ext4: fix ext4_end_io_dio() racing against fsync()

We need to make sure iocb->private is cleared *before* we put the
io_end structure on i_completed_io_list.  Otherwise fsync() could
potentially run on another CPU and free the iocb structure out from
under us.

Reported-by: Kent Overstreet <koverstreet@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org

commit b45c13576670e24a340c978aa470cb2e5994f937 1 parent 7ddb52a7e8
pinpong authored 8 hours ago
+ ext4: optimize ext4_ext_convert_to_initialized() -> https://github.com/DerTeufel/samsung-kernel-aries/commit/e9450b66b4400dd2ec3dec72f2d75401472f4b3b
+ ext4: optimize memmmove lengths in extent/index insertions -> https://github.com/DerTeufel/samsung-kernel-aries/commit/cdd09c6c71bb4519c5dfa1a04924d37e7a75cda5
+ NOATIME and NODIRATIME by default -> https://github.com/DerTeufel/samsung-kernel-aries/commit/6c0c048f39c64c932cbee050bc8ec7ac54a898cf
REALTIME by default changed to NOATIME! boost to battery save and I/O speed!
ext4: Speed up FITRIM by recording flags in ext4_group_info

In ext4, when FITRIM is called every time, we iterate all the
groups and do trim one by one. It is a bit time wasting if the
group has been trimmed and there is no change since the last
trim.

So this patch adds a new flag in ext4_group_info->bb_state to
indicate that the group has been trimmed, and it will be cleared
if some blocks is freed(in release_blocks_on_commit). Another
trim_minlen is added in ext4_sb_info to record the last minlen
we use to trim the volume, so that if the caller provide a small
one, we will go on the trim regardless of the bb_state.

A simple test with my intel x25m ssd:
df -h shows:
/dev/sdb1              40G   21G   17G  56% /mnt/ext4
Block size:               4096

run the FITRIM with the following parameter:
range.start = 0;
range.len = UINT64_MAX;
range.minlen = 1048576;

without the patch:
[root@boyu-tm linux-2.6]# time ./ftrim /mnt/ext4/a
real	0m5.505s
user	0m0.000s
sys	0m1.224s
[root@boyu-tm linux-2.6]# time ./ftrim /mnt/ext4/a
real	0m5.359s
user	0m0.000s
sys	0m1.178s
[root@boyu-tm linux-2.6]# time ./ftrim /mnt/ext4/a
real	0m5.228s
user	0m0.000s
sys	0m1.151s

with the patch:
[root@boyu-tm linux-2.6]# time ./ftrim /mnt/ext4/a
real	0m5.625s
user	0m0.000s
sys	0m1.269s
[root@boyu-tm linux-2.6]# time ./ftrim /mnt/ext4/a
real	0m0.002s
user	0m0.000s
sys	0m0.001s
[root@boyu-tm linux-2.6]# time ./ftrim /mnt/ext4/a
real	0m0.002s
user	0m0.000s
sys	0m0.001s

A big improvement for the 2nd and 3rd run.

Even after I delete some big image files, it is still much
faster than iterating the whole disk.

[root@boyu-tm test]# time ./ftrim /mnt/ext4/a
real	0m1.217s
user	0m0.000s
sys	0m0.196s

Cc: Lukas Czerner <lczerner@redhat.com>
Reviewed-by: Andreas Dilger <adilger.kernel@dilger.ca>
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
(cherry picked from commit 3d56b8d2c74cc3f375ce332b3ac3519e009d79ee)
ext4: ignore journalled data options on remount if fs has no journal

This avoids a confusing failure in the init scripts when the
/etc/fstab has data=writeback or data=journal but the file system does
not have a journal.  So check for this case explicitly, and warn the
user that we are ignoring the (pointless, since they have no journal)
data=* mount option.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
(cherry picked from commit eb513689c97e3e73bb9b4459d490a8e894b4a546)