From b21bef3bd5ef583feed45f0500a1058cbaa47136 Mon Sep 17 00:00:00 2001 From: Charles Manning Date: Thu, 9 Jul 2020 13:31:03 +1200 Subject: [PATCH] Move cache handling into its own file Signed-off-by: Charles Manning --- yaffs_cache.c | 298 ++++++++++++++++++++++++++++++++++++++++++++++++++ yaffs_cache.h | 53 +++++++++ yaffs_guts.c | 288 ++---------------------------------------------- yaffs_guts.h | 5 + 4 files changed, 367 insertions(+), 277 deletions(-) create mode 100644 yaffs_cache.c create mode 100644 yaffs_cache.h diff --git a/yaffs_cache.c b/yaffs_cache.c new file mode 100644 index 0000000..27f54e2 --- /dev/null +++ b/yaffs_cache.c @@ -0,0 +1,298 @@ +/* + * YAFFS: Yet Another Flash File System. A NAND-flash specific file system. + * + * Copyright (C) 2002-2018 Aleph One Ltd. + * + * Created by Charles Manning + * + * 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 "yaffs_cache.h" + +/*------------------------ Short Operations Cache ------------------------------ + * In many situations where there is no high level buffering a lot of + * reads might be short sequential reads, and a lot of writes may be short + * sequential writes. eg. scanning/writing a jpeg file. + * In these cases, a short read/write cache can provide a huge perfomance + * benefit with dumb-as-a-rock code. + * In Linux, the page cache provides read buffering and the short op cache + * provides write buffering. + * + * There are a small number (~10) of cache chunks per device so that we don't + * need a very intelligent search. + */ + +int yaffs_obj_cache_dirty(struct yaffs_obj *obj) +{ + struct yaffs_dev *dev = obj->my_dev; + int i; + struct yaffs_cache *cache; + int n_caches = obj->my_dev->param.n_caches; + + for (i = 0; i < n_caches; i++) { + cache = &dev->cache[i]; + if (cache->object == obj && cache->dirty) + return 1; + } + + return 0; +} + +void yaffs_flush_single_cache(struct yaffs_cache *cache, int discard) +{ + + if (!cache || cache->locked) + return; + + /* Write it out and free it up if need be.*/ + if (cache->dirty) { + yaffs_wr_data_obj(cache->object, + cache->chunk_id, + cache->data, + cache->n_bytes, + 1); + + cache->dirty = 0; + } + + if (discard) + cache->object = NULL; +} + +void yaffs_flush_file_cache(struct yaffs_obj *obj, int discard) +{ + struct yaffs_dev *dev = obj->my_dev; + int i; + struct yaffs_cache *cache; + int n_caches = obj->my_dev->param.n_caches; + + if (n_caches < 1) + return; + + + /* Find the chunks for this object and flush them. */ + for (i = 0; i < n_caches; i++) { + cache = &dev->cache[i]; + if (cache->object == obj) + yaffs_flush_single_cache(cache, discard); + } + +} + + +void yaffs_flush_whole_cache(struct yaffs_dev *dev, int discard) +{ + struct yaffs_obj *obj; + int n_caches = dev->param.n_caches; + int i; + + /* Find a dirty object in the cache and flush it... + * until there are no further dirty objects. + */ + do { + obj = NULL; + for (i = 0; i < n_caches && !obj; i++) { + if (dev->cache[i].object && dev->cache[i].dirty) + obj = dev->cache[i].object; + } + if (obj) + yaffs_flush_file_cache(obj, discard); + } while (obj); + +} + +/* Grab us an unused cache chunk for use. + * First look for an empty one. + * Then look for the least recently used non-dirty one. + * Then look for the least recently used dirty one...., flush and look again. + */ +static struct yaffs_cache *yaffs_grab_chunk_worker(struct yaffs_dev *dev) +{ + u32 i; + + if (dev->param.n_caches > 0) { + for (i = 0; i < dev->param.n_caches; i++) { + if (!dev->cache[i].object) + return &dev->cache[i]; + } + } + + return NULL; +} + +struct yaffs_cache *yaffs_grab_chunk_cache(struct yaffs_dev *dev) +{ + struct yaffs_cache *cache; + int usage; + u32 i; + + if (dev->param.n_caches < 1) + return NULL; + + /* First look for an unused cache */ + + cache = yaffs_grab_chunk_worker(dev); + + if (cache) + return cache; + + /* + * Thery were all in use. + * Find the LRU cache and flush it if it is dirty. + */ + + usage = -1; + cache = NULL; + + for (i = 0; i < dev->param.n_caches; i++) { + if (dev->cache[i].object && + !dev->cache[i].locked && + (dev->cache[i].last_use < usage || !cache)) { + usage = dev->cache[i].last_use; + cache = &dev->cache[i]; + } + } + +#if 1 + yaffs_flush_single_cache(cache, 1); +#else + yaffs_flush_file_cache(cache->object, 1); + cache = yaffs_grab_chunk_worker(dev); +#endif + + return cache; +} + +/* Find a cached chunk */ +struct yaffs_cache *yaffs_find_chunk_cache(const struct yaffs_obj *obj, + int chunk_id) +{ + struct yaffs_dev *dev = obj->my_dev; + u32 i; + + if (dev->param.n_caches < 1) + return NULL; + + for (i = 0; i < dev->param.n_caches; i++) { + if (dev->cache[i].object == obj && + dev->cache[i].chunk_id == chunk_id) { + dev->cache_hits++; + + return &dev->cache[i]; + } + } + return NULL; +} + +/* Mark the chunk for the least recently used algorithym */ +void yaffs_use_cache(struct yaffs_dev *dev, struct yaffs_cache *cache, + int is_write) +{ + u32 i; + + if (dev->param.n_caches < 1) + return; + + if (dev->cache_last_use < 0 || + dev->cache_last_use > 100000000) { + /* Reset the cache usages */ + for (i = 1; i < dev->param.n_caches; i++) + dev->cache[i].last_use = 0; + + dev->cache_last_use = 0; + } + dev->cache_last_use++; + cache->last_use = dev->cache_last_use; + + if (is_write) + cache->dirty = 1; +} + +/* Invalidate a single cache page. + * Do this when a whole page gets written, + * ie the short cache for this page is no longer valid. + */ +void yaffs_invalidate_chunk_cache(struct yaffs_obj *object, int chunk_id) +{ + struct yaffs_cache *cache; + + if (object->my_dev->param.n_caches > 0) { + cache = yaffs_find_chunk_cache(object, chunk_id); + + if (cache) + cache->object = NULL; + } +} + +/* Invalidate all the cache pages associated with this object + * Do this whenever ther file is deleted or resized. + */ +void yaffs_invalidate_file_cache(struct yaffs_obj *in) +{ + u32 i; + struct yaffs_dev *dev = in->my_dev; + + if (dev->param.n_caches > 0) { + /* Invalidate it. */ + for (i = 0; i < dev->param.n_caches; i++) { + if (dev->cache[i].object == in) + dev->cache[i].object = NULL; + } + } +} + + +int yaffs_cache_init(struct yaffs_dev *dev) +{ + int init_failed; + + if (dev->param.n_caches > 0) { + u32 i; + void *buf; + u32 cache_bytes = + dev->param.n_caches * sizeof(struct yaffs_cache); + + if (dev->param.n_caches > YAFFS_MAX_SHORT_OP_CACHES) + dev->param.n_caches = YAFFS_MAX_SHORT_OP_CACHES; + + dev->cache = kmalloc(cache_bytes, GFP_NOFS); + + buf = (u8 *) dev->cache; + + if (dev->cache) + memset(dev->cache, 0, cache_bytes); + + for (i = 0; i < dev->param.n_caches && buf; i++) { + dev->cache[i].object = NULL; + dev->cache[i].last_use = 0; + dev->cache[i].dirty = 0; + dev->cache[i].data = buf = + kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS); + } + if (!buf) + init_failed = 1; + + dev->cache_last_use = 0; + } + + return init_failed ? -1 : 0; +} + +void yaffs_cache_deinit(struct yaffs_dev *dev) +{ + + if (dev->param.n_caches > 0 && dev->cache) { + u32 i; + + for (i = 0; i < dev->param.n_caches; i++) { + kfree(dev->cache[i].data); + dev->cache[i].data = NULL; + } + + kfree(dev->cache); + dev->cache = NULL; + } +} diff --git a/yaffs_cache.h b/yaffs_cache.h new file mode 100644 index 0000000..1dcd7e7 --- /dev/null +++ b/yaffs_cache.h @@ -0,0 +1,53 @@ +/* + * YAFFS: Yet Another Flash File System. A NAND-flash specific file system. + * + * Copyright (C) 2002-2018 Aleph One Ltd. + * + * Created by Charles Manning + * + * 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. + */ + +#ifndef __YAFFS_CACHE_H__ +#define __YAFFS_CACHE_H__ + +#include "yaffs_guts.h" + + +/* Does the object have a dirty cache ? */ +int yaffs_obj_cache_dirty(struct yaffs_obj *obj); + +/* Flush the cache associated with a file, either discarding or keeping */ +void yaffs_flush_file_cache(struct yaffs_obj *obj, int discard); + +/* Flush everything in the cache, either discarding or keeping */ +void yaffs_flush_whole_cache(struct yaffs_dev *dev, int discard); + +/* Grab a cache item during read or write. */ +struct yaffs_cache *yaffs_grab_chunk_cache(struct yaffs_dev *dev); + +/* Find a cached chunk */ +struct yaffs_cache *yaffs_find_chunk_cache(const struct yaffs_obj *obj, + int chunk_id); + +/* Mark the chunk for the least recently used algorithym */ +void yaffs_use_cache(struct yaffs_dev *dev, struct yaffs_cache *cache, + int is_write); + + +/* Invalidate a single cache page. The cache no longer holds valid data. */ +void yaffs_invalidate_chunk_cache(struct yaffs_obj *object, + int chunk_id); + +/* Invalidate all the cache pages associated with this object + * Do this whenever ther file is deleted or resized. + */ +void yaffs_invalidate_file_cache(struct yaffs_obj *in); + +/* Init/deinit. */ +int yaffs_cache_init(struct yaffs_dev *dev); +void yaffs_cache_deinit(struct yaffs_dev *dev); + +#endif diff --git a/yaffs_guts.c b/yaffs_guts.c index c52ff84..3023011 100644 --- a/yaffs_guts.c +++ b/yaffs_guts.c @@ -14,6 +14,8 @@ #include "yaffs_trace.h" #include "yaffs_guts.h" + +#include "yaffs_cache.h" #include "yaffs_endian.h" #include "yaffs_getblockinfo.h" #include "yaffs_tagscompat.h" @@ -38,9 +40,6 @@ /* Forward declarations */ -static int yaffs_wr_data_obj(struct yaffs_obj *in, int inode_chunk, - const u8 *buffer, int n_bytes, int use_reserve); - static void yaffs_fix_null_name(struct yaffs_obj *obj, YCHAR *name, int buffer_size); @@ -1422,237 +1421,6 @@ static int yaffs_change_obj_name(struct yaffs_obj *obj, return YAFFS_FAIL; } -/*------------------------ Short Operations Cache ------------------------------ - * In many situations where there is no high level buffering a lot of - * reads might be short sequential reads, and a lot of writes may be short - * sequential writes. eg. scanning/writing a jpeg file. - * In these cases, a short read/write cache can provide a huge perfomance - * benefit with dumb-as-a-rock code. - * In Linux, the page cache provides read buffering and the short op cache - * provides write buffering. - * - * There are a small number (~10) of cache chunks per device so that we don't - * need a very intelligent search. - */ - -static int yaffs_obj_cache_dirty(struct yaffs_obj *obj) -{ - struct yaffs_dev *dev = obj->my_dev; - int i; - struct yaffs_cache *cache; - int n_caches = obj->my_dev->param.n_caches; - - for (i = 0; i < n_caches; i++) { - cache = &dev->cache[i]; - if (cache->object == obj && cache->dirty) - return 1; - } - - return 0; -} - -static void yaffs_flush_single_cache(struct yaffs_cache *cache, int discard) -{ - - if (!cache || cache->locked) - return; - - /* Write it out and free it up if need be.*/ - if (cache->dirty) { - yaffs_wr_data_obj(cache->object, - cache->chunk_id, - cache->data, - cache->n_bytes, - 1); - - cache->dirty = 0; - } - - if (discard) - cache->object = NULL; -} - -static void yaffs_flush_file_cache(struct yaffs_obj *obj, int discard) -{ - struct yaffs_dev *dev = obj->my_dev; - int i; - struct yaffs_cache *cache; - int n_caches = obj->my_dev->param.n_caches; - - if (n_caches < 1) - return; - - - /* Find the chunks for this object and flush them. */ - for (i = 0; i < n_caches; i++) { - cache = &dev->cache[i]; - if (cache->object == obj) - yaffs_flush_single_cache(cache, discard); - } - -} - - -void yaffs_flush_whole_cache(struct yaffs_dev *dev, int discard) -{ - struct yaffs_obj *obj; - int n_caches = dev->param.n_caches; - int i; - - /* Find a dirty object in the cache and flush it... - * until there are no further dirty objects. - */ - do { - obj = NULL; - for (i = 0; i < n_caches && !obj; i++) { - if (dev->cache[i].object && dev->cache[i].dirty) - obj = dev->cache[i].object; - } - if (obj) - yaffs_flush_file_cache(obj, discard); - } while (obj); - -} - -/* Grab us an unused cache chunk for use. - * First look for an empty one. - * Then look for the least recently used non-dirty one. - * Then look for the least recently used dirty one...., flush and look again. - */ -static struct yaffs_cache *yaffs_grab_chunk_worker(struct yaffs_dev *dev) -{ - u32 i; - - if (dev->param.n_caches > 0) { - for (i = 0; i < dev->param.n_caches; i++) { - if (!dev->cache[i].object) - return &dev->cache[i]; - } - } - - return NULL; -} - -static struct yaffs_cache *yaffs_grab_chunk_cache(struct yaffs_dev *dev) -{ - struct yaffs_cache *cache; - int usage; - u32 i; - - if (dev->param.n_caches < 1) - return NULL; - - /* First look for an unused cache */ - - cache = yaffs_grab_chunk_worker(dev); - - if (cache) - return cache; - - /* - * Thery were all in use. - * Find the LRU cache and flush it if it is dirty. - */ - - usage = -1; - cache = NULL; - - for (i = 0; i < dev->param.n_caches; i++) { - if (dev->cache[i].object && - !dev->cache[i].locked && - (dev->cache[i].last_use < usage || !cache)) { - usage = dev->cache[i].last_use; - cache = &dev->cache[i]; - } - } - -#if 1 - yaffs_flush_single_cache(cache, 1); -#else - yaffs_flush_file_cache(cache->object, 1); - cache = yaffs_grab_chunk_worker(dev); -#endif - - return cache; -} - -/* Find a cached chunk */ -static struct yaffs_cache *yaffs_find_chunk_cache(const struct yaffs_obj *obj, - int chunk_id) -{ - struct yaffs_dev *dev = obj->my_dev; - u32 i; - - if (dev->param.n_caches < 1) - return NULL; - - for (i = 0; i < dev->param.n_caches; i++) { - if (dev->cache[i].object == obj && - dev->cache[i].chunk_id == chunk_id) { - dev->cache_hits++; - - return &dev->cache[i]; - } - } - return NULL; -} - -/* Mark the chunk for the least recently used algorithym */ -static void yaffs_use_cache(struct yaffs_dev *dev, struct yaffs_cache *cache, - int is_write) -{ - u32 i; - - if (dev->param.n_caches < 1) - return; - - if (dev->cache_last_use < 0 || - dev->cache_last_use > 100000000) { - /* Reset the cache usages */ - for (i = 1; i < dev->param.n_caches; i++) - dev->cache[i].last_use = 0; - - dev->cache_last_use = 0; - } - dev->cache_last_use++; - cache->last_use = dev->cache_last_use; - - if (is_write) - cache->dirty = 1; -} - -/* Invalidate a single cache page. - * Do this when a whole page gets written, - * ie the short cache for this page is no longer valid. - */ -static void yaffs_invalidate_chunk_cache(struct yaffs_obj *object, int chunk_id) -{ - struct yaffs_cache *cache; - - if (object->my_dev->param.n_caches > 0) { - cache = yaffs_find_chunk_cache(object, chunk_id); - - if (cache) - cache->object = NULL; - } -} - -/* Invalidate all the cache pages associated with this object - * Do this whenever ther file is deleted or resized. - */ -static void yaffs_invalidate_whole_cache(struct yaffs_obj *in) -{ - u32 i; - struct yaffs_dev *dev = in->my_dev; - - if (dev->param.n_caches > 0) { - /* Invalidate it. */ - for (i = 0; i < dev->param.n_caches; i++) { - if (dev->cache[i].object == in) - dev->cache[i].object = NULL; - } - } -} static void yaffs_unhash_obj(struct yaffs_obj *obj) { @@ -1708,7 +1476,7 @@ void yaffs_handle_defered_free(struct yaffs_obj *obj) static int yaffs_generic_obj_del(struct yaffs_obj *in) { /* Iinvalidate the file's data in the cache, without flushing. */ - yaffs_invalidate_whole_cache(in); + yaffs_invalidate_file_cache(in); if (in->my_dev->param.is_yaffs2 && in->parent != in->my_dev->del_dir) { /* Move to unlinked directory so we have a deletion record */ @@ -2701,7 +2469,7 @@ static unsigned yaffs_find_gc_block(struct yaffs_dev *dev, int prioritised = 0; int prioritised_exist = 0; struct yaffs_block_info *bi; - u32 threshold; + u32 threshold = dev->param.chunks_per_block; /* First let's see if we need to grab a prioritised block */ if (dev->has_pending_prioritised_gc && !aggressive) { @@ -3041,8 +2809,8 @@ void yaffs_chunk_del(struct yaffs_dev *dev, int chunk_id, int mark_flash, } } -static int yaffs_wr_data_obj(struct yaffs_obj *in, int inode_chunk, - const u8 *buffer, int n_bytes, int use_reserve) +int yaffs_wr_data_obj(struct yaffs_obj *in, int inode_chunk, + const u8 *buffer, int n_bytes, int use_reserve) { /* Find old chunk Need to do this to get serial number * Write new one and patch into tree. @@ -3791,7 +3559,7 @@ int yaffs_resize_file(struct yaffs_obj *in, loff_t new_size) loff_t old_size = in->variant.file_variant.file_size; yaffs_flush_file_cache(in, 1); - yaffs_invalidate_whole_cache(in); + yaffs_invalidate_file_cache(in); yaffs_check_gc(dev, 0); @@ -4924,37 +4692,13 @@ int yaffs_guts_initialise(struct yaffs_dev *dev) if (!yaffs_init_tmp_buffers(dev)) init_failed = 1; - dev->cache = NULL; dev->gc_cleanup_list = NULL; - if (!init_failed && dev->param.n_caches > 0) { - u32 i; - void *buf; - u32 cache_bytes = - dev->param.n_caches * sizeof(struct yaffs_cache); - - if (dev->param.n_caches > YAFFS_MAX_SHORT_OP_CACHES) - dev->param.n_caches = YAFFS_MAX_SHORT_OP_CACHES; - dev->cache = kmalloc(cache_bytes, GFP_NOFS); - - buf = (u8 *) dev->cache; - - if (dev->cache) - memset(dev->cache, 0, cache_bytes); - - for (i = 0; i < dev->param.n_caches && buf; i++) { - dev->cache[i].object = NULL; - dev->cache[i].last_use = 0; - dev->cache[i].dirty = 0; - dev->cache[i].data = buf = - kmalloc(dev->param.total_bytes_per_chunk, GFP_NOFS); - } - if (!buf) - init_failed = 1; + dev->cache = NULL; - dev->cache_last_use = 0; - } + if (!init_failed) + init_failed = yaffs_cache_init(dev) < 0; dev->cache_hits = 0; @@ -5065,17 +4809,7 @@ void yaffs_deinitialise(struct yaffs_dev *dev) yaffs_deinit_blocks(dev); yaffs_deinit_tnodes_and_objs(dev); yaffs_summary_deinit(dev); - - if (dev->param.n_caches > 0 && dev->cache) { - - for (i = 0; i < dev->param.n_caches; i++) { - kfree(dev->cache[i].data); - dev->cache[i].data = NULL; - } - - kfree(dev->cache); - dev->cache = NULL; - } + yaffs_cache_deinit(dev); kfree(dev->gc_cleanup_list); diff --git a/yaffs_guts.h b/yaffs_guts.h index 124e4c9..5fa1877 100644 --- a/yaffs_guts.h +++ b/yaffs_guts.h @@ -1040,6 +1040,11 @@ loff_t yaffs_oh_to_size(struct yaffs_dev *dev, struct yaffs_obj_hdr *oh, int do_endian); loff_t yaffs_max_file_size(struct yaffs_dev *dev); + +/* yaffs_wr_data_obj needs to be exposed to allow the cache to access it. */ +int yaffs_wr_data_obj(struct yaffs_obj *in, int inode_chunk, + const u8 *buffer, int n_bytes, int use_reserve); + /* * Debug function to count number of blocks in each state * NB Needs to be called with correct number of integers -- 2.30.2