Fix several problems with accessing FAT filesystems

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@758 42af7a65-404d-4744-a932-0658087f49c3

ChangeLog

@@ -353,11 +353,14 @@
 	* Add configuration for the ZiLOG z8f64200100kit development kit, Z8F6423 part.
 	* Add configuration for the ZiLOG ez80f0910200kitg development kit, EZ80F091 part.
 	* Correct critical list handling errors in task shutdown logic: One in timer
-	  deletion logic (timer_delete.c) and one in stream logic (lib_init.c).
+	  deletion logic (timer_delete.c) and one in stream logic (lib_init.c) reported
+	  by kwonsk.
 
 0.3.11 2008-xx-xx Gregory Nutt <spudmonkey@racsa.co.cr>
 
-	* Add support for recursive mutexes.
+	* FEATURE: Add support for recursive mutexes.
 	* BUGFIX: Eliminate a memory leak -- contained watchdog instance was not
-	  being deleted with a POSIX timer was deleted.
+	  being deleted with a POSIX timer was deleted reported by kwonsk.
-	* BUGFIX: Eliminate a deadlock condition in opendir().
+	* BUGFIX: Eliminate a deadlock condition in opendir() reported by kwonsk.
+	* BUGFIX: Fix several FAT filesystem problems reported by kwonsk (Changes
+	  not yet verified).

Documentation/NuttX.html

@@ -979,7 +979,8 @@ nuttx-0.3.10 2008-05-15 Gregory Nutt <spudmonkey@racsa.co.cr>
 	* Add configuration for the ZiLOG z8f64200100kit development kit, Z8F6423 part.
 	* Add configuration for the ZiLOG ez80f0910200kitg development kit, EZ80F091 part.
 	* Correct critical list handling errors in task shutdown logic: One in timer
-	  deletion logic (timer_delete.c) and one in stream logic (lib_init.c).
+	  deletion logic (timer_delete.c) and one in stream logic (lib_init.c) reported
+	  by kwonsk.
 
 pascal-0.1.2 2008-02-10 Gregory Nutt <spudmonkey@racsa.co.cr>
 
@@ -1007,10 +1008,12 @@ buildroot-0.1.0 2007-03-09 &lt;spudmonkey@racsa.co.cr&gt
 <pre><ul>
 nuttx-0.3.11 2008-xx-xx Gregory Nutt &lt;spudmonkey@racsa.co.cr&gt;
 
-	* Add support for recursive mutexes.
+	* FEATURE: Add support for recursive mutexes.
 	* BUGFIX: Eliminate a memory leak -- contained watchdog instance was not
-	  being deleted with a POSIX timer was deleted.
+	  being deleted with a POSIX timer was deleted reported by kwonsk.
-	* BUGFIX: Eliminate a deadlock condition in opendir().
+	* BUGFIX: Eliminate a deadlock condition in opendir() reported by kwonsk.
+	* BUGFIX: Fix several FAT filesystem problems reported by kwonsk (Changes
+	  not yet verified).
 
 pascal-0.1.3 2008-xx-xx Gregory Nutt &lt;spudmonkey@racsa.co.cr&gt;
 

fs/fs_fat32.c

@@ -1,12 +1,13 @@
 /****************************************************************************
  * fs_fat32.c
  *
- *   Copyright (C) 2007 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * References:
  *   Microsoft FAT documentation
- *   FAT implementation 'Copyright (C) 2007, ChaN, all right reserved.'
+ *   Some good ideas were leveraged from the FAT implementation:
+ *     'Copyright (C) 2007, ChaN, all right reserved.'
  *     which has an unrestricted license.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -19,7 +20,7 @@
  *    notice, this list of conditions and the following disclaimer in
  *    the documentation and/or other materials provided with the
  *    distribution.
- * 3. Neither the name Gregory Nutt nor the names of its contributors may be
+ * 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.
  *
@@ -466,11 +467,13 @@ static ssize_t fat_read(FAR struct file *filp, char *buffer, size_t buflen)
    */
 
   readsize   = 0;
+  readsector = ff->ff_currentsector;
   while (buflen > 0)
     {
       /* Get offset into the sector where we begin the read */
 
       int sectorindex = ff->ff_position & SEC_NDXMASK(fs);
+      bytesread = 0;
 
       /* Check if the current read stream happens to lie on a
        * sector boundary.
@@ -523,8 +526,9 @@ static ssize_t fat_read(FAR struct file *filp, char *buffer, size_t buflen)
               /* Setup to read the first sector from the new cluster */
 
               ff->ff_currentcluster   = cluster;
-              readsector              = fat_cluster2sector(fs, cluster);
               ff->ff_sectorsincluster = fs->fs_fatsecperclus;
+              readsector              = fat_cluster2sector(fs, cluster);
+            }
         }
 
       /* Check if the user has provided a buffer large enough to
@@ -562,6 +566,7 @@ static ssize_t fat_read(FAR struct file *filp, char *buffer, size_t buflen)
             }
 
           ff->ff_sectorsincluster -= nsectors - 1;
+          ff->ff_currentsector     = readsector + nsectors - 1;
           bytesread                = nsectors * fs->fs_hwsectorsize;
         }
       else
@@ -586,6 +591,7 @@ static ssize_t fat_read(FAR struct file *filp, char *buffer, size_t buflen)
             }
 
           memcpy(userbuffer, &ff->ff_buffer[sectorindex], bytesread);
+          ff->ff_currentsector = readsector;
         }
 
       /* Set up for the next sector read */
@@ -595,7 +601,6 @@ static ssize_t fat_read(FAR struct file *filp, char *buffer, size_t buflen)
       readsize        += bytesread;
       buflen          -= bytesread;
     }
-    }
 
   fat_semgive(fs);
   return readsize;
@@ -665,6 +670,7 @@ static ssize_t fat_write(FAR struct file *filp, const char *buffer,
    */
 
   byteswritten = 0;
+  writesector = ff->ff_currentsector;
   while (buflen > 0)
     {
       /* Get offset into the sector where we begin the read */
@@ -744,8 +750,8 @@ static ssize_t fat_write(FAR struct file *filp, const char *buffer,
               /* Setup to write the first sector from the new cluster */
 
               ff->ff_currentcluster   = cluster;
-              writesector             = fat_cluster2sector(fs, cluster);
               ff->ff_sectorsincluster = fs->fs_fatsecperclus;
+              writesector             = fat_cluster2sector(fs, cluster);
             }
         }
 
@@ -792,6 +798,7 @@ static ssize_t fat_write(FAR struct file *filp, const char *buffer,
             }
 
           ff->ff_sectorsincluster -= nsectors - 1;
+          ff->ff_currentsector     = writesector + nsectors - 1;
           writesize                = nsectors * fs->fs_hwsectorsize;
           ff->ff_bflags           |= FFBUFF_MODIFIED;
         }
@@ -1257,12 +1264,14 @@ static int fat_opendir(struct inode *mountpt, const char *relpath, struct intern
 
   if (dirinfo.fd_entry == NULL)
     {
-      /* Handler the FAT12/16 root directory */
+      /* Handle the FAT12/16/32 root directory using the values setup by
+       * fat_finddirentry() above.
+       */
 
-      dir->u.fat.fd_startcluster = 0;
+      dir->u.fat.fd_startcluster = dirinfo.dir.fd_startcluster;
-      dir->u.fat.fd_currcluster  = 0;
+      dir->u.fat.fd_currcluster  = dirinfo.dir.fd_currcluster;
-      dir->u.fat.fd_currsector   = fs->fs_rootbase;
+      dir->u.fat.fd_currsector   = dirinfo.dir.fd_currsector;
-      dir->u.fat.fd_index        = 2;
+      dir->u.fat.fd_index        = dirinfo.dir.fd_index;
     }
 
   /* This is not the root directory.  Verify that it is some kind of directory */
@@ -1307,7 +1316,7 @@ static int fat_readdir(struct inode *mountpt, struct internal_dir_s *dir)
   ubyte                  *direntry;
   ubyte                   ch;
   ubyte                   attribute;
-  int                     ret;
+  int                     ret = OK;
 
   /* Sanity checks */
 
@@ -1380,7 +1389,8 @@ static int fat_readdir(struct inode *mountpt, struct internal_dir_s *dir)
 
       if (fat_nextdirentry(fs, &dir->u.fat) != OK)
         {
-          dir->u.fat.fd_currsector = 0;
+          ret = -ENOENT;
+          goto errout_with_semaphore;
         }
     }
 
@@ -1389,7 +1399,7 @@ static int fat_readdir(struct inode *mountpt, struct internal_dir_s *dir)
 
 errout_with_semaphore:
   fat_semgive(fs);
-  return ERROR;
+  return ret;
 }
 
 /****************************************************************************
@@ -1423,13 +1433,23 @@ static int fat_rewinddir(struct inode *mountpt, struct internal_dir_s *dir)
 
   /* Check if this is the root directory */
 
-  if (dir->u.fat.fd_startcluster == 0)
+  if (fs->fs_type != FSTYPE_FAT32 &&
+      dir->u.fat.fd_startcluster == 0)
     {
-      /* Handler the FAT12/16 root directory */
+      /* Handle the FAT12/16 root directory */
 
       dir->u.fat.fd_currcluster  = 0;
       dir->u.fat.fd_currsector   = fs->fs_rootbase;
-      dir->u.fat.fd_index        = 2;
+      dir->u.fat.fd_index        = 0;
+    }
+  else if (fs->fs_type == FSTYPE_FAT32 &&
+           dir->u.fat.fd_startcluster == fs->fs_rootbase)
+    {
+      /* Handle the FAT32 root directory */
+
+      dir->u.fat.fd_currcluster = dir->u.fat.fd_startcluster;
+      dir->u.fat.fd_currsector  = fat_cluster2sector(fs, fs->fs_rootbase);
+      dir->u.fat.fd_index       = 0;
     }
 
   /* This is not the root directory */
@@ -2111,9 +2131,13 @@ static int fat_stat(struct inode *mountpt, const char *relpath, struct stat *buf
       goto errout_with_semaphore;
     }
 
+  memset(buf, 0, sizeof(struct stat));
   if (!dirinfo.fd_entry)
     {
-      ret = -ENOENT;
+      /* It's directory name of mount point */
+
+      buf->st_mode = S_IFDIR|S_IROTH|S_IRGRP|S_IRUSR|S_IWOTH|S_IWGRP|S_IWUSR;
+      ret = OK;
       goto errout_with_semaphore;
     }
 
@@ -2130,7 +2154,6 @@ static int fat_stat(struct inode *mountpt, const char *relpath, struct stat *buf
    * by everyone but may be writeable by no-one.
    */
 
-  memset(buf, 0, sizeof(struct stat));
   buf->st_mode = S_IROTH|S_IRGRP|S_IRUSR;
   if ((attribute & FATATTR_READONLY) == 0)
     {

fs/fs_fat32util.c

@@ -6,7 +6,8 @@
  *
  * References:
  *   Microsoft FAT documentation
- *   FAT implementation 'Copyright (C) 2007, ChaN, all right reserved.'
+ *   Some good ideas were leveraged from the FAT implementation:
+ *     'Copyright (C) 2007, ChaN, all right reserved.'
  *     which has an unrestricted license.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -1340,7 +1341,7 @@ int fat_nextdirentry(struct fat_mountpt_s *fs, struct fs_fatdir_s *dir)
    * been examined.
    */
 
-  if (ndx >= DIRSEC_NDIRS(fs))
+  if ((ndx & (DIRSEC_NDIRS(fs)-1)) == 0)
     {
       /* Yes, then we will have to read the next sector */
 
@@ -1352,7 +1353,7 @@ int fat_nextdirentry(struct fat_mountpt_s *fs, struct fs_fatdir_s *dir)
 
       if (!dir->fd_currcluster)
         {
-          /* For FAT12/13, the boot record tells us number of 32-bit directories
+          /* For FAT12/16, the boot record tells us number of 32-bit directories
            * that are contained in the root directory.  This should correspond to
            * an even number of sectors.
            */
@@ -1381,7 +1382,7 @@ int fat_nextdirentry(struct fat_mountpt_s *fs, struct fs_fatdir_s *dir)
            * has been examined.
            */
 
-          if (sector >= fs->fs_fatsecperclus)
+          if ((sector & (fs->fs_fatsecperclus-1)) == 0)
             {
               /* Get next cluster */