io_uring/fdinfo: fix io_uring_show_fdinfo() misuse of ->d_iname

Output of io_uring_show_fdinfo() has several problems:

* racy use of ->d_iname
* junk if the name is long - in that case it's not stored in ->d_iname
at all
* lack of quoting (names can contain newlines, etc. - or be equal to "<none>",
for that matter).
* lines for empty slots are pointless noise - we already have the total
amount, so having just the non-empty ones would carry the same information.

Signed-off-by: Al Viro <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>

diff --git a/io_uring/fdinfo.c b/io_uring/fdinfo.c
index b214e5a407b565d32532f7c3bf8917034a1fe8aa..f60d0a9d505e25be99bca479efcf554003f9d625 100644 (file)
--- a/io_uring/fdinfo.c
+++ b/io_uring/fdinfo.c
@@ -211,10 +211,11 @@ __cold void io_uring_show_fdinfo(struct seq_file *m, struct file *file)
 
                if (ctx->file_table.data.nodes[i])
                        f = io_slot_file(ctx->file_table.data.nodes[i]);
-               if (f)
-                       seq_printf(m, "%5u: %s\n", i, file_dentry(f)->d_iname);
-               else
-                       seq_printf(m, "%5u: <none>\n", i);
+               if (f) {
+                       seq_printf(m, "%5u: ", i);
+                       seq_file_path(m, f, " \t\n\\");
+                       seq_puts(m, "\n");
+               }
        }
        seq_printf(m, "UserBufs:\t%u\n", ctx->buf_table.nr);
        for (i = 0; has_lock && i < ctx->buf_table.nr; i++) {