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author | Christoph Hellwig <hch@infradead.org> | 2008-10-30 16:57:40 +1100 |
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committer | Lachlan McIlroy <lachlan@sgi.com> | 2008-10-30 16:57:40 +1100 |
commit | 4b22a57188d87e873346b73c227607715be96399 (patch) | |
tree | 4cf2d0deede695968b7a32b098c0c64fac8610e5 /fs/xfs/xfs_alloc_btree.c | |
parent | ea77b0a66e6c910ef265d9af522d6303ea6b3055 (diff) | |
download | linux-stable-4b22a57188d87e873346b73c227607715be96399.tar.gz linux-stable-4b22a57188d87e873346b73c227607715be96399.tar.bz2 linux-stable-4b22a57188d87e873346b73c227607715be96399.zip |
[XFS] implement generic xfs_btree_insert/insrec
Make the btree insert 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:32202a
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Bill O'Donnell <billodo@sgi.com>
Signed-off-by: David Chinner <david@fromorbit.com>
Diffstat (limited to 'fs/xfs/xfs_alloc_btree.c')
-rw-r--r-- | fs/xfs/xfs_alloc_btree.c | 339 |
1 files changed, 30 insertions, 309 deletions
diff --git a/fs/xfs/xfs_alloc_btree.c b/fs/xfs/xfs_alloc_btree.c index f21a3e9cc3db..818adca77fc6 100644 --- a/fs/xfs/xfs_alloc_btree.c +++ b/fs/xfs/xfs_alloc_btree.c @@ -583,256 +583,6 @@ error0: } /* - * Insert one record/level. Return information to the caller - * allowing the next level up to proceed if necessary. - */ -STATIC int /* error */ -xfs_alloc_insrec( - xfs_btree_cur_t *cur, /* btree cursor */ - int level, /* level to insert record at */ - xfs_agblock_t *bnop, /* i/o: block number inserted */ - xfs_alloc_rec_t *recp, /* i/o: record data inserted */ - xfs_btree_cur_t **curp, /* output: new cursor replacing cur */ - int *stat) /* output: success/failure */ -{ - xfs_agf_t *agf; /* allocation group freelist header */ - xfs_alloc_block_t *block; /* btree block record/key lives in */ - xfs_buf_t *bp; /* buffer for block */ - int error; /* error return value */ - int i; /* loop index */ - xfs_alloc_key_t key; /* key value being inserted */ - xfs_alloc_key_t *kp; /* pointer to btree keys */ - xfs_agblock_t nbno; /* block number of allocated block */ - xfs_btree_cur_t *ncur; /* new cursor to be used at next lvl */ - xfs_alloc_key_t nkey; /* new key value, from split */ - xfs_alloc_rec_t nrec; /* new record value, for caller */ - int numrecs; - int optr; /* old ptr value */ - xfs_alloc_ptr_t *pp; /* pointer to btree addresses */ - int ptr; /* index in btree block for this rec */ - xfs_alloc_rec_t *rp; /* pointer to btree records */ - - ASSERT(be32_to_cpu(recp->ar_blockcount) > 0); - - /* - * GCC doesn't understand the (arguably complex) control flow in - * this function and complains about uninitialized structure fields - * without this. - */ - memset(&nrec, 0, sizeof(nrec)); - - /* - * If we made it to the root level, allocate a new root block - * and we're done. - */ - if (level >= cur->bc_nlevels) { - XFS_STATS_INC(xs_abt_insrec); - if ((error = xfs_btree_new_root(cur, &i))) - return error; - *bnop = NULLAGBLOCK; - *stat = i; - return 0; - } - /* - * Make a key out of the record data to be inserted, and save it. - */ - key.ar_startblock = recp->ar_startblock; - key.ar_blockcount = recp->ar_blockcount; - optr = ptr = cur->bc_ptrs[level]; - /* - * If we're off the left edge, return failure. - */ - if (ptr == 0) { - *stat = 0; - return 0; - } - XFS_STATS_INC(xs_abt_insrec); - /* - * Get pointers to the btree buffer and block. - */ - bp = cur->bc_bufs[level]; - block = XFS_BUF_TO_ALLOC_BLOCK(bp); - numrecs = be16_to_cpu(block->bb_numrecs); -#ifdef DEBUG - if ((error = xfs_btree_check_sblock(cur, block, level, bp))) - return error; - /* - * Check that the new entry is being inserted in the right place. - */ - if (ptr <= numrecs) { - if (level == 0) { - rp = XFS_ALLOC_REC_ADDR(block, ptr, cur); - xfs_btree_check_rec(cur->bc_btnum, recp, rp); - } else { - kp = XFS_ALLOC_KEY_ADDR(block, ptr, cur); - xfs_btree_check_key(cur->bc_btnum, &key, kp); - } - } -#endif - nbno = NULLAGBLOCK; - ncur = NULL; - /* - * If the block is full, we can't insert the new entry until we - * make the block un-full. - */ - if (numrecs == XFS_ALLOC_BLOCK_MAXRECS(level, cur)) { - /* - * First, try shifting an entry to the right neighbor. - */ - if ((error = xfs_btree_rshift(cur, level, &i))) - return error; - if (i) { - /* nothing */ - } - /* - * Next, try shifting an entry to the left neighbor. - */ - else { - if ((error = xfs_btree_lshift(cur, level, &i))) - return error; - 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_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); -#ifdef DEBUG - if ((error = - xfs_btree_check_sblock(cur, - block, level, bp))) - return error; -#endif - ptr = cur->bc_ptrs[level]; - nrec.ar_startblock = nkey.ar_startblock; - nrec.ar_blockcount = nkey.ar_blockcount; - } - /* - * Otherwise the insert fails. - */ - else { - *stat = 0; - return 0; - } - } - } - } - /* - * At this point we know there's room for our new entry in the block - * we're pointing at. - */ - numrecs = be16_to_cpu(block->bb_numrecs); - if (level > 0) { - /* - * It's a non-leaf entry. Make a hole for the new data - * in the key and ptr regions of the block. - */ - kp = XFS_ALLOC_KEY_ADDR(block, 1, cur); - pp = XFS_ALLOC_PTR_ADDR(block, 1, cur); -#ifdef DEBUG - for (i = numrecs; i >= ptr; i--) { - if ((error = xfs_btree_check_sptr(cur, be32_to_cpu(pp[i - 1]), level))) - return error; - } -#endif - memmove(&kp[ptr], &kp[ptr - 1], - (numrecs - ptr + 1) * sizeof(*kp)); - memmove(&pp[ptr], &pp[ptr - 1], - (numrecs - ptr + 1) * sizeof(*pp)); -#ifdef DEBUG - if ((error = xfs_btree_check_sptr(cur, *bnop, level))) - return error; -#endif - /* - * Now stuff the new data in, bump numrecs and log the new data. - */ - kp[ptr - 1] = key; - pp[ptr - 1] = cpu_to_be32(*bnop); - numrecs++; - block->bb_numrecs = cpu_to_be16(numrecs); - xfs_alloc_log_keys(cur, bp, ptr, numrecs); - xfs_alloc_log_ptrs(cur, bp, ptr, numrecs); -#ifdef DEBUG - if (ptr < numrecs) - xfs_btree_check_key(cur->bc_btnum, kp + ptr - 1, - kp + ptr); -#endif - } else { - /* - * It's a leaf entry. Make a hole for the new record. - */ - rp = XFS_ALLOC_REC_ADDR(block, 1, cur); - memmove(&rp[ptr], &rp[ptr - 1], - (numrecs - ptr + 1) * sizeof(*rp)); - /* - * Now stuff the new record in, bump numrecs - * and log the new data. - */ - rp[ptr - 1] = *recp; - numrecs++; - block->bb_numrecs = cpu_to_be16(numrecs); - xfs_alloc_log_recs(cur, bp, ptr, numrecs); -#ifdef DEBUG - if (ptr < numrecs) - xfs_btree_check_rec(cur->bc_btnum, rp + ptr - 1, - rp + ptr); -#endif - } - /* - * Log the new number of records in the btree header. - */ - xfs_alloc_log_block(cur->bc_tp, bp, XFS_BB_NUMRECS); - /* - * If we inserted at the start of a block, update the parents' keys. - */ - if (optr == 1 && (error = xfs_btree_updkey(cur, (union xfs_btree_key *)&key, level + 1))) - return error; - /* - * Look to see if the longest extent in the allocation group - * needs to be updated. - */ - - agf = XFS_BUF_TO_AGF(cur->bc_private.a.agbp); - if (level == 0 && - cur->bc_btnum == XFS_BTNUM_CNT && - be32_to_cpu(block->bb_rightsib) == NULLAGBLOCK && - be32_to_cpu(recp->ar_blockcount) > be32_to_cpu(agf->agf_longest)) { - /* - * If this is a leaf in the by-size btree and there - * is no right sibling block and this block is bigger - * than the previous longest block, update it. - */ - agf->agf_longest = recp->ar_blockcount; - cur->bc_mp->m_perag[be32_to_cpu(agf->agf_seqno)].pagf_longest - = be32_to_cpu(recp->ar_blockcount); - xfs_alloc_log_agf(cur->bc_tp, cur->bc_private.a.agbp, - XFS_AGF_LONGEST); - } - /* - * Return the new block number, if any. - * If there is one, give back a record value and a cursor too. - */ - *bnop = nbno; - if (nbno != NULLAGBLOCK) { - *recp = nrec; - *curp = ncur; - } - *stat = 1; - return 0; -} - -/* * Log header fields from a btree block. */ STATIC void @@ -1019,65 +769,6 @@ xfs_alloc_get_rec( return 0; } -/* - * Insert the current record at the point referenced by cur. - * The cursor may be inconsistent on return if splits have been done. - */ -int /* error */ -xfs_alloc_insert( - xfs_btree_cur_t *cur, /* btree cursor */ - int *stat) /* success/failure */ -{ - int error; /* error return value */ - int i; /* result value, 0 for failure */ - int level; /* current level number in btree */ - xfs_agblock_t nbno; /* new block number (split result) */ - xfs_btree_cur_t *ncur; /* new cursor (split result) */ - xfs_alloc_rec_t nrec; /* record being inserted this level */ - xfs_btree_cur_t *pcur; /* previous level's cursor */ - - level = 0; - nbno = NULLAGBLOCK; - nrec.ar_startblock = cpu_to_be32(cur->bc_rec.a.ar_startblock); - nrec.ar_blockcount = cpu_to_be32(cur->bc_rec.a.ar_blockcount); - ncur = NULL; - pcur = cur; - /* - * Loop going up the tree, starting at the leaf level. - * Stop when we don't get a split block, that must mean that - * the insert is finished with this level. - */ - do { - /* - * Insert nrec/nbno into this level of the tree. - * Note if we fail, nbno will be null. - */ - if ((error = xfs_alloc_insrec(pcur, level++, &nbno, &nrec, &ncur, - &i))) { - if (pcur != cur) - xfs_btree_del_cursor(pcur, XFS_BTREE_ERROR); - return error; - } - /* - * See if the cursor we just used is trash. - * Can't trash the caller's cursor, but otherwise we should - * if ncur is a new cursor or we're about to be done. - */ - if (pcur != cur && (ncur || nbno == NULLAGBLOCK)) { - cur->bc_nlevels = pcur->bc_nlevels; - xfs_btree_del_cursor(pcur, XFS_BTREE_NOERROR); - } - /* - * If we got a new cursor, switch to it. - */ - if (ncur) { - pcur = ncur; - ncur = NULL; - } - } while (nbno != NULLAGBLOCK); - *stat = i; - return 0; -} STATIC struct xfs_btree_cur * xfs_allocbt_dup_cursor( @@ -1170,6 +861,12 @@ xfs_allocbt_update_lastrec( return; len = rec->alloc.ar_blockcount; break; + case LASTREC_INSREC: + if (be32_to_cpu(rec->alloc.ar_blockcount) <= + be32_to_cpu(agf->agf_longest)) + return; + len = rec->alloc.ar_blockcount; + break; default: ASSERT(0); return; @@ -1200,6 +897,28 @@ xfs_allocbt_init_key_from_rec( } STATIC void +xfs_allocbt_init_rec_from_key( + union xfs_btree_key *key, + union xfs_btree_rec *rec) +{ + ASSERT(key->alloc.ar_startblock != 0); + + rec->alloc.ar_startblock = key->alloc.ar_startblock; + rec->alloc.ar_blockcount = key->alloc.ar_blockcount; +} + +STATIC void +xfs_allocbt_init_rec_from_cur( + struct xfs_btree_cur *cur, + union xfs_btree_rec *rec) +{ + ASSERT(cur->bc_rec.a.ar_startblock != 0); + + rec->alloc.ar_startblock = cpu_to_be32(cur->bc_rec.a.ar_startblock); + rec->alloc.ar_blockcount = cpu_to_be32(cur->bc_rec.a.ar_blockcount); +} + +STATIC void xfs_allocbt_init_ptr_from_cur( struct xfs_btree_cur *cur, union xfs_btree_ptr *ptr) @@ -1309,6 +1028,8 @@ static const struct xfs_btree_ops xfs_allocbt_ops = { .update_lastrec = xfs_allocbt_update_lastrec, .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, + .init_rec_from_cur = xfs_allocbt_init_rec_from_cur, .init_ptr_from_cur = xfs_allocbt_init_ptr_from_cur, .key_diff = xfs_allocbt_key_diff, |