`flags' is used to save value from userspace, there is no need to
initialize it, and FS_FL_USER_VISIBLE is the mask for getflags.
Signed-off-by: NSheng Yong <shengyong1@huawei.com>
Acked-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In available_free_memory, there are two same judgement conditions which
is used for checking NAT excess, remove one of them.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

During fstrim, if one of multiple write_checkpoint failed, break off and
return error number to caller.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

If we preallocate blocks with f2fs_reserve_blocks in f2fs_map_blocks, we
should call f2fs_balance_fs for checking and reclaiming space, fix it.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

When building each sit entry in cache, firstly, we will load it from
sit page, and then check all entries in sit journal, if there is one
updated entry in journal, cover cached entry with the journaled one.

Actually, most of check operation is unneeded since we only need
to update cached entries with journaled entries in batch, so
changing the flow as below for more efficient:
1. load all sit entries into cache from sit pages;
2. update sit entries with journal.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch changes to check valid block number of one GCed section
directly instead of checking the number in all segments of section
one by one in order to clean up codes of foreground GC.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

We don't guarantee integrity of user data after checkpoint, since we only
guarantee meta data integrity for data consistency of filesystem.

Due to above reason, we only need to set fs as dirty when meta data is
updated, so that we can skip writing checkpoint in some case of non-meta
data is updated.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch enables to do fstrim without checkpoint, if there is no fs
change.
Signed-off-by: NYunlei He <heyunlei@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch add discard block count to sys entry of f2fs status
Signed-off-by: NYunlei He <heyunlei@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This is to reduce the batch size of fstrim to avoid long latency.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

We don't need to keep discard_map, if disk does not support discard command.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

we came across an error as below:

[build_nat_area_bitmap:1710] nid[0x    1718] addr[0x         1c18ddc] ino[0x    1718]
[build_nat_area_bitmap:1710] nid[0x    1719] addr[0x         1c193d5] ino[0x    1719]
[build_nat_area_bitmap:1710] nid[0x    171a] addr[0x         1c1736e] ino[0x    171a]
[build_nat_area_bitmap:1710] nid[0x    171b] addr[0x        58b3ee8f] ino[0x815f92ed]
[build_nat_area_bitmap:1710] nid[0x    171c] addr[0x         fcdc94b] ino[0x49366377]
[build_nat_area_bitmap:1710] nid[0x    171d] addr[0x        7cd2facf] ino[0xb3c55300]
[build_nat_area_bitmap:1710] nid[0x    171e] addr[0x        bd4e25d0] ino[0x77c34c09]

... ...

[build_nat_area_bitmap:1710] nid[0x    1718] addr[0x         1c18ddc] ino[0x    1718]
[build_nat_area_bitmap:1710] nid[0x    1719] addr[0x         1c193d5] ino[0x    1719]
[build_nat_area_bitmap:1710] nid[0x    171a] addr[0x         1c1736e] ino[0x    171a]
[build_nat_area_bitmap:1710] nid[0x    171b] addr[0x        58b3ee8f] ino[0x815f92ed]
[build_nat_area_bitmap:1710] nid[0x    171c] addr[0x         fcdc94b] ino[0x49366377]
[build_nat_area_bitmap:1710] nid[0x    171d] addr[0x        7cd2facf] ino[0xb3c55300]
[build_nat_area_bitmap:1710] nid[0x    171e] addr[0x        bd4e25d0] ino[0x77c34c09]

One nat block may be stepped by a data block, so this patch forbid to
write if the blkaddr is illegal
Signed-off-by: NYunlei He <heyunlei@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Thread A			Thread B
- inode_lock fileA
				- inode_lock fileB
				 - inode_lock fileA
 - inode_lock fileB

We may encounter above potential deadlock during moving file range in
concurrent scenario. This patch fixes the issue by using inode_trylock
instead.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Only if two input files are regular files, we allow copying data in
range of them, otherwise, deny it.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This reverts commit a2ee0a30.

When testing with generic/032 of xfstest suit, failure message will be
reported as below:

generic/032 8s ... [failed, exit status 1] - output mismatch (see results/generic/032.out.bad)
    --- tests/generic/032.out	2015-01-11 16:52:27.643681072 +0800
    +++ results/generic/032.out.bad	2016-08-06 13:44:43.861330500 +0800
    @@ -1,5 +1,5 @@
     QA output created by 032
    -100 iterations
    -0000000 cdcd cdcd cdcd cdcd cdcd cdcd cdcd cdcd
    -*
    -0100000
    +1: [768..775]: unwritten
    +Unwritten extents found!
    ...
    (Run 'diff -u tests/generic/032.out results/generic/032.out.bad'  to see the entire diff)
Ran: generic/032
Failures: generic/032
Failed 1 of 1 tests

In write_end(), we should update i_size of inode before unlock page,
otherwise, we will lose newly updated data in following race condition.

Thread A			Thread B
- write_end
 - unlock page
				- writepages
				 - lock_page
				  - writepage
				  if page is out-of-range of file size,
				  we will skip writting the page.
 - update i_size
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

LKP reported -36.3% regression of fsmark.files_per_sec due to this patch.
I've confirmed that fxmark [1] has also slight regression for DWAL.

[1] https://github.com/sslab-gatech/fxmark

This reverts commit ec795418.

Merge 4fc29c1a included this extra line, but it's not needed (or
useful) since we'll bio_set_op_attrs() right after to properly set
the op and flags for the bio.
Signed-off-by: NJens Axboe <axboe@fb.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Vladimir has noticed that we might declare memcg oom even during
readahead because read_pages only uses GFP_KERNEL (with mapping_gfp
restriction) while __do_page_cache_readahead uses
page_cache_alloc_readahead which adds __GFP_NORETRY to prevent from
OOMs.  This gfp mask discrepancy is really unfortunate and easily
fixable.  Drop page_cache_alloc_readahead() which only has one user and
outsource the gfp_mask logic into readahead_gfp_mask and propagate this
mask from __do_page_cache_readahead down to read_pages.

This alone would have only very limited impact as most filesystems are
implementing ->readpages and the common implementation mpage_readpages
does GFP_KERNEL (with mapping_gfp restriction) again.  We can tell it to
use readahead_gfp_mask instead as this function is called only during
readahead as well.  The same applies to read_cache_pages.

ext4 has its own ext4_mpage_readpages but the path which has pages !=
NULL can use the same gfp mask.  Btrfs, cifs, f2fs and orangefs are
doing a very similar pattern to mpage_readpages so the same can be
applied to them as well.

[akpm@linux-foundation.org: coding-style fixes]
[mhocko@suse.com: restrict gfp mask in mpage_alloc]
  Link: http://lkml.kernel.org/r/20160610074223.GC32285@dhcp22.suse.cz
Link: http://lkml.kernel.org/r/1465301556-26431-1-git-send-email-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Cc: Chris Mason <clm@fb.com>
Cc: Steve French <sfrench@samba.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Jan Kara <jack@suse.cz>
Cc: Mike Marshall <hubcap@omnibond.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Changman Lee <cm224.lee@samsung.com>
Cc: Chao Yu <yuchao0@huawei.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch includes minor clean-ups.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Previous selected segment may become free after write_checkpoint,
if we do garbage collect on this segment, and then new_curseg happen
to reuse it, it may cause f2fs_bug_on as below.

	panic+0x154/0x29c
	do_garbage_collect+0x15c/0xaf4
	f2fs_gc+0x2dc/0x444
	f2fs_balance_fs.part.22+0xcc/0x14c
	f2fs_balance_fs+0x28/0x34
	f2fs_map_blocks+0x5ec/0x790
	f2fs_preallocate_blocks+0xe0/0x100
	f2fs_file_write_iter+0x64/0x11c
	new_sync_write+0xac/0x11c
	vfs_write+0x144/0x1e4
	SyS_write+0x60/0xc0

Here, maybe we check sit and ssa type during reset_curseg. So, we check
segment is stale or not, and select a new victim to avoid this.
Signed-off-by: NYunlei He <heyunlei@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

These two are confusing leftover of the old world order, combining
values of the REQ_OP_ and REQ_ namespaces.  For callers that don't
special case we mostly just replace bi_rw with bio_data_dir or
op_is_write, except for the few cases where a switch over the REQ_OP_
values makes more sense.  Any check for READA is replaced with an
explicit check for REQ_RAHEAD.  Also remove the READA alias for
REQ_RAHEAD.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NMike Christie <mchristi@redhat.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

It's enough to show BUG or WARN by f2fs_bug_on for error case.
Then, we don't need to remain corrupted filesystem.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

When fs utilization is almost full, f2fs_sync_file should do checkpoint if
there is not enough space for roll-forward later. (i.e. space_for_roll_forward)
So, currently we have no lock for sbi->alloc_valid_block_count, resulting in
race condition.

In rare case, we can get -ENOSPC when doing roll-forward which triggers

	if (is_valid_blkaddr(sbi, dest, META_POR)) {
		if (src == NULL_ADDR) {
			err = reserve_new_block(&dn);
			f2fs_bug_on(sbi, err);
			...
		}
		...
	}
in do_recover_data.

So, this patch avoids that situation in advance.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch implements moving a range of data blocks from source file to
destination file.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch fixes to report the right error number of f2fs_find_entry to
its caller.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

We need to avoid ENOMEM due to unexpected long length.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

The default value of idle interval is 2 mins, but for most time when
screen shutdown, there are still operations during the 2 mins interval,
and gc's sleep time is about 30 secs to 60 secs, so there is almost no
chance for GC thread to do garbage collecting.

Set default value of idle interval value from 2 mins to 5 secs for
fixing.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch reverts 19a5f5e2 (f2fs: drop any block plugging),
and adds blk_plug in write paths additionally.

The main reason is that blk_start_plug can be used to wake up from low-power
mode before submitting further bios.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Datas in file can be operated by GC and DIO simultaneously, so we will
face race case as below:

For write case:
Thread A				Thread B
- generic_file_direct_write
 - invalidate_inode_pages2_range
 - f2fs_direct_IO
  - do_blockdev_direct_IO
   - do_direct_IO
    - get_more_blocks
					- f2fs_gc
					 - do_garbage_collect
					  - gc_data_segment
					   - move_data_page
					    - do_write_data_page
					    migrate data block to new block address
   - dio_bio_submit
   update user data to old block address

For read case:
Thread A                                Thread B
- generic_file_direct_write
 - invalidate_inode_pages2_range
 - f2fs_direct_IO
  - do_blockdev_direct_IO
   - do_direct_IO
    - get_more_blocks
					- f2fs_balance_fs
					 - f2fs_gc
					  - do_garbage_collect
					   - gc_data_segment
					    - move_data_page
					     - do_write_data_page
					     migrate data block to new block address
					  - write_checkpoint
					   - do_checkpoint
					    - clear_prefree_segments
					     - f2fs_issue_discard
                                             discard old block adress
   - dio_bio_submit
   update user buffer from obsolete block address

In order to fix this, for one file, we should let DIO and GC getting exclusion
against with each other.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In 1TB storage, we need to admit 22841 prefree segments, which can consume
too much segments.
This patch sets 8GB in max. prefree segments in that case.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This reduces the elapsed time to do xfstests/generic/017.

Before: 458 s
After:  390 s
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This reduces the elapsed time to do xfstests/generic/017.

Before: 715 s
After:  458 s
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This is to fix wrong error pointer handling flow reported by Dan.
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NChao Yu <chao@kernel.org>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Let's check inode's dirtiness before calling mark_inode_dirty.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

We don't need to do i_size_write under page lock.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

With below test steps, f2fs will issue redundant discard when doing fstrim,
the reason is that we issue discards for both prefree segments and
consecutive freed region user wants to trim, part regions they covered are
overlapped, here, we change to do not to issue any discards for prefree
segments in trimmed range.

1. mount -t f2fs -o discard /dev/zram0 /mnt/f2fs
2. fstrim -o 0 -l 3221225472 -m 2097152 -v /mnt/f2fs/
3. dd if=/dev/zero  of=/mnt/f2fs/a bs=2M count=1
4. dd if=/dev/zero  of=/mnt/f2fs/b bs=1M count=1
5. sync
6. rm /mnt/f2fs/a /mnt/f2fs/b
7. fstrim -o 0 -l 3221225472 -m 2097152 -v /mnt/f2fs/

Before:
<...>-5428  [001] ...1  9511.052125: f2fs_issue_discard: dev = (251,0), blkstart = 0x2200, blklen = 0x200
<...>-5428  [001] ...1  9511.052787: f2fs_issue_discard: dev = (251,0), blkstart = 0x2200, blklen = 0x300

After:
<...>-6764  [000] ...1  9720.382504: f2fs_issue_discard: dev = (251,0), blkstart = 0x2200, blklen = 0x300
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch skip discard block range smaller than trim_minlen,
and can not be merged by neighbour
Signed-off-by: NYunlei He <heyunlei@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

As manual described, f_bfree indicates total free blocks in fs, in f2fs, it
includes two parts: visible free blocks and over-provision blocks. This
patch corrrects the calculation.

fsblkcnt_t   f_bfree;   /* free blocks in fs */
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch replaces rw_semaphore with percpu_rw_semaphore for:
sbi->cp_rwsem
nm_i->nat_tree_lock
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>