fs/Kconfig: move fat out

[safe/jmp/linux-2.6] / fs / fat / fatent.c

diff --git a/fs/fat/fatent.c b/fs/fat/fatent.c
index ab171ea..da6eea4 100644 (file)
--- a/fs/fat/fatent.c
+++ b/fs/fat/fatent.c
@@ -6,6 +6,8 @@
 #include <linux/module.h>
 #include <linux/fs.h>
 #include <linux/msdos_fs.h>
+#include <linux/blkdev.h>
+#include "fat.h"
 
 struct fatent_operations {
        void (*ent_blocknr)(struct super_block *, int, int *, sector_t *);
@@ -17,6 +19,8 @@ struct fatent_operations {
        int (*ent_next)(struct fat_entry *);
 };
 
+static DEFINE_SPINLOCK(fat12_entry_lock);
+
 static void fat12_ent_blocknr(struct super_block *sb, int entry,
                              int *offset, sector_t *blocknr)
 {
@@ -89,8 +93,7 @@ static int fat12_ent_bread(struct super_block *sb, struct fat_entry *fatent,
 err_brelse:
        brelse(bhs[0]);
 err:
-       printk(KERN_ERR "FAT: FAT read failed (blocknr %llu)\n",
-              (unsigned long long)blocknr);
+       printk(KERN_ERR "FAT: FAT read failed (blocknr %llu)\n", (llu)blocknr);
        return -EIO;
 }
 
@@ -103,7 +106,7 @@ static int fat_ent_bread(struct super_block *sb, struct fat_entry *fatent,
        fatent->bhs[0] = sb_bread(sb, blocknr);
        if (!fatent->bhs[0]) {
                printk(KERN_ERR "FAT: FAT read failed (blocknr %llu)\n",
-                      (unsigned long long)blocknr);
+                      (llu)blocknr);
                return -EIO;
        }
        fatent->nr_bhs = 1;
@@ -116,10 +119,13 @@ static int fat12_ent_get(struct fat_entry *fatent)
        u8 **ent12_p = fatent->u.ent12_p;
        int next;
 
+       spin_lock(&fat12_entry_lock);
        if (fatent->entry & 1)
                next = (*ent12_p[0] >> 4) | (*ent12_p[1] << 4);
        else
                next = (*ent12_p[1] << 8) | *ent12_p[0];
+       spin_unlock(&fat12_entry_lock);
+
        next &= 0x0fff;
        if (next >= BAD_FAT12)
                next = FAT_ENT_EOF;
@@ -151,6 +157,7 @@ static void fat12_ent_put(struct fat_entry *fatent, int new)
        if (new == FAT_ENT_EOF)
                new = EOF_FAT12;
 
+       spin_lock(&fat12_entry_lock);
        if (fatent->entry & 1) {
                *ent12_p[0] = (new << 4) | (*ent12_p[0] & 0x0f);
                *ent12_p[1] = new >> 4;
@@ -158,6 +165,7 @@ static void fat12_ent_put(struct fat_entry *fatent, int new)
                *ent12_p[0] = new & 0xff;
                *ent12_p[1] = (*ent12_p[1] & 0xf0) | (new >> 8);
        }
+       spin_unlock(&fat12_entry_lock);
 
        mark_buffer_dirty(fatent->bhs[0]);
        if (fatent->nr_bhs == 2)
@@ -308,10 +316,20 @@ static inline int fat_ent_update_ptr(struct super_block *sb,
        /* Is this fatent's blocks including this entry? */
        if (!fatent->nr_bhs || bhs[0]->b_blocknr != blocknr)
                return 0;
-       /* Does this entry need the next block? */
-       if (sbi->fat_bits == 12 && (offset + 1) >= sb->s_blocksize) {
-               if (fatent->nr_bhs != 2 || bhs[1]->b_blocknr != (blocknr + 1))
-                       return 0;
+       if (sbi->fat_bits == 12) {
+               if ((offset + 1) < sb->s_blocksize) {
+                       /* This entry is on bhs[0]. */
+                       if (fatent->nr_bhs == 2) {
+                               brelse(bhs[1]);
+                               fatent->nr_bhs = 1;
+                       }
+               } else {
+                       /* This entry needs the next block. */
+                       if (fatent->nr_bhs != 2)
+                               return 0;
+                       if (bhs[1]->b_blocknr != (blocknr + 1))
+                               return 0;
+               }
        }
        ops->ent_set_ptr(fatent, offset);
        return 1;
@@ -443,7 +461,8 @@ int fat_alloc_clusters(struct inode *inode, int *cluster, int nr_cluster)
        BUG_ON(nr_cluster > (MAX_BUF_PER_PAGE / 2));    /* fixed limit */
 
        lock_fat(sbi);
-       if (sbi->free_clusters != -1 && sbi->free_clusters < nr_cluster) {
+       if (sbi->free_clusters != -1 && sbi->free_clus_valid &&
+           sbi->free_clusters < nr_cluster) {
                unlock_fat(sbi);
                return -ENOSPC;
        }
@@ -497,6 +516,7 @@ int fat_alloc_clusters(struct inode *inode, int *cluster, int nr_cluster)
 
        /* Couldn't allocate the free entries */
        sbi->free_clusters = 0;
+       sbi->free_clus_valid = 1;
        sb->s_dirt = 1;
        err = -ENOSPC;
 
@@ -526,6 +546,7 @@ int fat_free_clusters(struct inode *inode, int cluster)
        struct fat_entry fatent;
        struct buffer_head *bhs[MAX_BUF_PER_PAGE];
        int i, err, nr_bhs;
+       int first_cl = cluster;
 
        nr_bhs = 0;
        fatent_init(&fatent);
@@ -537,11 +558,23 @@ int fat_free_clusters(struct inode *inode, int cluster)
                        goto error;
                } else if (cluster == FAT_ENT_FREE) {
                        fat_fs_panic(sb, "%s: deleting FAT entry beyond EOF",
-                                    __FUNCTION__);
+                                    __func__);
                        err = -EIO;
                        goto error;
                }
 
+               /* 
+                * Issue discard for the sectors we no longer care about,
+                * batching contiguous clusters into one request
+                */
+               if (cluster != fatent.entry + 1) {
+                       int nr_clus = fatent.entry - first_cl + 1;
+
+                       sb_issue_discard(sb, fat_clus_to_blknr(sbi, first_cl),
+                                        nr_clus * sbi->sec_per_clus);
+                       first_cl = cluster;
+               }
+
                ops->ent_put(&fatent, FAT_ENT_FREE);
                if (sbi->free_clusters != -1) {
                        sbi->free_clusters++;
@@ -576,28 +609,54 @@ error:
                brelse(bhs[i]);
        unlock_fat(sbi);
 
-       fat_clusters_flush(sb);
-
        return err;
 }
 
 EXPORT_SYMBOL_GPL(fat_free_clusters);
 
+/* 128kb is the whole sectors for FAT12 and FAT16 */
+#define FAT_READA_SIZE         (128 * 1024)
+
+static void fat_ent_reada(struct super_block *sb, struct fat_entry *fatent,
+                         unsigned long reada_blocks)
+{
+       struct fatent_operations *ops = MSDOS_SB(sb)->fatent_ops;
+       sector_t blocknr;
+       int i, offset;
+
+       ops->ent_blocknr(sb, fatent->entry, &offset, &blocknr);
+
+       for (i = 0; i < reada_blocks; i++)
+               sb_breadahead(sb, blocknr + i);
+}
+
 int fat_count_free_clusters(struct super_block *sb)
 {
        struct msdos_sb_info *sbi = MSDOS_SB(sb);
        struct fatent_operations *ops = sbi->fatent_ops;
        struct fat_entry fatent;
+       unsigned long reada_blocks, reada_mask, cur_block;
        int err = 0, free;
 
        lock_fat(sbi);
-       if (sbi->free_clusters != -1)
+       if (sbi->free_clusters != -1 && sbi->free_clus_valid)
                goto out;
 
+       reada_blocks = FAT_READA_SIZE >> sb->s_blocksize_bits;
+       reada_mask = reada_blocks - 1;
+       cur_block = 0;
+
        free = 0;
        fatent_init(&fatent);
        fatent_set_entry(&fatent, FAT_START_ENT);
        while (fatent.entry < sbi->max_cluster) {
+               /* readahead of fat blocks */
+               if ((cur_block & reada_mask) == 0) {
+                       unsigned long rest = sbi->fat_length - cur_block;
+                       fat_ent_reada(sb, &fatent, min(reada_blocks, rest));
+               }
+               cur_block++;
+
                err = fat_ent_read_block(sb, &fatent);
                if (err)
                        goto out;
@@ -608,6 +667,7 @@ int fat_count_free_clusters(struct super_block *sb)
                } while (fat_ent_next(sbi, &fatent));
        }
        sbi->free_clusters = free;
+       sbi->free_clus_valid = 1;
        sb->s_dirt = 1;
        fatent_brelse(&fatent);
 out: