nilfs2: add reader's lock for cno in nilfs_ioctl_sync

This adds reader's lock for the_nilfs->cno in nilfs_ioctl_sync,
for the_nilfs->cno should be proctected by segctor_sem when reading.

Signed-off-by: Jiro SEKIBA <jir@unicus.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
This commit is contained in:
Jiro SEKIBA 2010-02-20 19:47:49 +09:00 committed by Ryusuke Konishi
parent 03f29365e8
commit 0d561f12b4

View File

@ -601,13 +601,17 @@ static int nilfs_ioctl_sync(struct inode *inode, struct file *filp,
{
__u64 cno;
int ret;
struct the_nilfs *nilfs;
ret = nilfs_construct_segment(inode->i_sb);
if (ret < 0)
return ret;
if (argp != NULL) {
cno = NILFS_SB(inode->i_sb)->s_nilfs->ns_cno - 1;
nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
down_read(&nilfs->ns_segctor_sem);
cno = nilfs->ns_cno - 1;
up_read(&nilfs->ns_segctor_sem);
if (copy_to_user(argp, &cno, sizeof(cno)))
return -EFAULT;
}