Changeset 610 for trunk/kernel/mm/mapper.h

Timestamp:

Dec 27, 2018, 7:38:58 PM (5 years ago)

Author:

alain

Message:

Fix several bugs in VFS to support the following
ksh commandis : cp, mv, rm, mkdir, cd, pwd

File:

• trunk/kernel/mm/mapper.h (modified) (4 diffs)

trunk/kernel/mm/mapper.h

@@ -45 +45 @@
  * - The leaves are pointers on physical page descriptors, dynamically allocated
  *   in the local cluster.
- * - In a given cluster, a mapper is a "private" structure: a thread accessing the mapper
- *   must be running in the cluster containing it (can be a local thread or a RPC thread).
- * - The mapper is protected by a blocking "rwlock", to support several simultaneous
- *   readers, and only one writer. This lock implement a busy waiting policy.
- * - The mapper_get_page() function that return a page descriptor pointer from a page
- *   index in file is in charge of handling the miss on the mapper cache.
+ * - The mapper is protected by a "remote_rwlock", to support several simultaneous 
+ *   "readers", and only one "writer".
+ * - A "reader" thread, calling the mapper_remote_get_page() function to get a page 
+ *   descriptor pointer from the page index in file, can be remote (running in any cluster). 
+ * - A "writer" thread, calling the mapper_handle_miss() function to handle a page miss
+ *   must be local (running in the mapper cluster).
  * - The vfs_mapper_move_page() function access the file system to handle a mapper miss,
  *   or update a dirty page on device.
- * - The vfs_mapper_load_all() functions is used to load all pages of a given file 
- *   or directory into the mapper.
+ * - The vfs_mapper_load_all() functions is used to load all pages of a directory 
+ *   into the mapper (prefetch).
  * - the mapper_move_user() function is used to move data to or from an user buffer.
  *   This user space buffer can be physically distributed in several clusters.
@@ -137 +137 @@
 
 /*******************************************************************************************
- * This function move data between a local mapper, and a distributed user buffer.
- * It must be called by a thread running in cluster containing the mapper.
+ * This function move data between a remote mapper, dentified by the <mapper_xp> argument,
+ * and a distributed user buffer. It can be called by a thread running in any cluster.
  * It is called by the vfs_user_move() to implement sys_read() and sys_write() syscalls.
  * If required, the data transfer is split in "fragments", where one fragment contains 
@@ -144 +144 @@
  * It uses "hal_uspace" accesses to move a fragment to/from the user buffer.
  * In case of write, the dirty bit is set for all pages written in the mapper.
- * The mapper being an extendable cache, it is automatically extended when required
- * for both read and write accesses. 
+ * The mapper being an extendable cache, it is automatically extended when required.
  * The "offset" field in the file descriptor, and the "size" field in inode descriptor
  * are not modified by this function.
  *******************************************************************************************
- * @ mapper       : local pointer on mapper.
+ * @ mapper_xp    : extended pointer on mapper.
  * @ to_buffer    : mapper -> buffer if true / buffer -> mapper if false.
  * @ file_offset  : first byte to move in file.
@@ -156 +155 @@
  * returns O if success / returns -1 if error.
  ******************************************************************************************/
-error_t mapper_move_user( mapper_t * mapper,
+error_t mapper_move_user( xptr_t     mappe_xp,
                           bool_t     to_buffer,
                           uint32_t   file_offset,