From: Akira Fujita Subject: [PATCH 1/2]ext4: Fix exchanged block count in EXT4_IOC_MOVE_EXT failure Date: Fri, 02 Oct 2009 17:24:37 +0900 Message-ID: <4AC5B8C5.8000205@rs.jp.nec.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit To: Theodore Tso , linux-ext4@vger.kernel.org Return-path: Received: from TYO201.gate.nec.co.jp ([202.32.8.193]:53630 "EHLO tyo201.gate.nec.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753395AbZJBIZQ (ORCPT ); Fri, 2 Oct 2009 04:25:16 -0400 Sender: linux-ext4-owner@vger.kernel.org List-ID: ext4: Fix block count in EXT4_IOC_MOVE_EXT failure From: Akira Fujita The halfway exchanged block count should be returned to the user-space, if EXT4_IOC_MOVE_EXT is failed for some reasons in the environment where block size is not same as page size. But current EXT4_IOC_MOVE_EXT returns page-aligned block count to the user-space. The patch fixes this issue. Signed-off-by: Akira Fujita --- fs/ext4/move_extent.c | 139 ++++++++++++++++++++++++++----------------------- 1 files changed, 73 insertions(+), 66 deletions(-) diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c index 25b6b14..83f8c9e 100644 --- a/fs/ext4/move_extent.c +++ b/fs/ext4/move_extent.c @@ -661,6 +661,7 @@ mext_calc_swap_extents(struct ext4_extent *tmp_dext, * @donor_inode: donor inode * @from: block offset of orig_inode * @count: block count to be replaced + * @err: pointer to save return value * * Replace original inode extents and donor inode extents page by page. * We implement this replacement in the following three steps: @@ -671,19 +672,18 @@ mext_calc_swap_extents(struct ext4_extent *tmp_dext, * 3. Change the block information of donor inode to point at the saved * original inode blocks in the dummy extents. * - * Return 0 on success, or a negative error value on failure. + * Return replaced block count. */ static int mext_replace_branches(handle_t *handle, struct inode *orig_inode, struct inode *donor_inode, ext4_lblk_t from, - ext4_lblk_t count) + ext4_lblk_t count, int *err) { struct ext4_ext_path *orig_path = NULL; struct ext4_ext_path *donor_path = NULL; struct ext4_extent *oext, *dext; struct ext4_extent tmp_dext, tmp_oext; ext4_lblk_t orig_off = from, donor_off = from; - int err = 0; int depth; int replaced_count = 0; int dext_alen; @@ -691,13 +691,13 @@ mext_replace_branches(handle_t *handle, struct inode *orig_inode, mext_double_down_write(orig_inode, donor_inode); /* Get the original extent for the block "orig_off" */ - err = get_ext_path(orig_inode, orig_off, &orig_path); - if (err) + *err = get_ext_path(orig_inode, orig_off, &orig_path); + if (*err) goto out; /* Get the donor extent for the head */ - err = get_ext_path(donor_inode, donor_off, &donor_path); - if (err) + *err = get_ext_path(donor_inode, donor_off, &donor_path); + if (*err) goto out; depth = ext_depth(orig_inode); oext = orig_path[depth].p_ext; @@ -707,9 +707,9 @@ mext_replace_branches(handle_t *handle, struct inode *orig_inode, dext = donor_path[depth].p_ext; tmp_dext = *dext; - err = mext_calc_swap_extents(&tmp_dext, &tmp_oext, orig_off, + *err = mext_calc_swap_extents(&tmp_dext, &tmp_oext, orig_off, donor_off, count); - if (err) + if (*err) goto out; /* Loop for the donor extents */ @@ -718,7 +718,7 @@ mext_replace_branches(handle_t *handle, struct inode *orig_inode, if (!dext) { ext4_error(donor_inode->i_sb, __func__, "The extent for donor must be found"); - err = -EIO; + *err = -EIO; goto out; } else if (donor_off != le32_to_cpu(tmp_dext.ee_block)) { ext4_error(donor_inode->i_sb, __func__, @@ -726,20 +726,20 @@ mext_replace_branches(handle_t *handle, struct inode *orig_inode, "extent(%u) should be equal", donor_off, le32_to_cpu(tmp_dext.ee_block)); - err = -EIO; + *err = -EIO; goto out; } /* Set donor extent to orig extent */ - err = mext_leaf_block(handle, orig_inode, + *err = mext_leaf_block(handle, orig_inode, orig_path, &tmp_dext, &orig_off); - if (err < 0) + if (*err) goto out; /* Set orig extent to donor extent */ - err = mext_leaf_block(handle, donor_inode, + *err = mext_leaf_block(handle, donor_inode, donor_path, &tmp_oext, &donor_off); - if (err < 0) + if (*err) goto out; dext_alen = ext4_ext_get_actual_len(&tmp_dext); @@ -753,35 +753,25 @@ mext_replace_branches(handle_t *handle, struct inode *orig_inode, if (orig_path) ext4_ext_drop_refs(orig_path); - err = get_ext_path(orig_inode, orig_off, &orig_path); - if (err) + *err = get_ext_path(orig_inode, orig_off, &orig_path); + if (*err) goto out; depth = ext_depth(orig_inode); oext = orig_path[depth].p_ext; - if (le32_to_cpu(oext->ee_block) + - ext4_ext_get_actual_len(oext) <= orig_off) { - err = 0; - goto out; - } tmp_oext = *oext; if (donor_path) ext4_ext_drop_refs(donor_path); - err = get_ext_path(donor_inode, donor_off, &donor_path); - if (err) + *err = get_ext_path(donor_inode, donor_off, &donor_path); + if (*err) goto out; depth = ext_depth(donor_inode); dext = donor_path[depth].p_ext; - if (le32_to_cpu(dext->ee_block) + - ext4_ext_get_actual_len(dext) <= donor_off) { - err = 0; - goto out; - } tmp_dext = *dext; - err = mext_calc_swap_extents(&tmp_dext, &tmp_oext, orig_off, + *err = mext_calc_swap_extents(&tmp_dext, &tmp_oext, orig_off, donor_off, count - replaced_count); - if (err) + if (*err) goto out; } @@ -796,7 +786,7 @@ out: } mext_double_up_write(orig_inode, donor_inode); - return err; + return replaced_count; } /** @@ -808,16 +798,17 @@ out: * @data_offset_in_page: block index where data swapping starts * @block_len_in_page: the number of blocks to be swapped * @uninit: orig extent is uninitialized or not + * @err: pointer to save return value * * Save the data in original inode blocks and replace original inode extents * with donor inode extents by calling mext_replace_branches(). - * Finally, write out the saved data in new original inode blocks. Return 0 - * on success, or a negative error value on failure. + * Finally, write out the saved data in new original inode blocks. Return + * replaced block count. */ static int move_extent_per_page(struct file *o_filp, struct inode *donor_inode, pgoff_t orig_page_offset, int data_offset_in_page, - int block_len_in_page, int uninit) + int block_len_in_page, int uninit, int *err) { struct inode *orig_inode = o_filp->f_dentry->d_inode; struct address_space *mapping = orig_inode->i_mapping; @@ -829,9 +820,11 @@ move_extent_per_page(struct file *o_filp, struct inode *donor_inode, long long offs = orig_page_offset << PAGE_CACHE_SHIFT; unsigned long blocksize = orig_inode->i_sb->s_blocksize; unsigned int w_flags = 0; - unsigned int tmp_data_len, data_len; + unsigned int tmp_data_size, data_size, replaced_size; void *fsdata; - int ret, i, jblocks; + int i, jblocks; + int err2 = 0; + int replaced_count = 0; int blocks_per_page = PAGE_CACHE_SIZE >> orig_inode->i_blkbits; /* @@ -841,8 +834,8 @@ move_extent_per_page(struct file *o_filp, struct inode *donor_inode, jblocks = ext4_writepage_trans_blocks(orig_inode) * 2; handle = ext4_journal_start(orig_inode, jblocks); if (IS_ERR(handle)) { - ret = PTR_ERR(handle); - return ret; + *err = PTR_ERR(handle); + return 0; } if (segment_eq(get_fs(), KERNEL_DS)) @@ -858,9 +851,9 @@ move_extent_per_page(struct file *o_filp, struct inode *donor_inode, * Just swap data blocks between orig and donor. */ if (uninit) { - ret = mext_replace_branches(handle, orig_inode, - donor_inode, orig_blk_offset, - block_len_in_page); + replaced_count = mext_replace_branches(handle, orig_inode, + donor_inode, orig_blk_offset, + block_len_in_page, err); /* Clear the inode cache not to refer to the old data */ ext4_ext_invalidate_cache(orig_inode); @@ -870,27 +863,28 @@ move_extent_per_page(struct file *o_filp, struct inode *donor_inode, offs = (long long)orig_blk_offset << orig_inode->i_blkbits; - /* Calculate data_len */ + /* Calculate data_size */ if ((orig_blk_offset + block_len_in_page - 1) == ((orig_inode->i_size - 1) >> orig_inode->i_blkbits)) { /* Replace the last block */ - tmp_data_len = orig_inode->i_size & (blocksize - 1); + tmp_data_size = orig_inode->i_size & (blocksize - 1); /* - * If data_len equal zero, it shows data_len is multiples of + * If data_size equal zero, it shows data_size is multiples of * blocksize. So we set appropriate value. */ - if (tmp_data_len == 0) - tmp_data_len = blocksize; + if (tmp_data_size == 0) + tmp_data_size = blocksize; - data_len = tmp_data_len + + data_size = tmp_data_size + ((block_len_in_page - 1) << orig_inode->i_blkbits); - } else { - data_len = block_len_in_page << orig_inode->i_blkbits; - } + } else + data_size = block_len_in_page << orig_inode->i_blkbits; + + replaced_size = data_size; - ret = a_ops->write_begin(o_filp, mapping, offs, data_len, w_flags, + *err = a_ops->write_begin(o_filp, mapping, offs, data_size, w_flags, &page, &fsdata); - if (unlikely(ret < 0)) + if (unlikely(*err < 0)) goto out; if (!PageUptodate(page)) { @@ -911,10 +905,17 @@ move_extent_per_page(struct file *o_filp, struct inode *donor_inode, /* Release old bh and drop refs */ try_to_release_page(page, 0); - ret = mext_replace_branches(handle, orig_inode, donor_inode, - orig_blk_offset, block_len_in_page); - if (ret < 0) - goto out; + replaced_count = mext_replace_branches(handle, orig_inode, donor_inode, + orig_blk_offset, block_len_in_page, + &err2); + if (err2) { + if (replaced_count) { + block_len_in_page = replaced_count; + replaced_size = + block_len_in_page << orig_inode->i_blkbits; + } else + goto out; + } /* Clear the inode cache not to refer to the old data */ ext4_ext_invalidate_cache(orig_inode); @@ -928,16 +929,16 @@ move_extent_per_page(struct file *o_filp, struct inode *donor_inode, bh = bh->b_this_page; for (i = 0; i < block_len_in_page; i++) { - ret = ext4_get_block(orig_inode, + *err = ext4_get_block(orig_inode, (sector_t)(orig_blk_offset + i), bh, 0); - if (ret < 0) + if (*err < 0) goto out; if (bh->b_this_page != NULL) bh = bh->b_this_page; } - ret = a_ops->write_end(o_filp, mapping, offs, data_len, data_len, + *err = a_ops->write_end(o_filp, mapping, offs, data_size, replaced_size, page, fsdata); page = NULL; @@ -951,7 +952,10 @@ out: out2: ext4_journal_stop(handle); - return ret < 0 ? ret : 0; + if (err2) + *err = err2; + + return replaced_count; } /** @@ -1367,15 +1371,17 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp, while (orig_page_offset <= seq_end_page) { /* Swap original branches with new branches */ - ret1 = move_extent_per_page(o_filp, donor_inode, + block_len_in_page = move_extent_per_page( + o_filp, donor_inode, orig_page_offset, data_offset_in_page, - block_len_in_page, uninit); - if (ret1 < 0) - goto out; - orig_page_offset++; + block_len_in_page, uninit, + &ret1); + /* Count how many blocks we have exchanged */ *moved_len += block_len_in_page; + if (ret1 < 0) + goto out; if (*moved_len > len) { ext4_error(orig_inode->i_sb, __func__, "We replaced blocks too much! " @@ -1385,6 +1391,7 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp, goto out; } + orig_page_offset++; data_offset_in_page = 0; rest_blocks -= block_len_in_page; if (rest_blocks > blocks_per_page)