From df6136ef5533421e68ea7ff9c33d5b2ac9005ff9 Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Mon, 23 Mar 2015 10:33:37 +0800 Subject: [PATCH] f2fs: preallocate fallocated blocks for direct IO Normally, due to DIO_SKIP_HOLES flag is set by default, blockdev_direct_IO in f2fs_direct_IO tries to skip DIO in holes when writing inside i_size, this makes us falling back to buffered IO which shows lower performance. So in commit 59b802e5a453 ("f2fs: allocate data blocks in advance for f2fs_direct_IO"), we improve perfromance by allocating data blocks in advance if we meet holes no matter in i_size or not, since with it we can avoid falling back to buffered IO. But we forget to consider for unwritten fallocated block in this commit. This patch tries to fix it for fallocate case, this helps to improve performance. Test result: Storage info: sandisk ultra 64G micro sd card. touch /mnt/f2fs/file truncate -s 67108864 /mnt/f2fs/file fallocate -o 0 -l 67108864 /mnt/f2fs/file time dd if=/dev/zero of=/mnt/f2fs/file bs=1M count=64 conv=notrunc oflag=direct Time before applying the patch: 67108864 bytes (67 MB) copied, 36.16 s, 1.9 MB/s real 0m36.162s user 0m0.000s sys 0m0.180s Time after applying the patch: 67108864 bytes (67 MB) copied, 27.7776 s, 2.4 MB/s real 0m27.780s user 0m0.000s sys 0m0.036s Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim --- fs/f2fs/data.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 8a940e5..614e444 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -1126,16 +1126,23 @@ static int __allocate_data_block(struct dnode_of_data *dn) if (unlikely(is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC))) return -EPERM; + + dn->data_blkaddr = datablock_addr(dn->node_page, dn->ofs_in_node); + if (dn->data_blkaddr == NEW_ADDR) + goto alloc; + if (unlikely(!inc_valid_block_count(sbi, dn->inode, 1))) return -ENOSPC; +alloc: get_node_info(sbi, dn->nid, &ni); set_summary(&sum, dn->nid, dn->ofs_in_node, ni.version); if (dn->ofs_in_node == 0 && dn->inode_page == dn->node_page) seg = CURSEG_DIRECT_IO; - allocate_data_block(sbi, NULL, NULL_ADDR, &dn->data_blkaddr, &sum, seg); + allocate_data_block(sbi, NULL, dn->data_blkaddr, &dn->data_blkaddr, + &sum, seg); /* direct IO doesn't use extent cache to maximize the performance */ set_data_blkaddr(dn); @@ -1175,7 +1182,7 @@ static void __allocate_data_blocks(struct inode *inode, loff_t offset, block_t blkaddr; blkaddr = datablock_addr(dn.node_page, dn.ofs_in_node); - if (blkaddr == NULL_ADDR) { + if (blkaddr == NULL_ADDR || blkaddr == NEW_ADDR) { if (__allocate_data_block(&dn)) goto sync_out; allocated = true; -- 2.7.4