Staging
v0.8.0
v0.8.0
https://github.com/torvalds/linux
Tip revision: b7bfaa761d760e72a969d116517eaa12e404c262 authored by Linus Torvalds on 08 January 2023, 17:49:43 UTC
Linux 6.2-rc3
Linux 6.2-rc3
Tip revision: b7bfaa7
xfs_btree_staging.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2020 Oracle. All Rights Reserved.
* Author: Darrick J. Wong <darrick.wong@oracle.com>
*/
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_bit.h"
#include "xfs_mount.h"
#include "xfs_inode.h"
#include "xfs_trans.h"
#include "xfs_btree.h"
#include "xfs_trace.h"
#include "xfs_btree_staging.h"
/*
* Staging Cursors and Fake Roots for Btrees
* =========================================
*
* A staging btree cursor is a special type of btree cursor that callers must
* use to construct a new btree index using the btree bulk loader code. The
* bulk loading code uses the staging btree cursor to abstract the details of
* initializing new btree blocks and filling them with records or key/ptr
* pairs. Regular btree operations (e.g. queries and modifications) are not
* supported with staging cursors, and callers must not invoke them.
*
* Fake root structures contain all the information about a btree that is under
* construction by the bulk loading code. Staging btree cursors point to fake
* root structures instead of the usual AG header or inode structure.
*
* Callers are expected to initialize a fake root structure and pass it into
* the _stage_cursor function for a specific btree type. When bulk loading is
* complete, callers should call the _commit_staged_btree function for that
* specific btree type to commit the new btree into the filesystem.
*/
/*
* Don't allow staging cursors to be duplicated because they're supposed to be
* kept private to a single thread.
*/
STATIC struct xfs_btree_cur *
xfs_btree_fakeroot_dup_cursor(
struct xfs_btree_cur *cur)
{
ASSERT(0);
return NULL;
}
/*
* Don't allow block allocation for a staging cursor, because staging cursors
* do not support regular btree modifications.
*
* Bulk loading uses a separate callback to obtain new blocks from a
* preallocated list, which prevents ENOSPC failures during loading.
*/
STATIC int
xfs_btree_fakeroot_alloc_block(
struct xfs_btree_cur *cur,
const union xfs_btree_ptr *start_bno,
union xfs_btree_ptr *new_bno,
int *stat)
{
ASSERT(0);
return -EFSCORRUPTED;
}
/*
* Don't allow block freeing for a staging cursor, because staging cursors
* do not support regular btree modifications.
*/
STATIC int
xfs_btree_fakeroot_free_block(
struct xfs_btree_cur *cur,
struct xfs_buf *bp)
{
ASSERT(0);
return -EFSCORRUPTED;
}
/* Initialize a pointer to the root block from the fakeroot. */
STATIC void
xfs_btree_fakeroot_init_ptr_from_cur(
struct xfs_btree_cur *cur,
union xfs_btree_ptr *ptr)
{
struct xbtree_afakeroot *afake;
ASSERT(cur->bc_flags & XFS_BTREE_STAGING);
afake = cur->bc_ag.afake;
ptr->s = cpu_to_be32(afake->af_root);
}
/*
* Bulk Loading for AG Btrees
* ==========================
*
* For a btree rooted in an AG header, pass a xbtree_afakeroot structure to the
* staging cursor. Callers should initialize this to zero.
*
* The _stage_cursor() function for a specific btree type should call
* xfs_btree_stage_afakeroot to set up the in-memory cursor as a staging
* cursor. The corresponding _commit_staged_btree() function should log the
* new root and call xfs_btree_commit_afakeroot() to transform the staging
* cursor into a regular btree cursor.
*/
/* Update the btree root information for a per-AG fake root. */
STATIC void
xfs_btree_afakeroot_set_root(
struct xfs_btree_cur *cur,
const union xfs_btree_ptr *ptr,
int inc)
{
struct xbtree_afakeroot *afake = cur->bc_ag.afake;
ASSERT(cur->bc_flags & XFS_BTREE_STAGING);
afake->af_root = be32_to_cpu(ptr->s);
afake->af_levels += inc;
}
/*
* Initialize a AG-rooted btree cursor with the given AG btree fake root.
* The btree cursor's bc_ops will be overridden as needed to make the staging
* functionality work.
*/
void
xfs_btree_stage_afakeroot(
struct xfs_btree_cur *cur,
struct xbtree_afakeroot *afake)
{
struct xfs_btree_ops *nops;
ASSERT(!(cur->bc_flags & XFS_BTREE_STAGING));
ASSERT(!(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE));
ASSERT(cur->bc_tp == NULL);
nops = kmem_alloc(sizeof(struct xfs_btree_ops), KM_NOFS);
memcpy(nops, cur->bc_ops, sizeof(struct xfs_btree_ops));
nops->alloc_block = xfs_btree_fakeroot_alloc_block;
nops->free_block = xfs_btree_fakeroot_free_block;
nops->init_ptr_from_cur = xfs_btree_fakeroot_init_ptr_from_cur;
nops->set_root = xfs_btree_afakeroot_set_root;
nops->dup_cursor = xfs_btree_fakeroot_dup_cursor;
cur->bc_ag.afake = afake;
cur->bc_nlevels = afake->af_levels;
cur->bc_ops = nops;
cur->bc_flags |= XFS_BTREE_STAGING;
}
/*
* Transform an AG-rooted staging btree cursor back into a regular cursor by
* substituting a real btree root for the fake one and restoring normal btree
* cursor ops. The caller must log the btree root change prior to calling
* this.
*/
void
xfs_btree_commit_afakeroot(
struct xfs_btree_cur *cur,
struct xfs_trans *tp,
struct xfs_buf *agbp,
const struct xfs_btree_ops *ops)
{
ASSERT(cur->bc_flags & XFS_BTREE_STAGING);
ASSERT(cur->bc_tp == NULL);
trace_xfs_btree_commit_afakeroot(cur);
kmem_free((void *)cur->bc_ops);
cur->bc_ag.agbp = agbp;
cur->bc_ops = ops;
cur->bc_flags &= ~XFS_BTREE_STAGING;
cur->bc_tp = tp;
}
/*
* Bulk Loading for Inode-Rooted Btrees
* ====================================
*
* For a btree rooted in an inode fork, pass a xbtree_ifakeroot structure to
* the staging cursor. This structure should be initialized as follows:
*
* - if_fork_size field should be set to the number of bytes available to the
* fork in the inode.
*
* - if_fork should point to a freshly allocated struct xfs_ifork.
*
* - if_format should be set to the appropriate fork type (e.g.
* XFS_DINODE_FMT_BTREE).
*
* All other fields must be zero.
*
* The _stage_cursor() function for a specific btree type should call
* xfs_btree_stage_ifakeroot to set up the in-memory cursor as a staging
* cursor. The corresponding _commit_staged_btree() function should log the
* new root and call xfs_btree_commit_ifakeroot() to transform the staging
* cursor into a regular btree cursor.
*/
/*
* Initialize an inode-rooted btree cursor with the given inode btree fake
* root. The btree cursor's bc_ops will be overridden as needed to make the
* staging functionality work. If new_ops is not NULL, these new ops will be
* passed out to the caller for further overriding.
*/
void
xfs_btree_stage_ifakeroot(
struct xfs_btree_cur *cur,
struct xbtree_ifakeroot *ifake,
struct xfs_btree_ops **new_ops)
{
struct xfs_btree_ops *nops;
ASSERT(!(cur->bc_flags & XFS_BTREE_STAGING));
ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
ASSERT(cur->bc_tp == NULL);
nops = kmem_alloc(sizeof(struct xfs_btree_ops), KM_NOFS);
memcpy(nops, cur->bc_ops, sizeof(struct xfs_btree_ops));
nops->alloc_block = xfs_btree_fakeroot_alloc_block;
nops->free_block = xfs_btree_fakeroot_free_block;
nops->init_ptr_from_cur = xfs_btree_fakeroot_init_ptr_from_cur;
nops->dup_cursor = xfs_btree_fakeroot_dup_cursor;
cur->bc_ino.ifake = ifake;
cur->bc_nlevels = ifake->if_levels;
cur->bc_ops = nops;
cur->bc_flags |= XFS_BTREE_STAGING;
if (new_ops)
*new_ops = nops;
}
/*
* Transform an inode-rooted staging btree cursor back into a regular cursor by
* substituting a real btree root for the fake one and restoring normal btree
* cursor ops. The caller must log the btree root change prior to calling
* this.
*/
void
xfs_btree_commit_ifakeroot(
struct xfs_btree_cur *cur,
struct xfs_trans *tp,
int whichfork,
const struct xfs_btree_ops *ops)
{
ASSERT(cur->bc_flags & XFS_BTREE_STAGING);
ASSERT(cur->bc_tp == NULL);
trace_xfs_btree_commit_ifakeroot(cur);
kmem_free((void *)cur->bc_ops);
cur->bc_ino.ifake = NULL;
cur->bc_ino.whichfork = whichfork;
cur->bc_ops = ops;
cur->bc_flags &= ~XFS_BTREE_STAGING;
cur->bc_tp = tp;
}
/*
* Bulk Loading of Staged Btrees
* =============================
*
* This interface is used with a staged btree cursor to create a totally new
* btree with a large number of records (i.e. more than what would fit in a
* single root block). When the creation is complete, the new root can be
* linked atomically into the filesystem by committing the staged cursor.
*
* Creation of a new btree proceeds roughly as follows:
*
* The first step is to initialize an appropriate fake btree root structure and
* then construct a staged btree cursor. Refer to the block comments about
* "Bulk Loading for AG Btrees" and "Bulk Loading for Inode-Rooted Btrees" for
* more information about how to do this.
*
* The second step is to initialize a struct xfs_btree_bload context as
* documented in the structure definition.
*
* The third step is to call xfs_btree_bload_compute_geometry to compute the
* height of and the number of blocks needed to construct the btree. See the
* section "Computing the Geometry of the New Btree" for details about this
* computation.
*
* In step four, the caller must allocate xfs_btree_bload.nr_blocks blocks and
* save them for later use by ->claim_block(). Bulk loading requires all
* blocks to be allocated beforehand to avoid ENOSPC failures midway through a
* rebuild, and to minimize seek distances of the new btree.
*
* Step five is to call xfs_btree_bload() to start constructing the btree.
*
* The final step is to commit the staging btree cursor, which logs the new
* btree root and turns the staging cursor into a regular cursor. The caller
* is responsible for cleaning up the previous btree blocks, if any.
*
* Computing the Geometry of the New Btree
* =======================================
*
* The number of items placed in each btree block is computed via the following
* algorithm: For leaf levels, the number of items for the level is nr_records
* in the bload structure. For node levels, the number of items for the level
* is the number of blocks in the next lower level of the tree. For each
* level, the desired number of items per block is defined as:
*
* desired = max(minrecs, maxrecs - slack factor)
*
* The number of blocks for the level is defined to be:
*
* blocks = floor(nr_items / desired)
*
* Note this is rounded down so that the npb calculation below will never fall
* below minrecs. The number of items that will actually be loaded into each
* btree block is defined as:
*
* npb = nr_items / blocks
*
* Some of the leftmost blocks in the level will contain one extra record as
* needed to handle uneven division. If the number of records in any block
* would exceed maxrecs for that level, blocks is incremented and npb is
* recalculated.
*
* In other words, we compute the number of blocks needed to satisfy a given
* loading level, then spread the items as evenly as possible.
*
* The height and number of fs blocks required to create the btree are computed
* and returned via btree_height and nr_blocks.
*/
/*
* Put a btree block that we're loading onto the ordered list and release it.
* The btree blocks will be written to disk when bulk loading is finished.
*/
static void
xfs_btree_bload_drop_buf(
struct list_head *buffers_list,
struct xfs_buf **bpp)
{
if (*bpp == NULL)
return;
if (!xfs_buf_delwri_queue(*bpp, buffers_list))
ASSERT(0);
xfs_buf_relse(*bpp);
*bpp = NULL;
}
/*
* Allocate and initialize one btree block for bulk loading.
*
* The new btree block will have its level and numrecs fields set to the values
* of the level and nr_this_block parameters, respectively.
*
* The caller should ensure that ptrp, bpp, and blockp refer to the left
* sibling of the new block, if there is any. On exit, ptrp, bpp, and blockp
* will all point to the new block.
*/
STATIC int
xfs_btree_bload_prep_block(
struct xfs_btree_cur *cur,
struct xfs_btree_bload *bbl,
struct list_head *buffers_list,
unsigned int level,
unsigned int nr_this_block,
union xfs_btree_ptr *ptrp, /* in/out */
struct xfs_buf **bpp, /* in/out */
struct xfs_btree_block **blockp, /* in/out */
void *priv)
{
union xfs_btree_ptr new_ptr;
struct xfs_buf *new_bp;
struct xfs_btree_block *new_block;
int ret;
if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
level == cur->bc_nlevels - 1) {
struct xfs_ifork *ifp = xfs_btree_ifork_ptr(cur);
size_t new_size;
ASSERT(*bpp == NULL);
/* Allocate a new incore btree root block. */
new_size = bbl->iroot_size(cur, nr_this_block, priv);
ifp->if_broot = kmem_zalloc(new_size, 0);
ifp->if_broot_bytes = (int)new_size;
/* Initialize it and send it out. */
xfs_btree_init_block_int(cur->bc_mp, ifp->if_broot,
XFS_BUF_DADDR_NULL, cur->bc_btnum, level,
nr_this_block, cur->bc_ino.ip->i_ino,
cur->bc_flags);
*bpp = NULL;
*blockp = ifp->if_broot;
xfs_btree_set_ptr_null(cur, ptrp);
return 0;
}
/* Claim one of the caller's preallocated blocks. */
xfs_btree_set_ptr_null(cur, &new_ptr);
ret = bbl->claim_block(cur, &new_ptr, priv);
if (ret)
return ret;
ASSERT(!xfs_btree_ptr_is_null(cur, &new_ptr));
ret = xfs_btree_get_buf_block(cur, &new_ptr, &new_block, &new_bp);
if (ret)
return ret;
/*
* The previous block (if any) is the left sibling of the new block,
* so set its right sibling pointer to the new block and drop it.
*/
if (*blockp)
xfs_btree_set_sibling(cur, *blockp, &new_ptr, XFS_BB_RIGHTSIB);
xfs_btree_bload_drop_buf(buffers_list, bpp);
/* Initialize the new btree block. */
xfs_btree_init_block_cur(cur, new_bp, level, nr_this_block);
xfs_btree_set_sibling(cur, new_block, ptrp, XFS_BB_LEFTSIB);
/* Set the out parameters. */
*bpp = new_bp;
*blockp = new_block;
xfs_btree_copy_ptrs(cur, ptrp, &new_ptr, 1);
return 0;
}
/* Load one leaf block. */
STATIC int
xfs_btree_bload_leaf(
struct xfs_btree_cur *cur,
unsigned int recs_this_block,
xfs_btree_bload_get_record_fn get_record,
struct xfs_btree_block *block,
void *priv)
{
unsigned int j;
int ret;
/* Fill the leaf block with records. */
for (j = 1; j <= recs_this_block; j++) {
union xfs_btree_rec *block_rec;
ret = get_record(cur, priv);
if (ret)
return ret;
block_rec = xfs_btree_rec_addr(cur, j, block);
cur->bc_ops->init_rec_from_cur(cur, block_rec);
}
return 0;
}
/*
* Load one node block with key/ptr pairs.
*
* child_ptr must point to a block within the next level down in the tree. A
* key/ptr entry will be created in the new node block to the block pointed to
* by child_ptr. On exit, child_ptr points to the next block on the child
* level that needs processing.
*/
STATIC int
xfs_btree_bload_node(
struct xfs_btree_cur *cur,
unsigned int recs_this_block,
union xfs_btree_ptr *child_ptr,
struct xfs_btree_block *block)
{
unsigned int j;
int ret;
/* Fill the node block with keys and pointers. */
for (j = 1; j <= recs_this_block; j++) {
union xfs_btree_key child_key;
union xfs_btree_ptr *block_ptr;
union xfs_btree_key *block_key;
struct xfs_btree_block *child_block;
struct xfs_buf *child_bp;
ASSERT(!xfs_btree_ptr_is_null(cur, child_ptr));
ret = xfs_btree_get_buf_block(cur, child_ptr, &child_block,
&child_bp);
if (ret)
return ret;
block_ptr = xfs_btree_ptr_addr(cur, j, block);
xfs_btree_copy_ptrs(cur, block_ptr, child_ptr, 1);
block_key = xfs_btree_key_addr(cur, j, block);
xfs_btree_get_keys(cur, child_block, &child_key);
xfs_btree_copy_keys(cur, block_key, &child_key, 1);
xfs_btree_get_sibling(cur, child_block, child_ptr,
XFS_BB_RIGHTSIB);
xfs_buf_relse(child_bp);
}
return 0;
}
/*
* Compute the maximum number of records (or keyptrs) per block that we want to
* install at this level in the btree. Caller is responsible for having set
* @cur->bc_ino.forksize to the desired fork size, if appropriate.
*/
STATIC unsigned int
xfs_btree_bload_max_npb(
struct xfs_btree_cur *cur,
struct xfs_btree_bload *bbl,
unsigned int level)
{
unsigned int ret;
if (level == cur->bc_nlevels - 1 && cur->bc_ops->get_dmaxrecs)
return cur->bc_ops->get_dmaxrecs(cur, level);
ret = cur->bc_ops->get_maxrecs(cur, level);
if (level == 0)
ret -= bbl->leaf_slack;
else
ret -= bbl->node_slack;
return ret;
}
/*
* Compute the desired number of records (or keyptrs) per block that we want to
* install at this level in the btree, which must be somewhere between minrecs
* and max_npb. The caller is free to install fewer records per block.
*/
STATIC unsigned int
xfs_btree_bload_desired_npb(
struct xfs_btree_cur *cur,
struct xfs_btree_bload *bbl,
unsigned int level)
{
unsigned int npb = xfs_btree_bload_max_npb(cur, bbl, level);
/* Root blocks are not subject to minrecs rules. */
if (level == cur->bc_nlevels - 1)
return max(1U, npb);
return max_t(unsigned int, cur->bc_ops->get_minrecs(cur, level), npb);
}
/*
* Compute the number of records to be stored in each block at this level and
* the number of blocks for this level. For leaf levels, we must populate an
* empty root block even if there are no records, so we have to have at least
* one block.
*/
STATIC void
xfs_btree_bload_level_geometry(
struct xfs_btree_cur *cur,
struct xfs_btree_bload *bbl,
unsigned int level,
uint64_t nr_this_level,
unsigned int *avg_per_block,
uint64_t *blocks,
uint64_t *blocks_with_extra)
{
uint64_t npb;
uint64_t dontcare;
unsigned int desired_npb;
unsigned int maxnr;
maxnr = cur->bc_ops->get_maxrecs(cur, level);
/*
* Compute the number of blocks we need to fill each block with the
* desired number of records/keyptrs per block. Because desired_npb
* could be minrecs, we use regular integer division (which rounds
* the block count down) so that in the next step the effective # of
* items per block will never be less than desired_npb.
*/
desired_npb = xfs_btree_bload_desired_npb(cur, bbl, level);
*blocks = div64_u64_rem(nr_this_level, desired_npb, &dontcare);
*blocks = max(1ULL, *blocks);
/*
* Compute the number of records that we will actually put in each
* block, assuming that we want to spread the records evenly between
* the blocks. Take care that the effective # of items per block (npb)
* won't exceed maxrecs even for the blocks that get an extra record,
* since desired_npb could be maxrecs, and in the previous step we
* rounded the block count down.
*/
npb = div64_u64_rem(nr_this_level, *blocks, blocks_with_extra);
if (npb > maxnr || (npb == maxnr && *blocks_with_extra > 0)) {
(*blocks)++;
npb = div64_u64_rem(nr_this_level, *blocks, blocks_with_extra);
}
*avg_per_block = min_t(uint64_t, npb, nr_this_level);
trace_xfs_btree_bload_level_geometry(cur, level, nr_this_level,
*avg_per_block, desired_npb, *blocks,
*blocks_with_extra);
}
/*
* Ensure a slack value is appropriate for the btree.
*
* If the slack value is negative, set slack so that we fill the block to
* halfway between minrecs and maxrecs. Make sure the slack is never so large
* that we can underflow minrecs.
*/
static void
xfs_btree_bload_ensure_slack(
struct xfs_btree_cur *cur,
int *slack,
int level)
{
int maxr;
int minr;
maxr = cur->bc_ops->get_maxrecs(cur, level);
minr = cur->bc_ops->get_minrecs(cur, level);
/*
* If slack is negative, automatically set slack so that we load the
* btree block approximately halfway between minrecs and maxrecs.
* Generally, this will net us 75% loading.
*/
if (*slack < 0)
*slack = maxr - ((maxr + minr) >> 1);
*slack = min(*slack, maxr - minr);
}
/*
* Prepare a btree cursor for a bulk load operation by computing the geometry
* fields in bbl. Caller must ensure that the btree cursor is a staging
* cursor. This function can be called multiple times.
*/
int
xfs_btree_bload_compute_geometry(
struct xfs_btree_cur *cur,
struct xfs_btree_bload *bbl,
uint64_t nr_records)
{
uint64_t nr_blocks = 0;
uint64_t nr_this_level;
ASSERT(cur->bc_flags & XFS_BTREE_STAGING);
/*
* Make sure that the slack values make sense for traditional leaf and
* node blocks. Inode-rooted btrees will return different minrecs and
* maxrecs values for the root block (bc_nlevels == level - 1). We're
* checking levels 0 and 1 here, so set bc_nlevels such that the btree
* code doesn't interpret either as the root level.
*/
cur->bc_nlevels = cur->bc_maxlevels - 1;
xfs_btree_bload_ensure_slack(cur, &bbl->leaf_slack, 0);
xfs_btree_bload_ensure_slack(cur, &bbl->node_slack, 1);
bbl->nr_records = nr_this_level = nr_records;
for (cur->bc_nlevels = 1; cur->bc_nlevels <= cur->bc_maxlevels;) {
uint64_t level_blocks;
uint64_t dontcare64;
unsigned int level = cur->bc_nlevels - 1;
unsigned int avg_per_block;
xfs_btree_bload_level_geometry(cur, bbl, level, nr_this_level,
&avg_per_block, &level_blocks, &dontcare64);
if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) {
/*
* If all the items we want to store at this level
* would fit in the inode root block, then we have our
* btree root and are done.
*
* Note that bmap btrees forbid records in the root.
*/
if (level != 0 && nr_this_level <= avg_per_block) {
nr_blocks++;
break;
}
/*
* Otherwise, we have to store all the items for this
* level in traditional btree blocks and therefore need
* another level of btree to point to those blocks.
*
* We have to re-compute the geometry for each level of
* an inode-rooted btree because the geometry differs
* between a btree root in an inode fork and a
* traditional btree block.
*
* This distinction is made in the btree code based on
* whether level == bc_nlevels - 1. Based on the
* previous root block size check against the root
* block geometry, we know that we aren't yet ready to
* populate the root. Increment bc_nevels and
* recalculate the geometry for a traditional
* block-based btree level.
*/
cur->bc_nlevels++;
ASSERT(cur->bc_nlevels <= cur->bc_maxlevels);
xfs_btree_bload_level_geometry(cur, bbl, level,
nr_this_level, &avg_per_block,
&level_blocks, &dontcare64);
} else {
/*
* If all the items we want to store at this level
* would fit in a single root block, we're done.
*/
if (nr_this_level <= avg_per_block) {
nr_blocks++;
break;
}
/* Otherwise, we need another level of btree. */
cur->bc_nlevels++;
ASSERT(cur->bc_nlevels <= cur->bc_maxlevels);
}
nr_blocks += level_blocks;
nr_this_level = level_blocks;
}
if (cur->bc_nlevels > cur->bc_maxlevels)
return -EOVERFLOW;
bbl->btree_height = cur->bc_nlevels;
if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE)
bbl->nr_blocks = nr_blocks - 1;
else
bbl->nr_blocks = nr_blocks;
return 0;
}
/* Bulk load a btree given the parameters and geometry established in bbl. */
int
xfs_btree_bload(
struct xfs_btree_cur *cur,
struct xfs_btree_bload *bbl,
void *priv)
{
struct list_head buffers_list;
union xfs_btree_ptr child_ptr;
union xfs_btree_ptr ptr;
struct xfs_buf *bp = NULL;
struct xfs_btree_block *block = NULL;
uint64_t nr_this_level = bbl->nr_records;
uint64_t blocks;
uint64_t i;
uint64_t blocks_with_extra;
uint64_t total_blocks = 0;
unsigned int avg_per_block;
unsigned int level = 0;
int ret;
ASSERT(cur->bc_flags & XFS_BTREE_STAGING);
INIT_LIST_HEAD(&buffers_list);
cur->bc_nlevels = bbl->btree_height;
xfs_btree_set_ptr_null(cur, &child_ptr);
xfs_btree_set_ptr_null(cur, &ptr);
xfs_btree_bload_level_geometry(cur, bbl, level, nr_this_level,
&avg_per_block, &blocks, &blocks_with_extra);
/* Load each leaf block. */
for (i = 0; i < blocks; i++) {
unsigned int nr_this_block = avg_per_block;
/*
* Due to rounding, btree blocks will not be evenly populated
* in most cases. blocks_with_extra tells us how many blocks
* will receive an extra record to distribute the excess across
* the current level as evenly as possible.
*/
if (i < blocks_with_extra)
nr_this_block++;
ret = xfs_btree_bload_prep_block(cur, bbl, &buffers_list, level,
nr_this_block, &ptr, &bp, &block, priv);
if (ret)
goto out;
trace_xfs_btree_bload_block(cur, level, i, blocks, &ptr,
nr_this_block);
ret = xfs_btree_bload_leaf(cur, nr_this_block, bbl->get_record,
block, priv);
if (ret)
goto out;
/*
* Record the leftmost leaf pointer so we know where to start
* with the first node level.
*/
if (i == 0)
xfs_btree_copy_ptrs(cur, &child_ptr, &ptr, 1);
}
total_blocks += blocks;
xfs_btree_bload_drop_buf(&buffers_list, &bp);
/* Populate the internal btree nodes. */
for (level = 1; level < cur->bc_nlevels; level++) {
union xfs_btree_ptr first_ptr;
nr_this_level = blocks;
block = NULL;
xfs_btree_set_ptr_null(cur, &ptr);
xfs_btree_bload_level_geometry(cur, bbl, level, nr_this_level,
&avg_per_block, &blocks, &blocks_with_extra);
/* Load each node block. */
for (i = 0; i < blocks; i++) {
unsigned int nr_this_block = avg_per_block;
if (i < blocks_with_extra)
nr_this_block++;
ret = xfs_btree_bload_prep_block(cur, bbl,
&buffers_list, level, nr_this_block,
&ptr, &bp, &block, priv);
if (ret)
goto out;
trace_xfs_btree_bload_block(cur, level, i, blocks,
&ptr, nr_this_block);
ret = xfs_btree_bload_node(cur, nr_this_block,
&child_ptr, block);
if (ret)
goto out;
/*
* Record the leftmost node pointer so that we know
* where to start the next node level above this one.
*/
if (i == 0)
xfs_btree_copy_ptrs(cur, &first_ptr, &ptr, 1);
}
total_blocks += blocks;
xfs_btree_bload_drop_buf(&buffers_list, &bp);
xfs_btree_copy_ptrs(cur, &child_ptr, &first_ptr, 1);
}
/* Initialize the new root. */
if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) {
ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
cur->bc_ino.ifake->if_levels = cur->bc_nlevels;
cur->bc_ino.ifake->if_blocks = total_blocks - 1;
} else {
cur->bc_ag.afake->af_root = be32_to_cpu(ptr.s);
cur->bc_ag.afake->af_levels = cur->bc_nlevels;
cur->bc_ag.afake->af_blocks = total_blocks;
}
/*
* Write the new blocks to disk. If the ordered list isn't empty after
* that, then something went wrong and we have to fail. This should
* never happen, but we'll check anyway.
*/
ret = xfs_buf_delwri_submit(&buffers_list);
if (ret)
goto out;
if (!list_empty(&buffers_list)) {
ASSERT(list_empty(&buffers_list));
ret = -EIO;
}
out:
xfs_buf_delwri_cancel(&buffers_list);
if (bp)
xfs_buf_relse(bp);
return ret;
}