linux.git/fs/f2fs/segment.c, branch v3.16

f2fs: avoid to access NULL pointer in issue_flush_thread

2014-07-09T12:59:55+00:00

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=75861

Denis 2014-05-10 11:28:59 UTC reported:
"F2FS-fs (mmcblk0p28): mounting..
 Unable to handle kernel NULL pointer dereference at virtual address 00000018
 ...
 [] (_raw_spin_lock+0x3c/0x70) from [] (issue_flush_thread+0x50/0x17c)
 [] (issue_flush_thread+0x50/0x17c) from [] (kthread+0x98/0xa4)
 [] (kthread+0x98/0xa4) from [] (kernel_thread_exit+0x0/0x8)"

This patch assign cmd_control_info in sm_info before issue_flush_thread is being
created, so this make sure that issue flush thread will have no chance to access
invalid info in fcc.

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

f2fs: remove unused variables in f2fs_sm_info

2014-07-09T12:57:57+00:00

Remove unused variables in struct f2fs_sm_info.

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

f2fs: avoid to use slab memory in f2fs_issue_flush for efficiency

2014-05-08T09:23:21+00:00

If we use slab memory in f2fs_issue_flush(), we will face memory pressure and
latency time caused by racing of kmem_cache_{alloc,free}.

Let's alloc memory in stack instead of slab.

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

f2fs: introduce help function {create,destroy}_flush_cmd_control

2014-05-07T01:21:57+00:00

Introduce help function {create,destroy}_flush_cmd_control to clean up
the create/destory flush merge operation.

Signed-off-by: Gu Zheng 
Signed-off-by: Jaegeuk Kim

f2fs: introduce struct flush_cmd_control to wrap the flush_merge fields

2014-05-07T01:21:56+00:00

Split the flush_merge fields from sm_i, and use the new struct flush_cmd_control
to wrap it, so that we can igonre these fileds if flush_merge is disable, and
it alse can the structs more neat.

Signed-off-by: Gu Zheng 
Signed-off-by: Jaegeuk Kim

f2fs: add the flush_merge handle in the remount flow

2014-05-07T01:21:55+00:00

Add the *remount* handle of flush_merge option, so that the users
can enable flush_merge in the runtime, such as the underlying device
handles the cache_flush command relatively slowly.

Signed-off-by: Gu Zheng 
Signed-off-by: Jaegeuk Kim

f2fs: avoid to conduct roll-forward due to the remained garbage blocks

2014-05-07T01:21:54+00:00

The f2fs always scans the next chain of direct node blocks.
But some garbage blocks are able to be remained due to no discard support or
SSR triggers.
This occasionally wreaks recovering wrong inodes that were used or BUG_ONs
due to reallocating node ids as follows.

When mount this f2fs image:
http://linuxtesting.org/downloads/f2fs_fault_image.zip
BUG_ON is triggered in f2fs driver (messages below are generated on
kernel 3.13.2; for other kernels output is similar):

kernel BUG at fs/f2fs/node.c:215!
 Call Trace:
 [] recover_inode_page+0x1fd/0x3e0 [f2fs]
 [] ? __lock_page+0x67/0x70
 [] ? autoremove_wake_function+0x50/0x50
 [] recover_fsync_data+0x1398/0x15d0 [f2fs]
 [] ? selinux_d_instantiate+0x1c/0x20
 [] ? d_instantiate+0x5b/0x80
 [] f2fs_fill_super+0xb04/0xbf0 [f2fs]
 [] ? mount_bdev+0x7e/0x210
 [] mount_bdev+0x1c9/0x210
 [] ? validate_superblock+0x210/0x210 [f2fs]
 [] f2fs_mount+0x1d/0x30 [f2fs]
 [] mount_fs+0x47/0x1c0
 [] ? __alloc_percpu+0x10/0x20
 [] vfs_kern_mount+0x72/0x110
 [] do_mount+0x493/0x910
 [] ? strndup_user+0x5b/0x80
 [] SyS_mount+0x90/0xe0
 [] system_call_fastpath+0x16/0x1b

Found by Linux File System Verification project (linuxtesting.org).

Reported-by: Andrey Tsyvarev 
Signed-off-by: Jaegeuk Kim

f2fs: enable flush_merge only in f2fs is not read-only

2014-05-07T01:21:54+00:00

Enable flush_merge only in f2fs is not read-only, so does the mount
option show.

Signed-off-by: Gu Zheng 
Signed-off-by: Jaegeuk Kim

f2fs: use __GFP_ZERO to avoid appending set-NULL

2014-05-07T01:21:53+00:00

Signed-off-by: Gu Zheng 
Signed-off-by: Jaegeuk Kim

f2fs: put the bio when issue_flush completed

2014-05-07T01:21:53+00:00

Put the bio when the flush cmd issued, it also can fix the following
kmemleak:
unreferenced object 0xffff8800270c73c0 (size 200):
  comm "f2fs_flush-7:0", pid 27161, jiffies 4312127988 (age 988.503s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 40 07 81 19 01 88 ff ff  ........@.......
    01 00 00 00 00 00 00 f0 11 14 00 00 00 00 00 00  ................
  backtrace:
    [] kmemleak_alloc+0x72/0x96
    [] slab_post_alloc_hook+0x28/0x2a
    [] kmem_cache_alloc+0xec/0x157
    [] mempool_alloc_slab+0x15/0x17
    [] mempool_alloc+0x71/0x138
    [] bio_alloc_bioset+0x93/0x18c
    [] issue_flush_thread+0x8d/0x145 [f2fs]
    [] kthread+0xba/0xc2
    [] ret_from_fork+0x7c/0xb0
    [] 0xffffffffffffffff

Signed-off-by: Gu Zheng 
Signed-off-by: Jaegeuk Kim