linux.git/fs/f2fs/debug.c, branch v4.11

f2fs: skip scanning free nid bitmap of full NAT blocks

2017-03-20T14:00:17+00:00

This patch adds to account free nids for each NAT blocks, and while
scanning all free nid bitmap, do check count and skip lookuping in
full NAT block.

Signed-off-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: introduce free nid bitmap

2017-02-27T18:07:47+00:00

In scenario of intensively node allocation, free nids will be ran out
soon, then it needs to stop to load free nids by traversing NAT blocks,
in worse case, if NAT blocks does not be cached in memory, it generates
IOs which slows down our foreground operations.

In order to speed up node allocation, in this patch we introduce a new
free_nid_bitmap array, so there is an bitmap table for each NAT block,
Once the NAT block is loaded, related bitmap cache will be switched on,
and bitmap will be set during traversing nat entries in NAT block, later
we can query and update nid usage status in memory completely.

With such implementation, I expect performance of node allocation can be
improved in the long-term after filesystem image is mounted.

Signed-off-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: add bitmaps for empty or full NAT blocks

2017-02-27T17:59:54+00:00

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: Jaegeuk Kim

f2fs: show # of APPEND and UPDATE inodes

2017-02-23T04:54:53+00:00

This patch shows cached # of APPEND and UPDATE inode entries.

Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: show # of on-going flush and discard bios

2017-02-23T04:24:47+00:00

This patch adds stat information for flush and discard commands.

Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: factor out discard command info into discard_cmd_control

2017-02-23T02:48:53+00:00

This patch adds discard_cmd_control with the existing discarding controls.

Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: reorganize stat information

2017-02-23T02:48:52+00:00

This patch modifies stat information more clearly.

Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: clean up flush/discard command namings

2017-02-23T02:48:51+00:00

This patch simply cleans up the names for flush/discard commands.

Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: show the max number of atomic operations

2017-01-29T03:46:01+00:00

This patch adds to show the max number of atomic operations which are
conducting concurrently.

Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: set ->owner for debugfs status file's file_operations

2016-11-25T18:16:08+00:00

The struct file_operations instance serving the f2fs/status debugfs file
lacks an initialization of its ->owner.

This means that although that file might have been opened, the f2fs module
can still get removed. Any further operation on that opened file, releasing
included,  will cause accesses to unmapped memory.

Indeed, Mike Marshall reported the following:

  BUG: unable to handle kernel paging request at ffffffffa0307430
  IP: [] full_proxy_release+0x24/0x90
  <...>
  Call Trace:
   [] __fput+0xdf/0x1d0
   [] ____fput+0xe/0x10
   [] task_work_run+0x8e/0xc0
   [] do_exit+0x2ae/0xae0
   [] ? __audit_syscall_entry+0xae/0x100
   [] ? syscall_trace_enter+0x1ca/0x310
   [] do_group_exit+0x44/0xc0
   [] SyS_exit_group+0x14/0x20
   [] do_syscall_64+0x61/0x150
   [] entry_SYSCALL64_slow_path+0x25/0x25
  <...>
  ---[ end trace f22ae883fa3ea6b8 ]---
  Fixing recursive fault but reboot is needed!

Fix this by initializing the f2fs/status file_operations' ->owner with
THIS_MODULE.

This will allow debugfs to grab a reference to the f2fs module upon any
open on that file, thus preventing it from getting removed.

Fixes: 902829aa0b72 ("f2fs: move proc files to debugfs")
Reported-by: Mike Marshall 
Reported-by: Martin Brandenburg 
Cc: stable@vger.kernel.org
Signed-off-by: Nicolai Stange 
Signed-off-by: Jaegeuk Kim