Skip to content

Commit

Permalink
[XFS] implement semi-generic xfs_btree_new_root
Browse files Browse the repository at this point in the history 
From: Dave Chinner <dgc@sgi.com>

Add a xfs_btree_new_root helper for the alloc and ialloc btrees. The bmap
btree needs it's own version and is not converted.

[hch: split out from bigger patch and minor adaptions]

SGI-PV: 985583

SGI-Modid: xfs-linux-melb:xfs-kern:32200a

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>
  • Loading branch information
Christoph Hellwig authored and Lachlan McIlroy committed Oct 30, 2008
1 parent f5eb8e7 commit 344207c
Show file tree
Hide file tree
Showing 4 changed files with 172 additions and 305 deletions.
179 changes: 22 additions & 157 deletions fs/xfs/xfs_alloc_btree.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -48,7 +48,6 @@ 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);
STATIC int xfs_alloc_newroot(xfs_btree_cur_t *, int *);

/*
* Internal functions.
Expand Down Expand Up @@ -628,7 +627,7 @@ xfs_alloc_insrec(
*/
if (level >= cur->bc_nlevels) {
XFS_STATS_INC(xs_abt_insrec);
if ((error = xfs_alloc_newroot(cur, &i)))
if ((error = xfs_btree_new_root(cur, &i)))
return error;
*bnop = NULLAGBLOCK;
*stat = i;
Expand Down Expand Up @@ -936,161 +935,6 @@ xfs_alloc_log_recs(
xfs_trans_log_buf(cur->bc_tp, bp, first, last);
}

/*
* Allocate a new root block, fill it in.
*/
STATIC int /* error */
xfs_alloc_newroot(
xfs_btree_cur_t *cur, /* btree cursor */
int *stat) /* success/failure */
{
int error; /* error return value */
xfs_agblock_t lbno; /* left block number */
xfs_buf_t *lbp; /* left btree buffer */
xfs_alloc_block_t *left; /* left btree block */
xfs_mount_t *mp; /* mount structure */
xfs_agblock_t nbno; /* new block number */
xfs_buf_t *nbp; /* new (root) buffer */
xfs_alloc_block_t *new; /* new (root) btree block */
int nptr; /* new value for key index, 1 or 2 */
xfs_agblock_t rbno; /* right block number */
xfs_buf_t *rbp; /* right btree buffer */
xfs_alloc_block_t *right; /* right btree block */

mp = cur->bc_mp;

ASSERT(cur->bc_nlevels < XFS_AG_MAXLEVELS(mp));
/*
* Get a buffer from the freelist blocks, for the new root.
*/
error = xfs_alloc_get_freelist(cur->bc_tp,
cur->bc_private.a.agbp, &nbno, 1);
if (error)
return error;
/*
* None available, we fail.
*/
if (nbno == NULLAGBLOCK) {
*stat = 0;
return 0;
}
xfs_trans_agbtree_delta(cur->bc_tp, 1);
nbp = xfs_btree_get_bufs(mp, cur->bc_tp, cur->bc_private.a.agno, nbno,
0);
new = XFS_BUF_TO_ALLOC_BLOCK(nbp);
/*
* Set the root data in the a.g. freespace structure.
*/
{
xfs_agf_t *agf; /* a.g. freespace header */
xfs_agnumber_t seqno;

agf = XFS_BUF_TO_AGF(cur->bc_private.a.agbp);
agf->agf_roots[cur->bc_btnum] = cpu_to_be32(nbno);
be32_add_cpu(&agf->agf_levels[cur->bc_btnum], 1);
seqno = be32_to_cpu(agf->agf_seqno);
mp->m_perag[seqno].pagf_levels[cur->bc_btnum]++;
xfs_alloc_log_agf(cur->bc_tp, cur->bc_private.a.agbp,
XFS_AGF_ROOTS | XFS_AGF_LEVELS);
}
/*
* At the previous root level there are now two blocks: the old
* root, and the new block generated when it was split.
* We don't know which one the cursor is pointing at, so we
* set up variables "left" and "right" for each case.
*/
lbp = cur->bc_bufs[cur->bc_nlevels - 1];
left = XFS_BUF_TO_ALLOC_BLOCK(lbp);
#ifdef DEBUG
if ((error = xfs_btree_check_sblock(cur, left, cur->bc_nlevels - 1, lbp)))
return error;
#endif
if (be32_to_cpu(left->bb_rightsib) != NULLAGBLOCK) {
/*
* Our block is left, pick up the right block.
*/
lbno = XFS_DADDR_TO_AGBNO(mp, XFS_BUF_ADDR(lbp));
rbno = be32_to_cpu(left->bb_rightsib);
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);
if ((error = xfs_btree_check_sblock(cur, right,
cur->bc_nlevels - 1, rbp)))
return error;
nptr = 1;
} else {
/*
* Our block is right, pick up the left block.
*/
rbp = lbp;
right = left;
rbno = XFS_DADDR_TO_AGBNO(mp, XFS_BUF_ADDR(rbp));
lbno = be32_to_cpu(right->bb_leftsib);
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);
if ((error = xfs_btree_check_sblock(cur, left,
cur->bc_nlevels - 1, lbp)))
return error;
nptr = 2;
}
/*
* Fill in the new block's btree header and log it.
*/
new->bb_magic = cpu_to_be32(xfs_magics[cur->bc_btnum]);
new->bb_level = cpu_to_be16(cur->bc_nlevels);
new->bb_numrecs = cpu_to_be16(2);
new->bb_leftsib = cpu_to_be32(NULLAGBLOCK);
new->bb_rightsib = cpu_to_be32(NULLAGBLOCK);
xfs_alloc_log_block(cur->bc_tp, nbp, XFS_BB_ALL_BITS);
ASSERT(lbno != NULLAGBLOCK && rbno != NULLAGBLOCK);
/*
* Fill in the key data in the new root.
*/
{
xfs_alloc_key_t *kp; /* btree key pointer */

kp = XFS_ALLOC_KEY_ADDR(new, 1, cur);
if (be16_to_cpu(left->bb_level) > 0) {
kp[0] = *XFS_ALLOC_KEY_ADDR(left, 1, cur);
kp[1] = *XFS_ALLOC_KEY_ADDR(right, 1, cur);
} else {
xfs_alloc_rec_t *rp; /* btree record pointer */

rp = XFS_ALLOC_REC_ADDR(left, 1, cur);
kp[0].ar_startblock = rp->ar_startblock;
kp[0].ar_blockcount = rp->ar_blockcount;
rp = XFS_ALLOC_REC_ADDR(right, 1, cur);
kp[1].ar_startblock = rp->ar_startblock;
kp[1].ar_blockcount = rp->ar_blockcount;
}
}
xfs_alloc_log_keys(cur, nbp, 1, 2);
/*
* Fill in the pointer data in the new root.
*/
{
xfs_alloc_ptr_t *pp; /* btree address pointer */

pp = XFS_ALLOC_PTR_ADDR(new, 1, cur);
pp[0] = cpu_to_be32(lbno);
pp[1] = cpu_to_be32(rbno);
}
xfs_alloc_log_ptrs(cur, nbp, 1, 2);
/*
* Fix up the cursor.
*/
xfs_btree_setbuf(cur, cur->bc_nlevels, nbp);
cur->bc_ptrs[cur->bc_nlevels] = nptr;
cur->bc_nlevels++;
*stat = 1;
return 0;
}


/*
* Externally visible routines.
Expand Down Expand Up @@ -1244,6 +1088,26 @@ xfs_allocbt_dup_cursor(
cur->bc_btnum);
}

STATIC void
xfs_allocbt_set_root(
struct xfs_btree_cur *cur,
union xfs_btree_ptr *ptr,
int inc)
{
struct xfs_buf *agbp = cur->bc_private.a.agbp;
struct xfs_agf *agf = XFS_BUF_TO_AGF(agbp);
xfs_agnumber_t seqno = be32_to_cpu(agf->agf_seqno);
int btnum = cur->bc_btnum;

ASSERT(ptr->s != 0);

agf->agf_roots[btnum] = ptr->s;
be32_add_cpu(&agf->agf_levels[btnum], inc);
cur->bc_mp->m_perag[seqno].pagf_levels[btnum] += inc;

xfs_alloc_log_agf(cur->bc_tp, agbp, XFS_AGF_ROOTS | XFS_AGF_LEVELS);
}

STATIC int
xfs_allocbt_alloc_block(
struct xfs_btree_cur *cur,
Expand Down Expand Up @@ -1440,6 +1304,7 @@ static const struct xfs_btree_ops xfs_allocbt_ops = {
.key_len = sizeof(xfs_alloc_key_t),

.dup_cursor = xfs_allocbt_dup_cursor,
.set_root = xfs_allocbt_set_root,
.alloc_block = xfs_allocbt_alloc_block,
.update_lastrec = xfs_allocbt_update_lastrec,
.get_maxrecs = xfs_allocbt_get_maxrecs,
Expand Down
129 changes: 129 additions & 0 deletions fs/xfs/xfs_btree.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2467,3 +2467,132 @@ xfs_btree_split(
XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
return error;
}

/*
* Allocate a new root block, fill it in.
*/
int /* error */
xfs_btree_new_root(
struct xfs_btree_cur *cur, /* btree cursor */
int *stat) /* success/failure */
{
struct xfs_btree_block *block; /* one half of the old root block */
struct xfs_buf *bp; /* buffer containing block */
int error; /* error return value */
struct xfs_buf *lbp; /* left buffer pointer */
struct xfs_btree_block *left; /* left btree block */
struct xfs_buf *nbp; /* new (root) buffer */
struct xfs_btree_block *new; /* new (root) btree block */
int nptr; /* new value for key index, 1 or 2 */
struct xfs_buf *rbp; /* right buffer pointer */
struct xfs_btree_block *right; /* right btree block */
union xfs_btree_ptr rptr;
union xfs_btree_ptr lptr;

XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
XFS_BTREE_STATS_INC(cur, newroot);

/* initialise our start point from the cursor */
cur->bc_ops->init_ptr_from_cur(cur, &rptr);

/* Allocate the new block. If we can't do it, we're toast. Give up. */
error = cur->bc_ops->alloc_block(cur, &rptr, &lptr, 1, stat);
if (error)
goto error0;
if (*stat == 0)
goto out0;
XFS_BTREE_STATS_INC(cur, alloc);

/* Set up the new block. */
error = xfs_btree_get_buf_block(cur, &lptr, 0, &new, &nbp);
if (error)
goto error0;

/* Set the root in the holding structure increasing the level by 1. */
cur->bc_ops->set_root(cur, &lptr, 1);

/*
* At the previous root level there are now two blocks: the old root,
* and the new block generated when it was split. We don't know which
* one the cursor is pointing at, so we set up variables "left" and
* "right" for each case.
*/
block = xfs_btree_get_block(cur, cur->bc_nlevels - 1, &bp);

#ifdef DEBUG
error = xfs_btree_check_block(cur, block, cur->bc_nlevels - 1, bp);
if (error)
goto error0;
#endif

xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
if (!xfs_btree_ptr_is_null(cur, &rptr)) {
/* Our block is left, pick up the right block. */
lbp = bp;
xfs_btree_buf_to_ptr(cur, lbp, &lptr);
left = block;
error = xfs_btree_read_buf_block(cur, &rptr,
cur->bc_nlevels - 1, 0, &right, &rbp);
if (error)
goto error0;
bp = rbp;
nptr = 1;
} else {
/* Our block is right, pick up the left block. */
rbp = bp;
xfs_btree_buf_to_ptr(cur, rbp, &rptr);
right = block;
xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
error = xfs_btree_read_buf_block(cur, &lptr,
cur->bc_nlevels - 1, 0, &left, &lbp);
if (error)
goto error0;
bp = lbp;
nptr = 2;
}
/* Fill in the new block's btree header and log it. */
xfs_btree_init_block(cur, cur->bc_nlevels, 2, new);
xfs_btree_log_block(cur, nbp, XFS_BB_ALL_BITS);
ASSERT(!xfs_btree_ptr_is_null(cur, &lptr) &&
!xfs_btree_ptr_is_null(cur, &rptr));

/* Fill in the key data in the new root. */
if (xfs_btree_get_level(left) > 0) {
xfs_btree_copy_keys(cur,
xfs_btree_key_addr(cur, 1, new),
xfs_btree_key_addr(cur, 1, left), 1);
xfs_btree_copy_keys(cur,
xfs_btree_key_addr(cur, 2, new),
xfs_btree_key_addr(cur, 1, right), 1);
} else {
cur->bc_ops->init_key_from_rec(
xfs_btree_key_addr(cur, 1, new),
xfs_btree_rec_addr(cur, 1, left));
cur->bc_ops->init_key_from_rec(
xfs_btree_key_addr(cur, 2, new),
xfs_btree_rec_addr(cur, 1, right));
}
xfs_btree_log_keys(cur, nbp, 1, 2);

/* Fill in the pointer data in the new root. */
xfs_btree_copy_ptrs(cur,
xfs_btree_ptr_addr(cur, 1, new), &lptr, 1);
xfs_btree_copy_ptrs(cur,
xfs_btree_ptr_addr(cur, 2, new), &rptr, 1);
xfs_btree_log_ptrs(cur, nbp, 1, 2);

/* Fix up the cursor. */
xfs_btree_setbuf(cur, cur->bc_nlevels, nbp);
cur->bc_ptrs[cur->bc_nlevels] = nptr;
cur->bc_nlevels++;
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
*stat = 1;
return 0;
error0:
XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
return error;
out0:
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
*stat = 0;
return 0;
}
5 changes: 5 additions & 0 deletions fs/xfs/xfs_btree.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -187,6 +187,10 @@ struct xfs_btree_ops {
/* cursor operations */
struct xfs_btree_cur *(*dup_cursor)(struct xfs_btree_cur *);

/* update btree root pointer */
void (*set_root)(struct xfs_btree_cur *cur,
union xfs_btree_ptr *nptr, int level_change);

/* block allocation / freeing */
int (*alloc_block)(struct xfs_btree_cur *cur,
union xfs_btree_ptr *start_bno,
Expand Down Expand Up @@ -543,6 +547,7 @@ 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 *);
int xfs_btree_new_root(struct xfs_btree_cur *, int *);

/*
* Helpers.
Expand Down
Loading

0 comments on commit 344207c

Please sign in to comment.