| /* |
| * 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 int affs_file_open(struct inode *inode, struct file *filp); |
| static int affs_file_release(struct inode *inode, struct file *filp); |
| |
| const struct file_operations affs_file_operations = { |
| .llseek = generic_file_llseek, |
| .read = do_sync_read, |
| .aio_read = generic_file_aio_read, |
| .write = do_sync_write, |
| .aio_write = generic_file_aio_write, |
| .mmap = generic_file_mmap, |
| .open = affs_file_open, |
| .release = affs_file_release, |
| .fsync = file_fsync, |
| .splice_read = generic_file_splice_read, |
| }; |
| |
| const 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_write_begin(struct file *file, struct address_space *mapping, |
| loff_t pos, unsigned len, unsigned flags, |
| struct page **pagep, void **fsdata) |
| { |
| *pagep = NULL; |
| return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata, |
| affs_get_block, |
| &AFFS_I(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); |
| } |
| |
| const struct address_space_operations affs_aops = { |
| .readpage = affs_readpage, |
| .writepage = affs_writepage, |
| .sync_page = block_sync_page, |
| .write_begin = affs_write_begin, |
| .write_end = generic_write_end, |
| .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 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_write_begin_ofs(struct file *file, struct address_space *mapping, |
| loff_t pos, unsigned len, unsigned flags, |
| struct page **pagep, void **fsdata) |
| { |
| struct inode *inode = mapping->host; |
| struct page *page; |
| pgoff_t index; |
| int err = 0; |
| |
| pr_debug("AFFS: write_begin(%u, %llu, %llu)\n", (u32)inode->i_ino, (unsigned long long)pos, (unsigned long long)pos + len); |
| if (pos > AFFS_I(inode)->mmu_private) { |
| /* XXX: this probably leaves a too-big i_size in case of |
| * failure. Should really be updating i_size at write_end time |
| */ |
| err = affs_extent_file_ofs(inode, pos); |
| if (err) |
| return err; |
| } |
| |
| index = pos >> PAGE_CACHE_SHIFT; |
| page = __grab_cache_page(mapping, index); |
| if (!page) |
| return -ENOMEM; |
| *pagep = page; |
| |
| if (PageUptodate(page)) |
| return 0; |
| |
| /* XXX: inefficient but safe in the face of short writes */ |
| err = affs_do_readpage_ofs(file, page, 0, PAGE_CACHE_SIZE); |
| if (err) { |
| unlock_page(page); |
| page_cache_release(page); |
| } |
| return err; |
| } |
| |
| static int affs_write_end_ofs(struct file *file, struct address_space *mapping, |
| loff_t pos, unsigned len, unsigned copied, |
| struct page *page, void *fsdata) |
| { |
| struct inode *inode = mapping->host; |
| struct super_block *sb = inode->i_sb; |
| struct buffer_head *bh, *prev_bh; |
| char *data; |
| u32 bidx, boff, bsize; |
| unsigned from, to; |
| u32 tmp; |
| int written; |
| |
| from = pos & (PAGE_CACHE_SIZE - 1); |
| to = pos + len; |
| /* |
| * XXX: not sure if this can handle short copies (len < copied), but |
| * we don't have to, because the page should always be uptodate here, |
| * due to write_begin. |
| */ |
| |
| pr_debug("AFFS: write_begin(%u, %llu, %llu)\n", (u32)inode->i_ino, (unsigned long long)pos, (unsigned long long)pos + len); |
| 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; |
| |
| unlock_page(page); |
| page_cache_release(page); |
| |
| return written; |
| |
| out: |
| bh = prev_bh; |
| if (!written) |
| written = PTR_ERR(bh); |
| goto done; |
| } |
| |
| const struct address_space_operations affs_aops_ofs = { |
| .readpage = affs_readpage_ofs, |
| //.writepage = affs_writepage_ofs, |
| //.sync_page = affs_sync_page_ofs, |
| .write_begin = affs_write_begin_ofs, |
| .write_end = affs_write_end_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; |
| void *fsdata; |
| u32 size = inode->i_size; |
| int res; |
| |
| res = mapping->a_ops->write_begin(NULL, mapping, size, 0, 0, &page, &fsdata); |
| if (!res) |
| res = mapping->a_ops->write_end(NULL, mapping, size, 0, 0, page, fsdata); |
| 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); |
| } |