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Diffstat (limited to 'fs/xfs/libxfs/xfs_btree_staging.c')
-rw-r--r-- | fs/xfs/libxfs/xfs_btree_staging.c | 880 |
1 files changed, 880 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_btree_staging.c b/fs/xfs/libxfs/xfs_btree_staging.c new file mode 100644 index 0000000000..dd75e208b5 --- /dev/null +++ b/fs/xfs/libxfs/xfs_btree_staging.c @@ -0,0 +1,880 @@ +// 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; +} |