fsw_status_t fsw_dnode_stat(struct fsw_dnode *dno, struct fsw_dnode_stat *sb) { fsw_status_t status; status = fsw_dnode_fill(dno); if (status) return status; sb->used_bytes = 0; status = dno->vol->fstype_table->dnode_stat(dno->vol, dno, sb); if (!status && !sb->used_bytes) sb->used_bytes = FSW_U64_DIV(dno->size + dno->vol->log_blocksize - 1, dno->vol->log_blocksize); return status; }
fsw_status_t fsw_shandle_read(struct fsw_shandle *shand, fsw_u32 *buffer_size_inout, void *buffer_in) { fsw_status_t status; struct fsw_dnode *dno = shand->dnode; struct fsw_volume *vol = dno->vol; fsw_u8 *buffer, *block_buffer; fsw_u64 buflen, copylen, pos; fsw_u64 log_bno, pos_in_extent, phys_bno, pos_in_physblock; fsw_u32 cache_level; if (shand->pos >= dno->size) { // already at EOF *buffer_size_inout = 0; return FSW_SUCCESS; } // initialize vars buffer = buffer_in; buflen = *buffer_size_inout; pos = (fsw_u32)shand->pos; cache_level = (dno->type != FSW_DNODE_TYPE_FILE) ? 1 : 0; // restrict read to file size if (buflen > dno->size - pos) buflen = (fsw_u32)(dno->size - pos); while (buflen > 0) { // get extent for the current logical block log_bno = FSW_U64_DIV(pos, vol->log_blocksize); if (shand->extent.type == FSW_EXTENT_TYPE_INVALID || log_bno < shand->extent.log_start || log_bno >= shand->extent.log_start + shand->extent.log_count) { if (shand->extent.type == FSW_EXTENT_TYPE_BUFFER) fsw_free(shand->extent.buffer); // ask the file system for the proper extent shand->extent.log_start = log_bno; status = vol->fstype_table->get_extent(vol, dno, &shand->extent); if (status) { shand->extent.type = FSW_EXTENT_TYPE_INVALID; return status; } } pos_in_extent = pos - shand->extent.log_start * vol->log_blocksize; // dispatch by extent type if (shand->extent.type == FSW_EXTENT_TYPE_PHYSBLOCK) { // convert to physical block number and offset phys_bno = shand->extent.phys_start + FSW_U64_DIV(pos_in_extent, vol->phys_blocksize); pos_in_physblock = pos_in_extent & (vol->phys_blocksize - 1); copylen = vol->phys_blocksize - pos_in_physblock; if (copylen > buflen) copylen = buflen; // get one physical block status = fsw_block_get(vol, phys_bno, cache_level, (void **)&block_buffer); if (status) return status; // copy data from it fsw_memcpy(buffer, block_buffer + pos_in_physblock, copylen); fsw_block_release(vol, phys_bno, block_buffer); } else if (shand->extent.type == FSW_EXTENT_TYPE_BUFFER) { copylen = shand->extent.log_count * vol->log_blocksize - pos_in_extent; if (copylen > buflen) copylen = buflen; fsw_memcpy(buffer, (fsw_u8 *)shand->extent.buffer + pos_in_extent, copylen); } else { // _SPARSE or _INVALID copylen = shand->extent.log_count * vol->log_blocksize - pos_in_extent; if (copylen > buflen) copylen = buflen; fsw_memzero(buffer, copylen); } buffer += copylen; buflen -= copylen; pos += copylen; } *buffer_size_inout = (fsw_u32)(pos - shand->pos); shand->pos = pos; return FSW_SUCCESS; }