Commit Graph

704 Commits

Author SHA1 Message Date
Hyunchul Lee
e328379a18 ubifs: Fix debug messages for an invalid filename in ubifs_dump_node
if a character is not printable, print '?' instead of that.

Signed-off-by: Hyunchul Lee <cheol.lee@lge.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2017-03-30 09:27:47 +02:00
Hyunchul Lee
b20e2d9999 ubifs: Remove filename from debug messages in ubifs_readdir
if filename is encrypted, filename could have no printable characters.
so remove it.

Signed-off-by: Hyunchul Lee <cheol.lee@lge.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2017-03-30 09:27:28 +02:00
Richard Weinberger
63ed657362 ubifs: Fix memory leak in error path in ubifs_mknod
When fscrypt_setup_filename() fails we have to free dev.

Signed-off-by: Richard Weinberger <richard@nod.at>
2017-03-30 09:27:27 +02:00
David Howells
a528d35e8b statx: Add a system call to make enhanced file info available
Add a system call to make extended file information available, including
file creation and some attribute flags where available through the
underlying filesystem.

The getattr inode operation is altered to take two additional arguments: a
u32 request_mask and an unsigned int flags that indicate the
synchronisation mode.  This change is propagated to the vfs_getattr*()
function.

Functions like vfs_stat() are now inline wrappers around new functions
vfs_statx() and vfs_statx_fd() to reduce stack usage.

========
OVERVIEW
========

The idea was initially proposed as a set of xattrs that could be retrieved
with getxattr(), but the general preference proved to be for a new syscall
with an extended stat structure.

A number of requests were gathered for features to be included.  The
following have been included:

 (1) Make the fields a consistent size on all arches and make them large.

 (2) Spare space, request flags and information flags are provided for
     future expansion.

 (3) Better support for the y2038 problem [Arnd Bergmann] (tv_sec is an
     __s64).

 (4) Creation time: The SMB protocol carries the creation time, which could
     be exported by Samba, which will in turn help CIFS make use of
     FS-Cache as that can be used for coherency data (stx_btime).

     This is also specified in NFSv4 as a recommended attribute and could
     be exported by NFSD [Steve French].

 (5) Lightweight stat: Ask for just those details of interest, and allow a
     netfs (such as NFS) to approximate anything not of interest, possibly
     without going to the server [Trond Myklebust, Ulrich Drepper, Andreas
     Dilger] (AT_STATX_DONT_SYNC).

 (6) Heavyweight stat: Force a netfs to go to the server, even if it thinks
     its cached attributes are up to date [Trond Myklebust]
     (AT_STATX_FORCE_SYNC).

And the following have been left out for future extension:

 (7) Data version number: Could be used by userspace NFS servers [Aneesh
     Kumar].

     Can also be used to modify fill_post_wcc() in NFSD which retrieves
     i_version directly, but has just called vfs_getattr().  It could get
     it from the kstat struct if it used vfs_xgetattr() instead.

     (There's disagreement on the exact semantics of a single field, since
     not all filesystems do this the same way).

 (8) BSD stat compatibility: Including more fields from the BSD stat such
     as creation time (st_btime) and inode generation number (st_gen)
     [Jeremy Allison, Bernd Schubert].

 (9) Inode generation number: Useful for FUSE and userspace NFS servers
     [Bernd Schubert].

     (This was asked for but later deemed unnecessary with the
     open-by-handle capability available and caused disagreement as to
     whether it's a security hole or not).

(10) Extra coherency data may be useful in making backups [Andreas Dilger].

     (No particular data were offered, but things like last backup
     timestamp, the data version number and the DOS archive bit would come
     into this category).

(11) Allow the filesystem to indicate what it can/cannot provide: A
     filesystem can now say it doesn't support a standard stat feature if
     that isn't available, so if, for instance, inode numbers or UIDs don't
     exist or are fabricated locally...

     (This requires a separate system call - I have an fsinfo() call idea
     for this).

(12) Store a 16-byte volume ID in the superblock that can be returned in
     struct xstat [Steve French].

     (Deferred to fsinfo).

(13) Include granularity fields in the time data to indicate the
     granularity of each of the times (NFSv4 time_delta) [Steve French].

     (Deferred to fsinfo).

(14) FS_IOC_GETFLAGS value.  These could be translated to BSD's st_flags.
     Note that the Linux IOC flags are a mess and filesystems such as Ext4
     define flags that aren't in linux/fs.h, so translation in the kernel
     may be a necessity (or, possibly, we provide the filesystem type too).

     (Some attributes are made available in stx_attributes, but the general
     feeling was that the IOC flags were to ext[234]-specific and shouldn't
     be exposed through statx this way).

(15) Mask of features available on file (eg: ACLs, seclabel) [Brad Boyer,
     Michael Kerrisk].

     (Deferred, probably to fsinfo.  Finding out if there's an ACL or
     seclabal might require extra filesystem operations).

(16) Femtosecond-resolution timestamps [Dave Chinner].

     (A __reserved field has been left in the statx_timestamp struct for
     this - if there proves to be a need).

(17) A set multiple attributes syscall to go with this.

===============
NEW SYSTEM CALL
===============

The new system call is:

	int ret = statx(int dfd,
			const char *filename,
			unsigned int flags,
			unsigned int mask,
			struct statx *buffer);

The dfd, filename and flags parameters indicate the file to query, in a
similar way to fstatat().  There is no equivalent of lstat() as that can be
emulated with statx() by passing AT_SYMLINK_NOFOLLOW in flags.  There is
also no equivalent of fstat() as that can be emulated by passing a NULL
filename to statx() with the fd of interest in dfd.

Whether or not statx() synchronises the attributes with the backing store
can be controlled by OR'ing a value into the flags argument (this typically
only affects network filesystems):

 (1) AT_STATX_SYNC_AS_STAT tells statx() to behave as stat() does in this
     respect.

 (2) AT_STATX_FORCE_SYNC will require a network filesystem to synchronise
     its attributes with the server - which might require data writeback to
     occur to get the timestamps correct.

 (3) AT_STATX_DONT_SYNC will suppress synchronisation with the server in a
     network filesystem.  The resulting values should be considered
     approximate.

mask is a bitmask indicating the fields in struct statx that are of
interest to the caller.  The user should set this to STATX_BASIC_STATS to
get the basic set returned by stat().  It should be noted that asking for
more information may entail extra I/O operations.

buffer points to the destination for the data.  This must be 256 bytes in
size.

======================
MAIN ATTRIBUTES RECORD
======================

The following structures are defined in which to return the main attribute
set:

	struct statx_timestamp {
		__s64	tv_sec;
		__s32	tv_nsec;
		__s32	__reserved;
	};

	struct statx {
		__u32	stx_mask;
		__u32	stx_blksize;
		__u64	stx_attributes;
		__u32	stx_nlink;
		__u32	stx_uid;
		__u32	stx_gid;
		__u16	stx_mode;
		__u16	__spare0[1];
		__u64	stx_ino;
		__u64	stx_size;
		__u64	stx_blocks;
		__u64	__spare1[1];
		struct statx_timestamp	stx_atime;
		struct statx_timestamp	stx_btime;
		struct statx_timestamp	stx_ctime;
		struct statx_timestamp	stx_mtime;
		__u32	stx_rdev_major;
		__u32	stx_rdev_minor;
		__u32	stx_dev_major;
		__u32	stx_dev_minor;
		__u64	__spare2[14];
	};

The defined bits in request_mask and stx_mask are:

	STATX_TYPE		Want/got stx_mode & S_IFMT
	STATX_MODE		Want/got stx_mode & ~S_IFMT
	STATX_NLINK		Want/got stx_nlink
	STATX_UID		Want/got stx_uid
	STATX_GID		Want/got stx_gid
	STATX_ATIME		Want/got stx_atime{,_ns}
	STATX_MTIME		Want/got stx_mtime{,_ns}
	STATX_CTIME		Want/got stx_ctime{,_ns}
	STATX_INO		Want/got stx_ino
	STATX_SIZE		Want/got stx_size
	STATX_BLOCKS		Want/got stx_blocks
	STATX_BASIC_STATS	[The stuff in the normal stat struct]
	STATX_BTIME		Want/got stx_btime{,_ns}
	STATX_ALL		[All currently available stuff]

stx_btime is the file creation time, stx_mask is a bitmask indicating the
data provided and __spares*[] are where as-yet undefined fields can be
placed.

Time fields are structures with separate seconds and nanoseconds fields
plus a reserved field in case we want to add even finer resolution.  Note
that times will be negative if before 1970; in such a case, the nanosecond
fields will also be negative if not zero.

The bits defined in the stx_attributes field convey information about a
file, how it is accessed, where it is and what it does.  The following
attributes map to FS_*_FL flags and are the same numerical value:

	STATX_ATTR_COMPRESSED		File is compressed by the fs
	STATX_ATTR_IMMUTABLE		File is marked immutable
	STATX_ATTR_APPEND		File is append-only
	STATX_ATTR_NODUMP		File is not to be dumped
	STATX_ATTR_ENCRYPTED		File requires key to decrypt in fs

Within the kernel, the supported flags are listed by:

	KSTAT_ATTR_FS_IOC_FLAGS

[Are any other IOC flags of sufficient general interest to be exposed
through this interface?]

New flags include:

	STATX_ATTR_AUTOMOUNT		Object is an automount trigger

These are for the use of GUI tools that might want to mark files specially,
depending on what they are.

Fields in struct statx come in a number of classes:

 (0) stx_dev_*, stx_blksize.

     These are local system information and are always available.

 (1) stx_mode, stx_nlinks, stx_uid, stx_gid, stx_[amc]time, stx_ino,
     stx_size, stx_blocks.

     These will be returned whether the caller asks for them or not.  The
     corresponding bits in stx_mask will be set to indicate whether they
     actually have valid values.

     If the caller didn't ask for them, then they may be approximated.  For
     example, NFS won't waste any time updating them from the server,
     unless as a byproduct of updating something requested.

     If the values don't actually exist for the underlying object (such as
     UID or GID on a DOS file), then the bit won't be set in the stx_mask,
     even if the caller asked for the value.  In such a case, the returned
     value will be a fabrication.

     Note that there are instances where the type might not be valid, for
     instance Windows reparse points.

 (2) stx_rdev_*.

     This will be set only if stx_mode indicates we're looking at a
     blockdev or a chardev, otherwise will be 0.

 (3) stx_btime.

     Similar to (1), except this will be set to 0 if it doesn't exist.

=======
TESTING
=======

The following test program can be used to test the statx system call:

	samples/statx/test-statx.c

Just compile and run, passing it paths to the files you want to examine.
The file is built automatically if CONFIG_SAMPLES is enabled.

Here's some example output.  Firstly, an NFS directory that crosses to
another FSID.  Note that the AUTOMOUNT attribute is set because transiting
this directory will cause d_automount to be invoked by the VFS.

	[root@andromeda ~]# /tmp/test-statx -A /warthog/data
	statx(/warthog/data) = 0
	results=7ff
	  Size: 4096            Blocks: 8          IO Block: 1048576  directory
	Device: 00:26           Inode: 1703937     Links: 125
	Access: (3777/drwxrwxrwx)  Uid:     0   Gid:  4041
	Access: 2016-11-24 09:02:12.219699527+0000
	Modify: 2016-11-17 10:44:36.225653653+0000
	Change: 2016-11-17 10:44:36.225653653+0000
	Attributes: 0000000000001000 (-------- -------- -------- -------- -------- -------- ---m---- --------)

Secondly, the result of automounting on that directory.

	[root@andromeda ~]# /tmp/test-statx /warthog/data
	statx(/warthog/data) = 0
	results=7ff
	  Size: 4096            Blocks: 8          IO Block: 1048576  directory
	Device: 00:27           Inode: 2           Links: 125
	Access: (3777/drwxrwxrwx)  Uid:     0   Gid:  4041
	Access: 2016-11-24 09:02:12.219699527+0000
	Modify: 2016-11-17 10:44:36.225653653+0000
	Change: 2016-11-17 10:44:36.225653653+0000

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-03-02 20:51:15 -05:00
Dave Jiang
11bac80004 mm, fs: reduce fault, page_mkwrite, and pfn_mkwrite to take only vmf
->fault(), ->page_mkwrite(), and ->pfn_mkwrite() calls do not need to
take a vma and vmf parameter when the vma already resides in vmf.

Remove the vma parameter to simplify things.

[arnd@arndb.de: fix ARM build]
  Link: http://lkml.kernel.org/r/20170125223558.1451224-1-arnd@arndb.de
Link: http://lkml.kernel.org/r/148521301778.19116.10840599906674778980.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jan Kara <jack@suse.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-24 17:46:54 -08:00
Linus Torvalds
6c24337f22 Various cleanups for the file system encryption feature.
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Merge tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/fscrypt

Pull fscrypt updates from Ted Ts'o:
 "Various cleanups for the file system encryption feature"

* tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/fscrypt:
  fscrypt: constify struct fscrypt_operations
  fscrypt: properly declare on-stack completion
  fscrypt: split supp and notsupp declarations into their own headers
  fscrypt: remove redundant assignment of res
  fscrypt: make fscrypt_operations.key_prefix a string
  fscrypt: remove unused 'mode' member of fscrypt_ctx
  ext4: don't allow encrypted operations without keys
  fscrypt: make test_dummy_encryption require a keyring key
  fscrypt: factor out bio specific functions
  fscrypt: pass up error codes from ->get_context()
  fscrypt: remove user-triggerable warning messages
  fscrypt: use EEXIST when file already uses different policy
  fscrypt: use ENOTDIR when setting encryption policy on nondirectory
  fscrypt: use ENOKEY when file cannot be created w/o key
2017-02-20 18:22:31 -08:00
Eric Biggers
6f69f0ed61 fscrypt: constify struct fscrypt_operations
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Richard Weinberger <richard@nod.at>
2017-02-08 10:59:57 -05:00
Eric Biggers
46f47e4800 fscrypt: split supp and notsupp declarations into their own headers
Previously, each filesystem configured without encryption support would
define all the public fscrypt functions to their notsupp_* stubs.  This
list of #defines had to be updated in every filesystem whenever a change
was made to the public fscrypt functions.  To make things more
maintainable now that we have three filesystems using fscrypt, split the
old header fscrypto.h into several new headers.  fscrypt_supp.h contains
the real declarations and is included by filesystems when configured
with encryption support, whereas fscrypt_notsupp.h contains the inline
stubs and is included by filesystems when configured without encryption
support.  fscrypt_common.h contains common declarations needed by both.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-02-06 23:26:43 -05:00
Richard Weinberger
1cb51a15b5 ubifs: Fix journal replay wrt. xattr nodes
When replaying the journal it can happen that a journal entry points to
a garbage collected node.
This is the case when a power-cut occurred between a garbage collect run
and a commit. In such a case nodes have to be read using the failable
read functions to detect whether the found node matches what we expect.

One corner case was forgotten, when the journal contains an entry to
remove an inode all xattrs have to be removed too. UBIFS models xattr
like directory entries, so the TNC code iterates over
all xattrs of the inode and removes them too. This code re-uses the
functions for walking directories and calls ubifs_tnc_next_ent().
ubifs_tnc_next_ent() expects to be used only after the journal and
aborts when a node does not match the expected result. This behavior can
render an UBIFS volume unmountable after a power-cut when xattrs are
used.

Fix this issue by using failable read functions in ubifs_tnc_next_ent()
too when replaying the journal.
Cc: stable@vger.kernel.org
Fixes: 1e51764a3c ("UBIFS: add new flash file system")
Reported-by: Rock Lee <rockdotlee@gmail.com>
Reviewed-by: David Gstir <david@sigma-star.at>
Signed-off-by: Richard Weinberger <richard@nod.at>
2017-01-17 14:35:58 +01:00
Eric Biggers
3d4b2fcbc9 ubifs: remove redundant checks for encryption key
In several places, ubifs checked for an encryption key before creating a
file in an encrypted directory.  This was redundant with
fscrypt_setup_filename() or ubifs_new_inode(), and in the case of
ubifs_link() it broke linking to special files.  So remove the extra
checks.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2017-01-17 14:34:21 +01:00
Eric Biggers
a75467d910 ubifs: allow encryption ioctls in compat mode
The ubifs encryption ioctls did not work when called by a 32-bit program
on a 64-bit kernel.  Since 'struct fscrypt_policy' is not affected by
the word size, ubifs just needs to allow these ioctls through, like what
ext4 and f2fs do.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2017-01-17 14:33:41 +01:00
Arnd Bergmann
404e0b6331 ubifs: add CONFIG_BLOCK dependency for encryption
This came up during the v4.10 merge window:

warning: (UBIFS_FS_ENCRYPTION) selects FS_ENCRYPTION which has unmet direct dependencies (BLOCK)
fs/crypto/crypto.c: In function 'fscrypt_zeroout_range':
fs/crypto/crypto.c:355:9: error: implicit declaration of function 'bio_alloc';did you mean 'd_alloc'? [-Werror=implicit-function-declaration]
   bio = bio_alloc(GFP_NOWAIT, 1);

The easiest way out is to limit UBIFS_FS_ENCRYPTION to configurations
that also enable BLOCK.

Fixes: d475a50745 ("ubifs: Add skeleton for fscrypto")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Richard Weinberger <richard@nod.at>
2017-01-17 14:32:47 +01:00
Peter Rosin
507502adf0 ubifs: fix unencrypted journal write
Without this, I get the following on reboot:

UBIFS error (ubi1:0 pid 703): ubifs_load_znode: bad target node (type 1) length (8240)
UBIFS error (ubi1:0 pid 703): ubifs_load_znode: have to be in range of 48-4144
UBIFS error (ubi1:0 pid 703): ubifs_load_znode: bad indexing node at LEB 13:11080, error 5
 magic          0x6101831
 crc            0xb1cb246f
 node_type      9 (indexing node)
 group_type     0 (no node group)
 sqnum          546
 len            128
 child_cnt      5
 level          0
 Branches:
 0: LEB 14:72088 len 161 key (133, inode)
 1: LEB 14:81120 len 160 key (134, inode)
 2: LEB 20:26624 len 8240 key (134, data, 0)
 3: LEB 14:81280 len 160 key (135, inode)
 4: LEB 20:34864 len 8240 key (135, data, 0)
UBIFS warning (ubi1:0 pid 703): ubifs_ro_mode.part.0: switched to read-only mode, error -22
CPU: 0 PID: 703 Comm: mount Not tainted 4.9.0-next-20161213+ #1197
Hardware name: Atmel SAMA5
[<c010d2ac>] (unwind_backtrace) from [<c010b250>] (show_stack+0x10/0x14)
[<c010b250>] (show_stack) from [<c024df94>] (ubifs_jnl_update+0x2e8/0x614)
[<c024df94>] (ubifs_jnl_update) from [<c0254bf8>] (ubifs_mkdir+0x160/0x204)
[<c0254bf8>] (ubifs_mkdir) from [<c01a6030>] (vfs_mkdir+0xb0/0x104)
[<c01a6030>] (vfs_mkdir) from [<c0286070>] (ovl_create_real+0x118/0x248)
[<c0286070>] (ovl_create_real) from [<c0283ed4>] (ovl_fill_super+0x994/0xaf4)
[<c0283ed4>] (ovl_fill_super) from [<c019c394>] (mount_nodev+0x44/0x9c)
[<c019c394>] (mount_nodev) from [<c019c4ac>] (mount_fs+0x14/0xa4)
[<c019c4ac>] (mount_fs) from [<c01b5338>] (vfs_kern_mount+0x4c/0xd4)
[<c01b5338>] (vfs_kern_mount) from [<c01b6b80>] (do_mount+0x154/0xac8)
[<c01b6b80>] (do_mount) from [<c01b782c>] (SyS_mount+0x74/0x9c)
[<c01b782c>] (SyS_mount) from [<c0107f80>] (ret_fast_syscall+0x0/0x3c)
UBIFS error (ubi1:0 pid 703): ubifs_mkdir: cannot create directory, error -22
overlayfs: failed to create directory /mnt/ovl/work/work (errno: 22); mounting read-only

Fixes: 7799953b34 ("ubifs: Implement encrypt/decrypt for all IO")
Signed-off-by: Peter Rosin <peda@axentia.se>
Tested-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2017-01-17 14:05:23 +01:00
Colin Ian King
e8f19746e4 ubifs: ensure zero err is returned on successful return
err is no longer being set on a successful return path, causing
a garbage value being returned. Fix this by setting err to zero
for the successful return path.

Found with static analysis by CoverityScan, CID 1389473

Fixes: 7799953b34 ("ubifs: Implement encrypt/decrypt for all IO")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2017-01-17 13:57:32 +01:00
Eric Biggers
a5d431eff2 fscrypt: make fscrypt_operations.key_prefix a string
There was an unnecessary amount of complexity around requesting the
filesystem-specific key prefix.  It was unclear why; perhaps it was
envisioned that different instances of the same filesystem type could
use different key prefixes, or that key prefixes could be binary.
However, neither of those things were implemented or really make sense
at all.  So simplify the code by making key_prefix a const char *.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-01-08 01:03:41 -05:00
Linus Torvalds
231753ef78 Merge uncontroversial parts of branch 'readlink' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs
Pull partial readlink cleanups from Miklos Szeredi.

This is the uncontroversial part of the readlink cleanup patch-set that
simplifies the default readlink handling.

Miklos and Al are still discussing the rest of the series.

* git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  vfs: make generic_readlink() static
  vfs: remove ".readlink = generic_readlink" assignments
  vfs: default to generic_readlink()
  vfs: replace calling i_op->readlink with vfs_readlink()
  proc/self: use generic_readlink
  ecryptfs: use vfs_get_link()
  bad_inode: add missing i_op initializers
2016-12-17 19:16:12 -08:00
Richard Weinberger
ba75d570b6 ubifs: Initialize fstr_real_len
While fstr_real_len is only being used under if (encrypted),
gcc-6 still warns.

Fixes this false positive:
fs/ubifs/dir.c: In function 'ubifs_readdir':
fs/ubifs/dir.c:629:13: warning: 'fstr_real_len' may be used
uninitialized in this function [-Wmaybe-uninitialized]
    fstr.len = fstr_real_len

Initialize fstr_real_len to make gcc happy.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Richard Weinberger <richard@nod.at>
2016-12-14 17:39:21 +01:00
Richard Weinberger
ec9160dacd ubifs: Use fscrypt ioctl() helpers
Commit db717d8e26 ("fscrypto: move ioctl processing more fully into
common code") moved ioctl() related functions into fscrypt and offers
us now a set of helper functions.

Signed-off-by: Richard Weinberger <richard@nod.at>
Reviewed-by: David Gstir <david@sigma-star.at>
2016-12-13 19:54:52 +01:00
Richard Weinberger
3858866866 ubifs: Use FS_CFLG_OWN_PAGES
Commit bd7b829038 ("fscrypt: Cleanup page locking requirements for
fscrypt_{decrypt,encrypt}_page()") renamed the flag.

Signed-off-by: Richard Weinberger <richard@nod.at>
2016-12-13 16:18:16 +01:00
Richard Weinberger
fc4b891bbe ubifs: Raise write version to 5
Starting with version 5 the following properties change:
 - UBIFS_FLG_DOUBLE_HASH is mandatory
 - UBIFS_FLG_ENCRYPTION is optional but depdens on UBIFS_FLG_DOUBLE_HASH
 - Filesystems with unknown super block flags will be rejected, this
   allows us in future to add new features without raising the UBIFS
   write version.

Signed-off-by: Richard Weinberger <richard@nod.at>
2016-12-12 23:07:38 +01:00
Richard Weinberger
e021986ee4 ubifs: Implement UBIFS_FLG_ENCRYPTION
This feature flag indicates that the filesystem contains encrypted
files.

Signed-off-by: Richard Weinberger <richard@nod.at>
2016-12-12 23:07:38 +01:00
Richard Weinberger
d63d61c169 ubifs: Implement UBIFS_FLG_DOUBLE_HASH
This feature flag indicates that all directory entry nodes have a 32bit
cookie set and therefore UBIFS is allowed to perform lookups by hash.

Signed-off-by: Richard Weinberger <richard@nod.at>
2016-12-12 23:07:38 +01:00
Richard Weinberger
cc41a53652 ubifs: Use a random number for cookies
Signed-off-by: Richard Weinberger <richard@nod.at>
2016-12-12 23:07:38 +01:00
Richard Weinberger
528e3d178f ubifs: Add full hash lookup support
UBIFS stores a 32bit hash of every file, for traditional lookups by name
this scheme is fine since UBIFS can first try to find the file by the
hash of the filename and upon collisions it can walk through all entries
with the same hash and do a string compare.
When filesnames are encrypted fscrypto will ask the filesystem for a
unique cookie, based on this cookie the filesystem has to be able to
locate the target file again. With 32bit hashes this is impossible
because the chance for collisions is very high. Do deal with that we
store a 32bit cookie directly in the UBIFS directory entry node such
that we get a 64bit cookie (32bit from filename hash and the dent
cookie). For a lookup by hash UBIFS finds the entry by the first 32bit
and then compares the dent cookie. If it does not match, it has to do a
linear search of the whole directory and compares all dent cookies until
the correct entry is found.

Signed-off-by: Richard Weinberger <richard@nod.at>
2016-12-12 23:07:38 +01:00
Richard Weinberger
b91dc9816e ubifs: Rename tnc_read_node_nm
tnc_read_hashed_node() is a better name since we read a node
by a given hash, not a name.

Signed-off-by: Richard Weinberger <richard@nod.at>
2016-12-12 23:07:38 +01:00
Richard Weinberger
ca7f85be8d ubifs: Add support for encrypted symlinks
Signed-off-by: Richard Weinberger <richard@nod.at>
2016-12-12 23:07:38 +01:00
Richard Weinberger
f4f61d2cc6 ubifs: Implement encrypted filenames
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: David Gstir <david@sigma-star.at>
Signed-off-by: Richard Weinberger <richard@nod.at>
2016-12-12 23:07:38 +01:00
Richard Weinberger
b9bc8c7bdb ubifs: Make r5 hash binary string aware
As of now all filenames known by UBIFS are strings with a NUL
terminator. With encrypted filenames a filename can be any binary
string and the r5 function cannot search for the NUL terminator.
UBIFS always knows how long a filename is, therefore we can change
the hash function to iterate over the filename length to work
correctly with binary strings.

Signed-off-by: Richard Weinberger <richard@nod.at>
2016-12-12 23:07:38 +01:00
Richard Weinberger
304790c038 ubifs: Relax checks in ubifs_validate_entry()
With encrypted filenames we store raw binary data, doing
string tests is no longer possible.

Signed-off-by: Richard Weinberger <richard@nod.at>
2016-12-12 23:07:38 +01:00
Richard Weinberger
7799953b34 ubifs: Implement encrypt/decrypt for all IO
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: David Gstir <david@sigma-star.at>
Signed-off-by: Richard Weinberger <richard@nod.at>
2016-12-12 23:07:38 +01:00
Richard Weinberger
1ee77870c9 ubifs: Constify struct inode pointer in ubifs_crypt_is_encrypted()
...and provide a non const variant for fscrypto

Signed-off-by: Richard Weinberger <richard@nod.at>
2016-12-12 23:07:38 +01:00
Richard Weinberger
f1f52d6b02 ubifs: Introduce new data node field, compr_size
When data of a data node is compressed and encrypted
we need to store the size of the compressed data because
before encryption we may have to add padding bytes.

For the new field we consume the last two padding bytes
in struct ubifs_data_node. Two bytes are fine because
the data length is at most 4096.

Signed-off-by: Richard Weinberger <richard@nod.at>
2016-12-12 23:07:38 +01:00
Richard Weinberger
959c2de2b3 ubifs: Enforce crypto policy in mmap
We need this extra check in mmap because a process could
gain an already opened fd.

Signed-off-by: Richard Weinberger <richard@nod.at>
2016-12-12 23:07:38 +01:00
Richard Weinberger
700eada82a ubifs: Massage assert in ubifs_xattr_set() wrt. fscrypto
When we're creating a new inode in UBIFS the inode is not
yet exposed and fscrypto calls ubifs_xattr_set() without
holding the inode mutex. This is okay but ubifs_xattr_set()
has to know about this.

Signed-off-by: Richard Weinberger <richard@nod.at>
2016-12-12 23:07:38 +01:00
Richard Weinberger
9270b2f4cd ubifs: Preload crypto context in ->lookup()
...and mark the dentry as encrypted.

Signed-off-by: Richard Weinberger <richard@nod.at>
2016-12-12 23:07:38 +01:00
Richard Weinberger
ac7e47a9ed ubifs: Enforce crypto policy in ->link and ->rename
When a file is moved or linked into another directory
its current crypto policy has to be compatible with the
target policy.

Signed-off-by: Richard Weinberger <richard@nod.at>
2016-12-12 23:07:38 +01:00
Richard Weinberger
a79bff21c1 ubifs: Implement file open operation
We need ->open() for files to load the crypto key.
If the no key is present and the file is encrypted,
refuse to open.

Signed-off-by: Richard Weinberger <richard@nod.at>
2016-12-12 23:07:38 +01:00
Richard Weinberger
ba40e6a3c4 ubifs: Implement directory open operation
We need the ->open() hook to load the crypto context
which is needed for all crypto operations within that
directory.

Signed-off-by: Richard Weinberger <richard@nod.at>
2016-12-12 23:07:38 +01:00
Richard Weinberger
43b113fea2 ubifs: Massage ubifs_listxattr() for encryption context
We have to make sure that we don't expose our internal
crypto context to userspace.

Signed-off-by: Richard Weinberger <richard@nod.at>
2016-12-12 23:07:38 +01:00
Richard Weinberger
d475a50745 ubifs: Add skeleton for fscrypto
This is the first building block to provide file level
encryption on UBIFS.

Signed-off-by: Richard Weinberger <richard@nod.at>
2016-12-12 23:07:38 +01:00
Richard Weinberger
6a5e98ab7d ubifs: Define UBIFS crypto context xattr
Like ext4 UBIFS will store the crypto context in a xattr
attribute.

Signed-off-by: Richard Weinberger <richard@nod.at>
2016-12-12 23:07:38 +01:00
Richard Weinberger
ade46c3a60 ubifs: Export xattr get and set functions
For fscrypto we need this function outside of xattr.c.

Signed-off-by: Richard Weinberger <richard@nod.at>
2016-12-12 23:07:38 +01:00
Richard Weinberger
f6337d8426 ubifs: Export ubifs_check_dir_empty()
fscrypto will need this function too. Also get struct ubifs_info
from the provided inode. Not all callers will have a reference to
struct ubifs_info.

Signed-off-by: Richard Weinberger <richard@nod.at>
2016-12-12 23:07:38 +01:00
Christophe Jaillet
d40a796217 ubifs: Remove some dead code
'ubifs_fast_find_freeable()' can not return an error pointer, so this test
can be removed.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Richard Weinberger <richard@nod.at>
2016-12-12 23:06:28 +01:00
Rafał Miłecki
1b7fc2c006 ubifs: Use dirty_writeback_interval value for wbuf timer
Right now wbuf timer has hardcoded timeouts and there is no place for
manual adjustments. Some projects / cases many need that though. Few
file systems allow doing that by respecting dirty_writeback_interval
that can be set using sysctl (dirty_writeback_centisecs).

Lowering dirty_writeback_interval could be some way of dealing with user
space apps lacking proper fsyncs. This is definitely *not* a perfect
solution but we don't have ideal (user space) world. There were already
advanced discussions on this matter, mostly when ext4 was introduced and
it wasn't behaving as ext3. Anyway, the final decision was to add some
hacks to the ext4, as trying to fix whole user space or adding new API
was pointless.

We can't (and shouldn't?) just follow ext4. We can't e.g. sync on close
as this would cause too many commits and flash wearing. On the other
hand we still should allow some trade-off between -o sync and default
wbuf timeout. Respecting dirty_writeback_interval should allow some sane
cutomizations if used warily.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2016-12-12 23:06:24 +01:00
Rafał Miłecki
854826c9d5 ubifs: Drop softlimit and delta fields from struct ubifs_wbuf
Values of these fields are set during init and never modified. They are
used (read) in a single function only. There isn't really any reason to
keep them in a struct. It only makes struct just a bit bigger without
any visible gain.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2016-12-12 23:06:11 +01:00
Miklos Szeredi
dfeef68862 vfs: remove ".readlink = generic_readlink" assignments
If .readlink == NULL implies generic_readlink().

Generated by:

to_del="\.readlink.*=.*generic_readlink"
for i in `git grep -l $to_del`; do sed -i "/$to_del"/d $i; done

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-12-09 16:45:04 +01:00
Richard Weinberger
a00052a296 ubifs: Fix regression in ubifs_readdir()
Commit c83ed4c9db ("ubifs: Abort readdir upon error") broke
overlayfs support because the fix exposed an internal error
code to VFS.

Reported-by: Peter Rosin <peda@axentia.se>
Tested-by: Peter Rosin <peda@axentia.se>
Reported-by: Ralph Sennhauser <ralph.sennhauser@gmail.com>
Tested-by: Ralph Sennhauser <ralph.sennhauser@gmail.com>
Fixes: c83ed4c9db ("ubifs: Abort readdir upon error")
Cc: stable@vger.kernel.org
Signed-off-by: Richard Weinberger <richard@nod.at>
2016-10-28 14:48:31 +02:00
Richard Weinberger
c83ed4c9db ubifs: Abort readdir upon error
If UBIFS is facing an error while walking a directory, it reports this
error and ubifs_readdir() returns the error code. But the VFS readdir
logic does not make the getdents system call fail in all cases. When the
readdir cursor indicates that more entries are present, the system call
will just return and the libc wrapper will try again since it also
knows that more entries are present.
This causes the libc wrapper to busy loop for ever when a directory is
corrupted on UBIFS.
A common approach do deal with corrupted directory entries is
skipping them by setting the cursor to the next entry. On UBIFS this
approach is not possible since we cannot compute the next directory
entry cursor position without reading the current entry. So all we can
do is setting the cursor to the "no more entries" position and make
getdents exit.

Cc: stable@vger.kernel.org
Signed-off-by: Richard Weinberger <richard@nod.at>
2016-10-20 00:06:11 +02:00
Richard Weinberger
843741c577 ubifs: Fix xattr_names length in exit paths
When the operation fails we also have to undo the changes
we made to ->xattr_names. Otherwise listxattr() will report
wrong lengths.

Cc: stable@vger.kernel.org
Signed-off-by: Richard Weinberger <richard@nod.at>
2016-10-20 00:05:54 +02:00