Changeset b12ca16 in mainline for uspace/lib/ext4/libext4_bitmap.c

Timestamp:

2011-11-18T15:30:24Z (13 years ago)

Author:

Frantisek Princ <frantisek.princ@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

d5ba17f

Parents:

e18de3c

Message:

improved block allocator - but has some bugs

File:

• uspace/lib/ext4/libext4_bitmap.c (modified) (2 diffs)

uspace/lib/ext4/libext4_bitmap.c

@@ -76 +76 @@
 }
 
-int ext4_bitmap_find_free_byte_and_set_bit(uint8_t *bitmap, uint32_t start, uint32_t *index, uint32_t size)
+int ext4_bitmap_find_free_byte_and_set_bit(uint8_t *bitmap, uint32_t start, uint32_t *index, uint32_t max)
 {
-        uint8_t *pos = bitmap + (start / 8) + 1;
+        uint32_t idx;
+        if (start % 8) {
+                idx = start + (8 - (start % 8));
+        } else {
+                idx = start;
+        }
 
-        while (pos < bitmap + size) {
+        uint8_t *pos = bitmap + (idx / 8);
+
+        while (idx < max) {
+
                 if (*pos == 0) {
                         *pos |= 1;
 
-                        *index = (pos - bitmap) * 8;
+                        *index = idx;
                         return EOK;
                 }
 
+                idx += 8;
                 ++pos;
         }
 
         return ENOSPC;
-
 }
 
-int ext4_bitmap_find_free_bit_and_set(uint8_t *bitmap, uint32_t start, uint32_t *index, uint32_t size)
+int ext4_bitmap_find_free_bit_and_set(uint8_t *bitmap, uint32_t start_idx,
+                uint32_t *index, uint32_t max)
 {
-        uint8_t *pos = bitmap + (start / 8);
-        int i;
-        uint8_t value, new_value;
+        uint8_t *pos = bitmap + (start_idx / 8);
+        uint32_t idx = start_idx;
+        bool byte_part = false;
 
-        while (pos < bitmap + size) {
+        // Check the rest of byte
+        while ((idx % 8) != 0) {
+                byte_part = true;
+
+                if (*pos & (1 << (idx % 8))) {
+                        *pos |= (1 << (idx % 8));
+                        *index = idx;
+                        return EOK;
+                }
+
+                ++idx;
+        }
+
+        if (byte_part) {
+                ++pos;
+        }
+
+        while (idx < max) {
+
                 if ((*pos & 255) != 255) {
                         // free bit found
@@ -107 +134 @@
                 }
 
+                idx += 8;
                 ++pos;
         }
 
-        // Check the byte containing start
-        if (pos == bitmap + (start / 8)) {
-                for (i = start % 8; i < 8; ++i) {
-                        value = *pos;
-                        if ((value & (1 << i)) == 0) {
+
+        if (idx < max) {
+                for (uint8_t i = 0; i < 8; ++i) {
+                        if ((*pos & (1 << i)) == 0) {
                                 // free bit found
-                                new_value = value | (1 << i);
-                                *pos = new_value;
-                                *index = (pos - bitmap) * 8 + i;
+                                *pos |=  (1 << i);
+                                *index = idx;
                                 return EOK;
                         }
-                }
-        }
-
-        if (pos < bitmap + size) {
-
-                for(i = 0; i < 8; ++i) {
-                        value = *pos;
-
-                        if ((value & (1 << i)) == 0) {
-                                // free bit found
-                                new_value = value | (1 << i);
-                                *pos = new_value;
-                                *index = (pos - bitmap) * 8 + i;
-                                return EOK;
-                        }
+                        idx++;
                 }
         }