close() now does not truncate the file.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@2821 a1c6a512-1295-4272-9138-f99709370657

3 files changed, 57 insertions, 24 deletions

diff --git a/firmware/common/file.c b/firmware/common/file.c
index 1dd71d98ae..b2c2644725 100644
--- a/firmware/common/file.c
+++ b/firmware/common/file.c
@@ -38,7 +38,7 @@
 struct filedesc {
     unsigned char cache[SECTOR_SIZE];
     int cacheoffset;
-    int fileoffset;
+    unsigned int fileoffset;
     int size;
     struct fat_file fatfile;
     bool busy;
@@ -178,7 +178,7 @@ int close(int fd)
         }
         
         /* tie up all loose ends */
-        fat_closewrite(&(openfiles[fd].fatfile), openfiles[fd].fileoffset);
+        fat_closewrite(&(openfiles[fd].fatfile), openfiles[fd].size);
     }
     openfiles[fd].busy = false;
     return rc;
@@ -191,7 +191,21 @@ int remove(const char* name)
     if ( fd < 0 )
         return fd;
 
+    rc = fat_truncate(&(openfiles[fd].fatfile));
+    if ( rc < 0 ) {
+        DEBUGF("Failed truncating file\n");
+        errno = EIO;
+        return -1;
+    }
+
     rc = fat_remove(&(openfiles[fd].fatfile));
+    if ( rc < 0 ) {
+        DEBUGF("Failed removing file\n");
+        errno = EIO;
+        return -2;
+    }
+
+    openfiles[fd].size = 0;
 
     close(fd);
 
@@ -259,7 +273,7 @@ static int readwrite(int fd, void* buf, int count, bool write)
         if ( rc < 0 ) {
             DEBUGF("Failed read/writing %d sectors\n",sectors);
             errno = EIO;
-            return -2;
+            return -3;
         }
         else {
             if ( rc > 0 ) {
@@ -278,10 +292,30 @@ static int readwrite(int fd, void* buf, int count, bool write)
             openfiles[fd].cacheoffset = -1;
         }
     }
+    openfiles[fd].fileoffset += nread;
+    nread = 0;
 
     /* any tail bytes? */
     if ( count ) {
         if (write) {
+            /* sector is only partially filled. copy-back from disk */
+            int rc;
+            LDEBUGF("Copy-back tail cache\n");
+            rc = fat_readwrite(&(openfiles[fd].fatfile), 1,
+                               openfiles[fd].cache, false );
+            if ( rc < 0 ) {
+                DEBUGF("Failed reading\n");
+                errno = EIO;
+                return -4;
+            }
+            /* seek back one sector to put file position right */
+            rc = fat_seek(&(openfiles[fd].fatfile), 
+                          openfiles[fd].fileoffset / SECTOR_SIZE);
+            if ( rc < 0 ) {
+                DEBUGF("fat_seek() failed\n");
+                errno = EIO;
+                return -5;
+            }
             memcpy( openfiles[fd].cache, buf + nread, count );
         }
         else {
@@ -289,7 +323,7 @@ static int readwrite(int fd, void* buf, int count, bool write)
                                &(openfiles[fd].cache),false) < 1 ) {
                 DEBUGF("Failed caching sector\n");
                 errno = EIO;
-                return -1;
+                return -6;
             }
             memcpy( buf + nread, openfiles[fd].cache, count );
         }
diff --git a/firmware/drivers/fat.c b/firmware/drivers/fat.c
index 47bfd1afef..74bdbd3491 100644
--- a/firmware/drivers/fat.c
+++ b/firmware/drivers/fat.c
@@ -167,7 +167,7 @@ static unsigned int getcurrdostime(unsigned short *dosdate,
                                    unsigned short *dostime,
                                    unsigned char *dostenth);
 static int create_dos_name(unsigned char *name, unsigned char *newname);
-static int find_free_cluster(int start);
+static unsigned int find_free_cluster(unsigned int start);
 #endif
 
 #define FAT_CACHE_SIZE 0x20
@@ -438,10 +438,10 @@ static void *cache_fat_sector(int fatsector)
     return sectorbuf;
 }
 
-static int find_free_cluster(int startcluster)
+static unsigned int find_free_cluster(unsigned int startcluster)
 {
-    int sector = startcluster / CLUSTERS_PER_FAT_SECTOR;
-    int offset = startcluster % CLUSTERS_PER_FAT_SECTOR;
+    unsigned int sector = startcluster / CLUSTERS_PER_FAT_SECTOR;
+    unsigned int offset = startcluster % CLUSTERS_PER_FAT_SECTOR;
     int i;
 
     /* don't waste time scanning if the disk is already full */
@@ -511,7 +511,7 @@ static int update_fat_entry(unsigned int entry, unsigned int val)
     return 0;
 }
 
-static int read_fat_entry(int entry)
+static int read_fat_entry(unsigned int entry)
 {
     int sector = entry / CLUSTERS_PER_FAT_SECTOR;
     int offset = entry % CLUSTERS_PER_FAT_SECTOR;
@@ -998,24 +998,23 @@ int fat_create_file(char* name,
     return err;
 }
 
-int fat_closewrite(struct fat_file *file, int size)
+int fat_truncate(struct fat_file *file)
 {
-    int next, last = file->lastcluster;
-    int endcluster = last;
-
-    LDEBUGF("fat_closewrite(size=%d, last=%x)\n",size, last);
-
     /* truncate trailing clusters */
-    last = get_next_cluster(last);
+    int next;
+    int last = get_next_cluster(file->lastcluster);
     while ( last && last != FAT_EOF_MARK ) {
         next = get_next_cluster(last);
         update_fat_entry(last,0);
         last = next;
     }
 
-    /* if no cluster was written, size is 0 */
-    if (!endcluster)
-        size = 0;
+    return 0;
+}
+
+int fat_closewrite(struct fat_file *file, int size)
+{
+    LDEBUGF("fat_closewrite(size=%d)\n",size);
 
     if (!size) {
         /* empty file */
@@ -1024,18 +1023,17 @@ int fat_closewrite(struct fat_file *file, int size)
             file->firstcluster = 0;
         }
     }
-    else
-        update_fat_entry(endcluster, FAT_EOF_MARK);
 
     if (file->dirsector)
         update_dir_entry(file, size);
     flush_fat();
 
 #ifdef TEST_FAT
-    {
+    if ( file->firstcluster ) {
         /* debug */
         int count = 0;
         int len;
+        int next;
         for ( next = file->firstcluster; next;
               next = get_next_cluster(next) )
             LDEBUGF("cluster %d: %x\n", count++, next);
@@ -1213,7 +1211,7 @@ int fat_readwrite( struct fat_file *file, int sectorcount,
     return i;
 }
 
-int fat_seek(struct fat_file *file, int seeksector )
+int fat_seek(struct fat_file *file, unsigned int seeksector )
 {
     int clusternum=0, sectornum=0, sector=0;
     int cluster = file->firstcluster;
diff --git a/firmware/drivers/fat.h b/firmware/drivers/fat.h
index 6ed68ad8d8..b23d8dfa08 100644
--- a/firmware/drivers/fat.h
+++ b/firmware/drivers/fat.h
@@ -79,8 +79,9 @@ extern int fat_create_file(char* name,
 extern int fat_readwrite(struct fat_file *ent, int sectorcount, 
                          void* buf, bool write );
 extern int fat_closewrite(struct fat_file *ent, int size);
-extern int fat_seek(struct fat_file *ent, int sector );
+extern int fat_seek(struct fat_file *ent, unsigned int sector );
 extern int fat_remove(struct fat_file *ent);
+extern int fat_truncate(struct fat_file *ent);
 
 extern int fat_opendir(struct fat_dir *ent, unsigned int currdir);
 extern int fat_getnext(struct fat_dir *ent, struct fat_direntry *entry);