linux.git/fs/f2fs/segment.c, branch v4.15

f2fs: apply write hints to select the type of segments for buffered write

2017-11-09T18:18:16+00:00

Write hints helps F2FS to determine which type of segments would be
selected for buffered write.

This patch implements the mapping from write hints to segment types
as shown below.

  hints               segment type
  -----               ------------
  WRITE_LIFE_SHORT    CURSEG_HOT_DATA
  WRITE_LIFE_EXTREME  CURSEG_COLD_DATA
  others              CURSEG_WARM_DATA

the F2FS poliy for hot/cold seperation has precedence over this hints.
And hints are not applied in in-place update.

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

f2fs: fix summary info corruption

2017-11-06T00:42:08+00:00

Sometimes, after running generic/270 of fstest, fsck reports summary
info and actual position of block address in direct node becoming
inconsistent.

The root cause is race in between __f2fs_replace_block and change_curseg
as below:

Thread A				Thread B
- __clone_blkaddrs
 - f2fs_replace_block
  - __f2fs_replace_block
   - segnoA = GET_SEGNO(sbi, blkaddrA);
   - type = se->type:=CURSEG_HOT_DATA
   - if (!IS_CURSEG(sbi, segnoA))
         type = CURSEG_WARM_DATA
					- allocate_data_block
					 - allocate_segment
					  - get_ssr_segment
					  - change_curseg(segnoA, CURSEG_HOT_DATA)
   - change_curseg(segnoA, CURSEG_WARM_DATA)
    - reset_curseg
     - __set_sit_entry_type
      - change se->type from CURSEG_HOT_DATA to CURSEG_WARM_DATA

So finally, hot curseg locates in segnoA, but type of segnoA becomes
CURSEG_WARM_DATA.

Then if we invoke __f2fs_replace_block(blkaddrB, blkaddrA, true, false),
as blkaddrA locates in segnoA, so we will move warm type curseg to segnoA,
then change its summary cache and writeback it to summary block.

But segnoA is used by hot type curseg too, once it moves or persist, it
will cover summary block content with inner old summary cache, result in
inconsistent status.

This patch tries to fix this issue by introduce global curseg lock to avoid
race in between __f2fs_replace_block and change_curseg.

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

f2fs: remove dead code in update_meta_page

2017-11-06T00:42:07+00:00

After commit a468f0ef516f ("f2fs: use crc and cp version to determine
roll-forward recovery"), last caller of update_meta_page passing @src
with NULL is gone, so remove related dead code there.

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

f2fs: use rw_semaphore to protect SIT cache

2017-11-06T00:42:03+00:00

There are some cases user didn't update SIT cache under this lock,
so let's use rw_semaphore instead of mutex to enhance concurrently
accessing.

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

Revert "f2fs: handle dirty segments inside refresh_sit_entry"

2017-11-06T00:41:58+00:00

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

f2fs: export SSR allocation threshold

2017-11-06T00:41:57+00:00

This patch exports min_ssr_segments threshold in sysfs to let user
control triggering SSR allocation flexibly.

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

f2fs: give correct trimmed blocks in fstrim

2017-11-06T00:41:56+00:00

We have supported to issue discard in specified range during fstrim,
it needs to return caller with successfully trimmed bytes in that
range instead of bytes of invalid blocks which are scanned in
checkpoint.

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

f2fs: support bio allocation error injection

2017-11-06T00:41:55+00:00

This patch adds to support bio allocation error injection to simulate
out-of-memory test scenario.

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

f2fs: remove several redundant assignments

2017-10-26T08:44:26+00:00

There are several assignments to variables that are redundant
as the values are never read when the variables are updated later
and so the redundant statements can be safely removed.

Cleans up clang warnings:
fs/f2fs/segment.c:923:19: warning: Value stored to 'p' during its initialization is never read
fs/f2fs/segment.c:2060:2: warning: Value stored to 'hint' is never read
fs/f2fs/segment.c:2353:2: warning: Value stored to 'start_block' is never read
fs/f2fs/segment.c:2354:2: warning: Value stored to 'end_block' is never read

Signed-off-by: Colin Ian King 
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: limit # of inmemory pages

2017-10-26T08:44:21+00:00

If some abnormal users try lots of atomic write operations, f2fs is able to
produce pinned pages in the main memory which affects system performance.
This patch limits that as 20% over total memory size, and if f2fs reaches
to the limit, it will drop all the inmemory pages.

Signed-off-by: Jaegeuk Kim