Changeset b2c96093 in mainline for uspace/srv/fs/mfs/mfs_balloc.c

Timestamp:

2013-07-11T15:37:02Z (11 years ago)

Author:

Maurizio Lombardi <m.lombardi85@…>

Branches:

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

Children:

2b3e8840

Parents:

224174f

Message:

mfs: add functions to get the number of free entries in the bitmaps.

File:

• uspace/srv/fs/mfs/mfs_balloc.c (modified) (5 diffs)

uspace/srv/fs/mfs/mfs_balloc.c

@@ -44 +44 @@
 mfs_alloc_bit(struct mfs_instance *inst, uint32_t *idx, bmap_id_t bid);
 
+static int
+mfs_count_free_bits(struct mfs_instance *inst, bmap_id_t bid, uint32_t *free);
+
+
 /**Allocate a new inode.
  *
@@ -102 +106 @@
 
         return mfs_free_bit(inst, zone, BMAP_ZONE);
+}
+
+/** Count the number of free zones
+ *
+ * @param inst          Pointer to the instance structure.
+ * @param zones         Pointer to the memory location where the result
+ *                      will be stored.
+ *
+ * @return              EOK on success or a negative error code.
+ */
+int
+mfs_count_free_zones(struct mfs_instance *inst, uint32_t *zones)
+{
+        return mfs_count_free_bits(inst, BMAP_ZONE, zones);
+}
+
+/** Count the number of free inodes
+ *
+ * @param inst          Pointer to the instance structure.
+ * @param zones         Pointer to the memory location where the result
+ *                      will be stored.
+ *
+ * @return              EOK on success or a negative error code.
+ */
+
+int
+mfs_count_free_inodes(struct mfs_instance *inst, uint32_t *inodes)
+{
+        return mfs_count_free_bits(inst, BMAP_INODE, inodes);
+}
+
+/** Count the number of free bits in a bitmap
+ *
+ * @param inst          Pointer to the instance structure.
+ * @param bid           Type of the bitmap (inode or zone).
+ * @param free          Pointer to the memory location where the result
+ *                      will be stores.
+ *
+ * @return              EOK on success or a negative error code.
+ */
+static int
+mfs_count_free_bits(struct mfs_instance *inst, bmap_id_t bid, uint32_t *free)
+{
+        int r;
+        unsigned start_block;
+        unsigned long nblocks;
+        unsigned long nbits;
+        unsigned long block;
+        unsigned long free_bits = 0;
+        bitchunk_t chunk;
+        size_t const bitchunk_bits = sizeof(bitchunk_t) * 8;
+        block_t *b;
+        struct mfs_sb_info *sbi = inst->sbi;
+
+        start_block = MFS_BMAP_START_BLOCK(sbi, bid);
+        nblocks = MFS_BMAP_SIZE_BLOCKS(sbi, bid);
+        nbits = MFS_BMAP_SIZE_BITS(sbi, bid);
+
+        for (block = 0; block < nblocks; ++block) {
+                r = block_get(&b, inst->service_id, block + start_block,
+                    BLOCK_FLAGS_NONE);
+                if (r != EOK)
+                        return r;
+
+                size_t i;
+                bitchunk_t *data = (bitchunk_t *) b->data;
+
+                /* Read the bitmap block, chunk per chunk,
+                 * counting the zero bits.
+                 */
+                for (i = 0; i < sbi->block_size / sizeof(bitchunk_t); ++i) {
+                        chunk = conv32(sbi->native, data[i]);
+
+                        size_t bit;
+                        for (bit = 0; bit < bitchunk_bits && nbits > 0;
+                            ++bit, --nbits) {
+                                if (!(chunk & (1 << bit)))
+                                        free_bits++;
+                        }
+
+                        if (nbits == 0)
+                                break;
+                }
+
+                r = block_put(b);
+                if (r != EOK)
+                        return r;
+        }
+
+        *free = free_bits;
+        assert(nbits == 0);
+
+        return EOK;
 }
 
@@ -124 +221 @@
         sbi = inst->sbi;
 
+        start_block = MFS_BMAP_START_BLOCK(sbi, bid);
+
         if (bid == BMAP_ZONE) {
                 search = &sbi->zsearch;
-                start_block = 2 + sbi->ibmap_blocks;
                 if (idx > sbi->nzones) {
                         printf(NAME ": Error! Trying to free beyond the "
@@ -135 +233 @@
                 /* bid == BMAP_INODE */
                 search = &sbi->isearch;
-                start_block = 2;
                 if (idx > sbi->ninodes) {
                         printf(NAME ": Error! Trying to free beyond the "
@@ -192 +289 @@
         sbi = inst->sbi;
 
+        start_block = MFS_BMAP_START_BLOCK(sbi, bid);
+        limit = MFS_BMAP_SIZE_BITS(sbi, bid);
+        nblocks = MFS_BMAP_SIZE_BLOCKS(sbi, bid);
+
         if (bid == BMAP_ZONE) {
                 search = &sbi->zsearch;
-                start_block = 2 + sbi->ibmap_blocks;
-                nblocks = sbi->zbmap_blocks;
-                limit = sbi->nzones - sbi->firstdatazone - 1;
         } else {
                 /* bid == BMAP_INODE */
                 search = &sbi->isearch;
-                start_block = 2;
-                nblocks = sbi->ibmap_blocks;
-                limit = sbi->ninodes - 1;
         }
         bits_per_block = sbi->block_size * 8;