libfile: open_and_lseek: enlarge small files enough to make lseek possible ...

This makes the following do the expected thing:

	barebox@barebox sandbox:/ ls -l lala
	-rwxrwxrwx              4 lala
	barebox@barebox sandbox:/ mw -d lala 72 0

Without this patch mw dies with

	lseek: Invalid argument

memset, memcpy and probably others benefit in the same way.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

libfile: open_and_lseek: don't imply O_RDONLY ...

There are several users that pass O_RDWR or O_WRONLY in mode to
open_and_lseek() and use the resulting file descriptor for writing. This
is no real issue becauce O_RDONLY is 0 and so can be dropped without
any side effects.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

libfile: implement new helper write_file_flash() ...

Compared to write_file() this new function also calls erase() to be
suitable for flash devices.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Merge branch 'for-next/tftp-workaround'

libfile: Make write_file buffer const ...

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

libfile: implement a function to cache a file ...

Due to the nature of TFTP which can't lseek and due to the silliness
of our filesystem implementation which can't cache accesses we have to
manually cache files on TFTP filesystems sometimes. Make it easier
for them by providing a cache_file() function which copies the file
from TFTP to RAM.

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

libfile: implement make_temp ...

Create a make_temp() function which creates a name for a temporary file.
Since we do not have any concurrency in barebox we do not need to create
the file right away and can leave that to the caller. Unlike unix
mktemp the resulting filename is dynamically allocated and must be
freed by the caller.

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

lib: libfile: Fix copying files to a non existing destination ...

If the destination file does not exist the stat call to check the file
type fails. Extend the check of the stat return value.
To allow to copy files to a new destination.

Fixes commit 0ec6bd3e1be8 ("libfile: copy_file: Only open
regular files with O_TRUNC")

Signed-off-by: Teresa Remmet <t.remmet@phytec.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

libfile: copy_file: Only open regular files with O_TRUNC ...

Device files can not truncate in the most cases. Check if the
destination is a regular file and open only those with O_TRUNC.

Signed-off-by: Teresa Remmet <t.remmet@phytec.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

libfile: Change write_full to be have const buf ...

write() uses a const pointer so write_full should do the same.

Signed-off-by: Markus Pargmann <mpa@pengutronix.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>

libfile: move open_and_lseek() to libfile ...

libfile is a collection of helpers for handling files. open_and_lseek()
is a perfect match for this, so move it there.

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

lib: libfile: Do not ignore errors in close() ...

Some character devices may perform meaningful operations in their
implementation of close() -- a good example would be socfpga.c which
checks if the FPGA was programmed succesfully in it's close() method
-- so ignoring return value of this call may cause false positives in
checking exit status for success.

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

read_file_2(): drop unnecessary 'else' ...

Signed-off-by: Alexander Smirnov <alllecs@yandex.ru>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

libfile: Add copy_recursive ...

To recursively copy a directory tree.

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

libfile: add compare_file function ...

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

read_file_2: Fix return value ...

Set return value correct in error case.
This prevents barebox from crashing in some conditions.

Signed-off-by: Teresa Gámez <t.gamez@phytec.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

read_file: introduce read_file_2 ...

read_file has some limitations:

- It is not possible to check the error code since read_file returns
  NULL for failure
- It is not possible to limit the buffer size to sensible limits.

This patch introduces read_file_2 which doesn't have these limitations.
read_file becomes a wrapper around read_file_2.

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

move file helper functions to separate file ...

We have our file helper functions in several places. Move them
all to lib/libfile.c.
With this we no longer have file helpers in fs/fs.c which contains
the core fs functions and no functions in lib/libbb.c which are
not from busybox.

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