From: Olaf Kirch <okir@suse.de>

[deliverable/linux.git] / fs / locks.c

diff --git a/fs/locks.c b/fs/locks.c
index c2c09b4798d606b4bc9e5d56a518beef021543f3..7eb1d77b9204deccce359d4b2f9f1e9ffcb954ab 100644 (file)
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -124,6 +124,7 @@
 #include <linux/smp_lock.h>
 #include <linux/syscalls.h>
 #include <linux/time.h>
+#include <linux/rcupdate.h>
 
 #include <asm/semaphore.h>
 #include <asm/uaccess.h>
@@ -828,12 +829,16 @@ static int __posix_lock_file(struct inode *inode, struct file_lock *request)
                /* Detect adjacent or overlapping regions (if same lock type)
                 */
                if (request->fl_type == fl->fl_type) {
+                       /* In all comparisons of start vs end, use
+                        * "start - 1" rather than "end + 1". If end
+                        * is OFFSET_MAX, end + 1 will become negative.
+                        */
                        if (fl->fl_end < request->fl_start - 1)
                                goto next_lock;
                        /* If the next lock in the list has entirely bigger
                         * addresses than the new one, insert the lock here.
                         */
-                       if (fl->fl_start > request->fl_end + 1)
+                       if (fl->fl_start - 1 > request->fl_end)
                                break;
 
                        /* If we come here, the new and old lock are of the
@@ -2205,6 +2210,7 @@ void steal_locks(fl_owner_t from)
 
        lock_kernel();
        j = 0;
+       rcu_read_lock();
        fdt = files_fdtable(files);
        for (;;) {
                unsigned long set;
@@ -2222,6 +2228,7 @@ void steal_locks(fl_owner_t from)
                        set >>= 1;
                }
        }
+       rcu_read_unlock();
        unlock_kernel();
 }
 EXPORT_SYMBOL(steal_locks);