From f5eb8e7ca58bc1e92436614444006120d21668ba Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 30 Oct 2008 16:57:03 +1100 Subject: [XFS] implement generic xfs_btree_split Make the btree split 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:32198a 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 | 200 ++++++++++------------------------------------- 1 file changed, 42 insertions(+), 158 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 974a412ebc8..8a8d1aeec52 100644 --- a/fs/xfs/xfs_alloc_btree.c +++ b/fs/xfs/xfs_alloc_btree.c @@ -35,6 +35,7 @@ #include "xfs_dinode.h" #include "xfs_inode.h" #include "xfs_btree.h" +#include "xfs_btree_trace.h" #include "xfs_ialloc.h" #include "xfs_alloc.h" #include "xfs_error.h" @@ -48,8 +49,6 @@ STATIC void xfs_alloc_log_keys(xfs_btree_cur_t *, xfs_buf_t *, int, int); 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_newroot(xfs_btree_cur_t *, int *); -STATIC int xfs_alloc_split(xfs_btree_cur_t *, int, xfs_agblock_t *, - xfs_alloc_key_t *, xfs_btree_cur_t **, int *); /* * Internal functions. @@ -695,15 +694,18 @@ xfs_alloc_insrec( if (i) optr = ptr = cur->bc_ptrs[level]; else { + union xfs_btree_ptr bno = { .s = cpu_to_be32(nbno) }; /* * Next, try splitting the current block in * half. If this works we have to re-set our * variables because we could be in a * different block now. */ - if ((error = xfs_alloc_split(cur, level, &nbno, - &nkey, &ncur, &i))) + if ((error = xfs_btree_split(cur, level, &bno, + (union xfs_btree_key *)&nkey, + &ncur, &i))) return error; + nbno = be32_to_cpu(bno.s); if (i) { bp = cur->bc_bufs[level]; block = XFS_BUF_TO_ALLOC_BLOCK(bp); @@ -1089,160 +1091,6 @@ xfs_alloc_newroot( return 0; } -/* - * Split cur/level block in half. - * Return new block number and its first record (to be inserted into parent). - */ -STATIC int /* error */ -xfs_alloc_split( - xfs_btree_cur_t *cur, /* btree cursor */ - int level, /* level to split */ - xfs_agblock_t *bnop, /* output: block number allocated */ - xfs_alloc_key_t *keyp, /* output: first key of new block */ - xfs_btree_cur_t **curp, /* output: new cursor */ - int *stat) /* success/failure */ -{ - int error; /* error return value */ - int i; /* loop index/record number */ - xfs_agblock_t lbno; /* left (current) block number */ - xfs_buf_t *lbp; /* buffer for left block */ - xfs_alloc_block_t *left; /* left (current) btree block */ - xfs_agblock_t rbno; /* right (new) block number */ - xfs_buf_t *rbp; /* buffer for right block */ - xfs_alloc_block_t *right; /* right (new) btree block */ - - /* - * Allocate the new block from the freelist. - * If we can't do it, we're toast. Give up. - */ - error = xfs_alloc_get_freelist(cur->bc_tp, - cur->bc_private.a.agbp, &rbno, 1); - if (error) - return error; - if (rbno == NULLAGBLOCK) { - *stat = 0; - return 0; - } - xfs_trans_agbtree_delta(cur->bc_tp, 1); - rbp = xfs_btree_get_bufs(cur->bc_mp, cur->bc_tp, cur->bc_private.a.agno, - rbno, 0); - /* - * Set up the new block as "right". - */ - right = XFS_BUF_TO_ALLOC_BLOCK(rbp); - /* - * "Left" is the current (according to the cursor) block. - */ - 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 - /* - * Fill in the btree header for the new block. - */ - right->bb_magic = cpu_to_be32(xfs_magics[cur->bc_btnum]); - right->bb_level = left->bb_level; - right->bb_numrecs = cpu_to_be16(be16_to_cpu(left->bb_numrecs) / 2); - /* - * Make sure that if there's an odd number of entries now, that - * each new block will have the same number of entries. - */ - if ((be16_to_cpu(left->bb_numrecs) & 1) && - cur->bc_ptrs[level] <= be16_to_cpu(right->bb_numrecs) + 1) - be16_add_cpu(&right->bb_numrecs, 1); - i = be16_to_cpu(left->bb_numrecs) - be16_to_cpu(right->bb_numrecs) + 1; - /* - * For non-leaf blocks, copy keys and addresses over to the new block. - */ - if (level > 0) { - xfs_alloc_key_t *lkp; /* left btree key pointer */ - xfs_alloc_ptr_t *lpp; /* left btree address pointer */ - xfs_alloc_key_t *rkp; /* right btree key pointer */ - xfs_alloc_ptr_t *rpp; /* right btree address pointer */ - - lkp = XFS_ALLOC_KEY_ADDR(left, i, cur); - lpp = XFS_ALLOC_PTR_ADDR(left, i, cur); - rkp = XFS_ALLOC_KEY_ADDR(right, 1, cur); - rpp = XFS_ALLOC_PTR_ADDR(right, 1, cur); -#ifdef DEBUG - for (i = 0; i < be16_to_cpu(right->bb_numrecs); i++) { - if ((error = xfs_btree_check_sptr(cur, be32_to_cpu(lpp[i]), level))) - return error; - } -#endif - memcpy(rkp, lkp, be16_to_cpu(right->bb_numrecs) * sizeof(*rkp)); - memcpy(rpp, lpp, be16_to_cpu(right->bb_numrecs) * sizeof(*rpp)); - xfs_alloc_log_keys(cur, rbp, 1, be16_to_cpu(right->bb_numrecs)); - xfs_alloc_log_ptrs(cur, rbp, 1, be16_to_cpu(right->bb_numrecs)); - *keyp = *rkp; - } - /* - * For leaf blocks, copy records over to the new block. - */ - else { - xfs_alloc_rec_t *lrp; /* left btree record pointer */ - xfs_alloc_rec_t *rrp; /* right btree record pointer */ - - lrp = XFS_ALLOC_REC_ADDR(left, i, cur); - rrp = XFS_ALLOC_REC_ADDR(right, 1, cur); - memcpy(rrp, lrp, be16_to_cpu(right->bb_numrecs) * sizeof(*rrp)); - xfs_alloc_log_recs(cur, rbp, 1, be16_to_cpu(right->bb_numrecs)); - keyp->ar_startblock = rrp->ar_startblock; - keyp->ar_blockcount = rrp->ar_blockcount; - } - /* - * Find the left block number by looking in the buffer. - * Adjust numrecs, sibling pointers. - */ - lbno = XFS_DADDR_TO_AGBNO(cur->bc_mp, XFS_BUF_ADDR(lbp)); - be16_add_cpu(&left->bb_numrecs, -(be16_to_cpu(right->bb_numrecs))); - right->bb_rightsib = left->bb_rightsib; - left->bb_rightsib = cpu_to_be32(rbno); - right->bb_leftsib = cpu_to_be32(lbno); - xfs_alloc_log_block(cur->bc_tp, rbp, XFS_BB_ALL_BITS); - xfs_alloc_log_block(cur->bc_tp, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB); - /* - * If there's a block to the new block's right, make that block - * point back to right instead of to left. - */ - if (be32_to_cpu(right->bb_rightsib) != NULLAGBLOCK) { - xfs_alloc_block_t *rrblock; /* rr btree block */ - xfs_buf_t *rrbp; /* buffer for rrblock */ - - if ((error = xfs_btree_read_bufs(cur->bc_mp, cur->bc_tp, - cur->bc_private.a.agno, be32_to_cpu(right->bb_rightsib), 0, - &rrbp, XFS_ALLOC_BTREE_REF))) - return error; - rrblock = XFS_BUF_TO_ALLOC_BLOCK(rrbp); - if ((error = xfs_btree_check_sblock(cur, rrblock, level, rrbp))) - return error; - rrblock->bb_leftsib = cpu_to_be32(rbno); - xfs_alloc_log_block(cur->bc_tp, rrbp, XFS_BB_LEFTSIB); - } - /* - * If the cursor is really in the right block, move it there. - * If it's just pointing past the last entry in left, then we'll - * insert there, so don't change anything in that case. - */ - if (cur->bc_ptrs[level] > be16_to_cpu(left->bb_numrecs) + 1) { - xfs_btree_setbuf(cur, level, rbp); - cur->bc_ptrs[level] -= be16_to_cpu(left->bb_numrecs); - } - /* - * If there are more levels, we'll need another cursor which refers to - * the right block, no matter where this cursor was. - */ - if (level + 1 < cur->bc_nlevels) { - if ((error = xfs_btree_dup_cursor(cur, curp))) - return error; - (*curp)->bc_ptrs[level + 1]++; - } - *bnop = rbno; - *stat = 1; - return 0; -} /* * Externally visible routines. @@ -1396,6 +1244,41 @@ xfs_allocbt_dup_cursor( cur->bc_btnum); } +STATIC int +xfs_allocbt_alloc_block( + struct xfs_btree_cur *cur, + union xfs_btree_ptr *start, + union xfs_btree_ptr *new, + int length, + int *stat) +{ + int error; + xfs_agblock_t bno; + + XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY); + + /* Allocate the new block from the freelist. If we can't, give up. */ + error = xfs_alloc_get_freelist(cur->bc_tp, cur->bc_private.a.agbp, + &bno, 1); + if (error) { + XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR); + return error; + } + + if (bno == NULLAGBLOCK) { + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); + *stat = 0; + return 0; + } + + xfs_trans_agbtree_delta(cur->bc_tp, 1); + new->s = cpu_to_be32(bno); + + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); + *stat = 1; + return 0; +} + /* * Update the longest extent in the AGF */ @@ -1557,6 +1440,7 @@ static const struct xfs_btree_ops xfs_allocbt_ops = { .key_len = sizeof(xfs_alloc_key_t), .dup_cursor = xfs_allocbt_dup_cursor, + .alloc_block = xfs_allocbt_alloc_block, .update_lastrec = xfs_allocbt_update_lastrec, .get_maxrecs = xfs_allocbt_get_maxrecs, .init_key_from_rec = xfs_allocbt_init_key_from_rec, -- cgit v1.2.3