As Ted reported:

"Hi, I was looking at f2fs's sources recently, and I noticed that there
is a very large number of non-static symbols which don't have a f2fs
prefix.  There's well over a hundred (see attached below).

As one example, in fs/f2fs/dir.c there is:

unsigned char get_de_type(struct f2fs_dir_entry *de)

This function is clearly only useful for f2fs, but it has a generic
name.  This means that if any other file system tries to have the same
symbol name, there will be a symbol conflict and the kernel would not
successfully build.  It also means that when someone is looking f2fs
sources, it's not at all obvious whether a function such as
read_data_page(), invalidate_blocks(), is a generic kernel function
found in the fs, mm, or block layers, or a f2fs specific function.

You might want to fix this at some point.  Hopefully Kent's bcachefs
isn't similarly using genericly named functions, since that might
cause conflicts with f2fs's functions --- but just as this would be a
problem that we would rightly insist that Kent fix, this is something
that we should have rightly insisted that f2fs should have fixed
before it was integrated into the mainline kernel.

acquire_orphan_inode
add_ino_entry
add_orphan_inode
allocate_data_block
allocate_new_segments
alloc_nid
alloc_nid_done
alloc_nid_failed
available_free_memory
...."

This patch adds "f2fs_" prefix for all non-static symbols in order to:
a) avoid conflict with other kernel generic symbols;
b) to indicate the function is f2fs specific one instead of generic
one;
Reported-by: NTheodore Ts'o <tytso@mit.edu>
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Introduce clear_radix_tree_dirty_tag to include common codes for cleanup.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

- rename is_valid_blkaddr() to is_valid_meta_blkaddr() for readability.
- introduce is_valid_blkaddr() for cleanup.

No logic change in this patch.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

We still provide readdir() after shtudown, so we should keep pages to avoid
additional IOs.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

syzbot hit the following crash on upstream commit
83beed7b (Fri Apr 20 17:56:32 2018 +0000)
Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux-soc-thermal
syzbot dashboard link: https://syzkaller.appspot.com/bug?extid=d154ec99402c6f628887

C reproducer: https://syzkaller.appspot.com/x/repro.c?id=5414336294027264
syzkaller reproducer: https://syzkaller.appspot.com/x/repro.syz?id=5471683234234368
Raw console output: https://syzkaller.appspot.com/x/log.txt?id=5436660795834368
Kernel config: https://syzkaller.appspot.com/x/.config?id=1808800213120130118
compiler: gcc (GCC) 8.0.1 20180413 (experimental)

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+d154ec99402c6f628887@syzkaller.appspotmail.com
It will help syzbot understand when the bug is fixed. See footer for details.
If you forward the report, please keep this part and the footer.

F2FS-fs (loop0): Magic Mismatch, valid(0xf2f52010) - read(0x0)
F2FS-fs (loop0): Can't find valid F2FS filesystem in 1th superblock
F2FS-fs (loop0): invalid crc value
------------[ cut here ]------------
kernel BUG at fs/f2fs/node.c:1185!
invalid opcode: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 4549 Comm: syzkaller704305 Not tainted 4.17.0-rc1+ #10
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__get_node_page+0xb68/0x16e0 fs/f2fs/node.c:1185
RSP: 0018:ffff8801d960e820 EFLAGS: 00010293
RAX: ffff8801d88205c0 RBX: 0000000000000003 RCX: ffffffff82f6cc06
RDX: 0000000000000000 RSI: ffffffff82f6d5e8 RDI: 0000000000000004
RBP: ffff8801d960ec30 R08: ffff8801d88205c0 R09: ffffed003b5e46c2
R10: 0000000000000003 R11: 0000000000000003 R12: ffff8801a86e00c0
R13: 0000000000000001 R14: ffff8801a86e0530 R15: ffff8801d9745240
FS:  000000000072c880(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3d403209b8 CR3: 00000001d8f3f000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 get_node_page fs/f2fs/node.c:1237 [inline]
 truncate_xattr_node+0x152/0x2e0 fs/f2fs/node.c:1014
 remove_inode_page+0x200/0xaf0 fs/f2fs/node.c:1039
 f2fs_evict_inode+0xe86/0x1710 fs/f2fs/inode.c:547
 evict+0x4a6/0x960 fs/inode.c:557
 iput_final fs/inode.c:1519 [inline]
 iput+0x62d/0xa80 fs/inode.c:1545
 f2fs_fill_super+0x5f4e/0x7bf0 fs/f2fs/super.c:2849
 mount_bdev+0x30c/0x3e0 fs/super.c:1164
 f2fs_mount+0x34/0x40 fs/f2fs/super.c:3020
 mount_fs+0xae/0x328 fs/super.c:1267
 vfs_kern_mount.part.34+0xd4/0x4d0 fs/namespace.c:1037
 vfs_kern_mount fs/namespace.c:1027 [inline]
 do_new_mount fs/namespace.c:2518 [inline]
 do_mount+0x564/0x3070 fs/namespace.c:2848
 ksys_mount+0x12d/0x140 fs/namespace.c:3064
 __do_sys_mount fs/namespace.c:3078 [inline]
 __se_sys_mount fs/namespace.c:3075 [inline]
 __x64_sys_mount+0xbe/0x150 fs/namespace.c:3075
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x443dea
RSP: 002b:00007ffcc7882368 EFLAGS: 00000297 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000020000c00 RCX: 0000000000443dea
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007ffcc7882370
RBP: 0000000000000003 R08: 0000000020016a00 R09: 000000000000000a
R10: 0000000000000000 R11: 0000000000000297 R12: 0000000000000004
R13: 0000000000402ce0 R14: 0000000000000000 R15: 0000000000000000
RIP: __get_node_page+0xb68/0x16e0 fs/f2fs/node.c:1185 RSP: ffff8801d960e820
---[ end trace 4edbeb71f002bb76 ]---

Reported-and-tested-by: syzbot+d154ec99402c6f628887@syzkaller.appspotmail.com
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch clears PageError in some pages tagged by read path, but when we
write the pages with valid contents, writepage should clear the bit likewise
ext4.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch reverts copied f2fs_set_page_dirty_nobuffer to use generic function
for stability.

This reverts commit fe76b796.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Remove the address_space ->tree_lock and use the xa_lock newly added to
the radix_tree_root.  Rename the address_space ->page_tree to ->i_pages,
since we don't really care that it's a tree.

[willy@infradead.org: fix nds32, fs/dax.c]
  Link: http://lkml.kernel.org/r/20180406145415.GB20605@bombadil.infradead.orgLink: http://lkml.kernel.org/r/20180313132639.17387-9-willy@infradead.orgSigned-off-by: NMatthew Wilcox <mawilcox@microsoft.com>
Acked-by: NJeff Layton <jlayton@redhat.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Nat entry set is used only in checkpoint(), and during checkpoint() we
won't flush new nat entry with unallocated address, so we don't need to
add new nat entry into nat set, then nat_entry_set::entry_cnt can
indicate actual entry count we need to flush in checkpoint().
Signed-off-by: NYunlei He <heyunlei@huawei.com>
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Clean up F2FS_BYTES_TO_BLK(x + F2FS_BLKSIZE - 1) with F2FS_BLK_ALIGN(x).
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

For example, in arm64, free_nid_bitmap should be aligned to word size in order
to use bit operations.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

When setting COLD_BIT_SHIFT flag in node block, we only need to call
set_cold_node() in new_node_page() and recover_inode_page() during
node page initialization. So remove unneeded set_cold_node() in other
places.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Clean up codes with GFP_F2FS_ZERO, no logic changes.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Don't remain dirtied page cache in f2fs after shutdown, it can mitigate
memory pressure of whole system, in order to keep other modules working
properly.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Cgroup writeback requires explicit support from the filesystem.
f2fs's data and node writeback IOs go through __write_data_page,
which sets fio for submiting IOs. So, we add io_wbc for fio,
associate bios with blkcg by invoking wbc_init_bio() and
account IOs issuing by wbc_account_io().
In addtion, f2fs_fill_super() is updated to set SB_I_CGROUPWB.

Meta writeback IOs is left alone by this patch and will always be
attributed to the root cgroup.

The results show that f2fs can throttle writeback nicely for
data writing and file creating.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NYufen Yu <yuyufen@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

After checkpoint,
 1. creat a new file A ,(with dirty inode && dirty inode page && xattr info)
 2. backgroud wb write back file A inode page (without update from inode cache)
 3. fsync file A, write back inode page of file A with inode cache info
 4. sudden power off before new checkpoint

In this case, recovery process will try to recover a zero inode
page. Inline xattr flag of file A will be miss and xattr info
will be taken as blkaddr index.
Signed-off-by: NYunlei He <heyunlei@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

No need return value in restore summary process
Signed-off-by: NYunlei He <heyunlei@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch supports to inject fault into kvmalloc/kvzalloc.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch introduces f2fs_kzalloc based on f2fs_kmalloc in order to
support error injection for kzalloc().
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

f2fs: remove repeated f2fs_bug_on which has already existed
      in function invalidate_blocks.
Signed-off-by: NZhikang Zhang <zhangzhikang1@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Commit d260081c ("f2fs: change recovery policy of xattr node block")
removes the use of blkaddr, which is no longer used. So remove the
parameter.
Signed-off-by: NSheng Yong <shengyong1@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

alloc_nid_failed and scan_nat_page can be called at the same time,
and we haven't protected add_free_nid and update_free_nid_bitmap
with the same nid_list_lock. That could lead to

Thread A				Thread B
- __build_free_nids
 - scan_nat_page
  - add_free_nid
					- alloc_nid_failed
					 - update_free_nid_bitmap
  - update_free_nid_bitmap

scan_nat_page will clear the free bitmap since the nid is PREALLOC_NID,
but alloc_nid_failed needs to set the free bitmap. This results in
free nid with free bitmap cleared.
This patch update the bitmap under the same nid_list_lock in add_free_nid.
And use __GFP_NOFAIL to make sure to update status of free nid correctly.
Signed-off-by: NFan li <fanofcode.li@samsung.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

No need to read nat block if nat_block_bitmap is set.
Signed-off-by: NYunlei He <heyunlei@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

During mkfs, quota sysfiles have already occupied nid resource,
it needs to adjust remaining available nid count in kernel side.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Every pagevec_init user claims the pages being released are hot even in
cases where it is unlikely the pages are hot.  As no one cares about the
hotness of pages being released to the allocator, just ditch the
parameter.

No performance impact is expected as the overhead is marginal.  The
parameter is removed simply because it is a bit stupid to have a useless
parameter copied everywhere.

Link: http://lkml.kernel.org/r/20171018075952.10627-6-mgorman@techsingularity.netSigned-off-by: NMel Gorman <mgorman@techsingularity.net>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

All users of pagevec_lookup() and pagevec_lookup_range() now pass
PAGEVEC_SIZE as a desired number of pages.  Just drop the argument.

Link: http://lkml.kernel.org/r/20171009151359.31984-15-jack@suse.czSigned-off-by: NJan Kara <jack@suse.cz>
Reviewed-by: NDaniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In several places we want to iterate over all tagged pages in a mapping.
However the code was apparently copied from places that iterate only
over a limited range and thus it checks for index <= end, optimizes the
case where we are coming close to range end which is all pointless when
end == ULONG_MAX.  So just remove this dead code.

[akpm@linux-foundation.org: fix warnings]
Link: http://lkml.kernel.org/r/20171009151359.31984-7-jack@suse.czSigned-off-by: NJan Kara <jack@suse.cz>
Reviewed-by: NDaniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch splits memory allocation part in nat_entry to avoid lock contention.
Signed-off-by: NYunlei He <heyunlei@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In flush_nat_entries, all dirty nats will be flushed and if
their new address isn't NULL_ADDR, their bitmaps will be updated,
the free_nid_count of the bitmaps will be increaced regardless
of whether the nats have already been occupied before.
This could lead to wrong free_nid_count.
So this patch checks the status of the bits beforeactually
set/clear them.

Fixes: 586d1492 ("f2fs: skip scanning free nid bitmap of full NAT blocks")
Signed-off-by: NFan li <fanofcode.li@samsung.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Commit 4ac91242 ("f2fs: introduce free nid bitmap") copied codes
from __build_free_nids() into scan_free_nid_bits(), they are redundant,
introduce one common function scan_curseg_cache for cleanup.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

We call scan_free_nid_bits only when there isn't many
free nids left, it means that marked bits in free_nid_bitmap
are supposed to be few, use find_next_bit_le is more
efficient in such case.
According to my tests, use find_next_bit_le instead of
test_bit_le will cut down the traversal time to one
third of its original.
Signed-off-by: NFan li <fanofcode.li@samsung.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In current version, after scan_free_nid_bits, the scan is over if
nid_cnt[FREE_NID] != 0. In most cases, there are still free nids in the
free list during the scan, and scan_free_nid_bits usually can't increase
nid_cnt[FREE_NID]. It causes that __build_free_nids is called many times
without solving the shortage of the free nids. This patch fixes that.
Signed-off-by: NFan li <fanofcode.li@samsung.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Use a slightly easier way to calculate last_nid.
Signed-off-by: NFan li <fanofcode.li@samsung.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Make three modification for __update_nat_bits:
1. Take the codes of dealing the nat with nid 0 out of the loop
    Such nat only needs to be dealt with once at beginning.
2. Use " nat_index == 0" instead of " start_nid == 0" to decide if it's the first nat block
    It's better that we don't assume @start_nid is the first nid of the nat block it's in.
3. Use " if (nat_blk->entries[i].block_addr != NULL_ADDR)" to explicitly comfirm the value of block_addr
    use constant to make sure the codes is right, even if the value of NULL_ADDR changes.
Signed-off-by: NFan li <fanofcode.li@samsung.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

modify for accurate fggc node io stat
Signed-off-by: NYunlei He <heyunlei@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch add a new function to move nid from one state to another.
Move operation is heavily used, by adding a new function for it
we can cut down some branches from several flow.
Signed-off-by: NFan li <fanofcode.li@samsung.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds to support get_page error injection to simulate
out-of-memory test scenario.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Now, in product, more and more features based on file encryption were
introduced, their demand of xattr space is increasing, however, inline
xattr has fixed-size of 200 bytes, once inline xattr space is full, new
increased xattr data would occupy additional xattr block which may bring
us more space usage and performance regression during persisting.

In order to resolve above issue, it's better to expand inline xattr size
flexibly according to user's requirement.

So this patch introduces new filesystem feature 'flexible inline xattr',
and new mount option 'inline_xattr_size=%u', once mkfs enables the
feature, we can use the option to make f2fs supporting flexible inline
xattr size.

To support this feature, we add extra attribute i_inline_xattr_size in
inode layout, indicating that how many space inline xattr borrows from
block address mapping space in inode layout, by this, we can easily
locate and store flexible-sized inline xattr data in inode.

Inode disk layout:
  +----------------------+
  | .i_mode              |
  | ...                  |
  | .i_ext               |
  +----------------------+
  | .i_extra_isize       |
  | .i_inline_xattr_size |-----------+
  | ...                  |           |
  +----------------------+           |
  | .i_addr              |           |
  |  - block address or  |           |
  |  - inline data       |           |
  +----------------------+<---+      v
  |    inline xattr      |    +---inline xattr range
  +----------------------+<---+
  | .i_nid               |
  +----------------------+
  |   node_footer        |
  | (nid, ino, offset)   |
  +----------------------+

Note that, we have to cnosider backward compatibility which reserved
inline_data space, 200 bytes, all the time, reported by Sheng Yong.

Previous inline data or directory always reserved 200 bytes in inode layout,
even if inline_xattr is disabled. In order to keep inline_dentry's structure
for backward compatibility, we get the space back only from inline_data.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Reported-by: NSheng Yong <shengyong1@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch removes obosolete parameter for truncate_xattr_node.
Suggested-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

If some abnormal users try lots of atomic write operations, f2fs is able to
produce pinned pages in the main memory which affects system performance.
This patch limits that as 20% over total memory size, and if f2fs reaches
to the limit, it will drop all the inmemory pages.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>