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[XFS] implement generic xfs_btree_split

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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 <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>
This commit is contained in:
Christoph Hellwig
2008-10-30 16:57:03 +11:00
committed by Lachlan McIlroy
parent 687b890a18
commit f5eb8e7ca5
5 changed files with 460 additions and 503 deletions
Download Patch File Download Diff File Expand all files Collapse all files

275
fs/xfs/xfs_bmap_btree.c
View File

@@ -52,8 +52,6 @@
STATIC int xfs_bmbt_killroot(xfs_btree_cur_t *);
STATIC void xfs_bmbt_log_keys(xfs_btree_cur_t *, xfs_buf_t *, int, int);
STATIC void xfs_bmbt_log_ptrs(xfs_btree_cur_t *, xfs_buf_t *, int, int);
STATIC int xfs_bmbt_split(xfs_btree_cur_t *, int, xfs_fsblock_t *,
__uint64_t *, xfs_btree_cur_t **, int *);
#undef EXIT
@@ -550,13 +548,17 @@ xfs_bmbt_insrec(
if (i) {
optr = ptr = cur->bc_ptrs[level];
} else {
if ((error = xfs_bmbt_split(cur, level,
&nbno, &startoff, &ncur,
union xfs_btree_ptr bno = { .l = cpu_to_be64(nbno) };
union xfs_btree_key skey;
if ((error = xfs_btree_split(cur, level,
&bno, &skey, &ncur,
&i))) {
XFS_BMBT_TRACE_CURSOR(cur,
ERROR);
return error;
}
nbno = be64_to_cpu(bno.l);
startoff = be64_to_cpu(skey.bmbt.br_startoff);
if (i) {
block = xfs_bmbt_get_block(
cur, level, &bp);
@@ -825,184 +827,6 @@ xfs_extent_state(
return XFS_EXT_NORM;
}
/*
* Split cur/level block in half.
* Return new block number and its first record (to be inserted into parent).
*/
STATIC int /* error */
xfs_bmbt_split(
xfs_btree_cur_t *cur,
int level,
xfs_fsblock_t *bnop,
__uint64_t *startoff,
xfs_btree_cur_t **curp,
int *stat) /* success/failure */
{
xfs_alloc_arg_t args; /* block allocation args */
int error; /* error return value */
int i; /* loop counter */
xfs_fsblock_t lbno; /* left sibling block number */
xfs_buf_t *lbp; /* left buffer pointer */
xfs_bmbt_block_t *left; /* left btree block */
xfs_bmbt_key_t *lkp; /* left btree key */
xfs_bmbt_ptr_t *lpp; /* left address pointer */
xfs_bmbt_rec_t *lrp; /* left record pointer */
xfs_buf_t *rbp; /* right buffer pointer */
xfs_bmbt_block_t *right; /* right btree block */
xfs_bmbt_key_t *rkp; /* right btree key */
xfs_bmbt_ptr_t *rpp; /* right address pointer */
xfs_bmbt_block_t *rrblock; /* right-right btree block */
xfs_buf_t *rrbp; /* right-right buffer pointer */
xfs_bmbt_rec_t *rrp; /* right record pointer */
XFS_BMBT_TRACE_CURSOR(cur, ENTRY);
// disable until merged into common code
// XFS_BMBT_TRACE_ARGIFK(cur, level, *bnop, *startoff);
args.tp = cur->bc_tp;
args.mp = cur->bc_mp;
lbp = cur->bc_bufs[level];
lbno = XFS_DADDR_TO_FSB(args.mp, XFS_BUF_ADDR(lbp));
left = XFS_BUF_TO_BMBT_BLOCK(lbp);
args.fsbno = cur->bc_private.b.firstblock;
args.firstblock = args.fsbno;
args.minleft = 0;
if (args.fsbno == NULLFSBLOCK) {
args.fsbno = lbno;
args.type = XFS_ALLOCTYPE_START_BNO;
/*
* Make sure there is sufficient room left in the AG to
* complete a full tree split for an extent insert. If
* we are converting the middle part of an extent then
* we may need space for two tree splits.
*
* We are relying on the caller to make the correct block
* reservation for this operation to succeed. If the
* reservation amount is insufficient then we may fail a
* block allocation here and corrupt the filesystem.
*/
args.minleft = xfs_trans_get_block_res(args.tp);
} else if (cur->bc_private.b.flist->xbf_low)
args.type = XFS_ALLOCTYPE_START_BNO;
else
args.type = XFS_ALLOCTYPE_NEAR_BNO;
args.mod = args.alignment = args.total = args.isfl =
args.userdata = args.minalignslop = 0;
args.minlen = args.maxlen = args.prod = 1;
args.wasdel = cur->bc_private.b.flags & XFS_BTCUR_BPRV_WASDEL;
if (!args.wasdel && xfs_trans_get_block_res(args.tp) == 0) {
XFS_BMBT_TRACE_CURSOR(cur, ERROR);
return XFS_ERROR(ENOSPC);
}
if ((error = xfs_alloc_vextent(&args))) {
XFS_BMBT_TRACE_CURSOR(cur, ERROR);
return error;
}
if (args.fsbno == NULLFSBLOCK && args.minleft) {
/*
* Could not find an AG with enough free space to satisfy
* a full btree split. Try again without minleft and if
* successful activate the lowspace algorithm.
*/
args.fsbno = 0;
args.type = XFS_ALLOCTYPE_FIRST_AG;
args.minleft = 0;
if ((error = xfs_alloc_vextent(&args))) {
XFS_BMBT_TRACE_CURSOR(cur, ERROR);
return error;
}
cur->bc_private.b.flist->xbf_low = 1;
}
if (args.fsbno == NULLFSBLOCK) {
XFS_BMBT_TRACE_CURSOR(cur, EXIT);
*stat = 0;
return 0;
}
ASSERT(args.len == 1);
cur->bc_private.b.firstblock = args.fsbno;
cur->bc_private.b.allocated++;
cur->bc_private.b.ip->i_d.di_nblocks++;
xfs_trans_log_inode(args.tp, cur->bc_private.b.ip, XFS_ILOG_CORE);
XFS_TRANS_MOD_DQUOT_BYINO(args.mp, args.tp, cur->bc_private.b.ip,
XFS_TRANS_DQ_BCOUNT, 1L);
rbp = xfs_btree_get_bufl(args.mp, args.tp, args.fsbno, 0);
right = XFS_BUF_TO_BMBT_BLOCK(rbp);
#ifdef DEBUG
if ((error = xfs_btree_check_lblock(cur, left, level, rbp))) {
XFS_BMBT_TRACE_CURSOR(cur, ERROR);
return error;
}
#endif
right->bb_magic = cpu_to_be32(XFS_BMAP_MAGIC);
right->bb_level = left->bb_level;
right->bb_numrecs = cpu_to_be16(be16_to_cpu(left->bb_numrecs) / 2);
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;
if (level > 0) {
lkp = XFS_BMAP_KEY_IADDR(left, i, cur);
lpp = XFS_BMAP_PTR_IADDR(left, i, cur);
rkp = XFS_BMAP_KEY_IADDR(right, 1, cur);
rpp = XFS_BMAP_PTR_IADDR(right, 1, cur);
#ifdef DEBUG
for (i = 0; i < be16_to_cpu(right->bb_numrecs); i++) {
if ((error = xfs_btree_check_lptr_disk(cur, lpp[i], level))) {
XFS_BMBT_TRACE_CURSOR(cur, ERROR);
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_bmbt_log_keys(cur, rbp, 1, be16_to_cpu(right->bb_numrecs));
xfs_bmbt_log_ptrs(cur, rbp, 1, be16_to_cpu(right->bb_numrecs));
*startoff = be64_to_cpu(rkp->br_startoff);
} else {
lrp = XFS_BMAP_REC_IADDR(left, i, cur);
rrp = XFS_BMAP_REC_IADDR(right, 1, cur);
memcpy(rrp, lrp, be16_to_cpu(right->bb_numrecs) * sizeof(*rrp));
xfs_bmbt_log_recs(cur, rbp, 1, be16_to_cpu(right->bb_numrecs));
*startoff = xfs_bmbt_disk_get_startoff(rrp);
}
be16_add_cpu(&left->bb_numrecs, -(be16_to_cpu(right->bb_numrecs)));
right->bb_rightsib = left->bb_rightsib;
left->bb_rightsib = cpu_to_be64(args.fsbno);
right->bb_leftsib = cpu_to_be64(lbno);
xfs_bmbt_log_block(cur, rbp, XFS_BB_ALL_BITS);
xfs_bmbt_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
if (be64_to_cpu(right->bb_rightsib) != NULLDFSBNO) {
if ((error = xfs_btree_read_bufl(args.mp, args.tp,
be64_to_cpu(right->bb_rightsib), 0, &rrbp,
XFS_BMAP_BTREE_REF))) {
XFS_BMBT_TRACE_CURSOR(cur, ERROR);
return error;
}
rrblock = XFS_BUF_TO_BMBT_BLOCK(rrbp);
if ((error = xfs_btree_check_lblock(cur, rrblock, level, rrbp))) {
XFS_BMBT_TRACE_CURSOR(cur, ERROR);
return error;
}
rrblock->bb_leftsib = cpu_to_be64(args.fsbno);
xfs_bmbt_log_block(cur, rrbp, XFS_BB_LEFTSIB);
}
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 (level + 1 < cur->bc_nlevels) {
if ((error = xfs_btree_dup_cursor(cur, curp))) {
XFS_BMBT_TRACE_CURSOR(cur, ERROR);
return error;
}
(*curp)->bc_ptrs[level + 1]++;
}
*bnop = args.fsbno;
XFS_BMBT_TRACE_CURSOR(cur, EXIT);
*stat = 1;
return 0;
}
/*
* Convert on-disk form of btree root to in-memory form.
*/
@@ -1737,6 +1561,92 @@ xfs_bmbt_dup_cursor(
return new;
}
STATIC int
xfs_bmbt_alloc_block(
struct xfs_btree_cur *cur,
union xfs_btree_ptr *start,
union xfs_btree_ptr *new,
int length,
int *stat)
{
xfs_alloc_arg_t args; /* block allocation args */
int error; /* error return value */
memset(&args, 0, sizeof(args));
args.tp = cur->bc_tp;
args.mp = cur->bc_mp;
args.fsbno = cur->bc_private.b.firstblock;
args.firstblock = args.fsbno;
if (args.fsbno == NULLFSBLOCK) {
args.fsbno = be64_to_cpu(start->l);
args.type = XFS_ALLOCTYPE_START_BNO;
/*
* Make sure there is sufficient room left in the AG to
* complete a full tree split for an extent insert. If
* we are converting the middle part of an extent then
* we may need space for two tree splits.
*
* We are relying on the caller to make the correct block
* reservation for this operation to succeed. If the
* reservation amount is insufficient then we may fail a
* block allocation here and corrupt the filesystem.
*/
args.minleft = xfs_trans_get_block_res(args.tp);
} else if (cur->bc_private.b.flist->xbf_low) {
args.type = XFS_ALLOCTYPE_START_BNO;
} else {
args.type = XFS_ALLOCTYPE_NEAR_BNO;
}
args.minlen = args.maxlen = args.prod = 1;
args.wasdel = cur->bc_private.b.flags & XFS_BTCUR_BPRV_WASDEL;
if (!args.wasdel && xfs_trans_get_block_res(args.tp) == 0) {
error = XFS_ERROR(ENOSPC);
goto error0;
}
error = xfs_alloc_vextent(&args);
if (error)
goto error0;
if (args.fsbno == NULLFSBLOCK && args.minleft) {
/*
* Could not find an AG with enough free space to satisfy
* a full btree split. Try again without minleft and if
* successful activate the lowspace algorithm.
*/
args.fsbno = 0;
args.type = XFS_ALLOCTYPE_FIRST_AG;
args.minleft = 0;
error = xfs_alloc_vextent(&args);
if (error)
goto error0;
cur->bc_private.b.flist->xbf_low = 1;
}
if (args.fsbno == NULLFSBLOCK) {
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
*stat = 0;
return 0;
}
ASSERT(args.len == 1);
cur->bc_private.b.firstblock = args.fsbno;
cur->bc_private.b.allocated++;
cur->bc_private.b.ip->i_d.di_nblocks++;
xfs_trans_log_inode(args.tp, cur->bc_private.b.ip, XFS_ILOG_CORE);
XFS_TRANS_MOD_DQUOT_BYINO(args.mp, args.tp, cur->bc_private.b.ip,
XFS_TRANS_DQ_BCOUNT, 1L);
new->l = cpu_to_be64(args.fsbno);
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
*stat = 1;
return 0;
error0:
XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
return error;
}
STATIC int
xfs_bmbt_get_maxrecs(
struct xfs_btree_cur *cur,
@@ -1861,6 +1771,7 @@ static const struct xfs_btree_ops xfs_bmbt_ops = {
.key_len = sizeof(xfs_bmbt_key_t),
.dup_cursor = xfs_bmbt_dup_cursor,
.alloc_block = xfs_bmbt_alloc_block,
.get_maxrecs = xfs_bmbt_get_maxrecs,
.init_key_from_rec = xfs_bmbt_init_key_from_rec,
.init_ptr_from_cur = xfs_bmbt_init_ptr_from_cur,