fs/inode: add common function to get file count from list

common function to get file count from file list

Signed-off-by: chao an <anchao@xiaomi.com>

fs/inode/fs_files.c

@@ -98,7 +98,7 @@ static int files_extend(FAR struct filelist *list, size_t row)
       return 0;
     }
 
-  if (row * CONFIG_NFILE_DESCRIPTORS_PER_BLOCK > OPEN_MAX)
+  if (files_countlist(list) > OPEN_MAX)
     {
       return -EMFILE;
     }
@@ -214,6 +214,7 @@ static int nx_dup3_from_tcb(FAR struct tcb_s *tcb, int fd1, int fd2,
   FAR struct filelist *list;
   FAR struct file *filep;
   FAR struct file  file;
+  int count;
   int ret;
 
   if (fd1 == fd2)
@@ -228,15 +229,17 @@ static int nx_dup3_from_tcb(FAR struct tcb_s *tcb, int fd1, int fd2,
 
   list = nxsched_get_files_from_tcb(tcb);
 
+  count = files_countlist(list);
+
   /* Get the file descriptor list.  It should not be NULL in this context. */
 
-  if (fd1 < 0 || fd1 >= CONFIG_NFILE_DESCRIPTORS_PER_BLOCK * list->fl_rows ||
+  if (fd1 < 0 || fd1 >= count ||
       fd2 < 0)
     {
       return -EBADF;
     }
 
-  if (fd2 >= CONFIG_NFILE_DESCRIPTORS_PER_BLOCK * list->fl_rows)
+  if (fd2 >= count)
     {
       ret = files_extend(list, fd2 / CONFIG_NFILE_DESCRIPTORS_PER_BLOCK + 1);
       if (ret < 0)
@@ -315,6 +318,28 @@ void files_releaselist(FAR struct filelist *list)
   kmm_free(list->fl_files);
 }
 
+/****************************************************************************
+ * Name: files_countlist
+ *
+ * Description:
+ *   Given a file descriptor, return the corresponding instance of struct
+ *   file.
+ *
+ * Input Parameters:
+ *   fd    - The file descriptor
+ *   filep - The location to return the struct file instance
+ *
+ * Returned Value:
+ *   Zero (OK) is returned on success; a negated errno value is returned on
+ *   any failure.
+ *
+ ****************************************************************************/
+
+int files_countlist(FAR struct filelist *list)
+{
+  return list->fl_rows * CONFIG_NFILE_DESCRIPTORS_PER_BLOCK;
+}
+
 /****************************************************************************
  * Name: file_allocate_from_tcb
  *
@@ -562,7 +587,7 @@ int fs_getfilep(int fd, FAR struct file **filep)
       return -EAGAIN;
     }
 
-  if (fd < 0 || fd >= list->fl_rows * CONFIG_NFILE_DESCRIPTORS_PER_BLOCK)
+  if (fd < 0 || fd >= files_countlist(list))
     {
       return -EBADF;
     }
@@ -714,7 +739,7 @@ int nx_close_from_tcb(FAR struct tcb_s *tcb, int fd)
 
   /* Perform the protected close operation */
 
-  if (fd < 0 || fd >= list->fl_rows * CONFIG_NFILE_DESCRIPTORS_PER_BLOCK)
+  if (fd < 0 || fd >= files_countlist(list))
     {
       return -EBADF;
     }

fs/procfs/fs_procfsproc.c

@@ -1188,17 +1188,24 @@ static ssize_t proc_groupfd(FAR struct proc_file_s *procfile,
                             size_t buflen, off_t offset)
 {
   FAR struct task_group_s *group = tcb->group;
-  FAR struct file *file;
+  FAR struct file *filep;
   char path[PATH_MAX];
   size_t remaining;
   size_t linesize;
   size_t copysize;
   size_t totalsize;
+  int count;
+  int ret;
   int i;
-  int j;
 
   DEBUGASSERT(group != NULL);
 
+  count = files_countlist(&group->tg_filelist);
+  if (count == 0)
+    {
+      return 0;
+    }
+
   remaining = buflen;
   totalsize = 0;
 
@@ -1219,41 +1226,34 @@ static ssize_t proc_groupfd(FAR struct proc_file_s *procfile,
 
   /* Examine each open file descriptor */
 
-  for (i = 0; i < group->tg_filelist.fl_rows; i++)
+  for (i = 0; i < count; i++)
     {
-      for (j = 0, file = group->tg_filelist.fl_files[i];
-           j < CONFIG_NFILE_DESCRIPTORS_PER_BLOCK;
-           j++, file++)
+      ret = fs_getfilep(i, &filep);
+      if (ret != OK || filep == NULL)
         {
-          /* Is there an inode associated with the file descriptor? */
+          continue;
+        }
 
-          if (file->f_inode == NULL)
-            {
-              continue;
-            }
+      if (file_ioctl(filep, FIOC_FILEPATH, path) < 0)
+        {
+          path[0] = '\0';
+        }
 
-          if (file_ioctl(file, FIOC_FILEPATH, path) < 0)
-            {
-              path[0] = '\0';
-            }
+      linesize   = procfs_snprintf(procfile->line, STATUS_LINELEN,
+                                   "%-3d %-7d %-4x %-9ld %s\n",
+                                   i, filep->f_oflags,
+                                   INODE_GET_TYPE(filep->f_inode),
+                                   (long)filep->f_pos, path);
+      copysize   = procfs_memcpy(procfile->line, linesize,
+                                 buffer, remaining, &offset);
 
-          linesize   = procfs_snprintf(procfile->line, STATUS_LINELEN,
-                                       "%-3d %-7d %-4x %-9ld %s\n",
-                                       i * CONFIG_NFILE_DESCRIPTORS_PER_BLOCK
-                                       + j, file->f_oflags,
-                                       INODE_GET_TYPE(file->f_inode),
-                                       (long)file->f_pos, path);
-          copysize   = procfs_memcpy(procfile->line, linesize,
-                                     buffer, remaining, &offset);
+      totalsize += copysize;
+      buffer    += copysize;
+      remaining -= copysize;
 
-          totalsize += copysize;
-          buffer    += copysize;
-          remaining -= copysize;
-
-          if (totalsize >= buflen)
-            {
-              return totalsize;
-            }
+      if (totalsize >= buflen)
+        {
+          return totalsize;
         }
     }
 

include/nuttx/fs/fs.h

@@ -852,6 +852,19 @@ void files_initlist(FAR struct filelist *list);
 
 void files_releaselist(FAR struct filelist *list);
 
+/****************************************************************************
+ * Name: files_countlist
+ *
+ * Description:
+ *   Get file count from file list
+ *
+ * Returned Value:
+ *   file count of file list
+ *
+ ****************************************************************************/
+
+int files_countlist(FAR struct filelist *list);
+
 /****************************************************************************
  * Name: files_duplist
  *