CIFS currently allows you to change the mode of an inode on a share that
doesn't have unix extensions enabled, and isn't using cifsacl. The inode
in this case *only* has its mode changed in memory on the client. This
is problematic since it can change any time the inode is purged from the
cache.
This patch makes cifs_setattr silently ignore most mode changes when
unix extensions and cifsacl support are not enabled, and when the share
is not mounted with the "dynperm" option. The exceptions are:
When a mode change would remove all write access to an inode we turn on
the ATTR_READONLY bit on the server and remove all write bits from the
inode's mode in memory.
When a mode change would add a write bit to an inode that previously had
them all turned off, it turns off the ATTR_READONLY bit on the server,
and resets the mode back to what it would normally be (generally, the
file_mode or dir_mode of the share).
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
CIFS currently allows you to change the ownership of a file, but unless
unix extensions are enabled this change is not passed off to the server.
Have CIFS silently ignore ownership changes that can't be persistently
stored on the server unless the "setuids" option is explicitly
specified.
We could return an error here (-EOPNOTSUPP or something), but this is
how most disk-based windows filesystems on behave on Linux (e.g. VFAT,
NTFS, etc). With cifsacl support and proper Windows to Unix idmapping
support, we may be able to do this more properly in the future.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
When CIFS creates a new inode on a mount without unix extensions, it
temporarily assigns the mode that was passed to it in the create/mkdir
call. Eventually, when the inode is revalidated, it changes to have the
file_mode or dir_mode for the mount. This is confusing to users who
expect that the mode shouldn't change this way. It's also problematic
since only the mode is treated this way, not the uid or gid. Suppose you
have a CIFS mount that's mounted with:
uid=0,gid=0,file_mode=0666,dir_mode=0777
...if an unprivileged user comes along and does this on the mount:
mkdir -m 0700 foo
touch foo/bar
...there is a period of time where the touch will fail, since the dir
will initially be owned by root and have mode 0700. If the user waits
long enough, then "foo" will be revalidated and will get the correct
dir_mode permissions.
This patch changes cifs_mkdir and cifs_create to not overwrite the
mode found by the initial cifs_get_inode_info call after the inode is
created on the server. Legacy behavior can be reenabled with the
new "dynperm" mount option.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
When mounting a share with posix extensions disabled,
cifs_get_inode_info turns off all the write bits in the mode for regular
files if ATTR_READONLY is set. Directories and other inode types,
however, can also have ATTR_READONLY set, but the mode gives no
indication of this.
This patch makes this apply to other inode types besides regular files.
It also cleans up how modes are set in cifs_get_inode_info for both the
"normal" and "dynperm" cases.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Final piece for handling DFS in query_path_info, constructing a
fake inode for the junction directory which the submount will cover.
This handles the non-Unix (Windows etc.) code path.
Signed-off-by: Steve French <sfrench@us.ibm.com>
Final piece for handling DFS in unix_query_path_info, constructing a
fake inode for the junction directory which the submount will cover.
Acked-by: Igor Mammedov <niallain@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Also Kari Hurtta noticed a missing check in the same function which is now fixed.
CC: Kari Hurtta <hurtta+gmane@siilo.fmi.fi>
Signed-off-by: Steve French <sfrench@us.ibm.com>
adds various options to cifs_show_options
(displayed when you cat /proc/mounts with a cifs mount). I limited
the new ones to values that are associated with the mount with the
exception of "seal" (which is a per tree connection property, but I
thought was important enough to show through).
Eventually cifs's parse_mount_options also needs to
be rewritten to use the match_token API but that would be a big enough
change that I would prefer that changing parse_mount_options wait
until next release.
Signed-off-by: Steve French <sfrench@us.ibm.com>
Samba now supports transport encryption on particular exports
(mounted tree ids can be encrypted for servers which support the
unix extensions). This adds parsing support to cifs mount
option parsing for this.
Signed-off-by: Steve French <sfrench@us.ibm.com>
cifs_ioctl doesn't seem to need the BKL for anything, so convert it over
to use unlocked_ioctl.
Signed-off-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Steve French <sfrench@us.ibm.com>
fs/cifs/dir.c: In function 'cifs_ci_compare':
fs/cifs/dir.c:582: warning: passing argument 1 of 'memcpy' discards
qualifiers from pointer target type
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Some versions of Samba (3.2-pre e.g.) are stricter about checking to make sure that
paths in DFS name spaces are sent in the form \\server\share\dir\subdir ...
instead of \dir\subdir
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
SMBLegacyOpen always opens a file as r/w. This could be problematic
for files with ATTR_READONLY set. Have it interpret the access_mode
into a sane open mode.
Signed-off-by: Steve French <sfrench@us.ibm.com>
cifs_convert_flags returns 0x20197 in the default case. It's not
immediately evident where that number comes from, so change it
to be an or'ed set of flags. The compiler will boil it down anyway.
(Thanks to Guenter Kukkukk for clarifying the flags).
Signed-off-by: Steve French <sfrench@us.ibm.com>
Do the following series of operations on a CIFS share:
opendir(dir)
readdir(dir)
unlink(file in dir)
rewinddir(dir)
readdir(dir)
If the readdir read all entries in the directory this will make CIFS throw an error like this:
CIFS VFS: Send error in FindClose = -9
CIFS requests "Close at end of search" of the server by setting this bit when issuing FindFirst or FindNext. Therefore when all search entries are returned, the server may return "end of search" and close the search implicitly when this bit is set by the client on the request. We check for this when a readdir is explicitly closed - but when the client notices that a directory has changed after the last operation, we attempt to close the directory before reopening by reissuing a second FindFirst. But, the directory may already been implicitly closed (due to end of search) because the first readdir finished. So we only want to issue a FindClose call in this case when we don't expect it to already be closed.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
all other codepaths in this function return negative values on errors
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
When CIFSFindNext gets back an -EBADF from a call, it sets the return
code of the function to 0 and eventually exits. Doing this makes the
cleanup at the end of the function skip freeing the SMB buffer, so
we need to make sure we free the buffer explicitly when doing this.
If we don't you end up with errors like this when unplugging the cifs
kernel module:
slab error in kmem_cache_destroy(): cache `cifs_request': Can't free all objects
[<c046bdbf>] kmem_cache_destroy+0x61/0xf3
[<e0f03045>] cifs_destroy_request_bufs+0x14/0x28 [cifs]
[<e0f2016e>] exit_cifs+0x1e/0x80 [cifs]
[<c043aeae>] sys_delete_module+0x192/0x1b8
[<c04451fd>] audit_syscall_entry+0x14b/0x17d
[<c0405413>] syscall_call+0x7/0xb
=======================
Signed-off-by: Jeff Layton <jlayton@redhat.com>
when unix extensions and cifsacl support are disabled. These
permissions changes are "ephemeral" however. They are lost whenever
a share is mounted and unmounted, or when memory pressure forces
the inode out of the cache.
Because of this, we'd like to introduce a behavior change to make
CIFS behave more like local DOS/Windows filesystems. When unix
extensions and cifsacl support aren't enabled, then don't silently
ignore changes to permission bits that can't be reflected on the
server.
Still, there may be people relying on the current behavior for
certain applications. This patch adds a new "dynperm" (and a
corresponding "nodynperm") mount option that will be intended
to make the client fall back to legacy behavior when setting
these modes.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
cifs_demultiplex_thread can exit under several conditions:
1) if it's signaled
2) if there's a problem with session setup
3) if kthread_stop is called on it
The first two are problems. If kthread_stop is called on the thread,
there is no guarantee that it will still be up. We need to have the
thread stay up until kthread_stop is called on it.
One option would be to not even try to tear things down until after
kthread_stop is called. However, in the case where there is a problem
setting up the session, there's no real reason to try continuing the
loop.
This patch allows the thread to clean up and prepare for exit under all
three conditions, but it has the thread go to sleep until kthread_stop
is called. This allows us to simplify the shutdown code somewhat since
we can be reasonably sure that the thread won't exit after being
signaled but before kthread_stop is called.
It also removes the places where the thread itself set the tsk variable
since it appeared that it could have a potential race where the thread
might never be shut down.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Steve French <sfrench@us.ibm.com>
When creating a directory on a CIFS share without POSIX extensions,
and the given mode has no write bits set, set the ATTR_READONLY bit.
When creating a file, set ATTR_READONLY if the create mode has no write
bits set and we're not using unix extensions.
There are some comments about this being problematic due to the VFS
splitting creates into 2 parts. I'm not sure what that's actually
talking about, but I'm assuming that it has something to do with how
mknod is implemented. In the simple case where we have no unix
extensions and we're just creating a regular file, there's no reason
we can't set ATTR_READONLY.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Clean up cifs_setattr a bit by adding a local inode pointer, and
changing all of the direntry->d_inode references to it. This also adds a
bit of micro-optimization. d_inode shouldn't change over the life of
this function, so we only need to dereference it once.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
This patch cleans up cifs_find_tcp_session so it become
less indented. Also the error of skipping IPv6 matched
addresses fixed.
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Was a holdover from the old kernel_thread based cifsd
code. We needed to know that the thread had set the task variable
before proceeding. Now that kthread_run returns the new task, this
doesn't appear to be needed anymore.
As best I can tell, this sleep was intended to try to prevent
cifs_umount from freeing the cifsSesInfo struct before cifsd had
exited. Now that cifsd is using the kthread API, we know that
when kthread_stop returns that cifsd has exited, so I don't
think this is needed any longer.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Christop Hellwig <hch@infradead.org>
Signed-off-by: Steve French <sfrench@us.ibm.com>
The current logic in cifs_setattr calls mode_to_acl twice on mode
changes if cifsacl is enabled. Remove the duplicate call.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
CC: Shirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Use creation by full path instead: "fs/foo".
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
treeName part is canonicalized to '/' path separator
Signed-off-by: Igor Mammedov <niallain@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
