linux-kernel - Re: [PATCH] Fuse: Add backing file support for uring

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <e0019be0-1167-4024-8268-e320fee4bc50@gmail.com>
Date: Fri, 21 Feb 2025 09:36:30 -0600
From: Moinak Bhattacharyya <moinakb001@...il.com>
To: Bernd Schubert <bernd@...ernd.com>, Miklos Szeredi <miklos@...redi.hu>,
 linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
 io-uring@...r.kernel.org, Amir Goldstein <amir73il@...il.com>
Subject: Re: [PATCH] Fuse: Add backing file support for uring_cmd

Sorry about that. Correctly-formatted patch follows. Should I send out a 
V2 instead?

Add support for opening and closing backing files in the fuse_uring_cmd 
callback. Store backing_map (for open) and backing_id (for close) in the 
uring_cmd data.
---
  fs/fuse/dev_uring.c       | 50 +++++++++++++++++++++++++++++++++++++++
  include/uapi/linux/fuse.h |  6 +++++
  2 files changed, 56 insertions(+)

diff --git a/fs/fuse/dev_uring.c b/fs/fuse/dev_uring.c
index ebd2931b4f2a..df73d9d7e686 100644
--- a/fs/fuse/dev_uring.c
+++ b/fs/fuse/dev_uring.c
@@ -1033,6 +1033,40 @@ fuse_uring_create_ring_ent(struct io_uring_cmd *cmd,
      return ent;
  }

+/*
+ * Register new backing file for passthrough, getting backing map from 
URING_CMD data
+ */
+static int fuse_uring_backing_open(struct io_uring_cmd *cmd,
+    unsigned int issue_flags, struct fuse_conn *fc)
+{
+    const struct fuse_backing_map *map = io_uring_sqe_cmd(cmd->sqe);
+    int ret = fuse_backing_open(fc, map);
+
+    if (ret < 0) {
+        return ret;
+    }
+
+    io_uring_cmd_done(cmd, ret, 0, issue_flags);
+    return 0;
+}
+
+/*
+ * Remove file from passthrough tracking, getting backing_id from 
URING_CMD data
+ */
+static int fuse_uring_backing_close(struct io_uring_cmd *cmd,
+    unsigned int issue_flags, struct fuse_conn *fc)
+{
+    const int *backing_id = io_uring_sqe_cmd(cmd->sqe);
+    int ret = fuse_backing_close(fc, *backing_id);
+
+    if (ret < 0) {
+        return ret;
+    }
+
+    io_uring_cmd_done(cmd, ret, 0, issue_flags);
+    return 0;
+}
+
  /*
   * Register header and payload buffer with the kernel and puts the
   * entry as "ready to get fuse requests" on the queue
@@ -1144,6 +1178,22 @@ int fuse_uring_cmd(struct io_uring_cmd *cmd, 
unsigned int issue_flags)
              return err;
          }
          break;
+    case FUSE_IO_URING_CMD_BACKING_OPEN:
+        err = fuse_uring_backing_open(cmd, issue_flags, fc);
+        if (err) {
+            pr_info_once("FUSE_IO_URING_CMD_BACKING_OPEN failed err=%d\n",
+                    err);
+            return err;
+        }
+        break;
+    case FUSE_IO_URING_CMD_BACKING_CLOSE:
+        err = fuse_uring_backing_close(cmd, issue_flags, fc);
+        if (err) {
+            pr_info_once("FUSE_IO_URING_CMD_BACKING_CLOSE failed err=%d\n",
+                    err);
+            return err;
+        }
+        break;
      default:
          return -EINVAL;
      }
diff --git a/include/uapi/linux/fuse.h b/include/uapi/linux/fuse.h
index 5e0eb41d967e..634265da1328 100644
--- a/include/uapi/linux/fuse.h
+++ b/include/uapi/linux/fuse.h
@@ -1264,6 +1264,12 @@ enum fuse_uring_cmd {

      /* commit fuse request result and fetch next request */
      FUSE_IO_URING_CMD_COMMIT_AND_FETCH = 2,
+
+    /* add new backing file for passthrough */
+    FUSE_IO_URING_CMD_BACKING_OPEN = 3,
+
+    /* remove passthrough file by backing_id */
+    FUSE_IO_URING_CMD_BACKING_CLOSE = 4,
  };

  /**
-- 
2.39.5 (Apple Git-154)