This patch fixes the errors made in the users of the crypto layer during
the sg_init_table conversion.  It also adds a few conversions that were
missing altogether.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Most drivers need to set length and offset as well, so may as well fold
those three lines into one.

Add sg_assign_page() for those two locations that only needed to set
the page, where the offset/length is set outside of the function context.
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

The functions that eventually call down to ecryptfs_read_lower(),
ecryptfs_decrypt_page(), and ecryptfs_copy_up_encrypted_with_header()
should have the responsibility of managing the page Uptodate
status. This patch gets rid of some of the ugliness that resulted from
trying to push some of the page flag setting too far down the stack.
Signed-off-by: NMichael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Replace some magic numbers with sizeof() equivalents.
Signed-off-by: NMichael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The switch to read_write.c routines and the persistent file make a number of
functions unnecessary.  This patch removes them.
Signed-off-by: NMichael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Update data types and add casts in order to avoid potential overflow
issues.
Signed-off-by: NMichael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Rather than open a new lower file for every eCryptfs file that is opened,
truncated, or setattr'd, instead use the existing lower persistent file for
the eCryptfs inode.  Change truncate to use read_write.c functions.  Change
ecryptfs_getxattr() to use the common ecryptfs_getxattr_lower() function.
Signed-off-by: NMichael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Update the metadata read/write functions and grow_file() to use the
read_write.c routines.  Do not open another lower file; use the persistent
lower file instead.  Provide a separate function for
crypto.c::ecryptfs_read_xattr_region() to get to the lower xattr without
having to go through the eCryptfs getxattr.
Signed-off-by: NMichael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Replace page encryption and decryption routines and inode size write routine
with versions that utilize the read_write.c functions.
Signed-off-by: NMichael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove assignments in if-statements.
Signed-off-by: NMichael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There is no point to keeping a separate header_extent_size and an extent_size.
 The total size of the header can always be represented as some multiple of
the regular data extent size.

[randy.dunlap@oracle.com: ecryptfs: fix printk format warning]
Signed-off-by: NMichael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Andrew Morton wrote:
> Please check that all the newly-added global symbols do indeed need
> to be global.

Change symbols in keystore.c and crypto.o to static if they do not
need to be global.
Signed-off-by: NMichael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Andrew Morton wrote:
From: mhalcrow@us.ibm.com <mhalcrow@halcrow.austin.ibm.com>
> > +/**
> > + * decrypt_passphrase_encrypted_session_key - Decrypt the session key
> > + * with the given auth_tok.
> >   *
> >   * Returns Zero on success; non-zero error otherwise.
> >   */
>
> That comment purports to be a kerneldoc-style comment.  But
>
> - kerneldoc doesn't support multiple lines on the introductory line
>   which identifies the name of the function (alas).  So you'll need to
>   overflow 80 cols here.
>
> - the function args weren't documented
>
> But the return value is!  People regularly forget to do that.  And
> they frequently forget to document the locking prerequisites and the
> permissible calling contexts (process/might_sleep/hardirq, etc)
>
> (please check all ecryptfs kerneldoc for this stuff sometime)

This patch cleans up some of the existing comments and makes a couple
of line break tweaks. There is more work to do to bring eCryptfs into
full kerneldoc-compliance.
Signed-off-by: NMichael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Andrew Morton wrote:
> > +int ecryptfs_destruct_crypto(void)
>
> ecryptfs_destroy_crypto would be more grammatically correct ;)

Grammatical fix for some function names.
Signed-off-by: NMichael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Andrew Morton wrote:
> > +     crypt_stat->flags |= ECRYPTFS_ENCRYPTED;
> > +     crypt_stat->flags |= ECRYPTFS_KEY_VALID;
>
> Maybe the compiler can optimise those two statements, but we'd
> normally provide it with some manual help.

This patch provides the compiler with some manual help for
optimizing the setting of some flags.
Signed-off-by: NMichael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Andrew Morton wrote:
> > +     mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);
> > +     BUG_ON(mount_crypt_stat->num_global_auth_toks == 0);
> > +     mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex);
>
> That's odd-looking.  If it was a bug for num_global_auth_toks to be
> zero, and if that mutex protects num_global_auth_toks then as soon
> as the lock gets dropped, another thread can make
> num_global_auth_toks zero, hence the bug is present.  Perhaps?

That was serving as an internal sanity check that should not have made
it into the final patch set in the first place. This patch removes it.
Signed-off-by: NMichael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Trivial updates to comment and debug statement.
Signed-off-by: NMichael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add support structures for handling multiple keys.  The list in crypt_stat
contains the key identifiers for all of the keys that should be used for
encrypting each file's File Encryption Key (FEK).  For now, each inode
inherits this list from the mount-wide crypt_stat struct, via the
ecryptfs_copy_mount_wide_sigs_to_inode_sigs() function.

This patch also removes the global key tfm from the mount-wide crypt_stat
struct, instead keeping a list of tfm's meant for dealing with the various
inode FEK's.  eCryptfs will now search the user's keyring for FEK's parsed
from the existing file metadata, so the user can make keys available at any
time before or after mounting.

Now that multiple FEK packets can be written to the file metadata, we need to
be more meticulous about size limits.  The updates to the code for writing out
packets to the file metadata makes sizes and limits more explicit, uniformly
expressed, and (hopefully) easier to follow.
Signed-off-by: NMichael Halcrow <mhalcrow@us.ibm.com>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Open-code flag checking and manipulation.
Signed-off-by: NMichael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: NTrevor Highland <tshighla@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Replace kmap() with kmap_atomic().  Reduce the amount of time that mappings
are held.
Signed-off-by: NMichael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: NTrevor Highland <tshighla@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

sys_write() takes a local copy of f_pos and writes that back
into the struct file. It does this so that two concurrent write()
callers don't make a mess of f_pos, and of the file contents.

ecryptfs should be calling vfs_write().  That way we also get the fsnotify
notifications, which ecryptfs presently appears to have subverted.

Convert direct calls to f_op->write() into calls to vfs_write().
Signed-off-by: NMichael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Provide an option to provide a view of the encrypted files such that the
metadata is always in the header of the files, regardless of whether the
metadata is actually in the header or in the extended attribute.  This mode of
operation is useful for applications like incremental backup utilities that do
not preserve the extended attributes when directly accessing the lower files.

With this option enabled, the files under the eCryptfs mount point will be
read-only.
Signed-off-by: NMichael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Generalize the metadata reading and writing mechanisms, with two targets for
now: metadata in file header and metadata in the user.ecryptfs xattr of the
lower file.

[akpm@osdl.org: printk warning fix]
[bunk@stusta.de: make some needlessly global code static]
Signed-off-by: NMichael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch set introduces the ability to store cryptographic metadata into an
lower file extended attribute rather than the lower file header region.

This patch set implements two new mount options:

ecryptfs_xattr_metadata
 - When set, newly created files will have their cryptographic
   metadata stored in the extended attribute region of the file rather
   than the header.

   When storing the data in the file header, there is a minimum of 8KB
   reserved for the header information for each file, making each file at
   least 12KB in size.  This can take up a lot of extra disk space if the user
   creates a lot of small files.  By storing the data in the extended
   attribute, each file will only occupy at least of 4KB of space.

   As the eCryptfs metadata set becomes larger with new features such as
   multi-key associations, most popular filesystems will not be able to store
   all of the information in the xattr region in some cases due to space
   constraints.  However, the majority of users will only ever associate one
   key per file, so most users will be okay with storing their data in the
   xattr region.

   This option should be used with caution.  I want to emphasize that the
   xattr must be maintained under all circumstances, or the file will be
   rendered permanently unrecoverable.  The last thing I want is for a user to
   forget to set an xattr flag in a backup utility, only to later discover
   that their backups are worthless.

ecryptfs_encrypted_view
 - When set, this option causes eCryptfs to present applications a
   view of encrypted files as if the cryptographic metadata were
   stored in the file header, whether the metadata is actually stored
   in the header or in the extended attributes.

   No matter what eCryptfs winds up doing in the lower filesystem, I want
   to preserve a baseline format compatibility for the encrypted files.  As of
   right now, the metadata may be in the file header or in an xattr.  There is
   no reason why the metadata could not be put in a separate file in future
   versions.

   Without the compatibility mode, backup utilities would have to know to
   back up the metadata file along with the files.  The semantics of eCryptfs
   have always been that the lower files are self-contained units of encrypted
   data, and the only additional information required to decrypt any given
   eCryptfs file is the key.  That is what has always been emphasized about
   eCryptfs lower files, and that is what users expect.  Providing the
   encrypted view option will provide a way to userspace applications wherein
   they can always get to the same old familiar eCryptfs encrypted files,
   regardless of what eCryptfs winds up doing with the metadata behind the
   scenes.

This patch:

Add extended attribute support to version bit vector, flags to indicate when
xattr or encrypted view modes are enabled, and support for the new mount
options.
Signed-off-by: NMichael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Replace appropriate pairs of "kmem_cache_alloc()" + "memset(0)" with the
corresponding "kmem_cache_zalloc()" call.
Signed-off-by: NRobert P. J. Day <rpjday@mindspring.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Roland McGrath <roland@redhat.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Greg KH <greg@kroah.com>
Acked-by: NJoel Becker <Joel.Becker@oracle.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Jan Kara <jack@ucw.cz>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch removes the old cipher interface and related code.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

SLAB_KERNEL is an alias of GFP_KERNEL.
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

SLAB_USER is an alias of GFP_USER
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The return value of crypto_alloc_blkcipher() should be checked by IS_ERR().

Cc: Mike Halcrow <mhalcrow@us.ibm.com>
Cc: Phillip Hellewell <phillip@hellewell.homeip.net>
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

I missed a pointer dereference in this kmalloc result check.
Signed-off-by: NMichael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Opens on lower dentry objects happen in several places in eCryptfs, and they
all involve the same steps (dget, mntget, dentry_open).  This patch
consolidates the lower open events into a single function call.
Signed-off-by: NMichael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Update cipher block encryption code to the new crypto API.
Signed-off-by: NMichael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Update eCryptfs hash code to the new kernel crypto API.
Signed-off-by: NMichael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Clean up the crypto initialization code; let the crypto API take care of the
key size checks.
Signed-off-by: NMichael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

eCryptfs is a stacked cryptographic filesystem for Linux.  It is derived from
Erez Zadok's Cryptfs, implemented through the FiST framework for generating
stacked filesystems.  eCryptfs extends Cryptfs to provide advanced key
management and policy features.  eCryptfs stores cryptographic metadata in the
header of each file written, so that encrypted files can be copied between
hosts; the file will be decryptable with the proper key, and there is no need
to keep track of any additional information aside from what is already in the
encrypted file itself.

[akpm@osdl.org: updates for ongoing API changes]
[bunk@stusta.de: cleanups]
[akpm@osdl.org: alpha build fix]
[akpm@osdl.org: cleanups]
[tytso@mit.edu: inode-diet updates]
[pbadari@us.ibm.com: generic_file_*_read/write() interface updates]
[rdunlap@xenotime.net: printk format fixes]
[akpm@osdl.org: make slab creation and teardown table-driven]
Signed-off-by: NPhillip Hellewell <phillip@hellewell.homeip.net>
Signed-off-by: NMichael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: NErez Zadok <ezk@cs.sunysb.edu>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NStephan Mueller <smueller@chronox.de>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: NBadari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>