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-rw-r--r--fs/exfat/exfat_cache.c780
1 files changed, 780 insertions, 0 deletions
diff --git a/fs/exfat/exfat_cache.c b/fs/exfat/exfat_cache.c
new file mode 100644
index 000000000..e6ca88b8e
--- /dev/null
+++ b/fs/exfat/exfat_cache.c
@@ -0,0 +1,780 @@
+/*
+ * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+/************************************************************************/
+/* */
+/* PROJECT : exFAT & FAT12/16/32 File System */
+/* FILE : exfat_cache.c */
+/* PURPOSE : exFAT Cache Manager */
+/* (FAT Cache & Buffer Cache) */
+/* */
+/*----------------------------------------------------------------------*/
+/* NOTES */
+/* */
+/*----------------------------------------------------------------------*/
+/* REVISION HISTORY (Ver 0.9) */
+/* */
+/* - 2010.11.15 [Sung-Kwan Kim] : first writing */
+/* */
+/************************************************************************/
+
+#include "exfat_config.h"
+#include "exfat_data.h"
+
+#include "exfat_cache.h"
+#include "exfat_super.h"
+#include "exfat_core.h"
+
+/*----------------------------------------------------------------------*/
+/* Global Variable Definitions */
+/*----------------------------------------------------------------------*/
+
+#define sm_P(s)
+#define sm_V(s)
+
+static s32 __FAT_read(struct super_block *sb, u32 loc, u32 *content);
+static s32 __FAT_write(struct super_block *sb, u32 loc, u32 content);
+
+static BUF_CACHE_T *FAT_cache_find(struct super_block *sb, u32 sec);
+static BUF_CACHE_T *FAT_cache_get(struct super_block *sb, u32 sec);
+static void FAT_cache_insert_hash(struct super_block *sb, BUF_CACHE_T *bp);
+static void FAT_cache_remove_hash(BUF_CACHE_T *bp);
+
+static u8 *__buf_getblk(struct super_block *sb, u32 sec);
+
+static BUF_CACHE_T *buf_cache_find(struct super_block *sb, u32 sec);
+static BUF_CACHE_T *buf_cache_get(struct super_block *sb, u32 sec);
+static void buf_cache_insert_hash(struct super_block *sb, BUF_CACHE_T *bp);
+static void buf_cache_remove_hash(BUF_CACHE_T *bp);
+
+static void push_to_mru(BUF_CACHE_T *bp, BUF_CACHE_T *list);
+static void push_to_lru(BUF_CACHE_T *bp, BUF_CACHE_T *list);
+static void move_to_mru(BUF_CACHE_T *bp, BUF_CACHE_T *list);
+static void move_to_lru(BUF_CACHE_T *bp, BUF_CACHE_T *list);
+
+/*======================================================================*/
+/* Cache Initialization Functions */
+/*======================================================================*/
+
+s32 buf_init(struct super_block *sb)
+{
+ FS_INFO_T *p_fs = &(EXFAT_SB(sb)->fs_info);
+
+ int i;
+
+ /* LRU list */
+ p_fs->FAT_cache_lru_list.next = p_fs->FAT_cache_lru_list.prev = &p_fs->FAT_cache_lru_list;
+
+ for (i = 0; i < FAT_CACHE_SIZE; i++) {
+ p_fs->FAT_cache_array[i].drv = -1;
+ p_fs->FAT_cache_array[i].sec = ~0;
+ p_fs->FAT_cache_array[i].flag = 0;
+ p_fs->FAT_cache_array[i].buf_bh = NULL;
+ p_fs->FAT_cache_array[i].prev = p_fs->FAT_cache_array[i].next = NULL;
+ push_to_mru(&(p_fs->FAT_cache_array[i]), &p_fs->FAT_cache_lru_list);
+ }
+
+ p_fs->buf_cache_lru_list.next = p_fs->buf_cache_lru_list.prev = &p_fs->buf_cache_lru_list;
+
+ for (i = 0; i < BUF_CACHE_SIZE; i++) {
+ p_fs->buf_cache_array[i].drv = -1;
+ p_fs->buf_cache_array[i].sec = ~0;
+ p_fs->buf_cache_array[i].flag = 0;
+ p_fs->buf_cache_array[i].buf_bh = NULL;
+ p_fs->buf_cache_array[i].prev = p_fs->buf_cache_array[i].next = NULL;
+ push_to_mru(&(p_fs->buf_cache_array[i]), &p_fs->buf_cache_lru_list);
+ }
+
+ /* HASH list */
+ for (i = 0; i < FAT_CACHE_HASH_SIZE; i++) {
+ p_fs->FAT_cache_hash_list[i].drv = -1;
+ p_fs->FAT_cache_hash_list[i].sec = ~0;
+ p_fs->FAT_cache_hash_list[i].hash_next = p_fs->FAT_cache_hash_list[i].hash_prev = &(p_fs->FAT_cache_hash_list[i]);
+ }
+
+ for (i = 0; i < FAT_CACHE_SIZE; i++)
+ FAT_cache_insert_hash(sb, &(p_fs->FAT_cache_array[i]));
+
+ for (i = 0; i < BUF_CACHE_HASH_SIZE; i++) {
+ p_fs->buf_cache_hash_list[i].drv = -1;
+ p_fs->buf_cache_hash_list[i].sec = ~0;
+ p_fs->buf_cache_hash_list[i].hash_next = p_fs->buf_cache_hash_list[i].hash_prev = &(p_fs->buf_cache_hash_list[i]);
+ }
+
+ for (i = 0; i < BUF_CACHE_SIZE; i++)
+ buf_cache_insert_hash(sb, &(p_fs->buf_cache_array[i]));
+
+ return FFS_SUCCESS;
+} /* end of buf_init */
+
+s32 buf_shutdown(struct super_block *sb)
+{
+ return FFS_SUCCESS;
+} /* end of buf_shutdown */
+
+/*======================================================================*/
+/* FAT Read/Write Functions */
+/*======================================================================*/
+
+/* in : sb, loc
+ * out: content
+ * returns 0 on success
+ * -1 on error
+ */
+s32 FAT_read(struct super_block *sb, u32 loc, u32 *content)
+{
+ s32 ret;
+
+ sm_P(&f_sem);
+
+ ret = __FAT_read(sb, loc, content);
+
+ sm_V(&f_sem);
+
+ return ret;
+} /* end of FAT_read */
+
+s32 FAT_write(struct super_block *sb, u32 loc, u32 content)
+{
+ s32 ret;
+
+ sm_P(&f_sem);
+
+ ret = __FAT_write(sb, loc, content);
+
+ sm_V(&f_sem);
+
+ return ret;
+} /* end of FAT_write */
+
+static s32 __FAT_read(struct super_block *sb, u32 loc, u32 *content)
+{
+ s32 off;
+ u32 sec, _content;
+ u8 *fat_sector, *fat_entry;
+ FS_INFO_T *p_fs = &(EXFAT_SB(sb)->fs_info);
+ BD_INFO_T *p_bd = &(EXFAT_SB(sb)->bd_info);
+
+ if (p_fs->vol_type == FAT12) {
+ sec = p_fs->FAT1_start_sector + ((loc + (loc >> 1)) >> p_bd->sector_size_bits);
+ off = (loc + (loc >> 1)) & p_bd->sector_size_mask;
+
+ if (off == (p_bd->sector_size-1)) {
+ fat_sector = FAT_getblk(sb, sec);
+ if (!fat_sector)
+ return -1;
+
+ _content = (u32) fat_sector[off];
+
+ fat_sector = FAT_getblk(sb, ++sec);
+ if (!fat_sector)
+ return -1;
+
+ _content |= (u32) fat_sector[0] << 8;
+ } else {
+ fat_sector = FAT_getblk(sb, sec);
+ if (!fat_sector)
+ return -1;
+
+ fat_entry = &(fat_sector[off]);
+ _content = GET16(fat_entry);
+ }
+
+ if (loc & 1)
+ _content >>= 4;
+
+ _content &= 0x00000FFF;
+
+ if (_content >= CLUSTER_16(0x0FF8)) {
+ *content = CLUSTER_32(~0);
+ return 0;
+ } else {
+ *content = CLUSTER_32(_content);
+ return 0;
+ }
+ } else if (p_fs->vol_type == FAT16) {
+ sec = p_fs->FAT1_start_sector + (loc >> (p_bd->sector_size_bits-1));
+ off = (loc << 1) & p_bd->sector_size_mask;
+
+ fat_sector = FAT_getblk(sb, sec);
+ if (!fat_sector)
+ return -1;
+
+ fat_entry = &(fat_sector[off]);
+
+ _content = GET16_A(fat_entry);
+
+ _content &= 0x0000FFFF;
+
+ if (_content >= CLUSTER_16(0xFFF8)) {
+ *content = CLUSTER_32(~0);
+ return 0;
+ } else {
+ *content = CLUSTER_32(_content);
+ return 0;
+ }
+ } else if (p_fs->vol_type == FAT32) {
+ sec = p_fs->FAT1_start_sector + (loc >> (p_bd->sector_size_bits-2));
+ off = (loc << 2) & p_bd->sector_size_mask;
+
+ fat_sector = FAT_getblk(sb, sec);
+ if (!fat_sector)
+ return -1;
+
+ fat_entry = &(fat_sector[off]);
+
+ _content = GET32_A(fat_entry);
+
+ _content &= 0x0FFFFFFF;
+
+ if (_content >= CLUSTER_32(0x0FFFFFF8)) {
+ *content = CLUSTER_32(~0);
+ return 0;
+ } else {
+ *content = CLUSTER_32(_content);
+ return 0;
+ }
+ } else {
+ sec = p_fs->FAT1_start_sector + (loc >> (p_bd->sector_size_bits-2));
+ off = (loc << 2) & p_bd->sector_size_mask;
+
+ fat_sector = FAT_getblk(sb, sec);
+ if (!fat_sector)
+ return -1;
+
+ fat_entry = &(fat_sector[off]);
+ _content = GET32_A(fat_entry);
+
+ if (_content >= CLUSTER_32(0xFFFFFFF8)) {
+ *content = CLUSTER_32(~0);
+ return 0;
+ } else {
+ *content = CLUSTER_32(_content);
+ return 0;
+ }
+ }
+
+ *content = CLUSTER_32(~0);
+ return 0;
+} /* end of __FAT_read */
+
+static s32 __FAT_write(struct super_block *sb, u32 loc, u32 content)
+{
+ s32 off;
+ u32 sec;
+ u8 *fat_sector, *fat_entry;
+ FS_INFO_T *p_fs = &(EXFAT_SB(sb)->fs_info);
+ BD_INFO_T *p_bd = &(EXFAT_SB(sb)->bd_info);
+
+ if (p_fs->vol_type == FAT12) {
+
+ content &= 0x00000FFF;
+
+ sec = p_fs->FAT1_start_sector + ((loc + (loc >> 1)) >> p_bd->sector_size_bits);
+ off = (loc + (loc >> 1)) & p_bd->sector_size_mask;
+
+ fat_sector = FAT_getblk(sb, sec);
+ if (!fat_sector)
+ return -1;
+
+ if (loc & 1) { /* odd */
+
+ content <<= 4;
+
+ if (off == (p_bd->sector_size-1)) {
+ fat_sector[off] = (u8)(content | (fat_sector[off] & 0x0F));
+ FAT_modify(sb, sec);
+
+ fat_sector = FAT_getblk(sb, ++sec);
+ if (!fat_sector)
+ return -1;
+
+ fat_sector[0] = (u8)(content >> 8);
+ } else {
+ fat_entry = &(fat_sector[off]);
+ content |= GET16(fat_entry) & 0x000F;
+
+ SET16(fat_entry, content);
+ }
+ } else { /* even */
+ fat_sector[off] = (u8)(content);
+
+ if (off == (p_bd->sector_size-1)) {
+ fat_sector[off] = (u8)(content);
+ FAT_modify(sb, sec);
+
+ fat_sector = FAT_getblk(sb, ++sec);
+ fat_sector[0] = (u8)((fat_sector[0] & 0xF0) | (content >> 8));
+ } else {
+ fat_entry = &(fat_sector[off]);
+ content |= GET16(fat_entry) & 0xF000;
+
+ SET16(fat_entry, content);
+ }
+ }
+ }
+
+ else if (p_fs->vol_type == FAT16) {
+
+ content &= 0x0000FFFF;
+
+ sec = p_fs->FAT1_start_sector + (loc >> (p_bd->sector_size_bits-1));
+ off = (loc << 1) & p_bd->sector_size_mask;
+
+ fat_sector = FAT_getblk(sb, sec);
+ if (!fat_sector)
+ return -1;
+
+ fat_entry = &(fat_sector[off]);
+
+ SET16_A(fat_entry, content);
+ }
+
+ else if (p_fs->vol_type == FAT32) {
+
+ content &= 0x0FFFFFFF;
+
+ sec = p_fs->FAT1_start_sector + (loc >> (p_bd->sector_size_bits-2));
+ off = (loc << 2) & p_bd->sector_size_mask;
+
+ fat_sector = FAT_getblk(sb, sec);
+ if (!fat_sector)
+ return -1;
+
+ fat_entry = &(fat_sector[off]);
+
+ content |= GET32_A(fat_entry) & 0xF0000000;
+
+ SET32_A(fat_entry, content);
+ }
+
+ else { /* p_fs->vol_type == EXFAT */
+
+ sec = p_fs->FAT1_start_sector + (loc >> (p_bd->sector_size_bits-2));
+ off = (loc << 2) & p_bd->sector_size_mask;
+
+ fat_sector = FAT_getblk(sb, sec);
+ if (!fat_sector)
+ return -1;
+
+ fat_entry = &(fat_sector[off]);
+
+ SET32_A(fat_entry, content);
+ }
+
+ FAT_modify(sb, sec);
+ return 0;
+} /* end of __FAT_write */
+
+u8 *FAT_getblk(struct super_block *sb, u32 sec)
+{
+ BUF_CACHE_T *bp;
+ FS_INFO_T *p_fs = &(EXFAT_SB(sb)->fs_info);
+
+ bp = FAT_cache_find(sb, sec);
+ if (bp != NULL) {
+ move_to_mru(bp, &p_fs->FAT_cache_lru_list);
+ return bp->buf_bh->b_data;
+ }
+
+ bp = FAT_cache_get(sb, sec);
+
+ FAT_cache_remove_hash(bp);
+
+ bp->drv = p_fs->drv;
+ bp->sec = sec;
+ bp->flag = 0;
+
+ FAT_cache_insert_hash(sb, bp);
+
+ if (sector_read(sb, sec, &(bp->buf_bh), 1) != FFS_SUCCESS) {
+ FAT_cache_remove_hash(bp);
+ bp->drv = -1;
+ bp->sec = ~0;
+ bp->flag = 0;
+ bp->buf_bh = NULL;
+
+ move_to_lru(bp, &p_fs->FAT_cache_lru_list);
+ return NULL;
+ }
+
+ return bp->buf_bh->b_data;
+} /* end of FAT_getblk */
+
+void FAT_modify(struct super_block *sb, u32 sec)
+{
+ BUF_CACHE_T *bp;
+
+ bp = FAT_cache_find(sb, sec);
+ if (bp != NULL)
+ sector_write(sb, sec, bp->buf_bh, 0);
+} /* end of FAT_modify */
+
+void FAT_release_all(struct super_block *sb)
+{
+ BUF_CACHE_T *bp;
+ FS_INFO_T *p_fs = &(EXFAT_SB(sb)->fs_info);
+
+ sm_P(&f_sem);
+
+ bp = p_fs->FAT_cache_lru_list.next;
+ while (bp != &p_fs->FAT_cache_lru_list) {
+ if (bp->drv == p_fs->drv) {
+ bp->drv = -1;
+ bp->sec = ~0;
+ bp->flag = 0;
+
+ if (bp->buf_bh) {
+ __brelse(bp->buf_bh);
+ bp->buf_bh = NULL;
+ }
+ }
+ bp = bp->next;
+ }
+
+ sm_V(&f_sem);
+} /* end of FAT_release_all */
+
+void FAT_sync(struct super_block *sb)
+{
+ BUF_CACHE_T *bp;
+ FS_INFO_T *p_fs = &(EXFAT_SB(sb)->fs_info);
+
+ sm_P(&f_sem);
+
+ bp = p_fs->FAT_cache_lru_list.next;
+ while (bp != &p_fs->FAT_cache_lru_list) {
+ if ((bp->drv == p_fs->drv) && (bp->flag & DIRTYBIT)) {
+ sync_dirty_buffer(bp->buf_bh);
+ bp->flag &= ~(DIRTYBIT);
+ }
+ bp = bp->next;
+ }
+
+ sm_V(&f_sem);
+} /* end of FAT_sync */
+
+static BUF_CACHE_T *FAT_cache_find(struct super_block *sb, u32 sec)
+{
+ s32 off;
+ BUF_CACHE_T *bp, *hp;
+ FS_INFO_T *p_fs = &(EXFAT_SB(sb)->fs_info);
+
+ off = (sec + (sec >> p_fs->sectors_per_clu_bits)) & (FAT_CACHE_HASH_SIZE - 1);
+
+ hp = &(p_fs->FAT_cache_hash_list[off]);
+ for (bp = hp->hash_next; bp != hp; bp = bp->hash_next) {
+ if ((bp->drv == p_fs->drv) && (bp->sec == sec)) {
+
+ WARN(!bp->buf_bh, "[EXFAT] FAT_cache has no bh. "
+ "It will make system panic.\n");
+
+ touch_buffer(bp->buf_bh);
+ return bp;
+ }
+ }
+ return NULL;
+} /* end of FAT_cache_find */
+
+static BUF_CACHE_T *FAT_cache_get(struct super_block *sb, u32 sec)
+{
+ BUF_CACHE_T *bp;
+ FS_INFO_T *p_fs = &(EXFAT_SB(sb)->fs_info);
+
+ bp = p_fs->FAT_cache_lru_list.prev;
+
+
+ move_to_mru(bp, &p_fs->FAT_cache_lru_list);
+ return bp;
+} /* end of FAT_cache_get */
+
+static void FAT_cache_insert_hash(struct super_block *sb, BUF_CACHE_T *bp)
+{
+ s32 off;
+ BUF_CACHE_T *hp;
+ FS_INFO_T *p_fs;
+
+ p_fs = &(EXFAT_SB(sb)->fs_info);
+ off = (bp->sec + (bp->sec >> p_fs->sectors_per_clu_bits)) & (FAT_CACHE_HASH_SIZE-1);
+
+ hp = &(p_fs->FAT_cache_hash_list[off]);
+ bp->hash_next = hp->hash_next;
+ bp->hash_prev = hp;
+ hp->hash_next->hash_prev = bp;
+ hp->hash_next = bp;
+} /* end of FAT_cache_insert_hash */
+
+static void FAT_cache_remove_hash(BUF_CACHE_T *bp)
+{
+ (bp->hash_prev)->hash_next = bp->hash_next;
+ (bp->hash_next)->hash_prev = bp->hash_prev;
+} /* end of FAT_cache_remove_hash */
+
+/*======================================================================*/
+/* Buffer Read/Write Functions */
+/*======================================================================*/
+
+u8 *buf_getblk(struct super_block *sb, u32 sec)
+{
+ u8 *buf;
+
+ sm_P(&b_sem);
+
+ buf = __buf_getblk(sb, sec);
+
+ sm_V(&b_sem);
+
+ return buf;
+} /* end of buf_getblk */
+
+static u8 *__buf_getblk(struct super_block *sb, u32 sec)
+{
+ BUF_CACHE_T *bp;
+ FS_INFO_T *p_fs = &(EXFAT_SB(sb)->fs_info);
+
+ bp = buf_cache_find(sb, sec);
+ if (bp != NULL) {
+ move_to_mru(bp, &p_fs->buf_cache_lru_list);
+ return bp->buf_bh->b_data;
+ }
+
+ bp = buf_cache_get(sb, sec);
+
+ buf_cache_remove_hash(bp);
+
+ bp->drv = p_fs->drv;
+ bp->sec = sec;
+ bp->flag = 0;
+
+ buf_cache_insert_hash(sb, bp);
+
+ if (sector_read(sb, sec, &(bp->buf_bh), 1) != FFS_SUCCESS) {
+ buf_cache_remove_hash(bp);
+ bp->drv = -1;
+ bp->sec = ~0;
+ bp->flag = 0;
+ bp->buf_bh = NULL;
+
+ move_to_lru(bp, &p_fs->buf_cache_lru_list);
+ return NULL;
+ }
+
+ return bp->buf_bh->b_data;
+
+} /* end of __buf_getblk */
+
+void buf_modify(struct super_block *sb, u32 sec)
+{
+ BUF_CACHE_T *bp;
+
+ sm_P(&b_sem);
+
+ bp = buf_cache_find(sb, sec);
+ if (likely(bp != NULL))
+ sector_write(sb, sec, bp->buf_bh, 0);
+
+ WARN(!bp, "[EXFAT] failed to find buffer_cache(sector:%u).\n", sec);
+
+ sm_V(&b_sem);
+} /* end of buf_modify */
+
+void buf_lock(struct super_block *sb, u32 sec)
+{
+ BUF_CACHE_T *bp;
+
+ sm_P(&b_sem);
+
+ bp = buf_cache_find(sb, sec);
+ if (likely(bp != NULL))
+ bp->flag |= LOCKBIT;
+
+ WARN(!bp, "[EXFAT] failed to find buffer_cache(sector:%u).\n", sec);
+
+ sm_V(&b_sem);
+} /* end of buf_lock */
+
+void buf_unlock(struct super_block *sb, u32 sec)
+{
+ BUF_CACHE_T *bp;
+
+ sm_P(&b_sem);
+
+ bp = buf_cache_find(sb, sec);
+ if (likely(bp != NULL))
+ bp->flag &= ~(LOCKBIT);
+
+ WARN(!bp, "[EXFAT] failed to find buffer_cache(sector:%u).\n", sec);
+
+ sm_V(&b_sem);
+} /* end of buf_unlock */
+
+void buf_release(struct super_block *sb, u32 sec)
+{
+ BUF_CACHE_T *bp;
+ FS_INFO_T *p_fs = &(EXFAT_SB(sb)->fs_info);
+
+ sm_P(&b_sem);
+
+ bp = buf_cache_find(sb, sec);
+ if (likely(bp != NULL)) {
+ bp->drv = -1;
+ bp->sec = ~0;
+ bp->flag = 0;
+
+ if (bp->buf_bh) {
+ __brelse(bp->buf_bh);
+ bp->buf_bh = NULL;
+ }
+
+ move_to_lru(bp, &p_fs->buf_cache_lru_list);
+ }
+
+ sm_V(&b_sem);
+} /* end of buf_release */
+
+void buf_release_all(struct super_block *sb)
+{
+ BUF_CACHE_T *bp;
+ FS_INFO_T *p_fs = &(EXFAT_SB(sb)->fs_info);
+
+ sm_P(&b_sem);
+
+ bp = p_fs->buf_cache_lru_list.next;
+ while (bp != &p_fs->buf_cache_lru_list) {
+ if (bp->drv == p_fs->drv) {
+ bp->drv = -1;
+ bp->sec = ~0;
+ bp->flag = 0;
+
+ if (bp->buf_bh) {
+ __brelse(bp->buf_bh);
+ bp->buf_bh = NULL;
+ }
+ }
+ bp = bp->next;
+ }
+
+ sm_V(&b_sem);
+} /* end of buf_release_all */
+
+void buf_sync(struct super_block *sb)
+{
+ BUF_CACHE_T *bp;
+ FS_INFO_T *p_fs = &(EXFAT_SB(sb)->fs_info);
+
+ sm_P(&b_sem);
+
+ bp = p_fs->buf_cache_lru_list.next;
+ while (bp != &p_fs->buf_cache_lru_list) {
+ if ((bp->drv == p_fs->drv) && (bp->flag & DIRTYBIT)) {
+ sync_dirty_buffer(bp->buf_bh);
+ bp->flag &= ~(DIRTYBIT);
+ }
+ bp = bp->next;
+ }
+
+ sm_V(&b_sem);
+} /* end of buf_sync */
+
+static BUF_CACHE_T *buf_cache_find(struct super_block *sb, u32 sec)
+{
+ s32 off;
+ BUF_CACHE_T *bp, *hp;
+ FS_INFO_T *p_fs = &(EXFAT_SB(sb)->fs_info);
+
+ off = (sec + (sec >> p_fs->sectors_per_clu_bits)) & (BUF_CACHE_HASH_SIZE - 1);
+
+ hp = &(p_fs->buf_cache_hash_list[off]);
+ for (bp = hp->hash_next; bp != hp; bp = bp->hash_next) {
+ if ((bp->drv == p_fs->drv) && (bp->sec == sec)) {
+ touch_buffer(bp->buf_bh);
+ return bp;
+ }
+ }
+ return NULL;
+} /* end of buf_cache_find */
+
+static BUF_CACHE_T *buf_cache_get(struct super_block *sb, u32 sec)
+{
+ BUF_CACHE_T *bp;
+ FS_INFO_T *p_fs = &(EXFAT_SB(sb)->fs_info);
+
+ bp = p_fs->buf_cache_lru_list.prev;
+ while (bp->flag & LOCKBIT)
+ bp = bp->prev;
+
+
+ move_to_mru(bp, &p_fs->buf_cache_lru_list);
+ return bp;
+} /* end of buf_cache_get */
+
+static void buf_cache_insert_hash(struct super_block *sb, BUF_CACHE_T *bp)
+{
+ s32 off;
+ BUF_CACHE_T *hp;
+ FS_INFO_T *p_fs;
+
+ p_fs = &(EXFAT_SB(sb)->fs_info);
+ off = (bp->sec + (bp->sec >> p_fs->sectors_per_clu_bits)) & (BUF_CACHE_HASH_SIZE-1);
+
+ hp = &(p_fs->buf_cache_hash_list[off]);
+ bp->hash_next = hp->hash_next;
+ bp->hash_prev = hp;
+ hp->hash_next->hash_prev = bp;
+ hp->hash_next = bp;
+} /* end of buf_cache_insert_hash */
+
+static void buf_cache_remove_hash(BUF_CACHE_T *bp)
+{
+ (bp->hash_prev)->hash_next = bp->hash_next;
+ (bp->hash_next)->hash_prev = bp->hash_prev;
+} /* end of buf_cache_remove_hash */
+
+/*======================================================================*/
+/* Local Function Definitions */
+/*======================================================================*/
+
+static void push_to_mru(BUF_CACHE_T *bp, BUF_CACHE_T *list)
+{
+ bp->next = list->next;
+ bp->prev = list;
+ list->next->prev = bp;
+ list->next = bp;
+} /* end of buf_cache_push_to_mru */
+
+static void push_to_lru(BUF_CACHE_T *bp, BUF_CACHE_T *list)
+{
+ bp->prev = list->prev;
+ bp->next = list;
+ list->prev->next = bp;
+ list->prev = bp;
+} /* end of buf_cache_push_to_lru */
+
+static void move_to_mru(BUF_CACHE_T *bp, BUF_CACHE_T *list)
+{
+ bp->prev->next = bp->next;
+ bp->next->prev = bp->prev;
+ push_to_mru(bp, list);
+} /* end of buf_cache_move_to_mru */
+
+static void move_to_lru(BUF_CACHE_T *bp, BUF_CACHE_T *list)
+{
+ bp->prev->next = bp->next;
+ bp->next->prev = bp->prev;
+ push_to_lru(bp, list);
+} /* end of buf_cache_move_to_lru */
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-13 00:25:43 +0000