linux-toradex.git/fs/ext4/ext4_extents.h, branch v4.4.42

ext4: teach ext4_ext_find_extent() to realloc path if necessary

2014-09-01T18:40:09+00:00

This adds additional safety in case for some reason we end reusing a
path structure which isn't big enough for current depth of the inode.

Signed-off-by: Theodore Ts'o

ext4: rename uninitialized extents to unwritten

2014-04-21T03:45:47+00:00

Currently in ext4 there is quite a mess when it comes to naming
unwritten extents. Sometimes we call it uninitialized and sometimes we
refer to it as unwritten.

The right name for the extent which has been allocated but does not
contain any written data is _unwritten_. Other file systems are
using this name consistently, even the buffer head state refers to it as
unwritten. We need to fix this confusion in ext4.

This commit changes every reference to an uninitialized extent (meaning
allocated but unwritten) to unwritten extent. This includes comments,
function names and variable names. It even covers abbreviation of the
word uninitialized (such as uninit) and some misspellings.

This commit does not change any of the code paths at all. This has been
confirmed by comparing md5sums of the assembly code of each object file
after all the function names were stripped from it.

Signed-off-by: Lukas Czerner 
Signed-off-by: "Theodore Ts'o"

ext4: isolate ext4_extents.h file

2013-08-28T18:47:06+00:00

After applied the commit (4a092d73), we have reduced the number of
source files that need to #include ext4_extents.h.  But we can do
better.

This commit defines ext4_zeroout_es() in extents.c and move
EXT_MAX_BLOCKS into ext4.h in order not to include ext4_extents.h in
indirect.c and ioctl.c.  Meanwhile we just need to include this file in
extent_status.c when ES_AGGRESSIVE_TEST is defined.  Otherwise, this
commit removes a duplicated declaration in trace/events/ext4.h.

After applied this patch, we just need to include ext4_extents.h file
in {super,migrate,move_extents,extents}.c, and it is easy for us to
define a new extent disk layout.

Signed-off-by: Zheng Liu 
Signed-off-by: "Theodore Ts'o"

ext4: mext_insert_extents should update extent block checksum

2013-04-19T18:04:12+00:00

Signed-off-by: Darrick J. Wong 
Signed-off-by: "Theodore Ts'o"

ext4: remove single extent cache

2013-02-18T05:31:07+00:00

Single extent cache could be removed because we have extent status tree
as a extent cache, and it would be better.

Signed-off-by: Zheng Liu 
Signed-off-by: "Theodore Ts'o" 
Cc: Jan kara

ext4: rationalize ext4_extents.h inclusion

2012-11-28T18:03:30+00:00

Previously, ext4_extents.h was being included at the end of ext4.h,
which was bad for a number of reasons: (a) it was not being included
in the expected place, and (b) it caused the header to be included
multiple times.  There were #ifdef's to prevent this from causing any
problems, but it still was unnecessary.

By moving the function declarations that were in ext4_extents.h to
ext4.h, which is standard practice for where the function declarations
for the rest of ext4.h can be found, we can remove ext4_extents.h from
being included in ext4.h at all, and then we can only include
ext4_extents.h where it is needed in ext4's source files.

It should be possible to move a few more things into ext4.h, and
further reduce the number of source files that need to #include
ext4_extents.h, but that's a cleanup for another day.

Reported-by: Sachin Kamat 
Reported-by: Wei Yongjun 
Signed-off-by: "Theodore Ts'o"

ext4: prevent race while walking extent tree for fiemap

2012-11-28T17:32:26+00:00

Currently ext4_ext_walk_space() only takes i_data_sem for read when
searching for the extent at given block with ext4_ext_find_extent().
Then it drops the lock and the extent tree can be changed at will.
However later on we're searching for the 'next' extent, but the extent
tree might already have changed, so the information might not be
accurate.

In fact we can hit BUG_ON(end <= start) if the extent got inserted into
the tree after the one we found and before the block we were searching
for. This has been reproduced by running xfstests 225 in loop on s390x
architecture, but theoretically we could hit this on any other
architecture as well, but probably not as often.

Moreover the extent currently in delayed allocation might be allocated
after we search the extent tree and before we search extent status tree
delayed buffers resulting in those delayed buffers being completely
missed, even though completely written and allocated.

We fix all those problems in several steps:

 1. remove unnecessary callback indirection
 2. rename functions
        ext4_ext_walk_space -> ext4_fill_fiemap_extents
        ext4_ext_fiemap_cb -> ext4_find_delayed_extent
 3. move fiemap_fill_next_extent() into ext4_fill_fiemap_extents()
 4. hold the i_data_sem for:
        ext4_ext_find_extent()
        ext4_ext_next_allocated_block()
        ext4_find_delayed_extent()
 5. call fiemap_fill_next_extent after releasing the i_data_sem
 6. move path reinitialization into the critical section.

Signed-off-by: Lukas Czerner 
Signed-off-by: "Theodore Ts'o"

ext4: reimplement ext4_find_delay_alloc_range on extent status tree

2012-11-09T02:57:35+00:00

Signed-off-by: Yongqiang Yang 
Signed-off-by: Allison Henderson 
Signed-off-by: Zheng Liu 
Signed-off-by: "Theodore Ts'o"

ext4: verify and calculate checksums for extent tree blocks

2012-04-29T22:37:10+00:00

Calculate and verify the checksum for each extent tree block.  The
checksum is located in the space immediately after the last possible
ext4_extent in the block.  The space is is typically the last 4-8
bytes in the block.

Signed-off-by: Darrick J. Wong 
Signed-off-by: "Theodore Ts'o"

ext4: change on-disk layout to support extended metadata checksumming

2012-04-29T22:23:10+00:00

Define flags and change structure definitions to allow checksumming of
ext4 metadata.

Signed-off-by: Darrick J. Wong 
Signed-off-by: "Theodore Ts'o"