diff options
Diffstat (limited to 'fs/affs/file.c')
| -rw-r--r-- | fs/affs/file.c | 920 |
1 files changed, 920 insertions, 0 deletions
diff --git a/fs/affs/file.c b/fs/affs/file.c new file mode 100644 index 0000000..6744924 --- /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); +} |
