Patch series "kvmalloc", v5.

There are many open coded kmalloc with vmalloc fallback instances in the
tree.  Most of them are not careful enough or simply do not care about
the underlying semantic of the kmalloc/page allocator which means that
a) some vmalloc fallbacks are basically unreachable because the kmalloc
part will keep retrying until it succeeds b) the page allocator can
invoke a really disruptive steps like the OOM killer to move forward
which doesn't sound appropriate when we consider that the vmalloc
fallback is available.

As it can be seen implementing kvmalloc requires quite an intimate
knowledge if the page allocator and the memory reclaim internals which
strongly suggests that a helper should be implemented in the memory
subsystem proper.

Most callers, I could find, have been converted to use the helper
instead.  This is patch 6.  There are some more relying on __GFP_REPEAT
in the networking stack which I have converted as well and Eric Dumazet
was not opposed [2] to convert them as well.

[1] http://lkml.kernel.org/r/20170130094940.13546-1-mhocko@kernel.org
[2] http://lkml.kernel.org/r/1485273626.16328.301.camel@edumazet-glaptop3.roam.corp.google.com

This patch (of 9):

Using kmalloc with the vmalloc fallback for larger allocations is a
common pattern in the kernel code.  Yet we do not have any common helper
for that and so users have invented their own helpers.  Some of them are
really creative when doing so.  Let's just add kv[mz]alloc and make sure
it is implemented properly.  This implementation makes sure to not make
a large memory pressure for > PAGE_SZE requests (__GFP_NORETRY) and also
to not warn about allocation failures.  This also rules out the OOM
killer as the vmalloc is a more approapriate fallback than a disruptive
user visible action.

This patch also changes some existing users and removes helpers which
are specific for them.  In some cases this is not possible (e.g.
ext4_kvmalloc, libcfs_kvzalloc) because those seems to be broken and
require GFP_NO{FS,IO} context which is not vmalloc compatible in general
(note that the page table allocation is GFP_KERNEL).  Those need to be
fixed separately.

While we are at it, document that __vmalloc{_node} about unsupported gfp
mask because there seems to be a lot of confusion out there.
kvmalloc_node will warn about GFP_KERNEL incompatible (which are not
superset) flags to catch new abusers.  Existing ones would have to die
slowly.

[sfr@canb.auug.org.au: f2fs fixup]
  Link: http://lkml.kernel.org/r/20170320163735.332e64b7@canb.auug.org.au
Link: http://lkml.kernel.org/r/20170306103032.2540-2-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com>
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>	[ext4 part]
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch fixes that SSR can overwrite previous warm node block consisting of
a node chain since the last checkpoint.

Fixes: 5b6c6be2 ("f2fs: use SSR for warm node as well")
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

If segs_per_sec is over 1 like under SMR, previously f2fs issues discard
commands redundantly on the same section, since we didn't move end position
for the previous discard command.

E.g.,

                       start  end
                         |    |
      prefree_bitmap = [01111100111100]

And, after issue discard for this section,
                             end      start
                              |        |
      prefree_bitmap = [01111100111100]

Select this section again by searching from (end + 1),
                             start  end
                                |   |
      prefree_bitmap = [01111100111100]

Fixes: 36abef4e ("f2fs: introduce mode=lfs mount option")
Cc: <stable@vger.kernel.org>
Cc: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In SSR mode, we can allocate target segment which has different
temperature type from the type of current block, in order to avoid
mixing coldest and hottest data/node as much as possible, change
SSR allocation policy to select closer temperature for current
block prior.
Signed-off-by: NYunlong Song <yunlong.song@huawei.com>
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Previously kernel message can show that in which function we do the
injection, but unfortunately, most of the caller are the same, for
tracking more information of injection path, it needs to show upper
caller's name. This patch supports that ability.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patches adds bitmaps to represent empty or full NAT blocks containing
free nid entries.

If we can find valid crc|cp_ver in the last block of checkpoint pack, we'll
use these bitmaps when building free nids. In order to avoid checkpointing
burden, up-to-date bitmaps will be flushed only during umount time. So,
normally we can get this gain, but when power-cut happens, we rely on fsck.f2fs
which recovers this bitmap again.

After this patch, we build free nids from nid #0 at mount time to make more
full NAT blocks, but in runtime, we check empty NAT blocks to load free nids
without loading any NAT pages from disk.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

For converntional zones, we don't need to align discard commands to exact zone
size.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

We don't need to wait for each discard commands when unmounting the image.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds MAX_DISCARD_BLOCKS() to avoid issuing too much large single
discard command.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch gives more SSR chances for node blocks.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Previously, if type is CURSEG_HOT_DATA, we only check CURSEG_HOT_DATA only.
This patch fixes to search all the different types for SSR.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Let's check SSR in prior to LFS allocation.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In allocate_segment_by_default(), need_SSR() already detected it's time to do
SSR. So, let's try to find victims for data segments more aggressively in time.
Signed-off-by: NYunlong Song <yunlong.song@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

SIT information should be updated before segment allocation, since SSR needs
latest valid block information. Current code does not update the old_blkaddr
info in sit_entry, so adjust the allocate_segment to its proper location. Commit
5e443818 ("f2fs: handle dirty segments inside
refresh_sit_entry") puts it into wrong location.
Signed-off-by: NYunlong Song <yunlong.song@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch shows actual device information in the tracepoints.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

We have had node chains, but haven't used it so far due to stale node blocks.
Now, we have crc|cp_ver in node footer and give random cp_ver at format time,
we can start to use it again.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

If the cached bio has the last page's index, then we need to submit it.
Otherwise, we don't need to submit it and can wait for further IO merges.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch moves the tracepoint location for flush command.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

We missed two functions declared as static functions.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

We only allocate flush merge control structure sbi::sm_info::fcc_info when
flush_merge option is on, but in f2fs_issue_flush we still try to access
member of the control structure without that option, it incurs panic as
show below, fix it.

Call Trace:
 __remove_ino_entry+0xa9/0xc0 [f2fs]
 f2fs_do_sync_file.isra.27+0x214/0x6d0 [f2fs]
 f2fs_sync_file+0x18/0x20 [f2fs]
 vfs_fsync_range+0x3d/0xb0
 __do_page_fault+0x261/0x4d0
 do_fsync+0x3d/0x70
 SyS_fsync+0x10/0x20
 do_syscall_64+0x6e/0x180
 entry_SYSCALL64_slow_path+0x25/0x25
RIP: 0033:0x7f18ce260de0
RSP: 002b:00007ffdd4589258 EFLAGS: 00000246 ORIG_RAX: 000000000000004a
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f18ce260de0
RDX: 0000000000000006 RSI: 00000000016c0360 RDI: 0000000000000003
RBP: 00000000016c0360 R08: 000000000000ffff R09: 000000000000001f
R10: 00007ffdd4589020 R11: 0000000000000246 R12: 00000000016c0100
R13: 0000000000000000 R14: 00000000016c1f00 R15: 00000000016c0100
Code: fb 81 e3 00 08 00 00 48 89 45 a0 0f 1f 44 00 00 31 c0 85 db 75 27 41 81 e7 00 04 00 00 74 0c 41 8b 45 20 85 c0 0f 85 81 00 00 00 <f0> 41 ff 45 20 4c 89 e7 e8 f8 e9 ff ff f0 41 ff 4d 20 48 83 c4
RIP: f2fs_issue_flush+0x5b/0x170 [f2fs] RSP: ffffc90003b5fd78
CR2: 0000000000000020
---[ end trace a09314c24f037648 ]---
Reported-by: NShuoran Liu <liushuoran@huawei.com>
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds stat information for flush and discard commands.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds a kernel thread to issue discard commands.
It proposes three states, D_PREP, D_SUBMIT, and D_DONE to identify current
bio status.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds discard_cmd_control with the existing discarding controls.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch simply cleans up the names for flush/discard commands.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds a mirror for sit version bitmap, and use it to detect
in-memory bitmap corruption which may be caused by bit-transition of
cache or memory overflow.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds a mirror for valid block bitmap, and use it to detect
in-memory bitmap corruption which may be caused by bit-transition of
cache or memory overflow.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch introduces a new flag to indicate inode status of doing atomic
write committing, so that, we can keep atomic write status for inode
during atomic committing, then we can skip GCing pages of atomic write inode,
that avoids random GCed datas being mixed with current transaction, so
isolation of transaction can be kept.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

If there is no candidate to submit discard command during f2fs_trim_fs, let's
return without checkpoint.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch relaxes async discard commands to avoid waiting its end_io during
checkpoint.
Instead of waiting them during checkpoint, it will be done when actually reusing
them.

Test on initial partition of nvme drive.

 # time fstrim /mnt/test

Before : 6.158s
After : 4.822s
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds to show the max number of atomic operations which are
conducting concurrently.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch implements IO alignment by filling dummy blocks in DATA and NODE
write bios. If we can guarantee, for example, 32KB or 64KB for such the IOs,
we can eliminate underlying dummy page problem which FTL conducts in order to
close MLC or TLC partial written pages.

Note that,
 - it requires "-o mode=lfs".
 - IO size should be power of 2, not exceed BIO_MAX_PAGES, 256.
 - read IO is still 4KB.
 - do checkpoint at fsync, if dummy NODE page was written.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Otherwise we can remain wrong curseg->next_blkoff, resulting in fsck failure.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

If userspace issue a fstrim with a range not involve prefree segments,
it will reuse these segments without discard. This patch fix it.
Signed-off-by: NYunlei He <heyunlei@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

All block device data fields and functions returning a number of 512B
sectors are by convention named xxx_sectors while names in the form
xxx_size are generally used for a number of bytes. The blk_queue_zone_size
and bdev_zone_size functions were not following this convention so rename
them.

No functional change is introduced by this patch.
Signed-off-by: NDamien Le Moal <damien.lemoal@wdc.com>

Collapsed the two patches, they were nonsensically split and broke
bisection.
Signed-off-by: NJens Axboe <axboe@fb.com>

f2fs_sync_file()             remount_ro
 - f2fs_readonly
                               - destroy_flush_cmd_control
 - f2fs_issue_flush
   - no fcc pointer!

So, this patch doesn't free fcc in this case, but just stop its kernel thread
which sends flush commands.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

The sync_fs in f2fs_balance_fs_bg must avoid interrupting current user requests.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

The addition of multiple-device support broke CONFIG_BLK_DEV_ZONED
on 32-bit machines because of a 64-bit division:

fs/f2fs/f2fs.o: In function `__issue_discard_async':
extent_cache.c:(.text.__issue_discard_async+0xd4): undefined reference to `__aeabi_uldivmod'

Fortunately, bdev_zone_size() is guaranteed to return a power-of-two
number, so we can replace the % operator with a cheaper bit mask.

Fixes: 792b84b74b54 ("f2fs: support multiple devices")
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Drop duplicate header timer.h from segment.c.
Signed-off-by: NGeliang Tang <geliangtang@gmail.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Normally, while committing checkpoint, we will wait on all pages to be
writebacked no matter the page is data or metadata, so in scenario where
there are lots of data IO being submitted with metadata, we may suffer
long latency for waiting writeback during checkpoint.

Indeed, we only care about persistence for pages with metadata, but not
pages with data, as file system consistent are only related to metadate,
so in order to avoid encountering long latency in above scenario, let's
recognize and reference metadata in submitted IOs, wait writeback only
for metadatas.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Previously, written_valid_blocks was got by ckpt->valid_block_count. But if
the last checkpoint has some NEW_ADDR due to power-cut, we can get wrong value.
Fix it to get the number from actual written block count from sit entries.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>