[RFC PATCH v2 4/5] locks: show private lock types in /proc/locks

[Jeff Layton]

Show "private" locks in /proc/locks with a 'P' suffix. This does mean
that we need to widen the column by one character.

Also, tighten up the check in locks_remove_filp() to ensure that only
IS_FILP_PVT locks are removed there.

Signed-off-by: Jeff Layton <jlayton at redhat.com>
---
 fs/locks.c         | 15 +++++++++++----
 include/linux/fs.h |  1 +
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/fs/locks.c b/fs/locks.c
index 3b278a6..d5fb853 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -135,6 +135,7 @@
 #define IS_POSIX(fl)	(fl->fl_flags & FL_POSIX)
 #define IS_FLOCK(fl)	(fl->fl_flags & FL_FLOCK)
 #define IS_LEASE(fl)	(fl->fl_flags & (FL_LEASE|FL_DELEG))
+#define IS_FILP_PVT(fl)	(fl->fl_flags & FL_FILP_PRIVATE)
 
 static bool lease_breaking(struct file_lock *fl)
 {
@@ -357,14 +358,17 @@ static int posix_assign_type(struct file_lock *fl, long type)
 	case F_RDLCKP:
 		type = F_RDLCK;
 		fl->fl_owner = (fl_owner_t)fl->fl_file;
+		fl->fl_flags |= FL_FILP_PRIVATE;
 		break;
 	case F_WRLCKP:
 		type = F_WRLCK;
 		fl->fl_owner = (fl_owner_t)fl->fl_file;
+		fl->fl_flags |= FL_FILP_PRIVATE;
 		break;
 	case F_UNLCKP:
 		type = F_UNLCK;
 		fl->fl_owner = (fl_owner_t)fl->fl_file;
+		fl->fl_flags |= FL_FILP_PRIVATE;
 		break;
 	}
 
@@ -2245,7 +2249,8 @@ void locks_remove_filp(struct file *filp)
 
 	while ((fl = *before) != NULL) {
 		if (fl->fl_file == filp) {
-			if (IS_FLOCK(fl) || IS_POSIX(fl)) {
+			if (IS_FLOCK(fl) ||
+			    (IS_POSIX(fl) && IS_FILP_PVT(fl))) {
 				locks_delete_lock(before);
 				continue;
 			}
@@ -2345,13 +2350,15 @@ static void lock_get_status(struct seq_file *f, struct file_lock *fl,
 		seq_printf(f, "UNKNOWN UNKNOWN  ");
 	}
 	if (fl->fl_type & LOCK_MAND) {
-		seq_printf(f, "%s ",
+		seq_printf(f, "%s  ",
 			       (fl->fl_type & LOCK_READ)
 			       ? (fl->fl_type & LOCK_WRITE) ? "RW   " : "READ "
 			       : (fl->fl_type & LOCK_WRITE) ? "WRITE" : "NONE ");
+	} else if (IS_FILP_PVT(fl)) {
+		seq_printf(f, "%s ", fl->fl_type == F_WRLCK ?  "WRITEP" : "READP ");
 	} else {
-		seq_printf(f, "%s ",
-			       (lease_breaking(fl))
+		seq_printf(f, "%s  ",
+			       lease_breaking(fl)
 			       ? (fl->fl_type == F_UNLCK) ? "UNLCK" : "READ "
 			       : (fl->fl_type == F_WRLCK) ? "WRITE" : "READ ");
 	}
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 2d890ce..9890bac 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -888,6 +888,7 @@ static inline int file_check_writeable(struct file *filp)
 #define FL_SLEEP	128	/* A blocking lock */
 #define FL_DOWNGRADE_PENDING	256 /* Lease is being downgraded */
 #define FL_UNLOCK_PENDING	512 /* Lease is being broken */
+#define FL_FILP_PRIVATE	1024	/* lock is private to the filp */
 
 /*
  * Special return value from posix_lock_file() and vfs_lock_file() for
-- 
1.8.3.1