linux-toradex.git/fs/ext4/inline.c, branch v3.18.4

ext4: Replace open coded mdata csum feature to helper function

2014-10-13T07:36:16+00:00

Besides the fact that this replacement improves code readability
it also protects from errors caused direct EXT4_S(sb)->s_es manipulation
which may result attempt to use uninitialized  csum machinery.

#Testcase_BEGIN
IMG=/dev/ram0
MNT=/mnt
mkfs.ext4 $IMG
mount $IMG $MNT
#Enable feature directly on disk, on mounted fs
tune2fs -O metadata_csum  $IMG
# Provoke metadata update, likey result in OOPS
touch $MNT/test
umount $MNT
#Testcase_END

# Replacement script
@@
expression E;
@@
- EXT4_HAS_RO_COMPAT_FEATURE(E, EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)
+ ext4_has_metadata_csum(E)

https://bugzilla.kernel.org/show_bug.cgi?id=82201

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

ext4: don't keep using page if inline conversion fails

2014-09-11T15:45:12+00:00

If inline->extent conversion fails (most probably due to ENOSPC) and
we release the temporary page that we allocated to transfer the file
contents, don't keep using the page pointer after releasing the page.
This occasionally leads to complaints about evicting locked pages or
hangs when blocksize > pagesize, because it's possible for the page to
get reallocated elsewhere in the meantime.

Signed-off-by: Darrick J. Wong 
Signed-off-by: Theodore Ts'o 
Reviewed-by: Jan Kara 
Cc: Tao Ma

ext4: check inline directory before converting

2014-07-28T17:06:26+00:00

Before converting an inline directory to a regular directory, check
the directory entries to make sure they're not obviously broken.
This helps us to avoid a BUG_ON if one of the dirents is trashed.

Signed-off-by: Darrick J. Wong 
Signed-off-by: Theodore Ts'o 
Reviewed-by: Andreas Dilger

ext4: make ext4_has_inline_data() as a inline function

2014-07-15T14:10:04+00:00

Now ext4_has_inline_data() is used in wide spread codepaths.  So we need
to make it as a inline function to avoid burning some CPU cycles.

Change in text size:

         text     data      bss     dec     hex filename
before: 326110    19258    5528  350896   55ab0 fs/ext4/ext4.o
after:  326227    19258    5528  351013   55b25 fs/ext4/ext4.o

I use the following script to measure the CPU usage.

  #!/bin/bash

  shm_base='/dev/shm'
  img=${shm_base}/ext4-img
  mnt=/mnt/loop

  e2fsprgs_base=$HOME/e2fsprogs
  mkfs=${e2fsprgs_base}/misc/mke2fs
  fsck=${e2fsprgs_base}/e2fsck/e2fsck

  sudo umount $mnt
  dd if=/dev/zero of=$img bs=4k count=3145728
  ${mkfs} -t ext4 -O inline_data -F $img
  sudo mount -t ext4 -o loop $img $mnt

  # start testing...
  testdir="${mnt}/testdir"
  mkdir $testdir
  cd $testdir

  echo "start testing..."
  for ((cnt=0;cnt<100;cnt++)); do

  for ((i=0;i<5;i++)); do
  	for ((j=0;j<5;j++)); do
  		for ((k=0;k<5;k++)); do
  			for ((l=0;l<5;l++)); do
  				mkdir -p $i/$j/$k/$l
  				echo "$i-$j-$k-$l" > $i/$j/$k/$l/testfile
  			done
  		done
  	done
  done

  ls -R $testdir > /dev/null
  rm -rf $testdir/*

  done

The result of `perf top -G -U` is as below.

vanilla:
 13.92%  [ext4]  [k] ext4_do_update_inode
  9.36%  [ext4]  [k] __ext4_get_inode_loc
  4.07%  [ext4]  [k] ftrace_define_fields_ext4_writepages
  3.83%  [ext4]  [k] __ext4_handle_dirty_metadata
  3.42%  [ext4]  [k] ext4_get_inode_flags
  2.71%  [ext4]  [k] ext4_mark_iloc_dirty
  2.46%  [ext4]  [k] ftrace_define_fields_ext4_direct_IO_enter
  2.26%  [ext4]  [k] ext4_get_inode_loc
  2.22%  [ext4]  [k] ext4_has_inline_data
  [...]

After applied the patch, we don't see ext4_has_inline_data() because it
has been inlined and perf couldn't sample it.  Although it doesn't mean
that the CPU cycles can be saved but at least the overhead of function
calls can be eliminated.  So IMHO we'd better inline this function.

Cc: Andreas Dilger 
Signed-off-by: Zheng Liu 
Signed-off-by: Theodore Ts'o

ext4: add missing BUFFER_TRACE before ext4_journal_get_write_access

2014-05-13T02:06:43+00:00

Make them more consistently

Signed-off-by: xieliang 
Signed-off-by: "Theodore Ts'o"

ext4: make local functions static

2014-05-12T14:50:23+00:00

I have been running make namespacecheck to look for unneeded globals, and
found these in ext4.

Signed-off-by: Stephen Hemminger 
Signed-off-by: "Theodore Ts'o"

ext4: delete "set but not used" variables

2014-01-11T18:26:56+00:00

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

ext4: avoid clearing beyond i_blocks when truncating an inline data file

2014-01-07T17:58:19+00:00

A missing cast means that when we are truncating a file which is less
than 60 bytes, we don't clear the correct area of memory, and in fact
we can end up truncating the next inode in the inode table, or worse
yet, some other kernel data structure.

Addresses-Coverity-Id: #751987

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

ext4: standardize error handling in ext4_da_write_inline_data_begin()

2014-01-06T19:03:23+00:00

The function has a bit non-standard (for ext4) error recovery in that it
used a mix of 'out' labels and testing for 'handle' being NULL. There
isn't a good reason for that in the function so clean it up a bit.

Signed-off-by: Jan Kara 
Signed-off-by: "Theodore Ts'o"

ext4: retry allocation when inline->extent conversion failed

2014-01-06T19:02:23+00:00

Similarly as other ->write_begin functions in ext4, also
ext4_da_write_inline_data_begin() should retry allocation if the
conversion failed because of ENOSPC. This avoids returning ENOSPC
prematurely because of uncommitted block deletions.

Signed-off-by: Jan Kara 
Signed-off-by: "Theodore Ts'o"