Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
simplify the callers of mnt_unhold_writers()
The logics in cleanup on failure in mount_setattr_prepare() is simplified
by having the mnt_hold_writers() failure followed by advancing m to the
next node in the tree before leaving the loop.
And since all calls are preceded by the same check that flag has been set
and the function is inlined, let's just shift the check into it.
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
+10
-24
+10
-24
fs/namespace.c
+10
-24
fs/namespace.c
···
714
714
* Stop preventing write access to @mnt allowing callers to gain write access
715
715
* to @mnt again.
716
716
*
717
-
* This function can only be called after a successful call to
718
-
* mnt_hold_writers().
717
+
* This function can only be called after a call to mnt_hold_writers().
719
718
*
720
719
* Context: This function expects lock_mount_hash() to be held.
721
720
*/
722
721
static inline void mnt_unhold_writers(struct mount *mnt)
723
722
{
723
+
if (!(mnt->mnt_flags & MNT_WRITE_HOLD))
724
+
return;
724
725
/*
725
726
* MNT_READONLY must become visible before ~MNT_WRITE_HOLD, so writers
726
727
* that become unheld will see MNT_READONLY.
···
4769
4768
4770
4769
if (!mnt_allow_writers(kattr, m)) {
4771
4770
err = mnt_hold_writers(m);
4772
-
if (err)
4771
+
if (err) {
4772
+
m = next_mnt(m, mnt);
4773
4773
break;
4774
+
}
4774
4775
}
4775
4776
4776
4777
if (!(kattr->kflags & MOUNT_KATTR_RECURSE))
···
4780
4777
}
4781
4778
4782
4779
if (err) {
4783
-
struct mount *p;
4784
-
4785
-
/*
4786
-
* If we had to call mnt_hold_writers() MNT_WRITE_HOLD will
4787
-
* be set in @mnt_flags. The loop unsets MNT_WRITE_HOLD for all
4788
-
* mounts and needs to take care to include the first mount.
4789
-
*/
4790
-
for (p = mnt; p; p = next_mnt(p, mnt)) {
4791
-
/* If we had to hold writers unblock them. */
4792
-
if (p->mnt.mnt_flags & MNT_WRITE_HOLD)
4793
-
mnt_unhold_writers(p);
4794
-
4795
-
/*
4796
-
* We're done once the first mount we changed got
4797
-
* MNT_WRITE_HOLD unset.
4798
-
*/
4799
-
if (p == m)
4800
-
break;
4801
-
}
4780
+
/* undo all mnt_hold_writers() we'd done */
4781
+
for (struct mount *p = mnt; p != m; p = next_mnt(p, mnt))
4782
+
mnt_unhold_writers(p);
4802
4783
}
4803
4784
return err;
4804
4785
}
···
4813
4826
WRITE_ONCE(m->mnt.mnt_flags, flags);
4814
4827
4815
4828
/* If we had to hold writers unblock them. */
4816
-
if (m->mnt.mnt_flags & MNT_WRITE_HOLD)
4817
-
mnt_unhold_writers(m);
4829
+
mnt_unhold_writers(m);
4818
4830
4819
4831
if (kattr->propagation)
4820
4832
change_mnt_propagation(m, kattr->propagation);