From 10e5dce07e6f8f9cea1b54161a888bb099484f88 Mon Sep 17 00:00:00 2001 From: Evgeniy Dushistov Date: Sat, 1 Jul 2006 04:36:24 -0700 Subject: [PATCH] ufs: truncate should allocate block for last byte This patch fixes buggy behaviour of UFS in such kind of scenario: open(, O_TRUNC...) ftruncate(, 1024) ftruncate(, 0) Such a scenario causes ufs_panic and remount read-only. This happen because of according to specification UFS should always allocate block for last byte, and many parts of our implementation rely on this, but `ufs_truncate' doesn't care about this. To make possible return error code and to know about old size, this patch removes `truncate' from ufs inode_operations and uses `setattr' method to call ufs_truncate. Signed-off-by: Evgeniy Dushistov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ufs/truncate.c | 148 +++++++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 135 insertions(+), 13 deletions(-) (limited to 'fs/ufs/truncate.c') diff --git a/fs/ufs/truncate.c b/fs/ufs/truncate.c index 3c3b301f8701..c9b55872079b 100644 --- a/fs/ufs/truncate.c +++ b/fs/ufs/truncate.c @@ -369,24 +369,97 @@ static int ufs_trunc_tindirect (struct inode * inode) UFSD("EXIT\n"); return retry; } - -void ufs_truncate (struct inode * inode) + +static int ufs_alloc_lastblock(struct inode *inode) { + int err = 0; + struct address_space *mapping = inode->i_mapping; + struct ufs_sb_private_info *uspi = UFS_SB(inode->i_sb)->s_uspi; struct ufs_inode_info *ufsi = UFS_I(inode); - struct super_block * sb; - struct ufs_sb_private_info * uspi; - int retry; + unsigned lastfrag, i, end; + struct page *lastpage; + struct buffer_head *bh; + + lastfrag = (i_size_read(inode) + uspi->s_fsize - 1) >> uspi->s_fshift; + + if (!lastfrag) { + ufsi->i_lastfrag = 0; + goto out; + } + lastfrag--; + + lastpage = ufs_get_locked_page(mapping, lastfrag >> + (PAGE_CACHE_SHIFT - inode->i_blkbits)); + if (IS_ERR(lastpage)) { + err = -EIO; + goto out; + } + + end = lastfrag & ((1 << (PAGE_CACHE_SHIFT - inode->i_blkbits)) - 1); + bh = page_buffers(lastpage); + for (i = 0; i < end; ++i) + bh = bh->b_this_page; + + if (!buffer_mapped(bh)) { + err = ufs_getfrag_block(inode, lastfrag, bh, 1); + + if (unlikely(err)) + goto out_unlock; + + if (buffer_new(bh)) { + clear_buffer_new(bh); + unmap_underlying_metadata(bh->b_bdev, + bh->b_blocknr); + /* + * we do not zeroize fragment, because of + * if it maped to hole, it already contains zeroes + */ + set_buffer_uptodate(bh); + mark_buffer_dirty(bh); + set_page_dirty(lastpage); + } + } +out_unlock: + ufs_put_locked_page(lastpage); +out: + return err; +} + +int ufs_truncate(struct inode *inode, loff_t old_i_size) +{ + struct ufs_inode_info *ufsi = UFS_I(inode); + struct super_block *sb = inode->i_sb; + struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi; + int retry, err = 0; UFSD("ENTER\n"); - sb = inode->i_sb; - uspi = UFS_SB(sb)->s_uspi; - if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))) - return; + if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || + S_ISLNK(inode->i_mode))) + return -EINVAL; if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) - return; + return -EPERM; + + if (inode->i_size > old_i_size) { + /* + * if we expand file we should care about + * allocation of block for last byte first of all + */ + err = ufs_alloc_lastblock(inode); + + if (err) { + i_size_write(inode, old_i_size); + goto out; + } + /* + * go away, because of we expand file, and we do not + * need free blocks, and zeroizes page + */ + lock_kernel(); + goto almost_end; + } - block_truncate_page(inode->i_mapping, inode->i_size, ufs_getfrag_block); + block_truncate_page(inode->i_mapping, inode->i_size, ufs_getfrag_block); lock_kernel(); while (1) { @@ -404,9 +477,58 @@ void ufs_truncate (struct inode * inode) yield(); } + if (inode->i_size < old_i_size) { + /* + * now we should have enough space + * to allocate block for last byte + */ + err = ufs_alloc_lastblock(inode); + if (err) + /* + * looks like all the same - we have no space, + * but we truncate file already + */ + inode->i_size = (ufsi->i_lastfrag - 1) * uspi->s_fsize; + } +almost_end: inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC; - ufsi->i_lastfrag = DIRECT_FRAGMENT; unlock_kernel(); mark_inode_dirty(inode); - UFSD("EXIT\n"); +out: + UFSD("EXIT: err %d\n", err); + return err; } + + +/* + * We don't define our `inode->i_op->truncate', and call it here, + * because of: + * - there is no way to know old size + * - there is no way inform user about error, if it happens in `truncate' + */ +static int ufs_setattr(struct dentry *dentry, struct iattr *attr) +{ + struct inode *inode = dentry->d_inode; + unsigned int ia_valid = attr->ia_valid; + int error; + + error = inode_change_ok(inode, attr); + if (error) + return error; + + if (ia_valid & ATTR_SIZE && + attr->ia_size != i_size_read(inode)) { + loff_t old_i_size = inode->i_size; + error = vmtruncate(inode, attr->ia_size); + if (error) + return error; + error = ufs_truncate(inode, old_i_size); + if (error) + return error; + } + return inode_setattr(inode, attr); +} + +struct inode_operations ufs_file_inode_operations = { + .setattr = ufs_setattr, +}; -- cgit v1.2.2