]> Pileus Git - ~andy/linux/blobdiff - fs/xfs/xfs_alloc_btree.c
[XFS] implement generic xfs_btree_lookup
[~andy/linux] / fs / xfs / xfs_alloc_btree.c
index 6b45481ad5b03aad4dbc286b63cfe1ccee2ca99a..b81fbf1216ed5d75a59ed2f789f13423d50b821e 100644 (file)
@@ -937,223 +937,6 @@ xfs_alloc_log_recs(
        xfs_trans_log_buf(cur->bc_tp, bp, first, last);
 }
 
-/*
- * Lookup the record.  The cursor is made to point to it, based on dir.
- * Return 0 if can't find any such record, 1 for success.
- */
-STATIC int                             /* error */
-xfs_alloc_lookup(
-       xfs_btree_cur_t         *cur,   /* btree cursor */
-       xfs_lookup_t            dir,    /* <=, ==, or >= */
-       int                     *stat)  /* success/failure */
-{
-       xfs_agblock_t           agbno;  /* a.g. relative btree block number */
-       xfs_agnumber_t          agno;   /* allocation group number */
-       xfs_alloc_block_t       *block=NULL;    /* current btree block */
-       int                     diff;   /* difference for the current key */
-       int                     error;  /* error return value */
-       int                     keyno=0;        /* current key number */
-       int                     level;  /* level in the btree */
-       xfs_mount_t             *mp;    /* file system mount point */
-
-       XFS_STATS_INC(xs_abt_lookup);
-       /*
-        * Get the allocation group header, and the root block number.
-        */
-       mp = cur->bc_mp;
-
-       {
-               xfs_agf_t       *agf;   /* a.g. freespace header */
-
-               agf = XFS_BUF_TO_AGF(cur->bc_private.a.agbp);
-               agno = be32_to_cpu(agf->agf_seqno);
-               agbno = be32_to_cpu(agf->agf_roots[cur->bc_btnum]);
-       }
-       /*
-        * Iterate over each level in the btree, starting at the root.
-        * For each level above the leaves, find the key we need, based
-        * on the lookup record, then follow the corresponding block
-        * pointer down to the next level.
-        */
-       for (level = cur->bc_nlevels - 1, diff = 1; level >= 0; level--) {
-               xfs_buf_t       *bp;    /* buffer pointer for btree block */
-               xfs_daddr_t     d;      /* disk address of btree block */
-
-               /*
-                * Get the disk address we're looking for.
-                */
-               d = XFS_AGB_TO_DADDR(mp, agno, agbno);
-               /*
-                * If the old buffer at this level is for a different block,
-                * throw it away, otherwise just use it.
-                */
-               bp = cur->bc_bufs[level];
-               if (bp && XFS_BUF_ADDR(bp) != d)
-                       bp = NULL;
-               if (!bp) {
-                       /*
-                        * Need to get a new buffer.  Read it, then
-                        * set it in the cursor, releasing the old one.
-                        */
-                       if ((error = xfs_btree_read_bufs(mp, cur->bc_tp, agno,
-                                       agbno, 0, &bp, XFS_ALLOC_BTREE_REF)))
-                               return error;
-                       xfs_btree_setbuf(cur, level, bp);
-                       /*
-                        * Point to the btree block, now that we have the buffer
-                        */
-                       block = XFS_BUF_TO_ALLOC_BLOCK(bp);
-                       if ((error = xfs_btree_check_sblock(cur, block, level,
-                                       bp)))
-                               return error;
-               } else
-                       block = XFS_BUF_TO_ALLOC_BLOCK(bp);
-               /*
-                * If we already had a key match at a higher level, we know
-                * we need to use the first entry in this block.
-                */
-               if (diff == 0)
-                       keyno = 1;
-               /*
-                * Otherwise we need to search this block.  Do a binary search.
-                */
-               else {
-                       int             high;   /* high entry number */
-                       xfs_alloc_key_t *kkbase=NULL;/* base of keys in block */
-                       xfs_alloc_rec_t *krbase=NULL;/* base of records in block */
-                       int             low;    /* low entry number */
-
-                       /*
-                        * Get a pointer to keys or records.
-                        */
-                       if (level > 0)
-                               kkbase = XFS_ALLOC_KEY_ADDR(block, 1, cur);
-                       else
-                               krbase = XFS_ALLOC_REC_ADDR(block, 1, cur);
-                       /*
-                        * Set low and high entry numbers, 1-based.
-                        */
-                       low = 1;
-                       if (!(high = be16_to_cpu(block->bb_numrecs))) {
-                               /*
-                                * If the block is empty, the tree must
-                                * be an empty leaf.
-                                */
-                               ASSERT(level == 0 && cur->bc_nlevels == 1);
-                               cur->bc_ptrs[0] = dir != XFS_LOOKUP_LE;
-                               *stat = 0;
-                               return 0;
-                       }
-                       /*
-                        * Binary search the block.
-                        */
-                       while (low <= high) {
-                               xfs_extlen_t    blockcount;     /* key value */
-                               xfs_agblock_t   startblock;     /* key value */
-
-                               XFS_STATS_INC(xs_abt_compare);
-                               /*
-                                * keyno is average of low and high.
-                                */
-                               keyno = (low + high) >> 1;
-                               /*
-                                * Get startblock & blockcount.
-                                */
-                               if (level > 0) {
-                                       xfs_alloc_key_t *kkp;
-
-                                       kkp = kkbase + keyno - 1;
-                                       startblock = be32_to_cpu(kkp->ar_startblock);
-                                       blockcount = be32_to_cpu(kkp->ar_blockcount);
-                               } else {
-                                       xfs_alloc_rec_t *krp;
-
-                                       krp = krbase + keyno - 1;
-                                       startblock = be32_to_cpu(krp->ar_startblock);
-                                       blockcount = be32_to_cpu(krp->ar_blockcount);
-                               }
-                               /*
-                                * Compute difference to get next direction.
-                                */
-                               if (cur->bc_btnum == XFS_BTNUM_BNO)
-                                       diff = (int)startblock -
-                                              (int)cur->bc_rec.a.ar_startblock;
-                               else if (!(diff = (int)blockcount -
-                                           (int)cur->bc_rec.a.ar_blockcount))
-                                       diff = (int)startblock -
-                                           (int)cur->bc_rec.a.ar_startblock;
-                               /*
-                                * Less than, move right.
-                                */
-                               if (diff < 0)
-                                       low = keyno + 1;
-                               /*
-                                * Greater than, move left.
-                                */
-                               else if (diff > 0)
-                                       high = keyno - 1;
-                               /*
-                                * Equal, we're done.
-                                */
-                               else
-                                       break;
-                       }
-               }
-               /*
-                * If there are more levels, set up for the next level
-                * by getting the block number and filling in the cursor.
-                */
-               if (level > 0) {
-                       /*
-                        * If we moved left, need the previous key number,
-                        * unless there isn't one.
-                        */
-                       if (diff > 0 && --keyno < 1)
-                               keyno = 1;
-                       agbno = be32_to_cpu(*XFS_ALLOC_PTR_ADDR(block, keyno, cur));
-#ifdef DEBUG
-                       if ((error = xfs_btree_check_sptr(cur, agbno, level)))
-                               return error;
-#endif
-                       cur->bc_ptrs[level] = keyno;
-               }
-       }
-       /*
-        * Done with the search.
-        * See if we need to adjust the results.
-        */
-       if (dir != XFS_LOOKUP_LE && diff < 0) {
-               keyno++;
-               /*
-                * If ge search and we went off the end of the block, but it's
-                * not the last block, we're in the wrong block.
-                */
-               if (dir == XFS_LOOKUP_GE &&
-                   keyno > be16_to_cpu(block->bb_numrecs) &&
-                   be32_to_cpu(block->bb_rightsib) != NULLAGBLOCK) {
-                       int     i;
-
-                       cur->bc_ptrs[0] = keyno;
-                       if ((error = xfs_btree_increment(cur, 0, &i)))
-                               return error;
-                       XFS_WANT_CORRUPTED_RETURN(i == 1);
-                       *stat = 1;
-                       return 0;
-               }
-       }
-       else if (dir == XFS_LOOKUP_LE && diff > 0)
-               keyno--;
-       cur->bc_ptrs[0] = keyno;
-       /*
-        * Return if we succeeded or not.
-        */
-       if (keyno == 0 || keyno > be16_to_cpu(block->bb_numrecs))
-               *stat = 0;
-       else
-               *stat = ((dir != XFS_LOOKUP_EQ) || (diff == 0));
-       return 0;
-}
-
 /*
  * Move 1 record left from cur/level if possible.
  * Update cur to reflect the new path.
@@ -1918,53 +1701,6 @@ xfs_alloc_insert(
        return 0;
 }
 
-/*
- * Lookup the record equal to [bno, len] in the btree given by cur.
- */
-int                                    /* error */
-xfs_alloc_lookup_eq(
-       xfs_btree_cur_t *cur,           /* btree cursor */
-       xfs_agblock_t   bno,            /* starting block of extent */
-       xfs_extlen_t    len,            /* length of extent */
-       int             *stat)          /* success/failure */
-{
-       cur->bc_rec.a.ar_startblock = bno;
-       cur->bc_rec.a.ar_blockcount = len;
-       return xfs_alloc_lookup(cur, XFS_LOOKUP_EQ, stat);
-}
-
-/*
- * Lookup the first record greater than or equal to [bno, len]
- * in the btree given by cur.
- */
-int                                    /* error */
-xfs_alloc_lookup_ge(
-       xfs_btree_cur_t *cur,           /* btree cursor */
-       xfs_agblock_t   bno,            /* starting block of extent */
-       xfs_extlen_t    len,            /* length of extent */
-       int             *stat)          /* success/failure */
-{
-       cur->bc_rec.a.ar_startblock = bno;
-       cur->bc_rec.a.ar_blockcount = len;
-       return xfs_alloc_lookup(cur, XFS_LOOKUP_GE, stat);
-}
-
-/*
- * Lookup the first record less than or equal to [bno, len]
- * in the btree given by cur.
- */
-int                                    /* error */
-xfs_alloc_lookup_le(
-       xfs_btree_cur_t *cur,           /* btree cursor */
-       xfs_agblock_t   bno,            /* starting block of extent */
-       xfs_extlen_t    len,            /* length of extent */
-       int             *stat)          /* success/failure */
-{
-       cur->bc_rec.a.ar_startblock = bno;
-       cur->bc_rec.a.ar_blockcount = len;
-       return xfs_alloc_lookup(cur, XFS_LOOKUP_LE, stat);
-}
-
 /*
  * Update the record referred to by cur, to the value given by [bno, len].
  * This either works (return 0) or gets an EFSCORRUPTED error.
@@ -2052,6 +1788,51 @@ xfs_allocbt_get_maxrecs(
        return cur->bc_mp->m_alloc_mxr[level != 0];
 }
 
+STATIC void
+xfs_allocbt_init_key_from_rec(
+       union xfs_btree_key     *key,
+       union xfs_btree_rec     *rec)
+{
+       ASSERT(rec->alloc.ar_startblock != 0);
+
+       key->alloc.ar_startblock = rec->alloc.ar_startblock;
+       key->alloc.ar_blockcount = rec->alloc.ar_blockcount;
+}
+
+STATIC void
+xfs_allocbt_init_ptr_from_cur(
+       struct xfs_btree_cur    *cur,
+       union xfs_btree_ptr     *ptr)
+{
+       struct xfs_agf          *agf = XFS_BUF_TO_AGF(cur->bc_private.a.agbp);
+
+       ASSERT(cur->bc_private.a.agno == be32_to_cpu(agf->agf_seqno));
+       ASSERT(agf->agf_roots[cur->bc_btnum] != 0);
+
+       ptr->s = agf->agf_roots[cur->bc_btnum];
+}
+
+STATIC __int64_t
+xfs_allocbt_key_diff(
+       struct xfs_btree_cur    *cur,
+       union xfs_btree_key     *key)
+{
+       xfs_alloc_rec_incore_t  *rec = &cur->bc_rec.a;
+       xfs_alloc_key_t         *kp = &key->alloc;
+       __int64_t               diff;
+
+       if (cur->bc_btnum == XFS_BTNUM_BNO) {
+               return (__int64_t)be32_to_cpu(kp->ar_startblock) -
+                               rec->ar_startblock;
+       }
+
+       diff = (__int64_t)be32_to_cpu(kp->ar_blockcount) - rec->ar_blockcount;
+       if (diff)
+               return diff;
+
+       return (__int64_t)be32_to_cpu(kp->ar_startblock) - rec->ar_startblock;
+}
+
 #ifdef XFS_BTREE_TRACE
 ktrace_t       *xfs_allocbt_trace_buf;
 
@@ -2124,6 +1905,9 @@ static const struct xfs_btree_ops xfs_allocbt_ops = {
 
        .dup_cursor             = xfs_allocbt_dup_cursor,
        .get_maxrecs            = xfs_allocbt_get_maxrecs,
+       .init_key_from_rec      = xfs_allocbt_init_key_from_rec,
+       .init_ptr_from_cur      = xfs_allocbt_init_ptr_from_cur,
+       .key_diff               = xfs_allocbt_key_diff,
 
 #ifdef XFS_BTREE_TRACE
        .trace_enter            = xfs_allocbt_trace_enter,