f2fs: shrink node_write lock coverage

- to avoid race between checkpoint and quota file writeback, it
just needs to hold read lock of node_write in writeback path.
- node_write lock has covered all LFS data write paths, it's not
necessary, we only need to hold node_write lock at write path of
quota file.

This refactors commit ca7f76e680 ("f2fs: fix wrong discard space").

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This commit is contained in:
Chao Yu 2020-06-18 14:36:23 +08:00 committed by Jaegeuk Kim
parent fa6795552a
commit 79963d967b
3 changed files with 27 additions and 14 deletions

View file

@ -1096,8 +1096,16 @@ static int f2fs_write_compressed_pages(struct compress_ctx *cc,
loff_t psize;
int i, err;
if (!IS_NOQUOTA(inode) && !f2fs_trylock_op(sbi))
if (IS_NOQUOTA(inode)) {
/*
* We need to wait for node_write to avoid block allocation during
* checkpoint. This can only happen to quota writes which can cause
* the below discard race condition.
*/
down_read(&sbi->node_write);
} else if (!f2fs_trylock_op(sbi)) {
return -EAGAIN;
}
set_new_dnode(&dn, cc->inode, NULL, NULL, 0);
@ -1203,7 +1211,9 @@ static int f2fs_write_compressed_pages(struct compress_ctx *cc,
set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN);
f2fs_put_dnode(&dn);
if (!IS_NOQUOTA(inode))
if (IS_NOQUOTA(inode))
up_read(&sbi->node_write);
else
f2fs_unlock_op(sbi);
spin_lock(&fi->i_size_lock);
@ -1230,7 +1240,9 @@ static int f2fs_write_compressed_pages(struct compress_ctx *cc,
out_put_dnode:
f2fs_put_dnode(&dn);
out_unlock_op:
if (!IS_NOQUOTA(inode))
if (IS_NOQUOTA(inode))
up_read(&sbi->node_write);
else
f2fs_unlock_op(sbi);
return -EAGAIN;
}

View file

@ -2719,8 +2719,20 @@ int f2fs_write_single_data_page(struct page *page, int *submitted,
/* Dentry/quota blocks are controlled by checkpoint */
if (S_ISDIR(inode->i_mode) || IS_NOQUOTA(inode)) {
/*
* We need to wait for node_write to avoid block allocation during
* checkpoint. This can only happen to quota writes which can cause
* the below discard race condition.
*/
if (IS_NOQUOTA(inode))
down_read(&sbi->node_write);
fio.need_lock = LOCK_DONE;
err = f2fs_do_write_data_page(&fio);
if (IS_NOQUOTA(inode))
up_read(&sbi->node_write);
goto done;
}

View file

@ -3133,14 +3133,6 @@ void f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
type = CURSEG_COLD_DATA;
}
/*
* We need to wait for node_write to avoid block allocation during
* checkpoint. This can only happen to quota writes which can cause
* the below discard race condition.
*/
if (IS_DATASEG(type))
down_write(&sbi->node_write);
down_read(&SM_I(sbi)->curseg_lock);
mutex_lock(&curseg->curseg_mutex);
@ -3206,9 +3198,6 @@ void f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
up_read(&SM_I(sbi)->curseg_lock);
if (IS_DATASEG(type))
up_write(&sbi->node_write);
if (put_pin_sem)
up_read(&sbi->pin_sem);
}