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| author | Thomas Gleixner <tglx@linutronix.de> | 2009-07-19 13:44:27 (GMT) |
|---|---|---|
| committer | Scott Wood <scottwood@freescale.com> | 2014-04-10 00:19:36 (GMT) |
| commit | de92ac57a46708314fd323475d2351ad485a8156 (patch) | |
| tree | 66baf96ee65aa11788d29ab508bcd64425559e56 /fs | |
| parent | 83e3597c4eba0a2f56c3f296bad875d163929cbd (diff) | |
| download | linux-fsl-qoriq-de92ac57a46708314fd323475d2351ad485a8156.tar.xz | |
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 84447db..6ed0fb1 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -315,8 +315,11 @@ 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 |