aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorThomas Gleixner <tglx@linutronix.de>2012-03-01 16:12:47 +0100
committerSteven Rostedt <rostedt@rostedt.homelinux.com>2013-02-14 12:34:33 -0500
commit2dd4f840e08d65146327f9e0229f837c3ba74e68 (patch)
treee8c14516c00370399f37548f9f8659205d9c9a52
parentc9cabd78a6f55b95a4d0e7f886926d3bed3dfa35 (diff)
fs: Protect open coded isize seqcount
A writer might be preempted in the write side critical section on RT. Disable preemption to avoid endless spinning of a preempting reader. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable-rt@vger.kernel.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
-rw-r--r--include/linux/fs.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/fs.h b/include/linux/fs.h
index adc132e0a585..aceb8af96c21 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -880,9 +880,11 @@ static inline loff_t i_size_read(const struct inode *inode)
static inline void i_size_write(struct inode *inode, loff_t i_size)
{
#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
+ preempt_disable_rt();
write_seqcount_begin(&inode->i_size_seqcount);
inode->i_size = i_size;
write_seqcount_end(&inode->i_size_seqcount);
+ preempt_enable_rt();
#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT)
preempt_disable();
inode->i_size = i_size;