux allows doing a flush/fsync on a file open for read-only,
but the protocol does not allow that. If the file passed in
on the flush is read-only try to find a writeable handle for
the same inode, if that is not possible skip sending the
fsync call to the server to avoid breaking the apps.
Reported-by: Julian Sikorski <belegdol@gmail.com>
Tested-by: Julian Sikorski <belegdol@gmail.com>
Suggested-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
For smb2_compound_op, it is possible to pass a ref to
an already open file. We should be passing it whenever possible.
i.e. if a matching handle is already kept open.
If we don't do that, we will end up breaking leases for files
kept open on the same client.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
With commit 506c1da44f ("cifs: use the expiry output of dns_query to
schedule next resolution") and after triggering the first reconnect,
the next async dns resolution of tcp server's hostname would be
scheduled based on dns_resolver's key expiry default, which happens to
default to 5s on most systems that use key.dns_resolver for upcall.
As per key.dns_resolver.conf(5):
default_ttl=<number>
The number of seconds to set as the expiration on a cached
record. This will be overridden if the program manages to re-
trieve TTL information along with the addresses (if, for exam-
ple, it accesses the DNS directly). The default is 5 seconds.
The value must be in the range 1 to INT_MAX.
Make the next async dns resolution no shorter than 120s as we do not
want to be upcalling too often.
Cc: stable@vger.kernel.org
Fixes: 506c1da44f ("cifs: use the expiry output of dns_query to schedule next resolution")
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Make two separate functions that handle dfs and non-dfs reconnect
logics since cifs_reconnect() became way too complex to handle both.
While at it, add some documentation.
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Linus Torvalds