We do this by abandoning the global list of SMB sessions and instead
moving to a per-server list. This entails adding a new list head to the
TCP_Server_Info struct. The refcounting for the cifsSesInfo is moved to
a non-atomic variable. We have to protect it by a lock anyway, so there's
no benefit to making it an atomic. The list and refcount are protected
by the global cifs_tcp_ses_lock.
The patch also adds a new routines to find and put SMB sessions and
that properly take and put references under the lock.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
The code that allows these structs to be shared is extremely racy.
Disable the sharing of SMB and tcon structs for now until we can
come up with a way to do this that's race free.
We want to continue to share TCP sessions, however since they are
required for multiuser mounts. For that, implement a new (hopefully
race-free) scheme. Add a new global list of TCP sessions, and take
care to get a reference to it whenever we're dealing with one.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
We're currently declaring both a sockaddr_in and sockaddr6_in on the
stack, but we really only need storage for one of them. Declare a
sockaddr struct and cast it to the proper type. Also, eliminate the
protocolType field in the TCP_Server_Info struct. It's redundant since
we have a sa_family field in the sockaddr anyway.
We may need to revisit this if SCTP is ever implemented, but for now
this will simplify the code.
CIFS over IPv6 also has a number of problems currently. This fixes all
of them that I found. Eventually, it would be nice to move more of the
code to be protocol independent, but this is a start.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Also adds two lines missing from the previous patch (for the need reconnect flag in the
/proc/fs/cifs/DebugData handling)
The new global_cifs_sock_list is added, and initialized in init_cifs but not used yet.
Jeff Layton will be adding code in to use that and to remove the GlobalTcon and GlobalSMBSession
lists.
CC: Jeff Layton <jlayton@redhat.com>
CC: Shirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
In preparation for Jeff's big umount/mount fixes to remove the possibility of
various races in cifs mount and linked list handling of sessions, sockets and
tree connections, this patch cleans up some repetitive code in cifs_mount,
and addresses a problem with ses->status and tcon->tidStatus in which we
were overloading the "need_reconnect" state with other status in that
field. So the "need_reconnect" flag has been broken out from those
two state fields (need reconnect was not mutually exclusive from some of the
other possible tid and ses states). In addition, a few exit cases in
cifs_mount were cleaned up, and a problem with a tcon flag (for lease support)
was not being set consistently for the 2nd mount of the same share
CC: Jeff Layton <jlayton@redhat.com>
CC: Shirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
When retrying kernel_recvmsg, reset iov_base and iov_len.
Note comment from Sridhar: "In the normal path, iov.iov_len is clearly set to 4. But i think you are
running into a case where kernel_recvmsg() is called via 'goto incomplete_rcv'
It happens if the previous call fails with EAGAIN.
If you want to call recvmsg() after EAGAIN failure, you need to reset iov."
Signed-off-by: Shirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
cifs: fix renaming one hardlink on top of another
POSIX says that renaming one hardlink on top of another to the same
inode is a no-op. We had the logic mostly right, but forgot to clear
the return code.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
smb_send2 exit logic was strange, and with the previous change
could cause us to fail large
smb writes when all of the smb was not sent as one chunk.
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
CIFS in some heavy stress conditions cifs could get EAGAIN
repeatedly in smb_send2 which led to repeated retries and eventually
failure of large writes which could lead to data corruption.
There are three changes that were suggested by various network
developers:
1) convert cifs from non-blocking to blocking tcp sendmsg
(we left in the retry on failure)
2) change cifs to not set sendbuf and rcvbuf size for the socket
(let tcp autotune the buffer sizes since that works much better
in the TCP stack now)
3) if we have a partial frame sent in smb_send2, mark the tcp
session as invalid (close the socket and reconnect) so we do
not corrupt the remaining part of the SMB with the beginning
of the next SMB.
This does not appear to hurt performance measurably and has
been run in various scenarios, but it definately removes
a corruption that we were seeing in some high stress
test cases.
Acked-by: Shirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
cifs: handle the TCP_Server_Info->tsk field more carefully
cifs: fix unlinking of rename target when server doesn't support open file renames
[CIFS] improve setlease handling
[CIFS] fix saving of resume key before CIFSFindNext
cifs: make cifs_rename handle -EACCES errors
[CIFS] fix build error
[CIFS] undo changes in cifs_rename_pending_delete if it errors out
cifs: track DeletePending flag in cifsInodeInfo
cifs: don't use CREATE_DELETE_ON_CLOSE in cifs_rename_pending_delete
[CIFS] eliminate usage of kthread_stop for cifsd
[CIFS] Add nodfs mount option
For execute permission on a regular files we need to check if file has
any execute bits at all, regardless of capabilites.
This check is normally performed by generic_permission() but was also
added to the case when the filesystem defines its own ->permission()
method. In the latter case the filesystem should be responsible for
performing this check.
Move the check from inode_permission() inside filesystems which are
not calling generic_permission().
Create a helper function execute_ok() that returns true if the inode
is a directory or if any execute bits are present in i_mode.
Also fix up the following code:
- coda control file is never executable
- sysctl files are never executable
- hfs_permission seems broken on MAY_EXEC, remove
- hfsplus_permission is eqivalent to generic_permission(), remove
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
With this patch all directory fops instances that have a readdir
that doesn't take the BKL are switched to generic_file_llseek.
Signed-off-by: Christoph Hellwig <hch@lst.de>
cifs: handle the TCP_Server_Info->tsk field more carefully
We currently handle the TCP_Server_Info->tsk field without any locking,
but with some half-measures to try and prevent races. These aren't
really sufficient though. When taking down cifsd, use xchg() to swap
the contents of the tsk field with NULL so we don't end up trying
to send it more than one signal. Also, don't allow cifsd to exit until
the signal is received if we expect one.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
cifs: fix unlinking of rename target when server doesn't support open file renames
The patch to make cifs_rename undoable broke renaming one file on top of
another when the server doesn't support busy file renames. Remove the
code that uses busy file renames to unlink the target file, and just
have it call cifs_unlink. If the rename of the source file fails, then
the unlink won't be undoable, but hopefully that's rare enough that it
won't be a problem.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
fcntl(F_SETLEASE) currently is not exported by cifs (nor by local file
systems) so cifs grants leases based on how other local processes have
opened the file not by whether the file is cacheable (oplocked). This
adds the check to make sure that the file is cacheable on the client
before checking whether we can grant the lease locally
(generic_setlease). It also adds a mount option for cifs (locallease)
if the user wants to override this and try to grant leases even
if the server did not grant oplock.
Signed-off-by: Steve French <sfrench@us.ibm.com>
We recently fixed the cifs readdir code so that it saves the resume key
before calling CIFSFindNext. Unfortunately, this assumes that we have
just done a CIFSFindFirst (or FindNext) and have resume info to save.
This isn't necessarily the case. Fix the code to save resume info if we
had to reinitiate the search, and after a FindNext.
This fixes connectathon basic test6 against NetApp filers.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
CC: Stable <stable@kernel.org>
Signed-off-by: Steve French <sfrench@us.ibm.com>
cifs: make cifs_rename handle -EACCES errors
Some servers seem to return -EACCES when attempting to rename one
open file on top of another. Refactor the cifs_rename logic to
attempt to rename the target file out of the way in this situation.
This also fixes the "unlink_target" logic to be undoable if the
subsequent rename fails.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Split the LRU lists in two, one set for pages that are backed by real file
systems ("file") and one for pages that are backed by memory and swap
("anon"). The latter includes tmpfs.
The advantage of doing this is that the VM will not have to scan over lots
of anonymous pages (which we generally do not want to swap out), just to
find the page cache pages that it should evict.
This patch has the infrastructure and a basic policy to balance how much
we scan the anon lists and how much we scan the file lists. The big
policy changes are in separate patches.
[lee.schermerhorn@hp.com: collect lru meminfo statistics from correct offset]
[kosaki.motohiro@jp.fujitsu.com: prevent incorrect oom under split_lru]
[kosaki.motohiro@jp.fujitsu.com: fix pagevec_move_tail() doesn't treat unevictable page]
[hugh@veritas.com: memcg swapbacked pages active]
[hugh@veritas.com: splitlru: BDI_CAP_SWAP_BACKED]
[akpm@linux-foundation.org: fix /proc/vmstat units]
[nishimura@mxp.nes.nec.co.jp: memcg: fix handling of shmem migration]
[kosaki.motohiro@jp.fujitsu.com: adjust Quicklists field of /proc/meminfo]
[kosaki.motohiro@jp.fujitsu.com: fix style issue of get_scan_ratio()]
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The cifs_rename_pending_delete process involves multiple steps. If it
fails and we're going to return error, we don't want to leave things in
a half-finished state. Add code to the function to undo changes if
a call fails.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
cifs: track DeletePending flag in cifsInodeInfo
The QPathInfo call returns a flag that indicates whether DELETE_ON_CLOSE
is set. Track it in the cifsInodeInfo.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
cifs: don't use CREATE_DELETE_ON_CLOSE in cifs_rename_pending_delete
CREATE_DELETE_ON_CLOSE apparently has different semantics than when you
set the DELETE_ON_CLOSE bit after opening the file. Setting it in the
open says "delete this file as soon as this filehandle is closed". That's
not what we want for cifs_rename_pending_delete.
Don't set this bit in the CreateFlags. Experimentation shows that
setting this flag in the SET_FILE_INFO call has no effect.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
When cifs_demultiplex_thread was converted to a kthread based kernel
thread, great pains were taken to make it so that kthread_stop would be
used to bring it down. This just added unnecessary complexity since we
needed to use a signal anyway to break out of kernel_recvmsg.
Also, cifs_demultiplex_thread does a bit of cleanup as it's exiting, and
we need to be certain that this gets done. It's possible for a kthread
to exit before its main function is ever run if kthread_stop is called
soon after its creation. While I'm not sure that this is a real problem
with cifsd now, it could be at some point in the future if cifs_mount is
ever changed to bring down the thread quickly.
The upshot here is that using kthread_stop to bring down the thread just
adds extra complexity with no real benefit. This patch changes the code
to use the original method to bring down the thread, but still leaves it
so that the thread is actually started with kthread_run.
This seems to fix the deadlock caused by the reproducer in this bug
report:
https://bugzilla.samba.org/show_bug.cgi?id=5720
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Older samba server (eg. 3.0.24 from Debian etch) don't work correctly,
if DFS paths are used. Such server claim that they support DFS, but fail
to process some requests with DFS paths. Starting with Linux 2.6.26,
the cifs clients starts sending DFS paths in such situations, rendering
it unuseable with older samba servers.
The nodfs mount options forces a share to be used with non DFS paths,
even if the server claims, that it supports it.
Signed-off-by: Martin Koegler <mkoegler@auto.tuwien.ac.at>
Acked-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Igor Mammedov <niallain@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
We lock GlobalMid_Lock in header_assemble and then immediately unlock it
again without doing anything. Not sure what this was intended to do, but
remove it.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Jeff's recent patch to add a last_entry field in the search structure
to better construct resume keys did not validate that the server
sent us a plausible pointer to the last entry. This adds that.
Signed-off-by: Steve French <sfrench@us.ibm.com>
When we do a seekdir() or equivalent, we usually end up doing a
FindFirst call and then call FindNext until we get to the offset that we
want. The problem is that when we call FindNext, the code usually
doesn't have the proper info (mostly, the filename of the entry from the
last search) to resume the search.
Add a "last_entry" field to the cifs_search_info that points to the last
entry in the search. We calculate this pointer by using the
LastNameOffset field from the search parms that are returned. We then
use that info to do a cifs_save_resume_key before we call CIFSFindNext.
This patch allows CIFS to reliably pass the "telldir" connectathon test.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
CC: Stable <stable@kernel.org>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Currently, if a standard delete fails and we end up getting -EACCES
we try to clear ATTR_READONLY and try the delete again. If that
then fails with -ETXTBSY then we try a rename_pending_delete. We
aren't handling other errors appropriately though.
Another client could have deleted the file in the meantime and
we get back -ENOENT, for instance. In that case we wouldn't do a
d_drop. Instead of retrying in a separate call, simply goto the
original call and use the error handling from that.
Also, we weren't properly undoing any attribute changes that
were done before returning an error back to the caller.
CC: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
We only need to set them when we call SetFileInfo or SetPathInfo
directly, and as soon as possible after then. We had one place setting
it where it didn't need to be, and another place where it was missing.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
cifs: explicitly revoke SPNEGO key after session setup
The SPNEGO blob returned by an upcall can only be used once. Explicitly
revoke it to make sure that we never pick it up again after session
setup exits.
This doesn't seem to be that big an issue on more recent kernels, but
older kernels seem to link keys into the session keyring by default.
That said, explicitly revoking the key seems like a reasonable thing
to do here.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
cifs: Convert cifs to new aops.
This patch is based on the one originally posted by Nick Piggin. His
patch was very close, but had a couple of small bugs. Nick's original
comments follow:
This is another relatively naive conversion. Always do the read upfront
when the page is not uptodate (unless we're in the writethrough path).
Fix an uninitialized data exposure where SetPageUptodate was called
before the page was uptodate.
SetPageUptodate and switch to writeback mode in the case that the full
page was dirtied.
Acked-by: Shaggy <shaggy@austin.ibm.com>
Acked-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
cifs: remove NULL termination from rename target in CIFSSMBRenameOpenFIle
The rename destination isn't supposed to be null terminated. Also,
change the name string arg to be const.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
cifs: work around samba returning -ENOENT on SetFileDisposition call
Samba seems to return STATUS_OBJECT_NAME_NOT_FOUND when we try to set
the delete on close bit after doing a rename by filehandle. This looks
like a samba bug to me, but a lot of servers will do this. For now,
pretend an -ENOENT return is a success.
Samba does however seem to respect the CREATE_DELETE_ON_CLOSE bit
when opening files that already exist. Windows will ignore it, but
so adding it to the open flags should be harmless.
We're also currently ignoring the return code on the rename by
filehandle, so no need to set rc based on it.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
We're given the datalen in the downcall, so there's no need to do any
calls to strlen(). Just keep track of the datalen in the key. Finally,
add a sanity check of the data in the downcall to make sure that it
looks like a real IP address.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Break out the code that does the actual renaming into a separate
function and have cifs_rename call that. That function will attempt a
path based rename first and then do a filehandle based one if it looks
like the source is busy.
The existing logic tried a path based rename first, but if we needed to
remove the destination then it only attempted a filehandle based rename
afterward. Not all servers support renaming by filehandle, so we need to
always attempt path rename first and fall back to filehandle rename if
it doesn't work.
This also fixes renames of open files on windows servers (at least when
the source and destination directories are the same).
CC: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
cifs: add function to set file disposition
The proper way to set the delete on close bit on an already existing
file is to use SET_FILE_INFO with an infolevel of
SMB_FILE_DISPOSITION_INFO. Add a function to do that and have the
silly-rename code use it.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
cifs: move rename and delete-on-close logic into helper function
When a file is still open on the server, we attempt to set the
DELETE_ON_CLOSE bit and rename it to a new filename. When the
last opener closes the file, the server should delete it.
This patch moves this mechanism into a helper function and has
the two places in cifs_unlink that do this procedure call it. It
also fixes the open flags to be correct.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
When the CIFS client goes to write out pages, it needs to pick a
filehandle to write to. find_writeable_file however just picks the
first filehandle that it finds. This can cause problems when a lock
is issued against a particular filehandle and we pick a different
filehandle to write to.
This patch tries to avert this situation by having find_writable_file
prefer filehandles that have a pid that matches the current task.
This seems to fix lock test 11 from the connectathon test suite when
run against a windows server.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
GFP_KERNEL and GFP_NOFS are mutually exclusive. If you combine them, you end up
with plain GFP_KERNEL which can deadlock in cases where you really want
GFP_NOFS.
Cc: Steve French <sfrench@samba.org>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Steve French <sfrench@us.ibm.com>
We already have a cifs_set_file_info function that can flip DOS
attribute bits. Have cifs_unlink call it to handle turning ATTR_HIDDEN
on and ATTR_READONLY off when an unlink attempt returns -EACCES.
This also removes a level of indentation from cifs_unlink.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Change parameters to cifs_unlink to match the ones used in the generic
VFS. Add some local variables to cut down on the amount of struct
dereferencing that needs to be done, and eliminate some unneeded NULL
pointer checks on the parent directory inode. Finally, rename pTcon
to "tcon" to more closely match standard kernel coding style.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
LANMAN session setup did not support Unicode (after session setup, unicode can
still be used though).
Fixes samba bug# 5319
CC: Jeff Layton <jlayton@redhat.com>
CC: Stable Kernel <stable@vger.kernel.org>
Signed-off-by: Steve French <sfrench@us.ibm.com>
The direct I/O write codepath for CIFS is done through
cifs_user_write(). That function does not currently call
generic_write_checks() so the file position isn't being properly set
when the file is opened with O_APPEND. It's also not doing the other
"normal" checks that should be done for a write call.
The problem is currently that when you open a file with O_APPEND on a
mount with the directio mount option, the file position is set to the
beginning of the file. This makes any subsequent writes clobber the data
in the file starting at the beginning.
This seems to fix the problem in cursory testing. It is, however
important to note that NFS disallows the combination of
(O_DIRECT|O_APPEND). If my understanding is correct, the concern is
races with multiple clients appending to a file clobbering each others'
data. Since the write model for CIFS and NFS is pretty similar in this
regard, CIFS is probably subject to the same sort of races. What's
unclear to me is why this is a particular problem with O_DIRECT and not
with buffered writes...
Regardless, disallowing O_APPEND on an entire mount is probably not
reasonable, so we'll probably just have to deal with it and reevaluate
this flag combination when we get proper support for O_DIRECT. In the
meantime this patch at least fixes the existing problem.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: Steve French <sfrench@us.ibm.com>
The last eight bytes of the password field were not cleared when doing lanman plaintext password authentication. This patch fixes that.
I tested it with Samba by setting password
encryption to no in the server's smb.conf. Other servers also can be
configured to force plaintext authentication. Note that plaintexti
authentication requires setting /proc/fs/cifs/SecurityFlags to 0x30030
on the client (enabling both LANMAN and also plaintext password support).
Also note that LANMAN support (and thus plaintext password support) requires
CONFIG_CIFS_WEAK_PW_HASH to be enabled in menuconfig.
CC: Jeff Layton <jlayton@redhat.com>
CC: Stable Kernel <stable@vger.kernel.org>
Signed-off-by: Steve French <sfrench@us.ibm.com>
