From 34a3821873aeabff2607c8093bce82cd1fbcfd60 Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Wed, 7 Nov 2007 13:31:03 -0500 Subject: [PATCH] Btrfs: Change push_leaf_{leaf,right} to empty the src leave during item deletion Signed-off-by: Chris Mason --- fs/btrfs/ctree.c | 72 ++++++++++++++++++++++++++++++++---------------- 1 file changed, 49 insertions(+), 23 deletions(-) diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index ea9b46699349..1b47fe71e0b4 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -1394,19 +1394,21 @@ int btrfs_leaf_free_space(struct btrfs_root *root, struct extent_buffer *leaf) * room, 0 if everything worked out and < 0 if there were major errors. */ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root - *root, struct btrfs_path *path, int data_size) + *root, struct btrfs_path *path, int data_size, + int empty) { struct extent_buffer *left = path->nodes[0]; struct extent_buffer *right; struct extent_buffer *upper; struct btrfs_disk_key disk_key; int slot; - int i; + u32 i; int free_space; int push_space = 0; int push_items = 0; struct btrfs_item *item; u32 left_nritems; + u32 nr; u32 right_nritems; u32 data_end; u32 this_item_size; @@ -1447,7 +1449,13 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root return 1; } - for (i = left_nritems - 1; i >= 1; i--) { + if (empty) + nr = 0; + else + nr = 1; + + i = left_nritems - 1; + while (i >= nr) { item = btrfs_item_nr(left, i); if (path->slots[0] == i) @@ -1466,6 +1474,9 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root break; push_items++; push_space += this_item_size + sizeof(*item); + if (i == 0) + break; + i--; } if (left->map_token) { unmap_extent_buffer(left, left->map_token, KM_USER1); @@ -1477,11 +1488,12 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root return 1; } - if (push_items == left_nritems) + if (!empty && push_items == left_nritems) WARN_ON(1); /* push left to right */ right_nritems = btrfs_header_nritems(right); + push_space = btrfs_item_end_nr(left, left_nritems - push_items); push_space -= leaf_data_end(root, left); @@ -1511,7 +1523,6 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root right_nritems += push_items; btrfs_set_header_nritems(right, right_nritems); push_space = BTRFS_LEAF_DATA_SIZE(root); - for (i = 0; i < right_nritems; i++) { item = btrfs_item_nr(right, i); if (!right->map_token) { @@ -1532,7 +1543,8 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root left_nritems -= push_items; btrfs_set_header_nritems(left, left_nritems); - btrfs_mark_buffer_dirty(left); + if (left_nritems) + btrfs_mark_buffer_dirty(left); btrfs_mark_buffer_dirty(right); btrfs_item_key(right, &disk_key, 0); @@ -1555,7 +1567,8 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root * least data_size bytes. returns zero if the push worked, nonzero otherwise */ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root - *root, struct btrfs_path *path, int data_size) + *root, struct btrfs_path *path, int data_size, + int empty) { struct btrfs_disk_key disk_key; struct extent_buffer *right = path->nodes[0]; @@ -1568,6 +1581,7 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root struct btrfs_item *item; u32 old_left_nritems; u32 right_nritems; + u32 nr; int ret = 0; int wret; u32 this_item_size; @@ -1607,7 +1621,12 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root return 1; } - for (i = 0; i < right_nritems - 1; i++) { + if (empty) + nr = right_nritems; + else + nr = right_nritems - 1; + + for (i = 0; i < nr; i++) { item = btrfs_item_nr(right, i); if (!right->map_token) { map_extent_buffer(right, (unsigned long)item, @@ -1637,7 +1656,7 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root free_extent_buffer(left); return 1; } - if (push_items == btrfs_header_nritems(right)) + if (!empty && push_items == btrfs_header_nritems(right)) WARN_ON(1); /* push data from right to left */ @@ -1681,20 +1700,26 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root } /* fixup right node */ - push_space = btrfs_item_offset_nr(right, push_items - 1) - - leaf_data_end(root, right); - memmove_extent_buffer(right, btrfs_leaf_data(right) + - BTRFS_LEAF_DATA_SIZE(root) - push_space, - btrfs_leaf_data(right) + - leaf_data_end(root, right), push_space); + if (push_items > right_nritems) { + printk("push items %d nr %u\n", push_items, right_nritems); + WARN_ON(1); + } - memmove_extent_buffer(right, btrfs_item_nr_offset(0), + if (push_items < right_nritems) { + push_space = btrfs_item_offset_nr(right, push_items - 1) - + leaf_data_end(root, right); + memmove_extent_buffer(right, btrfs_leaf_data(right) + + BTRFS_LEAF_DATA_SIZE(root) - push_space, + btrfs_leaf_data(right) + + leaf_data_end(root, right), push_space); + + memmove_extent_buffer(right, btrfs_item_nr_offset(0), btrfs_item_nr_offset(push_items), (btrfs_header_nritems(right) - push_items) * sizeof(struct btrfs_item)); - right_nritems = btrfs_header_nritems(right) - push_items; - btrfs_set_header_nritems(right, right_nritems); + } + btrfs_set_header_nritems(right, right_nritems - push_items); push_space = BTRFS_LEAF_DATA_SIZE(root); for (i = 0; i < right_nritems; i++) { @@ -1717,7 +1742,8 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root } btrfs_mark_buffer_dirty(left); - btrfs_mark_buffer_dirty(right); + if (right_nritems) + btrfs_mark_buffer_dirty(right); btrfs_item_key(right, &disk_key, 0); wret = fixup_low_keys(trans, root, path, &disk_key, 1); @@ -1768,12 +1794,12 @@ static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root /* first try to make some room by pushing left and right */ if (ins_key->type != BTRFS_DIR_ITEM_KEY) { - wret = push_leaf_right(trans, root, path, data_size); + wret = push_leaf_right(trans, root, path, data_size, 0); if (wret < 0) { return wret; } if (wret) { - wret = push_leaf_left(trans, root, path, data_size); + wret = push_leaf_left(trans, root, path, data_size, 0); if (wret < 0) return wret; } @@ -2403,13 +2429,13 @@ int btrfs_del_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, slot = path->slots[1]; extent_buffer_get(leaf); - wret = push_leaf_right(trans, root, path, 1); + wret = push_leaf_right(trans, root, path, 1, 1); if (wret < 0 && wret != -ENOSPC) ret = wret; if (path->nodes[0] == leaf && btrfs_header_nritems(leaf)) { - wret = push_leaf_left(trans, root, path, 1); + wret = push_leaf_left(trans, root, path, 1, 1); if (wret < 0 && wret != -ENOSPC) ret = wret; }