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0dc63c8a1c
As we've noted in various places, all current users of in-memory btrees are online fsck. Online fsck only stages a btree long enough to rebuild an ondisk data structure, which means that the in-memory btree is ephemeral. Furthermore, if we encounter /any/ errors while updating an in-memory btree, all we do is tear down all the staged data and return an errno to userspace. In-memory btrees need not be transactional, so their buffers should not be committed to the ondisk log, nor should they be checkpointed by the AIL. That's just as well since the ephemeral nature of the btree means that the buftarg and the buffers may disappear quickly anyway. Therefore, we need a way to launder the btree buffers that get attached to the transaction by the generic btree code. Because the buffers are directly mapped to backing file pages, there's no need to bwrite them back to the tmpfs file. All we need to do is clean enough of the buffer log item state so that the bli can be detached from the buffer, remove the bli from the transaction's log item list, and reset the transaction dirty state as if the laundered items had never been there. For simplicity, create xfbtree transaction commit and cancel helpers that launder the in-memory btree buffers for callers. Once laundered, call the write verifier on non-stale buffers to avoid integrity issues, or punch a hole in the backing file for stale buffers. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
76 lines
2.2 KiB
C
76 lines
2.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Copyright (c) 2021-2024 Oracle. All Rights Reserved.
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* Author: Darrick J. Wong <djwong@kernel.org>
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*/
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#ifndef __XFS_BTREE_MEM_H__
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#define __XFS_BTREE_MEM_H__
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typedef uint64_t xfbno_t;
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#define XFBNO_BLOCKSIZE (XMBUF_BLOCKSIZE)
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#define XFBNO_BBSHIFT (XMBUF_BLOCKSHIFT - BBSHIFT)
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#define XFBNO_BBSIZE (XFBNO_BLOCKSIZE >> BBSHIFT)
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static inline xfs_daddr_t xfbno_to_daddr(xfbno_t blkno)
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{
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return blkno << XFBNO_BBSHIFT;
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}
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static inline xfbno_t xfs_daddr_to_xfbno(xfs_daddr_t daddr)
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{
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return daddr >> XFBNO_BBSHIFT;
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}
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struct xfbtree {
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/* buffer cache target for this in-memory btree */
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struct xfs_buftarg *target;
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/* Highest block number that has been written to. */
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xfbno_t highest_bno;
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/* Owner of this btree. */
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unsigned long long owner;
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/* Btree header */
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union xfs_btree_ptr root;
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unsigned int nlevels;
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/* Minimum and maximum records per block. */
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unsigned int maxrecs[2];
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unsigned int minrecs[2];
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};
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#ifdef CONFIG_XFS_BTREE_IN_MEM
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static inline bool xfbtree_verify_bno(struct xfbtree *xfbt, xfbno_t bno)
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{
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return xmbuf_verify_daddr(xfbt->target, xfbno_to_daddr(bno));
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}
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void xfbtree_set_root(struct xfs_btree_cur *cur,
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const union xfs_btree_ptr *ptr, int inc);
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void xfbtree_init_ptr_from_cur(struct xfs_btree_cur *cur,
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union xfs_btree_ptr *ptr);
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struct xfs_btree_cur *xfbtree_dup_cursor(struct xfs_btree_cur *cur);
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int xfbtree_get_minrecs(struct xfs_btree_cur *cur, int level);
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int xfbtree_get_maxrecs(struct xfs_btree_cur *cur, int level);
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int xfbtree_alloc_block(struct xfs_btree_cur *cur,
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const union xfs_btree_ptr *start, union xfs_btree_ptr *ptr,
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int *stat);
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int xfbtree_free_block(struct xfs_btree_cur *cur, struct xfs_buf *bp);
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/* Callers must set xfbt->target and xfbt->owner before calling this */
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int xfbtree_init(struct xfs_mount *mp, struct xfbtree *xfbt,
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struct xfs_buftarg *btp, const struct xfs_btree_ops *ops);
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void xfbtree_destroy(struct xfbtree *xfbt);
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int xfbtree_trans_commit(struct xfbtree *xfbt, struct xfs_trans *tp);
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void xfbtree_trans_cancel(struct xfbtree *xfbt, struct xfs_trans *tp);
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#else
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# define xfbtree_verify_bno(...) (false)
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#endif /* CONFIG_XFS_BTREE_IN_MEM */
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#endif /* __XFS_BTREE_MEM_H__ */
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