yaffs direct: Handle forced unmount
authorCharles Manning <cdhmanning@gmail.com>
Sun, 14 Nov 2010 23:16:21 +0000 (12:16 +1300)
committerCharles Manning <cdhmanning@gmail.com>
Sun, 14 Nov 2010 23:16:21 +0000 (12:16 +1300)
Reading and writing need to check whether the device has been remounted
read-only or unmounted in a different thread.

Signed-off-by: Charles Manning <cdhmanning@gmail.com>
direct/yaffsfs.c

index aa8d74d..28af280 100644 (file)
@@ -31,7 +31,8 @@
 #define YAFFSFS_RW_SIZE  (1<<YAFFSFS_RW_SHIFT)
 
 /* Some forward references */
-static struct yaffs_obj *yaffsfs_FindObject(struct yaffs_obj *relativeDirectory, const YCHAR *path, int symDepth, int getEquiv);
+static struct yaffs_obj *yaffsfs_FindObject(struct yaffs_obj *relativeDirectory,
+                       const YCHAR *path, int symDepth, int getEquiv);
 static void yaffsfs_RemoveObjectCallback(struct yaffs_obj *obj);
 
 unsigned int yaffs_wr_attempts;
@@ -870,7 +871,16 @@ int yaffsfs_do_read(int fd, void *vbuf, unsigned int nbyte, int isPread, int off
                        nToRead = YAFFSFS_RW_SIZE - (pos & (YAFFSFS_RW_SIZE -1));
                        if(nToRead > nbyte)
                                nToRead = nbyte;
-                       nRead = yaffs_file_rd(obj,buf,pos,nToRead);
+
+                       /* Tricky bit... 
+                        * Need to reverify object in case the device was
+                        * unmounted in another thread.
+                        */
+                       obj = yaffsfs_GetHandleObject(fd);
+                       if(!obj)
+                               nRead = 0;
+                       else
+                               nRead = yaffs_file_rd(obj,buf,pos,nToRead);
 
                        if(nRead > 0){
                                totalRead += nRead;
@@ -953,11 +963,21 @@ int yaffsfs_do_write(int fd, const void *vbuf, unsigned int nbyte, int isPwrite,
                yaffsfs_GetHandle(fd);
                pos = startPos;
                while(nbyte > 0) {
+
                        nToWrite = YAFFSFS_RW_SIZE - (pos & (YAFFSFS_RW_SIZE -1));
                        if(nToWrite > nbyte)
                                nToWrite = nbyte;
 
-                       nWritten = yaffs_wr_file(obj,buf,pos,nToWrite,write_trhrough);
+                       /* Tricky bit... 
+                        * Need to reverify object in case the device was
+                        * remounted or unmounted in another thread.
+                        */
+                       obj = yaffsfs_GetHandleObject(fd);
+                       if(!obj || obj->my_dev->read_only)
+                               nWritten = 0;
+                       else
+                               nWritten = yaffs_wr_file(obj,buf,pos,nToWrite,
+                                                       write_trhrough);
                        if(nWritten > 0){
                                totalWritten += nWritten;
                                pos += nWritten;
@@ -1942,7 +1962,8 @@ int yaffs_unmount2(const YCHAR *path, int force)
                        yaffs_checkpoint_save(dev);
 
                        for(i = inUse = 0; i < YAFFSFS_N_HANDLES && !inUse; i++){
-                               if(yaffsfs_handle[i].useCount > 0 && yaffsfs_inode[yaffsfs_handle[i].inodeId].iObj->my_dev == dev)
+                               if(yaffsfs_handle[i].useCount > 0 && 
+                               yaffsfs_inode[yaffsfs_handle[i].inodeId].iObj->my_dev == dev)
                                        inUse = 1; /* the device is in use, can't unmount */
                        }