linux-stable.git/fs/ext4, branch v4.4.54

ext4: return EROFS if device is r/o and journal replay is needed

2017-03-12T05:37:27+00:00

commit 4753d8a24d4588657bc0a4cd66d4e282dff15c8c upstream.

If the file system requires journal recovery, and the device is
read-ony, return EROFS to the mount system call.  This allows xfstests
generic/050 to pass.

Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

ext4: preserve the needs_recovery flag when the journal is aborted

2017-03-12T05:37:27+00:00

commit 97abd7d4b5d9c48ec15c425485f054e1c15e591b upstream.

If the journal is aborted, the needs_recovery feature flag should not
be removed.  Otherwise, it's the journal might not get replayed and
this could lead to more data getting lost.

Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

ext4: fix inline data error paths

2017-03-12T05:37:27+00:00

commit eb5efbcb762aee4b454b04f7115f73ccbcf8f0ef upstream.

The write_end() function must always unlock the page and drop its ref
count, even on an error.

Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

ext4: fix data corruption in data=journal mode

2017-03-12T05:37:27+00:00

commit 3b136499e906460919f0d21a49db1aaccf0ae963 upstream.

ext4_journalled_write_end() did not propely handle all the cases when
generic_perform_write() did not copy all the data into the target page
and could mark buffers with uninitialized contents as uptodate and dirty
leading to possible data corruption (which would be quickly fixed by
generic_perform_write() retrying the write but still). Fix the problem
by carefully handling the case when the page that is written to is not
uptodate.

Reported-by: Al Viro 
Signed-off-by: Jan Kara 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

ext4: trim allocation requests to group size

2017-03-12T05:37:27+00:00

commit cd648b8a8fd5071d232242d5ee7ee3c0815776af upstream.

If filesystem groups are artifically small (using parameter -g to
mkfs.ext4), ext4_mb_normalize_request() can result in a request that is
larger than a block group. Trim the request size to not confuse
allocation code.

Reported-by: "Kirill A. Shutemov" 
Signed-off-by: Jan Kara 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

ext4: do not polute the extents cache while shifting extents

2017-03-12T05:37:27+00:00

commit 03e916fa8b5577d85471452a3d0c5738aa658dae upstream.

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 
Signed-off-by: Greg Kroah-Hartman

ext4: Include forgotten start block on fallocate insert range

2017-03-12T05:37:27+00:00

commit 2a9b8cba62c0741109c33a2be700ff3d7703a7c2 upstream.

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 
Signed-off-by: Greg Kroah-Hartman

ext4: validate s_first_meta_bg at mount time

2017-02-09T07:02:44+00:00

commit 3a4b77cd47bb837b8557595ec7425f281f2ca1fe upstream.

Ralf Spenneberg reported that he hit a kernel crash when mounting a
modified ext4 image. And it turns out that kernel crashed when
calculating fs overhead (ext4_calculate_overhead()), this is because
the image has very large s_first_meta_bg (debug code shows it's
842150400), and ext4 overruns the memory in count_overhead() when
setting bitmap buffer, which is PAGE_SIZE.

ext4_calculate_overhead():
  buf = get_zeroed_page(GFP_NOFS);  <=== PAGE_SIZE buffer
  blks = count_overhead(sb, i, buf);

count_overhead():
  for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) { <=== j = 842150400
          ext4_set_bit(EXT4_B2C(sbi, s++), buf);   <=== buffer overrun
          count++;
  }

This can be reproduced easily for me by this script:

  #!/bin/bash
  rm -f fs.img
  mkdir -p /mnt/ext4
  fallocate -l 16M fs.img
  mke2fs -t ext4 -O bigalloc,meta_bg,^resize_inode -F fs.img
  debugfs -w -R "ssv first_meta_bg 842150400" fs.img
  mount -o loop fs.img /mnt/ext4

Fix it by validating s_first_meta_bg first at mount time, and
refusing to mount if its value exceeds the largest possible meta_bg
number.

Reported-by: Ralf Spenneberg 
Signed-off-by: Eryu Guan 
Signed-off-by: Theodore Ts'o 
Reviewed-by: Andreas Dilger 
Signed-off-by: Greg Kroah-Hartman

ext4: do not perform data journaling when data is encrypted

2017-01-06T10:16:13+00:00

commit 73b92a2a5e97d17cc4d5c4fe9d724d3273fb6fd2 upstream.

Currently data journalling is incompatible with encryption: enabling both
at the same time has never been supported by design, and would result in
unpredictable behavior. However, users are not precluded from turning on
both features simultaneously. This change programmatically replaces data
journaling for encrypted regular files with ordered data journaling mode.

Background:
Journaling encrypted data has not been supported because it operates on
buffer heads of the page in the page cache. Namely, when the commit
happens, which could be up to five seconds after caching, the commit
thread uses the buffer heads attached to the page to copy the contents of
the page to the journal. With encryption, it would have been required to
keep the bounce buffer with ciphertext for up to the aforementioned five
seconds, since the page cache can only hold plaintext and could not be
used for journaling. Alternatively, it would be required to setup the
journal to initiate a callback at the commit time to perform deferred
encryption - in this case, not only would the data have to be written
twice, but it would also have to be encrypted twice. This level of
complexity was not justified for a mode that in practice is very rarely
used because of the overhead from the data journalling.

Solution:
If data=journaled has been set as a mount option for a filesystem, or if
journaling is enabled on a regular file, do not perform journaling if the
file is also encrypted, instead fall back to the data=ordered mode for the
file.

Rationale:
The intent is to allow seamless and proper filesystem operation when
journaling and encryption have both been enabled, and have these two
conflicting features gracefully resolved by the filesystem.

Fixes: 4461471107b7
Signed-off-by: Sergey Karamov 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

ext4: return -ENOMEM instead of success

2017-01-06T10:16:13+00:00

commit 578620f451f836389424833f1454eeeb2ffc9e9f upstream.

We should set the error code if kzalloc() fails.

Fixes: 67cf5b09a46f ("ext4: add the basic function for inline data support")
Signed-off-by: Dan Carpenter 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman