Message ID | 20190523081345.20410-6-zyan@redhat.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | [1/8] ceph: fix error handling in ceph_get_caps() | expand |
On Thu, 2019-05-23 at 16:13 +0800, Yan, Zheng wrote: > Signed-off-by: "Yan, Zheng" <zyan@redhat.com> > --- > fs/ceph/mds_client.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c > index 60e8ddbdfdc5..870754e9d572 100644 > --- a/fs/ceph/mds_client.c > +++ b/fs/ceph/mds_client.c > @@ -913,7 +913,7 @@ static int __choose_mds(struct ceph_mds_client *mdsc, > struct inode *dir; > > rcu_read_lock(); > - parent = req->r_dentry->d_parent; > + parent = READ_ONCE(req->r_dentry->d_parent); Can we use rcu_dereference() instead? > dir = req->r_parent ? : d_inode_rcu(parent); > > if (!dir || dir->i_sb != mdsc->fsc->sb) { > @@ -2131,8 +2131,8 @@ char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *pbase, > if (inode && ceph_snap(inode) == CEPH_SNAPDIR) { > dout("build_path path+%d: %p SNAPDIR\n", > pos, temp); > - } else if (stop_on_nosnap && inode && dentry != temp && > - ceph_snap(inode) == CEPH_NOSNAP) { > + } else if (stop_on_nosnap && dentry != temp && > + inode && ceph_snap(inode) == CEPH_NOSNAP) { ^^^ Unrelated delta? > spin_unlock(&temp->d_lock); > pos++; /* get rid of any prepended '/' */ > break; > @@ -2145,7 +2145,7 @@ char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *pbase, > memcpy(path + pos, temp->d_name.name, temp->d_name.len); > } > spin_unlock(&temp->d_lock); > - temp = temp->d_parent; > + temp = READ_ONCE(temp->d_parent); Better to use rcu_dereference() here. > > /* Are we at the root? */ > if (IS_ROOT(temp))
On Tue, May 28, 2019 at 9:57 PM Jeff Layton <jlayton@redhat.com> wrote: > > On Thu, 2019-05-23 at 16:13 +0800, Yan, Zheng wrote: > > Signed-off-by: "Yan, Zheng" <zyan@redhat.com> > > --- > > fs/ceph/mds_client.c | 8 ++++---- > > 1 file changed, 4 insertions(+), 4 deletions(-) > > > > diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c > > index 60e8ddbdfdc5..870754e9d572 100644 > > --- a/fs/ceph/mds_client.c > > +++ b/fs/ceph/mds_client.c > > @@ -913,7 +913,7 @@ static int __choose_mds(struct ceph_mds_client *mdsc, > > struct inode *dir; > > > > rcu_read_lock(); > > - parent = req->r_dentry->d_parent; > > + parent = READ_ONCE(req->r_dentry->d_parent); > > Can we use rcu_dereference() instead? > d_parent has no __rcu mark. It will cause sparse warning. Regards Yan, Zheng > > dir = req->r_parent ? : d_inode_rcu(parent); > > > > if (!dir || dir->i_sb != mdsc->fsc->sb) { > > @@ -2131,8 +2131,8 @@ char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *pbase, > > if (inode && ceph_snap(inode) == CEPH_SNAPDIR) { > > dout("build_path path+%d: %p SNAPDIR\n", > > pos, temp); > > - } else if (stop_on_nosnap && inode && dentry != temp && > > - ceph_snap(inode) == CEPH_NOSNAP) { > > + } else if (stop_on_nosnap && dentry != temp && > > + inode && ceph_snap(inode) == CEPH_NOSNAP) { > > ^^^ Unrelated delta? > > > spin_unlock(&temp->d_lock); > > pos++; /* get rid of any prepended '/' */ > > break; > > @@ -2145,7 +2145,7 @@ char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *pbase, > > memcpy(path + pos, temp->d_name.name, temp->d_name.len); > > } > > spin_unlock(&temp->d_lock); > > - temp = temp->d_parent; > > + temp = READ_ONCE(temp->d_parent); > > Better to use rcu_dereference() here. > > > > > /* Are we at the root? */ > > if (IS_ROOT(temp)) > > -- > Jeff Layton <jlayton@redhat.com> >
On Wed, 2019-05-29 at 10:17 +0800, Yan, Zheng wrote: > On Tue, May 28, 2019 at 9:57 PM Jeff Layton <jlayton@redhat.com> wrote: > > On Thu, 2019-05-23 at 16:13 +0800, Yan, Zheng wrote: > > > Signed-off-by: "Yan, Zheng" <zyan@redhat.com> > > > --- > > > fs/ceph/mds_client.c | 8 ++++---- > > > 1 file changed, 4 insertions(+), 4 deletions(-) > > > > > > diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c > > > index 60e8ddbdfdc5..870754e9d572 100644 > > > --- a/fs/ceph/mds_client.c > > > +++ b/fs/ceph/mds_client.c > > > @@ -913,7 +913,7 @@ static int __choose_mds(struct ceph_mds_client *mdsc, > > > struct inode *dir; > > > > > > rcu_read_lock(); > > > - parent = req->r_dentry->d_parent; > > > + parent = READ_ONCE(req->r_dentry->d_parent); > > > > Can we use rcu_dereference() instead? > > > > d_parent has no __rcu mark. It will cause sparse warning. > > Regards > Yan, Zheng > Good point. > > > dir = req->r_parent ? : d_inode_rcu(parent); > > > > > > if (!dir || dir->i_sb != mdsc->fsc->sb) { > > > @@ -2131,8 +2131,8 @@ char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *pbase, > > > if (inode && ceph_snap(inode) == CEPH_SNAPDIR) { > > > dout("build_path path+%d: %p SNAPDIR\n", > > > pos, temp); > > > - } else if (stop_on_nosnap && inode && dentry != temp && > > > - ceph_snap(inode) == CEPH_NOSNAP) { > > > + } else if (stop_on_nosnap && dentry != temp && > > > + inode && ceph_snap(inode) == CEPH_NOSNAP) { > > > > ^^^ Unrelated delta? > > > > > spin_unlock(&temp->d_lock); > > > pos++; /* get rid of any prepended '/' */ > > > break; > > > @@ -2145,7 +2145,7 @@ char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *pbase, > > > memcpy(path + pos, temp->d_name.name, temp->d_name.len); > > > } > > > spin_unlock(&temp->d_lock); > > > - temp = temp->d_parent; > > > + temp = READ_ONCE(temp->d_parent); > > > > Better to use rcu_dereference() here. > > > > > /* Are we at the root? */ > > > if (IS_ROOT(temp)) > > Reviewed-by: Jeff Layton <jlayton@redhat.com>
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index 60e8ddbdfdc5..870754e9d572 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -913,7 +913,7 @@ static int __choose_mds(struct ceph_mds_client *mdsc, struct inode *dir; rcu_read_lock(); - parent = req->r_dentry->d_parent; + parent = READ_ONCE(req->r_dentry->d_parent); dir = req->r_parent ? : d_inode_rcu(parent); if (!dir || dir->i_sb != mdsc->fsc->sb) { @@ -2131,8 +2131,8 @@ char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *pbase, if (inode && ceph_snap(inode) == CEPH_SNAPDIR) { dout("build_path path+%d: %p SNAPDIR\n", pos, temp); - } else if (stop_on_nosnap && inode && dentry != temp && - ceph_snap(inode) == CEPH_NOSNAP) { + } else if (stop_on_nosnap && dentry != temp && + inode && ceph_snap(inode) == CEPH_NOSNAP) { spin_unlock(&temp->d_lock); pos++; /* get rid of any prepended '/' */ break; @@ -2145,7 +2145,7 @@ char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *pbase, memcpy(path + pos, temp->d_name.name, temp->d_name.len); } spin_unlock(&temp->d_lock); - temp = temp->d_parent; + temp = READ_ONCE(temp->d_parent); /* Are we at the root? */ if (IS_ROOT(temp))
Signed-off-by: "Yan, Zheng" <zyan@redhat.com> --- fs/ceph/mds_client.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)