Messages in this thread Patch in this message | | | Date | Tue, 06 Mar 2012 11:16:53 -0500 | From | Steven Rostedt <> | Subject | [PATCH RT 17/25][RFC 3.0.23-rt39-rc1] fs: Protect open coded isize seqcount |
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From: Thomas Gleixner <tglx@linutronix.de>
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> --- include/linux/fs.h | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-)
diff --git a/include/linux/fs.h b/include/linux/fs.h index 9c85217..c7984a5 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -876,9 +876,11 @@ 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; -- 1.7.8.3
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