Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  *  linux/fs/fat/cache.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  *  Written 1992,1993 by Werner Almesberger
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7)  *  Mar 1999. AV. Changed cache, so that it uses the starting cluster instead
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8)  *	of inode number.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9)  *  May 1999. AV. Fixed the bogosity with FAT32 (read "FAT28"). Fscking lusers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10)  *  Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) #include <asm/unaligned.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) #include <linux/buffer_head.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) #include "exfat_raw.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) #include "exfat_fs.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) #define EXFAT_MAX_CACHE		16
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) struct exfat_cache {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) 	struct list_head cache_list;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) 	unsigned int nr_contig;	/* number of contiguous clusters */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) 	unsigned int fcluster;	/* cluster number in the file. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) 	unsigned int dcluster;	/* cluster number on disk. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) struct exfat_cache_id {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) 	unsigned int id;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) 	unsigned int nr_contig;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) 	unsigned int fcluster;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) 	unsigned int dcluster;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) static struct kmem_cache *exfat_cachep;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) static void exfat_cache_init_once(void *c)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) 	struct exfat_cache *cache = (struct exfat_cache *)c;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 	INIT_LIST_HEAD(&cache->cache_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) int exfat_cache_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) 	exfat_cachep = kmem_cache_create("exfat_cache",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 				sizeof(struct exfat_cache),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 				0, SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 				exfat_cache_init_once);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 	if (!exfat_cachep)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 		return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) void exfat_cache_shutdown(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 	if (!exfat_cachep)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 	kmem_cache_destroy(exfat_cachep);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) static inline struct exfat_cache *exfat_cache_alloc(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 	return kmem_cache_alloc(exfat_cachep, GFP_NOFS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) static inline void exfat_cache_free(struct exfat_cache *cache)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 	WARN_ON(!list_empty(&cache->cache_list));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 	kmem_cache_free(exfat_cachep, cache);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) static inline void exfat_cache_update_lru(struct inode *inode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 		struct exfat_cache *cache)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 	struct exfat_inode_info *ei = EXFAT_I(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 	if (ei->cache_lru.next != &cache->cache_list)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 		list_move(&cache->cache_list, &ei->cache_lru);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) static unsigned int exfat_cache_lookup(struct inode *inode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 		unsigned int fclus, struct exfat_cache_id *cid,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 		unsigned int *cached_fclus, unsigned int *cached_dclus)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 	struct exfat_inode_info *ei = EXFAT_I(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 	static struct exfat_cache nohit = { .fcluster = 0, };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 	struct exfat_cache *hit = &nohit, *p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 	unsigned int offset = EXFAT_EOF_CLUSTER;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 	spin_lock(&ei->cache_lru_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 	list_for_each_entry(p, &ei->cache_lru, cache_list) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 		/* Find the cache of "fclus" or nearest cache. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 		if (p->fcluster <= fclus && hit->fcluster < p->fcluster) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 			hit = p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 			if (hit->fcluster + hit->nr_contig < fclus) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 				offset = hit->nr_contig;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 			} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 				offset = fclus - hit->fcluster;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 				break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 			}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 	if (hit != &nohit) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 		exfat_cache_update_lru(inode, hit);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 		cid->id = ei->cache_valid_id;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 		cid->nr_contig = hit->nr_contig;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 		cid->fcluster = hit->fcluster;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 		cid->dcluster = hit->dcluster;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 		*cached_fclus = cid->fcluster + offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 		*cached_dclus = cid->dcluster + offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 	spin_unlock(&ei->cache_lru_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 	return offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) static struct exfat_cache *exfat_cache_merge(struct inode *inode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 		struct exfat_cache_id *new)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 	struct exfat_inode_info *ei = EXFAT_I(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 	struct exfat_cache *p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 	list_for_each_entry(p, &ei->cache_lru, cache_list) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 		/* Find the same part as "new" in cluster-chain. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 		if (p->fcluster == new->fcluster) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 			if (new->nr_contig > p->nr_contig)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 				p->nr_contig = new->nr_contig;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 			return p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 	return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) static void exfat_cache_add(struct inode *inode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 		struct exfat_cache_id *new)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 	struct exfat_inode_info *ei = EXFAT_I(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 	struct exfat_cache *cache, *tmp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 	if (new->fcluster == EXFAT_EOF_CLUSTER) /* dummy cache */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 	spin_lock(&ei->cache_lru_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 	if (new->id != EXFAT_CACHE_VALID &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 	    new->id != ei->cache_valid_id)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 		goto unlock;	/* this cache was invalidated */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 	cache = exfat_cache_merge(inode, new);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 	if (cache == NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 		if (ei->nr_caches < EXFAT_MAX_CACHE) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 			ei->nr_caches++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 			spin_unlock(&ei->cache_lru_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 			tmp = exfat_cache_alloc();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 			if (!tmp) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 				spin_lock(&ei->cache_lru_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 				ei->nr_caches--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 				spin_unlock(&ei->cache_lru_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 				return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 			}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 			spin_lock(&ei->cache_lru_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 			cache = exfat_cache_merge(inode, new);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 			if (cache != NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 				ei->nr_caches--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 				exfat_cache_free(tmp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 				goto out_update_lru;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 			}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 			cache = tmp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 		} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 			struct list_head *p = ei->cache_lru.prev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 			cache = list_entry(p,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 					struct exfat_cache, cache_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 		cache->fcluster = new->fcluster;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 		cache->dcluster = new->dcluster;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 		cache->nr_contig = new->nr_contig;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) out_update_lru:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 	exfat_cache_update_lru(inode, cache);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) unlock:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 	spin_unlock(&ei->cache_lru_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190)  * Cache invalidation occurs rarely, thus the LRU chain is not updated. It
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191)  * fixes itself after a while.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) static void __exfat_cache_inval_inode(struct inode *inode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) 	struct exfat_inode_info *ei = EXFAT_I(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 	struct exfat_cache *cache;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 	while (!list_empty(&ei->cache_lru)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 		cache = list_entry(ei->cache_lru.next,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 				   struct exfat_cache, cache_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 		list_del_init(&cache->cache_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 		ei->nr_caches--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 		exfat_cache_free(cache);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 	/* Update. The copy of caches before this id is discarded. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 	ei->cache_valid_id++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 	if (ei->cache_valid_id == EXFAT_CACHE_VALID)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 		ei->cache_valid_id++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) void exfat_cache_inval_inode(struct inode *inode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 	struct exfat_inode_info *ei = EXFAT_I(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 	spin_lock(&ei->cache_lru_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) 	__exfat_cache_inval_inode(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 	spin_unlock(&ei->cache_lru_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) static inline int cache_contiguous(struct exfat_cache_id *cid,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) 		unsigned int dclus)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) 	cid->nr_contig++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 	return cid->dcluster + cid->nr_contig == dclus;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) static inline void cache_init(struct exfat_cache_id *cid,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) 		unsigned int fclus, unsigned int dclus)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) 	cid->id = EXFAT_CACHE_VALID;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) 	cid->fcluster = fclus;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) 	cid->dcluster = dclus;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) 	cid->nr_contig = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) int exfat_get_cluster(struct inode *inode, unsigned int cluster,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) 		unsigned int *fclus, unsigned int *dclus,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) 		unsigned int *last_dclus, int allow_eof)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) 	struct super_block *sb = inode->i_sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) 	struct exfat_sb_info *sbi = EXFAT_SB(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) 	unsigned int limit = sbi->num_clusters;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) 	struct exfat_inode_info *ei = EXFAT_I(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) 	struct exfat_cache_id cid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) 	unsigned int content;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) 	if (ei->start_clu == EXFAT_FREE_CLUSTER) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) 		exfat_fs_error(sb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) 			"invalid access to exfat cache (entry 0x%08x)",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) 			ei->start_clu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) 		return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) 	*fclus = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) 	*dclus = ei->start_clu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) 	*last_dclus = *dclus;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) 	 * Don`t use exfat_cache if zero offset or non-cluster allocation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) 	if (cluster == 0 || *dclus == EXFAT_EOF_CLUSTER)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) 	cache_init(&cid, EXFAT_EOF_CLUSTER, EXFAT_EOF_CLUSTER);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) 	if (exfat_cache_lookup(inode, cluster, &cid, fclus, dclus) ==
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) 			EXFAT_EOF_CLUSTER) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) 		 * dummy, always not contiguous
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) 		 * This is reinitialized by cache_init(), later.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) 		WARN_ON(cid.id != EXFAT_CACHE_VALID ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) 			cid.fcluster != EXFAT_EOF_CLUSTER ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) 			cid.dcluster != EXFAT_EOF_CLUSTER ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) 			cid.nr_contig != 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) 	if (*fclus == cluster)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) 	while (*fclus < cluster) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) 		/* prevent the infinite loop of cluster chain */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) 		if (*fclus > limit) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) 			exfat_fs_error(sb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) 				"detected the cluster chain loop (i_pos %u)",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) 				(*fclus));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) 			return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) 		if (exfat_ent_get(sb, *dclus, &content))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) 			return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) 		*last_dclus = *dclus;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) 		*dclus = content;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) 		(*fclus)++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) 		if (content == EXFAT_EOF_CLUSTER) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) 			if (!allow_eof) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) 				exfat_fs_error(sb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) 				       "invalid cluster chain (i_pos %u, last_clus 0x%08x is EOF)",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) 				       *fclus, (*last_dclus));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) 				return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) 			}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) 		if (!cache_contiguous(&cid, *dclus))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) 			cache_init(&cid, *fclus, *dclus);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) 	exfat_cache_add(inode, &cid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) }