Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 612 insertions, 0 deletions

diff --git a/fs/fat/fatent.c b/fs/fat/fatent.c
new file mode 100644
index 00000000000..4164cd54c4d
--- /dev/null
+++ b/fs/fat/fatent.c
@@ -0,0 +1,612 @@
+/*
+ * Copyright (C) 2004, OGAWA Hirofumi
+ * Released under GPL v2.
+ */
+
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/msdos_fs.h>
+
+struct fatent_operations {
+        void (*ent_blocknr)(struct super_block *, int, int *, sector_t *);
+        void (*ent_set_ptr)(struct fat_entry *, int);
+        int (*ent_bread)(struct super_block *, struct fat_entry *,
+                         int, sector_t);
+        int (*ent_get)(struct fat_entry *);
+        void (*ent_put)(struct fat_entry *, int);
+        int (*ent_next)(struct fat_entry *);
+};
+
+static void fat12_ent_blocknr(struct super_block *sb, int entry,
+                              int *offset, sector_t *blocknr)
+{
+        struct msdos_sb_info *sbi = MSDOS_SB(sb);
+        int bytes = entry + (entry >> 1);
+        WARN_ON(entry < FAT_START_ENT || sbi->max_cluster <= entry);
+        *offset = bytes & (sb->s_blocksize - 1);
+        *blocknr = sbi->fat_start + (bytes >> sb->s_blocksize_bits);
+}
+
+static void fat_ent_blocknr(struct super_block *sb, int entry,
+                            int *offset, sector_t *blocknr)
+{
+        struct msdos_sb_info *sbi = MSDOS_SB(sb);
+        int bytes = (entry << sbi->fatent_shift);
+        WARN_ON(entry < FAT_START_ENT || sbi->max_cluster <= entry);
+        *offset = bytes & (sb->s_blocksize - 1);
+        *blocknr = sbi->fat_start + (bytes >> sb->s_blocksize_bits);
+}
+
+static void fat12_ent_set_ptr(struct fat_entry *fatent, int offset)
+{
+        struct buffer_head **bhs = fatent->bhs;
+        if (fatent->nr_bhs == 1) {
+                WARN_ON(offset >= (bhs[0]->b_size - 1));
+                fatent->u.ent12_p[0] = bhs[0]->b_data + offset;
+                fatent->u.ent12_p[1] = bhs[0]->b_data + (offset + 1);
+        } else {
+                WARN_ON(offset != (bhs[0]->b_size - 1));
+                fatent->u.ent12_p[0] = bhs[0]->b_data + offset;
+                fatent->u.ent12_p[1] = bhs[1]->b_data;
+        }
+}
+
+static void fat16_ent_set_ptr(struct fat_entry *fatent, int offset)
+{
+        WARN_ON(offset & (2 - 1));
+        fatent->u.ent16_p = (__le16 *)(fatent->bhs[0]->b_data + offset);
+}
+
+static void fat32_ent_set_ptr(struct fat_entry *fatent, int offset)
+{
+        WARN_ON(offset & (4 - 1));
+        fatent->u.ent32_p = (__le32 *)(fatent->bhs[0]->b_data + offset);
+}
+
+static int fat12_ent_bread(struct super_block *sb, struct fat_entry *fatent,
+                           int offset, sector_t blocknr)
+{
+        struct buffer_head **bhs = fatent->bhs;
+
+        WARN_ON(blocknr < MSDOS_SB(sb)->fat_start);
+        bhs[0] = sb_bread(sb, blocknr);
+        if (!bhs[0])
+                goto err;
+
+        if ((offset + 1) < sb->s_blocksize)
+                fatent->nr_bhs = 1;
+        else {
+                /* This entry is block boundary, it needs the next block */
+                blocknr++;
+                bhs[1] = sb_bread(sb, blocknr);
+                if (!bhs[1])
+                        goto err_brelse;
+                fatent->nr_bhs = 2;
+        }
+        fat12_ent_set_ptr(fatent, offset);
+        return 0;
+
+err_brelse:
+        brelse(bhs[0]);
+err:
+        printk(KERN_ERR "FAT: FAT read failed (blocknr %llu)\n",
+               (unsigned long long)blocknr);
+        return -EIO;
+}
+
+static int fat_ent_bread(struct super_block *sb, struct fat_entry *fatent,
+                         int offset, sector_t blocknr)
+{
+        struct fatent_operations *ops = MSDOS_SB(sb)->fatent_ops;
+
+        WARN_ON(blocknr < MSDOS_SB(sb)->fat_start);
+        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);
+                return -EIO;
+        }
+        fatent->nr_bhs = 1;
+        ops->ent_set_ptr(fatent, offset);
+        return 0;
+}
+
+static int fat12_ent_get(struct fat_entry *fatent)
+{
+        u8 **ent12_p = fatent->u.ent12_p;
+        int next;
+
+        if (fatent->entry & 1)
+                next = (*ent12_p[0] >> 4) | (*ent12_p[1] << 4);
+        else
+                next = (*ent12_p[1] << 8) | *ent12_p[0];
+        next &= 0x0fff;
+        if (next >= BAD_FAT12)
+                next = FAT_ENT_EOF;
+        return next;
+}
+
+static int fat16_ent_get(struct fat_entry *fatent)
+{
+        int next = le16_to_cpu(*fatent->u.ent16_p);
+        WARN_ON((unsigned long)fatent->u.ent16_p & (2 - 1));
+        if (next >= BAD_FAT16)
+                next = FAT_ENT_EOF;
+        return next;
+}
+
+static int fat32_ent_get(struct fat_entry *fatent)
+{
+        int next = le32_to_cpu(*fatent->u.ent32_p) & 0x0fffffff;
+        WARN_ON((unsigned long)fatent->u.ent32_p & (4 - 1));
+        if (next >= BAD_FAT32)
+                next = FAT_ENT_EOF;
+        return next;
+}
+
+static void fat12_ent_put(struct fat_entry *fatent, int new)
+{
+        u8 **ent12_p = fatent->u.ent12_p;
+
+        if (new == FAT_ENT_EOF)
+                new = EOF_FAT12;
+
+        if (fatent->entry & 1) {
+                *ent12_p[0] = (new << 4) | (*ent12_p[0] & 0x0f);
+                *ent12_p[1] = new >> 4;
+        } else {
+                *ent12_p[0] = new & 0xff;
+                *ent12_p[1] = (*ent12_p[1] & 0xf0) | (new >> 8);
+        }
+
+        mark_buffer_dirty(fatent->bhs[0]);
+        if (fatent->nr_bhs == 2)
+                mark_buffer_dirty(fatent->bhs[1]);
+}
+
+static void fat16_ent_put(struct fat_entry *fatent, int new)
+{
+        if (new == FAT_ENT_EOF)
+                new = EOF_FAT16;
+
+        *fatent->u.ent16_p = cpu_to_le16(new);
+        mark_buffer_dirty(fatent->bhs[0]);
+}
+
+static void fat32_ent_put(struct fat_entry *fatent, int new)
+{
+        if (new == FAT_ENT_EOF)
+                new = EOF_FAT32;
+
+        WARN_ON(new & 0xf0000000);
+        new |= le32_to_cpu(*fatent->u.ent32_p) & ~0x0fffffff;
+        *fatent->u.ent32_p = cpu_to_le32(new);
+        mark_buffer_dirty(fatent->bhs[0]);
+}
+
+static int fat12_ent_next(struct fat_entry *fatent)
+{
+        u8 **ent12_p = fatent->u.ent12_p;
+        struct buffer_head **bhs = fatent->bhs;
+        u8 *nextp = ent12_p[1] + 1 + (fatent->entry & 1);
+
+        fatent->entry++;
+        if (fatent->nr_bhs == 1) {
+                WARN_ON(ent12_p[0] > (u8 *)(bhs[0]->b_data + (bhs[0]->b_size - 2)));
+                WARN_ON(ent12_p[1] > (u8 *)(bhs[0]->b_data + (bhs[0]->b_size - 1)));
+                if (nextp < (u8 *)(bhs[0]->b_data + (bhs[0]->b_size - 1))) {
+                        ent12_p[0] = nextp - 1;
+                        ent12_p[1] = nextp;
+                        return 1;
+                }
+        } else {
+                WARN_ON(ent12_p[0] != (u8 *)(bhs[0]->b_data + (bhs[0]->b_size - 1)));
+                WARN_ON(ent12_p[1] != (u8 *)bhs[1]->b_data);
+                ent12_p[0] = nextp - 1;
+                ent12_p[1] = nextp;
+                brelse(bhs[0]);
+                bhs[0] = bhs[1];
+                fatent->nr_bhs = 1;
+                return 1;
+        }
+        ent12_p[0] = NULL;
+        ent12_p[1] = NULL;
+        return 0;
+}
+
+static int fat16_ent_next(struct fat_entry *fatent)
+{
+        const struct buffer_head *bh = fatent->bhs[0];
+        fatent->entry++;
+        if (fatent->u.ent16_p < (__le16 *)(bh->b_data + (bh->b_size - 2))) {
+                fatent->u.ent16_p++;
+                return 1;
+        }
+        fatent->u.ent16_p = NULL;
+        return 0;
+}
+
+static int fat32_ent_next(struct fat_entry *fatent)
+{
+        const struct buffer_head *bh = fatent->bhs[0];
+        fatent->entry++;
+        if (fatent->u.ent32_p < (__le32 *)(bh->b_data + (bh->b_size - 4))) {
+                fatent->u.ent32_p++;
+                return 1;
+        }
+        fatent->u.ent32_p = NULL;
+        return 0;
+}
+
+static struct fatent_operations fat12_ops = {
+        .ent_blocknr    = fat12_ent_blocknr,
+        .ent_set_ptr    = fat12_ent_set_ptr,
+        .ent_bread      = fat12_ent_bread,
+        .ent_get        = fat12_ent_get,
+        .ent_put        = fat12_ent_put,
+        .ent_next       = fat12_ent_next,
+};
+
+static struct fatent_operations fat16_ops = {
+        .ent_blocknr    = fat_ent_blocknr,
+        .ent_set_ptr    = fat16_ent_set_ptr,
+        .ent_bread      = fat_ent_bread,
+        .ent_get        = fat16_ent_get,
+        .ent_put        = fat16_ent_put,
+        .ent_next       = fat16_ent_next,
+};
+
+static struct fatent_operations fat32_ops = {
+        .ent_blocknr    = fat_ent_blocknr,
+        .ent_set_ptr    = fat32_ent_set_ptr,
+        .ent_bread      = fat_ent_bread,
+        .ent_get        = fat32_ent_get,
+        .ent_put        = fat32_ent_put,
+        .ent_next       = fat32_ent_next,
+};
+
+static inline void lock_fat(struct msdos_sb_info *sbi)
+{
+        down(&sbi->fat_lock);
+}
+
+static inline void unlock_fat(struct msdos_sb_info *sbi)
+{
+        up(&sbi->fat_lock);
+}
+
+void fat_ent_access_init(struct super_block *sb)
+{
+        struct msdos_sb_info *sbi = MSDOS_SB(sb);
+
+        init_MUTEX(&sbi->fat_lock);
+
+        switch (sbi->fat_bits) {
+        case 32:
+                sbi->fatent_shift = 2;
+                sbi->fatent_ops = &fat32_ops;
+                break;
+        case 16:
+                sbi->fatent_shift = 1;
+                sbi->fatent_ops = &fat16_ops;
+                break;
+        case 12:
+                sbi->fatent_shift = -1;
+                sbi->fatent_ops = &fat12_ops;
+                break;
+        }
+}
+
+static inline int fat_ent_update_ptr(struct super_block *sb,
+                                     struct fat_entry *fatent,
+                                     int offset, sector_t blocknr)
+{
+        struct msdos_sb_info *sbi = MSDOS_SB(sb);
+        struct fatent_operations *ops = sbi->fatent_ops;
+        struct buffer_head **bhs = fatent->bhs;
+
+        /* 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;
+        }
+        ops->ent_set_ptr(fatent, offset);
+        return 1;
+}
+
+int fat_ent_read(struct inode *inode, struct fat_entry *fatent, int entry)
+{
+        struct super_block *sb = inode->i_sb;
+        struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
+        struct fatent_operations *ops = sbi->fatent_ops;
+        int err, offset;
+        sector_t blocknr;
+
+        if (entry < FAT_START_ENT || sbi->max_cluster <= entry) {
+                fatent_brelse(fatent);
+                fat_fs_panic(sb, "invalid access to FAT (entry 0x%08x)", entry);
+                return -EIO;
+        }
+
+        fatent_set_entry(fatent, entry);
+        ops->ent_blocknr(sb, entry, &offset, &blocknr);
+
+        if (!fat_ent_update_ptr(sb, fatent, offset, blocknr)) {
+                fatent_brelse(fatent);
+                err = ops->ent_bread(sb, fatent, offset, blocknr);
+                if (err)
+                        return err;
+        }
+        return ops->ent_get(fatent);
+}
+
+/* FIXME: We can write the blocks as more big chunk. */
+static int fat_mirror_bhs(struct super_block *sb, struct buffer_head **bhs,
+                          int nr_bhs)
+{
+        struct msdos_sb_info *sbi = MSDOS_SB(sb);
+        struct buffer_head *c_bh;
+        int err, n, copy;
+
+        err = 0;
+        for (copy = 1; copy < sbi->fats; copy++) {
+                sector_t backup_fat = sbi->fat_length * copy;
+
+                for (n = 0; n < nr_bhs; n++) {
+                        c_bh = sb_getblk(sb, backup_fat + bhs[n]->b_blocknr);
+                        if (!c_bh) {
+                                err = -ENOMEM;
+                                goto error;
+                        }
+                        memcpy(c_bh->b_data, bhs[n]->b_data, sb->s_blocksize);
+                        set_buffer_uptodate(c_bh);
+                        mark_buffer_dirty(c_bh);
+                        if (sb->s_flags & MS_SYNCHRONOUS)
+                                err = sync_dirty_buffer(c_bh);
+                        brelse(c_bh);
+                        if (err)
+                                goto error;
+                }
+        }
+error:
+        return err;
+}
+
+int fat_ent_write(struct inode *inode, struct fat_entry *fatent,
+                  int new, int wait)
+{
+        struct super_block *sb = inode->i_sb;
+        struct fatent_operations *ops = MSDOS_SB(sb)->fatent_ops;
+        int err;
+
+        ops->ent_put(fatent, new);
+        if (wait) {
+                err = fat_sync_bhs(fatent->bhs, fatent->nr_bhs);
+                if (err)
+                        return err;
+        }
+        return fat_mirror_bhs(sb, fatent->bhs, fatent->nr_bhs);
+}
+
+static inline int fat_ent_next(struct msdos_sb_info *sbi,
+                               struct fat_entry *fatent)
+{
+        if (sbi->fatent_ops->ent_next(fatent)) {
+                if (fatent->entry < sbi->max_cluster)
+                        return 1;
+        }
+        return 0;
+}
+
+static inline int fat_ent_read_block(struct super_block *sb,
+                                     struct fat_entry *fatent)
+{
+        struct fatent_operations *ops = MSDOS_SB(sb)->fatent_ops;
+        sector_t blocknr;
+        int offset;
+
+        fatent_brelse(fatent);
+        ops->ent_blocknr(sb, fatent->entry, &offset, &blocknr);
+        return ops->ent_bread(sb, fatent, offset, blocknr);
+}
+
+static void fat_collect_bhs(struct buffer_head **bhs, int *nr_bhs,
+                            struct fat_entry *fatent)
+{
+        int n, i;
+
+        for (n = 0; n < fatent->nr_bhs; n++) {
+                for (i = 0; i < *nr_bhs; i++) {
+                        if (fatent->bhs[n] == bhs[i])
+                                break;
+                }
+                if (i == *nr_bhs) {
+                        get_bh(fatent->bhs[n]);
+                        bhs[i] = fatent->bhs[n];
+                        (*nr_bhs)++;
+                }
+        }
+}
+
+int fat_alloc_clusters(struct inode *inode, int *cluster, int nr_cluster)
+{
+        struct super_block *sb = inode->i_sb;
+        struct msdos_sb_info *sbi = MSDOS_SB(sb);
+        struct fatent_operations *ops = sbi->fatent_ops;
+        struct fat_entry fatent, prev_ent;
+        struct buffer_head *bhs[MAX_BUF_PER_PAGE];
+        int i, count, err, nr_bhs, idx_clus;
+
+        BUG_ON(nr_cluster > (MAX_BUF_PER_PAGE / 2));    /* fixed limit */
+
+        lock_fat(sbi);
+        if (sbi->free_clusters != -1 && sbi->free_clusters < nr_cluster) {
+                unlock_fat(sbi);
+                return -ENOSPC;
+        }
+
+        err = nr_bhs = idx_clus = 0;
+        count = FAT_START_ENT;
+        fatent_init(&prev_ent);
+        fatent_init(&fatent);
+        fatent_set_entry(&fatent, sbi->prev_free + 1);
+        while (count < sbi->max_cluster) {
+                if (fatent.entry >= sbi->max_cluster)
+                        fatent.entry = FAT_START_ENT;
+                fatent_set_entry(&fatent, fatent.entry);
+                err = fat_ent_read_block(sb, &fatent);
+                if (err)
+                        goto out;
+
+                /* Find the free entries in a block */
+                do {
+                        if (ops->ent_get(&fatent) == FAT_ENT_FREE) {
+                                int entry = fatent.entry;
+
+                                /* make the cluster chain */
+                                ops->ent_put(&fatent, FAT_ENT_EOF);
+                                if (prev_ent.nr_bhs)
+                                        ops->ent_put(&prev_ent, entry);
+
+                                fat_collect_bhs(bhs, &nr_bhs, &fatent);
+
+                                sbi->prev_free = entry;
+                                if (sbi->free_clusters != -1)
+                                        sbi->free_clusters--;
+
+                                cluster[idx_clus] = entry;
+                                idx_clus++;
+                                if (idx_clus == nr_cluster)
+                                        goto out;
+
+                                /*
+                                 * fat_collect_bhs() gets ref-count of bhs,
+                                 * so we can still use the prev_ent.
+                                 */
+                                prev_ent = fatent;
+                        }
+                        count++;
+                        if (count == sbi->max_cluster)
+                                break;
+                } while (fat_ent_next(sbi, &fatent));
+        }
+
+        /* Couldn't allocate the free entries */
+        sbi->free_clusters = 0;
+        err = -ENOSPC;
+
+out:
+        unlock_fat(sbi);
+        fatent_brelse(&fatent);
+        if (!err) {
+                if (inode_needs_sync(inode))
+                        err = fat_sync_bhs(bhs, nr_bhs);
+                if (!err)
+                        err = fat_mirror_bhs(sb, bhs, nr_bhs);
+        }
+        for (i = 0; i < nr_bhs; i++)
+                brelse(bhs[i]);
+        fat_clusters_flush(sb);
+
+        if (err && idx_clus)
+                fat_free_clusters(inode, cluster[0]);
+
+        return err;
+}
+
+int fat_free_clusters(struct inode *inode, int cluster)
+{
+        struct super_block *sb = inode->i_sb;
+        struct msdos_sb_info *sbi = MSDOS_SB(sb);
+        struct fatent_operations *ops = sbi->fatent_ops;
+        struct fat_entry fatent;
+        struct buffer_head *bhs[MAX_BUF_PER_PAGE];
+        int i, err, nr_bhs;
+
+        nr_bhs = 0;
+        fatent_init(&fatent);
+        lock_fat(sbi);
+        do {
+                cluster = fat_ent_read(inode, &fatent, cluster);
+                if (cluster < 0) {
+                        err = cluster;
+                        goto error;
+                } else if (cluster == FAT_ENT_FREE) {
+                        fat_fs_panic(sb, "%s: deleting FAT entry beyond EOF",
+                                     __FUNCTION__);
+                        err = -EIO;
+                        goto error;
+                }
+
+                ops->ent_put(&fatent, FAT_ENT_FREE);
+                if (sbi->free_clusters != -1)
+                        sbi->free_clusters++;
+
+                if (nr_bhs + fatent.nr_bhs > MAX_BUF_PER_PAGE) {
+                        if (sb->s_flags & MS_SYNCHRONOUS) {
+                                err = fat_sync_bhs(bhs, nr_bhs);
+                                if (err)
+                                        goto error;
+                        }
+                        err = fat_mirror_bhs(sb, bhs, nr_bhs);
+                        if (err)
+                                goto error;
+                        for (i = 0; i < nr_bhs; i++)
+                                brelse(bhs[i]);
+                        nr_bhs = 0;
+                }
+                fat_collect_bhs(bhs, &nr_bhs, &fatent);
+        } while (cluster != FAT_ENT_EOF);
+
+        if (sb->s_flags & MS_SYNCHRONOUS) {
+                err = fat_sync_bhs(bhs, nr_bhs);
+                if (err)
+                        goto error;
+        }
+        err = fat_mirror_bhs(sb, bhs, nr_bhs);
+error:
+        fatent_brelse(&fatent);
+        for (i = 0; i < nr_bhs; i++)
+                brelse(bhs[i]);
+        unlock_fat(sbi);
+
+        fat_clusters_flush(sb);
+
+        return err;
+}
+
+EXPORT_SYMBOL(fat_free_clusters);
+
+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;
+        int err = 0, free;
+
+        lock_fat(sbi);
+        if (sbi->free_clusters != -1)
+                goto out;
+
+        free = 0;
+        fatent_init(&fatent);
+        fatent_set_entry(&fatent, FAT_START_ENT);
+        while (fatent.entry < sbi->max_cluster) {
+                err = fat_ent_read_block(sb, &fatent);
+                if (err)
+                        goto out;
+
+                do {
+                        if (ops->ent_get(&fatent) == FAT_ENT_FREE)
+                                free++;
+                } while (fat_ent_next(sbi, &fatent));
+        }
+        sbi->free_clusters = free;
+        fatent_brelse(&fatent);
+out:
+        unlock_fat(sbi);
+        return err;
+}