From 9eaead51bed957af0070a277d945744a76df0c8b Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 30 Oct 2008 16:56:43 +1100 Subject: [XFS] implement generic xfs_btree_rshift Make the btree right shift code generic. Based on a patch from David Chinner with lots of changes to follow the original btree implementations more closely. While this loses some of the generic helper routines for inserting/moving/removing records it also solves some of the one off bugs in the original code and makes it easier to verify. SGI-PV: 985583 SGI-Modid: xfs-linux-melb:xfs-kern:32196a Signed-off-by: Christoph Hellwig Signed-off-by: Lachlan McIlroy Signed-off-by: Bill O'Donnell Signed-off-by: David Chinner --- fs/xfs/xfs_alloc_btree.c | 136 +---------------------------------------------- 1 file changed, 2 insertions(+), 134 deletions(-) (limited to 'fs/xfs/xfs_alloc_btree.c') diff --git a/fs/xfs/xfs_alloc_btree.c b/fs/xfs/xfs_alloc_btree.c index c5c32999b810..31e42891fc9a 100644 --- a/fs/xfs/xfs_alloc_btree.c +++ b/fs/xfs/xfs_alloc_btree.c @@ -49,7 +49,6 @@ STATIC void xfs_alloc_log_ptrs(xfs_btree_cur_t *, xfs_buf_t *, int, int); STATIC void xfs_alloc_log_recs(xfs_btree_cur_t *, xfs_buf_t *, int, int); STATIC int xfs_alloc_lshift(xfs_btree_cur_t *, int, int *); STATIC int xfs_alloc_newroot(xfs_btree_cur_t *, int *); -STATIC int xfs_alloc_rshift(xfs_btree_cur_t *, int, int *); STATIC int xfs_alloc_split(xfs_btree_cur_t *, int, xfs_agblock_t *, xfs_alloc_key_t *, xfs_btree_cur_t **, int *); @@ -391,7 +390,7 @@ xfs_alloc_delrec( */ if (be16_to_cpu(left->bb_numrecs) - 1 >= XFS_ALLOC_BLOCK_MINRECS(level, cur)) { - if ((error = xfs_alloc_rshift(tcur, level, &i))) + if ((error = xfs_btree_rshift(tcur, level, &i))) goto error0; if (i) { ASSERT(be16_to_cpu(block->bb_numrecs) >= @@ -683,7 +682,7 @@ xfs_alloc_insrec( /* * First, try shifting an entry to the right neighbor. */ - if ((error = xfs_alloc_rshift(cur, level, &i))) + if ((error = xfs_btree_rshift(cur, level, &i))) return error; if (i) { /* nothing */ @@ -1232,137 +1231,6 @@ xfs_alloc_newroot( return 0; } -/* - * Move 1 record right from cur/level if possible. - * Update cur to reflect the new path. - */ -STATIC int /* error */ -xfs_alloc_rshift( - xfs_btree_cur_t *cur, /* btree cursor */ - int level, /* level to shift record on */ - int *stat) /* success/failure */ -{ - int error; /* error return value */ - int i; /* loop index */ - xfs_alloc_key_t key; /* key value for leaf level upward */ - xfs_buf_t *lbp; /* buffer for left (current) block */ - xfs_alloc_block_t *left; /* left (current) btree block */ - xfs_buf_t *rbp; /* buffer for right neighbor block */ - xfs_alloc_block_t *right; /* right neighbor btree block */ - xfs_alloc_key_t *rkp; /* key pointer for right block */ - xfs_btree_cur_t *tcur; /* temporary cursor */ - - /* - * Set up variables for this block as "left". - */ - lbp = cur->bc_bufs[level]; - left = XFS_BUF_TO_ALLOC_BLOCK(lbp); -#ifdef DEBUG - if ((error = xfs_btree_check_sblock(cur, left, level, lbp))) - return error; -#endif - /* - * If we've got no right sibling then we can't shift an entry right. - */ - if (be32_to_cpu(left->bb_rightsib) == NULLAGBLOCK) { - *stat = 0; - return 0; - } - /* - * If the cursor entry is the one that would be moved, don't - * do it... it's too complicated. - */ - if (cur->bc_ptrs[level] >= be16_to_cpu(left->bb_numrecs)) { - *stat = 0; - return 0; - } - /* - * Set up the right neighbor as "right". - */ - if ((error = xfs_btree_read_bufs(cur->bc_mp, cur->bc_tp, - cur->bc_private.a.agno, be32_to_cpu(left->bb_rightsib), - 0, &rbp, XFS_ALLOC_BTREE_REF))) - return error; - right = XFS_BUF_TO_ALLOC_BLOCK(rbp); - if ((error = xfs_btree_check_sblock(cur, right, level, rbp))) - return error; - /* - * If it's full, it can't take another entry. - */ - if (be16_to_cpu(right->bb_numrecs) == XFS_ALLOC_BLOCK_MAXRECS(level, cur)) { - *stat = 0; - return 0; - } - /* - * Make a hole at the start of the right neighbor block, then - * copy the last left block entry to the hole. - */ - if (level > 0) { - xfs_alloc_key_t *lkp; /* key pointer for left block */ - xfs_alloc_ptr_t *lpp; /* address pointer for left block */ - xfs_alloc_ptr_t *rpp; /* address pointer for right block */ - - lkp = XFS_ALLOC_KEY_ADDR(left, be16_to_cpu(left->bb_numrecs), cur); - lpp = XFS_ALLOC_PTR_ADDR(left, be16_to_cpu(left->bb_numrecs), cur); - rkp = XFS_ALLOC_KEY_ADDR(right, 1, cur); - rpp = XFS_ALLOC_PTR_ADDR(right, 1, cur); -#ifdef DEBUG - for (i = be16_to_cpu(right->bb_numrecs) - 1; i >= 0; i--) { - if ((error = xfs_btree_check_sptr(cur, be32_to_cpu(rpp[i]), level))) - return error; - } -#endif - memmove(rkp + 1, rkp, be16_to_cpu(right->bb_numrecs) * sizeof(*rkp)); - memmove(rpp + 1, rpp, be16_to_cpu(right->bb_numrecs) * sizeof(*rpp)); -#ifdef DEBUG - if ((error = xfs_btree_check_sptr(cur, be32_to_cpu(*lpp), level))) - return error; -#endif - *rkp = *lkp; - *rpp = *lpp; - xfs_alloc_log_keys(cur, rbp, 1, be16_to_cpu(right->bb_numrecs) + 1); - xfs_alloc_log_ptrs(cur, rbp, 1, be16_to_cpu(right->bb_numrecs) + 1); - xfs_btree_check_key(cur->bc_btnum, rkp, rkp + 1); - } else { - xfs_alloc_rec_t *lrp; /* record pointer for left block */ - xfs_alloc_rec_t *rrp; /* record pointer for right block */ - - lrp = XFS_ALLOC_REC_ADDR(left, be16_to_cpu(left->bb_numrecs), cur); - rrp = XFS_ALLOC_REC_ADDR(right, 1, cur); - memmove(rrp + 1, rrp, be16_to_cpu(right->bb_numrecs) * sizeof(*rrp)); - *rrp = *lrp; - xfs_alloc_log_recs(cur, rbp, 1, be16_to_cpu(right->bb_numrecs) + 1); - key.ar_startblock = rrp->ar_startblock; - key.ar_blockcount = rrp->ar_blockcount; - rkp = &key; - xfs_btree_check_rec(cur->bc_btnum, rrp, rrp + 1); - } - /* - * Decrement and log left's numrecs, bump and log right's numrecs. - */ - be16_add_cpu(&left->bb_numrecs, -1); - xfs_alloc_log_block(cur->bc_tp, lbp, XFS_BB_NUMRECS); - be16_add_cpu(&right->bb_numrecs, 1); - xfs_alloc_log_block(cur->bc_tp, rbp, XFS_BB_NUMRECS); - /* - * Using a temporary cursor, update the parent key values of the - * block on the right. - */ - if ((error = xfs_btree_dup_cursor(cur, &tcur))) - return error; - i = xfs_btree_lastrec(tcur, level); - XFS_WANT_CORRUPTED_GOTO(i == 1, error0); - if ((error = xfs_btree_increment(tcur, level, &i)) || - (error = xfs_btree_updkey(tcur, (union xfs_btree_key *)rkp, level + 1))) - goto error0; - xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR); - *stat = 1; - return 0; -error0: - xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR); - return error; -} - /* * Split cur/level block in half. * Return new block number and its first record (to be inserted into parent). -- cgit v1.2.3