There is an errorneous case during the recovery like below.

In recovery_dentry,
 1) dir = f2fs_iget();
 2) mark the dir with FI_DELAY_IPUT
 3) goto unmap_out

After the end of recovery routine, there is no dirty dentries so the dir cannot
be released by iput in remove_dirty_dir_inode.

This patch fixes such the bug case by handling the iget and iput in the
recovery_dentry procedure.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

We should set the error number correctly when we fail in recover_dentry(), so
the recover flow could stop for the reason as error number shows instead of
continuing.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

Introduce help macro ADDRS_PER_PAGE() to get the number of address pointers in
direct node or inode.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This patch removes list opeations in handling dirty dir inodes.
Previously, F2FS traverses whole the list of dirty dir inodes to check whether
there is an existing inode or not, resulting in heavy CPU overheads.

So this patch removes such the traverse operations by adding FI_DIRTY_DIR to
indicate the inode lies on the list or not.
Through this simple flag, we can remove redundant operations gracefully.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This patch use list_for_each_entry{_safe} instead of list_for_each{_safe} for
simplfying code.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

If a page is on writeback, f2fs can face with deadlock due to under writepages.
This is caused by merging IOs inside f2fs, so if it comes to detect, let's throw
merged IOs, which is implemented by f2fs_wait_on_page_writeback.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

Signed-off-by: NGu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This patch use existing macro F2FS_INODE/NEXT_FREE_BLKADDR to clean up some
codes.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This patch modifies flow a little bit to avoid the following build warnings.

src/fs/f2fs/recovery.c: In function ‘check_index_in_prev_nodes’:
src/fs/f2fs/recovery.c:288:51: warning: ‘sum.<U5390>.<U52f8>.ofs_in_node’ may
	be used uninitialized in this function [-Wmaybe-uninitialized]
src/fs/f2fs/recovery.c:260:23: warning: ‘sum.nid’ may be used uninitialized
	in this function [-Wmaybe-uninitialized]
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This patch adds GET_BLKOFF_FROM_SEG0 to clean up some codes.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

If a new xattr node page was allocated and its inode is fsynced, we should
recover the xattr node page during the roll-forward process after power-cut.
But, previously, f2fs didn't handle that case, resulting in kernel panic as
follows reported by Tom Li.

BUG: unable to handle kernel paging request at ffffc9001c861a98
IP: [<ffffffffa0295236>] check_index_in_prev_nodes+0x86/0x2d0 [f2fs]
Call Trace:
 [<ffffffff815ece9b>] ? printk+0x48/0x4a
 [<ffffffffa029626a>] recover_fsync_data+0xdca/0xf50 [f2fs]
 [<ffffffffa02873ae>] f2fs_fill_super+0x92e/0x970 [f2fs]
 [<ffffffff8112c9f8>] mount_bdev+0x1b8/0x200
 [<ffffffffa0286a80>] ? f2fs_remount+0x130/0x130 [f2fs]
 [<ffffffffa0285e40>] f2fs_mount+0x10/0x20 [f2fs]
 [<ffffffff8112d4de>] mount_fs+0x3e/0x1b0
 [<ffffffff810ef4eb>] ? __alloc_percpu+0xb/0x10
 [<ffffffff8114761f>] vfs_kern_mount+0x6f/0x120
 [<ffffffff811497b9>] do_mount+0x259/0xa90
 [<ffffffff810ead1d>] ? memdup_user+0x3d/0x80
 [<ffffffff810eadb3>] ? strndup_user+0x53/0x70
 [<ffffffff8114a2c9>] SyS_mount+0x89/0xd0
 [<ffffffff815feae2>] system_call_fastpath+0x16/0x1b

This patch adds a recovery function of xattr node pages.
Reported-by: NTom Li <biergaizi@members.fsf.org>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

Fixed a variety of trivial checkpatch warnings.  The only delta should
be some minor formatting on log strings that were split / too long.
Signed-off-by: NChris Fries <cfries@motorola.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This patch adds a inline_data recovery routine with the following policy.

[prev.] [next] of inline_data flag
   o       o  -> recover inline_data
   o       x  -> remove inline_data, and then recover data blocks
   x       o  -> remove inline_data, and then recover inline_data
   x       x  -> recover data blocks
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This patch introduces F2FS_INODE that returns struct f2fs_inode * from the inode
page.
By using this macro, we can remove unnecessary casting codes like below.

   struct f2fs_inode *ri = &F2FS_NODE(inode_page)->i;
-> struct f2fs_inode *ri = F2FS_INODE(inode_page);
Reviewed-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

In current flow, we will get Null return value of f2fs_find_entry in
recover_dentry when name.len is bigger than F2FS_NAME_LEN, and then we
still add this inode into its dir entry.
To avoid this situation, we must check filename length before we use it.

Another point is that we could remove the code of checking filename length
In f2fs_find_entry, because f2fs_lookup will be called previously to ensure of
validity of filename length.

V2:
 o add WARN_ON() as Jaegeuk Kim suggested.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This patch adds unlikely() macro into the most of codes.
The basic rule is to add that when:
- checking unusual errors,
- checking page mappings,
- and the other unlikely conditions.

Change log from v1:
 - Don't add unlikely for the NULL test and error test: advised by Andi Kleen.

Cc: Chao Yu <chao2.yu@samsung.com>
Cc: Andi Kleen <andi@firstfloor.org>
Reviewed-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

In find_fsync_dnodes() and recover_data(), our flow is like this:

->f2fs_submit_page_bio()
	-> f2fs_put_page()
		-> page_cache_release()	---- page->_count declined to zero.
->__free_pages()
	-> put_page_testzero() ---- page->_count will be declined again.

We will get a segment fault in put_page_testzero when CONFIG_DEBUG_VM
is on, or return MM with a bad page with wrong _count num.

So let's just release this page.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

Use inner macro GFP_F2FS_ZERO to instead of GFP_NOFS | __GFP_ZERO for
simplification of code.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This patch integrates redundant bio operations on read and write IOs.

1. Move bio-related codes to the top of data.c.
2. Replace f2fs_submit_bio with f2fs_submit_merged_bio, which handles read
   bios additionally.
3. Introduce __submit_merged_bio to submit the merged bio.
4. Change f2fs_readpage to f2fs_submit_page_bio.
5. Introduce f2fs_submit_page_mbio to integrate previous submit_read_page and
   submit_write_page.
Reviewed-by: NGu Zheng <guz.fnst@cn.fujitsu.com>
Reviewed-by: Chao Yu <chao2.yu@samsung.com >
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

If you want to remove unnecessary BUG_ONs, you can just turn off F2FS_CHECK_FS
in your kernel config.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

Signed-off-by: NHaicheng Li <haicheng.li@linux.intel.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

The fs_locks is used to block other ops(ex, recovery) when doing checkpoint.
And each other operate routine(besides checkpoint) needs to acquire a fs_lock,
there is a terrible problem here, if these are too many concurrency threads acquiring
fs_lock, so that they will block each other and may lead to some performance problem,
but this is not the phenomenon we want to see.
Though there are some optimization patches introduced to enhance the usage of fs_lock,
but the thorough solution is using a *rw_sem* to replace the fs_lock.
Checkpoint routine takes write_sem, and other ops take read_sem, so that we can block
other ops(ex, recovery) when doing checkpoint, and other ops will not disturb each other,
this can avoid the problem described above completely.
Because of the weakness of rw_sem, the above change may introduce a potential problem
that the checkpoint thread might get starved if other threads are intensively locking
the read semaphore for I/O.(Pointed out by Xu Jin)
In order to avoid this, a wait_list is introduced, the appending read semaphore ops
will be dropped into the wait_list if checkpoint thread is waiting for write semaphore,
and will be waked up when checkpoint thread gives up write semaphore.
Thanks to Kim's previous review and test, and will be very glad to see other guys'
performance tests about this patch.

V2:
  -fix the potential starvation problem.
  -use more suitable func name suggested by Xu Jin.
Signed-off-by: NGu Zheng <guz.fnst@cn.fujitsu.com>
[Jaegeuk Kim: adjust minor coding standard]
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

During recovery, orphan inodes are deleted via truncate_hole().
These orphans are added by recover_dentry() via f2fs_delete_entry().
However, f2fs_delete_entry() adds them via add_orphan_inode()
without calling acquire_orphan_inode() first.  This prevents the
counters from being incremented properly, which causes them to
underflow when remove_orphan_inode() is called later on.
Signed-off-by: NRuss Knize <rknize@motorola.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

Previously, recover_fsync_data still to write checkpoint when there is
nothing to recover with normal umount image.
It may reduce mount performance and flash memory lifetime, so let's remove
it.
Signed-off-by: NTan Shu <shu.tan@samsung.com>
Signed-off-by: NYu Chao <chao2.yu@samsung.com>
Reviewed-by: NGu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This patch enables the number of direct pointers inside on-disk inode block to
be changed dynamically according to the size of inline xattr space.

The number of direct pointers, ADDRS_PER_INODE, can be changed only if the file
has inline xattr flag.

The number of direct pointers that will be used by inline xattrs is defined as
F2FS_INLINE_XATTR_ADDRS.
Current patch assigns F2FS_INLINE_XATTR_ADDRS to 0 temporarily.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

alloc_page() returns a NULL on failure, it never returns an ERR_PTR.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This patch introduces a new inline function, cur_cp_version, to reduce redundant
codes.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

Introduce help function F2FS_NODE() to simplify the conversion of node_page to
f2fs_node.
Signed-off-by: NGu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

As destroy_fsync_dnodes() is a simple list-cleanup func, so delete the unused
and unrelated f2fs_sb_info argument of it.
Signed-off-by: NGu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This patch should fix the following bug reported by kbuild test robot.

fs/f2fs/recovery.c:233:33: sparse: incorrect type in assignment
(different base types)

parse warnings: (new ones prefixed by >>)

>> recovery.c:233: sparse: incorrect type in assignment (different base types)
   recovery.c:233:    expected unsigned int [unsigned] [assigned] ofs_in_node
   recovery.c:233:    got restricted __le16 [assigned] [usertype] ofs_in_node
>> recovery.c:238: sparse: incorrect type in assignment (different base types)
   recovery.c:238:    expected unsigned int [unsigned] ofs_in_node
   recovery.c:238:    got restricted __le16 [assigned] [usertype] ofs_in_node
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

It is possible that iput is skipped after iget during the recovery.

In recover_dentry(),
 dir = f2fs_iget();
 ...
 if (de && inode->i_ino == le32_to_cpu(de->ino))
	goto out;

In this case, this dir is not able to be added in dirty_dir_inode_list.
The actual linking is done only when set_page_dirty() is called.

So let's add this newly got inode into the list explicitly, and put it at the
end of the recovery routine.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

The error scenario is:
1. create /a
(1.a link /a /b)
2. sync
3. unlinke /a
4. create /a
5. fsync /a
6. Sudden power-off

When the f2fs recovers the fsynced dentry, /a, we discover an exsiting dentry at
f2fs_find_entry() in recover_dentry().

In such the case, we should unlink the existing dentry and its inode
and then recover newly created dentry.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

There is an error path where "dir" is an ERR_PTR.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This patch adds error handling codes of check_index_in_prev_nodes and its
caller, do_recover_data.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This patch fixes the following deadlock bug during the recovery.

INFO: task mount:1322 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
mount           D ffffffff81125870     0  1322   1266 0x00000000
 ffff8801207e39d8 0000000000000046 ffff88012ab1dee0 0000000000000046
 ffff8801207e3a08 ffff880115903f40 ffff8801207e3fd8 ffff8801207e3fd8
 ffff8801207e3fd8 ffff880115903f40 ffff8801207e39d8 ffff88012fc94520
Call Trace:
[<ffffffff81125870>] ? __lock_page+0x70/0x70
[<ffffffff816a92d9>] schedule+0x29/0x70
[<ffffffff816a93af>] io_schedule+0x8f/0xd0
[<ffffffff8112587e>] sleep_on_page+0xe/0x20
[<ffffffff816a649a>] __wait_on_bit_lock+0x5a/0xc0
[<ffffffff81125867>] __lock_page+0x67/0x70
[<ffffffff8106c7b0>] ? autoremove_wake_function+0x40/0x40
[<ffffffff81126857>] find_lock_page+0x67/0x80
[<ffffffff8112698f>] find_or_create_page+0x3f/0xb0
[<ffffffffa03901a8>] ? sync_inode_page+0xa8/0xd0 [f2fs]
[<ffffffffa038fdf7>] get_node_page+0x67/0x180 [f2fs]
[<ffffffffa039818b>] recover_fsync_data+0xacb/0xff0 [f2fs]
[<ffffffff816aaa1e>] ? _raw_spin_unlock+0x3e/0x40
[<ffffffffa0389634>] f2fs_fill_super+0x7d4/0x850 [f2fs]
[<ffffffff81184cf9>] mount_bdev+0x1c9/0x210
[<ffffffffa0388e60>] ? validate_superblock+0x180/0x180 [f2fs]
[<ffffffffa0387635>] f2fs_mount+0x15/0x20 [f2fs]
[<ffffffff81185a13>] mount_fs+0x43/0x1b0
[<ffffffff81145ba0>] ? __alloc_percpu+0x10/0x20
[<ffffffff811a0796>] vfs_kern_mount+0x76/0x120
[<ffffffff811a2cb7>] do_mount+0x237/0xa10
[<ffffffff81140b9b>] ? strndup_user+0x5b/0x80
[<ffffffff811a3520>] SyS_mount+0x90/0xe0
[<ffffffff816b3502>] system_call_fastpath+0x16/0x1b

The bug is triggered when check_index_in_prev_nodes tries to get the direct
node page by calling get_node_page.
At this point, if the direct node page is already locked by get_dnode_of_data,
its caller, we got a deadlock condition.

This patch adds additional condition check for the reuse of locked direct node
pages prior to the get_node_page call.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

If we met an error during the dentry recovery, we should not conduct checkpoint.
Otherwise, some errorneous dentry blocks overwrites the existing blocks that
contain the remaining recovery information.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

If we got an error after lock_page, we should unlock it before exit.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

The allocated page used by the recovery is not on HIGHMEM, so that we don't
need to use kmap/kunmap.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

This patch adds some trivial debugging messages in the recovery process.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

During the dentry recovery routine, recover_inode() triggers __f2fs_add_link
with its directory inode.

In the following scenario, a bug is captured.
 1. dir = f2fs_iget(pino)
 2. __f2fs_add_link(dir, name)
 3. iput(dir)
  -> f2fs_evict_inode() faces with BUG_ON(atomic_read(fi->dirty_dents))

Kernel BUG at ffffffffa01c0676 [verbose debug info unavailable]
[<ffffffffa01c0676>] f2fs_evict_inode+0x276/0x300 [f2fs]
Call Trace:
 [<ffffffff8118ea00>] evict+0xb0/0x1b0
 [<ffffffff8118f1c5>] iput+0x105/0x190
 [<ffffffffa01d2dac>] recover_fsync_data+0x3bc/0x1070 [f2fs]
 [<ffffffff81692e8a>] ? io_schedule+0xaa/0xd0
 [<ffffffff81690acb>] ? __wait_on_bit_lock+0x7b/0xc0
 [<ffffffff8111a0e7>] ? __lock_page+0x67/0x70
 [<ffffffff81165e21>] ? kmem_cache_alloc+0x31/0x140
 [<ffffffff8118a502>] ? __d_instantiate+0x92/0xf0
 [<ffffffff812a949b>] ? security_d_instantiate+0x1b/0x30
 [<ffffffff8118a5b4>] ? d_instantiate+0x54/0x70

This means that we should flush all the dentry pages between iget and iput().
But, during the recovery routine, it is unallowed due to consistency, so we
have to wait the whole recovery process.
And then, write_checkpoint flushes all the dirty dentry blocks, and nicely we
can put the stale dir inodes from the dirty_dir_inode_list.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>