| Message ID | 20200511082512.4375-1-zyan@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | ceph: properly wake up cap waiter after releasing revoked caps | expand |
On Mon, 2020-05-11 at 16:25 +0800, Yan, Zheng wrote: > arg->wake can never be true. the bug was introduced by commit > 0c4b255369bcf "ceph: reorganize __send_cap for less spinlock abuse" > > Signed-off-by: "Yan, Zheng" <zyan@redhat.com> > --- > fs/ceph/caps.c | 13 ++++++------- > 1 file changed, 6 insertions(+), 7 deletions(-) > > diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c > index b3e65c89ba6e..a2a2cda117e0 100644 > --- a/fs/ceph/caps.c > +++ b/fs/ceph/caps.c > @@ -1376,6 +1376,12 @@ static void __prep_cap(struct cap_msg_args *arg, struct ceph_cap *cap, > ci->i_ceph_flags &= ~CEPH_I_FLUSH; > > cap->issued &= retain; /* drop bits we don't want */ > + /* > + * Wake up any waiters on wanted -> needed transition. This is due to > + * the weird transition from buffered to sync IO... we need to flush > + * dirty pages _before_ allowing sync writes to avoid reordering. > + */ > + arg->wake = cap->implemented & ~cap->issued; > cap->implemented &= cap->issued | used; > cap->mds_wanted = want; > > @@ -1439,13 +1445,6 @@ static void __prep_cap(struct cap_msg_args *arg, struct ceph_cap *cap, > } > } > arg->flags = flags; > - > - /* > - * Wake up any waiters on wanted -> needed transition. This is due to > - * the weird transition from buffered to sync IO... we need to flush > - * dirty pages _before_ allowing sync writes to avoid reordering. > - */ > - arg->wake = cap->implemented & ~cap->issued; > } > > /* Good catch! Merged (with a small revision to the commit message).
diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c index b3e65c89ba6e..a2a2cda117e0 100644 --- a/fs/ceph/caps.c +++ b/fs/ceph/caps.c @@ -1376,6 +1376,12 @@ static void __prep_cap(struct cap_msg_args *arg, struct ceph_cap *cap, ci->i_ceph_flags &= ~CEPH_I_FLUSH; cap->issued &= retain; /* drop bits we don't want */ + /* + * Wake up any waiters on wanted -> needed transition. This is due to + * the weird transition from buffered to sync IO... we need to flush + * dirty pages _before_ allowing sync writes to avoid reordering. + */ + arg->wake = cap->implemented & ~cap->issued; cap->implemented &= cap->issued | used; cap->mds_wanted = want; @@ -1439,13 +1445,6 @@ static void __prep_cap(struct cap_msg_args *arg, struct ceph_cap *cap, } } arg->flags = flags; - - /* - * Wake up any waiters on wanted -> needed transition. This is due to - * the weird transition from buffered to sync IO... we need to flush - * dirty pages _before_ allowing sync writes to avoid reordering. - */ - arg->wake = cap->implemented & ~cap->issued; } /*
arg->wake can never be true. the bug was introduced by commit 0c4b255369bcf "ceph: reorganize __send_cap for less spinlock abuse" Signed-off-by: "Yan, Zheng" <zyan@redhat.com> --- fs/ceph/caps.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-)