linux.git/fs/f2fs/debug.c, branch v4.10

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

f2fs: don't wait writeback for datas during checkpoint

2016-11-25T18:15:59+00:00

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: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: remove percpu_count due to performance regression

2016-11-23T20:11:10+00:00

This patch removes percpu_count usage due to performance regression in iozone.

Fixes: 523be8a6b3 ("f2fs: use percpu_counter for page counters")
Signed-off-by: Jaegeuk Kim

f2fs: split free nid list

2016-11-23T20:11:00+00:00

During free nid allocation, in order to do preallocation, we will tag free
nid entry as allocated one and still leave it in free nid list, for other
allocators who want to grab free nids, it needs to traverse the free nid
list for lookup. It becomes overhead in scenario of allocating free nid
intensively by multithreads.

This patch splits free nid list to two list: {free,alloc}_nid_list, to
keep free nids and preallocated free nids separately, after that, traverse
latency will be gone, besides split nid_cnt for separate statistic.

Additionally, introduce __insert_nid_to_list and __remove_nid_from_list for
cleanup.

Signed-off-by: Chao Yu 
[Jaegeuk Kim: modify f2fs_bug_on to avoid needless branches]
Signed-off-by: Jaegeuk Kim

f2fs: show dirty inode number

2016-09-22T18:43:07+00:00

This patch enables showing dirty inode number in procfs.

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

f2fs: add discard info to sys entry of f2fs status

2016-08-30T01:31:06+00:00

This patch add discard block count to sys entry of f2fs status

Signed-off-by: Yunlei He 
Signed-off-by: Jaegeuk Kim

f2fs: do not use discard_map for hard disks

2016-08-24T17:16:14+00:00

We don't need to keep discard_map, if disk does not support discard command.

Signed-off-by: Jaegeuk Kim

f2fs: flush inode metadata when checkpoint is doing

2016-06-03T01:05:11+00:00

This patch registers all the inodes which have dirty metadata to sync when
checkpoint is doing.

Signed-off-by: Jaegeuk Kim

f2fs: use percpu_counter for page counters

2016-05-18T20:57:27+00:00

This patch substitutes percpu_counter for atomic_counter when counting
various types of pages.

Signed-off-by: Jaegeuk Kim

f2fs: use bio count instead of F2FS_WRITEBACK page count

2016-05-18T20:57:25+00:00

This can reduce page counting overhead.

Signed-off-by: Jaegeuk Kim