umount and fat fixes

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@227 42af7a65-404d-4744-a932-0658087f49c3

examples/mount/mount_main.c

@@ -108,10 +108,21 @@ int user_start(int argc, char *argv[])
         }
       else
         {
+          char buffer[128];
+          int nbytes = read(fd, buffer, 128);
+          if (nbytes < 0)
+            {
+              printf("main: failed to read from %s, errno=%d\n", g_testfile1, *get_errno_ptr());
+            }
+          else
+          {
+              buffer[127]='\0';
+              printf("main: Read \"%s\" from %s\n", buffer, g_testfile1);
+          }
           close(fd);
         }
 
-      printf("main: opening %s for reading\n", g_testfile2);
+      printf("main: opening %s for writing\n", g_testfile2);
 
       fd = open(g_testfile2, O_WRONLY|O_CREAT|O_TRUNC, 0644);
       if (fd < 0)

fs/fs_fat32.c

@@ -221,8 +221,8 @@
  * Private Function Prototypes
  ****************************************************************************/
 
-static int     fat_open(FAR struct file *filp, const char *rel_path,
-                        int oflags, mode_t mode);
+static int     fat_open(FAR struct file *filp, FAR struct inode *inode,
+                        const char *rel_path, int oflags, mode_t mode);
 static int     fat_close(FAR struct file *filp);
 static ssize_t fat_read(FAR struct file *filp, char *buffer, size_t buflen);
 static ssize_t fat_write(FAR struct file *filp, const char *buffer,
@@ -770,20 +770,62 @@ static int fat_mount(struct fat_mountpt_s *fs, boolean writeable)
  * Name: fat_open
  ****************************************************************************/
 
-static int fat_open(FAR struct file *filp, const char *rel_path,
-                    int oflags, mode_t mode)
+static int fat_open(FAR struct file *filp, FAR struct inode *inode,
+                    const char *rel_path, int oflags, mode_t mode)
 {
-  struct fat_mountpt_s *fs = filp->f_priv;
-  int ret;
+  struct fat_mountpt_s *fs = (struct fat_mountpt_s *)inode->i_private;
+  struct fat_file_s *ff;
+  int ret = OK;
  
   /* Make sure that the mount is still healthy */
+  if (!fs)
+    {
+      ret = -ENOSYS;
+      goto errout;
+    }
 
- ret = fat_checkmount(fs);
+  fat_semtake(fs);
+  ret = fat_checkmount(fs);
   if (ret != OK)
     {
-      return ret;
+      goto errout_with_semaphore;
     }
-  return -ENOSYS;
+
+  /* Allocate a new private instance for the struct file */
+
+  ff = (struct fat_file_s *)malloc(sizeof(struct fat_file_s));
+  if (!ff)
+    {
+      ret = -ENOMEM;
+      goto errout_with_semaphore;
+    }
+
+  /* Find the requested path and open or create the file */
+#warning "Open logic missing"
+
+  /* Initialize the new private instance */
+
+  ff->ff_parent = fs;
+  ff->ff_open   = TRUE;
+
+  /* Then insert the new instance into the mountpoint structure.
+   * It needs to be there (1) to handle error conditions that effect
+   * all files, and (2) to inform the umount logic that we are busy
+   * (but a simple reference count could have done that).
+   */
+
+  ff->ff_next = fs->fs_head;
+  fs->fs_head = ff->ff_next;
+
+  fat_semgive(fs);
+  return OK;
+
+ errout_with_alloc:
+  free(ff);
+ errout_with_semaphore:
+  fat_semgive(fs);
+ errout:
+  return ret;
 }
 
 /****************************************************************************
@@ -792,7 +834,13 @@ static int fat_open(FAR struct file *filp, const char *rel_path,
 
 static int fat_close(FAR struct file *filp)
 {
-  struct fat_mountpt_s *fs = filp->f_priv;
+  struct fat_file_s *ff = filp->f_priv;
+  struct fat_mountpt_s *fs;
+
+  if (!ff || !(fs = ff->ff_parent))
+    {
+      return -EINVAL;
+    }
 
   /* Do not check if the mount is healthy.  We must support closing of
    * the file even when there is healthy mount.
@@ -807,9 +855,15 @@ static int fat_close(FAR struct file *filp)
 
 static ssize_t fat_read(FAR struct file *filp, char *buffer, size_t buflen)
 {
-  struct fat_mountpt_s *fs = filp->f_priv;
+  struct fat_file_s *ff = filp->f_priv;
+  struct fat_mountpt_s *fs;
   int ret;
 
+  if (!ff || !(fs = ff->ff_parent))
+    {
+      return -EINVAL;
+    }
+
   /* Make sure that the mount is still healthy */
 
   ret = fat_checkmount(fs);
@@ -827,9 +881,15 @@ static ssize_t fat_read(FAR struct file *filp, char *buffer, size_t buflen)
 static ssize_t fat_write(FAR struct file *filp, const char *buffer,
                          size_t buflen)
 {
-  struct fat_mountpt_s *fs = filp->f_priv;
+  struct fat_file_s *ff = filp->f_priv;
+  struct fat_mountpt_s *fs;
   int ret;
 
+  if (!ff || !(fs = ff->ff_parent))
+    {
+      return -EINVAL;
+    }
+
   /* Make sure that the mount is still healthy */
 
   ret = fat_checkmount(fs);
@@ -846,9 +906,15 @@ static ssize_t fat_write(FAR struct file *filp, const char *buffer,
 
 static off_t fat_seek(FAR struct file *filp, off_t offset, int whence)
 {
-  struct fat_mountpt_s *fs = filp->f_priv;
+  struct fat_file_s *ff = filp->f_priv;
+  struct fat_mountpt_s *fs;
   int ret;
 
+  if (!ff || !(fs = ff->ff_parent))
+    {
+      return -EINVAL;
+    }
+
   /* Make sure that the mount is still healthy */
 
   ret = fat_checkmount(fs);
@@ -865,9 +931,15 @@ static off_t fat_seek(FAR struct file *filp, off_t offset, int whence)
 
 static int fat_ioctl(FAR struct file *filp, int cmd, unsigned long arg)
 {
-  struct fat_mountpt_s *fs = filp->f_priv;
+  struct fat_file_s *ff = filp->f_priv;
+  struct fat_mountpt_s *fs;
   int ret;
 
+  if (!ff || !(fs = ff->ff_parent))
+    {
+      return -EINVAL;
+    }
+
   /* Make sure that the mount is still healthy */
 
   ret = fat_checkmount(fs);

fs/fs_fat32.h

@@ -196,6 +196,7 @@ struct fat_mountpt_s
 struct fat_file_s
 {
   struct fat_file_s *ff_next;     /* File structures are retained in a singly linked list */
+  struct fat_mountpt_s *ff_parent;
   boolean  ff_open;               /* TRUE: The file is (still) open */
 };
 

fs/fs_inoderemove.c

@@ -112,9 +112,9 @@ STATUS inode_remove(const char *path)
   FAR struct inode *left;
   FAR struct inode *parent;
 
-  if (*path && path[0] == '/')
+  if (!*path || path[0] != '/')
     {
-      return ERROR;
+      return -EINVAL;
     }
 
   /* Find the node to delete */

fs/fs_open.c

@@ -154,7 +154,7 @@ int open(const char *path, int oflags, ...)
       if (INODE_IS_MOUNTPT(inode))
         {
           status = inode->u.i_mops->open((FAR struct file*)&list->fl_files[fd],
-                                         relpath, oflags, mode);
+                                         inode, relpath, oflags, mode);
         }
       else
         {

fs/fs_umount.c

@@ -104,12 +104,11 @@ int umount(const char *target)
 
   /* Find the mountpt */
 
-  inode_semtake();
   mountpt_inode = inode_find(target, NULL);
   if (!mountpt_inode)
     {
       errcode = ENOENT;
-      goto errout_with_semaphore;
+      goto errout;
     }
 
   /* Verify that the inode is a mountpoint */
@@ -137,18 +136,19 @@ int umount(const char *target)
    * performed, or a negated error code on a failure.
    */
 
+  inode_semtake(); /* Hold the semaphore through the unbind logic */
   status = mountpt_inode->u.i_mops->unbind( mountpt_inode->i_private );
   if (status < 0)
     {
       /* The inode is unhappy with the blkdrvr for some reason */
 
       errcode = -status;
-      goto errout_with_mountpt;
+      goto errout_with_semaphore;
     }
   else if (status > 0)
     {
       errcode = EBUSY;
-      goto errout_with_mountpt;
+      goto errout_with_semaphore;
     }
 
   /* Successfully unbound */
@@ -157,17 +157,20 @@ int umount(const char *target)
 
   /* Remove the inode */
 
+  inode_semgive(); /* Need to release for inode_release */
   inode_release(mountpt_inode);
+
+  inode_semtake(); /* Need to hold for inode_remove */
   status = inode_remove(target);
   inode_semgive();
   return status;
 
   /* A lot of goto's!  But they make the error handling much simpler */
 
- errout_with_mountpt:
-  inode_release(mountpt_inode);
  errout_with_semaphore:
   inode_semgive();
+ errout_with_mountpt:
+  inode_release(mountpt_inode);
  errout:
   *get_errno_ptr() = errcode;
   return ERROR;

include/nuttx/fs.h

@@ -117,11 +117,13 @@ struct inode;
 struct mountpt_operations
 {
   /* The mountpoint open method differs from the driver open method
-   * because it receives the relative path into the mountpoint.
+   * because it receives (1) the inode that contains the mountpoint
+   * private data, (2) the relative path into the mountpoint, and (3)
+   * information to manage privileges.
    */
 
-  int     (*open)(FAR struct file *filp, const char *rel_path,
-                  int oflags, mode_t mode);
+  int     (*open)(FAR struct file *filp, FAR struct inode *inode, 
+                  const char *rel_path, int oflags, mode_t mode);
 
   /* The following methods must be identical in signature and position because
    * the struct file_operations and struct mountp_operations are treated like