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: NRichard Weinberger <richard@nod.at>

tnc_read_hashed_node() is a better name since we read a node
by a given hash, not a name.
Signed-off-by: NRichard Weinberger <richard@nod.at>

Signed-off-by: NRichard Weinberger <richard@nod.at>

Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NDavid Gstir <david@sigma-star.at>
Signed-off-by: NRichard Weinberger <richard@nod.at>

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: NRichard Weinberger <richard@nod.at>

With encrypted filenames we store raw binary data, doing
string tests is no longer possible.
Signed-off-by: NRichard Weinberger <richard@nod.at>

Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NDavid Gstir <david@sigma-star.at>
Signed-off-by: NRichard Weinberger <richard@nod.at>

...and provide a non const variant for fscrypto
Signed-off-by: NRichard Weinberger <richard@nod.at>

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: NRichard Weinberger <richard@nod.at>

We need this extra check in mmap because a process could
gain an already opened fd.
Signed-off-by: NRichard Weinberger <richard@nod.at>

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: NRichard Weinberger <richard@nod.at>

...and mark the dentry as encrypted.
Signed-off-by: NRichard Weinberger <richard@nod.at>

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: NRichard Weinberger <richard@nod.at>

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: NRichard Weinberger <richard@nod.at>

We need the ->open() hook to load the crypto context
which is needed for all crypto operations within that
directory.
Signed-off-by: NRichard Weinberger <richard@nod.at>

We have to make sure that we don't expose our internal
crypto context to userspace.
Signed-off-by: NRichard Weinberger <richard@nod.at>

This is the first building block to provide file level
encryption on UBIFS.
Signed-off-by: NRichard Weinberger <richard@nod.at>

Like ext4 UBIFS will store the crypto context in a xattr
attribute.
Signed-off-by: NRichard Weinberger <richard@nod.at>

For fscrypto we need this function outside of xattr.c.
Signed-off-by: NRichard Weinberger <richard@nod.at>

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: NRichard Weinberger <richard@nod.at>

'ubifs_fast_find_freeable()' can not return an error pointer, so this test
can be removed.
Signed-off-by: NChristophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: NRichard Weinberger <richard@nod.at>

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: NRafał Miłecki <rafal@milecki.pl>
Reviewed-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

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: NRafał Miłecki <rafal@milecki.pl>
Reviewed-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

Commit c83ed4c9 ("ubifs: Abort readdir upon error") broke
overlayfs support because the fix exposed an internal error
code to VFS.
Reported-by: NPeter Rosin <peda@axentia.se>
Tested-by: NPeter Rosin <peda@axentia.se>
Reported-by: NRalph Sennhauser <ralph.sennhauser@gmail.com>
Tested-by: NRalph Sennhauser <ralph.sennhauser@gmail.com>
Fixes: c83ed4c9 ("ubifs: Abort readdir upon error")
Cc: stable@vger.kernel.org
Signed-off-by: NRichard Weinberger <richard@nod.at>

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: NRichard Weinberger <richard@nod.at>

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: NRichard Weinberger <richard@nod.at>

Since ->rename2 is gone, rename ubifs_rename2() to ubifs_rename().
Suggested-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NRichard Weinberger <richard@nod.at>

These inode operations are no longer used; remove them.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Fix various inconsistencies in the documentation associated with various
functions.

In the case of fs/ubifs/lprops.c, the second parameter of
ubifs_get_lp_stats was renamed from st to lst in commit 84abf972
("UBIFS: add re-mount debugging checks")

In the case of fs/ubifs/lpt_commit.c, the excess variables have never
existed in the associated functions since the code was introduced into the
kernel.

The others appear to be straightforward typos.

Issues detected using Coccinelle (http://coccinelle.lip6.fr/)
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: NRichard Weinberger <richard@nod.at>

When an extended attribute is changed, xattr_len of host inode is
recalculated. ui->data_len is updated before computation and result
is wrong. This patch adds a temporary variable to fix computation.

To reproduce the issue:

~# > a.txt
~# attr -s an-attr -V a-value a.txt
~# attr -s an-attr -V a-bit-bigger-value a.txt

Now host inode xattr_len is wrong. Forcing dbg_check_filesystem()
generates the following error:

[  130.620140] UBIFS (ubi0:2): background thread "ubifs_bgt0_2" started, PID 565
[  131.470790] UBIFS error (ubi0:2 pid 564): check_inodes: inode 646 has xattr size 240, but calculated size is 256
[  131.481697] UBIFS (ubi0:2): dump of the inode 646 sitting in LEB 29:114688
[  131.488953]  magic          0x6101831
[  131.492876]  crc            0x9fce9091
[  131.496836]  node_type      0 (inode node)
[  131.501193]  group_type     1 (in node group)
[  131.505788]  sqnum          9278
[  131.509191]  len            160
[  131.512549]  key            (646, inode)
[  131.516688]  creat_sqnum    9270
[  131.520133]  size           0
[  131.523264]  nlink          1
[  131.526398]  atime          1053025857.0
[  131.530574]  mtime          1053025857.0
[  131.534714]  ctime          1053025906.0
[  131.538849]  uid            0
[  131.542009]  gid            0
[  131.545140]  mode           33188
[  131.548636]  flags          0x1
[  131.551977]  xattr_cnt      1
[  131.555108]  xattr_size     240
[  131.558420]  xattr_names    12
[  131.561670]  compr_type     0x1
[  131.564983]  data len       0
[  131.568125] UBIFS error (ubi0:2 pid 564): dbg_check_filesystem: file-system check failed with error -22
[  131.578074] CPU: 0 PID: 564 Comm: mount Not tainted 4.4.12-g3639bea54a #24
[  131.585352] Hardware name: Generic AM33XX (Flattened Device Tree)
[  131.591918] [<c00151c0>] (unwind_backtrace) from [<c0012acc>] (show_stack+0x10/0x14)
[  131.600177] [<c0012acc>] (show_stack) from [<c01c950c>] (dbg_check_filesystem+0x464/0x4d0)
[  131.608934] [<c01c950c>] (dbg_check_filesystem) from [<c019f36c>] (ubifs_mount+0x14f8/0x2130)
[  131.617991] [<c019f36c>] (ubifs_mount) from [<c00d7088>] (mount_fs+0x14/0x98)
[  131.625572] [<c00d7088>] (mount_fs) from [<c00ed674>] (vfs_kern_mount+0x4c/0xd4)
[  131.633435] [<c00ed674>] (vfs_kern_mount) from [<c00efb5c>] (do_mount+0x988/0xb50)
[  131.641471] [<c00efb5c>] (do_mount) from [<c00f004c>] (SyS_mount+0x74/0xa0)
[  131.648837] [<c00f004c>] (SyS_mount) from [<c000fe20>] (ret_fast_syscall+0x0/0x3c)
[  131.665315] UBIFS (ubi0:2): background thread "ubifs_bgt0_2" stops
Signed-off-by: NPascal Eberhard <pascal.eberhard@gmail.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

...to make the code more consistent since we use
move already in other places.
Signed-off-by: NRichard Weinberger <richard@nod.at>

Adds RENAME_EXCHANGE to UBIFS, the operation itself
is completely disjunct from a regular rename() that's
why we dispatch very early in ubifs_reaname().

RENAME_EXCHANGE used by the renameat2() system call
allows the caller to exchange two paths atomically.
Both paths have to exist and have to be on the same
filesystem.
Signed-off-by: NRichard Weinberger <richard@nod.at>

Adds RENAME_WHITEOUT support to UBIFS, we implement
it in the same way as ext4 and xfs do.
For an overview of other ways to implement it please
refere to commit 7dcf5c3e ("xfs: add RENAME_WHITEOUT support").
Signed-off-by: NRichard Weinberger <richard@nod.at>

This patchs adds O_TMPFILE support to UBIFS.
A temp file is a reference to an unlinked inode, a user
holding the reference can use it. As soon it is being closed
all data vanishes.
Signed-off-by: NRichard Weinberger <richard@nod.at>

Generated patch:

sed -i "s/\.rename2\t/\.rename\t\t/" `git grep -wl rename2`
sed -i "s/\brename2\b/rename/g" `git grep -wl rename2`
Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>

This is trivial to do:

 - add flags argument to foo_rename()
 - check if flags doesn't have any other than RENAME_NOREPLACE
 - assign foo_rename() to .rename2 instead of .rename

Filesystems converted:

affs, bfs, exofs, ext2, hfs, hfsplus, jffs2, jfs, logfs, minix, msdos,
nilfs2, omfs, reiserfs, sysvfs, ubifs, udf, ufs, vfat.
Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>
Acked-by: NBoaz Harrosh <ooo@electrozaur.com>
Acked-by: NRichard Weinberger <richard@nod.at>
Acked-by: NBob Copeland <me@bobcopeland.com>
Acked-by: NJan Kara <jack@suse.cz>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Dave Kleikamp <shaggy@kernel.org>
Cc: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Christoph Hellwig <hch@infradead.org>

inode_change_ok() will be resposible for clearing capabilities and IMA
extended attributes and as such will need dentry. Give it as an argument
to inode_change_ok() instead of an inode. Also rename inode_change_ok()
to setattr_prepare() to better relect that it does also some
modifications in addition to checks.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJan Kara <jack@suse.cz>

UBIFS uses full names to work with xattrs, therefore we have to use
xattr_full_name() to obtain the xattr prefix as string.

Cc: <stable@vger.kernel.org>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Fixes: 2b88fc21 ("ubifs: Switch to generic xattr handlers")
Signed-off-by: NRichard Weinberger <richard@nod.at>
Reviewed-by: NAndreas Gruenbacher <agruenba@redhat.com>
Tested-by: Dongsheng Yang <dongsheng081251@gmail.com>

An assertion in layout_in_gaps() verifies that the gap_lebs pointer is
below the maximum bound. When computing this maximum bound the idx_lebs
count is multiplied by sizeof(int), while C pointers arithmetic does take
into account the size of the pointed elements implicitly already. Remove
the multiplication to fix the assertion.

Fixes: 1e51764a ("UBIFS: add new flash file system")
Cc: <stable@vger.kernel.org>
Signed-off-by: NVincent Stehlé <vincent.stehle@intel.com>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>

The wbuf is already sync-ed before ubifs_leb_unmap()
Signed-off-by: NSylvain Etienne <seti@dadboo.eu>
Acked-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NRichard Weinberger <richard@nod.at>