Now, we use ra_meta_pages to reads continuous physical blocks as much as
possible to improve performance of following reads. However, ra_meta_pages
uses a synchronous readahead approach by submitting bio with READ, as READ
is with high priority, it can not be used in the case of preloading blocks,
and it's not sure when these RAed pages will be used.

This patch supports asynchronous readahead in ra_meta_pages by tagging bio
with READA flag in order to allow preloading.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In recovery or checkpoint flow, we grab pages temperarily in meta inode's
mapping for caching temperary data, actually, datas in these pages were
not meta data of f2fs, but still we tag them with REQ_META flag. However,
lower device like eMMC may do some optimization for data of such type.
So in order to avoid wrong optimization, we'd better remove such flag
for temperary non-meta pages.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Protecting recovery flow by using cp_rwsem is not needed, since we have
prevent triggering any checkpoint by locking cp_mutex previously.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

We have potential overflow issue when calculating size of object, when
we left shift index with PAGE_CACHE_SHIFT bits, if type of index has only
32-bits space in 32-bit architecture, left shifting will incur overflow,
i.e:

pgoff_t index =  0xFFFFFFFF;
loff_t size = index << PAGE_CACHE_SHIFT;
size: 0xFFFFF000

So we should cast index with 64-bits type to avoid this issue.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

We should not write node pages when deleting orphan inodes.
In order to do that, we can eaisly set POR_DOING flag earlier before entering
orphan inode routine.
Reviewed-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

When testing with generic/101 in xfstests, error message outputed as below:

    --- tests/generic/101.out
    +++ results//generic/101.out.bad
    @@ -10,10 +10,14 @@
     File foo content after log replay:
     0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa
     *
    -0200000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    +0200000 bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb
     *
     0372000
    ...
    (Run 'diff -u tests/generic/101.out results/generic/101.out.bad'  to see the entire diff)

The test flow is like below:
1. pwrite foo -S 0xaa 0 64K
2. pwrite foo -S 0xbb 64K 61K
3. sync
4. truncate foo 64K
5. truncate foo 125K
6. fsync foo
7. flakey drop writes
8. umount

After this test, we expect the data of recovered file will have the first
64k of data filling with value 0xaa and the next 61k of data filling with
value 0x00 because we have fsynced it before dropping writes in dm.

In f2fs, during recovering, we will only recover the valid block address
in direct node page if it is marked as a fsynced dnode, but block address
which means invalid/reserved (with value NULL_ADDR/NEW_ADDR) will not be
recovered. So, the file recovered shows its incorrect data 0xbb in range of
[61k, 125k].

In this patch, we fix to recover invalid/reserved block during recover flow.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

To avoid meeting garbage data in next free node block at the end of warm
node chain when doing recovery, we will try to zero out that invalid block.

If the device is not support discard, our way for zeroing out block is:
grabbing a temporary zeroed page in meta inode, then, issue write request
with this page.

But, we forget to release that temporary page, so our memory usage will
increase without gaining any hit ratio benefit, so it's better to free it
for saving memory.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch clean up codes through:
1.rename f2fs_replace_block to __f2fs_replace_block().
2.introduce new f2fs_replace_block() to include __f2fs_replace_block()
and some common related codes around __f2fs_replace_block().

Then, newly introduced function f2fs_replace_block can be used by
following patch.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds a bit flag to indicate whether or not i_name in the inode
is encrypted.

If this name is encrypted, we can't do recover_dentry during roll-forward.
So, f2fs_sync_file() needs to do checkpoint, if this will be needed in future.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Introduce a generic function replace_block base on recover_data_page,
and export it. So with it we can operate file's meta data which is in
CP/SSA area when we invoke fallocate with FALLOC_FL_COLLAPSE_RANGE
flag.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Export is_valid_blkaddr() and use it to replace some codes for readability.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds CP_RECOVERY to remain recovery information for checkpoint.
And, it makes sure writing checkpoint in this case.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

During the roll-forward recovery, if we found a new data index written fsync
lastly, we need to recover new block address.
But, if that address was corrupted, we should not recover that.
Otherwise, f2fs gets kernel panic from:

 In check_index_in_prev_nodes(),

    sentry = get_seg_entry(sbi, segno);
             --------------------------> out-of-range segno.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

If there are multiple fsynced dnodes having a dent flag, roll-forward routine
sets FI_INC_LINK for their inode, and recovery_dentry increases its link count
accordingly.
That results in normal file having a link count as 2, so we can't unlink those
files.

This was added to handle several inode blocks having same inode number with
different directory paths.
But, current f2fs doesn't replay all of path changes and only recover its dentry
for the last fsynced inode block.
So, there is no reason to do this.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

If f2fs was corrupted with missing dot dentries, it needs to recover them after
fsck.f2fs detection.

The underlying precedure is:

1. The fsck.f2fs remains F2FS_INLINE_DOTS flag in directory inode, if it detects
missing dot dentries.

2. When f2fs looks up the corrupted directory, it triggers f2fs_add_link with
proper inode numbers and their dot and dotdot names.

3. Once f2fs recovers the directory without errors, it removes F2FS_INLINE_DOTS
finally.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Previously, inode page is not correctly locked and unlocked in pair during
the roll-forward recovery.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Split __set_data_blkaddr from f2fs_update_extent_cache for readability.

Additionally rename __set_data_blkaddr to set_data_blkaddr for exporting.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

During the roll-forward recovery, -ENOENT for f2fs_iget can be skipped.
So, this error value should not be propagated.
Reviewed-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch removes obsolete code in which summary variable is not needed.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In this patch, we do these jobs:
1. rename {check,update}_extent_cache to {lookup,update}_extent_info;
2. introduce universal lookup/update interface of extent cache:
f2fs_{lookup,update}_extent_cache including above two real functions, then
export them to function callers.

So after above cleanup, we can add new rb-tree based extent cache into exported
interfaces.

v2:
 o remove "f2fs_" for inner function {lookup,update}_extent_info suggested by
   Jaegeuk Kim.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Currently, there are several variables with Boolean type as below:

struct f2fs_sb_info {
...
	int s_dirty;
	bool need_fsck;
	bool s_closing;
...
	bool por_doing;
...
}

For this there are some issues:
1. there are some space of f2fs_sb_info is wasted due to aligning after Boolean
   type variables by compiler.
2. if we continuously add new flag into f2fs_sb_info, structure will be messed
   up.

So in this patch, we try to:
1. switch s_dirty to Boolean type variable since it has two status 0/1.
2. merge s_dirty/need_fsck/s_closing/por_doing variables into s_flag.
3. introduce an enum type which can indicate different states of sbi.
4. use new introduced universal interfaces is_sbi_flag_set/{set,clear}_sbi_flag
   to operate flags for sbi.

After that, above issues will be fixed.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

During the recovery, any xattr blocks should not be found, since they are
written into cold log, not the warm node chain.
Reviewed-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch uses dn->data_blkaddr as a parameter for the destination block
address.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

To improve recovery speed, f2fs try to readahead many contiguous blocks in warm
node segment, but for most time, abnormal power-off do not occur frequently, so
when mount a normal power-off f2fs image, by contrary ra so many blocks and then
invalid them will hurt the performance of mount.
It's better to just ra the first next-block for normal condition.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch introduces f2fs_dentry_kunmap to clean up dirty codes.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Add inline dir functions into normal dir ops' function to handle inline ops.
Besides, we enable inline dir mode when a new dir inode is created if
inline_data option is on.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch exports some dir operations for inline dir, additionally introduces
f2fs_drop_nlink from f2fs_delete_entry for reusing by inline dir function.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch cleans up the existing and new macros for readability.

Rule is like this.

         ,-----------------------------------------> MAX_BLKADDR -,
         |  ,------------- TOTAL_BLKS ----------------------------,
         |  |                                                     |
         |  ,- seg0_blkaddr   ,----- sit/nat/ssa/main blkaddress  |
block    |  | (SEG0_BLKADDR)  | | | |   (e.g., MAIN_BLKADDR)      |
address  0..x................ a b c d .............................
            |                                                     |
global seg# 0...................... m .............................
            |                       |                             |
            |                       `------- MAIN_SEGS -----------'
            `-------------- TOTAL_SEGS ---------------------------'
                                    |                             |
 seg#                               0..........xx..................

= Note =
 o GET_SEGNO_FROM_SEG0 : blk address -> global segno
 o GET_SEGNO           : blk address -> segno
 o START_BLOCK         : segno -> starting block address
Reviewed-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch add a new data structure to control checkpoint parameters.
Currently, it presents the reason of checkpoint such as is_umount and normal
sync.
Reviewed-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

If same data is updated multiple times, we don't need to redo whole the
operations.
Let's just update the lastest one.
Reviewed-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

We can summarize the roll forward recovery scenarios as follows.

[Term] F: fsync_mark, D: dentry_mark

1. inode(x) | CP | inode(x) | dnode(F)
-> Update the latest inode(x).

2. inode(x) | CP | inode(F) | dnode(F)
-> No problem.

3. inode(x) | CP | dnode(F) | inode(x)
-> Recover to the latest dnode(F), and drop the last inode(x)

4. inode(x) | CP | dnode(F) | inode(F)
-> No problem.

5. CP | inode(x) | dnode(F)
-> The inode(DF) was missing. Should drop this dnode(F).

6. CP | inode(DF) | dnode(F)
-> No problem.

7. CP | dnode(F) | inode(DF)
-> If f2fs_iget fails, then goto next to find inode(DF).

8. CP | dnode(F) | inode(x)
-> If f2fs_iget fails, then goto next to find inode(DF).
   But it will fail due to no inode(DF).

So, this patch adds some missing points such as #1, #5, #7, and #8.
Signed-off-by: NHuang Ying <ying.huang@intel.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Previously, all the dnode pages should be read during the roll-forward recovery.
Even worsely, whole the chain was traversed twice.
This patch removes that redundant and costly read operations by using page cache
of meta_inode and readahead function as well.
Reviewed-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

If the inode is same and its data index are needed to truncate, we can fall into
double lock for its inode page via get_dnode_of_data.

Error case is like this.

1. write data 1, 2, 3, 4, 5 in inode #4.
2. write data 100, 102, 103, 104, 105 in dnode #6 of inode #4.
3. sync
4. update data 100->106 in dnode #6.
5. fsync inode #4.
6. power-cut

-> Then,
1. go back to #3's checkpoint
2. in do_recover_data, get_dnode_of_data() gets inode #4.
3. detect 100->106 in dnode #6.
4. check_index_in_prev_nodes tries to truncate 100 in dnode #6.
5. to trigger truncate_hole, get_dnode_of_data should grab inode #4.
6. detect *kernel hang*

This patch should resolve that bug.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

If any f2fs_bug_on is triggered, fsck.f2fs is needed.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds three inline functions to clean up dirty casting codes.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

I think we need to let the dirty node pages remain in the page cache instead
of rewriting them in their places.
So, after done with successful recovery, write_checkpoint will flush all of them
through the normal write path.
Through this, we can avoid potential error cases in terms of block allocation.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Any checkpoint should not be done during the core roll-forward procedure.
Especially, it includes error cases too.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

During the recovery, if an error like EIO or ENOMEM, f2fs_bug_on should skip.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch fixes not to skip xattr recovery and inline xattr/data recovery
order.
Reviewed-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

If an inode are fsynced multiple times with fsync & dent marks, this inode will
set FI_INC_LINK at find_fsync_dnodes during the recovery.
But, in recover_inode, recover_dentry doesn't clear that flag when multiple hits
were occurred.

So this patch removes the flag for the further consistency.
Reviewed-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>