From 2242c689ecc390fb4719f595751351d1ecc5c409 Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Fri, 5 Sep 2008 11:56:05 +0300 Subject: UBIFS: improve znode splitting rules When inserting into a full znode it is split into two znodes. Because data node keys are usually consecutive, it is better to try to keep them together. This patch does a better job of that. Signed-off-by: Adrian Hunter --- fs/ubifs/tnc.c | 54 +++++++++++++++++++++++++++++++++--------------------- 1 file changed, 33 insertions(+), 21 deletions(-) (limited to 'fs/ubifs') diff --git a/fs/ubifs/tnc.c b/fs/ubifs/tnc.c index 66dc57100bd..e0878a431b9 100644 --- a/fs/ubifs/tnc.c +++ b/fs/ubifs/tnc.c @@ -1962,7 +1962,7 @@ static int tnc_insert(struct ubifs_info *c, struct ubifs_znode *znode, { struct ubifs_znode *zn, *zi, *zp; int i, keep, move, appending = 0; - union ubifs_key *key = &zbr->key; + union ubifs_key *key = &zbr->key, *key1; ubifs_assert(n >= 0 && n <= c->fanout); @@ -2003,20 +2003,33 @@ again: zn->level = znode->level; /* Decide where to split */ - if (znode->level == 0 && n == c->fanout && - key_type(c, key) == UBIFS_DATA_KEY) { - union ubifs_key *key1; - - /* - * If this is an inode which is being appended - do not split - * it because no other zbranches can be inserted between - * zbranches of consecutive data nodes anyway. - */ - key1 = &znode->zbranch[n - 1].key; - if (key_inum(c, key1) == key_inum(c, key) && - key_type(c, key1) == UBIFS_DATA_KEY && - key_block(c, key1) == key_block(c, key) - 1) - appending = 1; + if (znode->level == 0 && key_type(c, key) == UBIFS_DATA_KEY) { + /* Try not to split consecutive data keys */ + if (n == c->fanout) { + key1 = &znode->zbranch[n - 1].key; + if (key_inum(c, key1) == key_inum(c, key) && + key_type(c, key1) == UBIFS_DATA_KEY) + appending = 1; + } else + goto check_split; + } else if (appending && n != c->fanout) { + /* Try not to split consecutive data keys */ + appending = 0; +check_split: + if (n >= (c->fanout + 1) / 2) { + key1 = &znode->zbranch[0].key; + if (key_inum(c, key1) == key_inum(c, key) && + key_type(c, key1) == UBIFS_DATA_KEY) { + key1 = &znode->zbranch[n].key; + if (key_inum(c, key1) != key_inum(c, key) || + key_type(c, key1) != UBIFS_DATA_KEY) { + keep = n; + move = c->fanout - keep; + zi = znode; + goto do_split; + } + } + } } if (appending) { @@ -2046,6 +2059,8 @@ again: zbr->znode->parent = zn; } +do_split: + __set_bit(DIRTY_ZNODE, &zn->flags); atomic_long_inc(&c->dirty_zn_cnt); @@ -2072,14 +2087,11 @@ again: /* Insert new znode (produced by spitting) into the parent */ if (zp) { - i = n; + if (n == 0 && zi == znode && znode->iip == 0) + correct_parent_keys(c, znode); + /* Locate insertion point */ n = znode->iip + 1; - if (appending && n != c->fanout) - appending = 0; - - if (i == 0 && zi == znode && znode->iip == 0) - correct_parent_keys(c, znode); /* Tail recursion */ zbr->key = zn->zbranch[0].key; -- cgit v1.2.3