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>

1 files changed, 24 insertions, 11 deletions

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index e73ce11de02d..382c1ef9a9e4 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -875,6 +875,7 @@ static int __allocate_data_block(struct dnode_of_data *dn, int seg_type)
 	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
 	struct f2fs_summary sum;
 	struct node_info ni;
+	block_t old_blkaddr;
 	pgoff_t fofs;
 	blkcnt_t count = 1;
 	int err;
@@ -896,9 +897,12 @@ static int __allocate_data_block(struct dnode_of_data *dn, int seg_type)
 
 alloc:
 	set_summary(&sum, dn->nid, dn->ofs_in_node, ni.version);
-
-	f2fs_allocate_data_block(sbi, NULL, dn->data_blkaddr, &dn->data_blkaddr,
+	old_blkaddr = dn->data_blkaddr;
+	f2fs_allocate_data_block(sbi, NULL, old_blkaddr, &dn->data_blkaddr,
 					&sum, seg_type, NULL, false);
+	if (GET_SEGNO(sbi, old_blkaddr) != NULL_SEGNO)
+		invalidate_mapping_pages(META_MAPPING(sbi),
+					old_blkaddr, old_blkaddr);
 	f2fs_set_data_blkaddr(dn);
 
 	/* update i_size */
@@ -1614,6 +1618,7 @@ static int f2fs_read_data_pages(struct file *file,
 static int encrypt_one_page(struct f2fs_io_info *fio)
 {
 	struct inode *inode = fio->page->mapping->host;
+	struct page *mpage;
 	gfp_t gfp_flags = GFP_NOFS;
 
 	if (!f2fs_encrypted_file(inode))
@@ -1625,17 +1630,25 @@ static int encrypt_one_page(struct f2fs_io_info *fio)
 retry_encrypt:
 	fio->encrypted_page = fscrypt_encrypt_page(inode, fio->page,
 			PAGE_SIZE, 0, fio->page->index, gfp_flags);
-	if (!IS_ERR(fio->encrypted_page))
-		return 0;
+	if (IS_ERR(fio->encrypted_page)) {
+		/* flush pending IOs and wait for a while in the ENOMEM case */
+		if (PTR_ERR(fio->encrypted_page) == -ENOMEM) {
+			f2fs_flush_merged_writes(fio->sbi);
+			congestion_wait(BLK_RW_ASYNC, HZ/50);
+			gfp_flags |= __GFP_NOFAIL;
+			goto retry_encrypt;
+		}
+		return PTR_ERR(fio->encrypted_page);
+	}
 
-	/* flush pending IOs and wait for a while in the ENOMEM case */
-	if (PTR_ERR(fio->encrypted_page) == -ENOMEM) {
-		f2fs_flush_merged_writes(fio->sbi);
-		congestion_wait(BLK_RW_ASYNC, HZ/50);
-		gfp_flags |= __GFP_NOFAIL;
-		goto retry_encrypt;
+	mpage = find_lock_page(META_MAPPING(fio->sbi), fio->old_blkaddr);
+	if (mpage) {
+		if (PageUptodate(mpage))
+			memcpy(page_address(mpage),
+				page_address(fio->encrypted_page), PAGE_SIZE);
+		f2fs_put_page(mpage, 1);
 	}
-	return PTR_ERR(fio->encrypted_page);
+	return 0;
 }
 
 static inline bool check_inplace_update_policy(struct inode *inode,