linux-stable.git/fs/f2fs/segment.c, branch linux-3.16.y

f2fs: fix a panic caused by NULL flush_cmd_control

2018-06-16T21:21:30+00:00

commit d4fdf8ba0e5808ba9ad6b44337783bd9935e0982 upstream.

Mount fs with option noflush_merge, boot failed for illegal address
fcc in function f2fs_issue_flush:

        if (!test_opt(sbi, FLUSH_MERGE)) {
                ret = submit_flush_wait(sbi);
                atomic_inc(&fcc->issued_flush);   ->  Here, fcc illegal
                return ret;
        }

Signed-off-by: Yunlei He 
Signed-off-by: Jaegeuk Kim 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

Revert "f2fs: handle dirty segments inside refresh_sit_entry"

2018-02-13T18:42:15+00:00

commit 65f1b80b33378501ea552ef085e9c31739af356c upstream.

This reverts commit 5e443818fa0b2a2845561ee25bec181424fb2889

The commit should be reverted because call sequence of below two parts
of code must be kept:
a. update sit information, it needs to be updated before segment
allocation since latter allocation may trigger SSR, and SSR allocation
needs latest valid block information of all segments.
b. update segment status, it needs to be updated after segment allocation
since we can skip updating current opened segment status.

Fixes: 5e443818fa0b ("f2fs: handle dirty segments inside refresh_sit_entry")
Suggested-by: Chao Yu 
Signed-off-by: Yunlong Song 
Reviewed-by: Chao Yu 
[Jaegeuk Kim: remove refresh_sit_entry function]
Signed-off-by: Jaegeuk Kim 
[bwh: Backported to 3.16:
 - Don't delete refresh_sit_entry(); it has another caller here
 - Adjust context]
Signed-off-by: Ben Hutchings

f2fs: remove redundant lines in allocate_data_block

2018-02-13T18:42:15+00:00

commit 33be828ada7274ebcade2001f16e5b4e33a4636e upstream.

There are redundant lines in allocate_data_block.

In this function, we call refresh_sit_entry with old seg and old curseg.
After that, we call locate_dirty_segment with old curseg.

But, the new address is always allocated from old curseg and
we call locate_dirty_segment with old curseg in refresh_sit_entry.
So, we do not need to call locate_dirty_segment with old curseg again.

We've discussed like below:

Jaegeuk said:
 "When considering SSR, we need to take care of the following scenario.
  - old segno : X
  - new address : Z
  - old curseg : Y
  This means, a new block is supposed to be written to Z from X.
  And Z is newly allocated in the same path from Y.

  In that case, we should trigger locate_dirty_segment for Y, since
  it was a current_segment and can be dirty owing to SSR.
  But that was not included in the dirty list."

Changman said:
 "We already choosed old curseg(Y) and then we allocate new address(Z) from old
  curseg(Y). After that we call refresh_sit_entry(old address, new address).
  In the funcation, we call locate_dirty_segment with old seg and old curseg.
  So calling locate_dirty_segment after refresh_sit_entry again is redundant."

Jaegeuk said:
 "Right. The new address is always allocated from old_curseg."

Reviewed-by: Chao Yu 
Signed-off-by: Dongho Sim 
Signed-off-by: Jaegeuk Kim 
Signed-off-by: Ben Hutchings

f2fs: use for_each_set_bit to simplify the code

2017-06-05T20:17:15+00:00

commit b65ee14818e67127aa242fe1dbd3711b9c095cc0 upstream.

This patch uses for_each_set_bit to simplify some codes in f2fs.

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

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