Fix Connectathon locking test failure

 We currently fail Connectathon test 6.10 in the case of 32-bit locks due
 to incorrect error checking.
 Also add support for l->l_len < 0 to 64-bit locks.

 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 25 insertions, 17 deletions

diff --git a/fs/locks.c b/fs/locks.c
index 7eb1d77b9204..a1e8b2248014 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -316,21 +316,22 @@ static int flock_to_posix_lock(struct file *filp, struct file_lock *fl,
         /* POSIX-1996 leaves the case l->l_len < 0 undefined;
            POSIX-2001 defines it. */
         start += l->l_start;
-        end = start + l->l_len - 1;
-        if (l->l_len < 0) {
+        if (start < 0)
+                return -EINVAL;
+        fl->fl_end = OFFSET_MAX;
+        if (l->l_len > 0) {
+                end = start + l->l_len - 1;
+                fl->fl_end = end;
+        } else if (l->l_len < 0) {
                 end = start - 1;
+                fl->fl_end = end;
                 start += l->l_len;
+                if (start < 0)
+                        return -EINVAL;
         }
-
-        if (start < 0)
-                return -EINVAL;
-        if (l->l_len > 0 && end < 0)
-                return -EOVERFLOW;
-
         fl->fl_start = start;   /* we record the absolute position */
-        fl->fl_end = end;
-        if (l->l_len == 0)
-                fl->fl_end = OFFSET_MAX;
+        if (fl->fl_end < fl->fl_start)
+                return -EOVERFLOW;
         
         fl->fl_owner = current->files;
         fl->fl_pid = current->tgid;
@@ -362,14 +363,21 @@ static int flock64_to_posix_lock(struct file *filp, struct file_lock *fl,
                 return -EINVAL;
         }
 
-        if (((start += l->l_start) < 0) || (l->l_len < 0))
+        start += l->l_start;
+        if (start < 0)
                 return -EINVAL;
-        fl->fl_end = start + l->l_len - 1;
-        if (l->l_len > 0 && fl->fl_end < 0)
-                return -EOVERFLOW;
+        fl->fl_end = OFFSET_MAX;
+        if (l->l_len > 0) {
+                fl->fl_end = start + l->l_len - 1;
+        } else if (l->l_len < 0) {
+                fl->fl_end = start - 1;
+                start += l->l_len;
+                if (start < 0)
+                        return -EINVAL;
+        }
         fl->fl_start = start;   /* we record the absolute position */
-        if (l->l_len == 0)
-                fl->fl_end = OFFSET_MAX;
+        if (fl->fl_end < fl->fl_start)
+                return -EOVERFLOW;
         
         fl->fl_owner = current->files;
         fl->fl_pid = current->tgid;