Reduce the object size ~10% could be useful for embedded systems.

Add #ifdef CONFIG_PRINTK #else #endif blocks to hold formats and
arguments, passing " " to functions when !CONFIG_PRINTK and still
verifying format and arguments with no_printk.

$ size fs/ext4/built-in.o*
   text	   data	    bss	    dec	    hex	filename
 239375	    610	    888	 240873	  3ace9	fs/ext4/built-in.o.new
 264167	    738	    888	 265793	  40e41	fs/ext4/built-in.o.old

    $ grep -E "CONFIG_EXT4|CONFIG_PRINTK" .config
    # CONFIG_PRINTK is not set
    CONFIG_EXT4_FS=y
    CONFIG_EXT4_USE_FOR_EXT23=y
    CONFIG_EXT4_FS_POSIX_ACL=y
    # CONFIG_EXT4_FS_SECURITY is not set
    # CONFIG_EXT4_DEBUG is not set
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Now we maintain an proper in-order LRU list in ext4 to reclaim entries
from extent status tree when we are under heavy memory pressure.  For
keeping this order, a spin lock is used to protect this list.  But this
lock burns a lot of CPU time.  We can use the following steps to trigger
it.

  % cd /dev/shm
  % dd if=/dev/zero of=ext4-img bs=1M count=2k
  % mkfs.ext4 ext4-img
  % mount -t ext4 -o loop ext4-img /mnt
  % cd /mnt
  % for ((i=0;i<160;i++)); do truncate -s 64g $i; done
  % for ((i=0;i<160;i++)); do cp $i /dev/null &; done
  % perf record -a -g
  % perf report

This commit tries to fix this problem.  Now a new member called
i_touch_when is added into ext4_inode_info to record the last access
time for an inode.  Meanwhile we never need to keep a proper in-order
LRU list.  So this can avoid to burns some CPU time.  When we try to
reclaim some entries from extent status tree, we use list_sort() to get
a proper in-order list.  Then we traverse this list to discard some
entries.  In ext4_sb_info, we use s_es_last_sorted to record the last
time of sorting this list.  When we traverse the list, we skip the inode
that is newer than this time, and move this inode to the tail of LRU
list.  When the head of the list is newer than s_es_last_sorted, we will
sort the LRU list again.

In this commit, we break the loop if s_extent_cache_cnt == 0 because
that means that all extents in extent status tree have been reclaimed.

Meanwhile in this commit, ext4_es_{un}register_shrinker()'s prototype is
changed to save a local variable in these functions.
Reported-by: NDave Hansen <dave.hansen@intel.com>
Signed-off-by: NZheng Liu <wenqing.lz@taobao.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

This patch removed several unused variables.
Signed-off-by: NJon Ernst <jonernst07@gmx.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

If filesystem was aborted after inode's write back is complete
but before its metadata was updated we may return success
results in data loss.
In order to handle fs abort correctly we have to check
fs state once we discover that it is in MS_RDONLY state

Test case: http://patchwork.ozlabs.org/patch/244297Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: NDmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Inode's data or non journaled quota may be written w/o jounral so we
_must_ send a barrier at the end of ext4_sync_fs. But it can be
skipped if journal commit will do it for us.

Also fix data integrity for nojournal mode.
Signed-off-by: NDmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Now that we have extent conversions with reserved transaction, we have
to prevent extent conversions without reserved transaction (from DIO
code) to block these (as that would effectively void any transaction
reservation we did).  So split lists, work items, and work queues to
reserved and unreserved parts.
Reviewed-by: NZheng Liu <wenqing.lz@taobao.com>
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

This attribute is now unused so deprecate it.  We still show the old
default value to keep some compatibility but we don't allow writing to
that attribute anymore.
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Suppress the messages releating to processing the ext4 orphan list
("truncating inode" and "deleting unreferenced inode") unless the
debug option is on, since otherwise they end up taking up space in the
log that could be used for more useful information.

Tested by opening several files, unlinking them, then
crashing the system, rebooting the system and examining
/var/log/messages.

Addresses the problem described in http://crbug.com/220976Signed-off-by: NPaul Taysom <taysom@chromium.org>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Currently we do not tell mm to zero out tail of the page before truncate
in orphan_cleanup(). This is ok, because the page should not be
uptodate, however this may eventually change and I might cause problems.

Call truncate_inode_pages() as precautionary measure. Thanks Jan Kara
for pointing this out.
Signed-off-by: NLukas Czerner <lczerner@redhat.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

same story as with the previous patches - note that return
value of blkdev_close() is lost, since there's nowhere the
caller (__fput()) could return it to.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

As Dave Chinner pointed out at the 2013 LSF/MM workshop, it's
important that metadata I/O requests are marked as such to avoid
priority inversions caused by I/O bandwidth throttling.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

In parse_strtoul() we're still using deprecated simple_strtoul().  Remove
parse_strtoul() altogether and replace it with kstrtoul()
Signed-off-by: NLukas Czerner <lczerner@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

None of these result in any bug, but they makes sparse complain.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Currently in ENOSPC condition when writing into unwritten space, or
punching a hole, we might need to split the extent and grow extent tree.
However since we can not allocate any new metadata blocks we'll have to
zero out unwritten part of extent or punched out part of extent, or in
the worst case return ENOSPC even though use actually does not allocate
any space.

Also in delalloc path we do reserve metadata and data blocks for the
time we're going to write out, however metadata block reservation is
very tricky especially since we expect that logical connectivity implies
physical connectivity, however that might not be the case and hence we
might end up allocating more metadata blocks than previously reserved.
So in future, metadata reservation checks should be removed since we can
not assure that we do not under reserve.

And this is where reserved space comes into the picture. When mounting
the file system we slice off a little bit of the file system space (2%
or 4096 clusters, whichever is smaller) which can be then used for the
cases mentioned above to prevent costly zeroout, or unexpected ENOSPC.

The number of reserved clusters can be set via sysfs, however it can
never be bigger than number of free clusters in the file system.

Note that this patch fixes the failure of xfstest 274 as expected.
Signed-off-by: NLukas Czerner <lczerner@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: NCarlos Maiolino <cmaiolino@redhat.com>

The only part of proc_dir_entry the code outside of fs/proc
really cares about is PDE(inode)->data.  Provide a helper
for that; static inline for now, eventually will be moved
to fs/proc, along with the knowledge of struct proc_dir_entry
layout.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

We didn't mark hidden quota files with S_NOQUOTA flag and thus quota was
accounted even for quota files. Thus we could recurse back to quota code
when adding new blocks to quota file which can easily deadlock. Mark
hidden quota files properly.
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Currently in when getting the block group number for a particular
block in ext4_block_in_group() we're using
ext4_get_group_no_and_offset() which uses do_div() to get the block
group and the remainer which is offset within the group.

We don't need all of that in ext4_block_in_group() as we only need to
figure out the group number.

This commit changes ext4_block_in_group() to calculate group number
directly. This shows as a big improvement with regards to cpu
utilization. Measuring fallocate -l 15T on fresh file system with perf
showed that 23% of cpu time was spend in the
ext4_get_group_no_and_offset(). With this change it completely
disappears from the list only bumping the occurrence of
ext4_init_block_bitmap() which is the biggest user of
ext4_block_in_group() by 4%. As the result of this change on my system
the fallocate call was approx. 10% faster.

However since there is '-g' option in mkfs which allow us setting
different groups size (mostly for developers) I've introduced new per
file system flag whether we have a standard block group size or
not. The flag is used to determine whether we can use the bit shift
optimization or not.
Signed-off-by: NLukas Czerner <lczerner@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Otherwise destroyed ext_sb_info will be part of global shinker list
and result in the following OOPS:

JBD2: corrupted journal superblock
JBD2: recovery failed
EXT4-fs (dm-2): error loading journal
general protection fault: 0000 [#1] SMP
Modules linked in: fuse acpi_cpufreq freq_table mperf coretemp kvm_intel kvm crc32c_intel microcode sg button sd_mod crc_t10dif ahci libahci pata_acpi ata_generic dm_mirror dm_region_hash dm_log dm_\
mod
CPU 1
Pid: 2758, comm: mount Not tainted 3.8.0-rc3+ #136                  /DH55TC
RIP: 0010:[<ffffffff811bfb2d>]  [<ffffffff811bfb2d>] unregister_shrinker+0xad/0xe0
RSP: 0000:ffff88011d5cbcd8  EFLAGS: 00010207
RAX: 6b6b6b6b6b6b6b6b RBX: 6b6b6b6b6b6b6b53 RCX: 0000000000000006
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000246
RBP: ffff88011d5cbce8 R08: 0000000000000002 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000000 R12: ffff88011cd3f848
R13: ffff88011cd3f830 R14: ffff88011cd3f000 R15: 0000000000000000
FS:  00007f7b721dd7e0(0000) GS:ffff880121a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 00007fffa6f75038 CR3: 000000011bc1c000 CR4: 00000000000007e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process mount (pid: 2758, threadinfo ffff88011d5ca000, task ffff880116aacb80)
Stack:
ffff88011cd3f000 ffffffff8209b6c0 ffff88011d5cbd18 ffffffff812482f1
00000000000003f3 00000000ffffffea ffff880115f4c200 0000000000000000
ffff88011d5cbda8 ffffffff81249381 ffff8801219d8bf8 ffffffff00000000
Call Trace:
[<ffffffff812482f1>] deactivate_locked_super+0x91/0xb0
[<ffffffff81249381>] mount_bdev+0x331/0x340
[<ffffffff81376730>] ? ext4_alloc_flex_bg_array+0x180/0x180
[<ffffffff81362035>] ext4_mount+0x15/0x20
[<ffffffff8124869a>] mount_fs+0x9a/0x2e0
[<ffffffff81277e25>] vfs_kern_mount+0xc5/0x170
[<ffffffff81279c02>] do_new_mount+0x172/0x2e0
[<ffffffff8127aa56>] do_mount+0x376/0x380
[<ffffffff8127ab98>] sys_mount+0x138/0x150
[<ffffffff818ffed9>] system_call_fastpath+0x16/0x1b
Code: 8b 05 88 04 eb 00 48 3d 90 ff 06 82 48 8d 58 e8 75 19 4c 89 e7 e8 e4 d7 2c 00 48 c7 c7 00 ff 06 82 e8 58 5f ef ff 5b 41 5c c9 c3 <48> 8b 4b 18 48 8b 73 20 48 89 da 31 c0 48 c7 c7 c5 a0 e4 81 e\
8
RIP  [<ffffffff811bfb2d>] unregister_shrinker+0xad/0xe0
RSP <ffff88011d5cbcd8>
Signed-off-by: NDmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org

It is incorrect to use list_for_each_entry_safe() for journal callback
traversial because ->next may be removed by other task:
->ext4_mb_free_metadata()
  ->ext4_mb_free_metadata()
    ->ext4_journal_callback_del()

This results in the following issue:

WARNING: at lib/list_debug.c:62 __list_del_entry+0x1c0/0x250()
Hardware name:
list_del corruption. prev->next should be ffff88019a4ec198, but was 6b6b6b6b6b6b6b6b
Modules linked in: cpufreq_ondemand acpi_cpufreq freq_table mperf coretemp kvm_intel kvm crc32c_intel ghash_clmulni_intel microcode sg xhci_hcd button sd_mod crc_t10dif aesni_intel ablk_helper cryptd lrw aes_x86_64 xts gf128mul ahci libahci pata_acpi ata_generic dm_mirror dm_region_hash dm_log dm_mod
Pid: 16400, comm: jbd2/dm-1-8 Tainted: G        W    3.8.0-rc3+ #107
Call Trace:
 [<ffffffff8106fb0d>] warn_slowpath_common+0xad/0xf0
 [<ffffffff8106fc06>] warn_slowpath_fmt+0x46/0x50
 [<ffffffff813637e9>] ? ext4_journal_commit_callback+0x99/0xc0
 [<ffffffff8148cae0>] __list_del_entry+0x1c0/0x250
 [<ffffffff813637bf>] ext4_journal_commit_callback+0x6f/0xc0
 [<ffffffff813ca336>] jbd2_journal_commit_transaction+0x23a6/0x2570
 [<ffffffff8108aa42>] ? try_to_del_timer_sync+0x82/0xa0
 [<ffffffff8108b491>] ? del_timer_sync+0x91/0x1e0
 [<ffffffff813d3ecf>] kjournald2+0x19f/0x6a0
 [<ffffffff810ad630>] ? wake_up_bit+0x40/0x40
 [<ffffffff813d3d30>] ? bit_spin_lock+0x80/0x80
 [<ffffffff810ac6be>] kthread+0x10e/0x120
 [<ffffffff810ac5b0>] ? __init_kthread_worker+0x70/0x70
 [<ffffffff818ff6ac>] ret_from_fork+0x7c/0xb0
 [<ffffffff810ac5b0>] ? __init_kthread_worker+0x70/0x70

This patch fix the issue as follows:
- ext4_journal_commit_callback() make list truly traversial safe
  simply by always starting from list_head
- fix race between two ext4_journal_callback_del() and
  ext4_journal_callback_try_del()
Signed-off-by: NDmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: stable@vger.kernel.com

I had assumed that the only use of module aliases for filesystems
prior to "fs: Limit sys_mount to only request filesystem modules."
was in request_module.  It turns out I was wrong.  At least mkinitcpio
in Arch linux uses these aliases.

So readd the preexising aliases, to keep from breaking userspace.

Userspace eventually will have to follow and use the same aliases the
kernel does.  So at some point we may be delete these aliases without
problems.  However that day is not today.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

A user who was using a 8TB+ file system and with a very large flexbg
size (> 65536) could cause the atomic_t used in the struct flex_groups
to overflow.  This was detected by PaX security patchset:

http://forums.grsecurity.net/viewtopic.php?f=3&t=3289&p=12551#p12551

This bug was introduced in commit 9f24e420, so it's been around
since 2.6.30.  :-(

Fix this by using an atomic64_t for struct orlav_stats's
free_clusters.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: NLukas Czerner <lczerner@redhat.com>
Cc: stable@vger.kernel.org

Modify the request_module to prefix the file system type with "fs-"
and add aliases to all of the filesystems that can be built as modules
to match.

A common practice is to build all of the kernel code and leave code
that is not commonly needed as modules, with the result that many
users are exposed to any bug anywhere in the kernel.

Looking for filesystems with a fs- prefix limits the pool of possible
modules that can be loaded by mount to just filesystems trivially
making things safer with no real cost.

Using aliases means user space can control the policy of which
filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf
with blacklist and alias directives.  Allowing simple, safe,
well understood work-arounds to known problematic software.

This also addresses a rare but unfortunate problem where the filesystem
name is not the same as it's module name and module auto-loading
would not work.  While writing this patch I saw a handful of such
cases.  The most significant being autofs that lives in the module
autofs4.

This is relevant to user namespaces because we can reach the request
module in get_fs_type() without having any special permissions, and
people get uncomfortable when a user specified string (in this case
the filesystem type) goes all of the way to request_module.

After having looked at this issue I don't think there is any
particular reason to perform any filtering or permission checks beyond
making it clear in the module request that we want a filesystem
module.  The common pattern in the kernel is to call request_module()
without regards to the users permissions.  In general all a filesystem
module does once loaded is call register_filesystem() and go to sleep.
Which means there is not much attack surface exposed by loading a
filesytem module unless the filesystem is mounted.  In a user
namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT,
which most filesystems do not set today.
Acked-by: NSerge Hallyn <serge.hallyn@canonical.com>
Acked-by: NKees Cook <keescook@chromium.org>
Reported-by: NKees Cook <keescook@google.com>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

When using quota feature we need to enable quotas before orphan cleanup
so that changes happening during it are properly reflected in quota
accounting.
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

So far we silently ignored when quota mount options were set while quota
feature was enabled.  But this can create confusion in userspace when
mount options are set but silently ignored and also creates opportunities
for bugs when we don't properly test all quota types.  Actually
ext4_mark_dquot_dirty() forgets to test for quota feature so it was
dependent on journaled quota options being set.  OTOH ext4_orphan_cleanup()
tries to enable journaled quota when quota options are specified which is
wrong when quota feature is enabled.
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

We're using macro EXT4_B2C() to convert number of blocks to number of
clusters for bigalloc file systems.  However, we should be using
EXT4_NUM_B2C().
Signed-off-by: NLukas Czerner <lczerner@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org

'orig_data' is malloced in ext4_remount() and should be freed
before leaving from the error handling cases, otherwise it will
cause memory leak.
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: NLukas Czerner <lczerner@redhat.com>
Cc: stable@vger.kernel.org

Use a percpu counter rather than atomic types for shrinker accounting.
There's no need for ultimate accuracy in the shrinker, so this
should come a little more cheaply.  The percpu struct is somewhat
large, but there was a big gap before the cache-aligned
s_es_lru_lock anyway, and it fits nicely in there.
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Although extent status is loaded on-demand, we also need to reclaim
extent from the tree when we are under a heavy memory pressure because
in some cases fragmented extent tree causes status tree costs too much
memory.

Here we maintain a lru list in super_block.  When the extent status of
an inode is accessed and changed, this inode will be move to the tail
of the list.  The inode will be dropped from this list when it is
cleared.  In the inode, a counter is added to count the number of
cached objects in extent status tree.  Here only written/unwritten/hole
extent is counted because delayed extent doesn't be reclaimed due to
fiemap, bigalloc and seek_data/hole need it.  The counter will be
increased as a new extent is allocated, and it will be decreased as a
extent is freed.

In this commit we use normal shrinker framework to reclaim memory from
the status tree.  ext4_es_reclaim_extents_count() traverses the lru list
to count the number of reclaimable extents.  ext4_es_shrink() tries to
reclaim written/unwritten/hole extents from extent status tree.  The
inode that has been shrunk is moved to the tail of lru list.
Signed-off-by: NZheng Liu <wenqing.lz@taobao.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: Jan kara <jack@suse.cz>

Single extent cache could be removed because we have extent status tree
as a extent cache, and it would be better.
Signed-off-by: NZheng Liu <wenqing.lz@taobao.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: Jan kara <jack@suse.cz>

So we can better understand what bits of ext4 are responsible for
long-running jbd2 handles, use jbd2__journal_start() so we can pass
context information for logging purposes.

The recommended way for finding the longer-running handles is:

   T=/sys/kernel/debug/tracing
   EVENT=$T/events/jbd2/jbd2_handle_stats
   echo "interval > 5" > $EVENT/filter
   echo 1 > $EVENT/enable

   ./run-my-fs-benchmark

   cat $T/trace > /tmp/problem-handles

This will list handles that were active for longer than 20ms.  Having
longer-running handles is bad, because a commit started at the wrong
time could stall for those 20+ milliseconds, which could delay an
fsync() or an O_SYNC operation.  Here is an example line from the
trace file describing a handle which lived on for 311 jiffies, or over
1.2 seconds:

postmark-2917  [000] ....   196.435786: jbd2_handle_stats: dev 254,32 
   tid 570 type 2 line_no 2541 interval 311 sync 0 requested_blocks 1
   dirtied_blocks 0
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Move the jbd2 wrapper functions which start and stop handles out of
super.c, where they don't really logically belong, and into
ext4_jbd2.c.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Check for incompatible mount options when using the ext4 file system
driver to mount ext2 or ext3 file systems.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

If argument of inode_readahead_blk is too big, we just bail out
without printing any error. Fix this since it could confuse users.
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

The loop looking for correct mount option entry is more logical if it is
written rewritten as an empty loop looking for correct option entry and then
code handling the option. It also saves one level of indentation for a lot of
code so we can join a couple of split lines.
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Several mount option (resuid, resgid, journal_dev, journal_ioprio) are
currently handled before we enter standard option handling loop. I don't
see a reason for this so move them to normal handling loop to make things
more regular.
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

brelse() and ext4_journal_force_commit() are both inlined and able
to handle NULL.
Signed-off-by: NGuo Chao <yan@linux.vnet.ibm.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

It does not make much sense to have struct work in ext4_io_end_t
because we always use it for only one ext4_io_end_t per inode (the
first one in the i_completed_io list). So just move the structure to
inode itself.  This also allows for a small simplification in
processing io_end structures.
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Currently we sometimes used block_write_full_page() and sometimes
ext4_bio_write_page() for writeback (depending on mount options and call
path). Let's always use ext4_bio_write_page() to simplify things a bit.
Reviewed-by: NZheng Liu <wenqing.lz@taobao.com>
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

When usrjquota or grpjquota mount options are specified several times,
we leak memory storing the names. Free the memory correctly.
Signed-off-by: NChen Gang <gang.chen@asianux.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: NJan Kara <jack@suse.cz>