From 01bed328effaa38391892c7d50eb3a0218948374 Mon Sep 17 00:00:00 2001
From: Michal Lenc <michallenc@seznam.cz>
Date: Mon, 23 Sep 2024 21:57:18 +0200
Subject: [PATCH] smartfs: add support for FIOC_FILEPATH ioctl

The FIOC_FILEPATH ioctl call is required if smartfs is to be used
together with inotify monitoring system. This implements the
call support to smartfs file system. The path to the file has to
be stored in smartfs_ofile_s structure during file open (and is freed
during close) as smartfs currently is not able to obtain the path
knowing only the file node. The full path is concatenated with the file
name and creates the full path needed for inotify to detect whether
the file is on the watchlist.

Signed-off-by: Michal Lenc <michallenc@seznam.cz>
---
 fs/smartfs/smartfs.h       |  1 +
 fs/smartfs/smartfs_smart.c | 45 +++++++++++++++++++++++++++++++++++---
 2 files changed, 43 insertions(+), 3 deletions(-)

diff --git a/fs/smartfs/smartfs.h b/fs/smartfs/smartfs.h
index f7d6d42acd..4e0ac9a152 100644
--- a/fs/smartfs/smartfs.h
+++ b/fs/smartfs/smartfs.h
@@ -307,6 +307,7 @@ struct smartfs_ofile_s
                                              * a seek, or more data is written that
                                              * causes the sector to change.
                                              */
+  char                        path[1];      /* The full path to the file */
 };
 
 /* This structure represents the overall mountpoint state.  An instance of
diff --git a/fs/smartfs/smartfs_smart.c b/fs/smartfs/smartfs_smart.c
index c0e92c7b66..3533a24894 100644
--- a/fs/smartfs/smartfs_smart.c
+++ b/fs/smartfs/smartfs_smart.c
@@ -44,6 +44,7 @@
 #include <nuttx/mtd/mtd.h>
 #include <nuttx/fs/smart.h>
 
+#include "inode/inode.h"
 #include "smartfs.h"
 
 /****************************************************************************
@@ -181,6 +182,7 @@ static int smartfs_open(FAR struct file *filep, FAR const char *relpath,
   FAR struct smartfs_mountpt_s *fs;
   int                           ret;
   uint16_t                      parentdirsector;
+  size_t                        pathlen;
   FAR const char               *filename;
   FAR struct smartfs_ofile_s   *sf;
 #ifdef CONFIG_SMARTFS_USE_SECTOR_BUFFER
@@ -210,13 +212,20 @@ static int smartfs_open(FAR struct file *filep, FAR const char *relpath,
 
   /* Locate the directory entry for this path */
 
-  sf = kmm_malloc(sizeof *sf);
+  pathlen = strlen(relpath) + 1;
+  sf = kmm_malloc(sizeof(*sf) + pathlen - 1);
   if (sf == NULL)
     {
       ret = -ENOMEM;
       goto errout_with_lock;
     }
 
+  /* Save the full path to smartfs_ofile_s stuctrue. This is needed
+   * to FIOC_FILEPATH ioctlc all support.
+   */
+
+  memcpy(sf->path, relpath, pathlen);
+
   /* Allocate a sector buffer if CRC enabled in the MTD layer */
 
 #ifdef CONFIG_SMARTFS_USE_SECTOR_BUFFER
@@ -997,9 +1006,39 @@ static off_t smartfs_seek(FAR struct file *filep, off_t offset, int whence)
 
 static int smartfs_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
 {
-  /* We don't use any ioctls */
+  FAR struct smartfs_ofile_s *priv;
+  FAR struct inode *inode;
+  int ret;
 
-  return -ENOSYS;
+  /* Recover our private data from the struct file instance */
+
+  priv  = filep->f_priv;
+  inode = filep->f_inode;
+
+  switch (cmd)
+    {
+      case FIOC_FILEPATH:
+        {
+          FAR char *path = (FAR char *)(uintptr_t)arg;
+          ret = inode_getpath(inode, path, PATH_MAX);
+          if (ret >= 0)
+            {
+              size_t len = strlen(path);
+              if (path[len - 1] != '/')
+                {
+                  path[len++] = '/';
+                }
+
+              strlcat(path, priv->path, PATH_MAX - len);
+            }
+        }
+        break;
+      default:
+        ret = -ENOSYS;
+        break;
+    }
+
+  return ret;
 }
 
 /****************************************************************************