A deadlock can be occurred:
Thread 1]                             Thread 2]
 - f2fs_write_data_pages              - f2fs_write_begin
   - lock_page(page #0)
                                        - grab_cache_page(page #X)
                                        - get_node_page(inode_page)
                                        - grab_cache_page(page #0)
                                          : to convert inline_data
   - f2fs_write_data_page
     - f2fs_write_inline_data
       - get_node_page(inode_page)

In this case, trying to lock inode_page and page #0 causes deadlock.
In order to avoid this, this patch adds a rule for this locking policy,
which is that page #0 should be locked followed by inode_page lock.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Two jump labels were adjusted in the implementation of the
create_node_manager_caches() function because these identifiers
contained typos.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

In f2fs_evict_inode,
 commit_inmemory_pages
   f2fs_gc
     f2fs_iget
       iget_locked
         -> wait for inode free

Here, if the inode is same as the one to be evicted, f2fs should wait forever.
Actually, we should not call f2fs_balance_fs during f2fs_evict_inode to avoid
this.

But, the commit_inmem_pages calls f2fs_balance_fs by default, even if
f2fs_evict_inode wants to free inmemory pages only.

Hence, this patch adds to trigger f2fs_balance_fs only when there is something
to write.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

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

It used nat_entry_set when create slab for sit_entry_set.
Signed-off-by: Changman Lee <cm224.lee@samsung.com>
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Whenever f2fs updates mapped pages, it needs to call flush_dcache_page.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Under memory pressure, we don't need to skip SSA page writes.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

If a node page is request to be written during the reclaiming path, we should
submit the bio to avoid pending to recliam it.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Now in f2fs, we have three inode cache: ORPHAN_INO, APPEND_INO, UPDATE_INO,
and we manage fields related to inode cache separately in struct f2fs_sb_info
for each inode cache type.
This makes codes a bit messy, so that this patch intorduce a new struct
inode_management to wrap inner fields as following which make codes more neat.

/* for inner inode cache management */
struct inode_management {
	struct radix_tree_root ino_root;	/* ino entry array */
	spinlock_t ino_lock;			/* for ino entry lock */
	struct list_head ino_list;		/* inode list head */
	unsigned long ino_num;			/* number of entries */
};

struct f2fs_sb_info {
	...
	struct inode_management im[MAX_INO_ENTRY];      /* manage inode cache */
	...
}
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Because we have checked the contrary condition in case of "if" judgment, we do
not need to check the condition again in case of "else" judgment. Let's remove
it.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

In f2fs_remount, we will stop gc thread and set need_restart_gc as true when new
option is set without BG_GC, then if any error occurred in the following
procedure, we can restore to start the gc thread.
But after that, We will fail to restore gc thread in start_gc_thread as BG_GC is
not set in new option, so we'd better move this condition judgment out of
start_gc_thread to fix this issue.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

We should put the inode page when error was occurred.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

The locked page should be released before returning the function.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

If i_size becomes large outside of MAX_INLINE_DATA, we shoud convert the inode.
Otherwise, we can make some dirty pages during the truncation, and those pages
will be written through f2fs_write_data_page.
At that moment, the inode has still inline_data, so that it tries to write non-
zero pages into inline_data area.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

The scenario is like this.

One trhead triggers:
  f2fs_write_data_pages
    lock_page
    f2fs_write_data_page
      f2fs_lock_op  <- wait

The other thread triggers:
  f2fs_truncate
    truncate_blocks
      f2fs_lock_op
        truncate_partial_data_page
          lock_page  <- wait for locking the page

This patch resolves this bug by relocating truncate_partial_data_page.
This function is just to truncate user data page and not related to FS
consistency as well.
And, we don't need to call truncate_inline_data. Rather than that,
f2fs_write_data_page will finally update inline_data later.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

The # of inline_data inode is decreased only when it has inline_data.
After clearing the flag, we can't decreased the number.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

If a mount option has dirsync, we should call checkpoint for all the directory
operations.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Under memory pressure, let's avoid skipping data writes.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

It needs to write node pages if checkpoint is not doing in order to avoid
memory pressure.
Reviewed-by: Changman Lee <cm224.lee@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch adds to control the memory footprint used by ino entries.
This will conduct best effort, not strictly.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch adds to monitor the number of ino entries.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

The roll-forward mechanism should be activated when the number of active
logs is not 2.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

If a system wants to reduce the booting time as a top priority, now we can
use a mount option, -o fastboot.
With this option, f2fs conducts a little bit slow write_checkpoint, but
it can avoid the node page reads during the next mount time.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Let's remove unused macro.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

__submit_merged_bio    f2fs_write_end_io        f2fs_write_end_io
                       wait_io = X              wait_io = x
                       complete(X)              complete(X)
                       wait_io = NULL
wait_for_completion()
free(X)
                                                 spin_lock(X)
                                                 kernel panic

In order to avoid this, this patch removes the wait_io facility.
Instead, we can use wait_on_all_pages_writeback(sbi) to wait for end_ios.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

If there is a chance to make a huge sized discard command, we don't need
to split it out, since each blkdev_issue_discard should wait one at a
time.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch simplifies the inline_data usage with the following rule.
1. inline_data is set during the file creation.
2. If new data is requested to be written ranges out of inline_data,
 f2fs converts that inode permanently.
3. There is no cases which converts non-inline_data inode to inline_data.
4. The inline_data flag should be changed under inode page lock.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

There's no point in using test_and_clear_bit_le() when we don't use the
return value of the function. Just use clear_bit_le() instead.

Coverity-id: 1016434
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

We should not discard any data protected by the previous checkpoint all
the time.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

When reading inline data, we should call flush_dcache_page.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

During the write_checkpoint, we should avoid f2fs_gc trigger to avoid any
filesystem consistency.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs_write_begin() doesn't initialize the 'dn' variable if the inode has
inline data. However it uses its contents to decide whether it should
just zero out the page or load data to it. Thus if we are unlucky we can
zero out page contents instead of loading inline data into a page.

CC: stable@vger.kernel.org
CC: Changman Lee <cm224.lee@samsung.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Rename f2fs_set/clear_bit to f2fs_test_and_set/clear_bit, which mean
set/clear bit and return the old value, for better readability.
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Set raw_super default to NULL to avoid the possibly used
uninitialized warning, though we may never hit it in fact.
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Introduce f2fs_change_bit to simplify the change bit logic in
function set_to_next_nat{sit}.
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Use clear_inode_flag to replace the redundant cond_clear_inode_flag.
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Remove the unneeded argument 'type' from __get_victim, use
NO_CHECK_TYPE directly when calling v_ops->get_victim().
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

If user specifies too low end sector for trimming, f2fs_trim_fs() will
use uninitialized value as a number of trimmed blocks and returns it to
userspace. Initialize number of trimmed blocks early to avoid the
problem.

Coverity-id: 1248809
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch declares f2fs_convert_inline_dir as a static function, which was
reported by kbuild test robot.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>