> On 2 May 2017, at 21:02, Luis Henriques <lhenriques@xxxxxxxx> wrote: > > On Tue, May 02, 2017 at 07:19:06PM +0800, Yan, Zheng wrote: > [...] >> Thank you for the patch. but it does not work because ceph_set_acl() >> calls ceph_setattr() directly. I think we need to introduce >> __ceph_setattr() and make ceph_set_acl() call __ceph_setattr() > > Ah, of course! Maybe something like this: > > > From a6751ca41e6096638b75bf9d066338571399e8b4 Mon Sep 17 00:00:00 2001 > From: "Yan, Zheng" <zyan@xxxxxxxxxx> > Date: Wed, 19 Apr 2017 10:01:48 +0800 > Subject: [PATCH] ceph: fix recursion between ceph_set_acl() and > __ceph_setattr() > > commit 8179a101eb5f4ef0ac9a915fcea9a9d3109efa90 upstream. > > ceph_set_acl() calls __ceph_setattr() if the setacl operation needs > to modify inode's i_mode. __ceph_setattr() updates inode's i_mode, > then calls posix_acl_chmod(). > > The problem is that __ceph_setattr() calls posix_acl_chmod() before > sending the setattr request. The get_acl() call in posix_acl_chmod() > can trigger a getxattr request. The reply of the getxattr request > can restore inode's i_mode to its old value. The set_acl() call in > posix_acl_chmod() sees old value of inode's i_mode, so it calls > __ceph_setattr() again. > > Cc: stable@xxxxxxxxxxxxxxx # needs backporting for < 4.9 > Link: http://tracker.ceph.com/issues/19688 > Reported-by: Jerry Lee <leisurelysw24@xxxxxxxxx> > Signed-off-by: "Yan, Zheng" <zyan@xxxxxxxxxx> > Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx> > Tested-by: Luis Henriques <lhenriques@xxxxxxxx> > Signed-off-by: Ilya Dryomov <idryomov@xxxxxxxxx> > [luis: introduce __ceph_setattr() and make ceph_set_acl() call it, as > suggested by Yan.] > Signed-off-by: Luis Henriques <lhenriques@xxxxxxxx> > --- > fs/ceph/acl.c | 4 ++-- > fs/ceph/inode.c | 27 ++++++++++++++++----------- > fs/ceph/super.h | 1 + > 3 files changed, 19 insertions(+), 13 deletions(-) > > diff --git a/fs/ceph/acl.c b/fs/ceph/acl.c > index 4d8caeb94a11..bdb9c94335f1 100644 > --- a/fs/ceph/acl.c > +++ b/fs/ceph/acl.c > @@ -128,7 +128,7 @@ int ceph_set_acl(struct inode *inode, struct posix_acl *acl, int type) > if (new_mode != old_mode) { > newattrs.ia_mode = new_mode; > newattrs.ia_valid = ATTR_MODE; > - ret = ceph_setattr(dentry, &newattrs); > + ret = __ceph_setattr(dentry, &newattrs); > if (ret) > goto out_dput; > } > @@ -138,7 +138,7 @@ int ceph_set_acl(struct inode *inode, struct posix_acl *acl, int type) > if (new_mode != old_mode) { > newattrs.ia_mode = old_mode; > newattrs.ia_valid = ATTR_MODE; > - ceph_setattr(dentry, &newattrs); > + __ceph_setattr(dentry, &newattrs); > } > goto out_dput; > } > diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c > index d98536c8abfc..9f0d99094cc1 100644 > --- a/fs/ceph/inode.c > +++ b/fs/ceph/inode.c > @@ -1773,7 +1773,7 @@ static const struct inode_operations ceph_symlink_iops = { > /* > * setattr > */ > -int ceph_setattr(struct dentry *dentry, struct iattr *attr) > +int __ceph_setattr(struct dentry *dentry, struct iattr *attr) > { > struct inode *inode = d_inode(dentry); > struct ceph_inode_info *ci = ceph_inode(inode); > @@ -1975,11 +1975,6 @@ int ceph_setattr(struct dentry *dentry, struct iattr *attr) > if (inode_dirty_flags) > __mark_inode_dirty(inode, inode_dirty_flags); > > - if (ia_valid & ATTR_MODE) { > - err = posix_acl_chmod(inode, attr->ia_mode); > - if (err) > - goto out_put; > - } > > if (mask) { > req->r_inode = inode; > @@ -1993,13 +1988,23 @@ int ceph_setattr(struct dentry *dentry, struct iattr *attr) > ceph_cap_string(dirtied), mask); > > ceph_mdsc_put_request(req); > - if (mask & CEPH_SETATTR_SIZE) > - __ceph_do_pending_vmtruncate(inode); > ceph_free_cap_flush(prealloc_cf); > + > + if (err >= 0 && (mask & CEPH_SETATTR_SIZE)) > + __ceph_do_pending_vmtruncate(inode); > + > return err; > -out_put: > - ceph_mdsc_put_request(req); > - ceph_free_cap_flush(prealloc_cf); > +} > + > +int ceph_setattr(struct dentry *dentry, struct iattr *attr) > +{ > + int err; > + > + err = __ceph_setattr(dentry, attr); > + > + if (err >= 0 && (attr->ia_valid & ATTR_MODE)) > + err = posix_acl_chmod(d_inode(dentry), attr->ia_mode); > + > return err; > } > > diff --git a/fs/ceph/super.h b/fs/ceph/super.h > index 75b7d125ce66..8c8cb8fe3d32 100644 > --- a/fs/ceph/super.h > +++ b/fs/ceph/super.h > @@ -788,6 +788,7 @@ static inline int ceph_do_getattr(struct inode *inode, int mask, bool force) > return __ceph_do_getattr(inode, NULL, mask, force); > } > extern int ceph_permission(struct inode *inode, int mask); > +extern int __ceph_setattr(struct dentry *dentry, struct iattr *attr); > extern int ceph_setattr(struct dentry *dentry, struct iattr *attr); > extern int ceph_getattr(struct vfsmount *mnt, struct dentry *dentry, > struct kstat *stat); Reviewed-by: “Yan, Zheng” <zyan@xxxxxxxxxx>