Cgroup writeback requires explicit support from the filesystem.
f2fs's data and node writeback IOs go through __write_data_page,
which sets fio for submiting IOs. So, we add io_wbc for fio,
associate bios with blkcg by invoking wbc_init_bio() and
account IOs issuing by wbc_account_io().
In addtion, f2fs_fill_super() is updated to set SB_I_CGROUPWB.

Meta writeback IOs is left alone by this patch and will always be
attributed to the root cgroup.

The results show that f2fs can throttle writeback nicely for
data writing and file creating.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NYufen Yu <yuyufen@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In commit 78997b56 ("f2fs: split discard policy"), we have get rid
of using pend_list_tag field in struct discard_cmd_control, but forgot
to remove it, now do it.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

We take very long time to finish generic/476, this is because we will
check consistence of all discard entries in global rb tree while
traversing all different granularity pending lists, even when the list
is empty, in order to avoid that unneeded overhead, we have to skip
the check when coming up an empty list.

generic/476 time consumption:
					cost
Before patch & w/o consistence check	57s
Before patch & w/ consistence check	1426s
After patch				78s
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Fixes the following sparse warnings:

fs/f2fs/segment.c:887:6: warning:
 symbol '__check_sit_bitmap' was not declared. Should it be static?
fs/f2fs/segment.c:1327:6: warning:
 symbol 'f2fs_wait_discard_bio' was not declared. Should it be static?
fs/f2fs/super.c:1661:5: warning:
 symbol 'f2fs_get_projid' was not declared. Should it be static?
Signed-off-by: NWei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch allows root to reserve some blocks via mount option.

"-o reserve_root=N" means N x 4KB-sized blocks for root only.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In some case, the node blocks has wrong blkaddr whose segment type is
NODE, e.g., recover inode has missing xattr flag and the blkaddr is in
the xattr range. Since fsck.f2fs does not check the recovery nodes, this
will cause __f2fs_replace_block change the curseg of node and do the
update_sit_entry(sbi, new_blkaddr, 1) with no next_blkoff refresh, as a
result, when recovery process write checkpoint and sync nodes, the
next_blkoff of curseg is used in the segment bit map, then it will
cause f2fs_bug_on. So let's check segment type in __f2fs_replace_block.
Signed-off-by: NYunlong Song <yunlong.song@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

After checkpoint,
 1. creat a new file A ,(with dirty inode && dirty inode page && xattr info)
 2. backgroud wb write back file A inode page (without update from inode cache)
 3. fsync file A, write back inode page of file A with inode cache info
 4. sudden power off before new checkpoint

In this case, recovery process will try to recover a zero inode
page. Inline xattr flag of file A will be miss and xattr info
will be taken as blkaddr index.
Signed-off-by: NYunlei He <heyunlei@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Let's show precise # of blocks that user/root can use through bavail and bfree
respectively.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Commit 6afc662e ("f2fs: support flexible inline xattr size")
declared f2fs_sb_has_flexible_inline_xattr in f2fs.h for latter being
used in get_inline_xattr_addrs, but in latter version, related code
has been changed, leave f2fs_sb_has_flexible_inline_xattr w/o any
users. Let's remove it for cleanup.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

While doing direct IO, if we run out-of-space when we preallocate blocks,
we should not return ENOSPC error directly, instead, we should continue
to do following direct IO, which will keep directIO of f2fs acting like
other filesystems.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

We have to enable quota only when remounting from read to write. Otherwise,
we'll get remount failure. (e.g., write to write case)
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

We can give another chance to write user data, which can resolve
generic/441.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This fixes generic/449 hang problem caused by no ENOSPC forever which should be
returned by setxattr under disk full scenario.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This fixes generic/342 which doesn't recover renamed file which was fsynced
before. It will be done via another fsync on newly created file.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Let's avoid BUG_ON during fill_super, when on-disk was totall corrupted.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

-Thread A                             Thread B

-write_checkpoint
 -block_operations
  -f2fs_unlock_all                    -f2fs_sync_file
                                       -f2fs_write_inode
                                        -f2fs_inode_synced
    -f2fs_sync_inode_meta
     -sync_node_pages
                                        -set_page_drity

In this case, if sudden power off without next new checkpoint,
the last inode page update will lost. wb_writeback is same with
fsync.

Yunlei also reproduced the bug by:

@@ -366,7 +366,7 @@ int update_inode(struct inode *inode, struct page *node_page)
        struct extent_tree *et = F2FS_I(inode)->extent_tree;

        f2fs_inode_synced(inode);
-
+       msleep(10000);
        f2fs_wait_on_page_writeback(node_page, NODE, true);

shell 1:                                       shell2:

dd if=/dev/zero of=./test bs=1M count=10
sync
echo "hello" >> ./test
fsync test  // sleep 10s
                                               sync //return quickly
echo c > /proc/sysrq-trigger
Signed-off-by: NYunlei He <heyunlei@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

As Jia-Ju Bai reported:

"According to fs/f2fs/trace.c, the kernel module may sleep under a spinlock.
The function call path is:
f2fs_trace_pid (acquire the spinlock)
   f2fs_radix_tree_insert
     cond_resched --> may sleep

I do not find a good way to fix it, so I only report.
This possible bug is found by my static analysis tool (DSAC) and my code
review."

Obviously, it's problemetic to schedule in critical region of spinlock,
which will cause uninterruptable sleep if there is no waker.

This patch changes to use mutex lock intead of spinlock to avoid this
condition.
Reported-by: NJia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

No need return value in restore summary process
Signed-off-by: NYunlei He <heyunlei@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Since the variable release is only nonzero when another unlikely
case occurs, use unlikely() on it seems logical.
Signed-off-by: NFan li <fanofcode.li@samsung.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

There is no caller cares about return value of truncate_data_blocks_range,
remove it.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

f2fs_map_blocks():

if (blkaddr == NEW_ADDR || blkaddr == NULL_ADDR) {
	if (create) {
		...
	} else {
		...
		if (flag == F2FS_GET_BLOCK_FIEMAP &&
					blkaddr == NULL_ADDR) {
			...
		}
		if (flag != F2FS_GET_BLOCK_FIEMAP ||
					blkaddr != NEW_ADDR)
			goto sync_out;
	}

It means we can break the loop in cases of:
a) flag != F2FS_GET_BLOCK_FIEMAP or
b) flag == F2FS_GET_BLOCK_FIEMAP && blkaddr == NULL_ADDR

Condition b) is the same as previous one, so merge operations of them
for readability.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

f2fs_chksum and f2fs_crc32 use the same 'crc32' crypto engine, also
their implementation are almost the same, except with different
shash description context.

Introduce __f2fs_crc32 to wrap the common codes, and reuse it in
f2fs_chksum and f2fs_crc32.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In fill_super, if we fail to call f2fs_build_stats(), it needs to detach
from global f2fs shrink list, otherwise once system starts to shrink slab
cache, we will encounter below panic:

BUG: unable to handle kernel paging request at 00007d35
Oops: 0002 [#1] PREEMPT SMP
EIP: __lock_acquire+0x70/0x12c0
Call Trace:
 lock_acquire+0xae/0x220
 mutex_trylock+0xc5/0xf0
 f2fs_shrink_count+0x32/0xb0 [f2fs]
 shrink_slab+0xf1/0x5b0
 drop_slab_node+0x35/0x60
 drop_slab+0xf/0x20
 drop_caches_sysctl_handler+0x79/0xc0
 proc_sys_call_handler+0xa4/0xc0
 proc_sys_write+0x1f/0x30
 __vfs_write+0x24/0x150
 SyS_write+0x44/0x90
 do_fast_syscall_32+0xa1/0x1ca
 entry_SYSENTER_32+0x4c/0x7b

In addition, this patch relocates f2fs_join_shrinker in fill_super to
avoid unneeded error handling of it.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Use f2fs_k{m,z}alloc as much as possible to increase fault injection
points.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch supports to inject fault into kvmalloc/kvzalloc.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch introduces f2fs_kzalloc based on f2fs_kmalloc in order to
support error injection for kzalloc().
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Avoid checking is_inode repeatedly, and make the logic
a little bit clearer.
Signed-off-by: NFan li <fanofcode.li@samsung.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

When blocks are allocated for direct write, select the type of
segment using the kiocb hint. But if an inode has FI_NO_ALLOC,
use the inode hint.
Signed-off-by: NHyunchul Lee <cheol.lee@lge.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

atomic_t variables are currently used to implement reference
counters with the following properties:
 - counter is initialized to 1 using atomic_set()
 - a resource is freed upon counter reaching zero
 - once counter reaches zero, its further
   increments aren't allowed
 - counter schema uses basic atomic operations
   (set, inc, inc_not_zero, dec_and_test, etc.)

Such atomic variables should be converted to a newly provided
refcount_t type and API that prevents accidental counter overflows
and underflows. This is important since overflows and underflows
can lead to use-after-free situation and be exploitable.

The variable posix_acl.a_refcount is used as pure reference counter.
Convert it to refcount_t and fix up the operations.

**Important note for maintainers:

Some functions from refcount_t API defined in lib/refcount.c
have different memory ordering guarantees than their atomic
counterparts.
The full comparison can be seen in
https://lkml.org/lkml/2017/11/15/57 and it is hopefully soon
in state to be merged to the documentation tree.
Normally the differences should not matter since refcount_t provides
enough guarantees to satisfy the refcounting use cases, but in
some rare cases it might matter.
Please double check that you don't have some undocumented
memory guarantees for this variable usage.

For the posix_acl.a_refcount it might make a difference
in following places:
 - get_cached_acl(): increment in refcount_inc_not_zero() only
   guarantees control dependency on success vs. fully ordered
   atomic counterpart. However this operation is performed under
   rcu_read_lock(), so this should be fine.
 - posix_acl_release(): decrement in refcount_dec_and_test() only
   provides RELEASE ordering and control dependency on success
   vs. fully ordered atomic counterpart
Suggested-by: NKees Cook <keescook@chromium.org>
Reviewed-by: NDavid Windsor <dwindsor@gmail.com>
Reviewed-by: NHans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: NElena Reshetova <elena.reshetova@intel.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

f2fs: remove repeated f2fs_bug_on which has already existed
      in function invalidate_blocks.
Signed-off-by: NZhikang Zhang <zhangzhikang1@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Remove the variable page_idx which no one would miss.
Signed-off-by: NFan li <fanofcode.li@samsung.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

test/generic/208 reports a potential deadlock as below:

Chain exists of:
  &mm->mmap_sem --> &fi->i_mmap_sem --> &fi->dio_rwsem[WRITE]

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&fi->dio_rwsem[WRITE]);
                               lock(&fi->i_mmap_sem);
                               lock(&fi->dio_rwsem[WRITE]);
  lock(&mm->mmap_sem);

This patch changes the lock dependency as below in fallocate() to
fix this issue:
- dio_rwsem
 - i_mmap_sem

Fixes: bb06664a ("f2fs: avoid race in between GC and block exchange")
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Commit d260081c ("f2fs: change recovery policy of xattr node block")
removes the use of blkaddr, which is no longer used. So remove the
parameter.
Signed-off-by: NSheng Yong <shengyong1@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

If there is not enough space left, f2fs_preallocate_blocks may only
preallocte partial blocks. As a result, the write operation fails
but i_blocks is not 0.  To avoid this, f2fs should write data in
non-preallocation way and write as many data as the size of i_blocks.
Signed-off-by: NSheng Yong <shengyong1@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch introduces a sysfs interface readdir_ra to enable/disable
readaheading inode block in f2fs_readdir. When readdir_ra is enabled,
it improves the performance of "readdir + stat".

For 300,000 files:
	time find /data/test > /dev/null
disable readdir_ra: 1m25.69s real  0m01.94s user  0m50.80s system
enable  readdir_ra: 0m18.55s real  0m00.44s user  0m15.39s system
Signed-off-by: NSheng Yong <shengyong1@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>