linux-stable.git/fs/f2fs/debug.c, branch v4.9.2

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

2017-01-06T09:40:14+00:00

commit 05e6ea2685c964db1e675a24a4f4e2adc22d2388 upstream.

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 
Signed-off-by: Nicolai Stange 
Signed-off-by: Jaegeuk Kim 
Signed-off-by: Greg Kroah-Hartman

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

f2fs: show # of orphan inodes

2016-05-11T16:56:36+00:00

This adds debug information for # of orphan inodes.

Signed-off-by: Jaegeuk Kim

f2fs: show current mount status

2016-04-15T15:49:47+00:00

This patch remains the current mount status to f2fs status info.

Signed-off-by: Jaegeuk Kim

mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros

2016-04-04T17:41:08+00:00

PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.

This promise never materialized.  And unlikely will.

We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE.  And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.

Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.

Let's stop pretending that pages in page cache are special.  They are
not.

The changes are pretty straight-forward:

 -  << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> ;

 -  >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> ;

 - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};

 - page_cache_get() -> get_page();

 - page_cache_release() -> put_page();

This patch contains automated changes generated with coccinelle using
script below.  For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.

The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.

There are few places in the code where coccinelle didn't reach.  I'll
fix them manually in a separate patch.  Comments and documentation also
will be addressed with the separate patch.

virtual patch

@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT

@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE

@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK

@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)

@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)

@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)

Signed-off-by: Kirill A. Shutemov 
Acked-by: Michal Hocko 
Signed-off-by: Linus Torvalds