[svn-r23702] Issue 8380 - H5Zunregister caused seg fault. This is a porting of code from the trunk. It fixes the problem by first iterating

through all opened datasets and groups to see if any of them uses the filter.  If it finds one, the function fails with a message.  
Then the function flushes all opened files.

Tested with h5committest.

1 files changed, 179 insertions, 0 deletions

diff --git a/src/H5Z.c b/src/H5Z.c
index 9f8b59d..abcc468 100644
--- a/src/H5Z.c
+++ b/src/H5Z.c
@@ -22,6 +22,7 @@
 #include "H5private.h"		/* Generic Functions			*/
 #include "H5Dprivate.h"		/* Dataset functions			*/
 #include "H5Eprivate.h"		/* Error handling		  	*/
+#include "H5Fprivate.h"		/* File		  			*/
 #include "H5Iprivate.h"		/* IDs			  		*/
 #include "H5MMprivate.h"	/* Memory management			*/
 #include "H5Oprivate.h"		/* Object headers		  	*/
@@ -45,6 +46,11 @@ typedef struct H5Z_stats_t {
 } H5Z_stats_t;
 #endif /* H5Z_DEBUG */
 
+typedef struct H5Z_object_t {
+    H5Z_filter_t filter_id;     /* ID of the filter we're looking for         */
+    htri_t       found;         /* Whether we find an object using the filter */
+} H5Z_object_t;
+
 /* Enumerated type for dataset creation prelude callbacks */
 typedef enum {
     H5Z_PRELUDE_CAN_APPLY,      /* Call "can apply" callback */
@@ -61,6 +67,8 @@ static H5Z_stats_t	*H5Z_stat_table_g = NULL;
 
 /* Local functions */
 static int H5Z_find_idx(H5Z_filter_t id);
+static int H5Z_get_object_cb(void *obj_ptr, hid_t obj_id, void *key);
+static int H5Z_get_file_cb(void *obj_ptr, hid_t obj_id, void *key);
 
 
 /*-------------------------------------------------------------------------
@@ -406,6 +414,7 @@ herr_t
 H5Z_unregister (H5Z_filter_t id)
 {
     size_t i;                   /* Local index variable */
+    H5Z_object_t object;
     herr_t ret_value=SUCCEED;   /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
@@ -421,6 +430,28 @@ H5Z_unregister (H5Z_filter_t id)
     if (i>=H5Z_table_used_g)
         HGOTO_ERROR(H5E_PLINE, H5E_NOTFOUND, FAIL, "filter is not registered")
 
+    /* Initialize the structure object for iteration */
+    object.filter_id = id;
+    object.found = FALSE;
+
+    /* Iterate through all opened datasets, returns a failure if any of them uses the filter */
+    if(H5I_iterate(H5I_DATASET, H5Z_get_object_cb, &object, FALSE) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_BADITER, FAIL, "iteration failed")
+
+    if(object.found)
+        HGOTO_ERROR(H5E_PLINE, H5E_CANTRELEASE, FAIL, "can't unregister filter because a dataset is still using it")
+
+    /* Iterate through all opened groups, returns a failure if any of them uses the filter */
+    if(H5I_iterate(H5I_GROUP, H5Z_get_object_cb, &object, FALSE) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_BADITER, FAIL, "iteration failed")
+
+    if(object.found)
+        HGOTO_ERROR(H5E_PLINE, H5E_CANTRELEASE, FAIL, "can't unregister filter because a group is still using it")
+
+    /* Iterate through all opened files and flush them */
+    if(H5I_iterate(H5I_FILE, H5Z_get_file_cb, NULL, FALSE) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_BADITER, FAIL, "iteration failed")
+
     /* Remove filter from table */
     /* Don't worry about shrinking table size (for now) */
     HDmemmove(&H5Z_table_g[i],&H5Z_table_g[i+1],sizeof(H5Z_class2_t)*((H5Z_table_used_g-1)-i));
@@ -435,6 +466,112 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5Z_get_object_cb
+ *
+ * Purpose:	The callback function for H5Z_unregister. It iterates 
+ *              through all opened objects.  If the object is a dataset
+ *              or a group and it uses the filter to be unregistered, the 
+ *              function returns TRUE. 
+ *
+ * Return:      TRUE if the object uses the filter.
+ *              FALSE otherwise.
+ *
+ * Programmer:  Raymond Lu
+ *              13 May 2013
+ *
+ *-------------------------------------------------------------------------
+ */
+static int
+H5Z_get_object_cb(void *obj_ptr, hid_t obj_id, void *key)
+{
+    H5I_type_t      id_type;
+    hid_t           ocpl_id;
+    H5P_genplist_t  *plist;                 /* Property list */
+    H5Z_object_t    *object = (H5Z_object_t *)key;
+    htri_t          filter_in_pline = FALSE;
+    int             ret_value = FALSE;    /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    HDassert(obj_ptr);
+
+    if((id_type = H5I_get_type(obj_id)) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "bad object id");
+
+    switch(id_type) {
+        case H5I_GROUP:
+            if((ocpl_id = H5G_get_create_plist((H5G_t *)obj_ptr)) < 0) 
+                HGOTO_ERROR(H5E_ARGS, H5E_CANTGET, FAIL, "can't get group creation property list")
+
+            break;
+
+        case H5I_DATASET:
+            if((ocpl_id = H5D_get_create_plist((H5D_t *)obj_ptr)) < 0) 
+                HGOTO_ERROR(H5E_ARGS, H5E_CANTGET, FAIL, "can't get dataset creation property list")
+                
+            break;
+
+        default:
+            HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "not a valid object")
+    } /* end switch */
+
+    /* Get the plist structure of object creation */
+    if(NULL == (plist = H5P_object_verify(ocpl_id, H5P_OBJECT_CREATE)))
+        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't find object for ID")
+
+    /* Check if the object creation property list uses the filter */
+    if((filter_in_pline = H5P_filter_in_pline(plist, object->filter_id)) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't check filter in pipeline")
+
+    /* H5I_iterate expects TRUE to stop the loop over objects. Stop the loop and let 
+     * H5Z_unregister return failure */ 
+    if(filter_in_pline) {
+        object->found = TRUE;
+        ret_value = TRUE;
+    }
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5F_get_object_cb() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5Z_get_file_cb
+ *
+ * Purpose:	The callback function for H5Z_unregister. It iterates 
+ *              through all opened files and flush them. 
+ *
+ * Return:      FALSE if finishes flushing and moves on
+ *              FAIL if there is an error
+ *
+ * Programmer:  Raymond Lu
+ *              13 May 2013
+ *
+ *-------------------------------------------------------------------------
+ */
+static int
+H5Z_get_file_cb(void *obj_ptr, hid_t UNUSED obj_id, void UNUSED *key)
+{
+    int             ret_value = FALSE;    /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    HDassert(obj_ptr);
+
+    /* Call the flush routine for mounted file hierarchies. Do a global flush 
+     * if the file is opened for write */
+    if(H5F_ACC_RDWR & H5F_INTENT((H5F_t *)obj_ptr)) {
+        if(H5F_flush_mounts((H5F_t *)obj_ptr, H5AC_dxpl_id) < 0)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTFLUSH, FAIL, "unable to flush file hierarchy")
+    } /* end if */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5F_get_file_cb() */
+
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5Zfilter_avail
  *
  * Purpose:	Check if a filter is available
@@ -1275,6 +1412,48 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5Z_filter_in_pline
+ *
+ * Purpose:	Check wheter a filter is in the filter pipeline using the 
+ *              filter ID.  This function is very similar to H5Z_filter_info
+ *
+ * Return:	TRUE   - found filter
+ *              FALSE  - not found
+ *              FAIL   - error
+ *
+ * Programmer:	Raymond Lu
+ *              14 May 2013
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+htri_t
+H5Z_filter_in_pline(const H5O_pline_t *pline, H5Z_filter_t filter)
+{
+    size_t	idx;                    /* Index of filter in pipeline */
+    htri_t      ret_value = TRUE;       /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    assert(pline);
+    assert(filter>=0 && filter<=H5Z_FILTER_MAX);
+
+    /* Locate the filter in the pipeline */
+    for(idx=0; idx<pline->nused; idx++)
+        if(pline->filter[idx].id==filter)
+            break;
+
+    /* Check if the filter was not already in the pipeline */
+    if(idx>=pline->nused)
+	ret_value = FALSE;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5Z_filter_in_pline() */
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5Z_all_filters_avail
  *
  * Purpose:	Verify that all the filters in a pipeline are currently