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[XFS] implement generic xfs_btree_split

Browse source 
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
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200
fs/xfs/xfs_alloc_btree.c
View file

@ -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,

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,

268
fs/xfs/xfs_btree.c
View file

@ -988,6 +988,48 @@ xfs_btree_get_sibling(
}
}
STATIC void
xfs_btree_set_sibling(
struct xfs_btree_cur *cur,
struct xfs_btree_block *block,
union xfs_btree_ptr *ptr,
int lr)
{
ASSERT(lr == XFS_BB_LEFTSIB || lr == XFS_BB_RIGHTSIB);
if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
if (lr == XFS_BB_RIGHTSIB)
block->bb_u.l.bb_rightsib = ptr->l;
else
block->bb_u.l.bb_leftsib = ptr->l;
} else {
if (lr == XFS_BB_RIGHTSIB)
block->bb_u.s.bb_rightsib = ptr->s;
else
block->bb_u.s.bb_leftsib = ptr->s;
}
}
STATIC void
xfs_btree_init_block(
struct xfs_btree_cur *cur,
int level,
int numrecs,
struct xfs_btree_block *new) /* new block */
{
new->bb_magic = cpu_to_be32(xfs_magics[cur->bc_btnum]);
new->bb_level = cpu_to_be16(level);
new->bb_numrecs = cpu_to_be16(numrecs);
if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
new->bb_u.l.bb_leftsib = cpu_to_be64(NULLFSBLOCK);
new->bb_u.l.bb_rightsib = cpu_to_be64(NULLFSBLOCK);
} else {
new->bb_u.s.bb_leftsib = cpu_to_be32(NULLAGBLOCK);
new->bb_u.s.bb_rightsib = cpu_to_be32(NULLAGBLOCK);
}
}
/*
* Return true if ptr is the last record in the btree and
* we need to track updateѕ to this record. The decision
@ -1012,6 +1054,21 @@ xfs_btree_is_lastrec(
return 1;
}
STATIC void
xfs_btree_buf_to_ptr(
struct xfs_btree_cur *cur,
struct xfs_buf *bp,
union xfs_btree_ptr *ptr)
{
if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
ptr->l = cpu_to_be64(XFS_DADDR_TO_FSB(cur->bc_mp,
XFS_BUF_ADDR(bp)));
else {
ptr->s = cpu_to_be32(XFS_DADDR_TO_AGBNO(cur->bc_mp,
XFS_BUF_ADDR(bp)));
}
}
STATIC xfs_daddr_t
xfs_btree_ptr_to_daddr(
struct xfs_btree_cur *cur,
@ -1051,6 +1108,31 @@ xfs_btree_set_refs(
}
}
STATIC int
xfs_btree_get_buf_block(
struct xfs_btree_cur *cur,
union xfs_btree_ptr *ptr,
int flags,
struct xfs_btree_block **block,
struct xfs_buf **bpp)
{
struct xfs_mount *mp = cur->bc_mp;
xfs_daddr_t d;
/* need to sort out how callers deal with failures first */
ASSERT(!(flags & XFS_BUF_TRYLOCK));
d = xfs_btree_ptr_to_daddr(cur, ptr);
*bpp = xfs_trans_get_buf(cur->bc_tp, mp->m_ddev_targp, d,
mp->m_bsize, flags);
ASSERT(*bpp);
ASSERT(!XFS_BUF_GETERROR(*bpp));
*block = XFS_BUF_TO_BLOCK(*bpp);
return 0;
}
/*
* Read in the buffer at the given ptr and return the buffer and
* the block pointer within the buffer.
@ -2199,3 +2281,189 @@ xfs_btree_rshift(
xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
return error;
}
/*
* Split cur/level block in half.
* Return new block number and the key to its first
* record (to be inserted into parent).
*/
int /* error */
xfs_btree_split(
struct xfs_btree_cur *cur,
int level,
union xfs_btree_ptr *ptrp,
union xfs_btree_key *key,
struct xfs_btree_cur **curp,
int *stat) /* success/failure */
{
union xfs_btree_ptr lptr; /* left sibling block ptr */
struct xfs_buf *lbp; /* left buffer pointer */
struct xfs_btree_block *left; /* left btree block */
union xfs_btree_ptr rptr; /* right sibling block ptr */
struct xfs_buf *rbp; /* right buffer pointer */
struct xfs_btree_block *right; /* right btree block */
union xfs_btree_ptr rrptr; /* right-right sibling ptr */
struct xfs_buf *rrbp; /* right-right buffer pointer */
struct xfs_btree_block *rrblock; /* right-right btree block */
int lrecs;
int rrecs;
int src_index;
int error; /* error return value */
#ifdef DEBUG
int i;
#endif
XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
XFS_BTREE_TRACE_ARGIPK(cur, level, *ptrp, key);
XFS_BTREE_STATS_INC(cur, split);
/* Set up left block (current one). */
left = xfs_btree_get_block(cur, level, &lbp);
#ifdef DEBUG
error = xfs_btree_check_block(cur, left, level, lbp);
if (error)
goto error0;
#endif
xfs_btree_buf_to_ptr(cur, lbp, &lptr);
/* Allocate the new block. If we can't do it, we're toast. Give up. */
error = cur->bc_ops->alloc_block(cur, &lptr, &rptr, 1, stat);
if (error)
goto error0;
if (*stat == 0)
goto out0;
XFS_BTREE_STATS_INC(cur, alloc);
/* Set up the new block as "right". */
error = xfs_btree_get_buf_block(cur, &rptr, 0, &right, &rbp);
if (error)
goto error0;
/* Fill in the btree header for the new right block. */
xfs_btree_init_block(cur, xfs_btree_get_level(left), 0, right);
/*
* Split the entries between the old and the new block evenly.
* Make sure that if there's an odd number of entries now, that
* each new block will have the same number of entries.
*/
lrecs = xfs_btree_get_numrecs(left);
rrecs = lrecs / 2;
if ((lrecs & 1) && cur->bc_ptrs[level] <= rrecs + 1)
rrecs++;
src_index = (lrecs - rrecs + 1);
XFS_BTREE_STATS_ADD(cur, moves, rrecs);
/*
* Copy btree block entries from the left block over to the
* new block, the right. Update the right block and log the
* changes.
*/
if (level > 0) {
/* It's a non-leaf. Move keys and pointers. */
union xfs_btree_key *lkp; /* left btree key */
union xfs_btree_ptr *lpp; /* left address pointer */
union xfs_btree_key *rkp; /* right btree key */
union xfs_btree_ptr *rpp; /* right address pointer */
lkp = xfs_btree_key_addr(cur, src_index, left);
lpp = xfs_btree_ptr_addr(cur, src_index, left);
rkp = xfs_btree_key_addr(cur, 1, right);
rpp = xfs_btree_ptr_addr(cur, 1, right);
#ifdef DEBUG
for (i = src_index; i < rrecs; i++) {
error = xfs_btree_check_ptr(cur, lpp, i, level);
if (error)
goto error0;
}
#endif
xfs_btree_copy_keys(cur, rkp, lkp, rrecs);
xfs_btree_copy_ptrs(cur, rpp, lpp, rrecs);
xfs_btree_log_keys(cur, rbp, 1, rrecs);
xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
/* Grab the keys to the entries moved to the right block */
xfs_btree_copy_keys(cur, key, rkp, 1);
} else {
/* It's a leaf. Move records. */
union xfs_btree_rec *lrp; /* left record pointer */
union xfs_btree_rec *rrp; /* right record pointer */
lrp = xfs_btree_rec_addr(cur, src_index, left);
rrp = xfs_btree_rec_addr(cur, 1, right);
xfs_btree_copy_recs(cur, rrp, lrp, rrecs);
xfs_btree_log_recs(cur, rbp, 1, rrecs);
cur->bc_ops->init_key_from_rec(key,
xfs_btree_rec_addr(cur, 1, right));
}
/*
* Find the left block number by looking in the buffer.
* Adjust numrecs, sibling pointers.
*/
xfs_btree_get_sibling(cur, left, &rrptr, XFS_BB_RIGHTSIB);
xfs_btree_set_sibling(cur, right, &rrptr, XFS_BB_RIGHTSIB);
xfs_btree_set_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
xfs_btree_set_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
lrecs -= rrecs;
xfs_btree_set_numrecs(left, lrecs);
xfs_btree_set_numrecs(right, xfs_btree_get_numrecs(right) + rrecs);
xfs_btree_log_block(cur, rbp, XFS_BB_ALL_BITS);
xfs_btree_log_block(cur, 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 (!xfs_btree_ptr_is_null(cur, &rrptr)) {
error = xfs_btree_read_buf_block(cur, &rrptr, level,
0, &rrblock, &rrbp);
if (error)
goto error0;
xfs_btree_set_sibling(cur, rrblock, &rptr, XFS_BB_LEFTSIB);
xfs_btree_log_block(cur, 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] > lrecs + 1) {
xfs_btree_setbuf(cur, level, rbp);
cur->bc_ptrs[level] -= lrecs;
}
/*
* If there are more levels, we'll need another cursor which refers
* the right block, no matter where this cursor was.
*/
if (level + 1 < cur->bc_nlevels) {
error = xfs_btree_dup_cursor(cur, curp);
if (error)
goto error0;
(*curp)->bc_ptrs[level + 1]++;
}
*ptrp = rptr;
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
*stat = 1;
return 0;
out0:
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
*stat = 0;
return 0;
error0:
XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
return error;
}

8
fs/xfs/xfs_btree.h
View file

@ -187,6 +187,12 @@ struct xfs_btree_ops {
/* cursor operations */
struct xfs_btree_cur *(*dup_cursor)(struct xfs_btree_cur *);
/* block allocation / freeing */
int (*alloc_block)(struct xfs_btree_cur *cur,
union xfs_btree_ptr *start_bno,
union xfs_btree_ptr *new_bno,
int length, int *stat);
/* update last record information */
void (*update_lastrec)(struct xfs_btree_cur *cur,
struct xfs_btree_block *block,
@ -535,6 +541,8 @@ int xfs_btree_updkey(struct xfs_btree_cur *, union xfs_btree_key *, int);
int xfs_btree_update(struct xfs_btree_cur *, union xfs_btree_rec *);
int xfs_btree_lshift(struct xfs_btree_cur *, int, int *);
int xfs_btree_rshift(struct xfs_btree_cur *, int, int *);
int xfs_btree_split(struct xfs_btree_cur *, int, union xfs_btree_ptr *,
union xfs_btree_key *, struct xfs_btree_cur **, int *);
/*
* Helpers.

212
fs/xfs/xfs_ialloc_btree.c
View file

@ -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"
@ -44,8 +45,6 @@ STATIC void xfs_inobt_log_keys(xfs_btree_cur_t *, xfs_buf_t *, int, int);
STATIC void xfs_inobt_log_ptrs(xfs_btree_cur_t *, xfs_buf_t *, int, int);
STATIC void xfs_inobt_log_recs(xfs_btree_cur_t *, xfs_buf_t *, int, int);
STATIC int xfs_inobt_newroot(xfs_btree_cur_t *, int *);
STATIC int xfs_inobt_split(xfs_btree_cur_t *, int, xfs_agblock_t *,
xfs_inobt_key_t *, xfs_btree_cur_t **, int *);
/*
* Single level of the xfs_inobt_delete record deletion routine.
@ -620,15 +619,18 @@ xfs_inobt_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_inobt_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_INOBT_BLOCK(bp);
@ -972,165 +974,6 @@ xfs_inobt_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_inobt_split(
xfs_btree_cur_t *cur, /* btree cursor */
int level, /* level to split */
xfs_agblock_t *bnop, /* output: block number allocated */
xfs_inobt_key_t *keyp, /* output: first key of new block */
xfs_btree_cur_t **curp, /* output: new cursor */
int *stat) /* success/failure */
{
xfs_alloc_arg_t args; /* allocation argument structure */
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_inobt_block_t *left; /* left (current) btree block */
xfs_inobt_key_t *lkp; /* left btree key pointer */
xfs_inobt_ptr_t *lpp; /* left btree address pointer */
xfs_inobt_rec_t *lrp; /* left btree record pointer */
xfs_buf_t *rbp; /* buffer for right block */
xfs_inobt_block_t *right; /* right (new) btree block */
xfs_inobt_key_t *rkp; /* right btree key pointer */
xfs_inobt_ptr_t *rpp; /* right btree address pointer */
xfs_inobt_rec_t *rrp; /* right btree record pointer */
/*
* Set up left block (current one).
*/
lbp = cur->bc_bufs[level];
args.tp = cur->bc_tp;
args.mp = cur->bc_mp;
lbno = XFS_DADDR_TO_AGBNO(args.mp, XFS_BUF_ADDR(lbp));
/*
* Allocate the new block.
* If we can't do it, we're toast. Give up.
*/
args.fsbno = XFS_AGB_TO_FSB(args.mp, cur->bc_private.a.agno, lbno);
args.mod = args.minleft = args.alignment = args.total = args.wasdel =
args.isfl = args.userdata = args.minalignslop = 0;
args.minlen = args.maxlen = args.prod = 1;
args.type = XFS_ALLOCTYPE_NEAR_BNO;
if ((error = xfs_alloc_vextent(&args)))
return error;
if (args.fsbno == NULLFSBLOCK) {
*stat = 0;
return 0;
}
ASSERT(args.len == 1);
rbp = xfs_btree_get_bufs(args.mp, args.tp, args.agno, args.agbno, 0);
/*
* Set up the new block as "right".
*/
right = XFS_BUF_TO_INOBT_BLOCK(rbp);
/*
* "Left" is the current (according to the cursor) block.
*/
left = XFS_BUF_TO_INOBT_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) {
lkp = XFS_INOBT_KEY_ADDR(left, i, cur);
lpp = XFS_INOBT_PTR_ADDR(left, i, cur);
rkp = XFS_INOBT_KEY_ADDR(right, 1, cur);
rpp = XFS_INOBT_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_inobt_log_keys(cur, rbp, 1, be16_to_cpu(right->bb_numrecs));
xfs_inobt_log_ptrs(cur, rbp, 1, be16_to_cpu(right->bb_numrecs));
*keyp = *rkp;
}
/*
* For leaf blocks, copy records over to the new block.
*/
else {
lrp = XFS_INOBT_REC_ADDR(left, i, cur);
rrp = XFS_INOBT_REC_ADDR(right, 1, cur);
memcpy(rrp, lrp, be16_to_cpu(right->bb_numrecs) * sizeof(*rrp));
xfs_inobt_log_recs(cur, rbp, 1, be16_to_cpu(right->bb_numrecs));
keyp->ir_startino = rrp->ir_startino;
}
/*
* Find the left block number by looking in the buffer.
* Adjust numrecs, sibling pointers.
*/
be16_add_cpu(&left->bb_numrecs, -(be16_to_cpu(right->bb_numrecs)));
right->bb_rightsib = left->bb_rightsib;
left->bb_rightsib = cpu_to_be32(args.agbno);
right->bb_leftsib = cpu_to_be32(lbno);
xfs_inobt_log_block(args.tp, rbp, XFS_BB_ALL_BITS);
xfs_inobt_log_block(args.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_inobt_block_t *rrblock; /* rr btree block */
xfs_buf_t *rrbp; /* buffer for rrblock */
if ((error = xfs_btree_read_bufs(args.mp, args.tp, args.agno,
be32_to_cpu(right->bb_rightsib), 0, &rrbp,
XFS_INO_BTREE_REF)))
return error;
rrblock = XFS_BUF_TO_INOBT_BLOCK(rrbp);
if ((error = xfs_btree_check_sblock(cur, rrblock, level, rrbp)))
return error;
rrblock->bb_leftsib = cpu_to_be32(args.agbno);
xfs_inobt_log_block(args.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
* 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 = args.agbno;
*stat = 1;
return 0;
}
/*
* Externally visible routines.
*/
@ -1285,6 +1128,48 @@ xfs_inobt_dup_cursor(
cur->bc_private.a.agbp, cur->bc_private.a.agno);
}
STATIC int
xfs_inobt_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 */
xfs_agblock_t sbno = be32_to_cpu(start->s);
XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
memset(&args, 0, sizeof(args));
args.tp = cur->bc_tp;
args.mp = cur->bc_mp;
args.fsbno = XFS_AGB_TO_FSB(args.mp, cur->bc_private.a.agno, sbno);
args.minlen = 1;
args.maxlen = 1;
args.prod = 1;
args.type = XFS_ALLOCTYPE_NEAR_BNO;
error = xfs_alloc_vextent(&args);
if (error) {
XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
return error;
}
if (args.fsbno == NULLFSBLOCK) {
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
*stat = 0;
return 0;
}
ASSERT(args.len == 1);
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
new->s = cpu_to_be32(XFS_FSB_TO_AGBNO(args.mp, args.fsbno));
*stat = 1;
return 0;
}
STATIC int
xfs_inobt_get_maxrecs(
struct xfs_btree_cur *cur,
@ -1396,6 +1281,7 @@ static const struct xfs_btree_ops xfs_inobt_ops = {
.key_len = sizeof(xfs_inobt_key_t),
.dup_cursor = xfs_inobt_dup_cursor,
.alloc_block = xfs_inobt_alloc_block,
.get_maxrecs = xfs_inobt_get_maxrecs,
.init_key_from_rec = xfs_inobt_init_key_from_rec,
.init_ptr_from_cur = xfs_inobt_init_ptr_from_cur,