1 files changed, 521 insertions, 0 deletions
diff --git a/nuttx/fs/nxffs/nxffs_open.c b/nuttx/fs/nxffs/nxffs_open.c
new file mode 100644
index 000000000..a7caebca5
--- /dev/null
+++ b/nuttx/fs/nxffs/nxffs_open.c
@@ -0,0 +1,521 @@
+/****************************************************************************
+ * fs/nxffs/nxffs_open.c
+ *
+ *   Copyright (C) 2011 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * References: Linux/Documentation/filesystems/romfs.txt
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <string.h>
+#include <fcntl.h>
+#include <assert.h>
+#include <errno.h>
+#include <debug.h>
+
+#include <nuttx/kmalloc.h>
+#include <nuttx/fs.h>
+#include <nuttx/mtd.h>
+
+#include "nxffs.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Variables
+ ****************************************************************************/
+
+/* A singly-linked list of open files */
+
+static struct nxffs_ofile_s *g_ofiles;
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: nxffs_create
+ *
+ * Description:
+ *   Create a file:  Verify the sufficient space exists at the end of the
+ *   FLASH.  If so, then write then update entry in preparation for writing.
+ *
+ ****************************************************************************/
+
+static inline int nxffs_create(FAR struct nxffs_volume_s *volume,
+                               FAR const char *name, mode_t mode,
+                               FAR struct nxffs_ofile_s **ppofile)
+{
+#warning "Check if too close to end of block for whole header"
+  return OK;
+}
+
+/****************************************************************************
+ * Name: nxffs_wropen
+ *
+ * Description:
+ *   Handle opening for writing.  Only a single writer is permitted and only
+ *   file creation is supported.
+ *
+ ****************************************************************************/
+
+static inline int nxffs_wropen(FAR struct nxffs_volume_s *volume,
+                               FAR const char *name, mode_t mode,
+                               FAR struct nxffs_ofile_s **ppofile)
+{
+  FAR struct nxffs_wrfile_s *wrfile;
+  FAR struct nxffs_entry_s entry;
+  int ret;
+
+  /* Limitation: Only a single writer is permitted.  Writing may involve
+   * extension of the file system in FLASH.  Since files are contiguous
+   * in FLASH, only a single file may be extending the FLASH region.
+   */
+
+  if (volume->wrbusy)
+    {
+      fdbg("There is already a file writer\n");
+      return -ENOSYS;
+    }
+
+  /* Check if the file exists */
+
+  ret = nxffs_findinode(volume, name, &entry);
+  if (ret == OK)
+    {
+      /* It exists.  It would be an error if we are asked to create it
+       * exclusively.
+       */
+
+      if ((mode & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL))
+        {
+          fdbg("File exists, can't create O_EXCL\n");
+          return -EEXIST;
+        }
+
+      /* Were we asked to truncate the file?  NOTE: Don't truncate the
+       * file if we were not also asked to created it.  See below...
+       * we will not re-create the file unless O_CREAT is also specified.
+       */
+
+      else if ((mode & (O_CREAT|O_TRUNC)) == (O_CREAT|O_TRUNC))
+        {
+          /* Just remove the file and fall through to re-create it */
+#warning "Should defer file removal until new file successfully written"
+
+          ret = nxffs_rminode(volume, name);
+          if (ret < 0)
+            {
+              fdbg("nxffs_rminode failed: %d\n", -ret);
+              return ret;
+            }
+        }
+
+      /* The file exists and we were not asked to truncate (and recreate) it.
+       * Limitation: Cannot write to existing files.
+       */
+
+      else
+        {
+          fdbg("File %s exists and we were not asked to truncate it\n");
+          return -ENOSYS;
+        }
+    }
+
+  /* Okay, the file is not open and does not exists (maybe because we deleted
+   * it).  Now, make sure that we were asked to created it.
+   */
+
+  if ((mode & O_CREAT) == 0)
+    {
+      fdbg("Not asked to create the file\n");
+      return -ENOENT;
+    }
+
+  /* Yes.. Create a new structure that will describe the state of this open
+   * file.  NOTE that a special variant of the open file structure is used
+   * that includes additional information to support the write operation.
+   */
+
+  wrfile = (FAR struct nxffs_wrfile_s *)kzalloc(sizeof(struct nxffs_wrfile_s));
+  if (!wrfile)
+    {
+      return -ENOMEM;
+    }
+
+  /* Initialize the open file state structure */
+
+  wrfile->ofile.crefs  = 1;
+
+  /* Allocate FLASH memory for the file and set up for the write */
+
+#warning "Missing Logic"
+
+  /* Add the open file structure to the head of the list of open files */
+
+  wrfile->ofile.flink = g_ofiles;
+  g_ofiles            = &wrfile->ofile;
+
+  /* Indicate that the volume is open for writing and return the open file
+   * instance.
+   */
+
+  volume->wrbusy = 1;
+  *ppofile = &wrfile->ofile;
+  return OK;
+}
+
+/****************************************************************************
+ * Name: nxffs_rdopen
+ *
+ * Description:
+ *   Open an existing file for reading.
+ *
+ ****************************************************************************/
+
+static inline int nxffs_rdopen(FAR struct nxffs_volume_s *volume,
+                               FAR const char *name,
+                               FAR struct nxffs_ofile_s **ppofile)
+{
+  FAR struct nxffs_ofile_s *ofile;
+  int ret;
+
+  /* Check if the file has already been opened (for reading) */
+
+  ofile = nxffs_findofile(name);
+  if (ofile)
+    {
+      /* The file is already open.
+       * Limitation:  Files cannot be open both for reading and writing.
+       */
+
+      if ((ofile->mode & O_WROK) != 0)
+        {
+          fdbg("File is open for writing\n");
+          return -ENOSYS;
+        }
+
+      /* Just increment the reference count on the ofile */
+
+      ofile->crefs++;
+      fdbg("crefs: %d\n", ofile->crefs);
+    }
+
+  /* The file has not yet been opened.
+   * Limitation: The file must exist.  We do not support creation of files
+   * read-only.
+   */
+
+  else
+    {
+      /* Not already open.. create a new open structure */
+ 
+      ofile = (FAR struct nxffs_ofile_s *)kzalloc(sizeof(struct nxffs_ofile_s));
+      if (!ofile)
+        {
+          fdbg("ofile allocation failed\n");
+          return -ENOMEM;
+        }
+
+      /* Initialize the open file state structure */
+
+      ofile->crefs  = 1;
+
+      /* Find the file on this volume associated with this file name */
+
+      ret = nxffs_findinode(volume, name, &ofile->entry);
+      if (ret != OK)
+        {
+          fdbg("Inode '%s' not found: %d\n", name, -ret);
+          kfree(ofile);
+          return ret;
+        }
+
+      /* Add the open file structure to the head of the list of open files */
+
+      ofile->flink = g_ofiles;
+      g_ofiles     = ofile;
+    }
+
+  /* Return the open file state structure */
+
+  *ppofile = ofile;
+  return OK;
+}
+
+/****************************************************************************
+ * Name: nxffs_freeofile
+ ****************************************************************************/
+
+static inline void nxffs_freeofile(FAR struct nxffs_ofile_s *ofile)
+{
+  FAR struct nxffs_ofile_s *prev;
+  FAR struct nxffs_ofile_s *curr;
+
+  /* Find the open file structure to be removed */
+
+  for (prev = NULL, curr = g_ofiles;
+       curr && curr != ofile;
+       prev = curr, curr = curr->flink);
+
+  /* Was it found? */
+
+  if (curr)
+    {
+      /* Yes.. at the head of the list? */
+
+      if (prev)
+        {
+          prev->flink = ofile->flink;
+        }
+      else
+        {
+          g_ofiles = ofile->flink;
+        }
+
+      /* Then free the open file */
+
+      nxffs_freeentry(&ofile->entry);
+      kfree(ofile);
+    }
+  else
+    {
+      fdbg("ERROR: Open inode %p not found\n", ofile);
+    }
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: nxffs_findofile
+ *
+ * Description:
+ *   Search the list of already opened files to see if the inode of this
+ *   name is one of the opened files.
+ *
+ * Input Parameters:
+ *   name - The name of the inode to check.
+ *
+ * Returned Value:
+ *   If an inode of this name is found in the list of opened inodes, then
+ *   a reference to the open file structure is returned.  NULL is returned
+ *   otherwise.
+ *
+ ****************************************************************************/
+
+FAR struct nxffs_ofile_s *nxffs_findofile(FAR const char *name)
+{
+  FAR struct nxffs_ofile_s *ofile;
+
+  /* Check every open file.  Note that the volume exclsem protects the
+   * list of open files.
+   */
+
+  for (ofile = g_ofiles; ofile; ofile = ofile->flink)
+    {
+      /* Check for a name match */
+
+      if (strcmp(name, ofile->entry.name) == 0)
+        {
+          return ofile;
+        }
+    }
+
+  return NULL;
+}
+
+/****************************************************************************
+ * Name: nxffs_open
+ *
+ * Description:
+ *   This is the standard mountpoint open method.
+ *
+ ****************************************************************************/
+
+int nxffs_open(FAR struct file *filep, FAR const char *relpath,
+               int oflags, mode_t mode)
+{
+  FAR struct nxffs_volume_s *volume;
+  FAR struct nxffs_ofile_s *ofile = NULL;
+  int ret;
+
+  fvdbg("Open '%s'\n", relpath);
+
+  /* Sanity checks */
+
+  DEBUGASSERT(filep->f_priv == NULL && filep->f_inode != NULL);
+
+  /* Get the mountpoint private data from the NuttX inode reference in the
+   * file structure
+   */
+
+  volume = (FAR struct nxffs_volume_s*)filep->f_inode->i_private;
+  DEBUGASSERT(volume != NULL);
+
+  /* Get exclusive access to the volume.  Note that the volume exclsem
+   * protects the open file list.
+   */
+
+  ret = sem_wait(&volume->exclsem);
+  if (ret != OK)
+    {
+      ret = -errno;
+      fdbg("sem_wait failed: %d\n", ret);
+      goto errout;
+    }
+
+#ifdef CONFIG_FILE_MODE
+#  warning "Missing check for privileges based on inode->i_mode"
+#endif
+
+  /* Limitation:  A file must be opened for reading or writing, but not both.
+   * There is no general for extending the size of of a file.  Extending the
+   * file size of possible if the file to be extended is the last in the
+   * sequence on FLASH, but since that case is not the general case, no file
+   * extension is supported.
+   */
+
+   switch (mode & (O_WROK|O_RDOK))
+     {
+       case 0:
+       default:
+         fdbg("One of O_WRONLY/O_RDONLY must be provided\n");
+         ret = -EINVAL;
+         goto errout_with_semaphore;
+
+       case O_WROK:
+         ret = nxffs_wropen(volume, relpath, mode, &ofile);
+         break;
+
+       case O_RDOK:
+         ret = nxffs_rdopen(volume, relpath, &ofile);
+         break;
+
+       case O_WROK|O_RDOK:
+         fdbg("O_RDWR is not supported\n");
+         ret = -ENOSYS;
+         goto errout_with_semaphore;
+     }
+
+  /* Save open-specific state in filep->f_priv */
+
+  filep->f_priv = ofile;
+  ret = OK;
+
+errout_with_semaphore:
+  sem_post(&volume->exclsem);
+errout:
+  return ret;
+}
+
+/****************************************************************************
+ * Name: nxffs_close
+ *
+ * Description:
+ *   This is the standard mountpoint close method.
+ *
+ ****************************************************************************/
+
+int nxffs_close(FAR struct file *filep)
+{
+  FAR struct nxffs_volume_s *volume;
+  FAR struct nxffs_ofile_s *ofile;
+  int ret = -ENOSYS;
+
+  fvdbg("Closing\n");
+
+  /* Sanity checks */
+
+  DEBUGASSERT(filep->f_priv != NULL && filep->f_inode != NULL);
+
+  /* Recover the open file state from the struct file instance */
+
+  ofile = (FAR struct nxffs_ofile_s *)filep->f_priv;
+
+  /* Recover the volume state from the open file */
+
+  volume = (FAR struct nxffs_volume_s *)filep->f_inode->i_private;
+  DEBUGASSERT(volume != NULL);
+
+  /* Get exclusive access to the volume.  Note that the volume exclsem
+   * protects the open file list.
+   */
+
+  ret = sem_wait(&volume->exclsem);
+  if (ret != OK)
+    {
+      ret = -errno;
+      fdbg("sem_wait failed: %d\n", ret);
+      goto errout;
+    }
+
+  /* Decrement the reference count on the open file */
+
+  if (ofile->crefs == 1)
+    {
+      /* Decrementing the reference count would take it zero.  Time to
+       * delete the open file state.
+       */
+
+      nxffs_freeofile(ofile);
+    }
+  else
+    {
+      /* Just decrement the reference count */
+
+      ofile->crefs--;
+    }
+
+  filep->f_priv = NULL;
+  ret = OK;
+
+  sem_post(&volume->exclsem);
+errout:
+  return ret;
+}