linux-toradex.git/fs/ext4/extents.c, branch v4.16-rc3

ext4: fix up remaining files with SPDX cleanups

2017-12-18T03:00:59+00:00

A number of ext4 source files were skipped due because their copyright
permission statements didn't match the expected text used by the
automated conversion utilities.  I've added SPDX tags for the rest.

While looking at some of these files, I've noticed that we have quite
a bit of variation on the licenses that were used --- in particular
some of the Red Hat licenses on the jbd2 files use a GPL2+ license,
and we have some files that have a LGPL-2.1 license (which was quite
surprising).

I've not attempted to do any license changes.  Even if it is perfectly
legal to relicense to GPL 2.0-only for consistency's sake, that should
be done with ext4 developer community discussion.

Signed-off-by: Theodore Ts'o

ext4: fix fdatasync(2) after fallocate(2) operation

2017-12-04T03:52:51+00:00

Currently, fallocate(2) with KEEP_SIZE followed by a fdatasync(2)
then crash, we'll see wrong allocated block number (stat -c %b), the
blocks allocated beyond EOF are all lost. fstests generic/468
exposes this bug.

Commit 67a7d5f561f4 ("ext4: fix fdatasync(2) after extent
manipulation operations") fixed all the other extent manipulation
operation paths such as hole punch, zero range, collapse range etc.,
but forgot the fallocate case.

So similarly, fix it by recording the correct journal tid in ext4
inode in fallocate(2) path, so that ext4_sync_file() will wait for
the right tid to be committed on fdatasync(2).

This addresses the test failure in xfstests test generic/468.

Signed-off-by: Eryu Guan 
Signed-off-by: Theodore Ts'o 
Cc: stable@vger.kernel.org

ext4: fix interaction between i_size, fallocate, and delalloc after a crash

2017-10-07T03:09:55+00:00

If there are pending writes subject to delayed allocation, then i_size
will show size after the writes have completed, while i_disksize
contains the value of i_size on the disk (since the writes have not
been persisted to disk).

If fallocate(2) is called with the FALLOC_FL_KEEP_SIZE flag, either
with or without the FALLOC_FL_ZERO_RANGE flag set, and the new size
after the fallocate(2) is between i_size and i_disksize, then after a
crash, if a journal commit has resulted in the changes made by the
fallocate() call to be persisted after a crash, but the delayed
allocation write has not resolved itself, i_size would not be updated,
and this would cause the following e2fsck complaint:

Inode 12, end of extent exceeds allowed value
	(logical block 33, physical block 33441, len 7)

This can only take place on a sparse file, where the fallocate(2) call
is allocating blocks in a range which is before a pending delayed
allocation write which is extending i_size.  Since this situation is
quite rare, and the window in which the crash must take place is
typically < 30 seconds, in practice this condition will rarely happen.

Nevertheless, it can be triggered in testing, and in particular by
xfstests generic/456.

Signed-off-by: Theodore Ts'o 
Reported-by: Amir Goldstein 
Cc: stable@vger.kernel.org

ext4: fix copy paste error in ext4_swap_extents()

2017-08-06T05:33:07+00:00

This bug was found by a static code checker tool for copy paste
problems.

Signed-off-by: Maninder Singh 
Signed-off-by: Vaneet Narang 
Signed-off-by: Theodore Ts'o

ext4: remove unused mode parameter

2017-08-06T02:15:45+00:00

ext4_alloc_file_blocks() does not use its mode parameter. Remove it.

Signed-off-by: Tahsin Erdogan 
Signed-off-by: Theodore Ts'o

ext4: call journal revoke when freeing ea_inode blocks

2017-06-22T01:36:51+00:00

ea_inode contents are treated as metadata, that's why it is journaled
during initial writes. Failing to call revoke during freeing could cause
user data to be overwritten with original ea_inode contents during journal
replay.

Signed-off-by: Tahsin Erdogan 
Signed-off-by: Theodore Ts'o

ext4: fix fdatasync(2) after extent manipulation operations

2017-05-29T17:24:55+00:00

Currently, extent manipulation operations such as hole punch, range
zeroing, or extent shifting do not record the fact that file data has
changed and thus fdatasync(2) has a work to do. As a result if we crash
e.g. after a punch hole and fdatasync, user can still possibly see the
punched out data after journal replay. Test generic/392 fails due to
these problems.

Fix the problem by properly marking that file data has changed in these
operations.

CC: stable@vger.kernel.org
Fixes: a4bb6b64e39abc0e41ca077725f2a72c868e7622
Signed-off-by: Jan Kara 
Signed-off-by: Theodore Ts'o

ext4: fix data corruption with EXT4_GET_BLOCKS_ZERO

2017-05-26T21:40:52+00:00

When ext4_map_blocks() is called with EXT4_GET_BLOCKS_ZERO to zero-out
allocated blocks and these blocks are actually converted from unwritten
extent the following race can happen:

CPU0					CPU1

page fault				page fault
...					...
ext4_map_blocks()
  ext4_ext_map_blocks()
    ext4_ext_handle_unwritten_extents()
      ext4_ext_convert_to_initialized()
	- zero out converted extent
	ext4_zeroout_es()
	  - inserts extent as initialized in status tree

					ext4_map_blocks()
					  ext4_es_lookup_extent()
					    - finds initialized extent
					write data
  ext4_issue_zeroout()
    - zeroes out new extent overwriting data

This problem can be reproduced by generic/340 for the fallocated case
for the last block in the file.

Fix the problem by avoiding zeroing out the area we are mapping with
ext4_map_blocks() in ext4_ext_convert_to_initialized(). It is pointless
to zero out this area in the first place as the caller asked us to
convert the area to initialized because he is just going to write data
there before the transaction finishes. To achieve this we delete the
special case of zeroing out full extent as that will be handled by the
cases below zeroing only the part of the extent that needs it. We also
instruct ext4_split_extent() that the middle of extent being split
contains data so that ext4_split_extent_at() cannot zero out full extent
in case of ENOSPC.

CC: stable@vger.kernel.org
Fixes: 12735f881952c32b31bc4e433768f18489f79ec9
Signed-off-by: Jan Kara 
Signed-off-by: Theodore Ts'o

ext4: do not polute the extents cache while shifting extents

2017-01-09T02:00:35+00:00

Inside ext4_ext_shift_extents() function ext4_find_extent() is called
without EXT4_EX_NOCACHE flag, which should prevent cache population.

This leads to oudated offsets in the extents tree and wrong blocks
afterwards.

Patch fixes the problem providing EXT4_EX_NOCACHE flag for each
ext4_find_extents() call inside ext4_ext_shift_extents function.

Fixes: 331573febb6a2
Signed-off-by: Roman Pen 
Signed-off-by: Theodore Ts'o 
Cc: Namjae Jeon 
Cc: Andreas Dilger 
Cc: stable@vger.kernel.org

ext4: Include forgotten start block on fallocate insert range

2017-01-09T01:59:35+00:00

While doing 'insert range' start block should be also shifted right.
The bug can be easily reproduced by the following test:

    ptr = malloc(4096);
    assert(ptr);

    fd = open("./ext4.file", O_CREAT | O_TRUNC | O_RDWR, 0600);
    assert(fd >= 0);

    rc = fallocate(fd, 0, 0, 8192);
    assert(rc == 0);
    for (i = 0; i < 2048; i++)
            *((unsigned short *)ptr + i) = 0xbeef;
    rc = pwrite(fd, ptr, 4096, 0);
    assert(rc == 4096);
    rc = pwrite(fd, ptr, 4096, 4096);
    assert(rc == 4096);

    for (block = 2; block < 1000; block++) {
            rc = fallocate(fd, FALLOC_FL_INSERT_RANGE, 4096, 4096);
            assert(rc == 0);

            for (i = 0; i < 2048; i++)
                    *((unsigned short *)ptr + i) = block;

            rc = pwrite(fd, ptr, 4096, 4096);
            assert(rc == 4096);
    }

Because start block is not included in the range the hole appears at
the wrong offset (just after the desired offset) and the following
pwrite() overwrites already existent block, keeping hole untouched.

Simple way to verify wrong behaviour is to check zeroed blocks after
the test:

   $ hexdump ./ext4.file | grep '0000 0000'

The root cause of the bug is a wrong range (start, stop], where start
should be inclusive, i.e. [start, stop].

This patch fixes the problem by including start into the range.  But
not to break left shift (range collapse) stop points to the beginning
of the a block, not to the end.

The other not obvious change is an iterator check on validness in a
main loop.  Because iterator is unsigned the following corner case
should be considered with care: insert a block at 0 offset, when stop
variables overflows and never becomes less than start, which is 0.
To handle this special case iterator is set to NULL to indicate that
end of the loop is reached.

Fixes: 331573febb6a2
Signed-off-by: Roman Pen 
Signed-off-by: Theodore Ts'o 
Cc: Namjae Jeon 
Cc: Andreas Dilger 
Cc: stable@vger.kernel.org