Linux-2.6.12-rc2v2.6.12-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, 920 insertions, 0 deletions

diff --git a/fs/affs/file.c b/fs/affs/file.c
new file mode 100644
index 000000000000..6744924b6905
--- /dev/null
+++ b/fs/affs/file.c
@@ -0,0 +1,920 @@
+/*
+ *  linux/fs/affs/file.c
+ *
+ *  (c) 1996  Hans-Joachim Widmaier - Rewritten
+ *
+ *  (C) 1993  Ray Burr - Modified for Amiga FFS filesystem.
+ *
+ *  (C) 1992  Eric Youngdale Modified for ISO 9660 filesystem.
+ *
+ *  (C) 1991  Linus Torvalds - minix filesystem
+ *
+ *  affs regular file handling primitives
+ */
+
+#include "affs.h"
+
+#if PAGE_SIZE < 4096
+#error PAGE_SIZE must be at least 4096
+#endif
+
+static int affs_grow_extcache(struct inode *inode, u32 lc_idx);
+static struct buffer_head *affs_alloc_extblock(struct inode *inode, struct buffer_head *bh, u32 ext);
+static inline struct buffer_head *affs_get_extblock(struct inode *inode, u32 ext);
+static struct buffer_head *affs_get_extblock_slow(struct inode *inode, u32 ext);
+static ssize_t affs_file_write(struct file *filp, const char __user *buf, size_t count, loff_t *ppos);
+static int affs_file_open(struct inode *inode, struct file *filp);
+static int affs_file_release(struct inode *inode, struct file *filp);
+
+struct file_operations affs_file_operations = {
+        .llseek         = generic_file_llseek,
+        .read           = generic_file_read,
+        .write          = affs_file_write,
+        .mmap           = generic_file_mmap,
+        .open           = affs_file_open,
+        .release        = affs_file_release,
+        .fsync          = file_fsync,
+        .sendfile       = generic_file_sendfile,
+};
+
+struct inode_operations affs_file_inode_operations = {
+        .truncate       = affs_truncate,
+        .setattr        = affs_notify_change,
+};
+
+static int
+affs_file_open(struct inode *inode, struct file *filp)
+{
+        if (atomic_read(&filp->f_count) != 1)
+                return 0;
+        pr_debug("AFFS: open(%d)\n", AFFS_I(inode)->i_opencnt);
+        AFFS_I(inode)->i_opencnt++;
+        return 0;
+}
+
+static int
+affs_file_release(struct inode *inode, struct file *filp)
+{
+        if (atomic_read(&filp->f_count) != 0)
+                return 0;
+        pr_debug("AFFS: release(%d)\n", AFFS_I(inode)->i_opencnt);
+        AFFS_I(inode)->i_opencnt--;
+        if (!AFFS_I(inode)->i_opencnt)
+                affs_free_prealloc(inode);
+
+        return 0;
+}
+
+static int
+affs_grow_extcache(struct inode *inode, u32 lc_idx)
+{
+        struct super_block      *sb = inode->i_sb;
+        struct buffer_head      *bh;
+        u32 lc_max;
+        int i, j, key;
+
+        if (!AFFS_I(inode)->i_lc) {
+                char *ptr = (char *)get_zeroed_page(GFP_NOFS);
+                if (!ptr)
+                        return -ENOMEM;
+                AFFS_I(inode)->i_lc = (u32 *)ptr;
+                AFFS_I(inode)->i_ac = (struct affs_ext_key *)(ptr + AFFS_CACHE_SIZE / 2);
+        }
+
+        lc_max = AFFS_LC_SIZE << AFFS_I(inode)->i_lc_shift;
+
+        if (AFFS_I(inode)->i_extcnt > lc_max) {
+                u32 lc_shift, lc_mask, tmp, off;
+
+                /* need to recalculate linear cache, start from old size */
+                lc_shift = AFFS_I(inode)->i_lc_shift;
+                tmp = (AFFS_I(inode)->i_extcnt / AFFS_LC_SIZE) >> lc_shift;
+                for (; tmp; tmp >>= 1)
+                        lc_shift++;
+                lc_mask = (1 << lc_shift) - 1;
+
+                /* fix idx and old size to new shift */
+                lc_idx >>= (lc_shift - AFFS_I(inode)->i_lc_shift);
+                AFFS_I(inode)->i_lc_size >>= (lc_shift - AFFS_I(inode)->i_lc_shift);
+
+                /* first shrink old cache to make more space */
+                off = 1 << (lc_shift - AFFS_I(inode)->i_lc_shift);
+                for (i = 1, j = off; j < AFFS_LC_SIZE; i++, j += off)
+                        AFFS_I(inode)->i_ac[i] = AFFS_I(inode)->i_ac[j];
+
+                AFFS_I(inode)->i_lc_shift = lc_shift;
+                AFFS_I(inode)->i_lc_mask = lc_mask;
+        }
+
+        /* fill cache to the needed index */
+        i = AFFS_I(inode)->i_lc_size;
+        AFFS_I(inode)->i_lc_size = lc_idx + 1;
+        for (; i <= lc_idx; i++) {
+                if (!i) {
+                        AFFS_I(inode)->i_lc[0] = inode->i_ino;
+                        continue;
+                }
+                key = AFFS_I(inode)->i_lc[i - 1];
+                j = AFFS_I(inode)->i_lc_mask + 1;
+                // unlock cache
+                for (; j > 0; j--) {
+                        bh = affs_bread(sb, key);
+                        if (!bh)
+                                goto err;
+                        key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
+                        affs_brelse(bh);
+                }
+                // lock cache
+                AFFS_I(inode)->i_lc[i] = key;
+        }
+
+        return 0;
+
+err:
+        // lock cache
+        return -EIO;
+}
+
+static struct buffer_head *
+affs_alloc_extblock(struct inode *inode, struct buffer_head *bh, u32 ext)
+{
+        struct super_block *sb = inode->i_sb;
+        struct buffer_head *new_bh;
+        u32 blocknr, tmp;
+
+        blocknr = affs_alloc_block(inode, bh->b_blocknr);
+        if (!blocknr)
+                return ERR_PTR(-ENOSPC);
+
+        new_bh = affs_getzeroblk(sb, blocknr);
+        if (!new_bh) {
+                affs_free_block(sb, blocknr);
+                return ERR_PTR(-EIO);
+        }
+
+        AFFS_HEAD(new_bh)->ptype = cpu_to_be32(T_LIST);
+        AFFS_HEAD(new_bh)->key = cpu_to_be32(blocknr);
+        AFFS_TAIL(sb, new_bh)->stype = cpu_to_be32(ST_FILE);
+        AFFS_TAIL(sb, new_bh)->parent = cpu_to_be32(inode->i_ino);
+        affs_fix_checksum(sb, new_bh);
+
+        mark_buffer_dirty_inode(new_bh, inode);
+
+        tmp = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
+        if (tmp)
+                affs_warning(sb, "alloc_ext", "previous extension set (%x)", tmp);
+        AFFS_TAIL(sb, bh)->extension = cpu_to_be32(blocknr);
+        affs_adjust_checksum(bh, blocknr - tmp);
+        mark_buffer_dirty_inode(bh, inode);
+
+        AFFS_I(inode)->i_extcnt++;
+        mark_inode_dirty(inode);
+
+        return new_bh;
+}
+
+static inline struct buffer_head *
+affs_get_extblock(struct inode *inode, u32 ext)
+{
+        /* inline the simplest case: same extended block as last time */
+        struct buffer_head *bh = AFFS_I(inode)->i_ext_bh;
+        if (ext == AFFS_I(inode)->i_ext_last)
+                atomic_inc(&bh->b_count);
+        else
+                /* we have to do more (not inlined) */
+                bh = affs_get_extblock_slow(inode, ext);
+
+        return bh;
+}
+
+static struct buffer_head *
+affs_get_extblock_slow(struct inode *inode, u32 ext)
+{
+        struct super_block *sb = inode->i_sb;
+        struct buffer_head *bh;
+        u32 ext_key;
+        u32 lc_idx, lc_off, ac_idx;
+        u32 tmp, idx;
+
+        if (ext == AFFS_I(inode)->i_ext_last + 1) {
+                /* read the next extended block from the current one */
+                bh = AFFS_I(inode)->i_ext_bh;
+                ext_key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
+                if (ext < AFFS_I(inode)->i_extcnt)
+                        goto read_ext;
+                if (ext > AFFS_I(inode)->i_extcnt)
+                        BUG();
+                bh = affs_alloc_extblock(inode, bh, ext);
+                if (IS_ERR(bh))
+                        return bh;
+                goto store_ext;
+        }
+
+        if (ext == 0) {
+                /* we seek back to the file header block */
+                ext_key = inode->i_ino;
+                goto read_ext;
+        }
+
+        if (ext >= AFFS_I(inode)->i_extcnt) {
+                struct buffer_head *prev_bh;
+
+                /* allocate a new extended block */
+                if (ext > AFFS_I(inode)->i_extcnt)
+                        BUG();
+
+                /* get previous extended block */
+                prev_bh = affs_get_extblock(inode, ext - 1);
+                if (IS_ERR(prev_bh))
+                        return prev_bh;
+                bh = affs_alloc_extblock(inode, prev_bh, ext);
+                affs_brelse(prev_bh);
+                if (IS_ERR(bh))
+                        return bh;
+                goto store_ext;
+        }
+
+again:
+        /* check if there is an extended cache and whether it's large enough */
+        lc_idx = ext >> AFFS_I(inode)->i_lc_shift;
+        lc_off = ext & AFFS_I(inode)->i_lc_mask;
+
+        if (lc_idx >= AFFS_I(inode)->i_lc_size) {
+                int err;
+
+                err = affs_grow_extcache(inode, lc_idx);
+                if (err)
+                        return ERR_PTR(err);
+                goto again;
+        }
+
+        /* every n'th key we find in the linear cache */
+        if (!lc_off) {
+                ext_key = AFFS_I(inode)->i_lc[lc_idx];
+                goto read_ext;
+        }
+
+        /* maybe it's still in the associative cache */
+        ac_idx = (ext - lc_idx - 1) & AFFS_AC_MASK;
+        if (AFFS_I(inode)->i_ac[ac_idx].ext == ext) {
+                ext_key = AFFS_I(inode)->i_ac[ac_idx].key;
+                goto read_ext;
+        }
+
+        /* try to find one of the previous extended blocks */
+        tmp = ext;
+        idx = ac_idx;
+        while (--tmp, --lc_off > 0) {
+                idx = (idx - 1) & AFFS_AC_MASK;
+                if (AFFS_I(inode)->i_ac[idx].ext == tmp) {
+                        ext_key = AFFS_I(inode)->i_ac[idx].key;
+                        goto find_ext;
+                }
+        }
+
+        /* fall back to the linear cache */
+        ext_key = AFFS_I(inode)->i_lc[lc_idx];
+find_ext:
+        /* read all extended blocks until we find the one we need */
+        //unlock cache
+        do {
+                bh = affs_bread(sb, ext_key);
+                if (!bh)
+                        goto err_bread;
+                ext_key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
+                affs_brelse(bh);
+                tmp++;
+        } while (tmp < ext);
+        //lock cache
+
+        /* store it in the associative cache */
+        // recalculate ac_idx?
+        AFFS_I(inode)->i_ac[ac_idx].ext = ext;
+        AFFS_I(inode)->i_ac[ac_idx].key = ext_key;
+
+read_ext:
+        /* finally read the right extended block */
+        //unlock cache
+        bh = affs_bread(sb, ext_key);
+        if (!bh)
+                goto err_bread;
+        //lock cache
+
+store_ext:
+        /* release old cached extended block and store the new one */
+        affs_brelse(AFFS_I(inode)->i_ext_bh);
+        AFFS_I(inode)->i_ext_last = ext;
+        AFFS_I(inode)->i_ext_bh = bh;
+        atomic_inc(&bh->b_count);
+
+        return bh;
+
+err_bread:
+        affs_brelse(bh);
+        return ERR_PTR(-EIO);
+}
+
+static int
+affs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh_result, int create)
+{
+        struct super_block      *sb = inode->i_sb;
+        struct buffer_head      *ext_bh;
+        u32                      ext;
+
+        pr_debug("AFFS: get_block(%u, %lu)\n", (u32)inode->i_ino, (unsigned long)block);
+
+
+        if (block > (sector_t)0x7fffffffUL)
+                BUG();
+
+        if (block >= AFFS_I(inode)->i_blkcnt) {
+                if (block > AFFS_I(inode)->i_blkcnt || !create)
+                        goto err_big;
+        } else
+                create = 0;
+
+        //lock cache
+        affs_lock_ext(inode);
+
+        ext = (u32)block / AFFS_SB(sb)->s_hashsize;
+        block -= ext * AFFS_SB(sb)->s_hashsize;
+        ext_bh = affs_get_extblock(inode, ext);
+        if (IS_ERR(ext_bh))
+                goto err_ext;
+        map_bh(bh_result, sb, (sector_t)be32_to_cpu(AFFS_BLOCK(sb, ext_bh, block)));
+
+        if (create) {
+                u32 blocknr = affs_alloc_block(inode, ext_bh->b_blocknr);
+                if (!blocknr)
+                        goto err_alloc;
+                set_buffer_new(bh_result);
+                AFFS_I(inode)->mmu_private += AFFS_SB(sb)->s_data_blksize;
+                AFFS_I(inode)->i_blkcnt++;
+
+                /* store new block */
+                if (bh_result->b_blocknr)
+                        affs_warning(sb, "get_block", "block already set (%x)", bh_result->b_blocknr);
+                AFFS_BLOCK(sb, ext_bh, block) = cpu_to_be32(blocknr);
+                AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(block + 1);
+                affs_adjust_checksum(ext_bh, blocknr - bh_result->b_blocknr + 1);
+                bh_result->b_blocknr = blocknr;
+
+                if (!block) {
+                        /* insert first block into header block */
+                        u32 tmp = be32_to_cpu(AFFS_HEAD(ext_bh)->first_data);
+                        if (tmp)
+                                affs_warning(sb, "get_block", "first block already set (%d)", tmp);
+                        AFFS_HEAD(ext_bh)->first_data = cpu_to_be32(blocknr);
+                        affs_adjust_checksum(ext_bh, blocknr - tmp);
+                }
+        }
+
+        affs_brelse(ext_bh);
+        //unlock cache
+        affs_unlock_ext(inode);
+        return 0;
+
+err_big:
+        affs_error(inode->i_sb,"get_block","strange block request %d", block);
+        return -EIO;
+err_ext:
+        // unlock cache
+        affs_unlock_ext(inode);
+        return PTR_ERR(ext_bh);
+err_alloc:
+        brelse(ext_bh);
+        clear_buffer_mapped(bh_result);
+        bh_result->b_bdev = NULL;
+        // unlock cache
+        affs_unlock_ext(inode);
+        return -ENOSPC;
+}
+
+static int affs_writepage(struct page *page, struct writeback_control *wbc)
+{
+        return block_write_full_page(page, affs_get_block, wbc);
+}
+static int affs_readpage(struct file *file, struct page *page)
+{
+        return block_read_full_page(page, affs_get_block);
+}
+static int affs_prepare_write(struct file *file, struct page *page, unsigned from, unsigned to)
+{
+        return cont_prepare_write(page, from, to, affs_get_block,
+                &AFFS_I(page->mapping->host)->mmu_private);
+}
+static sector_t _affs_bmap(struct address_space *mapping, sector_t block)
+{
+        return generic_block_bmap(mapping,block,affs_get_block);
+}
+struct address_space_operations affs_aops = {
+        .readpage = affs_readpage,
+        .writepage = affs_writepage,
+        .sync_page = block_sync_page,
+        .prepare_write = affs_prepare_write,
+        .commit_write = generic_commit_write,
+        .bmap = _affs_bmap
+};
+
+static inline struct buffer_head *
+affs_bread_ino(struct inode *inode, int block, int create)
+{
+        struct buffer_head *bh, tmp_bh;
+        int err;
+
+        tmp_bh.b_state = 0;
+        err = affs_get_block(inode, block, &tmp_bh, create);
+        if (!err) {
+                bh = affs_bread(inode->i_sb, tmp_bh.b_blocknr);
+                if (bh) {
+                        bh->b_state |= tmp_bh.b_state;
+                        return bh;
+                }
+                err = -EIO;
+        }
+        return ERR_PTR(err);
+}
+
+static inline struct buffer_head *
+affs_getzeroblk_ino(struct inode *inode, int block)
+{
+        struct buffer_head *bh, tmp_bh;
+        int err;
+
+        tmp_bh.b_state = 0;
+        err = affs_get_block(inode, block, &tmp_bh, 1);
+        if (!err) {
+                bh = affs_getzeroblk(inode->i_sb, tmp_bh.b_blocknr);
+                if (bh) {
+                        bh->b_state |= tmp_bh.b_state;
+                        return bh;
+                }
+                err = -EIO;
+        }
+        return ERR_PTR(err);
+}
+
+static inline struct buffer_head *
+affs_getemptyblk_ino(struct inode *inode, int block)
+{
+        struct buffer_head *bh, tmp_bh;
+        int err;
+
+        tmp_bh.b_state = 0;
+        err = affs_get_block(inode, block, &tmp_bh, 1);
+        if (!err) {
+                bh = affs_getemptyblk(inode->i_sb, tmp_bh.b_blocknr);
+                if (bh) {
+                        bh->b_state |= tmp_bh.b_state;
+                        return bh;
+                }
+                err = -EIO;
+        }
+        return ERR_PTR(err);
+}
+
+static ssize_t
+affs_file_write(struct file *file, const char __user *buf,
+                size_t count, loff_t *ppos)
+{
+        ssize_t retval;
+
+        retval = generic_file_write (file, buf, count, ppos);
+        if (retval >0) {
+                struct inode *inode = file->f_dentry->d_inode;
+                inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
+                mark_inode_dirty(inode);
+        }
+        return retval;
+}
+
+static int
+affs_do_readpage_ofs(struct file *file, struct page *page, unsigned from, unsigned to)
+{
+        struct inode *inode = page->mapping->host;
+        struct super_block *sb = inode->i_sb;
+        struct buffer_head *bh;
+        char *data;
+        u32 bidx, boff, bsize;
+        u32 tmp;
+
+        pr_debug("AFFS: read_page(%u, %ld, %d, %d)\n", (u32)inode->i_ino, page->index, from, to);
+        if (from > to || to > PAGE_CACHE_SIZE)
+                BUG();
+        kmap(page);
+        data = page_address(page);
+        bsize = AFFS_SB(sb)->s_data_blksize;
+        tmp = (page->index << PAGE_CACHE_SHIFT) + from;
+        bidx = tmp / bsize;
+        boff = tmp % bsize;
+
+        while (from < to) {
+                bh = affs_bread_ino(inode, bidx, 0);
+                if (IS_ERR(bh))
+                        return PTR_ERR(bh);
+                tmp = min(bsize - boff, to - from);
+                if (from + tmp > to || tmp > bsize)
+                        BUG();
+                memcpy(data + from, AFFS_DATA(bh) + boff, tmp);
+                affs_brelse(bh);
+                bidx++;
+                from += tmp;
+                boff = 0;
+        }
+        flush_dcache_page(page);
+        kunmap(page);
+        return 0;
+}
+
+static int
+affs_extent_file_ofs(struct inode *inode, u32 newsize)
+{
+        struct super_block *sb = inode->i_sb;
+        struct buffer_head *bh, *prev_bh;
+        u32 bidx, boff;
+        u32 size, bsize;
+        u32 tmp;
+
+        pr_debug("AFFS: extent_file(%u, %d)\n", (u32)inode->i_ino, newsize);
+        bsize = AFFS_SB(sb)->s_data_blksize;
+        bh = NULL;
+        size = AFFS_I(inode)->mmu_private;
+        bidx = size / bsize;
+        boff = size % bsize;
+        if (boff) {
+                bh = affs_bread_ino(inode, bidx, 0);
+                if (IS_ERR(bh))
+                        return PTR_ERR(bh);
+                tmp = min(bsize - boff, newsize - size);
+                if (boff + tmp > bsize || tmp > bsize)
+                        BUG();
+                memset(AFFS_DATA(bh) + boff, 0, tmp);
+                AFFS_DATA_HEAD(bh)->size = cpu_to_be32(be32_to_cpu(AFFS_DATA_HEAD(bh)->size) + tmp);
+                affs_fix_checksum(sb, bh);
+                mark_buffer_dirty_inode(bh, inode);
+                size += tmp;
+                bidx++;
+        } else if (bidx) {
+                bh = affs_bread_ino(inode, bidx - 1, 0);
+                if (IS_ERR(bh))
+                        return PTR_ERR(bh);
+        }
+
+        while (size < newsize) {
+                prev_bh = bh;
+                bh = affs_getzeroblk_ino(inode, bidx);
+                if (IS_ERR(bh))
+                        goto out;
+                tmp = min(bsize, newsize - size);
+                if (tmp > bsize)
+                        BUG();
+                AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
+                AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
+                AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
+                AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
+                affs_fix_checksum(sb, bh);
+                bh->b_state &= ~(1UL << BH_New);
+                mark_buffer_dirty_inode(bh, inode);
+                if (prev_bh) {
+                        u32 tmp = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
+                        if (tmp)
+                                affs_warning(sb, "extent_file_ofs", "next block already set for %d (%d)", bidx, tmp);
+                        AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
+                        affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp);
+                        mark_buffer_dirty_inode(prev_bh, inode);
+                        affs_brelse(prev_bh);
+                }
+                size += bsize;
+                bidx++;
+        }
+        affs_brelse(bh);
+        inode->i_size = AFFS_I(inode)->mmu_private = newsize;
+        return 0;
+
+out:
+        inode->i_size = AFFS_I(inode)->mmu_private = newsize;
+        return PTR_ERR(bh);
+}
+
+static int
+affs_readpage_ofs(struct file *file, struct page *page)
+{
+        struct inode *inode = page->mapping->host;
+        u32 to;
+        int err;
+
+        pr_debug("AFFS: read_page(%u, %ld)\n", (u32)inode->i_ino, page->index);
+        to = PAGE_CACHE_SIZE;
+        if (((page->index + 1) << PAGE_CACHE_SHIFT) > inode->i_size) {
+                to = inode->i_size & ~PAGE_CACHE_MASK;
+                memset(page_address(page) + to, 0, PAGE_CACHE_SIZE - to);
+        }
+
+        err = affs_do_readpage_ofs(file, page, 0, to);
+        if (!err)
+                SetPageUptodate(page);
+        unlock_page(page);
+        return err;
+}
+
+static int affs_prepare_write_ofs(struct file *file, struct page *page, unsigned from, unsigned to)
+{
+        struct inode *inode = page->mapping->host;
+        u32 size, offset;
+        u32 tmp;
+        int err = 0;
+
+        pr_debug("AFFS: prepare_write(%u, %ld, %d, %d)\n", (u32)inode->i_ino, page->index, from, to);
+        offset = page->index << PAGE_CACHE_SHIFT;
+        if (offset + from > AFFS_I(inode)->mmu_private) {
+                err = affs_extent_file_ofs(inode, offset + from);
+                if (err)
+                        return err;
+        }
+        size = inode->i_size;
+
+        if (PageUptodate(page))
+                return 0;
+
+        if (from) {
+                err = affs_do_readpage_ofs(file, page, 0, from);
+                if (err)
+                        return err;
+        }
+        if (to < PAGE_CACHE_SIZE) {
+                char *kaddr = kmap_atomic(page, KM_USER0);
+
+                memset(kaddr + to, 0, PAGE_CACHE_SIZE - to);
+                flush_dcache_page(page);
+                kunmap_atomic(kaddr, KM_USER0);
+                if (size > offset + to) {
+                        if (size < offset + PAGE_CACHE_SIZE)
+                                tmp = size & ~PAGE_CACHE_MASK;
+                        else
+                                tmp = PAGE_CACHE_SIZE;
+                        err = affs_do_readpage_ofs(file, page, to, tmp);
+                }
+        }
+        return err;
+}
+
+static int affs_commit_write_ofs(struct file *file, struct page *page, unsigned from, unsigned to)
+{
+        struct inode *inode = page->mapping->host;
+        struct super_block *sb = inode->i_sb;
+        struct buffer_head *bh, *prev_bh;
+        char *data;
+        u32 bidx, boff, bsize;
+        u32 tmp;
+        int written;
+
+        pr_debug("AFFS: commit_write(%u, %ld, %d, %d)\n", (u32)inode->i_ino, page->index, from, to);
+        bsize = AFFS_SB(sb)->s_data_blksize;
+        data = page_address(page);
+
+        bh = NULL;
+        written = 0;
+        tmp = (page->index << PAGE_CACHE_SHIFT) + from;
+        bidx = tmp / bsize;
+        boff = tmp % bsize;
+        if (boff) {
+                bh = affs_bread_ino(inode, bidx, 0);
+                if (IS_ERR(bh))
+                        return PTR_ERR(bh);
+                tmp = min(bsize - boff, to - from);
+                if (boff + tmp > bsize || tmp > bsize)
+                        BUG();
+                memcpy(AFFS_DATA(bh) + boff, data + from, tmp);
+                AFFS_DATA_HEAD(bh)->size = cpu_to_be32(be32_to_cpu(AFFS_DATA_HEAD(bh)->size) + tmp);
+                affs_fix_checksum(sb, bh);
+                mark_buffer_dirty_inode(bh, inode);
+                written += tmp;
+                from += tmp;
+                bidx++;
+        } else if (bidx) {
+                bh = affs_bread_ino(inode, bidx - 1, 0);
+                if (IS_ERR(bh))
+                        return PTR_ERR(bh);
+        }
+        while (from + bsize <= to) {
+                prev_bh = bh;
+                bh = affs_getemptyblk_ino(inode, bidx);
+                if (IS_ERR(bh))
+                        goto out;
+                memcpy(AFFS_DATA(bh), data + from, bsize);
+                if (buffer_new(bh)) {
+                        AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
+                        AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
+                        AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
+                        AFFS_DATA_HEAD(bh)->size = cpu_to_be32(bsize);
+                        AFFS_DATA_HEAD(bh)->next = 0;
+                        bh->b_state &= ~(1UL << BH_New);
+                        if (prev_bh) {
+                                u32 tmp = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
+                                if (tmp)
+                                        affs_warning(sb, "commit_write_ofs", "next block already set for %d (%d)", bidx, tmp);
+                                AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
+                                affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp);
+                                mark_buffer_dirty_inode(prev_bh, inode);
+                        }
+                }
+                affs_brelse(prev_bh);
+                affs_fix_checksum(sb, bh);
+                mark_buffer_dirty_inode(bh, inode);
+                written += bsize;
+                from += bsize;
+                bidx++;
+        }
+        if (from < to) {
+                prev_bh = bh;
+                bh = affs_bread_ino(inode, bidx, 1);
+                if (IS_ERR(bh))
+                        goto out;
+                tmp = min(bsize, to - from);
+                if (tmp > bsize)
+                        BUG();
+                memcpy(AFFS_DATA(bh), data + from, tmp);
+                if (buffer_new(bh)) {
+                        AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
+                        AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
+                        AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
+                        AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
+                        AFFS_DATA_HEAD(bh)->next = 0;
+                        bh->b_state &= ~(1UL << BH_New);
+                        if (prev_bh) {
+                                u32 tmp = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
+                                if (tmp)
+                                        affs_warning(sb, "commit_write_ofs", "next block already set for %d (%d)", bidx, tmp);
+                                AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
+                                affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp);
+                                mark_buffer_dirty_inode(prev_bh, inode);
+                        }
+                } else if (be32_to_cpu(AFFS_DATA_HEAD(bh)->size) < tmp)
+                        AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
+                affs_brelse(prev_bh);
+                affs_fix_checksum(sb, bh);
+                mark_buffer_dirty_inode(bh, inode);
+                written += tmp;
+                from += tmp;
+                bidx++;
+        }
+        SetPageUptodate(page);
+
+done:
+        affs_brelse(bh);
+        tmp = (page->index << PAGE_CACHE_SHIFT) + from;
+        if (tmp > inode->i_size)
+                inode->i_size = AFFS_I(inode)->mmu_private = tmp;
+
+        return written;
+
+out:
+        bh = prev_bh;
+        if (!written)
+                written = PTR_ERR(bh);
+        goto done;
+}
+
+struct address_space_operations affs_aops_ofs = {
+        .readpage = affs_readpage_ofs,
+        //.writepage = affs_writepage_ofs,
+        //.sync_page = affs_sync_page_ofs,
+        .prepare_write = affs_prepare_write_ofs,
+        .commit_write = affs_commit_write_ofs
+};
+
+/* Free any preallocated blocks. */
+
+void
+affs_free_prealloc(struct inode *inode)
+{
+        struct super_block *sb = inode->i_sb;
+
+        pr_debug("AFFS: free_prealloc(ino=%lu)\n", inode->i_ino);
+
+        while (AFFS_I(inode)->i_pa_cnt) {
+                AFFS_I(inode)->i_pa_cnt--;
+                affs_free_block(sb, ++AFFS_I(inode)->i_lastalloc);
+        }
+}
+
+/* Truncate (or enlarge) a file to the requested size. */
+
+void
+affs_truncate(struct inode *inode)
+{
+        struct super_block *sb = inode->i_sb;
+        u32 ext, ext_key;
+        u32 last_blk, blkcnt, blk;
+        u32 size;
+        struct buffer_head *ext_bh;
+        int i;
+
+        pr_debug("AFFS: truncate(inode=%d, oldsize=%u, newsize=%u)\n",
+                 (u32)inode->i_ino, (u32)AFFS_I(inode)->mmu_private, (u32)inode->i_size);
+
+        last_blk = 0;
+        ext = 0;
+        if (inode->i_size) {
+                last_blk = ((u32)inode->i_size - 1) / AFFS_SB(sb)->s_data_blksize;
+                ext = last_blk / AFFS_SB(sb)->s_hashsize;
+        }
+
+        if (inode->i_size > AFFS_I(inode)->mmu_private) {
+                struct address_space *mapping = inode->i_mapping;
+                struct page *page;
+                u32 size = inode->i_size - 1;
+                int res;
+
+                page = grab_cache_page(mapping, size >> PAGE_CACHE_SHIFT);
+                if (!page)
+                        return;
+                size = (size & (PAGE_CACHE_SIZE - 1)) + 1;
+                res = mapping->a_ops->prepare_write(NULL, page, size, size);
+                if (!res)
+                        res = mapping->a_ops->commit_write(NULL, page, size, size);
+                unlock_page(page);
+                page_cache_release(page);
+                mark_inode_dirty(inode);
+                return;
+        } else if (inode->i_size == AFFS_I(inode)->mmu_private)
+                return;
+
+        // lock cache
+        ext_bh = affs_get_extblock(inode, ext);
+        if (IS_ERR(ext_bh)) {
+                affs_warning(sb, "truncate", "unexpected read error for ext block %u (%d)",
+                             ext, PTR_ERR(ext_bh));
+                return;
+        }
+        if (AFFS_I(inode)->i_lc) {
+                /* clear linear cache */
+                i = (ext + 1) >> AFFS_I(inode)->i_lc_shift;
+                if (AFFS_I(inode)->i_lc_size > i) {
+                        AFFS_I(inode)->i_lc_size = i;
+                        for (; i < AFFS_LC_SIZE; i++)
+                                AFFS_I(inode)->i_lc[i] = 0;
+                }
+                /* clear associative cache */
+                for (i = 0; i < AFFS_AC_SIZE; i++)
+                        if (AFFS_I(inode)->i_ac[i].ext >= ext)
+                                AFFS_I(inode)->i_ac[i].ext = 0;
+        }
+        ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
+
+        blkcnt = AFFS_I(inode)->i_blkcnt;
+        i = 0;
+        blk = last_blk;
+        if (inode->i_size) {
+                i = last_blk % AFFS_SB(sb)->s_hashsize + 1;
+                blk++;
+        } else
+                AFFS_HEAD(ext_bh)->first_data = 0;
+        size = AFFS_SB(sb)->s_hashsize;
+        if (size > blkcnt - blk + i)
+                size = blkcnt - blk + i;
+        for (; i < size; i++, blk++) {
+                affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
+                AFFS_BLOCK(sb, ext_bh, i) = 0;
+        }
+        AFFS_TAIL(sb, ext_bh)->extension = 0;
+        affs_fix_checksum(sb, ext_bh);
+        mark_buffer_dirty_inode(ext_bh, inode);
+        affs_brelse(ext_bh);
+
+        if (inode->i_size) {
+                AFFS_I(inode)->i_blkcnt = last_blk + 1;
+                AFFS_I(inode)->i_extcnt = ext + 1;
+                if (AFFS_SB(sb)->s_flags & SF_OFS) {
+                        struct buffer_head *bh = affs_bread_ino(inode, last_blk, 0);
+                        u32 tmp;
+                        if (IS_ERR(ext_bh)) {
+                                affs_warning(sb, "truncate", "unexpected read error for last block %u (%d)",
+                                             ext, PTR_ERR(ext_bh));
+                                return;
+                        }
+                        tmp = be32_to_cpu(AFFS_DATA_HEAD(bh)->next);
+                        AFFS_DATA_HEAD(bh)->next = 0;
+                        affs_adjust_checksum(bh, -tmp);
+                        affs_brelse(bh);
+                }
+        } else {
+                AFFS_I(inode)->i_blkcnt = 0;
+                AFFS_I(inode)->i_extcnt = 1;
+        }
+        AFFS_I(inode)->mmu_private = inode->i_size;
+        // unlock cache
+
+        while (ext_key) {
+                ext_bh = affs_bread(sb, ext_key);
+                size = AFFS_SB(sb)->s_hashsize;
+                if (size > blkcnt - blk)
+                        size = blkcnt - blk;
+                for (i = 0; i < size; i++, blk++)
+                        affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
+                affs_free_block(sb, ext_key);
+                ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
+                affs_brelse(ext_bh);
+        }
+        affs_free_prealloc(inode);
+}