Make CIFS use the new d_automount() dentry operation rather than abusing
follow_link() on directories.

[NOTE: THIS IS UNTESTED!]
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Cc: Steve French <sfrench@samba.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Reduce false inode collisions by using the CreationTime like an
i_generation field. This way, even if the server ends up reusing
a uniqueid after a delete/create cycle, we can avoid matching
the inode incorrectly.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

dcache_inode_lock can be replaced with per-inode locking. Use existing
inode->i_lock for this. This is slightly non-trivial because we sometimes
need to find the inode from the dentry, which requires d_inode to be
stabilised (either with refcount or d_lock).
Signed-off-by: NNick Piggin <npiggin@kernel.dk>

Reduce some branches and memory accesses in dcache lookup by adding dentry
flags to indicate common d_ops are set, rather than having to check them.
This saves a pointer memory access (dentry->d_op) in common path lookup
situations, and saves another pointer load and branch in cases where we
have d_op but not the particular operation.

Patched with:

git grep -E '[.>]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)->d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&\1, \2);/' -i
Signed-off-by: NNick Piggin <npiggin@kernel.dk>

dcache_lock no longer protects anything. remove it.
Signed-off-by: NNick Piggin <npiggin@kernel.dk>

Add a new lock, dcache_inode_lock, to protect the inode's i_dentry list
from concurrent modification. d_alias is also protected by d_lock.
Signed-off-by: NNick Piggin <npiggin@kernel.dk>

It's possible that cifs_mount will call cifs_build_path_to_root on a
newly instantiated cifs_sb. In that case, it's likely that the
master_tlink pointer has not yet been instantiated.

Fix this by having cifs_build_path_to_root take a cifsTconInfo pointer
as well, and have the caller pass that in.
Reported-and-Tested-by: NRobbert Kouprie <robbert@exx.nl>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Some of the code under CONFIG_CIFS_ACL is dependent upon code under
CONFIG_CIFS_EXPERIMENTAL, but the Kconfig options don't reflect that
dependency. Move more of the ACL code out from under
CONFIG_CIFS_EXPERIMENTAL and under CONFIG_CIFS_ACL.

Also move find_readable_file out from other any sort of Kconfig
option and make it a function normally compiled in.
Reported-and-Acked-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Currently, the attribute cache timeout for CIFS is hardcoded to 1 second. This
means that the client might have to issue a QPATHINFO/QFILEINFO call every 1
second to verify if something has changes, which seems too expensive. On the
other hand, if the timeout is hardcoded to a higher value, workloads that
expect strict cache coherency might see unexpected results.

Making attribute cache timeout as a tunable will allow us to make a tradeoff
between performance and cache metadata correctness depending on the
application/workload needs.

Add 'actimeo' tunable that can be used to tune the attribute cache timeout.
The default timeout is set to 1 second. Also, display actimeo option value in
/proc/mounts.

It appears to me that 'actimeo' and the proposed (but not yet merged)
'strictcache' option cannot coexist, so care must be taken that we reset the
other option if one of them is set.

Changes since last post:
   - fix option parsing and handle possible values correcly
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSuresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Change the name of function mode_to_acl to mode_to_cifs_acl.

Handle return code in functions mode_to_cifs_acl and
cifs_acl_to_fattr.
Signed-off-by: NShirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Only the callers check whether the invalid_mapping flag is set and not
cifs_invalidate_mapping().
Signed-off-by: NSuresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

cifs_root_iget allocates full_path through
cifs_build_path_to_root, but fails to kfree it upon
cifs_get_inode_info* failure.

Make all failure exit paths traverse clean up
handling at the end of the function.
Signed-off-by: NOskar Schirmer <oskar@scara.com>
Reviewed-by: NJesper Juhl <jj@chaosbits.net>
Cc: stable@kernel.org
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Andrew Hendry reported a kmemleak warning in 2.6.37-rc1 while editing a
text file with gedit over cifs.

unreferenced object 0xffff88022ee08b40 (size 32):
  comm "gedit", pid 2524, jiffies 4300160388 (age 2633.655s)
  hex dump (first 32 bytes):
    5c 2e 67 6f 75 74 70 75 74 73 74 72 65 61 6d 2d  \.goutputstream-
    35 42 41 53 4c 56 00 de 09 00 00 00 2c 26 78 ee  5BASLV......,&x.
  backtrace:
    [<ffffffff81504a4d>] kmemleak_alloc+0x2d/0x60
    [<ffffffff81136e13>] __kmalloc+0xe3/0x1d0
    [<ffffffffa0313db0>] build_path_from_dentry+0xf0/0x230 [cifs]
    [<ffffffffa031ae1e>] cifs_setattr+0x9e/0x770 [cifs]
    [<ffffffff8115fe90>] notify_change+0x170/0x2e0
    [<ffffffff81145ceb>] sys_fchmod+0x10b/0x140
    [<ffffffff8100c172>] system_call_fastpath+0x16/0x1b
    [<ffffffffffffffff>] 0xffffffffffffffff

The commit 1025774c that removed inode_setattr() seems to have introduced this
memleak by returning early without freeing 'full_path'.
Reported-by: NAndrew Hendry <andrew.hendry@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSuresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

write_behind_rc is redundant and just adds complexity to the code. What
we really want to do instead is to use mapping_set_error to reset the
flags on the mapping when we find a writeback error and can't report it
to userspace yet.

For cifs_flush and cifs_fsync, we shouldn't reset the flags since errors
returned there do get reported to userspace.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Reviewed-by: NSuresh Jayaraman <sjayaraman@suse.de>
Reviewed-by: NDave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

commit 3aa1c8c2 made cifs_getattr set
the ownership of files to current_fsuid/current_fsgid when multiuser
mounts were in use and when mnt_uid/mnt_gid were non-zero.

It should have instead based that decision on the
CIFS_MOUNT_OVERR_UID/GID flags.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

...when unix extensions aren't enabled. This makes everything on the
mount appear to be owned by the current user.

This version of the patch differs from previous versions however in that
the admin can still force the ownership of all files to appear as a
single user via the uid=/gid= options.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

When we implement multiuser mounts, we'll need to filter filehandles
by fsuid. Add a flag for multiuser mounts and code to filter by
fsuid when it's set.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

cifsFileInfo needs a pointer to a tcon, but it doesn't currently hold a
reference to it. Change it to keep a pointer to a tcon_link instead and
hold a reference to it.

That will keep the tcon from being freed until the file is closed.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Eventually, we'll need to track the use of tcons on a per-sb basis, so that
we know when it's ok to tear them down. Begin this conversion by adding a
new "tcon_link" struct and accessors that get it. For now, the core data
structures are untouched -- cifs_sb still just points to a single tcon and
the pointers are just cast to deal with the accessor functions. A later
patch will flesh this out.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Testing on very recent kernel (2.6.36-rc6) made this warning pop:

    WARNING: at fs/fs-writeback.c:87 inode_to_bdi+0x65/0x70()
    Hardware name:
    Dirtiable inode bdi default != sb bdi cifs

...the following patch fixes it and seems to be the obviously correct
thing to do for cifs.

Cc: stable@kernel.org
Acked-by: NDave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

At mount time, we'll always need to create a tcon that will serve as a
template for others that are associated with the mount. This tcon is
known as the "master" tcon.

In some cases, we'll need to use that tcon regardless of who's accessing
the mount. Add an accessor function for the master tcon and go ahead and
switch the appropriate places to use it.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

When we convert cifs to do multiple sessions per mount, we'll need more
than one tcon per superblock. At that point "cifs_sb->tcon" will make
no sense. Add a new accessor function that gets a tcon given a cifs_sb.
For now, it just returns cifs_sb->tcon. Later it'll do more.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

...where it's available and appropriate.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

If configured, Minshall+French Symlinks are used against
all servers. If the server supports UNIX Extensions,
we still create Minshall+French Symlinks on write,
but on read we fallback to UNIX Extension symlinks.
Signed-off-by: NStefan Metzmacher <metze@samba.org>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

The VFS always checks that the source and target of a rename are on the
same vfsmount, and hence have the same superblock. So, this check is
redundant. Remove it and simplify the error handling.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

On 08/26/2010 01:56 AM, joe hefner wrote:
> On a recent Fedora (13), I am seeing a mount failure message that I can not explain. I have a Windows Server 2003ýa with a share set up for access only for a specific username (say userfoo). If I try to mount it from Linux,ýusing userfoo and the correct password all is well. If I try with a bad password or with some other username (userbar), it fails with "Permission denied" as expected. If I try to mount as username = administrator, and give the correct administrator password, I would also expect "Permission denied", but I see "Cannot allocate memory" instead.

> ýfs/cifs/netmisc.c: Mapping smb error code 5 to POSIX err -13
> ýfs/cifs/cifssmb.c: Send error in QPathInfo = -13
> ýCIFS VFS: cifs_read_super: get root inode failed

Looks like the commit 0b8f18e3 assumed that cifs_get_inode_info() and
friends fail only due to memory allocation error when the inode is NULL
which is not the case if CIFSSMBQPathInfo() fails and returns an error.
Fix this by propagating the actual error code back.
Acked-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSuresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Remove the calls to inode_newsize_ok given that we already did it as
part of inode_change_ok in the beginning of cifs_setattr_(no)unix.

No need to call ->truncate if cifs doesn't have one, so remove the
explicit call in cifs_vmtruncate, and replace the calls to vmtruncate
with truncate_setsize which is vmtruncate minus inode_newsize_ok
and the call to ->truncate.

Rename cifs_vmtruncate to cifs_setsize to match the new calling conventions.

Question 1:  why does cifs do the pagecache munging and i_size update twice
	for each setattr call, once opencoded in cifs_vmtruncate, and once
	using the VFS helpers?
Question 2: what is supposed to be protected by i_lock in cifs_vmtruncate?
	Do we need it around the call to inode_change_ok?

[AV: fixed build breakage]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Make sure we call inode_change_ok before doing any changes in ->setattr,
and make sure to call it even if our fs wants to ignore normal UNIX
permissions, but use the ATTR_FORCE to skip those.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Replace inode_setattr with opencoded variants of it in all callers.  This
moves the remaining call to vmtruncate into the filesystem methods where it
can be replaced with the proper truncate sequence.

In a few cases it was obvious that we would never end up calling vmtruncate
so it was left out in the opencoded variant:

 spufs: explicitly checks for ATTR_SIZE earlier
 btrfs,hugetlbfs,logfs,dlmfs: explicitly clears ATTR_SIZE earlier
 ufs: contains an opencoded simple_seattr + truncate that sets the filesize just above

In addition to that ncpfs called inode_setattr with handcrafted iattrs,
which allowed to trim down the opencoded variant.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

It turns out that not all directory inodes with dentries on the
i_dentry list are unusable here. We only consider them unusable if they
are still hashed or if they have a root dentry attached.

Full disclosure -- this check is inherently racy. There's nothing that
stops someone from slapping a new dentry onto this inode just after
this check, or hashing an existing one that's already attached. So,
this is really a "best effort" thing to work around misbehaving servers.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

If the type is different from what we think it should be, then don't
match the existing inode.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Signed-off-by: NSteve French <sfrench@us.ibm.com>

Define inode-level data storage objects (managed by cifsInodeInfo structs).
Each inode-level object is created in a super-block level object and is itself
a data storage object in to which pages from the inode are stored.

The inode object is keyed by UniqueId. The coherency data being used is
LastWriteTime, LastChangeTime and end of file reported by the server.
Signed-off-by: NSuresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Define superblock-level cache index objects (managed by cifsTconInfo structs).
Each superblock object is created in a server-level index object and in itself
an index into which inode-level objects are inserted.

The superblock object is keyed by sharename. The UniqueId/IndexNumber is used to
validate that the exported share is the same since we accessed it last time.
Signed-off-by: NSuresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Busy-file renames don't actually work across directories, so we need
to limit this code to renames within the same dir.

This fixes the bug detailed here:

    https://bugzilla.redhat.com/show_bug.cgi?id=591938Signed-off-by: NJeff Layton <jlayton@redhat.com>
CC: Stable <stable@kernel.org>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

The uniqueid field sent by the server when unix extensions are enabled
is currently used sometimes when it shouldn't be. The readdir codepath
is correct, but most others are not. Fix it.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

We use this value to find an inode within the hash bucket, so we can't
change this without re-hashing the inode. For now, treat this value
as immutable.

Eventually, we should probably use an inode number change on a path
based operation to indicate that the lookup cache is invalid, but that's
a bit more code to deal with.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

The old cifs_revalidate logic always revalidated hardlinked inodes.
This hack allowed CIFS to pass some connectathon tests when server inode
numbers aren't used (basic test7, in particular).
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>