On Wed, 2022-08-31 at 10:16 +0800, xiubli@xxxxxxxxxx wrote: > From: Xiubo Li <xiubli@xxxxxxxxxx> > > When unlinking a file the kclient will send a unlink request to MDS > by holding the dentry reference, and then the MDS will return 2 replies, > which are unsafe reply and a deferred safe reply. > > After the unsafe reply received the kernel will return and succeed > the unlink request to user space apps. > > Only when the safe reply received the dentry's reference will be > released. Or the dentry will only be unhashed from dcache. But when > the open_by_handle_at() begins to open the unlinked files it will > succeed. > > The inode->i_count couldn't be used to check whether the inode is > opened or not. > > URL: https://tracker.ceph.com/issues/56524 > Signed-off-by: Xiubo Li <xiubli@xxxxxxxxxx> > --- > > V3: > - The inode->i_count couldn't be correctly indicate that whether the > file is opened or not. > > V2: > - If the dentry was released and inode is evicted such as by dropping > the caches, it will allocate a new dentry, which is also unhashed. > > fs/ceph/export.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/fs/ceph/export.c b/fs/ceph/export.c > index 0ebf2bd93055..8559990a59a5 100644 > --- a/fs/ceph/export.c > +++ b/fs/ceph/export.c > @@ -182,6 +182,7 @@ struct inode *ceph_lookup_inode(struct super_block *sb, u64 ino) > static struct dentry *__fh_to_dentry(struct super_block *sb, u64 ino) > { > struct inode *inode = __lookup_inode(sb, ino); > + struct ceph_inode_info *ci = ceph_inode(inode); > int err; > > if (IS_ERR(inode)) > @@ -193,7 +194,7 @@ static struct dentry *__fh_to_dentry(struct super_block *sb, u64 ino) > return ERR_PTR(err); > } > /* -ESTALE if inode as been unlinked and no file is open */ > - if ((inode->i_nlink == 0) && (atomic_read(&inode->i_count) == 1)) { > + if ((inode->i_nlink == 0) && !__ceph_is_file_opened(ci)) { > iput(inode); > return ERR_PTR(-ESTALE); > } Looks reasonable Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
