1 files changed, 0 insertions, 163 deletions

diff --git a/works/life/operating-system-course-design/0001-crupesteam-fat-patch.patch b/works/life/operating-system-course-design/0001-crupesteam-fat-patch.patch
deleted file mode 100644
index 9f23ebb..0000000
--- a/works/life/operating-system-course-design/0001-crupesteam-fat-patch.patch
+++ /dev/null
@@ -1,163 +0,0 @@
-From e88345bbb9a4027033254933ee2e1cad9feab6d6 Mon Sep 17 00:00:00 2001
-From: crupest <crupest@outlook.com>
-Date: Thu, 24 Jun 2021 16:00:04 +0800
-Subject: [PATCH] crupesteam fat patch.
-
----
- fs/fat/cache.c | 64 ++++++++++++++++++++++++++++++++++++++++++++------
- 1 file changed, 57 insertions(+), 7 deletions(-)
-
-diff --git a/fs/fat/cache.c b/fs/fat/cache.c
-index 738e427e2d21..4f32bfee6d27 100644
---- a/fs/fat/cache.c
-+++ b/fs/fat/cache.c
-@@ -15,11 +15,15 @@
- /* this must be > 0. */
- #define FAT_MAX_CACHE	8
- 
-+#define FAT_CACHE_PREV_CLUSTER_COUNT 8
-+
- struct fat_cache {
- 	struct list_head cache_list;
- 	int nr_contig;	/* number of contiguous clusters */
- 	int fcluster;	/* cluster number in the file. */
- 	int dcluster;	/* cluster number on disk. */
-+	int prev_clusters_count;
-+	int prev_clusters[FAT_CACHE_PREV_CLUSTER_COUNT];
- };
- 
- struct fat_cache_id {
-@@ -27,6 +31,8 @@ struct fat_cache_id {
- 	int nr_contig;
- 	int fcluster;
- 	int dcluster;
-+	int prev_clusters_count;
-+	int prev_clusters[FAT_CACHE_PREV_CLUSTER_COUNT];
- };
- 
- static inline int fat_max_cache(struct inode *inode)
-@@ -84,10 +90,17 @@ static int fat_cache_lookup(struct inode *inode, int fclus,
- 	static struct fat_cache nohit = { .fcluster = 0, };
- 
- 	struct fat_cache *hit = &nohit, *p;
--	int offset = -1;
-+	int offset = INT_MIN;
- 
- 	spin_lock(&MSDOS_I(inode)->cache_lru_lock);
- 	list_for_each_entry(p, &MSDOS_I(inode)->cache_lru, cache_list) {
-+		if (p->fcluster > fclus &&
-+			p->fcluster - p->prev_clusters_count <= fclus) {
-+				hit = p;
-+				offset = fclus - hit->fcluster;
-+				break;
-+		}
-+
- 		/* Find the cache of "fclus" or nearest cache. */
- 		if (p->fcluster <= fclus && hit->fcluster < p->fcluster) {
- 			hit = p;
-@@ -107,7 +120,11 @@ static int fat_cache_lookup(struct inode *inode, int fclus,
- 		cid->fcluster = hit->fcluster;
- 		cid->dcluster = hit->dcluster;
- 		*cached_fclus = cid->fcluster + offset;
--		*cached_dclus = cid->dcluster + offset;
-+
-+		if (offset < 0)
-+			*cached_dclus = hit->prev_clusters[hit->prev_clusters_count + offset];
-+		else
-+			*cached_dclus = cid->dcluster + offset;
- 	}
- 	spin_unlock(&MSDOS_I(inode)->cache_lru_lock);
- 
-@@ -145,6 +162,8 @@ static void fat_cache_add(struct inode *inode, struct fat_cache_id *new)
- 
- 	cache = fat_cache_merge(inode, new);
- 	if (cache == NULL) {
-+		int i;
-+
- 		if (MSDOS_I(inode)->nr_caches < fat_max_cache(inode)) {
- 			MSDOS_I(inode)->nr_caches++;
- 			spin_unlock(&MSDOS_I(inode)->cache_lru_lock);
-@@ -172,6 +191,10 @@ static void fat_cache_add(struct inode *inode, struct fat_cache_id *new)
- 		cache->fcluster = new->fcluster;
- 		cache->dcluster = new->dcluster;
- 		cache->nr_contig = new->nr_contig;
-+		cache->prev_clusters_count = new->prev_clusters_count;
-+		for (i = 0; i < new->prev_clusters_count; i++) {
-+			cache->prev_clusters[i] = new->prev_clusters[i];
-+		}
- 	}
- out_update_lru:
- 	fat_cache_update_lru(inode, cache);
-@@ -220,6 +243,7 @@ static inline void cache_init(struct fat_cache_id *cid, int fclus, int dclus)
- 	cid->fcluster = fclus;
- 	cid->dcluster = dclus;
- 	cid->nr_contig = 0;
-+	cid->prev_clusters_count = 0;
- }
- 
- int fat_get_cluster(struct inode *inode, int cluster, int *fclus, int *dclus)
-@@ -230,6 +254,10 @@ int fat_get_cluster(struct inode *inode, int cluster, int *fclus, int *dclus)
- 	struct fat_entry fatent;
- 	struct fat_cache_id cid;
- 	int nr;
-+	int offset;
-+	int prev_cluster[FAT_CACHE_PREV_CLUSTER_COUNT];
-+	int prev_cluster_current = 0;
-+	int prev_cluster_count = 0;
- 
- 	BUG_ON(MSDOS_I(inode)->i_start == 0);
- 
-@@ -244,12 +272,13 @@ int fat_get_cluster(struct inode *inode, int cluster, int *fclus, int *dclus)
- 	if (cluster == 0)
- 		return 0;
- 
--	if (fat_cache_lookup(inode, cluster, &cid, fclus, dclus) < 0) {
--		/*
--		 * dummy, always not contiguous
--		 * This is reinitialized by cache_init(), later.
--		 */
-+	offset = fat_cache_lookup(inode, cluster, &cid, fclus, dclus);
-+
-+	if (offset == INT_MIN) {
- 		cache_init(&cid, -1, -1);
-+	} else if (offset < 0) {
-+		nr = 0;
-+		goto out;
- 	}
- 
- 	fatent_init(&fatent);
-@@ -278,10 +307,31 @@ int fat_get_cluster(struct inode *inode, int cluster, int *fclus, int *dclus)
- 		}
- 		(*fclus)++;
- 		*dclus = nr;
-+
-+		prev_cluster[prev_cluster_current++] = *dclus;
-+		if (prev_cluster_count < FAT_CACHE_PREV_CLUSTER_COUNT) {
-+			prev_cluster_count++;
-+		}
-+		prev_cluster_current %= FAT_CACHE_PREV_CLUSTER_COUNT;
-+
- 		if (!cache_contiguous(&cid, *dclus))
- 			cache_init(&cid, *fclus, *dclus);
- 	}
- 	nr = 0;
-+
-+	if (cid.nr_contig + 1 < FAT_CACHE_PREV_CLUSTER_COUNT) {
-+		int i;
-+		int count = prev_cluster_count - cid.nr_contig - 1;
-+		int start = ((prev_cluster_current - prev_cluster_count)
-+			+ FAT_CACHE_PREV_CLUSTER_COUNT) % FAT_CACHE_PREV_CLUSTER_COUNT; 
-+
-+		cid.prev_clusters_count = count;
-+
-+		for (i = 0; i < count; i++) {
-+			cid.prev_clusters[i] = prev_cluster[(start + i) % FAT_CACHE_PREV_CLUSTER_COUNT];
-+		}
-+	}
-+
- 	fat_cache_add(inode, &cid);
- out:
- 	fatent_brelse(&fatent);
--- 
-2.32.0
-