static int update_extent_range(handle_t *handle, struct inode *inode, ext4_fsblk_t pblock, struct migrate_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 == lb->curr_block)) { lb->last_pblock = pblock; lb->last_block = lb->curr_block; lb->curr_block++; 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 = lb->curr_block; lb->curr_block++; return retval; }
// TODO(halcanary): this function is complex enough to need its logic // tested with unit tests. sk_sp<SkPDFArray> SkPDFMakeCIDGlyphWidthsArray(SkGlyphCache* cache, const SkBitSet* subset, uint16_t emSize, int16_t* defaultAdvance) { // Assuming that on average, the ASCII representation of an advance plus // a space is 8 characters and the ASCII representation of a glyph id is 3 // characters, then the following cut offs for using different range types // apply: // The cost of stopping and starting the range is 7 characers // a. Removing 4 0's or don't care's is a win // The cost of stopping and starting the range plus a run is 22 // characters // b. Removing 3 repeating advances is a win // c. Removing 2 repeating advances and 3 don't cares is a win // When not currently in a range the cost of a run over a range is 16 // characaters, so: // d. Removing a leading 0/don't cares is a win because it is omitted // e. Removing 2 repeating advances is a win auto result = sk_make_sp<SkPDFArray>(); int num_glyphs = SkToInt(cache->getGlyphCount()); bool prevRange = false; int16_t lastAdvance = kInvalidAdvance; int repeatedAdvances = 0; int wildCardsInRun = 0; int trailingWildCards = 0; // Limit the loop count to glyph id ranges provided. int lastIndex = num_glyphs; if (subset) { while (!subset->has(lastIndex - 1) && lastIndex > 0) { --lastIndex; } } AdvanceMetric curRange(0); for (int gId = 0; gId <= lastIndex; gId++) { int16_t advance = kInvalidAdvance; if (gId < lastIndex) { if (!subset || 0 == gId || subset->has(gId)) { advance = (int16_t)cache->getGlyphIDAdvance(gId).fAdvanceX; } else { advance = kDontCareAdvance; } } if (advance == lastAdvance) { repeatedAdvances++; trailingWildCards = 0; } else if (advance == kDontCareAdvance) { wildCardsInRun++; trailingWildCards++; } else if (curRange.fAdvance.count() == repeatedAdvances + 1 + wildCardsInRun) { // All in run. if (lastAdvance == 0) { curRange.fStartId = gId; // reset curRange.fAdvance.setCount(0); trailingWildCards = 0; } else if (repeatedAdvances + 1 >= 2 || trailingWildCards >= 4) { finish_range(&curRange, gId - 1, AdvanceMetric::kRun); compose_advance_data(curRange, emSize, defaultAdvance, result.get()); prevRange = true; curRange = AdvanceMetric(gId); trailingWildCards = 0; } repeatedAdvances = 0; wildCardsInRun = trailingWildCards; trailingWildCards = 0; } else { if (lastAdvance == 0 && repeatedAdvances + 1 + wildCardsInRun >= 4) { finish_range(&curRange, gId - repeatedAdvances - wildCardsInRun - 2, AdvanceMetric::kRange); compose_advance_data(curRange, emSize, defaultAdvance, result.get()); prevRange = true; curRange = AdvanceMetric(gId); trailingWildCards = 0; } else if (trailingWildCards >= 4 && repeatedAdvances + 1 < 2) { finish_range(&curRange, gId - trailingWildCards - 1, AdvanceMetric::kRange); compose_advance_data(curRange, emSize, defaultAdvance, result.get()); prevRange = true; curRange = AdvanceMetric(gId); trailingWildCards = 0; } else if (lastAdvance != 0 && (repeatedAdvances + 1 >= 3 || (repeatedAdvances + 1 >= 2 && wildCardsInRun >= 3))) { finish_range(&curRange, gId - repeatedAdvances - wildCardsInRun - 2, AdvanceMetric::kRange); compose_advance_data(curRange, emSize, defaultAdvance, result.get()); curRange = AdvanceMetric(gId - repeatedAdvances - wildCardsInRun - 1); curRange.fAdvance.append(1, &lastAdvance); finish_range(&curRange, gId - 1, AdvanceMetric::kRun); compose_advance_data(curRange, emSize, defaultAdvance, result.get()); prevRange = true; curRange = AdvanceMetric(gId); trailingWildCards = 0; } repeatedAdvances = 0; wildCardsInRun = trailingWildCards; trailingWildCards = 0; } curRange.fAdvance.append(1, &advance); if (advance != kDontCareAdvance) { lastAdvance = advance; } } if (curRange.fStartId == lastIndex) { if (!prevRange) { return nullptr; // https://crbug.com/567031 } } else { finish_range(&curRange, lastIndex - 1, AdvanceMetric::kRange); compose_advance_data(curRange, emSize, defaultAdvance, result.get()); } return result; }
int ext4_ext_migrate(struct inode *inode) { 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; __u32 goal; /* * If the filesystem does not support extents, or the inode * already is extent-based, error out. */ if (!EXT4_HAS_INCOMPAT_FEATURE(inode->i_sb, EXT4_FEATURE_INCOMPAT_EXTENTS) || (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 + EXT4_MAXQUOTAS_INIT_BLOCKS(inode->i_sb) + 1); if (IS_ERR(handle)) { retval = PTR_ERR(handle); return retval; } goal = (((inode->i_ino - 1) / EXT4_INODES_PER_GROUP(inode->i_sb)) * EXT4_INODES_PER_GROUP(inode->i_sb)) + 1; tmp_inode = ext4_new_inode(handle, inode->i_sb->s_root->d_inode, S_IFREG, 0, goal); if (IS_ERR(tmp_inode)) { retval = -ENOMEM; ext4_journal_stop(handle); return retval; } 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 */ /* * 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_STATE_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_state |= EXT4_STATE_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); unlock_new_inode(tmp_inode); iput(tmp_inode); return retval; }
int ext4_ext_migrate(struct inode *inode) { handle_t *handle; int retval = 0, i; __le32 *i_data; struct ext4_inode_info *ei; struct inode *tmp_inode = NULL; struct migrate_struct lb; unsigned long max_entries; __u32 goal; uid_t owner[2]; /* * If the filesystem does not support extents, or the inode * already is extent-based, error out. */ if (!EXT4_HAS_INCOMPAT_FEATURE(inode->i_sb, EXT4_FEATURE_INCOMPAT_EXTENTS) || (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) return -EINVAL; if (S_ISLNK(inode->i_mode) && inode->i_blocks == 0) /* * don't migrate fast symlink */ return retval; /* * Worst case we can touch the allocation bitmaps, a bgd * block, and a block to link in the orphan list. We do need * need to worry about credits for modifying the quota inode. */ handle = ext4_journal_start(inode, EXT4_HT_MIGRATE, 4 + EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb)); if (IS_ERR(handle)) { retval = PTR_ERR(handle); return retval; } goal = (((inode->i_ino - 1) / EXT4_INODES_PER_GROUP(inode->i_sb)) * EXT4_INODES_PER_GROUP(inode->i_sb)) + 1; owner[0] = i_uid_read(inode); owner[1] = i_gid_read(inode); tmp_inode = ext4_new_inode(handle, inode->i_sb->s_root->d_inode, S_IFREG, NULL, goal, owner); if (IS_ERR(tmp_inode)) { retval = PTR_ERR(tmp_inode); ext4_journal_stop(handle); return retval; } i_size_write(tmp_inode, i_size_read(inode)); /* * Set the i_nlink to zero so it will be deleted later * when we drop inode reference. */ clear_nlink(tmp_inode); 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 committed the * trascation that created the inode. Later as and * when we add extents we extent the journal */ /* * 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_STATE_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_set_inode_state(inode, EXT4_STATE_EXT_MIGRATE); up_read((&EXT4_I(inode)->i_data_sem)); handle = ext4_journal_start(inode, EXT4_HT_MIGRATE, 1); if (IS_ERR(handle)) { /* * It is impossible to update on-disk structures without * a handle, so just rollback in-core changes and live other * work to orphan_list_cleanup() */ ext4_orphan_del(NULL, tmp_inode); retval = PTR_ERR(handle); goto out; } 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++) { if (i_data[i]) { retval = update_extent_range(handle, tmp_inode, le32_to_cpu(i_data[i]), &lb); if (retval) goto err_out; } else lb.curr_block++; } if (i_data[EXT4_IND_BLOCK]) { retval = update_ind_extent_range(handle, tmp_inode, le32_to_cpu(i_data[EXT4_IND_BLOCK]), &lb); if (retval) goto err_out; } else lb.curr_block += max_entries; if (i_data[EXT4_DIND_BLOCK]) { retval = update_dind_extent_range(handle, tmp_inode, le32_to_cpu(i_data[EXT4_DIND_BLOCK]), &lb); if (retval) goto err_out; } else lb.curr_block += 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]), &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); ext4_journal_stop(handle); out: unlock_new_inode(tmp_inode); iput(tmp_inode); 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)); 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); /* 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; }