filelock: add some new helper functions

In later patches we're going to embed some common fields into a new
structure inside struct file_lock. Smooth the transition by adding some
new helper functions, and converting the core file locking code to use
them.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/r/20240131-flsplit-v3-4-c6129007ee8d@kernel.org
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/fs/locks.c b/fs/locks.c
index 1eceaa56e47f98b58b5e0ad75a06967c2cfc7a25..149070fd3b66153d8814c44d29e88a33ad017c77 100644 (file)
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -674,7 +674,7 @@ static void __locks_wake_up_blocks(struct file_lock *blocker)
                if (waiter->fl_lmops && waiter->fl_lmops->lm_notify)
                        waiter->fl_lmops->lm_notify(waiter);
                else
-                       wake_up(&waiter->fl_wait);
+                       locks_wake_up(waiter);
 
                /*
                 * The setting of fl_blocker to NULL marks the "done"
@@ -841,9 +841,9 @@ locks_delete_lock_ctx(struct file_lock *fl, struct list_head *dispose)
 static bool locks_conflict(struct file_lock *caller_fl,
                           struct file_lock *sys_fl)
 {
-       if (sys_fl->fl_type == F_WRLCK)
+       if (lock_is_write(sys_fl))
                return true;
-       if (caller_fl->fl_type == F_WRLCK)
+       if (lock_is_write(caller_fl))
                return true;
        return false;
 }
@@ -874,7 +874,7 @@ static bool posix_test_locks_conflict(struct file_lock *caller_fl,
                                      struct file_lock *sys_fl)
 {
        /* F_UNLCK checks any locks on the same fd. */
-       if (caller_fl->fl_type == F_UNLCK) {
+       if (lock_is_unlock(caller_fl)) {
                if (!posix_same_owner(caller_fl, sys_fl))
                        return false;
                return locks_overlap(caller_fl, sys_fl);
@@ -1055,7 +1055,7 @@ static int flock_lock_inode(struct inode *inode, struct file_lock *request)
                break;
        }
 
-       if (request->fl_type == F_UNLCK) {
+       if (lock_is_unlock(request)) {
                if ((request->fl_flags & FL_EXISTS) && !found)
                        error = -ENOENT;
                goto out;
@@ -1107,7 +1107,7 @@ static int posix_lock_inode(struct inode *inode, struct file_lock *request,
 
        ctx = locks_get_lock_context(inode, request->fl_type);
        if (!ctx)
-               return (request->fl_type == F_UNLCK) ? 0 : -ENOMEM;
+               return lock_is_unlock(request) ? 0 : -ENOMEM;
 
        /*
         * We may need two file_lock structures for this operation,
@@ -1228,7 +1228,7 @@ retry:
                                continue;
                        if (fl->fl_start > request->fl_end)
                                break;
-                       if (request->fl_type == F_UNLCK)
+                       if (lock_is_unlock(request))
                                added = true;
                        if (fl->fl_start < request->fl_start)
                                left = fl;
@@ -1279,7 +1279,7 @@ retry:
 
        error = 0;
        if (!added) {
-               if (request->fl_type == F_UNLCK) {
+               if (lock_is_unlock(request)) {
                        if (request->fl_flags & FL_EXISTS)
                                error = -ENOENT;
                        goto out;
@@ -1608,7 +1608,7 @@ void lease_get_mtime(struct inode *inode, struct timespec64 *time)
                spin_lock(&ctx->flc_lock);
                fl = list_first_entry_or_null(&ctx->flc_lease,
                                              struct file_lock, fl_list);
-               if (fl && (fl->fl_type == F_WRLCK))
+               if (fl && lock_is_write(fl))
                        has_lease = true;
                spin_unlock(&ctx->flc_lock);
        }

diff --git a/include/linux/filelock.h b/include/linux/filelock.h
index 085ff6ba06536d39ff0489bb9d548d93759abe03..a3cb59b7922a298529a1d7fb8d5add8751bd8058 100644 (file)
--- a/include/linux/filelock.h
+++ b/include/linux/filelock.h
@@ -147,6 +147,29 @@ int fcntl_setlk64(unsigned int, struct file *, unsigned int,
 int fcntl_setlease(unsigned int fd, struct file *filp, int arg);
 int fcntl_getlease(struct file *filp);
 
+static inline bool lock_is_unlock(struct file_lock *fl)
+{
+       return fl->fl_type == F_UNLCK;
+}
+
+static inline bool lock_is_read(struct file_lock *fl)
+{
+       return fl->fl_type == F_RDLCK;
+}
+
+static inline bool lock_is_write(struct file_lock *fl)
+{
+       return fl->fl_type == F_WRLCK;
+}
+
+static inline void locks_wake_up(struct file_lock *fl)
+{
+       wake_up(&fl->fl_wait);
+}
+
+/* for walking lists of file_locks linked by fl_list */
+#define for_each_file_lock(_fl, _head) list_for_each_entry(_fl, _head, fl_list)
+
 /* fs/locks.c */
 void locks_free_lock_context(struct inode *inode);
 void locks_free_lock(struct file_lock *fl);
@@ -223,6 +246,27 @@ static inline int fcntl_getlease(struct file *filp)
        return F_UNLCK;
 }
 
+static inline bool lock_is_unlock(struct file_lock *fl)
+{
+       return false;
+}
+
+static inline bool lock_is_read(struct file_lock *fl)
+{
+       return false;
+}
+
+static inline bool lock_is_write(struct file_lock *fl)
+{
+       return false;
+}
+
+static inline void locks_wake_up(struct file_lock *fl)
+{
+}
+
+#define for_each_file_lock(_fl, _head) while(false)
+
 static inline void
 locks_free_lock_context(struct inode *inode)
 {