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authorJonathan Corbet <corbet@lwn.net>2009-02-06 15:25:24 -0700
committerJonathan Corbet <corbet@lwn.net>2009-03-16 08:32:27 -0600
commitdb1dd4d376134eba0e08af523b61cc566a4ea1cd (patch)
tree8882c673abbaa5713511b7046493fa862b9140d1 /drivers/char/tty_io.c
parent684999149002dd046269666a390458e0acb38280 (diff)
Use f_lock to protect f_flags
Traditionally, changes to struct file->f_flags have been done under BKL protection, or with no protection at all. This patch causes all f_flags changes after file open/creation time to be done under protection of f_lock. This allows the removal of some BKL usage and fixes a number of longstanding (if microscopic) races. Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Diffstat (limited to 'drivers/char/tty_io.c')
-rw-r--r--drivers/char/tty_io.c5
1 files changed, 2 insertions, 3 deletions
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index bc84e125c6b..224f271d8cb 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -2162,13 +2162,12 @@ static int fionbio(struct file *file, int __user *p)
if (get_user(nonblock, p))
return -EFAULT;
- /* file->f_flags is still BKL protected in the fs layer - vomit */
- lock_kernel();
+ spin_lock(&file->f_lock);
if (nonblock)
file->f_flags |= O_NONBLOCK;
else
file->f_flags &= ~O_NONBLOCK;
- unlock_kernel();
+ spin_unlock(&file->f_lock);
return 0;
}