tree 395d592f87d039459d4e96b022bfd51d39e757cc
parent f64b4d7990244c556fa251007c74dbec091aa16f
author Chao Yu <yuchao0@huawei.com> 1534257445 +0800
committer Jaegeuk Kim <jaegeuk@kernel.org> 1537302317 -0700

f2fs: readahead encrypted block during GC

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 <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>