linux.git/fs/f2fs/segment.c, branch v4.19

f2fs: readahead encrypted block during GC

2018-08-21T06:13:42+00:00

During GC, for each encrypted block, we will read block synchronously
into meta page, and then submit it into current cold data log area.

So this block read model with 4k granularity can make poor performance,
like migrating non-encrypted block, let's readahead encrypted block
as well to improve migration performance.

To implement this, we choose meta page that its index is old block
address of the encrypted block, and readahead ciphertext into this
page, later, if readaheaded page is still updated, we will load its
data into target meta page, and submit the write IO.

Note that for OPU, truncation, deletion, we need to invalid meta
page after we invalid old block address, to make sure we won't load
invalid data from target meta page during encrypted block migration.

for ((i = 0; i < 1000; i++))
do {
        xfs_io -f /mnt/f2fs/dir/$i -c "pwrite 0 128k" -c "fsync";
} done

for ((i = 0; i < 1000; i+=2))
do {
        rm /mnt/f2fs/dir/$i;
} done

ret = ioctl(fd, F2FS_IOC_GARBAGE_COLLECT, 0);

Before:
              gc-6549  [001] d..1 214682.212797: block_rq_insert: 8,32 RA 32768 () 786400 + 64 [gc]
              gc-6549  [001] d..1 214682.212802: block_unplug: [gc] 1
              gc-6549  [001] .... 214682.213892: block_bio_queue: 8,32 R 67494144 + 8 [gc]
              gc-6549  [001] .... 214682.213899: block_getrq: 8,32 R 67494144 + 8 [gc]
              gc-6549  [001] .... 214682.213902: block_plug: [gc]
              gc-6549  [001] d..1 214682.213905: block_rq_insert: 8,32 R 4096 () 67494144 + 8 [gc]
              gc-6549  [001] d..1 214682.213908: block_unplug: [gc] 1
              gc-6549  [001] .... 214682.226405: block_bio_queue: 8,32 R 67494152 + 8 [gc]
              gc-6549  [001] .... 214682.226412: block_getrq: 8,32 R 67494152 + 8 [gc]
              gc-6549  [001] .... 214682.226414: block_plug: [gc]
              gc-6549  [001] d..1 214682.226417: block_rq_insert: 8,32 R 4096 () 67494152 + 8 [gc]
              gc-6549  [001] d..1 214682.226420: block_unplug: [gc] 1
              gc-6549  [001] .... 214682.226904: block_bio_queue: 8,32 R 67494160 + 8 [gc]
              gc-6549  [001] .... 214682.226910: block_getrq: 8,32 R 67494160 + 8 [gc]
              gc-6549  [001] .... 214682.226911: block_plug: [gc]
              gc-6549  [001] d..1 214682.226914: block_rq_insert: 8,32 R 4096 () 67494160 + 8 [gc]
              gc-6549  [001] d..1 214682.226916: block_unplug: [gc] 1

After:
              gc-5678  [003] .... 214327.025906: block_bio_queue: 8,32 R 67493824 + 8 [gc]
              gc-5678  [003] .... 214327.025908: block_bio_backmerge: 8,32 R 67493824 + 8 [gc]
              gc-5678  [003] .... 214327.025915: block_bio_queue: 8,32 R 67493832 + 8 [gc]
              gc-5678  [003] .... 214327.025917: block_bio_backmerge: 8,32 R 67493832 + 8 [gc]
              gc-5678  [003] .... 214327.025923: block_bio_queue: 8,32 R 67493840 + 8 [gc]
              gc-5678  [003] .... 214327.025925: block_bio_backmerge: 8,32 R 67493840 + 8 [gc]
              gc-5678  [003] .... 214327.025932: block_bio_queue: 8,32 R 67493848 + 8 [gc]
              gc-5678  [003] .... 214327.025934: block_bio_backmerge: 8,32 R 67493848 + 8 [gc]
              gc-5678  [003] .... 214327.025941: block_bio_queue: 8,32 R 67493856 + 8 [gc]
              gc-5678  [003] .... 214327.025943: block_bio_backmerge: 8,32 R 67493856 + 8 [gc]
              gc-5678  [003] .... 214327.025953: block_bio_queue: 8,32 R 67493864 + 8 [gc]
              gc-5678  [003] .... 214327.025955: block_bio_backmerge: 8,32 R 67493864 + 8 [gc]
              gc-5678  [003] .... 214327.025962: block_bio_queue: 8,32 R 67493872 + 8 [gc]
              gc-5678  [003] .... 214327.025964: block_bio_backmerge: 8,32 R 67493872 + 8 [gc]
              gc-5678  [003] .... 214327.025970: block_bio_queue: 8,32 R 67493880 + 8 [gc]
              gc-5678  [003] .... 214327.025972: block_bio_backmerge: 8,32 R 67493880 + 8 [gc]
              gc-5678  [003] .... 214327.026000: block_bio_queue: 8,32 WS 34123776 + 2048 [gc]
              gc-5678  [003] .... 214327.026019: block_getrq: 8,32 WS 34123776 + 2048 [gc]
              gc-5678  [003] d..1 214327.026021: block_rq_insert: 8,32 R 131072 () 67493632 + 256 [gc]
              gc-5678  [003] d..1 214327.026023: block_unplug: [gc] 1
              gc-5678  [003] d..1 214327.026026: block_rq_issue: 8,32 R 131072 () 67493632 + 256 [gc]
              gc-5678  [003] .... 214327.026046: block_plug: [gc]

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

f2fs: avoid fi->i_gc_rwsem[WRITE] lock in f2fs_gc

2018-08-21T06:13:42+00:00

The f2fs_gc() called by f2fs_balance_fs() requires to be called outside of
fi->i_gc_rwsem[WRITE], since f2fs_gc() can try to grab it in a loop.

If it hits the miximum retrials in GC, let's give a chance to release
gc_mutex for a short time in order not to go into live lock in the worst
case.

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

f2fs: fix performance issue observed with multi-thread sequential read

2018-08-21T06:13:42+00:00

This reverts the commit - "b93f771 - f2fs: remove writepages lock"
to fix the drop in sequential read throughput.

Test: ./tiotest -t 32 -d /data/tio_tmp -f 32 -b 524288 -k 1 -k 3 -L
device: UFS

Before -
read throughput: 185 MB/s
total read requests: 85177 (of these ~80000 are 4KB size requests).
total write requests: 2546 (of these ~2208 requests are written in 512KB).

After -
read throughput: 758 MB/s
total read requests: 2417 (of these ~2042 are 512KB reads).
total write requests: 2701 (of these ~2034 requests are written in 512KB).

Signed-off-by: Sahitya Tummala 
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: rework fault injection handling to avoid a warning

2018-08-14T16:49:15+00:00

When CONFIG_F2FS_FAULT_INJECTION is disabled, we get a warning about an
unused label:

fs/f2fs/segment.c: In function '__submit_discard_cmd':
fs/f2fs/segment.c:1059:1: error: label 'submit' defined but not used [-Werror=unused-label]

This could be fixed by adding another #ifdef around it, but the more
reliable way of doing this seems to be to remove the other #ifdefs
where that is easily possible.

By defining time_to_inject() as a trivial stub, most of the checks for
CONFIG_F2FS_FAULT_INJECTION can go away. This also leads to nicer
formatting of the code.

Signed-off-by: Arnd Bergmann 
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: fix to return success when trimming meta area

2018-08-13T17:48:17+00:00

generic/251
    --- tests/generic/251.out	2016-05-03 20:20:11.381899000 +0800
     QA output created by 251
     Running the test: done.
    +fstrim: /mnt/scratch_f2fs: FITRIM ioctl failed: Invalid argument
    +fstrim: /mnt/scratch_f2fs: FITRIM ioctl failed: Invalid argument
    +fstrim: /mnt/scratch_f2fs: FITRIM ioctl failed: Invalid argument
    +fstrim: /mnt/scratch_f2fs: FITRIM ioctl failed: Invalid argument
    +fstrim: /mnt/scratch_f2fs: FITRIM ioctl failed: Invalid argument
    ...
Ran: generic/251
Failures: generic/251

The reason is coverage of fstrim locates in meta area, previously we
just return -EINVAL for such case, making generic/251 failed, to fix
this problem, let's relieve restriction to return success with no
block discarded.

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

f2fs: fix use-after-free of dicard command entry

2018-08-13T17:48:17+00:00

As Dan Carpenter reported:

The patch 20ee4382322c: "f2fs: issue small discard by LBA order" from
Jul 8, 2018, leads to the following Smatch warning:

	fs/f2fs/segment.c:1277 __issue_discard_cmd_orderly()
	warn: 'dc' was already freed.

See also:
fs/f2fs/segment.c:2550 __issue_discard_cmd_range() warn: 'dc' was already freed.

In order to fix this issue, let's get error from __submit_discard_cmd(),
and release current discard command after we referenced next one.

Reported-by: Dan Carpenter 
Signed-off-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: support discard submission error injection

2018-08-13T17:48:17+00:00

This patch adds to support discard submission error injection for testing
error handling of __submit_discard_cmd().

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

f2fs: split discard command in prior to block layer

2018-08-13T17:48:17+00:00

Some devices has small max_{hw,}discard_sectors, so that in
__blkdev_issue_discard(), one big size discard bio can be split
into multiple small size discard bios, result in heavy load in IO
scheduler and device, which can hang other sync IO for long time.

Now, f2fs is trying to control discard commands more elaboratively,
in order to make less conflict in between discard IO and user IO
to enhance application's performance, so in this patch, we will
split discard bio in f2fs in prior to in block layer to reduce
issuing multiple discard bios in a short time.

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

f2fs: fix incorrect range->len in f2fs_trim_fs()

2018-08-13T17:48:17+00:00

generic/260 reported below error:

     [+] Default length with start set (should succeed)
     [+] Length beyond the end of fs (should succeed)
     [+] Length beyond the end of fs with start set (should succeed)
    +./tests/generic/260: line 94: [: 18446744073709551615: integer expression expected
    +./tests/generic/260: line 104: [: 18446744073709551615: integer expression expected
     Test done
    ...

In f2fs_trim_fs(), if there is no discard being trimmed, we need to correct
range->len before return.

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

f2fs: let checkpoint flush dnode page of regular

2018-08-01T18:52:36+00:00

Fsyncer will wait on all dnode pages of regular writeback before flushing,
if there are async dnode pages blocked by IO scheduler, it may decrease
fsync's performance.

In this patch, we choose to let f2fs_balance_fs_bg() to trigger checkpoint
to flush these dnode pages of regular, so async IO of dnode page can be
elimitnated, making fsyncer only need to wait for sync IO.

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