From 6567e837df07e43bffc08ac40858af8133a007bf Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Mon, 16 Apr 2007 09:22:45 -0400 Subject: [PATCH] Btrfs: early work to file_write in big extents Signed-off-by: Chris Mason --- fs/btrfs/ctree.c | 54 +++++++++++++++++++++ fs/btrfs/ctree.h | 15 ++++++ fs/btrfs/file-item.c | 111 ++++++++++++++++++++++++++++++++++++++++--- fs/btrfs/super.c | 75 ++++++++++++++++++++++------- 4 files changed, 232 insertions(+), 23 deletions(-) diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index e2fc6f0d0243..6b76fd967153 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -1249,6 +1249,60 @@ static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root return ret; } +int btrfs_extend_item(struct btrfs_trans_handle *trans, struct btrfs_root + *root, struct btrfs_path *path, u32 data_size) +{ + int ret = 0; + int slot; + int slot_orig; + struct btrfs_leaf *leaf; + struct buffer_head *leaf_buf; + u32 nritems; + unsigned int data_end; + unsigned int old_data; + unsigned int old_size; + int i; + + slot_orig = path->slots[0]; + leaf_buf = path->nodes[0]; + leaf = btrfs_buffer_leaf(leaf_buf); + + nritems = btrfs_header_nritems(&leaf->header); + data_end = leaf_data_end(root, leaf); + + if (btrfs_leaf_free_space(root, leaf) < data_size) + BUG(); + slot = path->slots[0]; + old_data = btrfs_item_end(leaf->items + slot); + + BUG_ON(slot < 0); + BUG_ON(slot >= nritems); + + /* + * item0..itemN ... dataN.offset..dataN.size .. data0.size + */ + /* first correct the data pointers */ + for (i = slot; i < nritems; i++) { + u32 ioff = btrfs_item_offset(leaf->items + i); + btrfs_set_item_offset(leaf->items + i, + ioff - data_size); + } + /* shift the data */ + btrfs_memmove(root, leaf, btrfs_leaf_data(leaf) + + data_end - data_size, btrfs_leaf_data(leaf) + + data_end, old_data - data_end); + data_end = old_data; + old_size = btrfs_item_size(leaf->items + slot); + btrfs_set_item_size(leaf->items + slot, old_size + data_size); + btrfs_mark_buffer_dirty(leaf_buf); + + ret = 0; + if (btrfs_leaf_free_space(root, leaf) < 0) + BUG(); + check_leaf(root, path, 0); + return ret; +} + /* * Given a key and some data, insert an item into the tree. * This does all the path init required, making room in the tree if needed. diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index ef3583cf74d6..796f19d03ab5 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -227,6 +227,7 @@ struct btrfs_file_extent_item { } __attribute__ ((__packed__)); struct btrfs_csum_item { + __le64 extent_offset; u8 csum[BTRFS_CSUM_SIZE]; } __attribute__ ((__packed__)); @@ -924,6 +925,17 @@ static inline void btrfs_set_file_extent_num_blocks(struct e->num_blocks = cpu_to_le64(val); } +static inline u64 btrfs_csum_extent_offset(struct btrfs_csum_item *c) +{ + return le64_to_cpu(c->extent_offset); +} + +static inline void btrfs_set_csum_extent_offset(struct btrfs_csum_item *c, + u64 val) +{ + c->extent_offset = cpu_to_le64(val); +} + static inline u16 btrfs_device_pathlen(struct btrfs_device_item *d) { return le16_to_cpu(d->pathlen); @@ -1002,6 +1014,8 @@ int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans, struct btrfs_root *root); /* ctree.c */ +int btrfs_extend_item(struct btrfs_trans_handle *trans, struct btrfs_root + *root, struct btrfs_path *path, u32 data_size); int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_key *key, struct btrfs_path *p, int ins_len, int cow); @@ -1071,6 +1085,7 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans, int btrfs_csum_file_block(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 objectid, u64 offset, + u64 extent_offset, char *data, size_t len); int btrfs_csum_verify_file_block(struct btrfs_root *root, u64 objectid, u64 offset, diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c index d9fd7f4d3794..93d42d650820 100644 --- a/fs/btrfs/file-item.c +++ b/fs/btrfs/file-item.c @@ -3,6 +3,9 @@ #include "disk-io.h" #include "transaction.h" +#define MAX_CSUM_ITEMS(r) ((((BTRFS_LEAF_DATA_SIZE(r) - \ + sizeof(struct btrfs_item)) / \ + sizeof(struct btrfs_csum_item)) - 1)) int btrfs_alloc_file_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 objectid, u64 offset, @@ -43,6 +46,54 @@ int btrfs_alloc_file_extent(struct btrfs_trans_handle *trans, return 0; } +static struct btrfs_csum_item *__lookup_csum_item(struct btrfs_root *root, + struct btrfs_path *path, + u64 objectid, u64 offset) +{ + int ret; + struct btrfs_key file_key; + struct btrfs_key found_key; + struct btrfs_csum_item *item; + struct btrfs_leaf *leaf; + u64 csum_offset = 0; + + file_key.objectid = objectid; + file_key.offset = offset; + file_key.flags = 0; + btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY); + ret = btrfs_search_slot(NULL, root, &file_key, path, 0, 0); + if (ret < 0) + goto fail; + leaf = btrfs_buffer_leaf(path->nodes[0]); + if (ret > 0) { + ret = 1; + if (path->slots[0] == 0) + goto fail; + path->slots[0]--; + btrfs_disk_key_to_cpu(&found_key, + &leaf->items[path->slots[0]].key); + if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY || + found_key.objectid != objectid) { + goto fail; + } + csum_offset = (offset - found_key.offset) >> + root->fs_info->sb->s_blocksize_bits; + if (csum_offset >= + btrfs_item_size(leaf->items + path->slots[0]) / + sizeof(struct btrfs_csum_item)) { + goto fail; + } + } + item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item); + item += csum_offset; + return item; +fail: + if (ret > 0) + ret = -EIO; + return ERR_PTR(ret); +} + + int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, u64 objectid, @@ -52,11 +103,16 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans, struct btrfs_key file_key; int ins_len = mod < 0 ? -1 : 0; int cow = mod != 0; + struct btrfs_csum_item *csum_item; + csum_item = __lookup_csum_item(root, path, objectid, offset); + if (IS_ERR(csum_item)) + return PTR_ERR(csum_item); file_key.objectid = objectid; - file_key.offset = offset; + file_key.offset = btrfs_csum_extent_offset(csum_item); file_key.flags = 0; btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY); + btrfs_release_path(root, path); ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow); return ret; } @@ -64,12 +120,16 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans, int btrfs_csum_file_block(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 objectid, u64 offset, + u64 extent_offset, char *data, size_t len) { int ret; struct btrfs_key file_key; + struct btrfs_key found_key; struct btrfs_path *path; struct btrfs_csum_item *item; + struct btrfs_leaf *leaf; + u64 csum_offset; path = btrfs_alloc_path(); BUG_ON(!path); @@ -78,14 +138,50 @@ int btrfs_csum_file_block(struct btrfs_trans_handle *trans, file_key.offset = offset; file_key.flags = 0; btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY); + ret = btrfs_search_slot(trans, root, &file_key, path, + sizeof(struct btrfs_csum_item), 1); + if (ret < 0) + goto fail; + if (ret == 0) { + csum_offset = 0; + goto csum; + } + if (path->slots[0] == 0) { + btrfs_release_path(root, path); + goto insert; + } + path->slots[0]--; + leaf = btrfs_buffer_leaf(path->nodes[0]); + btrfs_disk_key_to_cpu(&found_key, &leaf->items[path->slots[0]].key); + csum_offset = (offset - found_key.offset) >> + root->fs_info->sb->s_blocksize_bits; + if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY || + found_key.objectid != objectid || + csum_offset >= MAX_CSUM_ITEMS(root)) { + btrfs_release_path(root, path); + goto insert; + } + if (csum_offset >= btrfs_item_size(leaf->items + path->slots[0]) / + sizeof(struct btrfs_csum_item)) { + ret = btrfs_extend_item(trans, root, path, + sizeof(struct btrfs_csum_item)); + BUG_ON(ret); + goto csum; + } + +insert: + csum_offset = 0; ret = btrfs_insert_empty_item(trans, root, path, &file_key, - BTRFS_CSUM_SIZE); + sizeof(struct btrfs_csum_item)); if (ret != 0 && ret != -EEXIST) goto fail; +csum: item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0], struct btrfs_csum_item); ret = 0; + item += csum_offset; ret = btrfs_csum_data(root, data, len, item->csum); + btrfs_set_csum_extent_offset(item, extent_offset); btrfs_mark_buffer_dirty(path->nodes[0]); fail: btrfs_release_path(root, path); @@ -111,12 +207,13 @@ int btrfs_csum_verify_file_block(struct btrfs_root *root, file_key.flags = 0; btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY); mutex_lock(&root->fs_info->fs_mutex); - ret = btrfs_search_slot(NULL, root, &file_key, path, 0, 0); - if (ret) + + item = __lookup_csum_item(root, path, objectid, offset); + if (IS_ERR(item)) { + ret = PTR_ERR(item); goto fail; - item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0], - struct btrfs_csum_item); - ret = 0; + } + ret = btrfs_csum_data(root, data, len, result); WARN_ON(ret); if (memcmp(result, item->csum, BTRFS_CSUM_SIZE)) diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 8dcf600e39ef..ec689992fdf4 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -1027,8 +1027,10 @@ static int btrfs_get_block_lock(struct inode *inode, sector_t iblock, path = btrfs_alloc_path(); BUG_ON(!path); btrfs_init_path(path); - if (create) + if (create) { trans = btrfs_start_transaction(root, 1); + WARN_ON(1); + } ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino, @@ -1055,9 +1057,8 @@ static int btrfs_get_block_lock(struct inode *inode, sector_t iblock, /* exact match found, use it, FIXME, deal with extents * other than the page size */ - if (ret == 0) { + if (0 && ret == 0) { err = 0; - BUG_ON(btrfs_file_extent_disk_num_blocks(item) != 1); if (create && btrfs_file_extent_generation(item) != trans->transid) { struct btrfs_key ins; @@ -1072,7 +1073,6 @@ static int btrfs_get_block_lock(struct inode *inode, sector_t iblock, blocknr = ins.objectid; } - map_bh(result, inode->i_sb, blocknr); btrfs_map_bh_to_logical(root, result, blocknr); goto out; } @@ -1231,6 +1231,7 @@ static int dirty_and_release_pages(struct btrfs_trans_handle *trans, struct file *file, struct page **pages, size_t num_pages, + u64 extent_offset, loff_t pos, size_t write_bytes) { @@ -1250,6 +1251,7 @@ static int dirty_and_release_pages(struct btrfs_trans_handle *trans, trans = btrfs_start_transaction(root, 1); btrfs_csum_file_block(trans, root, inode->i_ino, pages[i]->index << PAGE_CACHE_SHIFT, + extent_offset, kmap(pages[i]), PAGE_CACHE_SIZE); kunmap(pages[i]); SetPageChecked(pages[i]); @@ -1279,7 +1281,8 @@ static int prepare_pages(struct btrfs_trans_handle *trans, loff_t pos, unsigned long first_index, unsigned long last_index, - size_t write_bytes) + size_t write_bytes, + u64 alloc_extent_start) { int i; unsigned long index = pos >> PAGE_CACHE_SHIFT; @@ -1288,6 +1291,8 @@ static int prepare_pages(struct btrfs_trans_handle *trans, int err = 0; int ret; int this_write; + struct buffer_head *bh; + struct buffer_head *head; loff_t isize = i_size_read(inode); memset(pages, 0, num_pages * sizeof(struct page *)); @@ -1307,14 +1312,20 @@ static int prepare_pages(struct btrfs_trans_handle *trans, BUG_ON(ret); lock_page(pages[i]); } - ret = nobh_prepare_write(pages[i], offset, - offset + this_write, - btrfs_get_block); + create_empty_buffers(pages[i], root->fs_info->sb->s_blocksize, + (1 << BH_Uptodate)); + head = page_buffers(pages[i]); + bh = head; + do { + err = btrfs_map_bh_to_logical(root, bh, + alloc_extent_start); + BUG_ON(err); + if (err) + goto failed_truncate; + bh = bh->b_this_page; + alloc_extent_start++; + } while (bh != head); pos += this_write; - if (ret) { - err = ret; - goto failed_truncate; - } WARN_ON(this_write > write_bytes); write_bytes -= this_write; } @@ -1343,11 +1354,23 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf, struct page *pages[1]; unsigned long first_index; unsigned long last_index; + u64 start_pos; + u64 num_blocks; + u64 alloc_extent_start; + u64 orig_extent_start; + struct btrfs_trans_handle *trans; if (file->f_flags & O_DIRECT) return -EINVAL; pos = *ppos; + start_pos = pos & ~(root->blocksize - 1); + /* FIXME */ + if (start_pos != pos) + return -EINVAL; + num_blocks = (count + pos - start_pos + root->blocksize - 1) >> + inode->i_blkbits; + vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE); current->backing_dev_info = inode->i_mapping->backing_dev_info; err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode)); @@ -1362,20 +1385,41 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf, mutex_lock(&inode->i_mutex); first_index = pos >> PAGE_CACHE_SHIFT; last_index = (pos + count) >> PAGE_CACHE_SHIFT; + + mutex_lock(&root->fs_info->fs_mutex); + trans = btrfs_start_transaction(root, 1); + if (!trans) { + err = -ENOMEM; + goto out_unlock; + } + ret = btrfs_alloc_file_extent(trans, root, inode->i_ino, + start_pos, num_blocks, 1, + &alloc_extent_start); + BUG_ON(ret); + + orig_extent_start = start_pos; + ret = btrfs_end_transaction(trans, root); + BUG_ON(ret); + mutex_unlock(&root->fs_info->fs_mutex); + while(count > 0) { size_t offset = pos & (PAGE_CACHE_SIZE - 1); size_t write_bytes = min(count, PAGE_CACHE_SIZE - offset); size_t num_pages = (write_bytes + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; ret = prepare_pages(NULL, root, file, pages, num_pages, - pos, first_index, last_index, write_bytes); + pos, first_index, last_index, + write_bytes, alloc_extent_start); BUG_ON(ret); + /* FIXME blocks != pagesize */ + alloc_extent_start += num_pages; ret = btrfs_copy_from_user(pos, num_pages, write_bytes, pages, buf); BUG_ON(ret); ret = dirty_and_release_pages(NULL, root, file, pages, - num_pages, pos, write_bytes); + num_pages, orig_extent_start, + pos, write_bytes); BUG_ON(ret); btrfs_drop_pages(pages, num_pages); @@ -1387,6 +1431,7 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf, balance_dirty_pages_ratelimited(inode->i_mapping); cond_resched(); } +out_unlock: mutex_unlock(&inode->i_mutex); out: *ppos = pos; @@ -1806,8 +1851,6 @@ static int create_snapshot(struct btrfs_root *root, char *name, int namelen) &new_root_item); BUG_ON(ret); -printk("adding snapshot name %.*s root %Lu %Lu %u\n", namelen, name, key.objectid, key.offset, key.flags); - /* * insert the directory item */