Commit b438aca4 authored by Hirofumi Ogawa's avatar Hirofumi Ogawa Committed by Arnaldo Carvalho de Melo

[PATCH] FAT cluster chain cache per superblock (4/5)

This shifts the data position caches from module to per-superblock, and
cleanups.
parent ff3345fd
...@@ -12,9 +12,6 @@ ...@@ -12,9 +12,6 @@
#include <linux/msdos_fs.h> #include <linux/msdos_fs.h>
#include <linux/buffer_head.h> #include <linux/buffer_head.h>
static struct fat_cache *fat_cache,cache[FAT_CACHE];
static spinlock_t fat_cache_lock = SPIN_LOCK_UNLOCKED;
int __fat_access(struct super_block *sb, int nr, int new_value) int __fat_access(struct super_block *sb, int nr, int new_value)
{ {
struct msdos_sb_info *sbi = MSDOS_SB(sb); struct msdos_sb_info *sbi = MSDOS_SB(sb);
...@@ -133,148 +130,139 @@ int fat_access(struct super_block *sb, int nr, int new_value) ...@@ -133,148 +130,139 @@ int fat_access(struct super_block *sb, int nr, int new_value)
return next; return next;
} }
void fat_cache_init(void) void fat_cache_init(struct super_block *sb)
{ {
static int initialized; struct msdos_sb_info *sbi = MSDOS_SB(sb);
int count; int count;
spin_lock(&fat_cache_lock); spin_lock_init(&sbi->cache_lock);
if (initialized) {
spin_unlock(&fat_cache_lock); for (count = 0; count < FAT_CACHE_NR - 1; count++) {
return; sbi->cache_array[count].start_cluster = 0;
} sbi->cache_array[count].next = &sbi->cache_array[count + 1];
fat_cache = &cache[0];
for (count = 0; count < FAT_CACHE; count++) {
cache[count].sb = NULL;
cache[count].next = count == FAT_CACHE-1 ? NULL :
&cache[count+1];
} }
initialized = 1; sbi->cache_array[count].start_cluster = 0;
spin_unlock(&fat_cache_lock); sbi->cache_array[count].next = NULL;
sbi->cache = sbi->cache_array;
} }
void fat_cache_lookup(struct inode *inode, int cluster, int *f_clu, int *d_clu)
void fat_cache_lookup(struct inode *inode,int cluster,int *f_clu,int *d_clu)
{ {
struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
struct fat_cache *walk; struct fat_cache *walk;
int first = MSDOS_I(inode)->i_start; int first;
first = MSDOS_I(inode)->i_start;
if (!first) if (!first)
return; return;
spin_lock(&fat_cache_lock);
for (walk = fat_cache; walk; walk = walk->next) spin_lock(&sbi->cache_lock);
if (inode->i_sb == walk->sb for (walk = sbi->cache; walk; walk = walk->next) {
&& walk->start_cluster == first if (walk->start_cluster == first
&& walk->file_cluster <= cluster && walk->file_cluster <= cluster
&& walk->file_cluster > *f_clu) { && walk->file_cluster > *f_clu) {
*d_clu = walk->disk_cluster; *d_clu = walk->disk_cluster;
*f_clu = walk->file_cluster;
#ifdef DEBUG #ifdef DEBUG
printk("cache hit: %d (%d)\n",walk->file_cluster,*d_clu); printk("cache hit: %d (%d)\n", *f_clu, *d_clu);
#endif #endif
if ((*f_clu = walk->file_cluster) == cluster) { if (*f_clu == cluster)
spin_unlock(&fat_cache_lock); goto out;
return;
} }
} }
spin_unlock(&fat_cache_lock);
#ifdef DEBUG #ifdef DEBUG
printk("cache miss\n"); printk("cache miss\n");
#endif #endif
out:
spin_unlock(&sbi->cache_lock);
} }
#ifdef DEBUG #ifdef DEBUG
static void list_cache(void) static void list_cache(struct super_block *sb)
{ {
struct msdos_sb_info *sbi = MSDOS_SB(sb);
struct fat_cache *walk; struct fat_cache *walk;
for (walk = fat_cache; walk; walk = walk->next) { for (walk = sbi->cache; walk; walk = walk->next) {
if (walk->sb) if (walk->start_cluster)
printk("<%s,%d>(%d,%d) ", walk->sb->s_id, printk("<%s,%d>(%d,%d) ", sb->s_id,
walk->start_cluster, walk->file_cluster, walk->start_cluster, walk->file_cluster,
walk->disk_cluster); walk->disk_cluster);
else printk("-- "); else
printk("-- ");
} }
printk("\n"); printk("\n");
} }
#endif #endif
/*
void fat_cache_add(struct inode *inode,int f_clu,int d_clu) * Cache invalidation occurs rarely, thus the LRU chain is not updated. It
* fixes itself after a while.
*/
static void __fat_cache_inval_inode(struct inode *inode)
{ {
struct fat_cache *walk,*last; struct fat_cache *walk;
int first = MSDOS_I(inode)->i_start; int first = MSDOS_I(inode)->i_start;
for (walk = MSDOS_SB(inode->i_sb)->cache; walk; walk = walk->next)
if (walk->start_cluster == first)
walk->start_cluster = 0;
}
void fat_cache_inval_inode(struct inode *inode)
{
struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
spin_lock(&sbi->cache_lock);
__fat_cache_inval_inode(inode);
spin_unlock(&sbi->cache_lock);
}
void fat_cache_add(struct inode *inode, int f_clu, int d_clu)
{
struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
struct fat_cache *walk, *last;
int first;
first = MSDOS_I(inode)->i_start;
if (!first)
return;
last = NULL; last = NULL;
spin_lock(&fat_cache_lock); spin_lock(&sbi->cache_lock);
for (walk = fat_cache; walk->next; walk = (last = walk)->next) for (walk = sbi->cache; walk->next; walk = (last = walk)->next) {
if (inode->i_sb == walk->sb if (walk->start_cluster == first &&
&& walk->start_cluster == first walk->file_cluster == f_clu) {
&& walk->file_cluster == f_clu) {
if (walk->disk_cluster != d_clu) { if (walk->disk_cluster != d_clu) {
printk(KERN_ERR "FAT: cache corruption" printk(KERN_ERR "FAT: cache corruption"
" (ino %lu)\n", inode->i_ino); " (ino %lu)\n", inode->i_ino);
spin_unlock(&fat_cache_lock); __fat_cache_inval_inode(inode);
fat_cache_inval_inode(inode); goto out;
return;
} }
if (last == NULL)
goto out;
/* update LRU */ /* update LRU */
if (last == NULL) {
spin_unlock(&fat_cache_lock);
return;
}
last->next = walk->next; last->next = walk->next;
walk->next = fat_cache; walk->next = sbi->cache;
fat_cache = walk; sbi->cache = walk;
#ifdef DEBUG #ifdef DEBUG
list_cache(); list_cache();
#endif #endif
spin_unlock(&fat_cache_lock); goto out;
return; }
} }
walk->sb = inode->i_sb;
walk->start_cluster = first; walk->start_cluster = first;
walk->file_cluster = f_clu; walk->file_cluster = f_clu;
walk->disk_cluster = d_clu; walk->disk_cluster = d_clu;
last->next = NULL; last->next = NULL;
walk->next = fat_cache; walk->next = sbi->cache;
fat_cache = walk; sbi->cache = walk;
spin_unlock(&fat_cache_lock);
#ifdef DEBUG #ifdef DEBUG
list_cache(); list_cache();
#endif #endif
out:
spin_unlock(&sbi->cache_lock);
} }
/* Cache invalidation occurs rarely, thus the LRU chain is not updated. It
fixes itself after a while. */
void fat_cache_inval_inode(struct inode *inode)
{
struct fat_cache *walk;
int first = MSDOS_I(inode)->i_start;
spin_lock(&fat_cache_lock);
for (walk = fat_cache; walk; walk = walk->next)
if (walk->sb == inode->i_sb
&& walk->start_cluster == first)
walk->sb = NULL;
spin_unlock(&fat_cache_lock);
}
void fat_cache_inval_dev(struct super_block *sb)
{
struct fat_cache *walk;
spin_lock(&fat_cache_lock);
for (walk = fat_cache; walk; walk = walk->next)
if (walk->sb == sb)
walk->sb = 0;
spin_unlock(&fat_cache_lock);
}
static int fat_get_cluster(struct inode *inode, int cluster) static int fat_get_cluster(struct inode *inode, int cluster)
{ {
struct super_block *sb = inode->i_sb; struct super_block *sb = inode->i_sb;
......
...@@ -160,7 +160,6 @@ void fat_put_super(struct super_block *sb) ...@@ -160,7 +160,6 @@ void fat_put_super(struct super_block *sb)
struct msdos_sb_info *sbi = MSDOS_SB(sb); struct msdos_sb_info *sbi = MSDOS_SB(sb);
fat_clusters_flush(sb); fat_clusters_flush(sb);
fat_cache_inval_dev(sb);
if (sbi->nls_disk) { if (sbi->nls_disk) {
unload_nls(sbi->nls_disk); unload_nls(sbi->nls_disk);
sbi->nls_disk = NULL; sbi->nls_disk = NULL;
...@@ -766,7 +765,7 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, ...@@ -766,7 +765,7 @@ int fat_fill_super(struct super_block *sb, void *data, int silent,
if (!parse_options(data, isvfat, &debug, &sbi->options)) if (!parse_options(data, isvfat, &debug, &sbi->options))
goto out_fail; goto out_fail;
fat_cache_init(); fat_cache_init(sb);
/* set up enough so that it can read an inode */ /* set up enough so that it can read an inode */
init_MUTEX(&sbi->fat_lock); init_MUTEX(&sbi->fat_lock);
......
...@@ -27,8 +27,6 @@ struct statfs; ...@@ -27,8 +27,6 @@ struct statfs;
#define MSDOS_SUPER_MAGIC 0x4d44 /* MD */ #define MSDOS_SUPER_MAGIC 0x4d44 /* MD */
#define FAT_CACHE 8 /* FAT cache size */
#define ATTR_NONE 0 /* no attribute bits */ #define ATTR_NONE 0 /* no attribute bits */
#define ATTR_RO 1 /* read-only */ #define ATTR_RO 1 /* read-only */
#define ATTR_HIDDEN 2 /* hidden */ #define ATTR_HIDDEN 2 /* hidden */
...@@ -204,14 +202,6 @@ static inline struct msdos_inode_info *MSDOS_I(struct inode *inode) ...@@ -204,14 +202,6 @@ static inline struct msdos_inode_info *MSDOS_I(struct inode *inode)
return container_of(inode, struct msdos_inode_info, vfs_inode); return container_of(inode, struct msdos_inode_info, vfs_inode);
} }
struct fat_cache {
struct super_block *sb; /* fs in question. NULL means unused */
int start_cluster; /* first cluster of the chain. */
int file_cluster; /* cluster number in the file. */
int disk_cluster; /* cluster number on disk. */
struct fat_cache *next; /* next cache entry */
};
static inline void fat16_towchar(wchar_t *dst, const __u8 *src, size_t len) static inline void fat16_towchar(wchar_t *dst, const __u8 *src, size_t len)
{ {
#ifdef __BIG_ENDIAN #ifdef __BIG_ENDIAN
...@@ -242,12 +232,11 @@ static inline void fatwchar_to16(__u8 *dst, const wchar_t *src, size_t len) ...@@ -242,12 +232,11 @@ static inline void fatwchar_to16(__u8 *dst, const wchar_t *src, size_t len)
extern int fat_access(struct super_block *sb, int nr, int new_value); extern int fat_access(struct super_block *sb, int nr, int new_value);
extern int __fat_access(struct super_block *sb, int nr, int new_value); extern int __fat_access(struct super_block *sb, int nr, int new_value);
extern int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys); extern int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys);
extern void fat_cache_init(void); extern void fat_cache_init(struct super_block *sb);
extern void fat_cache_lookup(struct inode *inode, int cluster, int *f_clu, extern void fat_cache_lookup(struct inode *inode, int cluster, int *f_clu,
int *d_clu); int *d_clu);
extern void fat_cache_add(struct inode *inode, int f_clu, int d_clu); extern void fat_cache_add(struct inode *inode, int f_clu, int d_clu);
extern void fat_cache_inval_inode(struct inode *inode); extern void fat_cache_inval_inode(struct inode *inode);
extern void fat_cache_inval_dev(struct super_block *sb);
extern int fat_free(struct inode *inode, int skip); extern int fat_free(struct inode *inode, int skip);
/* fat/dir.c */ /* fat/dir.c */
......
...@@ -26,6 +26,15 @@ struct fat_mount_options { ...@@ -26,6 +26,15 @@ struct fat_mount_options {
nocase:1; /* Does this need case conversion? 0=need case conversion*/ nocase:1; /* Does this need case conversion? 0=need case conversion*/
}; };
#define FAT_CACHE_NR 8 /* number of FAT cache */
struct fat_cache {
int start_cluster; /* first cluster of the chain. */
int file_cluster; /* cluster number in the file. */
int disk_cluster; /* cluster number on disk. */
struct fat_cache *next; /* next cache entry */
};
struct msdos_sb_info { struct msdos_sb_info {
unsigned short cluster_size; /* sectors/cluster */ unsigned short cluster_size; /* sectors/cluster */
unsigned short cluster_bits; /* sectors/cluster */ unsigned short cluster_bits; /* sectors/cluster */
...@@ -47,6 +56,9 @@ struct msdos_sb_info { ...@@ -47,6 +56,9 @@ struct msdos_sb_info {
void *dir_ops; /* Opaque; default directory operations */ void *dir_ops; /* Opaque; default directory operations */
int dir_per_block; /* dir entries per block */ int dir_per_block; /* dir entries per block */
int dir_per_block_bits; /* log2(dir_per_block) */ int dir_per_block_bits; /* log2(dir_per_block) */
spinlock_t cache_lock;
struct fat_cache cache_array[FAT_CACHE_NR], *cache;
}; };
#endif #endif
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