Changeset d0d7afb in mainline for uspace/lib/ext4/libext4_directory.c

Timestamp:

2012-03-01T19:56:31Z (12 years ago)

Author:

Frantisek Princ <frantisek.princ@…>

Branches:

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

Children:

c30a015

Parents:

d8269dc

Message:

Code refactorization (entry insertion)

File:

• uspace/lib/ext4/libext4_directory.c (modified) (5 diffs)

uspace/lib/ext4/libext4_directory.c

@@ -314 +314 @@
 
 int ext4_directory_add_entry(ext4_filesystem_t *fs, ext4_inode_ref_t * parent,
-                const char *entry_name, ext4_inode_ref_t *child)
+                const char *name, ext4_inode_ref_t *child)
 {
         int rc;
 
-        EXT4FS_DBG("adding entry to directory \%u [ino = \%u, name = \%s]", parent->index, child->index, entry_name);
-
-        uint16_t name_len = strlen(entry_name);
+        EXT4FS_DBG("adding entry to directory \%u [ino = \%u, name = \%s]", parent->index, child->index, name);
 
         // Index adding (if allowed)
@@ -326 +324 @@
                         ext4_inode_has_flag(parent->inode, EXT4_INODE_FLAG_INDEX)) {
 
-                rc = ext4_directory_dx_add_entry(fs, parent, child, name_len, entry_name);
+                rc = ext4_directory_dx_add_entry(fs, parent, child, name);
 
                 // Check if index is not corrupted
@@ -347 +345 @@
         // Linear algorithm
 
-        ext4_directory_iterator_t it;
-        rc = ext4_directory_iterator_init(&it, fs, parent, 0);
-        if (rc != EOK) {
-                return rc;
-        }
-
+        EXT4FS_DBG("Linear algorithm");
+
+        uint32_t iblock, fblock;
         uint32_t block_size = ext4_superblock_get_block_size(fs->superblock);
-        uint16_t required_len = 8 + name_len + (4 - name_len % 4);
-
-        while (it.current != NULL) {
-                uint32_t entry_inode = ext4_directory_entry_ll_get_inode(it.current);
-                uint16_t rec_len = ext4_directory_entry_ll_get_entry_length(it.current);
-
-                if ((entry_inode == 0) && (rec_len >= required_len)) {
-
-                        ext4_directory_write_entry(fs->superblock, it.current, rec_len,
-                                        child, entry_name, name_len);
-                        it.current_block->dirty = true;
-                        return ext4_directory_iterator_fini(&it);
-                }
-
-                if (entry_inode != 0) {
-                        uint16_t used_name_len = ext4_directory_entry_ll_get_name_length(
-                                        fs->superblock, it.current);
-
-                        uint16_t used_space = 8 + used_name_len;
-                        if ((used_name_len % 4) != 0) {
-                                used_space += 4 - (used_name_len % 4);
-                        }
-                        uint16_t free_space = rec_len - used_space;
-
-                        EXT4FS_DBG("rec_len = \%u, used_space = \%u, free space = \%u", rec_len, used_space, free_space);
-
-                        if (free_space >= required_len) {
-
-                                // Cut tail of current entry
-                                ext4_directory_entry_ll_set_entry_length(it.current, used_space);
-
-                                // SEEK manually
-                                uint32_t local_offset = (it.current_offset % block_size);
-                                local_offset += used_space;
-                                ext4_directory_entry_ll_t *new_entry = it.current_block->data + local_offset;
-
-                                // We are sure, that both entries are in the same data block
-                                // dirtyness will be set now
-
-                                ext4_directory_write_entry(fs->superblock, new_entry,
-                                                free_space, child, entry_name, name_len);
-                                it.current_block->dirty = true;
-                                return ext4_directory_iterator_fini(&it);
-                        }
-
-                }
-
-                rc = ext4_directory_iterator_next(&it);
-                if (rc != EOK) {
-                        return rc;
-                }
-        }
-
-        // Destroy iterator
-        ext4_directory_iterator_fini(&it);
+        uint32_t inode_size = ext4_inode_get_size(fs->superblock, parent->inode);
+        uint32_t total_blocks = inode_size / block_size;
+
+        uint32_t name_len = strlen(name);
+
+        bool success = false;
+        for (iblock = 0; iblock < total_blocks; ++iblock) {
+
+                rc = ext4_filesystem_get_inode_data_block_index(fs, parent->inode, iblock, &fblock);
+                if (rc != EOK) {
+                        return rc;
+                }
+
+                block_t *block;
+                rc = block_get(&block, fs->device, fblock, BLOCK_FLAGS_NONE);
+                if (rc != EOK) {
+                        return rc;
+                }
+
+                rc = ext4_directory_try_insert_entry(fs->superblock, block, child, name, name_len);
+                if (rc == EOK) {
+                        success = true;
+                }
+
+                rc = block_put(block);
+                if (rc != EOK) {
+                        return rc;
+                }
+
+                if (success) {
+                        return EOK;
+                }
+        }
+
 
         EXT4FS_DBG("NO FREE SPACE - needed to allocate block");
 
-        uint32_t fblock;
-        uint32_t iblock;
         rc = ext4_directory_append_block(fs, parent, &fblock, &iblock);
         if (rc != EOK) {
@@ -428 +400 @@
         // Fill block with zeroes
         memset(new_block->data, 0, block_size);
-
         ext4_directory_entry_ll_t *block_entry = new_block->data;
-
-        ext4_directory_write_entry(fs->superblock, block_entry, block_size, 
-        child, entry_name, name_len);
+        ext4_directory_write_entry(fs->superblock, block_entry, block_size, child, name, name_len);
 
         new_block->dirty = true;
@@ -556 +525 @@
 }
 
+int ext4_directory_try_insert_entry(ext4_superblock_t *sb,
+                block_t *target_block, ext4_inode_ref_t *child,
+                const char *name, uint32_t name_len)
+{
+        uint32_t block_size = ext4_superblock_get_block_size(sb);
+        uint16_t required_len = sizeof(ext4_fake_directory_entry_t) + name_len;
+        if ((required_len % 4) != 0) {
+                required_len += 4 - (required_len % 4);
+        }
+
+        ext4_directory_entry_ll_t *dentry = target_block->data;
+        ext4_directory_entry_ll_t *stop = target_block->data + block_size;
+
+        while (dentry < stop) {
+
+                uint32_t inode = ext4_directory_entry_ll_get_inode(dentry);
+                uint16_t rec_len = ext4_directory_entry_ll_get_entry_length(dentry);
+
+                if ((inode == 0) && (rec_len >= required_len)) {
+                        ext4_directory_write_entry(sb, dentry, rec_len, child, name, name_len);
+                        target_block->dirty = true;
+                        return EOK;
+                }
+
+                if (inode != 0) {
+                        uint16_t used_name_len =
+                                        ext4_directory_entry_ll_get_name_length(sb, dentry);
+
+                        uint16_t used_space =
+                                        sizeof(ext4_fake_directory_entry_t) + used_name_len;
+                        if ((used_name_len % 4) != 0) {
+                                used_space += 4 - (used_name_len % 4);
+                        }
+                        uint16_t free_space = rec_len - used_space;
+
+                        if (free_space >= required_len) {
+
+                                // Cut tail of current entry
+                                ext4_directory_entry_ll_set_entry_length(dentry, used_space);
+                                ext4_directory_entry_ll_t *new_entry =
+                                                (void *)dentry + used_space;
+                                ext4_directory_write_entry(sb, new_entry,
+                                                free_space, child, name, name_len);
+
+                                target_block->dirty = true;
+                                return EOK;
+                        }
+                }
+
+                dentry = (void *)dentry + rec_len;
+        }
+
+        return ENOSPC;
+}
+
 
 /**