Make fcntl locks work on unseekable files too

Fixes #2267
ish-app · Oct 20, 2024 · f1ea54d · f1ea54d · jaclu · Oct 20, 2024
1 parent c993ea7
commit f1ea54d
Showing 1 changed file with 9 additions and 5 deletions.
diff --git a/fs/lock.c b/fs/lock.c
@@ -144,11 +144,15 @@ static int file_lock_from_flock(struct fd *fd, struct flock_ *flock, struct file
             offset = 0;
             break;
         case LSEEK_CUR:
-            lock(&fd->lock);
-            offset = fd->ops->lseek(fd, 0, LSEEK_CUR);
-            unlock(&fd->lock);
-            if (offset < 0)
-                return offset;
+            if (!fd->ops->lseek) {
+                offset = 0;
+            } else {
+                lock(&fd->lock);
+                offset = fd->ops->lseek(fd, 0, LSEEK_CUR);
+                unlock(&fd->lock);
+                if (offset < 0)
+                    return offset;
+            }
             break;
         case LSEEK_END: {
             struct statbuf stat;