/* * Copyright IBM Corporation, 2007 * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> * * This program is free software; you can redistribute it and/or modify it * under the terms of version 2.1 of the GNU Lesser General Public License * as published by the Free Software Foundation. * * This program is distributed in the hope that it would be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. * */ #include <linux/module.h> #include "ext4_jbd2.h" #include "ext4_extents.h" /* * The contiguous blocks details which can be * represented by a single extent */ struct list_blocks_struct { ext4_lblk_t first_block, last_block; ext4_fsblk_t first_pblock, last_pblock; }; static int finish_range(handle_t *handle, struct inode *inode, struct list_blocks_struct *lb) { int retval = 0, needed; struct ext4_extent newext; struct ext4_ext_path *path; if (lb->first_pblock == 0) return 0; /* Add the extent to temp inode*/ newext.ee_block = cpu_to_le32(lb->first_block); newext.ee_len = cpu_to_le16(lb->last_block - lb->first_block + 1); ext4_ext_store_pblock(&newext, lb->first_pblock); path = ext4_ext_find_extent(inode, lb->first_block, NULL); if (IS_ERR(path)) { retval = PTR_ERR(path); path = NULL; goto err_out; } /* * Calculate the credit needed to inserting this extent * Since we are doing this in loop we may accumalate extra * credit. But below we try to not accumalate too much * of them by restarting the journal. */ needed = ext4_ext_calc_credits_for_insert(inode, path); /* * Make sure the credit we accumalated is not really high */ if (needed && handle->h_buffer_credits >= EXT4_RESERVE_TRANS_BLOCKS) { retval = ext4_journal_restart(handle, needed); if (retval) goto err_out; } else if (needed) { retval = ext4_journal_extend(handle, needed); if (retval) { /* * IF not able to extend the journal restart the journal */ retval = ext4_journal_restart(handle, needed); if (retval) goto err_out; } } retval = ext4_ext_insert_extent(handle, inode, path, &newext); err_out: if (path) { ext4_ext_drop_refs(path); kfree(path); } lb->first_pblock = 0; return retval; } static int update_extent_range(handle_t *handle, struct inode *inode, ext4_fsblk_t pblock, ext4_lblk_t blk_num, struct list_blocks_struct *lb) { int retval; /* * See if we can add on to the existing range (if it exists) */ if (lb->first_pblock && (lb->last_pblock+1 == pblock) && (lb->last_block+1 == blk_num)) { lb->last_pblock = pblock; lb->last_block = blk_num; return 0; } /* * Start a new range. */ retval = finish_range(handle, inode, lb); lb->first_pblock = lb->last_pblock = pblock; lb->first_block = lb->last_block = blk_num; return retval; } static int update_ind_extent_range(handle_t *handle, struct inode *inode, ext4_fsblk_t pblock, ext4_lblk_t *blk_nump, struct list_blocks_struct *lb) { struct buffer_head *bh; __le32 *i_data; int i, retval = 0; ext4_lblk_t blk_count = *blk_nump; unsigned long max_entries = inode->i_sb->s_blocksize >> 2; if (!pblock) { /* Only update the file block number */ *blk_nump += max_entries; return 0; } bh = sb_bread(inode->i_sb, pblock); if (!bh) return -EIO; i_data = (__le32 *)bh->b_data; for (i = 0; i < max_entries; i++, blk_count++) { if (i_data[i]) { retval = update_extent_range(handle, inode, le32_to_cpu(i_data[i]), blk_count, lb); if (retval) break; } } /* Update the file block number */ *blk_nump = blk_count; put_bh(bh); return retval; } static int update_dind_extent_range(handle_t *handle, struct inode *inode, ext4_fsblk_t pblock, ext4_lblk_t *blk_nump, struct list_blocks_struct *lb) { struct buffer_head *bh; __le32 *i_data; int i, retval = 0; ext4_lblk_t blk_count = *blk_nump; unsigned long max_entries = inode->i_sb->s_blocksize >> 2; if (!pblock) { /* Only update the file block number */ *blk_nump += max_entries * max_entries; return 0; } bh = sb_bread(inode->i_sb, pblock); if (!bh) return -EIO; i_data = (__le32 *)bh->b_data; for (i = 0; i < max_entries; i++) { if (i_data[i]) { retval = update_ind_extent_range(handle, inode, le32_to_cpu(i_data[i]), &blk_count, lb); if (retval) break; } else { /* Only update the file block number */ blk_count += max_entries; } } /* Update the file block number */ *blk_nump = blk_count; put_bh(bh); return retval; } static int update_tind_extent_range(handle_t *handle, struct inode *inode, ext4_fsblk_t pblock, ext4_lblk_t *blk_nump, struct list_blocks_struct *lb) { struct buffer_head *bh; __le32 *i_data; int i, retval = 0; ext4_lblk_t blk_count = *blk_nump; unsigned long max_entries = inode->i_sb->s_blocksize >> 2; if (!pblock) { /* Only update the file block number */ *blk_nump += max_entries * max_entries * max_entries; return 0; } bh = sb_bread(inode->i_sb, pblock); if (!bh) return -EIO; i_data = (__le32 *)bh->b_data; for (i = 0; i < max_entries; i++) { if (i_data[i]) { retval = update_dind_extent_range(handle, inode, le32_to_cpu(i_data[i]), &blk_count, lb); if (retval) break; } else /* Only update the file block number */ blk_count += max_entries * max_entries; } /* Update the file block number */ *blk_nump = blk_count; put_bh(bh); return retval; } static int extend_credit_for_blkdel(handle_t *handle, struct inode *inode) { int retval = 0, needed; if (handle->h_buffer_credits > EXT4_RESERVE_TRANS_BLOCKS) return 0; /* * We are freeing a blocks. During this we touch * superblock, group descriptor and block bitmap. * So allocate a credit of 3. We may update * quota (user and group). */ needed = 3 + 2*EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb); if (ext4_journal_extend(handle, needed) != 0) retval = ext4_journal_restart(handle, needed); return retval; } static int free_dind_blocks(handle_t *handle, struct inode *inode, __le32 i_data) { int i; __le32 *tmp_idata; struct buffer_head *bh; unsigned long max_entries = inode->i_sb->s_blocksize >> 2; bh = sb_bread(inode->i_sb, le32_to_cpu(i_data)); if (!bh) return -EIO; tmp_idata = (__le32 *)bh->b_data; for (i = 0; i < max_entries; i++) { if (tmp_idata[i]) { extend_credit_for_blkdel(handle, inode); ext4_free_blocks(handle, inode, le32_to_cpu(tmp_idata[i]), 1, 1); } } put_bh(bh); extend_credit_for_blkdel(handle, inode); ext4_free_blocks(handle, inode, le32_to_cpu(i_data), 1, 1); return 0; } static int free_tind_blocks(handle_t *handle, struct inode *inode, __le32 i_data) { int i, retval = 0; __le32 *tmp_idata; struct buffer_head *bh; unsigned long max_entries = inode->i_sb->s_blocksize >> 2; bh = sb_bread(inode->i_sb, le32_to_cpu(i_data)); if (!bh) return -EIO; tmp_idata = (__le32 *)bh->b_data; for (i = 0; i < max_entries; i++) { if (tmp_idata[i]) { retval = free_dind_blocks(handle, inode, tmp_idata[i]); if (retval) { put_bh(bh); return retval; } } } put_bh(bh); extend_credit_for_blkdel(handle, inode); ext4_free_blocks(handle, inode, le32_to_cpu(i_data), 1, 1); return 0; } static int free_ind_block(handle_t *handle, struct inode *inode, __le32 *i_data) { int retval; /* ei->i_data[EXT4_IND_BLOCK] */ if (i_data[0]) { extend_credit_for_blkdel(handle, inode); ext4_free_blocks(handle, inode, le32_to_cpu(i_data[0]), 1, 1); } /* ei->i_data[EXT4_DIND_BLOCK] */ if (i_data[1]) { retval = free_dind_blocks(handle, inode, i_data[1]); if (retval) return retval; } /* ei->i_data[EXT4_TIND_BLOCK] */ if (i_data[2]) { retval = free_tind_blocks(handle, inode, i_data[2]); if (retval) return retval; } return 0; } static int ext4_ext_swap_inode_data(handle_t *handle, struct inode *inode, struct inode *tmp_inode) { int retval; __le32 i_data[3]; struct ext4_inode_info *ei = EXT4_I(inode); struct ext4_inode_info *tmp_ei = EXT4_I(tmp_inode); /* * One credit accounted for writing the * i_data field of the original inode */ retval = ext4_journal_extend(handle, 1); if (retval) { retval = ext4_journal_restart(handle, 1); if (retval) goto err_out; } i_data[0] = ei->i_data[EXT4_IND_BLOCK]; i_data[1] = ei->i_data[EXT4_DIND_BLOCK]; i_data[2] = ei->i_data[EXT4_TIND_BLOCK]; down_write(&EXT4_I(inode)->i_data_sem); /* * if EXT4_EXT_MIGRATE is cleared a block allocation * happened after we started the migrate. We need to * fail the migrate */ if (!(EXT4_I(inode)->i_flags & EXT4_EXT_MIGRATE)) { retval = -EAGAIN; up_write(&EXT4_I(inode)->i_data_sem); goto err_out; } else EXT4_I(inode)->i_flags = EXT4_I(inode)->i_flags & ~EXT4_EXT_MIGRATE; /* * We have the extent map build with the tmp inode. * Now copy the i_data across */ ei->i_flags |= EXT4_EXTENTS_FL; memcpy(ei->i_data, tmp_ei->i_data, sizeof(ei->i_data)); /* * Update i_blocks with the new blocks that got * allocated while adding extents for extent index * blocks. * * While converting to extents we need not * update the orignal inode i_blocks for extent blocks * via quota APIs. The quota update happened via tmp_inode already. */ spin_lock(&inode->i_lock); inode->i_blocks += tmp_inode->i_blocks; spin_unlock(&inode->i_lock); up_write(&EXT4_I(inode)->i_data_sem); /* * We mark the inode dirty after, because we decrement the * i_blocks when freeing the indirect meta-data blocks */ retval = free_ind_block(handle, inode, i_data); ext4_mark_inode_dirty(handle, inode); err_out: return retval; } static int free_ext_idx(handle_t *handle, struct inode *inode, struct ext4_extent_idx *ix) { int i, retval = 0; ext4_fsblk_t block; struct buffer_head *bh; struct ext4_extent_header *eh; block = idx_pblock(ix); bh = sb_bread(inode->i_sb, block); if (!bh) return -EIO; eh = (struct ext4_extent_header *)bh->b_data; if (eh->eh_depth != 0) { ix = EXT_FIRST_INDEX(eh); for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ix++) { retval = free_ext_idx(handle, inode, ix); if (retval) break; } } put_bh(bh); extend_credit_for_blkdel(handle, inode); ext4_free_blocks(handle, inode, block, 1, 1); return retval; } /* * Free the extent meta data blocks only */ static int free_ext_block(handle_t *handle, struct inode *inode) { int i, retval = 0; struct ext4_inode_info *ei = EXT4_I(inode); struct ext4_extent_header *eh = (struct ext4_extent_header *)ei->i_data; struct ext4_extent_idx *ix; if (eh->eh_depth == 0) /* * No extra blocks allocated for extent meta data */ return 0; ix = EXT_FIRST_INDEX(eh); for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ix++) { retval = free_ext_idx(handle, inode, ix); if (retval) return retval; } return retval; } int ext4_ext_migrate(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg) { handle_t *handle; int retval = 0, i; __le32 *i_data; ext4_lblk_t blk_count = 0; struct ext4_inode_info *ei; struct inode *tmp_inode = NULL; struct list_blocks_struct lb; unsigned long max_entries; if (!test_opt(inode->i_sb, EXTENTS)) /* * if mounted with noextents we don't allow the migrate */ return -EINVAL; if ((EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)) return -EINVAL; if (S_ISLNK(inode->i_mode) && inode->i_blocks == 0) /* * don't migrate fast symlink */ return retval; handle = ext4_journal_start(inode, EXT4_DATA_TRANS_BLOCKS(inode->i_sb) + EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 + 2 * EXT4_QUOTA_INIT_BLOCKS(inode->i_sb) + 1); if (IS_ERR(handle)) { retval = PTR_ERR(handle); goto err_out; } tmp_inode = ext4_new_inode(handle, inode->i_sb->s_root->d_inode, S_IFREG); if (IS_ERR(tmp_inode)) { retval = -ENOMEM; ext4_journal_stop(handle); tmp_inode = NULL; goto err_out; } i_size_write(tmp_inode, i_size_read(inode)); /* * We don't want the inode to be reclaimed * if we got interrupted in between. We have * this tmp inode carrying reference to the * data blocks of the original file. We set * the i_nlink to zero at the last stage after * switching the original file to extent format */ tmp_inode->i_nlink = 1; ext4_ext_tree_init(handle, tmp_inode); ext4_orphan_add(handle, tmp_inode); ext4_journal_stop(handle); /* * start with one credit accounted for * superblock modification. * * For the tmp_inode we already have commited the * trascation that created the inode. Later as and * when we add extents we extent the journal */ /* * inode_mutex prevent write and truncate on the file. Read still goes * through. We take i_data_sem in ext4_ext_swap_inode_data before we * switch the inode format to prevent read. */ mutex_lock(&(inode->i_mutex)); /* * Even though we take i_mutex we can still cause block allocation * via mmap write to holes. If we have allocated new blocks we fail * migrate. New block allocation will clear EXT4_EXT_MIGRATE flag. * The flag is updated with i_data_sem held to prevent racing with * block allocation. */ down_read((&EXT4_I(inode)->i_data_sem)); EXT4_I(inode)->i_flags = EXT4_I(inode)->i_flags | EXT4_EXT_MIGRATE; up_read((&EXT4_I(inode)->i_data_sem)); handle = ext4_journal_start(inode, 1); ei = EXT4_I(inode); i_data = ei->i_data; memset(&lb, 0, sizeof(lb)); /* 32 bit block address 4 bytes */ max_entries = inode->i_sb->s_blocksize >> 2; for (i = 0; i < EXT4_NDIR_BLOCKS; i++, blk_count++) { if (i_data[i]) { retval = update_extent_range(handle, tmp_inode, le32_to_cpu(i_data[i]), blk_count, &lb); if (retval) goto err_out; } } if (i_data[EXT4_IND_BLOCK]) { retval = update_ind_extent_range(handle, tmp_inode, le32_to_cpu(i_data[EXT4_IND_BLOCK]), &blk_count, &lb); if (retval) goto err_out; } else blk_count += max_entries; if (i_data[EXT4_DIND_BLOCK]) { retval = update_dind_extent_range(handle, tmp_inode, le32_to_cpu(i_data[EXT4_DIND_BLOCK]), &blk_count, &lb); if (retval) goto err_out; } else blk_count += max_entries * max_entries; if (i_data[EXT4_TIND_BLOCK]) { retval = update_tind_extent_range(handle, tmp_inode, le32_to_cpu(i_data[EXT4_TIND_BLOCK]), &blk_count, &lb); if (retval) goto err_out; } /* * Build the last extent */ retval = finish_range(handle, tmp_inode, &lb); err_out: if (retval) /* * Failure case delete the extent information with the * tmp_inode */ free_ext_block(handle, tmp_inode); else { retval = ext4_ext_swap_inode_data(handle, inode, tmp_inode); if (retval) /* * if we fail to swap inode data free the extent * details of the tmp inode */ free_ext_block(handle, tmp_inode); } /* We mark the tmp_inode dirty via ext4_ext_tree_init. */ if (ext4_journal_extend(handle, 1) != 0) ext4_journal_restart(handle, 1); /* * Mark the tmp_inode as of size zero */ i_size_write(tmp_inode, 0); /* * set the i_blocks count to zero * so that the ext4_delete_inode does the * right job * * We don't need to take the i_lock because * the inode is not visible to user space. */ tmp_inode->i_blocks = 0; /* Reset the extent details */ ext4_ext_tree_init(handle, tmp_inode); /* * Set the i_nlink to zero so that * generic_drop_inode really deletes the * inode */ tmp_inode->i_nlink = 0; ext4_journal_stop(handle); mutex_unlock(&(inode->i_mutex)); if (tmp_inode) iput(tmp_inode); return retval; }