treewide: remove references to CREDITS ...

The CREDITS file was removed from barebox in 2015 by commit 6570288f2d97
("Remove the CREDITS file"). Remove references to it from several files.

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

fs: ext4: return NULL instead of 0 ...

ext4fs_get_extent_block() returns a pointer, so return NULL instead of
integer 0.

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

fs: ext4: Fix handling of sparse files ...

Adoption of U-Boot commit:

| commit f81db56
| Author: Stefan Brüns <stefan.bruens@rwth-aachen.de>
| Date:   Sat Nov 5 22:17:14 2016 +0100
|
|     ext4: Fix handling of sparse files
|
|     A sparse file may have regions not mapped by any extents, at the start
|     or at the end of the file, or anywhere between, thus not finding a
|     matching extent region is never an error.
|
|     Found by python filesystem tests.

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

fs: ext4: remove unnecessarily clever file read ...

ext4fs_read_file() tries to tries to bundle contiguous block reads into
longer reads from the device. In barebox we cache in the block layer
already, so this is unnecessary. Simplify the code by removing the
bundled reads.

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

fs: ext4: Fix out of bounds memset ...

When a block we read is a sparse block, we memset the corresponding
output buffer to zero. If that block is the last block we read, we
may not memset the whole block, but only up to the length of the output
buffer, which may be shorter than a full block.

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

trivial: fix typo lenght -> length ...

Generated by

	perl -p -i -e 's/lenghte?/length/' arch/arm/boards/chumby_falconwing/falconwing.c arch/arm/mach-samsung/mem-s3c64xx.c fs/ext4/ext_common.h lib/gui/lodepng.c include/jtag.h

There is another instance in dts/Bindings/usb/s3c2410-usb.txt, this is
fixed in Linux v5.3-rc1 so supposed to be fixed soon in barebox, too.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
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: ext4: Switch to dentry cache implementation ...

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

fs: dentry cache implementation ...

This adds the Linux dentry cache implementation to barebox.

Until now every filesystem driver resolves the full path to a file for
itself. This leads to code duplication and is error prone since
resolving paths is a complicated task. Also it can narrow down the
lookup performance since barebox only knows ASCII paths and has no way
of caching lookups.

With this patch we get the Linux dcache implementation. The path
resolving code from fs/namei.c is nearly taken as-is, minus the RCU
and locking code. Dcaching is made simple as of now: We simply cache
everything and never release any dentries. Although we do reference
counting for inodes and dentries it is effectively not used yet.
We never free anything until a fs is unmounted in which case we free
everything no matter if references are taken or not.

This patch also contains a wrapper in fs/legacy.c to support
filesystems with the old API.

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

ext4: Use correct descriptor size when reading the block group descriptor ...

This is an adoption of the U-Boot commit

| commit f798b1d
| Author: Stefan Brüns <stefan.bruens@rwth-aachen.de>
| Date:   Sat Sep 17 02:10:09 2016 +0200
|
|     ext4: Use correct descriptor size when reading the block group descriptor
|
|     The correct descriptor size must be used when calculating offsets, and
|     also to read the correct amount of data.
|
|     Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ext4: determine group descriptor size for 64bit feature ...

This is an adoption of the U-Boot commits

| commit fc214ef
| Author: Stefan Brüns <stefan.bruens@rwth-aachen.de>
| Date:   Sat Sep 17 02:10:07 2016 +0200
|
|     ext4: determine group descriptor size for 64bit feature
|
|     If EXT4_FEATURE_INCOMPAT_64BIT is set, the descriptor can be read from
|     the superblocks, otherwise it defaults to 32.
|
|     Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>

| commit 3cc5bbb
| Author: Stefan Brüns <stefan.bruens@rwth-aachen.de>
| Date:   Tue Dec 27 02:35:08 2016 +0100
|
|     fs/ext4: Initialize group descriptor size for revision level 0 filesystems
|
|     genext2fs creates revision level 0 filesystems, which are not readable
|     by u-boot due to the initialized group descriptor size field.
|     f798b1d
|
|     Reported-by: Kever Yang <kever.yang@rock-chips.com>
|     Reported-by: FrostyBytes@protonmail.com
|     Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
|     Tested-by: Kever Yang <kever.yang@rock-chips.com>

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ext4: Update ext2/3/4 superblock, group descriptor and inode structures ...

This is an adoption of the U-Boot commit

| commit 3ee2f97
| Author: Stefan Brüns <stefan.bruens@rwth-aachen.de>
| Date:   Sat Sep 17 02:10:06 2016 +0200
|
|     ext4: Update ext2/3/4 superblock, group descriptor and inode structures
|
|     Most importantly, the superblock provides the used group descriptor size,
|     which is required for the EXT4_FEATURE_INCOMPAT_64BIT.
|
|     Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ext4: fix wrong usage of le32_to_cpu() ...

This is an adoption of the U-Boot commit

| commit 011bc33
| Author: Michael Walle <michael@walle.cc>
| Date:   Mon Aug 29 10:46:46 2016 +0200
|
|     ext4: fix wrong usage of le32_to_cpu()
|
|     le32_to_cpu() must only convert the revision_level and not the boolean
|     result.
|
|     Signed-off-by: Michael Walle <michael@walle.cc>

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ext4: drop unused and misdefined INODE_SIZE_FILESYSTEM macro ...

Nota bene sblock.inode_size actually has __le16 type.

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ext4: use kernel names for byte swaps ...

This is an adoption of the U-Boot commit

| commit 7f101be
| Author: Michael Walle <michael@walle.cc>
| Date:   Mon Aug 29 10:46:44 2016 +0200
|
|     ext4: use kernel names for byte swaps
|
|     Instead of __{be,le}{16,32}_to_cpu use {be,le}{16,32}_to_cpu.
|
|     Signed-off-by: Michael Walle <michael@walle.cc>

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ext4: change structure fields to __le/__be types ...

This is an adoption of the U-Boot commit

| commit 2a0b7a9
| Author: Michael Walle <michael@walle.cc>
| Date:   Mon Aug 29 10:46:43 2016 +0200
|
|     ext4: change structure fields to __le/__be types
|
|     Change all the types of ext2/4 fields to little endian types and all the
|     JBD fields to big endian types. Now we can use sparse (make C=1) to check
|     for statements where we need byteswaps.
|
|     Signed-off-by: Michael Walle <michael@walle.cc>

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

fs: ext4: fix symlink read function ...

From U-Boot commit:

| commit 37f2388
| Author: Ronald Zachariah <rozachar@cisco.com>
| Date:   Thu Apr 28 07:08:34 2016 +0200
|
|     fs: ext4: fix symlink read function
|
|     The function ext4fs_read_symlink was unable to handle a symlink
|     which had target name of exactly 60 characters.
|
|     Signed-off-by: Ronald Zachariah <rozachar@cisco.com>
|     Signed-off-by: Stefan Roese <sr@denx.de>
|     Reviewed-by: Stephen Warren <swarren@nvidia.com>
|     Cc: Tom Rini <trini@konsulko.com>

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

fs: ext4: make locally used ext4fs_get_indir_block() static ...

The patch fixes this compiler's warning:

      CC      fs/ext4/ext4_common.o
    fs/ext4/ext4_common.c:130:5: warning: no previous prototype for
    'ext4fs_get_indir_block' [-Wmissing-prototypes]
     int ext4fs_get_indir_block(struct ext2fs_node *node, struct
    ext4fs_indir_block *indir, int blkno)
         ^

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

fs: import magic.h from Linux kernel ...

include/linux/magic.h provides MAGIC numbers for various
file systems.

Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

drop <stddef.h> includes ...

The compilers stddef.h should not be included. We declare all types
ourselves.

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>

fs: ext4: le32_to_cpu() used on a 16-bit field ...

From U-Boot commit:

| commit 8b415f7
| Author: Rommel Custodio <sessyargc+uboot@gmail.com>
| Date:   Sun Jul 21 10:53:25 2013 +0200
|
|     ext4fs: le32_to_cpu() used on a 16-bit field
|
|     Fix reading ext4_extent_header struture on BE machines.  Some 16 bit
|     fields where converted to 32 bit fields, due to the byte swap on BE
|     machines the containing value was corrupted. Therefore reading ext4
|     filesystems on BE machines where broken before.
|
|     Signed-off-by: Rommel Custodio <sessyargc+uboot@gmail.com>
|     [sent via git-send-email; rework commit message]
|     Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>
|     Reviewed-by: Simon Glass <sjg@chromium.org>
|     Tested-by: Simon Glass <sjg@chromium.org>
|     Tested-by: Lukasz Majewski <l.majewski@samsung.com>

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

fs: ext4: use EXT2_BLOCK_SIZE instead of fs->blksz ...

From U-Boot commit:

| commit 4701732
| Author: Ionut Nicu <ioan.nicu.ext@nsn.com>
| Date:   Mon Jan 13 11:59:24 2014 +0100
|
|     ext4fs: use EXT2_BLOCK_SIZE instead of fs->blksz
|
|     Using fs->blksz in ext4fs_get_extent_block() is not
|     correct since fs->blksz is not initialized on the
|     read path. Use EXT2_BLOCK_SIZE() instead which will
|     produce the desired output.
|
|     Signed-off-by: Ionut Nicu <ioan.nicu.ext@nsn.com>
|     Signed-off-by: Mathias Rulf <mathias.rulf@nsn.com>

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

fs: ext4: fix "invalid extent block" error ...

From U-Boot commit:

| commit b5bbac1
| Author: Ionut Nicu <ioan.nicu.ext@nsn.com>
| Date:   Mon Jan 13 12:00:08 2014 +0100
|
|     ext4fs: fix "invalid extent block" error
|
|     For files where we actually have extent indexes following
|     an extent header (ext_block->eh_depth != 0), the do/while
|     loop from ext4fs_get_extent_block() does not select the
|     proper extent index structure.
|
|     For example, if we have:
|
|     ext_block->eh_depth = 1
|     ext_block->eh_entries = 1
|     fileblock = 0
|     index[0].ei_block = 0
|
|     the do/while loop will exit with i set to 0 and the
|     ext4fs_get_extent_block() function will return 0, even if
|     there was a valid extent index structure following the
|     header.
|
|     Signed-off-by: Ionut Nicu <ioan.nicu.ext@nsn.com>
|     Signed-off-by: Mathias Rulf <mathias.rulf@nsn.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>

ext4: switch debug and printf to dev_xxx ...

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

fs: implement initial ext4 support from U-Boot ...

The ext4 implementation has been taken from U-Boot with some
changes:

- No global variables to allow for multiple filesystems to
  be mounted and multiple files to be open.
- remove fs internal link following and use the barebox link
  implementation.
- remove write support. This is incomplete in U-Boot, so I decided
  to skip this for now.

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