Commit Graph

86 Commits

Author SHA1 Message Date
Stefan Brüns 3cc5bbb8e6 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.
f798b1dda1

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>
2016-12-27 11:24:18 -05:00
Stefan Brüns 66a47ff2d8 ext4: Allow reading files with non-zero offset, clamp read len
Support was already implemented, but not hooked up. This fixes several
fails in the test cases.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
2016-11-21 14:07:27 -05:00
Stefan Brüns f81db56f2f 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: Stefan Brüns <stefan.bruens@rwth-aachen.de>
2016-11-21 14:07:27 -05:00
Stefan Brüns 805e3e00f2 ext4: Only write journal entries for modified blocks in unlink_filename
Instead of creating a journal entry for each directory block, even
if the block is unmodified, only log the modified block.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Lukasz Majewski <l.majewski@samsung.com>
2016-10-24 08:04:37 -04:00
Stefan Brüns d1bdf22461 ext4: Fix handling of direntlen in unlink_filename
The direntlen checks were quite bogus, i.e. the loop termination used
"len + offset == blocksize" (exact match only), and checked for a
direntlen less than 0. The latter can never happen as the len is
unsigned, this has been reported by Coverity, CID 153384.

Use the same code as in search_dir for directory traversal. This code
has the correct checks for direntlen >= sizeof(struct dirent), and
offset < blocksize.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Reported-by: Coverity (CID: 153383, 153384)
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Lukasz Majewski <l.majewski@samsung.com>
2016-10-24 08:04:36 -04:00
Stefan Brüns 15bf8c4f93 ext4: cleanup unlink_filename function
Use the same variable names as in search_dir, to make purpose of variables
more obvious.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Reviewed-by: Tom Rini <trini@konsulko.com>
2016-10-24 08:04:36 -04:00
Masahiro Yamada 1221ce459d treewide: replace #include <asm/errno.h> with <linux/errno.h>
Now, arch/${ARCH}/include/asm/errno.h and include/linux/errno.h have
the same content.  (both just wrap <asm-generic/errno.h>)

Replace all include directives for <asm/errno.h> with <linux/errno.h>.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
[trini: Fixup include/clk.]
Signed-off-by: Tom Rini <trini@konsulko.com>
2016-09-23 17:55:42 -04:00
Stefan Brüns b4976b49a0 ext4: Revert rejection of 64bit enabled ext4 fs
Enable mounting of ext4 fs with 64bit feature, as it is supported now.
These had been disabled in 6f94ab6656.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
2016-09-23 09:20:16 -04:00
Stefan Brüns 749e93ee18 ext4: Respect group descriptor size when adjusting free counts
Also adjust high 16/32 bits when free inode/block counts are modified.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
2016-09-23 09:20:16 -04:00
Stefan Brüns 688d0e79f6 ext4: Use helper function to access group descriptor and its fields
The descriptor size is variable, thus array indices are not generically
applicable. The larger group descriptors also contain e.g. high parts
of block numbers, which have to be read and written.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
2016-09-23 09:20:15 -04:00
Stefan Brüns f798b1dda1 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>
2016-09-23 09:18:57 -04:00
Stefan Brüns 9f5dd8b6e2 ext4: Add helper functions for block group descriptor field access
The helper functions encapsulate access of the block group descriptors,
independent of group descriptor size. The helpers also deal with the
endianess of the fields, and with split fields like free_blocks/
free_blocks_high.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
2016-09-23 09:18:56 -04:00
Stefan Brüns fc214ef909 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>
2016-09-23 09:18:56 -04:00
Stefan Brüns b1edcf0d80 ext4: Fix memory leak of journal buffer if block is updated multiple times
If the same block is updated multiple times in a row during a single
file system operation, gd_index is decremented to use the same journal
entry again. Avoid loosing the already allocated buffer.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
2016-09-23 09:02:44 -04:00
Stefan Brüns de9e831675 ext4: Correct block number handling, empty block vs. error code
read_allocated block may return block number 0, which is just an indicator
a chunk of the file is not backed by a block, i.e. it is sparse.

During file deletions, just continue with the next logical block, for other
operations treat blocknumber <= 0 as an error.

For writes, blocknumber 0 should never happen, as U-Boot always allocates
blocks for the whole file.  Reading already handles this correctly, i.e. the
read buffer is 0-fillled.

Not treating block 0 as sparse block leads to FS corruption, e.g.
	./sandbox/u-boot -c 'host bind 0 ./sandbox/test/fs/3GB.ext4.img ;
		ext4write host 0 0 /2.5GB.file 1 '
The 2.5GB.file from the fs test is actually a sparse file.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
2016-09-23 09:02:44 -04:00
Stefan Brüns b779e0290a ext4: remove duplicated block release code for extents
The data blocks are identical for files using traditional direct/indirect
block allocation scheme and extent trees, thus this code part can be
common. Only the code to deallocate the indirect blocks to record the
used blocks has to be seperate, respectively the code to release extent
tree index blocks.

Actually the code to release the extent tree index blocks is still missing,
but at least add a FIXME at the appropriate place.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
2016-09-23 09:02:43 -04:00
Stefan Brüns 87f9fdc08d ext4: initialize full inode for inodes bigger than 128 bytes
Make sure the the extra_isize field (offset 128) is initialized to 0, to
mark any extra data as invalid.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Reviewed-by: Lukasz Majewski <l.majewski@samsung.com>
2016-09-23 09:02:42 -04:00
Stefan Brüns 290ce2f95a ext4: Use correct value for inode size even on revision 0 filesystems
fs->inodesz is already correctly (i.e. dependent on fs revision)
initialized in ext4fs_mount.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Reviewed-by: Lukasz Majewski <l.majewski@samsung.com>
2016-09-23 09:02:42 -04:00
Stefan Brüns 87a40b6e03 ext4: Fix memory leak in case of failure
temp_ptr should always be freed, even if the function is left via
goto fail.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Reviewed-by: Lukasz Majewski <l.majewski@samsung.com>
2016-09-23 09:02:41 -04:00
Stefan Brüns 0ceef3d371 ext4: Avoid out-of-bounds access of block bitmap
If the blocksize is 1024, count is initialized with 1. Incrementing count
by 8 will never match (count == fs->blksz * 8), and ptr may be
incremented beyond the buffer end if the bitmap is filled. Add the
startblock offset after the loop.

Remove the second loop, as only the first iteration will be done.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Reviewed-by: Lukasz Majewski <l.majewski@samsung.com>
2016-09-23 09:02:40 -04:00
Stefan Brüns a9fa0ed183 ext4: After completely filled group, scan next group from the beginning
The last free block of a block group may be in its middle. After it has
been allocated, the next block group should be scanned from its beginning.

The following command triggers the bad behaviour (on a blocksize 1024 fs):

./sandbox/u-boot -c 'i=0; host bind 0 ./disk.raw ;
	while test $i -lt 260 ; do echo $i; setexpr i $i + 1;
		ext4write host 0:2 0 /X${i} 0x1450; done ;
	ext4write host 0:2 0 /X240 0x2000 ; '

When 'X240' is extended from 5200 byte to 8192 byte, the new blocks should
start from the first free block (8811), but it uses the blocks 8098-8103
and 16296-16297 -- 8103 + 1 + 8192 = 16296. This can be shown with
debugfs, commands 'ffb' and 'stat X240'.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Reviewed-by: Lukasz Majewski <l.majewski@samsung.com>
2016-09-23 09:02:40 -04:00
Stefan Brüns e927265225 ext4: Do not clear zalloc'ed buffers a second time
zero_buffer is never written, thus clearing it is pointless.
journal_buffer is completely initialized by ext4fs_devread (or in case
of failure, not used).

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Reviewed-by: Lukasz Majewski <l.majewski@samsung.com>
2016-09-23 09:02:39 -04:00
Stefan Brüns 398d6fad92 ext4: Only update number of of unused inodes if GDT_CSUM feature is set
e2fsck warns about "Group descriptor 0 marked uninitialized without
feature set."
The bg_itable_unused field is only defined if FEATURE_RO_COMPAT_GDT_CSUM
is set, and should be set (kept) zero otherwise.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Reviewed-by: Lukasz Majewski <l.majewski@samsung.com>
2016-09-23 09:02:39 -04:00
Stefan Brüns b7dd40d052 ext4: Scan all directory blocks when looking up an entry
Scanning only the direct blocks of the directory file may falsely report
an existing file as nonexisting, and worse can also lead to creation
of a duplicate entry on file creation.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Reviewed-by: Lukasz Majewski <l.majewski@samsung.com>
2016-09-23 09:02:38 -04:00
Stefan Brüns 10a7a1b8ba ext4: Avoid corruption of directories with hash tree indexes
While directories can be read using the old linear scan method, adding a
new file would require updating the index tree (alternatively, the whole
tree could be removed).

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Reviewed-by: Lukasz Majewski <l.majewski@samsung.com>
2016-09-23 09:02:37 -04:00
Stefan Brüns a321abd54f ext4: Scan all directory blocks for space when inserting a new entry
Previously, only the last directory block was scanned for available space.
Instead, scan all blocks back to front, and if no sufficient space is
found, eventually append a new block.
Blocks are only appended if the directory does not use extents or the new
block would require insertion of indirect blocks, as the old code does.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Reviewed-by: Lukasz Majewski <l.majewski@samsung.com>
2016-09-23 09:02:36 -04:00
Stefan Brüns b96c3c7292 ext4: Do not crash when trying to grow a directory using extents
The following command crashes u-boot:
./sandbox/u-boot -c 'i=0; host bind 0 ./sandbox/test/fs/3GB.ext4.img ;
  while test $i -lt 200 ; do echo $i; setexpr i $i + 1;
  ext4write host 0 0 /foobar${i} 0; done'

Previously, the code updated the direct_block even for extents, and
fortunately crashed before pushing garbage to the disk.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Reviewed-by: Lukasz Majewski <l.majewski@samsung.com>
2016-09-23 09:02:36 -04:00
Stefan Brüns a0d767e2c1 ext4: propagate error if creation of directory entry fails
In case the dir entry creation failed, ext4fs_write would later overwrite
a random inode, as inodeno was never initialized.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Reviewed-by: Lukasz Majewski <l.majewski@samsung.com>
2016-09-23 09:02:35 -04:00
Stefan Brüns 76a29519ff ext4: fix possible crash on directory traversal, ignore deleted entries
The following command triggers a segfault in search_dir:
./sandbox/u-boot -c 'host bind 0 ./sandbox/test/fs/3GB.ext4.img ;
    ext4write host 0 0 /./foo 0x10'

The following command triggers a segfault in check_filename:
./sandbox/u-boot -c 'host bind 0 ./sandbox/test/fs/3GB.ext4.img ;
    ext4write host 0 0 /. 0x10'

"." is the first entry in the directory, thus previous_dir is NULL. The
whole previous_dir block in search_dir seems to be a bad copy from
check_filename(...). As the changed data is not written to disk, the
statement is mostly harmless, save the possible NULL-ptr reference.

Typically a file is unlinked by extending the direntlen of the previous
entry. If the entry is the first entry in the directory block, it is
invalidated by setting inode=0.

The inode==0 case is hard to trigger without crafted filesystems. It only
hits if the first entry in a directory block is deleted and later a lookup
for the entry (by name) is done.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Reviewed-by: Lukasz Majewski <l.majewski@samsung.com>
2016-09-23 09:02:34 -04:00
Michael Walle 011bc3342a 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>
2016-09-23 09:02:05 -04:00
Michael Walle 58a9ecbaf4 ext4: fix endianess problems in ext4 write support
All fields were accessed directly instead of using the proper byte swap
functions. Thus, ext4 write support was only usable on little-endian
architectures. Fix this.

Signed-off-by: Michael Walle <michael@walle.cc>
2016-09-23 09:02:04 -04:00
Michael Walle 7f101be314 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>
2016-09-23 09:02:02 -04:00
Michael Walle 2a0b7a971a 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>
2016-09-23 09:02:01 -04:00
Tom Rini 6f94ab6656 ext4: Refuse to mount filesystems with 64bit feature set
With e2fsprogs after 1.43 the 64bit and metadata_csum features are
enabled by default.  The metadata_csum feature changes how
ext4_group_desc->bg_checksum is calculated, which would break write
support.  The 64bit feature however introduces changes such that it
cannot be read by implementations that do not support it.  Since we do
not support this, we must not mount it.

Cc: Stephen Warren <swarren@nvidia.com>
Cc: Simon Glass <sjg@chromium.org>
Cc: Lukasz Majewski <l.majewski@samsung.com>
Cc: Stefan Roese <sr@denx.de>
Reported-by: Andrew Bradford <andrew.bradford@kodakalaris.com>
Signed-off-by: Tom Rini <trini@konsulko.com>
2016-08-05 07:27:14 -04:00
Ronald Zachariah 37f23885e4 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>
2016-05-02 13:33:19 -04:00
Simon Glass 2a981dc2c6 dm: block: Adjust device calls to go through helpers function
To ease conversion to driver model, add helper functions which deal with
calling each block device method. With driver model we can reimplement these
functions with the same arguments.

Use inline functions to avoid increasing code size on some boards.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
2016-03-14 15:34:50 -06:00
Simon Glass 4101f68792 dm: Drop the block_dev_desc_t typedef
Use 'struct' instead of a typdef. Also since 'struct block_dev_desc' is long
and causes 80-column violations, rename it to struct blk_desc.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
2016-03-14 15:34:50 -06:00
Tom Rini 495c3a1e22 ext4_common.c: Clean up failure cases in alloc_triple_indirect_block
As noted by Coverity, when we have an error in
alloc_triple_indirect_block we will leak ti_pbuff_start_addr as it's not
being freed.  Further inspection here shows that we could also leak
ti_cbuff_start_addr in one corner case so free that as well.

Reported-by: Coverity (CID 131205, 131206)
Signed-off-by: Tom Rini <trini@konsulko.com>
2016-01-13 21:05:20 -05:00
Stephen Warren 7c4213f6a5 block: pass block dev not num to read/write/erase()
This will allow the implementation to make use of data in the block_dev
structure beyond the base device number. This will be useful so that eMMC
block devices can encompass the HW partition ID rather than treating this
out-of-band. Equally, the existence of the priv field is crying out for
this patch to exist.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
2016-01-13 21:05:18 -05:00
Thomas Fitzsimmons 54d68e9333 fs: ext4: Prevent infinite loop in ext4fs_iterate_dir
If the ext3 journal gets out of sync with what is written on disk, for
example because of an unexpected power cut, ext4fs_read_file can
return an all-zero directory entry.  In that case, ext4fs_iterate_dir
would infinite loop.

This patch detects when a directory entry's direntlen member is 0 and
returns a failure status, which breaks out of the infinite loop.  As a
result, U-Boot will not find files that may subsequently be recovered
when the journal is replayed.

This is better behaviour than hanging in an infinite loop, but as a
further improvement maybe U-Boot could interpret the ext3 journal and
actually find the unsynced entries.

Signed-off-by: Thomas Fitzsimmons <fitzsim@cisco.com>
Reviewed-by: Stefan Roese <sr@denx.de>
2015-11-23 11:01:52 -05:00
Gary Bisson 9d2f6a9ae7 fs: ext4: fix symlink read function
Since last API changes for files >2GB, the read of symlink is broken as
ext4fs_read_file now returns 0 instead of the length of the actual read.

Signed-off-by: Gary Bisson <gary.bisson@boundarydevices.com>
2015-09-11 17:15:29 -04:00
Stephen Warren d56b2015e6 ext4: fix leak in check_filename()
root_first_block_buffer should be free()d in all cases, not just when an
error occurs. Fix the success exit path of the function to do this.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Lukasz Majewski <l.majewski@samsung.com>
Tested-by: Lukasz Majewski <l.majewski@samsung.com>
2015-09-11 17:15:23 -04:00
Stephen Warren 934b14f2bb ext4: free allocations by parse_path()
parse_path() malloc()s the entries in the array it's passed. Those
allocations must be free()d by the caller, ext4fs_get_parent_inode_num().
Add code to do this.

For this to work, all the array entries must be dynamically allocated,
rather than a mix of dynamic and static allocations. Fix parse_path() not
to over-write arr[0] with a pointer to statically allocated data.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Lukasz Majewski <l.majewski@samsung.com>
Tested-by: Lukasz Majewski <l.majewski@samsung.com>
2015-09-11 17:15:22 -04:00
Stephen Warren 676505f5ce ext4: avoid calling ext4fs_mount() twice, which leaks
ext4_write_file() is only called from the "fs" layer, which calls both
ext4fs_mount() and ext4fs_close() before/after calling ext4_write_file().
Fix ext4_write_file() not to call ext4fs_mount() again, since the mount
operation malloc()s some RAM which is leaked when a second mount call
over-writes the pointer to that data, if no intervening close call is
made.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Lukasz Majewski <l.majewski@samsung.com>
Tested-by: Lukasz Majewski <l.majewski@samsung.com>
2015-09-11 17:15:22 -04:00
Simon Glass cf92e05c01 Move ALLOC_CACHE_ALIGN_BUFFER() to the new memalign.h header
Now that we have a new header file for cache-aligned allocation, we should
move the stack-based allocation macro there also.

Signed-off-by: Simon Glass <sjg@chromium.org>
2015-09-11 17:15:20 -04:00
Przemyslaw Marczak 22b7509efb fs: ext4 write: return file len on success
After rework of the file system API, the size of ext4
write was missed. This causes printing unreliable write
size at the end of the file system write operation.

Signed-off-by: Przemyslaw Marczak <p.marczak@samsung.com>
Cc: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
Cc: Lukasz Majewski <l.majewski@samsung.com>
Cc: Simon Glass <sjg@chromium.org>
Tested-by: Stephen Warren <swarren@nvidia.com>
2015-03-05 20:49:42 -05:00
Tom Rini 9e374e7b72 fs/ext4/ext4fs.c, fs/fs.c fs/fat/fat_write.c: Adjust 64bit math methods
The changes to introduce loff_t into filesize means that we need to do
64bit math on 32bit platforms.  Make sure we use the right wrappers for
these operations.

Cc: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Cc: Suriyan Ramasami <suriyan.r@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Rini <trini@ti.com>
Tested-by: Pierre Aubert <p.aubert@staubli.com>
2014-12-01 15:21:57 -05:00
Suriyan Ramasami d455d8789d fs: API changes enabling extra parameter to return size of type loff_t
The sandbox/ext4/fat/generic fs commands do not gracefully deal with files
greater than 2GB. Negative values are returned in such cases.

To handle this, the fs functions have been modified to take an additional
parameter of type "* loff_t" which is then populated. The return value
of the fs functions are used only for error conditions.

Signed-off-by: Suriyan Ramasami <suriyan.r@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
[trini: Update board/gdsys/p1022/controlcenterd-id.c,
drivers/fpga/zynqpl.c for changes]
Signed-off-by: Tom Rini <trini@ti.com>
2014-11-23 06:49:04 -05:00
Suriyan Ramasami 9f12cd0e06 ext4: Prepare API change for files greater than 2GB
Change the internal EXT4 functions to use loff_t for offsets.

Signed-off-by: Suriyan Ramasami <suriyan.r@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
[trini: Update common/spl/spl_ext.c]
Signed-off-by: Tom Rini <trini@ti.com>
2014-11-23 06:49:04 -05:00
Christian Gmeiner 59e890ef7b fs: make it possible to read the filesystem UUID
Some filesystems have a UUID stored in its superblock. To
allow using root=UUID=... for the kernel command line we
need a way to read-out the filesystem UUID.

changes rfc -> v1:
 - make the environment variable an option parameter. If not
   given, the UUID is printed out. If given, it is stored in the env
   variable.
 - corrected typos
 - return error codes

changes v1 -> v2:
 - fix return code of do_fs_uuid(..)
 - document do_fs_uuid(..)
 - implement fs_uuid_unsuported(..) be more consistent with the
   way other optional functionality works

changes v2 -> v3:
 - change ext4fs_uuid(..) to make use of #if .. #else .. #endif
   construct to get rid of unreachable code

Hit any key to stop autoboot:  0
=> fsuuid
fsuuid - Look up a filesystem UUID

Usage:
fsuuid <interface> <dev>:<part>
    - print filesystem UUID
fsuuid <interface> <dev>:<part> <varname>
    - set environment variable to filesystem UUID

=> fsuuid mmc 0:1
d9f9fc05-45ae-4a36-a616-fccce0e4f887
=> fsuuid mmc 0:2
eb3db83c-7b28-499f-95ce-9e0bb21cda81
=> fsuuid mmc 0:1 uuid1
=> fsuuid mmc 0:2 uuid2
=> printenv uuid1
uuid1=d9f9fc05-45ae-4a36-a616-fccce0e4f887
=> printenv uuid2
uuid2=eb3db83c-7b28-499f-95ce-9e0bb21cda81
=>

Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
2014-11-23 06:49:01 -05:00