[incubator-nuttx] 03/04: rpmsgfs: cache statfs result in case of deadlock

[pk...@apache.org]

This is an automated email from the ASF dual-hosted git repository.

pkarashchenko pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/incubator-nuttx.git

commit 572d8650340550a467d4583eb7d5c2b184eb7475
Author: ligd <li...@xiaomi.com>
AuthorDate: Thu Jul 7 14:43:59 2022 +0800

    rpmsgfs: cache statfs result in case of deadlock
    
    rptun: msg from other cpu
    [ap] [ 5] [<0x2c353768>] arm_switchcontext+0xc/0x10
    [ap] [ 5] [<0x2c322266>] sem_wait+0x5a/0xbc
    [ap] [ 5] [<0x2c7400a8>] inode_semtake+0x24/0x5c
    [ap] [ 5] [<0x2c74087a>] inode_release+0x6/0x60
    [ap] [ 5] [<0x2c741284>] file_close+0x18/0x44
    [ap] [ 5] [<0x2c74fb06>] rpmsgfs_close_handler+0x86/0xe4
    [ap] [ 5] [<0x2c75b8de>] rpmsg_virtio_rx_callback+0xba/0x1b4
    [ap] [ 5] [<0x2c75af70>] rproc_virtio_notified+0x44/0x5c
    [ap] [ 5] [<0x2c75a93c>] remoteproc_get_notification+0x1c/0x2c
    [ap] [ 5] [<0x2c335a08>] rptun_thread+0x74/0x208
    [ap] [ 5] [<0x2c323e72>] nxtask_start+0x3a/0x60
    
    nsh: send msg to other cpu with inode lock
    [ap] [10] [<0x2c353768>] arm_switchcontext+0xc/0x10
    [ap] [10] [<0x2c3221b2>] nxsem_wait_uninterruptible+0x6e/0xc8
    [ap] [10] [<0x2c74e498>] rpmsgfs_send_recv.constprop.0+0x78/0xc0
    [ap] [10] [<0x2c74ebc0>] rpmsgfs_client_statfs+0x50/0x80
    [ap] [10] [<0x2c3221ca>] nxsem_wait_uninterruptible+0x86/0xc8
    [ap] [10] [<0x2c74da78>] rpmsgfs_statfs+0x28/0x50
    [ap] [10] [<0x2c74534e>] mountpoint_filter+0x66/0x90
    [ap] [10] [<0x2c740016>] foreach_inodelevel+0x66/0x88
    [ap] [10] [<0x2c73fffa>] foreach_inodelevel+0x4a/0x88
    [ap] [10] [<0x2c740062>] foreach_inode+0x2a/0x48
    [ap] [10] [<0x2c745388>] foreach_mountpoint+0x10/0x20
    [ap] [10] [<0x2c745606>] mount_read+0x36/0x70
    [ap] [10] [<0x2c742a34>] read+0x30/0x5c
    [ap] [10] [<0x2c371096>] nsh_catfile+0x36/0x140
    [ap] [10] [<0x2c36d01a>] nsh_parse_command+0x7fe/0xc54
    [ap] [10] [<0x2c370f92>] nsh_session+0x66/0x134
    [ap] [10] [<0x2c3721a4>] nsh_consolemain+0x2c/0x44
    [ap] [10] [<0x2c374fde>] nsh_main+0x2a/0x4c
    [ap] [10] [<0x2c33f7f8>] lib_cxx_initialize+0x24/0x48
    [ap] [10] [<0x2c34274a>] nxtask_startup+0x12/0x24
    [ap] [10] [<0x2c323e7e>] nxtask_start+0x46/0x60
    
    Signed-off-by: ligd <li...@xiaomi.com>
---
 fs/rpmsgfs/rpmsgfs.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/fs/rpmsgfs/rpmsgfs.c b/fs/rpmsgfs/rpmsgfs.c
index 36ef3fd90a..e225d8e79d 100644
--- a/fs/rpmsgfs/rpmsgfs.c
+++ b/fs/rpmsgfs/rpmsgfs.c
@@ -78,6 +78,7 @@ struct rpmsgfs_mountpt_s
   char                       fs_root[PATH_MAX];
   void                       *handle;
   int                        timeout;  /* Connect timeout */
+  struct statfs              statfs;
 };
 
 /****************************************************************************
@@ -1232,12 +1233,21 @@ static int rpmsgfs_statfs(FAR struct inode *mountpt, FAR struct statfs *buf)
       return ret;
     }
 
+  if (fs->statfs.f_type == RPMSGFS_MAGIC)
+    {
+      memcpy(buf, &fs->statfs, sizeof(struct statfs));
+      rpmsgfs_semgive(fs);
+      return 0;
+    }
+
   /* Call the host fs to perform the statfs */
 
   memset(buf, 0, sizeof(struct statfs));
   ret = rpmsgfs_client_statfs(fs->handle, fs->fs_root, buf);
   buf->f_type = RPMSGFS_MAGIC;
 
+  memcpy(&fs->statfs, buf, sizeof(struct statfs));
+
   rpmsgfs_semgive(fs);
   return ret;
 }