Initial commit -- seeded with reiserfsprogs 3.x.0j

fsck/segments.c

@@ -0,0 +1,202 @@
+/*
+ * Copyright 1998 Hans Reiser
+ */
+/*#include <stdio.h>
+#include <string.h>*/
+/*#include <asm/bitops.h>
+#include "../include/reiserfs_fs.h"
+#include "../include/reiserfs_fs_sb.h"
+#include "../include/reiserfslib.h"*/
+#include "fsck.h"
+
+
+/* there is a situation, when we overwrite contents of unformatted
+   node with direct item. One unformatted node can be overwritten
+   several times by direct items */
+/*
+struct overwritten_unfm_segment {
+  int ous_begin;
+  int ous_end;
+  struct overwritten_unfm_segment * ous_next;  
+};
+*/
+struct overwritten_unfm {
+  unsigned long ou_unfm_ptr;	/* block number of unfm node */
+  unsigned long ou_dir_id;
+  unsigned long ou_objectid; 	/* key corresponding to an unfm node */
+  unsigned long ou_offset;
+
+  struct overwritten_unfm_segment * ou_segments;	/* list of segmens, than have been overwritten in ths unfm node */
+};
+
+struct overwritten_unfm ** g_overwritten_unfms;
+int g_overwritten_unfms_amount;	/* number of unformatted nodes, which contain direct items */
+
+
+/* adds segment to the single linked list of segments sorted by begin
+   field. Retuns pointer to first element of list */
+static struct overwritten_unfm_segment * add_segment (struct overwritten_unfm_segment * first, int begin, int end)
+{
+  struct overwritten_unfm_segment * new, * next, * prev;
+
+  new = getmem (sizeof (struct overwritten_unfm_segment));
+  new->ous_begin = begin;
+  new->ous_end = end;
+  new->ous_next = 0;
+
+  next = first;
+  prev = 0;
+  while (next) {
+    if (next->ous_begin > begin)
+      break;
+    prev = next;
+    next = next->ous_next;
+  }
+
+  if (prev == 0) {
+    /* insert into head of list */
+    first = new;
+  } else {
+    prev->ous_next = new;
+  }
+  new->ous_next = next;
+  return first;
+}
+
+
+/* input parameter 
+   `list_head` - first element of overlapping segments sorted by left edge
+   `unoverwritten_segment` - returned by previous call of get_unoverwritten_segment or (-2,-2) if called first time
+   */
+/* returns
+   1 and segment unoverwritten by elements of list `list_head`
+   0 if there isno such segment
+   */
+int get_unoverwritten_segment (struct overwritten_unfm_segment * list_head, struct overwritten_unfm_segment * unoverwritten_segment)
+{
+  int end;
+
+  /* look for segment, which has begin field greater than end of previous interval */
+  while (list_head->ous_begin <= unoverwritten_segment->ous_end) {
+    list_head = list_head->ous_next;
+  }
+  /* look for the end of the continuous region covered by otrezkami */
+  end = list_head->ous_end;
+  while (list_head->ous_next) {
+    if (list_head->ous_next->ous_begin > end + 1)
+      /* intreval found */
+      break;
+    if (list_head->ous_next->ous_end > end)
+      end = list_head->ous_next->ous_end;
+    list_head = list_head->ous_next;
+  }
+  /* ok, between segment and segment->next we have an interval (segment->next != 0) */
+  if (list_head->ous_next != 0) {
+    unoverwritten_segment->ous_begin = end + 1;
+    unoverwritten_segment->ous_end = list_head->ous_next->ous_begin - 1;
+    return 1;
+  }
+  return 0;
+}
+
+
+void print_segments (struct overwritten_unfm_segment * list_head)
+{
+  struct overwritten_unfm_segment * cur;
+
+  cur = list_head;
+  while (cur) {
+    printf ("%s%d %d%s", cur == list_head ? "(" : "", cur->ous_begin, cur->ous_end, cur->ous_next ? ", " : ")\n");
+    cur = cur->ous_next;
+  }
+}
+
+
+/* this prepare list of segments to extracting of unoverwritten segments */
+struct overwritten_unfm_segment * find_overwritten_unfm (unsigned long unfm, int length, struct overwritten_unfm_segment * segment_to_init)
+{
+  int i;
+
+  for (i = 0; i < g_overwritten_unfms_amount && g_overwritten_unfms[i] != 0; i ++)
+    if (g_overwritten_unfms[i]->ou_unfm_ptr == unfm) {
+      if (g_overwritten_unfms[i]->ou_segments == 0)
+	die ("find_overwritten_unfm: no segment found");
+      g_overwritten_unfms[i]->ou_segments = add_segment (g_overwritten_unfms[i]->ou_segments, -1, -1);
+      add_segment (g_overwritten_unfms[i]->ou_segments, length, length);
+      segment_to_init->ous_begin = -2;
+      segment_to_init->ous_end = -2;
+      return g_overwritten_unfms[i]->ou_segments;
+    }
+  return 0;
+}
+
+struct overwritten_unfm * look_for_overwritten_unfm (__u32 unfm)
+{
+  int i;
+
+  for (i = 0; i < g_overwritten_unfms_amount && g_overwritten_unfms[i] != 0; i ++)
+    if (g_overwritten_unfms[i]->ou_unfm_ptr == unfm)
+      return g_overwritten_unfms[i];
+    return 0;
+}
+
+#define GROW_BY 10
+struct overwritten_unfm * add_overwritten_unfm (unsigned long unfm, struct item_head * direct_ih)
+{
+  int i;
+
+  for (i = 0; i < g_overwritten_unfms_amount && g_overwritten_unfms[i] != 0; i ++) {
+    if (g_overwritten_unfms[i]->ou_unfm_ptr == unfm)
+      return g_overwritten_unfms[i];
+  }
+
+  if (i == g_overwritten_unfms_amount) {
+    g_overwritten_unfms = expandmem (g_overwritten_unfms, sizeof (struct overwritten_unfm *) * i, 
+				     sizeof (struct overwritten_unfm *) * GROW_BY);
+    g_overwritten_unfms_amount += GROW_BY;
+  }
+  g_overwritten_unfms[i] = getmem (sizeof (struct overwritten_unfm));
+  g_overwritten_unfms[i]->ou_unfm_ptr = unfm;
+  g_overwritten_unfms[i]->ou_dir_id = direct_ih->ih_key.k_dir_id;
+  g_overwritten_unfms[i]->ou_objectid = direct_ih->ih_key.k_objectid;
+  g_overwritten_unfms[i]->ou_offset = get_offset(&direct_ih->ih_key) - (get_offset(&direct_ih->ih_key) - 1) % fs->s_blocksize;
+  return g_overwritten_unfms[i];
+}
+
+
+void save_unfm_overwriting (unsigned long unfm, struct item_head * direct_ih)
+{
+  struct overwritten_unfm * ov_unfm;
+
+  /* add new overwritten unfm or return existing one */
+  ov_unfm = add_overwritten_unfm (unfm, direct_ih);
+  ov_unfm->ou_segments = add_segment (ov_unfm->ou_segments, (get_offset(&direct_ih->ih_key) - 1) % fs->s_blocksize,
+				      (get_offset(&direct_ih->ih_key) - 1) % fs->s_blocksize + ih_item_len (direct_ih) - 1);
+}
+
+
+void free_overwritten_unfms (void)
+{
+  int i;
+
+  for (i = 0; i < g_overwritten_unfms_amount && g_overwritten_unfms[i]; i ++) {
+    /* free all segments */
+    while (g_overwritten_unfms[i]->ou_segments) {
+      struct overwritten_unfm_segment * tmp;
+
+      tmp = g_overwritten_unfms[i]->ou_segments->ous_next;
+      freemem (g_overwritten_unfms[i]->ou_segments);
+      g_overwritten_unfms[i]->ou_segments = tmp;
+    }
+    /* free struct overwritten_unfm */
+    freemem (g_overwritten_unfms[i]);
+  }
+
+  /* free array of pointers to overwritten unfms */
+  if (g_overwritten_unfms)
+    freemem (g_overwritten_unfms);
+}
+
+
+
+