For a single device mount using a zoned block device, the zone
information for the device is stored in the sbi->devs single entry
array and sbi->s_ndevs is set to 1. This differs from a single device
mount using a regular block device which does not allocate sbi->devs
and sets sbi->s_ndevs to 0.

However, sbi->s_devs == 0 condition is used throughout the code to
differentiate a single device mount from a multi-device mount where
sbi->s_ndevs is always larger than 1. This results in problems with
single zoned block device volumes as these are treated as multi-device
mounts but do not have the start_blk and end_blk information set. One
of the problem observed is skipping of zone discard issuing resulting in
write commands being issued to full zones or unaligned to a zone write
pointer.

Fix this problem by simply treating the cases sbi->s_ndevs == 0 (single
regular block device mount) and sbi->s_ndevs == 1 (single zoned block
device mount) in the same manner. This is done by introducing the
helper function f2fs_is_multi_device() and using this helper in place
of direct tests of sbi->s_ndevs value, improving code readability.

Fixes: 7bb3a371 ("f2fs: Fix zoned block device support")
Cc: <stable@vger.kernel.org>
Signed-off-by: NDamien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In f2fs_mpage_readpages(), if page is beyond EOF, we should just
zero out it, but previously, before checking previous mapping
info, we missed to check filesize boundary, fix it.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

As Gao Xiang reported in bugzilla:

https://bugzilla.kernel.org/show_bug.cgi?id=202749

f2fs may skip pageout() due to incorrect page reference count.

The problem here is that MM defined the rule [1] very clearly that
once page was set with PG_private flag, we should increment the
refcount in that page, also main flows like pageout(), migrate_page()
will assume there is one additional page reference count if
page_has_private() returns true.

But currently, f2fs won't add/del refcount when changing PG_private
flag. Anyway, f2fs should follow MM's rule to make MM's related flows
running as expected.

[1] https://lore.kernel.org/lkml/2b19b3c4-2bc4-15fa-15cc-27a13e5c7af1@aol.com/Reported-by: NGao Xiang <gaoxiang25@huawei.com>
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Since 8c242db9 ("f2fs: fix stale ATOMIC_WRITTEN_PAGE private pointer"),
we've started to not skip clear private flag for atomic_write page
truncation, so removing old wrong comment in f2fs_invalidate_page().
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

For IPU path of f2fs_do_write_data_page(), in its error path, we
need to release encrypted page and fscrypt context, otherwise it
will cause memory leak.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Note that __GFP_ZERO is not supported for mempool_alloc,
which also documented in the mempool_alloc comments.
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Previously, we changed lock from cp_rwsem to node_change, it solved
the deadlock issue which was caused by below race condition:

Thread A			Thread B
- f2fs_setattr
 - f2fs_lock_op  -- read_lock
 - dquot_transfer
  - __dquot_transfer
   - dquot_acquire
    - commit_dqblk
     - f2fs_quota_write
      - f2fs_write_begin
       - f2fs_write_failed
				- write_checkpoint
				 - block_operations
				  - f2fs_lock_all  -- write_lock
        - f2fs_truncate_blocks
         - f2fs_lock_op  -- read_lock

But it breaks the sematics of cp_rwsem, in other callers like:
- f2fs_file_write_iter -> f2fs_write_begin -> f2fs_write_failed
- f2fs_direct_IO -> f2fs_write_failed

We allow to truncate dnode w/o cp_rwsem held, result in incorrect sit
bitmap update, which can cause further data corruption.

So this patch reverts previous fix implementation, and try to fix
deadlock by skipping calling f2fs_truncate_blocks() in f2fs_write_failed()
only for quota file, and keep the preallocated data/node in the tail of
quota file, we can expecte that the preallocated space can be used to
store quota info latter soon.

Fixes: af033b2a ("f2fs: guarantee journalled quota data by checkpoint")
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Signed-off-by: NSheng Yong <shengyong1@huawei.com>
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch introduces one extra iterator variable to bio_for_each_segment_all(),
then we can allow bio_for_each_segment_all() to iterate over multi-page bvec.

Given it is just one mechannical & simple change on all bio_for_each_segment_all()
users, this patch does tree-wide change in one single patch, so that we can
avoid to use a temporary helper for this conversion.
Reviewed-by: NOmar Sandoval <osandov@fb.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NMing Lei <ming.lei@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

This commit removes the f2fs specific f2fs_encrypted_inode() and makes
use of the generic IS_ENCRYPTED() macro to check for the encryption
status of an inode.
Acked-by: NChao Yu <yuchao0@huawei.com>
Reviewed-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NChandan Rajendra <chandan@linux.vnet.ibm.com>
Signed-off-by: NEric Biggers <ebiggers@google.com>

Fixes gcc '-Wunused-but-set-variable' warning:

fs/f2fs/data.c: In function 'f2fs_dio_submit_bio':
fs/f2fs/data.c:2585:6: warning:
 variable 'err' set but not used [-Wunused-but-set-variable]
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

All callers of migrate_page_move_mapping() now pass NULL for 'head'
argument.  Drop it.

Link: http://lkml.kernel.org/r/20181211172143.7358-7-jack@suse.czSigned-off-by: NJan Kara <jack@suse.cz>
Acked-by: NMel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

For all ordered cases in f2fs_wait_on_page_writeback(), we need to
check PageWriteback status, so let's clean up to relocate the check
into f2fs_wait_on_page_writeback().
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

One report says memalloc failure during mount.

 (unwind_backtrace) from [<c010cd4c>] (show_stack+0x10/0x14)
 (show_stack) from [<c049c6b8>] (dump_stack+0x8c/0xa0)
 (dump_stack) from [<c024fcf0>] (warn_alloc+0xc4/0x160)
 (warn_alloc) from [<c0250218>] (__alloc_pages_nodemask+0x3f4/0x10d0)
 (__alloc_pages_nodemask) from [<c0270450>] (kmalloc_order_trace+0x2c/0x120)
 (kmalloc_order_trace) from [<c03fa748>] (build_node_manager+0x35c/0x688)
 (build_node_manager) from [<c03de494>] (f2fs_fill_super+0xf0c/0x16cc)
 (f2fs_fill_super) from [<c02a5864>] (mount_bdev+0x15c/0x188)
 (mount_bdev) from [<c03da624>] (f2fs_mount+0x18/0x20)
 (f2fs_mount) from [<c02a68b8>] (mount_fs+0x158/0x19c)
 (mount_fs) from [<c02c3c9c>] (vfs_kern_mount+0x78/0x134)
 (vfs_kern_mount) from [<c02c76ac>] (do_mount+0x474/0xca4)
 (do_mount) from [<c02c8264>] (SyS_mount+0x94/0xbc)
 (SyS_mount) from [<c0108180>] (ret_fast_syscall+0x0/0x48)
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

If IPU failed, nothing is commited, we should end page writeback.
Signed-off-by: NSheng Yong <shengyong1@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Previously, we added a parameter @map.m_may_create to trigger OPU
allocation and call f2fs_balance_fs() correctly.

But in get_more_blocks(), @create has been overwritten by below code.
So the function f2fs_map_blocks() will not allocate new block address
but directly go out. Meanwile,there are several functions calling
f2fs_map_blocks() directly and @map.m_may_create not initialized.
CODE:
create = dio->op == REQ_OP_WRITE;
	if (dio->flags & DIO_SKIP_HOLES) {
		if (fs_startblk <= ((i_size_read(dio->inode) - 1) >>
						i_blkbits))
			create = 0;
	}

This patch fixes it.
Signed-off-by: NJia Zhu <zhujia13@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Previously, we allocated a new block address for OPU mode in direct_IO.

But the new address couldn't be assigned to @map->m_pblk correctly.

This patch fix it.

Cc: <stable@vger.kernel.org>
Fixes: 511f52d02f05 ("f2fs: allow out-place-update for direct IO in LFS mode")
Signed-off-by: NJia Zhu <zhujia13@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

The following race could lead to inconsistent SIT bitmap:

Task A                          Task B
======                          ======
f2fs_write_checkpoint
  block_operations
    f2fs_lock_all
      down_write(node_change)
      down_write(node_write)
      ... sync ...
      up_write(node_change)
                                f2fs_file_write_iter
                                  set_inode_flag(FI_NO_PREALLOC)
                                  ......
                                  f2fs_write_begin(index=0, has inline data)
                                    prepare_write_begin
                                      __do_map_lock(AIO) => down_read(node_change)
                                      f2fs_convert_inline_page => update SIT
                                      __do_map_lock(AIO) => up_read(node_change)
  f2fs_flush_sit_entries <= inconsistent SIT
  finish write checkpoint
  sudden-power-off

If SPO occurs after checkpoint is finished, SIT bitmap will be set
incorrectly.
Signed-off-by: NSheng Yong <shengyong1@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Previously, when f2fs finds which temp bio cache owns the target page,
it will flush all the three temp bio caches, but we only need to flush
one single bio cache indeed, which can help to keep bio merged.
Signed-off-by: NYunlong Song <yunlong.song@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In get_more_blocks(), we may override @create as below code:

	create = dio->op == REQ_OP_WRITE;
	if (dio->flags & DIO_SKIP_HOLES) {
		if (fs_startblk <= ((i_size_read(dio->inode) - 1) >>
						i_blkbits))
			create = 0;
	}

But in f2fs_map_blocks(), we only trigger f2fs_balance_fs() if @create
is 1, so in LFS mode, dio overwrite under LFS mode can easily run out
of free segments, result in below panic.

 Call Trace:
  allocate_segment_by_default+0xa8/0x270 [f2fs]
  f2fs_allocate_data_block+0x1ea/0x5c0 [f2fs]
  __allocate_data_block+0x306/0x480 [f2fs]
  f2fs_map_blocks+0x6f6/0x920 [f2fs]
  __get_data_block+0x4f/0xb0 [f2fs]
  get_data_block_dio_write+0x50/0x60 [f2fs]
  do_blockdev_direct_IO+0xcd5/0x21e0
  __blockdev_direct_IO+0x3a/0x3c
  f2fs_direct_IO+0x1ff/0x4a0 [f2fs]
  generic_file_direct_write+0xd9/0x160
  __generic_file_write_iter+0xbb/0x1e0
  f2fs_file_write_iter+0xaf/0x220 [f2fs]
  __vfs_write+0xd0/0x130
  vfs_write+0xb2/0x1b0
  SyS_pwrite64+0x69/0xa0
  ? vtime_user_exit+0x29/0x70
  do_syscall_64+0x6e/0x160
  entry_SYSCALL64_slow_path+0x25/0x25
 RIP: new_curseg+0x36f/0x380 [f2fs] RSP: ffffac570393f7a8

So this patch introduces a parameter map.m_may_create to indicate that
f2fs_map_blocks() is called from write or read path, which can give the
right hint to let f2fs_map_blocks() trigger OPU allocation and call
f2fs_balanc_fs() correctly.

BTW, it disables physical address preallocation for direct IO in
f2fs_preallocate_blocks, which is redundant to OPU allocation of
f2fs_map_blocks.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds f2fs_dio_submit_bio() to hook submit_io/end_io functions
in direct IO path, in order to account DIO.

Later, we will add this count into is_idle() to let background GC/Discard
thread be aware of DIO.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

For journalled quota mode, let checkpoint to flush dquot dirty data
and quota file data to guarntee persistence of all quota sysfile in
last checkpoint, by this way, we can avoid corrupting quota sysfile
when encountering SPO.

The implementation is as below:

1. add a global state SBI_QUOTA_NEED_FLUSH to indicate that there is
cached dquot metadata changes in quota subsystem, and later checkpoint
should:
 a) flush dquot metadata into quota file.
 b) flush quota file to storage to keep file usage be consistent.

2. add a global state SBI_QUOTA_NEED_REPAIR to indicate that quota
operation failed due to -EIO or -ENOSPC, so later,
 a) checkpoint will skip syncing dquot metadata.
 b) CP_QUOTA_NEED_FSCK_FLAG will be set in last cp pack to give a
    hint for fsck repairing.

3. add a global state SBI_QUOTA_SKIP_FLUSH, in checkpoint, if quota
data updating is very heavy, it may cause hungtask in block_operation().
To avoid this, if our retry time exceed threshold, let's just skip
flushing and retry in next checkpoint().
Signed-off-by: NWeichao Guo <guoweichao@huawei.com>
Signed-off-by: NChao Yu <yuchao0@huawei.com>
[Jaegeuk Kim: avoid warnings and set fsck flag]
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Direct IO can be used in case of hardware encryption. The following
scenario results into data corruption issue in this path -

Thread A -                          Thread B-
-> write file#1 in direct IO
                                    -> GC gets kicked in
                                    -> GC submitted bio on meta mapping
				       for file#1, but pending completion
-> write file#1 again with new data
   in direct IO
                                    -> GC bio gets completed now
                                    -> GC writes old data to the new
                                       location and thus file#1 is
				       corrupted.

Fix this by submitting and waiting for pending io on meta mapping
for direct IO case in f2fs_map_blocks().
Signed-off-by: NSahitya Tummala <stummala@codeaurora.org>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

We need to drop PG_checked flag on page as well when we clear PG_uptodate
flag, in order to avoid treating the page as GCing one later.
Signed-off-by: NWeichao Guo <guoweichao@huawei.com>
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This reverts commit 66110abc.

If we clear the cold data flag out of the writeback flow, we can miscount
-1 by end_io, which incurs a deadlock caused by all I/Os being blocked during
heavy GC.

Balancing F2FS Async:
 - IO (CP:    1, Data:   -1, Flush: (   0    0    1), Discard: (   ...

GC thread:                              IRQ
- move_data_page()
 - set_page_dirty()
  - clear_cold_data()
                                        - f2fs_write_end_io()
                                         - type = WB_DATA_TYPE(page);
                                           here, we get wrong type
                                         - dec_page_count(sbi, type);
 - f2fs_wait_on_page_writeback()

Cc: <stable@vger.kernel.org>
Reported-and-Tested-by: NPark Ju Hyung <qkrwngud825@gmail.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds issued read IO counts which is under block layer.

Chao modified a bit, since:

Below race can cause reversed reference on F2FS_RD_DATA, there is
the same issue in f2fs_submit_page_bio(), fix them by relocate
__submit_bio() and inc_page_count.

Thread A			Thread B
- f2fs_write_begin
 - f2fs_submit_page_read
 - __submit_bio
				- f2fs_read_end_io
				 - __read_end_io
				 - dec_page_count(, F2FS_RD_DATA)
 - inc_page_count(, F2FS_RD_DATA)
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Now, we have supported cgroup writeback, it depends on correctly IO
account of specified filesystem.

But in commit d1b3e72d ("f2fs: submit bio of in-place-update pages"),
we split write paths from f2fs_submit_page_mbio() to two:
- f2fs_submit_page_bio() for IPU path
- f2fs_submit_page_bio() for OPU path

But still we account write IO only in f2fs_submit_page_mbio(), result in
incorrect IO account, fix it by adding missing IO account in IPU path.

Fixes: d1b3e72d ("f2fs: submit bio of in-place-update pages")
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Below race can cause reversed reference on dirty count, fix it by
relocating __submit_bio() and inc_page_count().

Thread A				Thread B
- f2fs_inplace_write_data
 - f2fs_submit_page_bio
  - __submit_bio
					- f2fs_write_end_io
					 - dec_page_count
  - inc_page_count

Cc: <stable@vger.kernel.org>
Fixes: d1b3e72d ("f2fs: submit bio of in-place-update pages")
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This is a straightforward conversion.
Signed-off-by: NMatthew Wilcox <willy@infradead.org>

Removes sparse warnings.
Signed-off-by: NMatthew Wilcox <willy@infradead.org>

Note that, it requires "f2fs: return correct errno in f2fs_gc".

This adds a lightweight non-persistent snapshotting scheme to f2fs.

To use, mount with the option checkpoint=disable, and to return to
normal operation, remount with checkpoint=enable. If the filesystem
is shut down before remounting with checkpoint=enable, it will revert
back to its apparent state when it was first mounted with
checkpoint=disable. This is useful for situations where you wish to be
able to roll back the state of the disk in case of some critical
failure.
Signed-off-by: NDaniel Rosenberg <drosen@google.com>
[Jaegeuk Kim: use SB_RDONLY instead of MS_RDONLY]
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

When running fault injection test, I hit somewhat wrong behavior in f2fs_gc ->
gc_data_segment():

0. fault injection generated some PageError'ed pages

1. gc_data_segment
 -> f2fs_get_read_data_page(REQ_RAHEAD)

2. move_data_page
 -> f2fs_get_lock_data_page()
  -> f2f_get_read_data_page()
   -> f2fs_submit_page_read()
    -> submit_bio(READ)
  -> return EIO due to PageError
  -> fail to move data
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Normally, DIO uses in-pllace-update, but in LFS mode, f2fs doesn't
allow triggering any in-place-update writes, so we fallback direct
write to buffered write, result in bad performance of large size
write.

This patch adds to support triggering out-place-update for direct IO
to enhance its performance.

Note that it needs to exclude direct read IO during direct write,
since new data writing to new block address will no be valid until
write finished.

storage: zram

time xfs_io -f -d /mnt/f2fs/file -c "pwrite 0 1073741824" -c "fsync"

Before:
real	0m13.061s
user	0m0.327s
sys	0m12.486s

After:
real	0m6.448s
user	0m0.228s
sys	0m6.212s
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Thread A				Thread B
- f2fs_vm_page_mkwrite
					- f2fs_setattr
					 - down_write(i_mmap_sem)
					 - truncate_setsize
					 - f2fs_truncate
					 - up_write(i_mmap_sem)
 - f2fs_reserve_block
 reserve NEW_ADDR
 - skip dirty page due to truncation

1. we don't need to rserve new block address for a truncated page.
2. dn.data_blkaddr is used out of node page lock coverage.

Refactor ->page_mkwrite() flow to fix above issues:
- use __do_map_lock() to avoid racing checkpoint()
- lock data page in prior to dnode page
- cover f2fs_reserve_block with i_mmap_sem lock
- wait page writeback before zeroing page
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

There is one case that we can leave bio in f2fs, result in hanging
page writeback waiter.

Thread A				Thread B
- f2fs_write_cache_pages
 - f2fs_submit_page_write
 page #0 cached in bio #0 of cold log
 - f2fs_submit_page_write
 page #1 cached in bio #1 of warm log
					- f2fs_write_cache_pages
					 - f2fs_submit_page_write
					 bio is full, submit bio #1 contain page #1
 - f2fs_submit_merged_write_cond(, page #1)
 fail to submit bio #0 due to page #1 is not in any cached bios.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This is related to
ee70daab ("xfs: update i_size after unwritten conversion in dio completion")

If we update i_size during dio_write, dio_read can read out stale data, which
breaks xfstests/465.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds to support injecting error for write IO, this can simulate
IO error like fail_make_request or dm_flakey does.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Remove the verbose license text from f2fs files and replace them with
SPDX tags.  This does not change the license of any of the code.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Sometimes, some merged IOs could get a chance to be submitted, resulting in
system hang in shutdown test. This issues IOs all the time after shutdown.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

1. Create a file in an encrypted directory
2. Do GC & drop caches
3. Read stale data before its bio for metapage was not issued yet
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

During GC, for each encrypted block, we will read block synchronously
into meta page, and then submit it into current cold data log area.

So this block read model with 4k granularity can make poor performance,
like migrating non-encrypted block, let's readahead encrypted block
as well to improve migration performance.

To implement this, we choose meta page that its index is old block
address of the encrypted block, and readahead ciphertext into this
page, later, if readaheaded page is still updated, we will load its
data into target meta page, and submit the write IO.

Note that for OPU, truncation, deletion, we need to invalid meta
page after we invalid old block address, to make sure we won't load
invalid data from target meta page during encrypted block migration.

for ((i = 0; i < 1000; i++))
do {
        xfs_io -f /mnt/f2fs/dir/$i -c "pwrite 0 128k" -c "fsync";
} done

for ((i = 0; i < 1000; i+=2))
do {
        rm /mnt/f2fs/dir/$i;
} done

ret = ioctl(fd, F2FS_IOC_GARBAGE_COLLECT, 0);

Before:
              gc-6549  [001] d..1 214682.212797: block_rq_insert: 8,32 RA 32768 () 786400 + 64 [gc]
              gc-6549  [001] d..1 214682.212802: block_unplug: [gc] 1
              gc-6549  [001] .... 214682.213892: block_bio_queue: 8,32 R 67494144 + 8 [gc]
              gc-6549  [001] .... 214682.213899: block_getrq: 8,32 R 67494144 + 8 [gc]
              gc-6549  [001] .... 214682.213902: block_plug: [gc]
              gc-6549  [001] d..1 214682.213905: block_rq_insert: 8,32 R 4096 () 67494144 + 8 [gc]
              gc-6549  [001] d..1 214682.213908: block_unplug: [gc] 1
              gc-6549  [001] .... 214682.226405: block_bio_queue: 8,32 R 67494152 + 8 [gc]
              gc-6549  [001] .... 214682.226412: block_getrq: 8,32 R 67494152 + 8 [gc]
              gc-6549  [001] .... 214682.226414: block_plug: [gc]
              gc-6549  [001] d..1 214682.226417: block_rq_insert: 8,32 R 4096 () 67494152 + 8 [gc]
              gc-6549  [001] d..1 214682.226420: block_unplug: [gc] 1
              gc-6549  [001] .... 214682.226904: block_bio_queue: 8,32 R 67494160 + 8 [gc]
              gc-6549  [001] .... 214682.226910: block_getrq: 8,32 R 67494160 + 8 [gc]
              gc-6549  [001] .... 214682.226911: block_plug: [gc]
              gc-6549  [001] d..1 214682.226914: block_rq_insert: 8,32 R 4096 () 67494160 + 8 [gc]
              gc-6549  [001] d..1 214682.226916: block_unplug: [gc] 1

After:
              gc-5678  [003] .... 214327.025906: block_bio_queue: 8,32 R 67493824 + 8 [gc]
              gc-5678  [003] .... 214327.025908: block_bio_backmerge: 8,32 R 67493824 + 8 [gc]
              gc-5678  [003] .... 214327.025915: block_bio_queue: 8,32 R 67493832 + 8 [gc]
              gc-5678  [003] .... 214327.025917: block_bio_backmerge: 8,32 R 67493832 + 8 [gc]
              gc-5678  [003] .... 214327.025923: block_bio_queue: 8,32 R 67493840 + 8 [gc]
              gc-5678  [003] .... 214327.025925: block_bio_backmerge: 8,32 R 67493840 + 8 [gc]
              gc-5678  [003] .... 214327.025932: block_bio_queue: 8,32 R 67493848 + 8 [gc]
              gc-5678  [003] .... 214327.025934: block_bio_backmerge: 8,32 R 67493848 + 8 [gc]
              gc-5678  [003] .... 214327.025941: block_bio_queue: 8,32 R 67493856 + 8 [gc]
              gc-5678  [003] .... 214327.025943: block_bio_backmerge: 8,32 R 67493856 + 8 [gc]
              gc-5678  [003] .... 214327.025953: block_bio_queue: 8,32 R 67493864 + 8 [gc]
              gc-5678  [003] .... 214327.025955: block_bio_backmerge: 8,32 R 67493864 + 8 [gc]
              gc-5678  [003] .... 214327.025962: block_bio_queue: 8,32 R 67493872 + 8 [gc]
              gc-5678  [003] .... 214327.025964: block_bio_backmerge: 8,32 R 67493872 + 8 [gc]
              gc-5678  [003] .... 214327.025970: block_bio_queue: 8,32 R 67493880 + 8 [gc]
              gc-5678  [003] .... 214327.025972: block_bio_backmerge: 8,32 R 67493880 + 8 [gc]
              gc-5678  [003] .... 214327.026000: block_bio_queue: 8,32 WS 34123776 + 2048 [gc]
              gc-5678  [003] .... 214327.026019: block_getrq: 8,32 WS 34123776 + 2048 [gc]
              gc-5678  [003] d..1 214327.026021: block_rq_insert: 8,32 R 131072 () 67493632 + 256 [gc]
              gc-5678  [003] d..1 214327.026023: block_unplug: [gc] 1
              gc-5678  [003] d..1 214327.026026: block_rq_issue: 8,32 R 131072 () 67493632 + 256 [gc]
              gc-5678  [003] .... 214327.026046: block_plug: [gc]
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>