diff options
Diffstat (limited to 'fs/xfs/libxfs/xfs_btree_mem.c')
| -rw-r--r-- | fs/xfs/libxfs/xfs_btree_mem.c | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_btree_mem.c b/fs/xfs/libxfs/xfs_btree_mem.c new file mode 100644 index 000000000000..cb156e9363a5 --- /dev/null +++ b/fs/xfs/libxfs/xfs_btree_mem.c @@ -0,0 +1,228 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (c) 2021-2024 Oracle. All Rights Reserved. + * Author: Darrick J. Wong <djwong@kernel.org> + */ +#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_mount.h" +#include "xfs_trans.h" +#include "xfs_btree.h" +#include "xfs_error.h" +#include "xfs_buf_mem.h" +#include "xfs_btree_mem.h" +#include "xfs_ag.h" +#include "xfs_buf_item.h" +#include "xfs_trace.h" + +/* Set the root of an in-memory btree. */ +void +xfbtree_set_root( + struct xfs_btree_cur *cur, + const union xfs_btree_ptr *ptr, + int inc) +{ + ASSERT(cur->bc_ops->type == XFS_BTREE_TYPE_MEM); + + cur->bc_mem.xfbtree->root = *ptr; + cur->bc_mem.xfbtree->nlevels += inc; +} + +/* Initialize a pointer from the in-memory btree header. */ +void +xfbtree_init_ptr_from_cur( + struct xfs_btree_cur *cur, + union xfs_btree_ptr *ptr) +{ + ASSERT(cur->bc_ops->type == XFS_BTREE_TYPE_MEM); + + *ptr = cur->bc_mem.xfbtree->root; +} + +/* Duplicate an in-memory btree cursor. */ +struct xfs_btree_cur * +xfbtree_dup_cursor( + struct xfs_btree_cur *cur) +{ + struct xfs_btree_cur *ncur; + + ASSERT(cur->bc_ops->type == XFS_BTREE_TYPE_MEM); + + ncur = xfs_btree_alloc_cursor(cur->bc_mp, cur->bc_tp, cur->bc_ops, + cur->bc_maxlevels, cur->bc_cache); + ncur->bc_flags = cur->bc_flags; + ncur->bc_nlevels = cur->bc_nlevels; + ncur->bc_mem.xfbtree = cur->bc_mem.xfbtree; + + if (cur->bc_mem.pag) + ncur->bc_mem.pag = xfs_perag_hold(cur->bc_mem.pag); + + return ncur; +} + +/* Close the btree xfile and release all resources. */ +void +xfbtree_destroy( + struct xfbtree *xfbt) +{ + xfs_buftarg_drain(xfbt->target); +} + +/* Compute the number of bytes available for records. */ +static inline unsigned int +xfbtree_rec_bytes( + struct xfs_mount *mp, + const struct xfs_btree_ops *ops) +{ + return XMBUF_BLOCKSIZE - XFS_BTREE_LBLOCK_CRC_LEN; +} + +/* Initialize an empty leaf block as the btree root. */ +STATIC int +xfbtree_init_leaf_block( + struct xfs_mount *mp, + struct xfbtree *xfbt, + const struct xfs_btree_ops *ops) +{ + struct xfs_buf *bp; + xfbno_t bno = xfbt->highest_bno++; + int error; + + error = xfs_buf_get(xfbt->target, xfbno_to_daddr(bno), XFBNO_BBSIZE, + &bp); + if (error) + return error; + + trace_xfbtree_create_root_buf(xfbt, bp); + + bp->b_ops = ops->buf_ops; + xfs_btree_init_buf(mp, bp, ops, 0, 0, xfbt->owner); + xfs_buf_relse(bp); + + xfbt->root.l = cpu_to_be64(bno); + return 0; +} + +/* + * Create an in-memory btree root that can be used with the given xmbuf. + * Callers must set xfbt->owner. + */ +int +xfbtree_init( + struct xfs_mount *mp, + struct xfbtree *xfbt, + struct xfs_buftarg *btp, + const struct xfs_btree_ops *ops) +{ + unsigned int blocklen = xfbtree_rec_bytes(mp, ops); + unsigned int keyptr_len; + int error; + + /* Requires a long-format CRC-format btree */ + if (!xfs_has_crc(mp)) { + ASSERT(xfs_has_crc(mp)); + return -EINVAL; + } + if (ops->ptr_len != XFS_BTREE_LONG_PTR_LEN) { + ASSERT(ops->ptr_len == XFS_BTREE_LONG_PTR_LEN); + return -EINVAL; + } + + memset(xfbt, 0, sizeof(*xfbt)); + xfbt->target = btp; + + /* Set up min/maxrecs for this btree. */ + keyptr_len = ops->key_len + sizeof(__be64); + xfbt->maxrecs[0] = blocklen / ops->rec_len; + xfbt->maxrecs[1] = blocklen / keyptr_len; + xfbt->minrecs[0] = xfbt->maxrecs[0] / 2; + xfbt->minrecs[1] = xfbt->maxrecs[1] / 2; + xfbt->highest_bno = 0; + xfbt->nlevels = 1; + + /* Initialize the empty btree. */ + error = xfbtree_init_leaf_block(mp, xfbt, ops); + if (error) + goto err_freesp; + + trace_xfbtree_init(mp, xfbt, ops); + + return 0; + +err_freesp: + xfs_buftarg_drain(xfbt->target); + return error; +} + +/* Allocate a block to our in-memory btree. */ +int +xfbtree_alloc_block( + struct xfs_btree_cur *cur, + const union xfs_btree_ptr *start, + union xfs_btree_ptr *new, + int *stat) +{ + struct xfbtree *xfbt = cur->bc_mem.xfbtree; + xfbno_t bno = xfbt->highest_bno++; + + ASSERT(cur->bc_ops->type == XFS_BTREE_TYPE_MEM); + + trace_xfbtree_alloc_block(xfbt, cur, bno); + + /* Fail if the block address exceeds the maximum for the buftarg. */ + if (!xfbtree_verify_bno(xfbt, bno)) { + ASSERT(xfbtree_verify_bno(xfbt, bno)); + *stat = 0; + return 0; + } + + new->l = cpu_to_be64(bno); + *stat = 1; + return 0; +} + +/* Free a block from our in-memory btree. */ +int +xfbtree_free_block( + struct xfs_btree_cur *cur, + struct xfs_buf *bp) +{ + struct xfbtree *xfbt = cur->bc_mem.xfbtree; + xfs_daddr_t daddr = xfs_buf_daddr(bp); + xfbno_t bno = xfs_daddr_to_xfbno(daddr); + + ASSERT(cur->bc_ops->type == XFS_BTREE_TYPE_MEM); + + trace_xfbtree_free_block(xfbt, cur, bno); + + if (bno + 1 == xfbt->highest_bno) + xfbt->highest_bno--; + + return 0; +} + +/* Return the minimum number of records for a btree block. */ +int +xfbtree_get_minrecs( + struct xfs_btree_cur *cur, + int level) +{ + struct xfbtree *xfbt = cur->bc_mem.xfbtree; + + return xfbt->minrecs[level != 0]; +} + +/* Return the maximum number of records for a btree block. */ +int +xfbtree_get_maxrecs( + struct xfs_btree_cur *cur, + int level) +{ + struct xfbtree *xfbt = cur->bc_mem.xfbtree; + + return xfbt->maxrecs[level != 0]; +} |