Merge git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6
[safe/jmp/linux-2.6] / fs / xfs / xfs_alloc_btree.c
index 818adca..c10c3a2 100644 (file)
 #include "xfs_alloc.h"
 #include "xfs_error.h"
 
-/*
- * Prototypes for internal functions.
- */
-
-STATIC void xfs_alloc_log_block(xfs_trans_t *, xfs_buf_t *, int);
-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);
-
-/*
- * Internal functions.
- */
-
-/*
- * Single level of the xfs_alloc_delete record deletion routine.
- * Delete record pointed to by cur/level.
- * Remove the record from its block then rebalance the tree.
- * Return 0 for error, 1 for done, 2 to go on to the next level.
- */
-STATIC int                             /* error */
-xfs_alloc_delrec(
-       xfs_btree_cur_t         *cur,   /* btree cursor */
-       int                     level,  /* level removing record from */
-       int                     *stat)  /* fail/done/go-on */
-{
-       xfs_agf_t               *agf;   /* allocation group freelist header */
-       xfs_alloc_block_t       *block; /* btree block record/key lives in */
-       xfs_agblock_t           bno;    /* btree block number */
-       xfs_buf_t               *bp;    /* buffer for block */
-       int                     error;  /* error return value */
-       int                     i;      /* loop index */
-       xfs_alloc_key_t         key;    /* kp points here if block is level 0 */
-       xfs_agblock_t           lbno;   /* left block's block number */
-       xfs_buf_t               *lbp;   /* left block's buffer pointer */
-       xfs_alloc_block_t       *left;  /* left btree block */
-       xfs_alloc_key_t         *lkp=NULL;      /* left block key pointer */
-       xfs_alloc_ptr_t         *lpp=NULL;      /* left block address pointer */
-       int                     lrecs=0;        /* number of records in left block */
-       xfs_alloc_rec_t         *lrp;   /* left block record pointer */
-       xfs_mount_t             *mp;    /* mount structure */
-       int                     ptr;    /* index in btree block for this rec */
-       xfs_agblock_t           rbno;   /* right block's block number */
-       xfs_buf_t               *rbp;   /* right block's buffer pointer */
-       xfs_alloc_block_t       *right; /* right btree block */
-       xfs_alloc_key_t         *rkp;   /* right block key pointer */
-       xfs_alloc_ptr_t         *rpp;   /* right block address pointer */
-       int                     rrecs=0;        /* number of records in right block */
-       int                     numrecs;
-       xfs_alloc_rec_t         *rrp;   /* right block record pointer */
-       xfs_btree_cur_t         *tcur;  /* temporary btree cursor */
-
-       /*
-        * Get the index of the entry being deleted, check for nothing there.
-        */
-       ptr = cur->bc_ptrs[level];
-       if (ptr == 0) {
-               *stat = 0;
-               return 0;
-       }
-       /*
-        * Get the buffer & block containing the record or key/ptr.
-        */
-       bp = cur->bc_bufs[level];
-       block = XFS_BUF_TO_ALLOC_BLOCK(bp);
-#ifdef DEBUG
-       if ((error = xfs_btree_check_sblock(cur, block, level, bp)))
-               return error;
-#endif
-       /*
-        * Fail if we're off the end of the block.
-        */
-       numrecs = be16_to_cpu(block->bb_numrecs);
-       if (ptr > numrecs) {
-               *stat = 0;
-               return 0;
-       }
-       XFS_STATS_INC(xs_abt_delrec);
-       /*
-        * It's a nonleaf.  Excise the key and ptr being deleted, by
-        * sliding the entries past them down one.
-        * Log the changed areas of the block.
-        */
-       if (level > 0) {
-               lkp = XFS_ALLOC_KEY_ADDR(block, 1, cur);
-               lpp = XFS_ALLOC_PTR_ADDR(block, 1, cur);
-#ifdef DEBUG
-               for (i = ptr; i < numrecs; i++) {
-                       if ((error = xfs_btree_check_sptr(cur, be32_to_cpu(lpp[i]), level)))
-                               return error;
-               }
-#endif
-               if (ptr < numrecs) {
-                       memmove(&lkp[ptr - 1], &lkp[ptr],
-                               (numrecs - ptr) * sizeof(*lkp));
-                       memmove(&lpp[ptr - 1], &lpp[ptr],
-                               (numrecs - ptr) * sizeof(*lpp));
-                       xfs_alloc_log_ptrs(cur, bp, ptr, numrecs - 1);
-                       xfs_alloc_log_keys(cur, bp, ptr, numrecs - 1);
-               }
-       }
-       /*
-        * It's a leaf.  Excise the record being deleted, by sliding the
-        * entries past it down one.  Log the changed areas of the block.
-        */
-       else {
-               lrp = XFS_ALLOC_REC_ADDR(block, 1, cur);
-               if (ptr < numrecs) {
-                       memmove(&lrp[ptr - 1], &lrp[ptr],
-                               (numrecs - ptr) * sizeof(*lrp));
-                       xfs_alloc_log_recs(cur, bp, ptr, numrecs - 1);
-               }
-               /*
-                * If it's the first record in the block, we'll need a key
-                * structure to pass up to the next level (updkey).
-                */
-               if (ptr == 1) {
-                       key.ar_startblock = lrp->ar_startblock;
-                       key.ar_blockcount = lrp->ar_blockcount;
-                       lkp = &key;
-               }
-       }
-       /*
-        * Decrement and log the number of entries in the block.
-        */
-       numrecs--;
-       block->bb_numrecs = cpu_to_be16(numrecs);
-       xfs_alloc_log_block(cur->bc_tp, bp, XFS_BB_NUMRECS);
-       /*
-        * See if the longest free extent in the allocation group was
-        * changed by this operation.  True if it's the by-size btree, and
-        * this is the leaf level, and there is no right sibling block,
-        * and this was the last record.
-        */
-       agf = XFS_BUF_TO_AGF(cur->bc_private.a.agbp);
-       mp = cur->bc_mp;
-
-       if (level == 0 &&
-           cur->bc_btnum == XFS_BTNUM_CNT &&
-           be32_to_cpu(block->bb_rightsib) == NULLAGBLOCK &&
-           ptr > numrecs) {
-               ASSERT(ptr == numrecs + 1);
-               /*
-                * There are still records in the block.  Grab the size
-                * from the last one.
-                */
-               if (numrecs) {
-                       rrp = XFS_ALLOC_REC_ADDR(block, numrecs, cur);
-                       agf->agf_longest = rrp->ar_blockcount;
-               }
-               /*
-                * No free extents left.
-                */
-               else
-                       agf->agf_longest = 0;
-               mp->m_perag[be32_to_cpu(agf->agf_seqno)].pagf_longest =
-                       be32_to_cpu(agf->agf_longest);
-               xfs_alloc_log_agf(cur->bc_tp, cur->bc_private.a.agbp,
-                       XFS_AGF_LONGEST);
-       }
-       /*
-        * Is this the root level?  If so, we're almost done.
-        */
-       if (level == cur->bc_nlevels - 1) {
-               /*
-                * If this is the root level,
-                * and there's only one entry left,
-                * and it's NOT the leaf level,
-                * then we can get rid of this level.
-                */
-               if (numrecs == 1 && level > 0) {
-                       /*
-                        * lpp is still set to the first pointer in the block.
-                        * Make it the new root of the btree.
-                        */
-                       bno = be32_to_cpu(agf->agf_roots[cur->bc_btnum]);
-                       agf->agf_roots[cur->bc_btnum] = *lpp;
-                       be32_add_cpu(&agf->agf_levels[cur->bc_btnum], -1);
-                       mp->m_perag[be32_to_cpu(agf->agf_seqno)].pagf_levels[cur->bc_btnum]--;
-                       /*
-                        * Put this buffer/block on the ag's freelist.
-                        */
-                       error = xfs_alloc_put_freelist(cur->bc_tp,
-                                       cur->bc_private.a.agbp, NULL, bno, 1);
-                       if (error)
-                               return error;
-                       /*
-                        * Since blocks move to the free list without the
-                        * coordination used in xfs_bmap_finish, we can't allow
-                        * block to be available for reallocation and
-                        * non-transaction writing (user data) until we know
-                        * that the transaction that moved it to the free list
-                        * is permanently on disk. We track the blocks by
-                        * declaring these blocks as "busy"; the busy list is
-                        * maintained on a per-ag basis and each transaction
-                        * records which entries should be removed when the
-                        * iclog commits to disk. If a busy block is
-                        * allocated, the iclog is pushed up to the LSN
-                        * that freed the block.
-                        */
-                       xfs_alloc_mark_busy(cur->bc_tp,
-                               be32_to_cpu(agf->agf_seqno), bno, 1);
-
-                       xfs_trans_agbtree_delta(cur->bc_tp, -1);
-                       xfs_alloc_log_agf(cur->bc_tp, cur->bc_private.a.agbp,
-                               XFS_AGF_ROOTS | XFS_AGF_LEVELS);
-                       /*
-                        * Update the cursor so there's one fewer level.
-                        */
-                       xfs_btree_setbuf(cur, level, NULL);
-                       cur->bc_nlevels--;
-               } else if (level > 0 &&
-                          (error = xfs_btree_decrement(cur, level, &i)))
-                       return error;
-               *stat = 1;
-               return 0;
-       }
-       /*
-        * If we deleted the leftmost entry in the block, update the
-        * key values above us in the tree.
-        */
-       if (ptr == 1 && (error = xfs_btree_updkey(cur, (union xfs_btree_key *)lkp, level + 1)))
-               return error;
-       /*
-        * If the number of records remaining in the block is at least
-        * the minimum, we're done.
-        */
-       if (numrecs >= XFS_ALLOC_BLOCK_MINRECS(level, cur)) {
-               if (level > 0 && (error = xfs_btree_decrement(cur, level, &i)))
-                       return error;
-               *stat = 1;
-               return 0;
-       }
-       /*
-        * Otherwise, we have to move some records around to keep the
-        * tree balanced.  Look at the left and right sibling blocks to
-        * see if we can re-balance by moving only one record.
-        */
-       rbno = be32_to_cpu(block->bb_rightsib);
-       lbno = be32_to_cpu(block->bb_leftsib);
-       bno = NULLAGBLOCK;
-       ASSERT(rbno != NULLAGBLOCK || lbno != NULLAGBLOCK);
-       /*
-        * Duplicate the cursor so our btree manipulations here won't
-        * disrupt the next level up.
-        */
-       if ((error = xfs_btree_dup_cursor(cur, &tcur)))
-               return error;
-       /*
-        * If there's a right sibling, see if it's ok to shift an entry
-        * out of it.
-        */
-       if (rbno != NULLAGBLOCK) {
-               /*
-                * Move the temp cursor to the last entry in the next block.
-                * Actually any entry but the first would suffice.
-                */
-               i = xfs_btree_lastrec(tcur, level);
-               XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
-               if ((error = xfs_btree_increment(tcur, level, &i)))
-                       goto error0;
-               XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
-               i = xfs_btree_lastrec(tcur, level);
-               XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
-               /*
-                * Grab a pointer to the block.
-                */
-               rbp = tcur->bc_bufs[level];
-               right = XFS_BUF_TO_ALLOC_BLOCK(rbp);
-#ifdef DEBUG
-               if ((error = xfs_btree_check_sblock(cur, right, level, rbp)))
-                       goto error0;
-#endif
-               /*
-                * Grab the current block number, for future use.
-                */
-               bno = be32_to_cpu(right->bb_leftsib);
-               /*
-                * If right block is full enough so that removing one entry
-                * won't make it too empty, and left-shifting an entry out
-                * of right to us works, we're done.
-                */
-               if (be16_to_cpu(right->bb_numrecs) - 1 >=
-                    XFS_ALLOC_BLOCK_MINRECS(level, cur)) {
-                       if ((error = xfs_btree_lshift(tcur, level, &i)))
-                               goto error0;
-                       if (i) {
-                               ASSERT(be16_to_cpu(block->bb_numrecs) >=
-                                      XFS_ALLOC_BLOCK_MINRECS(level, cur));
-                               xfs_btree_del_cursor(tcur,
-                                                    XFS_BTREE_NOERROR);
-                               if (level > 0 &&
-                                   (error = xfs_btree_decrement(cur, level,
-                                           &i)))
-                                       return error;
-                               *stat = 1;
-                               return 0;
-                       }
-               }
-               /*
-                * Otherwise, grab the number of records in right for
-                * future reference, and fix up the temp cursor to point
-                * to our block again (last record).
-                */
-               rrecs = be16_to_cpu(right->bb_numrecs);
-               if (lbno != NULLAGBLOCK) {
-                       i = xfs_btree_firstrec(tcur, level);
-                       XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
-                       if ((error = xfs_btree_decrement(tcur, level, &i)))
-                               goto error0;
-                       XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
-               }
-       }
-       /*
-        * If there's a left sibling, see if it's ok to shift an entry
-        * out of it.
-        */
-       if (lbno != NULLAGBLOCK) {
-               /*
-                * Move the temp cursor to the first entry in the
-                * previous block.
-                */
-               i = xfs_btree_firstrec(tcur, level);
-               XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
-               if ((error = xfs_btree_decrement(tcur, level, &i)))
-                       goto error0;
-               XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
-               xfs_btree_firstrec(tcur, level);
-               /*
-                * Grab a pointer to the block.
-                */
-               lbp = tcur->bc_bufs[level];
-               left = XFS_BUF_TO_ALLOC_BLOCK(lbp);
-#ifdef DEBUG
-               if ((error = xfs_btree_check_sblock(cur, left, level, lbp)))
-                       goto error0;
-#endif
-               /*
-                * Grab the current block number, for future use.
-                */
-               bno = be32_to_cpu(left->bb_rightsib);
-               /*
-                * If left block is full enough so that removing one entry
-                * won't make it too empty, and right-shifting an entry out
-                * of left to us works, we're done.
-                */
-               if (be16_to_cpu(left->bb_numrecs) - 1 >=
-                    XFS_ALLOC_BLOCK_MINRECS(level, cur)) {
-                       if ((error = xfs_btree_rshift(tcur, level, &i)))
-                               goto error0;
-                       if (i) {
-                               ASSERT(be16_to_cpu(block->bb_numrecs) >=
-                                      XFS_ALLOC_BLOCK_MINRECS(level, cur));
-                               xfs_btree_del_cursor(tcur,
-                                                    XFS_BTREE_NOERROR);
-                               if (level == 0)
-                                       cur->bc_ptrs[0]++;
-                               *stat = 1;
-                               return 0;
-                       }
-               }
-               /*
-                * Otherwise, grab the number of records in right for
-                * future reference.
-                */
-               lrecs = be16_to_cpu(left->bb_numrecs);
-       }
-       /*
-        * Delete the temp cursor, we're done with it.
-        */
-       xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
-       /*
-        * If here, we need to do a join to keep the tree balanced.
-        */
-       ASSERT(bno != NULLAGBLOCK);
-       /*
-        * See if we can join with the left neighbor block.
-        */
-       if (lbno != NULLAGBLOCK &&
-           lrecs + numrecs <= XFS_ALLOC_BLOCK_MAXRECS(level, cur)) {
-               /*
-                * Set "right" to be the starting block,
-                * "left" to be the left neighbor.
-                */
-               rbno = bno;
-               right = block;
-               rrecs = be16_to_cpu(right->bb_numrecs);
-               rbp = bp;
-               if ((error = xfs_btree_read_bufs(mp, cur->bc_tp,
-                               cur->bc_private.a.agno, lbno, 0, &lbp,
-                               XFS_ALLOC_BTREE_REF)))
-                       return error;
-               left = XFS_BUF_TO_ALLOC_BLOCK(lbp);
-               lrecs = be16_to_cpu(left->bb_numrecs);
-               if ((error = xfs_btree_check_sblock(cur, left, level, lbp)))
-                       return error;
-       }
-       /*
-        * If that won't work, see if we can join with the right neighbor block.
-        */
-       else if (rbno != NULLAGBLOCK &&
-                rrecs + numrecs <= XFS_ALLOC_BLOCK_MAXRECS(level, cur)) {
-               /*
-                * Set "left" to be the starting block,
-                * "right" to be the right neighbor.
-                */
-               lbno = bno;
-               left = block;
-               lrecs = be16_to_cpu(left->bb_numrecs);
-               lbp = bp;
-               if ((error = xfs_btree_read_bufs(mp, cur->bc_tp,
-                               cur->bc_private.a.agno, rbno, 0, &rbp,
-                               XFS_ALLOC_BTREE_REF)))
-                       return error;
-               right = XFS_BUF_TO_ALLOC_BLOCK(rbp);
-               rrecs = be16_to_cpu(right->bb_numrecs);
-               if ((error = xfs_btree_check_sblock(cur, right, level, rbp)))
-                       return error;
-       }
-       /*
-        * Otherwise, we can't fix the imbalance.
-        * Just return.  This is probably a logic error, but it's not fatal.
-        */
-       else {
-               if (level > 0 && (error = xfs_btree_decrement(cur, level, &i)))
-                       return error;
-               *stat = 1;
-               return 0;
-       }
-       /*
-        * We're now going to join "left" and "right" by moving all the stuff
-        * in "right" to "left" and deleting "right".
-        */
-       if (level > 0) {
-               /*
-                * It's a non-leaf.  Move keys and pointers.
-                */
-               lkp = XFS_ALLOC_KEY_ADDR(left, lrecs + 1, cur);
-               lpp = XFS_ALLOC_PTR_ADDR(left, lrecs + 1, cur);
-               rkp = XFS_ALLOC_KEY_ADDR(right, 1, cur);
-               rpp = XFS_ALLOC_PTR_ADDR(right, 1, cur);
-#ifdef DEBUG
-               for (i = 0; i < rrecs; i++) {
-                       if ((error = xfs_btree_check_sptr(cur, be32_to_cpu(rpp[i]), level)))
-                               return error;
-               }
-#endif
-               memcpy(lkp, rkp, rrecs * sizeof(*lkp));
-               memcpy(lpp, rpp, rrecs * sizeof(*lpp));
-               xfs_alloc_log_keys(cur, lbp, lrecs + 1, lrecs + rrecs);
-               xfs_alloc_log_ptrs(cur, lbp, lrecs + 1, lrecs + rrecs);
-       } else {
-               /*
-                * It's a leaf.  Move records.
-                */
-               lrp = XFS_ALLOC_REC_ADDR(left, lrecs + 1, cur);
-               rrp = XFS_ALLOC_REC_ADDR(right, 1, cur);
-               memcpy(lrp, rrp, rrecs * sizeof(*lrp));
-               xfs_alloc_log_recs(cur, lbp, lrecs + 1, lrecs + rrecs);
-       }
-       /*
-        * If we joined with the left neighbor, set the buffer in the
-        * cursor to the left block, and fix up the index.
-        */
-       if (bp != lbp) {
-               xfs_btree_setbuf(cur, level, lbp);
-               cur->bc_ptrs[level] += lrecs;
-       }
-       /*
-        * If we joined with the right neighbor and there's a level above
-        * us, increment the cursor at that level.
-        */
-       else if (level + 1 < cur->bc_nlevels &&
-                (error = xfs_btree_increment(cur, level + 1, &i)))
-               return error;
-       /*
-        * Fix up the number of records in the surviving block.
-        */
-       lrecs += rrecs;
-       left->bb_numrecs = cpu_to_be16(lrecs);
-       /*
-        * Fix up the right block pointer in the surviving block, and log it.
-        */
-       left->bb_rightsib = right->bb_rightsib;
-       xfs_alloc_log_block(cur->bc_tp, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
-       /*
-        * If there is a right sibling now, make it point to the
-        * remaining block.
-        */
-       if (be32_to_cpu(left->bb_rightsib) != NULLAGBLOCK) {
-               xfs_alloc_block_t       *rrblock;
-               xfs_buf_t               *rrbp;
-
-               if ((error = xfs_btree_read_bufs(mp, cur->bc_tp,
-                               cur->bc_private.a.agno, be32_to_cpu(left->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(lbno);
-               xfs_alloc_log_block(cur->bc_tp, rrbp, XFS_BB_LEFTSIB);
-       }
-       /*
-        * Free the deleting block by putting it on the freelist.
-        */
-       error = xfs_alloc_put_freelist(cur->bc_tp,
-                                        cur->bc_private.a.agbp, NULL, rbno, 1);
-       if (error)
-               return error;
-       /*
-        * Since blocks move to the free list without the coordination
-        * used in xfs_bmap_finish, we can't allow block to be available
-        * for reallocation and non-transaction writing (user data)
-        * until we know that the transaction that moved it to the free
-        * list is permanently on disk. We track the blocks by declaring
-        * these blocks as "busy"; the busy list is maintained on a
-        * per-ag basis and each transaction records which entries
-        * should be removed when the iclog commits to disk. If a
-        * busy block is allocated, the iclog is pushed up to the
-        * LSN that freed the block.
-        */
-       xfs_alloc_mark_busy(cur->bc_tp, be32_to_cpu(agf->agf_seqno), bno, 1);
-       xfs_trans_agbtree_delta(cur->bc_tp, -1);
-
-       /*
-        * Adjust the current level's cursor so that we're left referring
-        * to the right node, after we're done.
-        * If this leaves the ptr value 0 our caller will fix it up.
-        */
-       if (level > 0)
-               cur->bc_ptrs[level]--;
-       /*
-        * Return value means the next level up has something to do.
-        */
-       *stat = 2;
-       return 0;
-
-error0:
-       xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
-       return error;
-}
-
-/*
- * Log header fields from a btree block.
- */
-STATIC void
-xfs_alloc_log_block(
-       xfs_trans_t             *tp,    /* transaction pointer */
-       xfs_buf_t               *bp,    /* buffer containing btree block */
-       int                     fields) /* mask of fields: XFS_BB_... */
-{
-       int                     first;  /* first byte offset logged */
-       int                     last;   /* last byte offset logged */
-       static const short      offsets[] = {   /* table of offsets */
-               offsetof(xfs_alloc_block_t, bb_magic),
-               offsetof(xfs_alloc_block_t, bb_level),
-               offsetof(xfs_alloc_block_t, bb_numrecs),
-               offsetof(xfs_alloc_block_t, bb_leftsib),
-               offsetof(xfs_alloc_block_t, bb_rightsib),
-               sizeof(xfs_alloc_block_t)
-       };
-
-       xfs_btree_offsets(fields, offsets, XFS_BB_NUM_BITS, &first, &last);
-       xfs_trans_log_buf(tp, bp, first, last);
-}
-
-/*
- * Log keys from a btree block (nonleaf).
- */
-STATIC void
-xfs_alloc_log_keys(
-       xfs_btree_cur_t         *cur,   /* btree cursor */
-       xfs_buf_t               *bp,    /* buffer containing btree block */
-       int                     kfirst, /* index of first key to log */
-       int                     klast)  /* index of last key to log */
-{
-       xfs_alloc_block_t       *block; /* btree block to log from */
-       int                     first;  /* first byte offset logged */
-       xfs_alloc_key_t         *kp;    /* key pointer in btree block */
-       int                     last;   /* last byte offset logged */
-
-       block = XFS_BUF_TO_ALLOC_BLOCK(bp);
-       kp = XFS_ALLOC_KEY_ADDR(block, 1, cur);
-       first = (int)((xfs_caddr_t)&kp[kfirst - 1] - (xfs_caddr_t)block);
-       last = (int)(((xfs_caddr_t)&kp[klast] - 1) - (xfs_caddr_t)block);
-       xfs_trans_log_buf(cur->bc_tp, bp, first, last);
-}
-
-/*
- * Log block pointer fields from a btree block (nonleaf).
- */
-STATIC void
-xfs_alloc_log_ptrs(
-       xfs_btree_cur_t         *cur,   /* btree cursor */
-       xfs_buf_t               *bp,    /* buffer containing btree block */
-       int                     pfirst, /* index of first pointer to log */
-       int                     plast)  /* index of last pointer to log */
-{
-       xfs_alloc_block_t       *block; /* btree block to log from */
-       int                     first;  /* first byte offset logged */
-       int                     last;   /* last byte offset logged */
-       xfs_alloc_ptr_t         *pp;    /* block-pointer pointer in btree blk */
-
-       block = XFS_BUF_TO_ALLOC_BLOCK(bp);
-       pp = XFS_ALLOC_PTR_ADDR(block, 1, cur);
-       first = (int)((xfs_caddr_t)&pp[pfirst - 1] - (xfs_caddr_t)block);
-       last = (int)(((xfs_caddr_t)&pp[plast] - 1) - (xfs_caddr_t)block);
-       xfs_trans_log_buf(cur->bc_tp, bp, first, last);
-}
-
-/*
- * Log records from a btree block (leaf).
- */
-STATIC void
-xfs_alloc_log_recs(
-       xfs_btree_cur_t         *cur,   /* btree cursor */
-       xfs_buf_t               *bp,    /* buffer containing btree block */
-       int                     rfirst, /* index of first record to log */
-       int                     rlast)  /* index of last record to log */
-{
-       xfs_alloc_block_t       *block; /* btree block to log from */
-       int                     first;  /* first byte offset logged */
-       int                     last;   /* last byte offset logged */
-       xfs_alloc_rec_t         *rp;    /* record pointer for btree block */
-
-
-       block = XFS_BUF_TO_ALLOC_BLOCK(bp);
-       rp = XFS_ALLOC_REC_ADDR(block, 1, cur);
-#ifdef DEBUG
-       {
-               xfs_agf_t       *agf;
-               xfs_alloc_rec_t *p;
-
-               agf = XFS_BUF_TO_AGF(cur->bc_private.a.agbp);
-               for (p = &rp[rfirst - 1]; p <= &rp[rlast - 1]; p++)
-                       ASSERT(be32_to_cpu(p->ar_startblock) +
-                              be32_to_cpu(p->ar_blockcount) <=
-                              be32_to_cpu(agf->agf_length));
-       }
-#endif
-       first = (int)((xfs_caddr_t)&rp[rfirst - 1] - (xfs_caddr_t)block);
-       last = (int)(((xfs_caddr_t)&rp[rlast] - 1) - (xfs_caddr_t)block);
-       xfs_trans_log_buf(cur->bc_tp, bp, first, last);
-}
-
-
-/*
- * Externally visible routines.
- */
-
-/*
- * Delete the record pointed to by cur.
- * The cursor refers to the place where the record was (could be inserted)
- * when the operation returns.
- */
-int                                    /* error */
-xfs_alloc_delete(
-       xfs_btree_cur_t *cur,           /* btree cursor */
-       int             *stat)          /* success/failure */
-{
-       int             error;          /* error return value */
-       int             i;              /* result code */
-       int             level;          /* btree level */
-
-       /*
-        * Go up the tree, starting at leaf level.
-        * If 2 is returned then a join was done; go to the next level.
-        * Otherwise we are done.
-        */
-       for (level = 0, i = 2; i == 2; level++) {
-               if ((error = xfs_alloc_delrec(cur, level, &i)))
-                       return error;
-       }
-       if (i == 0) {
-               for (level = 1; level < cur->bc_nlevels; level++) {
-                       if (cur->bc_ptrs[level] == 0) {
-                               if ((error = xfs_btree_decrement(cur, level, &i)))
-                                       return error;
-                               break;
-                       }
-               }
-       }
-       *stat = i;
-       return 0;
-}
-
-/*
- * Get the data from the pointed-to record.
- */
-int                                    /* error */
-xfs_alloc_get_rec(
-       xfs_btree_cur_t         *cur,   /* btree cursor */
-       xfs_agblock_t           *bno,   /* output: starting block of extent */
-       xfs_extlen_t            *len,   /* output: length of extent */
-       int                     *stat)  /* output: success/failure */
-{
-       xfs_alloc_block_t       *block; /* btree block */
-#ifdef DEBUG
-       int                     error;  /* error return value */
-#endif
-       int                     ptr;    /* record number */
-
-       ptr = cur->bc_ptrs[0];
-       block = XFS_BUF_TO_ALLOC_BLOCK(cur->bc_bufs[0]);
-#ifdef DEBUG
-       if ((error = xfs_btree_check_sblock(cur, block, 0, cur->bc_bufs[0])))
-               return error;
-#endif
-       /*
-        * Off the right end or left end, return failure.
-        */
-       if (ptr > be16_to_cpu(block->bb_numrecs) || ptr <= 0) {
-               *stat = 0;
-               return 0;
-       }
-       /*
-        * Point to the record and extract its data.
-        */
-       {
-               xfs_alloc_rec_t         *rec;   /* record data */
-
-               rec = XFS_ALLOC_REC_ADDR(block, ptr, cur);
-               *bno = be32_to_cpu(rec->ar_startblock);
-               *len = be32_to_cpu(rec->ar_blockcount);
-       }
-       *stat = 1;
-       return 0;
-}
-
 
 STATIC struct xfs_btree_cur *
 xfs_allocbt_dup_cursor(
@@ -834,6 +105,37 @@ xfs_allocbt_alloc_block(
        return 0;
 }
 
+STATIC int
+xfs_allocbt_free_block(
+       struct xfs_btree_cur    *cur,
+       struct xfs_buf          *bp)
+{
+       struct xfs_buf          *agbp = cur->bc_private.a.agbp;
+       struct xfs_agf          *agf = XFS_BUF_TO_AGF(agbp);
+       xfs_agblock_t           bno;
+       int                     error;
+
+       bno = xfs_daddr_to_agbno(cur->bc_mp, XFS_BUF_ADDR(bp));
+       error = xfs_alloc_put_freelist(cur->bc_tp, agbp, NULL, bno, 1);
+       if (error)
+               return error;
+
+       /*
+        * Since blocks move to the free list without the coordination used in
+        * xfs_bmap_finish, we can't allow block to be available for
+        * reallocation and non-transaction writing (user data) until we know
+        * that the transaction that moved it to the free list is permanently
+        * on disk. We track the blocks by declaring these blocks as "busy";
+        * the busy list is maintained on a per-ag basis and each transaction
+        * records which entries should be removed when the iclog commits to
+        * disk. If a busy block is allocated, the iclog is pushed up to the
+        * LSN that freed the block.
+        */
+       xfs_alloc_mark_busy(cur->bc_tp, be32_to_cpu(agf->agf_seqno), bno, 1);
+       xfs_trans_agbtree_delta(cur->bc_tp, -1);
+       return 0;
+}
+
 /*
  * Update the longest extent in the AGF
  */
@@ -848,6 +150,7 @@ xfs_allocbt_update_lastrec(
        struct xfs_agf          *agf = XFS_BUF_TO_AGF(cur->bc_private.a.agbp);
        xfs_agnumber_t          seqno = be32_to_cpu(agf->agf_seqno);
        __be32                  len;
+       int                     numrecs;
 
        ASSERT(cur->bc_btnum == XFS_BTNUM_CNT);
 
@@ -867,6 +170,22 @@ xfs_allocbt_update_lastrec(
                        return;
                len = rec->alloc.ar_blockcount;
                break;
+       case LASTREC_DELREC:
+               numrecs = xfs_btree_get_numrecs(block);
+               if (ptr <= numrecs)
+                       return;
+               ASSERT(ptr == numrecs + 1);
+
+               if (numrecs) {
+                       xfs_alloc_rec_t *rrp;
+
+                       rrp = XFS_ALLOC_REC_ADDR(cur->bc_mp, block, numrecs);
+                       len = rrp->ar_blockcount;
+               } else {
+                       len = 0;
+               }
+
+               break;
        default:
                ASSERT(0);
                return;
@@ -878,6 +197,14 @@ xfs_allocbt_update_lastrec(
 }
 
 STATIC int
+xfs_allocbt_get_minrecs(
+       struct xfs_btree_cur    *cur,
+       int                     level)
+{
+       return cur->bc_mp->m_alloc_mnr[level != 0];
+}
+
+STATIC int
 xfs_allocbt_get_maxrecs(
        struct xfs_btree_cur    *cur,
        int                     level)
@@ -952,6 +279,77 @@ xfs_allocbt_key_diff(
        return (__int64_t)be32_to_cpu(kp->ar_startblock) - rec->ar_startblock;
 }
 
+STATIC int
+xfs_allocbt_kill_root(
+       struct xfs_btree_cur    *cur,
+       struct xfs_buf          *bp,
+       int                     level,
+       union xfs_btree_ptr     *newroot)
+{
+       int                     error;
+
+       XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
+       XFS_BTREE_STATS_INC(cur, killroot);
+
+       /*
+        * Update the root pointer, decreasing the level by 1 and then
+        * free the old root.
+        */
+       xfs_allocbt_set_root(cur, newroot, -1);
+       error = xfs_allocbt_free_block(cur, bp);
+       if (error) {
+               XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
+               return error;
+       }
+
+       XFS_BTREE_STATS_INC(cur, free);
+
+       xfs_btree_setbuf(cur, level, NULL);
+       cur->bc_nlevels--;
+
+       XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
+       return 0;
+}
+
+#ifdef DEBUG
+STATIC int
+xfs_allocbt_keys_inorder(
+       struct xfs_btree_cur    *cur,
+       union xfs_btree_key     *k1,
+       union xfs_btree_key     *k2)
+{
+       if (cur->bc_btnum == XFS_BTNUM_BNO) {
+               return be32_to_cpu(k1->alloc.ar_startblock) <
+                      be32_to_cpu(k2->alloc.ar_startblock);
+       } else {
+               return be32_to_cpu(k1->alloc.ar_blockcount) <
+                       be32_to_cpu(k2->alloc.ar_blockcount) ||
+                       (k1->alloc.ar_blockcount == k2->alloc.ar_blockcount &&
+                        be32_to_cpu(k1->alloc.ar_startblock) <
+                        be32_to_cpu(k2->alloc.ar_startblock));
+       }
+}
+
+STATIC int
+xfs_allocbt_recs_inorder(
+       struct xfs_btree_cur    *cur,
+       union xfs_btree_rec     *r1,
+       union xfs_btree_rec     *r2)
+{
+       if (cur->bc_btnum == XFS_BTNUM_BNO) {
+               return be32_to_cpu(r1->alloc.ar_startblock) +
+                       be32_to_cpu(r1->alloc.ar_blockcount) <=
+                       be32_to_cpu(r2->alloc.ar_startblock);
+       } else {
+               return be32_to_cpu(r1->alloc.ar_blockcount) <
+                       be32_to_cpu(r2->alloc.ar_blockcount) ||
+                       (r1->alloc.ar_blockcount == r2->alloc.ar_blockcount &&
+                        be32_to_cpu(r1->alloc.ar_startblock) <
+                        be32_to_cpu(r2->alloc.ar_startblock));
+       }
+}
+#endif /* DEBUG */
+
 #ifdef XFS_BTREE_TRACE
 ktrace_t       *xfs_allocbt_trace_buf;
 
@@ -1024,8 +422,11 @@ static const struct xfs_btree_ops xfs_allocbt_ops = {
 
        .dup_cursor             = xfs_allocbt_dup_cursor,
        .set_root               = xfs_allocbt_set_root,
+       .kill_root              = xfs_allocbt_kill_root,
        .alloc_block            = xfs_allocbt_alloc_block,
+       .free_block             = xfs_allocbt_free_block,
        .update_lastrec         = xfs_allocbt_update_lastrec,
+       .get_minrecs            = xfs_allocbt_get_minrecs,
        .get_maxrecs            = xfs_allocbt_get_maxrecs,
        .init_key_from_rec      = xfs_allocbt_init_key_from_rec,
        .init_rec_from_key      = xfs_allocbt_init_rec_from_key,
@@ -1033,6 +434,11 @@ static const struct xfs_btree_ops xfs_allocbt_ops = {
        .init_ptr_from_cur      = xfs_allocbt_init_ptr_from_cur,
        .key_diff               = xfs_allocbt_key_diff,
 
+#ifdef DEBUG
+       .keys_inorder           = xfs_allocbt_keys_inorder,
+       .recs_inorder           = xfs_allocbt_recs_inorder,
+#endif
+
 #ifdef XFS_BTREE_TRACE
        .trace_enter            = xfs_allocbt_trace_enter,
        .trace_cursor           = xfs_allocbt_trace_cursor,
@@ -1074,3 +480,19 @@ xfs_allocbt_init_cursor(
 
        return cur;
 }
+
+/*
+ * Calculate number of records in an alloc btree block.
+ */
+int
+xfs_allocbt_maxrecs(
+       struct xfs_mount        *mp,
+       int                     blocklen,
+       int                     leaf)
+{
+       blocklen -= XFS_ALLOC_BLOCK_LEN(mp);
+
+       if (leaf)
+               return blocklen / sizeof(xfs_alloc_rec_t);
+       return blocklen / (sizeof(xfs_alloc_key_t) + sizeof(xfs_alloc_ptr_t));
+}