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| author | Thomas Gleixner <tglx@linutronix.de> | 2009-07-19 08:44:27 -0500 |
|---|---|---|
| committer | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2016-12-23 17:14:37 +0100 |
| commit | db10656a8bbebda2cd7054c1ae250b3a43031d78 (patch) | |
| tree | a85ff41935921dc093ee2469d448b926261270dc /fs | |
| parent | 13a29b9e4e6490559e49653e60ebf56d946c15ba (diff) | |
| download | linux-rt-db10656a8bbebda2cd7054c1ae250b3a43031d78.tar.gz | |
fs: namespace preemption fix
On RT we cannot loop with preemption disabled here as
mnt_make_readonly() might have been preempted. We can safely enable
preemption while waiting for MNT_WRITE_HOLD to be cleared. Safe on !RT
as well.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/namespace.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index e6c234b1a645..e2d82ac61796 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -356,8 +356,11 @@ int __mnt_want_write(struct vfsmount *m) * incremented count after it has set MNT_WRITE_HOLD. */ smp_mb(); - while (ACCESS_ONCE(mnt->mnt.mnt_flags) & MNT_WRITE_HOLD) + while (ACCESS_ONCE(mnt->mnt.mnt_flags) & MNT_WRITE_HOLD) { + preempt_enable(); cpu_relax(); + preempt_disable(); + } /* * After the slowpath clears MNT_WRITE_HOLD, mnt_is_readonly will * be set to match its requirements. So we must not load that until |