Since FL_FILP_PRIVATE locks have different semantics on close, we can't
merge them with "normal" locks or with other FL_FILP_PRIVATE locks that
were acquired on different file descriptors. Consolidate the logic that
determines this into its own function.
Signed-off-by: Jeff Layton <jlay...@redhat.com>
---
fs/locks.c | 38 +++++++++++++++++++++++++++++++++++---
1 file changed, 35 insertions(+), 3 deletions(-)
diff --git a/fs/locks.c b/fs/locks.c
index 7186b9a..3bde157 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -934,6 +934,39 @@ out:
return error;
}
+/**
+ * posix_locks_mergeable - are two posix locks able to be merged?
+ * @fl1: first posix lock
+ * @fl2: second posix lock
+ *
+ * Determine whether two posix locks are potentially able to be merged. If
+ * they are of different types or have different settings of FL_FILP_PRIVATE
+ * then they cannot be. Ditto if they are FL_FILP_PRIVATE locks and are
+ * associated with different file descriptors.
+ */
+static bool
+posix_locks_mergeable(struct file_lock *fl1, struct file_lock *fl2)
+{
+ unsigned int p1, p2;
+
+ /* Different types are not mergeable */
+ if (fl1->fl_type != fl2->fl_type)
+ return false;
+
+ p1 = IS_PRIVATE(fl1);
+ p2 = IS_PRIVATE(fl2);
+
+ /* Different settings of FL_FILP_PRIVATE aren't mergeable */
+ if (p1 != p2)
+ return false;
+
+ /* When FL_FILP_PRIVATE is set, fl_file must be same */
+ if (p1 && fl1->fl_file != fl2->fl_file)
+ return false;
+
+ return true;
+}
+
static int __posix_lock_file(struct inode *inode, struct file_lock *request,
struct file_lock *conflock)
{
struct file_lock *fl;
@@ -1018,9 +1051,8 @@ static int __posix_lock_file(struct inode *inode, struct
file_lock *request, str
request->fl_file != fl->fl_file)
goto next_lock;
- /* Detect adjacent or overlapping regions (if same lock type)
- */
- if (request->fl_type == fl->fl_type) {
+ /* Detect adjacent or overlapping regions (if same lock type) */
+ if (posix_locks_mergeable(fl, request)) {
/* In all comparisons of start vs end, use
* "start - 1" rather than "end + 1". If end
* is OFFSET_MAX, end + 1 will become negative.
--
1.8.3.1
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