u-boot.git/fs/ext4/ext4_write.c, branch v2017.03

ext4: Respect group descriptor size when adjusting free counts

2016-09-23T13:20:16+00:00

Also adjust high 16/32 bits when free inode/block counts are modified.

Signed-off-by: Stefan Brüns

ext4: Use helper function to access group descriptor and its fields

2016-09-23T13:20:15+00:00

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

ext4: Correct block number handling, empty block vs. error code

2016-09-23T13:02:44+00:00

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

ext4: remove duplicated block release code for extents

2016-09-23T13:02:43+00:00

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

ext4: initialize full inode for inodes bigger than 128 bytes

2016-09-23T13:02:42+00:00

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 
Reviewed-by: Lukasz Majewski

ext4: Use correct value for inode size even on revision 0 filesystems

2016-09-23T13:02:42+00:00

fs->inodesz is already correctly (i.e. dependent on fs revision)
initialized in ext4fs_mount.

Signed-off-by: Stefan Brüns 
Reviewed-by: Lukasz Majewski

ext4: Fix memory leak in case of failure

2016-09-23T13:02:41+00:00

temp_ptr should always be freed, even if the function is left via
goto fail.

Signed-off-by: Stefan Brüns 
Reviewed-by: Lukasz Majewski

ext4: Avoid corruption of directories with hash tree indexes

2016-09-23T13:02:37+00:00

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 
Reviewed-by: Lukasz Majewski

ext4: propagate error if creation of directory entry fails

2016-09-23T13:02:35+00:00

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 
Reviewed-by: Lukasz Majewski

ext4: fix possible crash on directory traversal, ignore deleted entries

2016-09-23T13:02:34+00:00

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 
Reviewed-by: Lukasz Majewski