1B200的rt-thread示例工程

/* * YAFFS: Yet Another Flash File System. A NAND-flash specific file system. * * Copyright (C) 2002-2011 Aleph One Ltd. * for Toby Churchill Ltd and Brightstar Engineering * * Created by Charles Manning <charles@aleph1.co.uk> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <stdio.h> #include "direct/yportenv.h" #include "yaffs_trace.h" #include "yaffs_guts.h" #include "yaffs_getblockinfo.h" #include "yaffs_tagscompat.h" #include "yaffs_nand.h" #include "yaffs_yaffs1.h" #include "yaffs_yaffs2.h" #include "yaffs_bitmap.h" #include "yaffs_verify.h" #include "yaffs_nand.h" #include "yaffs_packedtags2.h" #include "yaffs_nameval.h" #include "yaffs_allocator.h" #include "yaffs_attribs.h" #include "yaffs_summary.h" /* Note YAFFS_GC_GOOD_ENOUGH must be <= YAFFS_GC_PASSIVE_THRESHOLD */ #define YAFFS_GC_GOOD_ENOUGH 2 #define YAFFS_GC_PASSIVE_THRESHOLD 4 #include "yaffs_ecc.h" /* Forward declarations */ static int yaffs_wr_data_obj(struct yaffs_obj *in, int inode_chunk, const u8 *buffer, int n_bytes, int use_reserve); /* Function to calculate chunk and offset */ static inline void yaffs_addr_to_chunk(struct yaffs_dev *dev, loff_t addr, int *chunk_out, u32 *offset_out) { int chunk; u32 offset; chunk = (u32) (addr >> dev->chunk_shift); if (dev->chunk_div == 1) { /* easy power of 2 case */ offset = (u32) (addr & dev->chunk_mask); } else { /* Non power-of-2 case */ loff_t chunk_base; chunk /= dev->chunk_div; chunk_base = ((loff_t) chunk) * dev->data_bytes_per_chunk; offset = (u32) (addr - chunk_base); } *chunk_out = chunk; *offset_out = offset; } /* Function to return the number of shifts for a power of 2 greater than or * equal to the given number * Note we don't try to cater for all possible numbers and this does not have to * be hellishly efficient. */ static inline u32 calc_shifts_ceiling(u32 x) { int extra_bits; int shifts; shifts = extra_bits = 0; while (x > 1) { if (x & 1) extra_bits++; x >>= 1; shifts++; } if (extra_bits) shifts++; return shifts; } /* Function to return the number of shifts to get a 1 in bit 0 */ static inline u32 calc_shifts(u32 x) { u32 shifts; shifts = 0; if (!x) return 0; while (!(x & 1)) { x >>= 1; shifts++; } return shifts; } /* * Temporary buffer manipulations. */ static int yaffs_init_tmp_buffers(struct yaffs_dev *dev) { int i; u8 *buf = (u8 *) 1; memset(dev->temp_buffer, 0, sizeof(dev->temp_buffer)); for (i = 0; buf && i < YAFFS_N_TEMP_BUFFERS; i++) { dev->temp_buffer[i].in_use = 0; buf = kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS); dev->temp_buffer[i].buffer = buf; } return buf ? YAFFS_OK : YAFFS_FAIL; } u8 *yaffs_get_temp_buffer(struct yaffs_dev * dev) { int i; dev->temp_in_use++; if (dev->temp_in_use > dev->max_temp) dev->max_temp = dev->temp_in_use; for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) { if (dev->temp_buffer[i].in_use == 0) { dev->temp_buffer[i].in_use = 1; return dev->temp_buffer[i].buffer; } } yaffs_trace(YAFFS_TRACE_BUFFERS, "Out of temp buffers"); /* * If we got here then we have to allocate an unmanaged one * This is not good. */ dev->unmanaged_buffer_allocs++; return kmalloc(dev->data_bytes_per_chunk, GFP_NOFS); } void yaffs_release_temp_buffer(struct yaffs_dev *dev, u8 *buffer) { int i; dev->temp_in_use--; for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) { if (dev->temp_buffer[i].buffer == buffer) { dev->temp_buffer[i].in_use = 0; return; } } if (buffer) { /* assume it is an unmanaged one. */ yaffs_trace(YAFFS_TRACE_BUFFERS, "Releasing unmanaged temp buffer"); kfree(buffer); dev->unmanaged_buffer_deallocs++; } } /* * Determine if we have a managed buffer. */ int yaffs_is_managed_tmp_buffer(struct yaffs_dev *dev, const u8 *buffer) { int i; for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) { if (dev->temp_buffer[i].buffer == buffer) return 1; } for (i = 0; i < dev->param.n_caches; i++) { if (dev->cache[i].data == buffer) return 1; } if (buffer == dev->checkpt_buffer) return 1; yaffs_trace(YAFFS_TRACE_ALWAYS, "yaffs: unmaged buffer detected."); return 0; } /* * Functions for robustisizing TODO * */ static void yaffs_handle_chunk_wr_ok(struct yaffs_dev *dev, int nand_chunk, const u8 *data, const struct yaffs_ext_tags *tags) { /* dev = dev; nand_chunk = nand_chunk; data = data; tags = tags; */ } static void yaffs_handle_chunk_update(struct yaffs_dev *dev, int nand_chunk, const struct yaffs_ext_tags *tags) { /* dev = dev; nand_chunk = nand_chunk; tags = tags; */ } void yaffs_handle_chunk_error(struct yaffs_dev *dev, struct yaffs_block_info *bi) { if (!bi->gc_prioritise) { bi->gc_prioritise = 1; dev->has_pending_prioritised_gc = 1; bi->chunk_error_strikes++; if (bi->chunk_error_strikes > 3) { bi->needs_retiring = 1; /* Too many stikes, so retire */ yaffs_trace(YAFFS_TRACE_ALWAYS, "yaffs: Block struck out"); } } } static void yaffs_handle_chunk_wr_error(struct yaffs_dev *dev, int nand_chunk, int erased_ok) { int flash_block = nand_chunk / dev->param.chunks_per_block; struct yaffs_block_info *bi = yaffs_get_block_info(dev, flash_block); yaffs_handle_chunk_error(dev, bi); if (erased_ok) { /* Was an actual write failure, * so mark the block for retirement.*/ bi->needs_retiring = 1; yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS, "**>> Block %d needs retiring", flash_block); } /* Delete the chunk */ yaffs_chunk_del(dev, nand_chunk, 1, __LINE__); yaffs_skip_rest_of_block(dev); } /* * Verification code */ /* * Simple hash function. Needs to have a reasonable spread */ static inline int yaffs_hash_fn(int n) { n = abs(n); return n % YAFFS_NOBJECT_BUCKETS; } /* * Access functions to useful fake objects. * Note that root might have a presence in NAND if permissions are set. */ struct yaffs_obj *yaffs_root(struct yaffs_dev *dev) { return dev->root_dir; } struct yaffs_obj *yaffs_lost_n_found(struct yaffs_dev *dev) { return dev->lost_n_found; } /* * Erased NAND checking functions */ int yaffs_check_ff(u8 *buffer, int n_bytes) { /* Horrible, slow implementation */ while (n_bytes--) { if (*buffer != 0xff) return 0; buffer++; } return 1; } static int yaffs_check_chunk_erased(struct yaffs_dev *dev, int nand_chunk) { int retval = YAFFS_OK; u8 *data = yaffs_get_temp_buffer(dev); struct yaffs_ext_tags tags; int result; result = yaffs_rd_chunk_tags_nand(dev, nand_chunk, data, &tags); if (tags.ecc_result > YAFFS_ECC_RESULT_NO_ERROR) retval = YAFFS_FAIL; if (!yaffs_check_ff(data, dev->data_bytes_per_chunk) || tags.chunk_used) { yaffs_trace(YAFFS_TRACE_NANDACCESS, "Chunk %d not erased", nand_chunk); retval = YAFFS_FAIL; } yaffs_release_temp_buffer(dev, data); return retval; } static int yaffs_verify_chunk_written(struct yaffs_dev *dev, int nand_chunk, const u8 *data, struct yaffs_ext_tags *tags) { int retval = YAFFS_OK; struct yaffs_ext_tags temp_tags; u8 *buffer = yaffs_get_temp_buffer(dev); int result; result = yaffs_rd_chunk_tags_nand(dev, nand_chunk, buffer, &temp_tags); if (memcmp(buffer, data, dev->data_bytes_per_chunk) || temp_tags.obj_id != tags->obj_id || temp_tags.chunk_id != tags->chunk_id || temp_tags.n_bytes != tags->n_bytes) retval = YAFFS_FAIL; yaffs_release_temp_buffer(dev, buffer); return retval; } int yaffs_check_alloc_available(struct yaffs_dev *dev, int n_chunks) { int reserved_chunks; int reserved_blocks = dev->param.n_reserved_blocks; int checkpt_blocks; checkpt_blocks = yaffs_calc_checkpt_blocks_required(dev); reserved_chunks = (reserved_blocks + checkpt_blocks) * dev->param.chunks_per_block; return (dev->n