[PATCH 12/23] vfs: Teach fcntl to use file_hotplug_lock

Eric W. Biederman
2009-06-01T21:54:33Z

From: Eric W. Biederman <ebiederm@maxwell.arastra.com>

Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
---
fs/fcntl.c | 28 +++++++++++++++++++---------
1 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/fs/fcntl.c b/fs/fcntl.c
index cc8e4de..05d8961 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -344,14 +344,19 @@ SYSCALL_DEFINE3(fcntl, unsigned int, fd, unsigned int, cmd, unsigned long, arg)
if (!filp)
goto out;

+ err = -EIO;
+ if (!file_hotplug_read_trylock(filp))
+ goto out_fput;
+
err = security_file_fcntl(filp, cmd, arg);
- if (err) {
- fput(filp);
- return err;
- }
+ if (err)
+ goto out_unlock;

err = do_fcntl(fd, cmd, arg, filp);

+out_unlock:
+ file_hotplug_read_unlock(filp);
+out_fput:
fput(filp);
out:
return err;
@@ -369,13 +374,15 @@ SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd,
if (!filp)
goto out;

+ err = -EIO;
+ if (!file_hotplug_read_trylock(filp))
+ goto out_fput;
+
err = security_file_fcntl(filp, cmd, arg);
- if (err) {
- fput(filp);
- return err;
- }
+ if (err)
+ goto out_unlock;
+
err = -EBADF;
-
switch (cmd) {
case F_GETLK64:
err = fcntl_getlk64(filp, (struct flock64 __user *) arg);
@@ -389,6 +396,9 @@ SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd,
err = do_fcntl(fd, cmd, arg, filp);
break;
}
+out_unlock:
+ file_hotplug_read_unlock(filp);
+out_fput:
fput(filp);
out:
return err;
--
1.6.3.1.54.g99dd.dirty