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Sun, 19 Jan 2025 03:26:49 +0000
Date: Sun, 19 Jan 2025 03:26:49 +0000
From: Al Viro <viro@zeniv.linux.org.uk>
To: Jens Axboe <axboe@kernel.dk>
Cc: linux-fsdevel@vger.kernel.org, Pavel Begunkov <asml.silence@gmail.com>,
io-uring@vger.kernel.org,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [RFC][PATCH] fix io_uring_show_fdinfo() misuse of ->d_iname
Message-ID: <20250119032649.GW1977892@ZenIV>
References: <20250118025717.GU1977892@ZenIV>
<cf13b64b-29fb-47b9-ae2d-1dcedd8cc415@kernel.dk>
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Sender: Al Viro <viro@ftp.linux.org.uk>
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 <viro@zeniv.linux.org.uk>
---
diff --git a/io_uring/fdinfo.c b/io_uring/fdinfo.c
index b214e5a407b5..f60d0a9d505e 100644
--- 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++) {