fs: ubifs: Add authentication support ...

This adds UBIFS authentication support. For now, we do not do
any authentication even on authenticated UBIFS images. Since
this behaviour is not what the user normally expects when mounting
authenticated images we only do this when the user explicitly allows
it in "global.ubifs.allow_authenticated_unauthenticated". If the
flag is false then we refuse mounting such an image and return -EPERM
instead.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

fs: Drop trivial .lseek() implementaitons in FS drivers ...

There are no FS drivers that do not implement .lseek callback in the
codebase, so there doesn't seem to exist a use-case where lseek()
would return -ENOSYS due to fsdrv->lseek being NULL. At the same time
a large number of FS drivers implement only the most basic "always
succeeds" custom .lseek() hook.

Change the code of lseek() to treat absense of .lseek() to mean that
no special actions needs to be taken by FS driver and seek is always
successful and drop all of the trivial .lseek() implementations.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

fs: Update FILE position in lseek() ...

Instead on relying on driver callbacks to update 'pos' in FILE, do it
as a part of lseek() code. This allows us to drop a bit of repeating
code as well as making lseek() implementation consistent with write()
and read().

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

fs: ubifs: Avoid missing prototype warning ...

Remove unused ubifs_iput() and make locally used functions static.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

fs: ubifs: optionally allow to mount UBIFS images with encrypted files ...

Currently we do not support the UBIFS file encryption feature.
Nevertheless we can allow read clear files from UBIFS to be
able to boot an unencrypted kernel. This differs from the Kernel
behaviour, so add a globalvar to make that configurable.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ubifs: Update to v4.18-rc6 ...

This syncs the UBIFS code with Linux-4.19-rc6.

There are many functions in the Linux UBIFS codebase that we do not need
for a readonly implementation. These are missing here, but all removed
functions are annotated as such so it should be relatively easy to copy
a newer codebase over the current one and to see which functions shall
be removed from the newer version.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

fs: ubifs: remove not needed code ...

This patch aggressively removes stuff that we do not need in a readonly
implementation:

- write buffering support
- lpt/ltab code
- garbage collector
- everything under #ifndef __BAREBOX__

This decreases the binary size by about 5k on ARM, but the main reason
for doing this is the idea that things that are not there don't need to
be synced with upstream ubifs code.
The __BAREBOX__ ifdeffery makes the code very hard to read and is a
maintenance burden by itself, so it is removed here aswell.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Add kmemdup ...

We have kmemdup as a UBIFS specific variant, put it into the correct
header files. Instead of reimplementing it just use memdup we already
have.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

fs: ubifs: Switch to dentry cache implementation ...

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ubifs: remove dead code ...

Remove code that was added to UBIFS for U-Boot but that is not needed
for barebox.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ubifs: restore symlink support ...

In commit a63059d7 of the latest u-boot port, the function that
returns the inode number also resolves symlink. This prevents the
readlink entry point from doing its job and breaks the user command
readlink and the display of symlink with the ls command.
Remove the code following the link to restore original functionality.

Signed-off-by: Renaud Barbier <renaud.barbier@abaco.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ubifs: check return pointer properly ...

ubifs_iget() returns error codes encoded in the pointer,
so the NULL check will never be true.

Signed-off-by: Lucas Stach <dev@lynxeye.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

string: Fix (v)asprintf prototypes ...

Our asprintf and vasprintf have different prototypes than the glibc
functions. This causes trouble when we want to share barebox code
with userspace code. Change the prototypes for (v)asprintf to match
the glibc prototypes. Since the current (v)asprintf are convenient
to use change the existing functions to b(v)asprintf.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ubifs: update implementation from u-boot v2016.03 ...

This updated code supports recovering from unclean unmounts when write
buffer size is larger than 8. Linux uses takes information into
consideration when checking for writes.
The following list shows the changes for each file done compared to
u-boot v2016.03 code.

Makefile
* Add gc.o, do not include header as in u-boot

budget.c:
* Replace __UBOOT__ with __BAREBOX__

debug.c:
* Replace __UBOOT__ with __BAREBOX__
* Remove #include <linux/compat.h>
* Replace current->pid with 0

debug.h
* Replace __UBOOT__ with __BAREBOX__
* Add "0 &&" to ubifs_assert condition check
  U-Boot essentially disabled pr_crit output and dump_stack() is defined
  to do { } while (0), so ubifs_assert does nothing despite condition.

gc.c:
* Replace __UBOOT__ with __BAREBOX__

io.c:
* Replace __UBOOT__ with __BAREBOX__
* Remove #include <linux/compat.h>

key.h:
* No changes

log.c:
* No changes

lprops.c:
* Replace __UBOOT__ with __BAREBOX__

lpt.c
* Replace __UBOOT__ with __BAREBOX__
* Remove #include <linux/compat.h>
* Remove #include <ubi_uboot.h>

lpt_commit.c
* Replace __UBOOT__ with __BAREBOX__
* Remove #include <linux/compat.h>

master.c
* Replace __UBOOT__ with __BAREBOX__
* Remove #include <linux/compat.h>
* Remove #include <ubi_uboot.h>

misc.h
* Replace __UBOOT__ with __BAREBOX__
* Add #ifndef __BAREBOX__ around unneeded ubifs_current_time

orphan.c
* No changes

recovery.c
* Replace __UBOOT__ with __BAREBOX__

replay.c
* Replace __UBOOT__ with __BAREBOX__
* Remove #include <linux/compat.h>

sb.c
* Replace __UBOOT__ with __BAREBOX__
* Remove #include <linux/compat.h>
* Remove #include <ubi_uboot.h>
* rp_uid and rp_gid are still uid_t, not kuid_t, so remove .val

scan.c
* Replace __UBOOT__ with __BAREBOX__

super.c:
* Replaced current->pid with 0
* Replaced __UBOOT__ with __BAREBOX__
* Removed #include <ubi_uboot.h>
* Removed #include <memalign.h>
* Added #include <init.h>
* Replaced malloc_cache_aligned with kzalloc
* Replaced I_LOCK with I_SYNC
* i_uid and i_gid are still uid_t, not kuid_t, so remove .val
* Replaced string "U-Boot" with "Barebox"
* Add #ifndef __BAREBOX__ around open_ubi, sb_test, sb_set, ubifs_mount,
  kill_ubifs_super, ubifs_fs_type
* Do not call ubi_open_volume or ubi_close_volume in ubifs_fill_super
  Those will already be handled in ubifs_probe
* Replaced uboot_ubifs_mount with new ubifs_get_super implementation using
  existing functions alloc_super, alloc_ubifs_info

tnc.c
* Replace __UBOOT__ with __BAREBOX__
* Remove #include <linux/compat.h>

tnc_misc.c
* Replace __UBOOT__ with __BAREBOX__

ubifs-media.h
* Replace __UBOOT__ with __BAREBOX__

ubifs.c:
* Replaced __UBOOT__ with __BAREBOX__
* Adjusted header includes
* Removed DECLARE_GLOBAL_DATA_PTR
* Add static struct z_stream_s variable
* Add struct ubifs_priv delcaration
* Replaced zunzip with deflate_decompress call
* Add ifdef for disabling ZLIB and/or LZO support
* Replaced malloc_cache_aligned with kzalloc
* Added #ifndef __BAREBOX__ around filldir, ubifs_printdir,
  ubifs_set_blk_dev, ubifs_ls, ubifs_exists, ubifs_size, do_readpage,
  ubifs_read, ubifs_close, ubifs_load
* Make parameter filename const char* in ubifs_findfile
* Add UBIFS fs_driver_d implementation
* Add zlib_decomp_init, ubifs_init

ubifs.h:
* Replaced __UBOOT__ with __BAREBOX__
* Adjusted header includes
* Added old #define crc32
* Added helper around kmem*
* Added XATTR_LIST_MAX define
* Added #ifndef __BAREBOX__ around current_fs_time struct inode,
  struct super_block, file_system_type, dentry and friends which barebox
  already has
* Added #ifndef __BAREBOX__ around write_inode in super_operations to avoid
  declaration of writeback_control
* Change rp_uid and rp_gid to uid_t and gui_t
* Added struct device_d to struct ubifs_info
* Added forward declaration of ubifs_get_super

linux/fs.h:
* Make struct inode's i_nlink a union containing a non-const int __i_nlink
  while making i_nlink a const int

linux/fs.h:
* Add s_remove_count

linux/fs.h:
* Convert struct super_block.s_instances and
  struct file_system_type.fs_supers to hlist_head

Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ubifs: Fix reading holes in files ...

When a whole block of 4KiB in an ubifs file is zero then the block is
not stored in the filesystem. read_block() returns -ENOENT in this case,
so this return value must be treated as success.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

introduce strerrorp ...

putting an error pointer into strerror can be a bit confusing since
strerror takes a positive error code but PTR_ERR returns a negative
number, so we have to do strerror(-PTR_ERR(errp)). Some places got
this wrong already, so introduce a strerrorp function which directly
takes an error pointer.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

fs: ubifs: Implement Linux rootarg ...

Add the parameter to boot from ubifs fileystems. This assumes that
there will be only one UBI device registered in the kernel, otherwise
there is no way to predict the ubi number.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

fs: rename inode member of struct filep to priv ...

Because that's what it is. 'inode' will become confusing
once we support real inodes.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ubifs: Remove unused variable ...

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

fs: ubifs: rework logging ...

By default UBIFS is very verbose. Decrease the verbosity, turn
printf messages into ubifs_ messages and add device parameters
for the values which are not printed anymore.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

fs: ubifs: Fix unused function warning ...

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

UBIFS: implement readlink entry point ...

Implement the readlink entry point for future use by the DA923RC.

Signed-off-by: Renaud Barbier <renaud.barbier@ge.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

fs: cleanup backingstore handling ...

All filesystem drivers which need a backingstore device do the same
ignoring of '/dev/' in the backingstore followed by a cdev_open. Add a
helper function for it and let the core handle the cdev. As a side
effect this makes sure that fsdev->cdev is also set when a device is
mounted without the leading '/dev/' which was previously ignored
by the mount code.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

fs: Add ubifs support ...

This adds ubifs support from u-boot-2013.07. This is taken
mostly as-is, only the necessary adjustments to attach to the
barebox fs layer have been made.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>