For encrypted inode, if user overwrites data of the inode, f2fs will read
encrypted data into page cache, and then do the decryption.

However reader can race with overwriter, and it will see encrypted data
which has not been decrypted by overwriter yet. Fix it by moving decrypting
work to background and keep page non-uptodated until data is decrypted.

Thread A				Thread B
- f2fs_file_write_iter
 - __generic_file_write_iter
  - generic_perform_write
   - f2fs_write_begin
    - f2fs_submit_page_bio
					- generic_file_read_iter
					 - do_generic_file_read
					  - lock_page_killable
					  - unlock_page
					  - copy_page_to_iter
					  hit the encrypted data in updated page
    - lock_page
    - fscrypt_decrypt_page
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

The f2fs_map_blocks is very related to the performance, so let's avoid any
latency to read ahead node pages.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Let's keep more node/meta pages in run time.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

The readahead nat pages are more likely to be reclaimed quickly, so it'd better
to gather more free nids in advance.

And, let's keep some free nids as much as possible.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

If mkfs.f2fs gives a feature flag for host-managed SMR, we can set mode=lfs
by default.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Let's store orphan inode pages right away.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

If there is no dentry, we can report its error correctly.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

If dotdot directory is corrupted, its slot may be ocupied by another
file. In this case, dentry[1] is not the parent directory. Rename and
cross-rename will update the inode in dentry[1] incorrectly.   This
patch finds dotdot dentry by name.
Signed-off-by: Sheng Yong <shengyong1@huawei.com>
[Jaegeuk Kim: remove wron bug_on]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

mkdir                        sync_dirty_inode
 - init_inode_metadata
   - lock_page(node)
   - make_empty_dir
                             - filemap_fdatawrite()
                              - do_writepages
                              - lock_page(data)
                              - write_page(data)
                               - lock_page(node)
   - f2fs_init_acl
    - error
   - truncate_inode_pages
    - lock_page(data)

So, we don't need to truncate data pages in this error case, which will
be done by f2fs_evict_inode.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This mount option is to enable original log-structured filesystem forcefully.
So, there should be no random writes for main area.

Especially, this supports host-managed SMR device.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

If a segment in a section is clean or prefreed, we don't need to get its summary
and do gc.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

In f2fs, we don't need to keep block plugging for NODE and DATA writes, since
we already merged bios as much as possible.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

There is a data race between allocate_data_block() and f2fs_sbumit_page_mbio(),
which incur unnecessary reversed bio submission.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

If EIO occurred, we need to set all the mapping to avoid any further IOs.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This is to avoid cache entry management overhead including radix tree.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This should be 1%, 10MB / 1GB.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

FI_DIRTY_INODE flag is not covered by inode page lock, so it can be unset
at any time like below.

Thread #1                        Thread #2
- lock_page(ipage)
- update i_fields
                                 - update i_size/i_blocks/and so on
				 - set FI_DIRTY_INODE
- reset FI_DIRTY_INODE
- set_page_dirty(ipage)

In this case, we can lose the latest i_field information.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

We don't need lock parameter, which is always true.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

The number should be covered by spin_lock. Otherwise we can see wrong count
in f2fs_stat.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Remove deprecated paramter.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Previously, f2fs_write_data_pages() calls __f2fs_writepage() which calls
f2fs_write_data_page().
If f2fs_write_data_page() returns AOP_WRITEPAGE_ACTIVATE, __f2fs_writepage()
calls mapping_set_error(). But, this should not happen at every time, since
sometimes f2fs_write_data_page() tries to skip writing pages without error.
For example, volatile_write() gives EIO all the time, as Shuoran Liu pointed
out.
Reported-by: Shuoran Liu <liushuoran@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Now we can report an error to f2fs_lookup given by f2fs_find_entry.
Suggested-by: He YunLei <heyunlei@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Commit aaf96075 ("f2fs: check node page
contents all the time") pointed out that "sometimes it was reported that
its contents was missing", so it checks the page's mapping and contents.
When "nid != nid_of_node(page)", ERR_PTR(-EIO) will be returned to the
caller. However, commit e1c51b9f ("f2fs:
clean up node page updating flow") moves "nid != nid_of_node(page)" test
to "f2fs_bug_on(sbi, nid != nid_of_node(page))", this will return a
wrong page to the caller when F2FS_CHECK_FS is off when "sometimes it
was reported that its contents was missing" happens.

This patch restores to check node page contents all the time, and
returns the errno to make the caller known something is wrong and avoid
to use the page. This patch also moves f2fs_bug_on to its proper location.
Signed-off-by: Yunlong Song <yunlong.song@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

If there is no cold page, we don't need to do a loop to flush dirty
data pages.

On /dev/pmem0,

1. dd if=/dev/zero of=/mnt/test/testfile bs=1M count=2048 conv=fsync
 Before : 1.1 GB/s
 After  : 1.2 GB/s

2. dd if=/dev/zero of=/mnt/test/testfile bs=1M count=2048
 Before : 2.2 GB/s
 After  : 2.3 GB/s
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

For data pages, let's try to flush as much as possible in background.

On /dev/pmem0,

1. dd if=/dev/zero of=/mnt/test/testfile bs=1M count=2048 conv=fsync
 Before : 800 MB/s
 After  : 1.1 GB/s

2. dd if=/dev/zero of=/mnt/test/testfile bs=1M count=2048
 Before : 1.3 GB/s
 After  : 2.2 GB/s
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

If we get ENOMEM or EIO in f2fs_find_entry, we should stop right away.
Otherwise, for example, we can get duplicate directory entry by ->chash and
->clevel.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch removes writepages lock.
We can improve multi-threading performance.

tiobench, 32 threads, 4KB write per fsync on SSD
Before: 25.88 MB/s
After: 28.03 MB/s
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch sets flush_merge by default.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

If flush commands do not incur any congestion, we don't need to throw that to
dispatching queue which causes unnecessary latency.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch adds lazytime support.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

If roll-forward recovery can recover i_size, we don't need to update inode's
metadata during fsync.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch reduces to call them across the whole tree.
- sync_inode_page()
- update_inode_page()
- update_inode()
- f2fs_write_inode()

Instead, checkpoint will flush all the dirty inode metadata before syncing
node pages.
Note that, this is doable, since we call mark_inode_dirty_sync() for all
inode's field change which needs to update on-disk inode as well.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch registers all the inodes which have dirty metadata to sync when
checkpoint is doing.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch calls mark_inode_dirty_sync() for the following on-disk inode
changes.

 -> largest
 -> ctime/mtime/atime
 -> i_current_depth
 -> i_xattr_nid
 -> i_pino
 -> i_advise
 -> i_flags
 -> i_mode
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch introduces f2fs_i_links_write() to call mark_inode_dirty_sync() when
changing inode->i_links.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch introduces f2fs_i_blocks_write() to call mark_inode_dirty_sync() when
changing inode->i_blocks.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch introduces f2fs_i_size_write() to call mark_inode_dirty_sync() with
i_size_write().
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch refactors to use inode pointer for set_inode_flag and
clear_inode_flag.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This reverts commit b951a4ec.

 Conflicts:
	fs/f2fs/checkpoint.c