From: Darrick J. Wong Date: Thu, 23 Sep 2021 17:32:06 +0000 (-0700) Subject: xfs: compute absolute maximum nlevels for each btree type X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=0ed5f7356daee74244b02e100b3cc043e886e686;p=linux.git xfs: compute absolute maximum nlevels for each btree type Add code for all five btree types so that we can compute the absolute maximum possible btree height for each btree type. This is a setup for the next patch, which makes every btree type have its own cursor cache. The functions are exported so that we can have xfs_db report the absolute maximum btree heights for each btree type, rather than making everyone run their own ad-hoc computations. Signed-off-by: Darrick J. Wong Reviewed-by: Dave Chinner --- diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c index 2efb4f4539f12..1a5684af84307 100644 --- a/fs/xfs/libxfs/xfs_alloc.c +++ b/fs/xfs/libxfs/xfs_alloc.c @@ -2198,6 +2198,7 @@ xfs_alloc_compute_maxlevels( { mp->m_alloc_maxlevels = xfs_btree_compute_maxlevels(mp->m_alloc_mnr, (mp->m_sb.sb_agblocks + 1) / 2); + ASSERT(mp->m_alloc_maxlevels <= xfs_allocbt_maxlevels_ondisk()); } /* diff --git a/fs/xfs/libxfs/xfs_alloc_btree.c b/fs/xfs/libxfs/xfs_alloc_btree.c index c3e262290f6fe..d0a7aa4b52a80 100644 --- a/fs/xfs/libxfs/xfs_alloc_btree.c +++ b/fs/xfs/libxfs/xfs_alloc_btree.c @@ -566,6 +566,17 @@ xfs_allocbt_commit_staged_btree( } } +/* Calculate number of records in an alloc btree block. */ +static inline unsigned int +xfs_allocbt_block_maxrecs( + unsigned int blocklen, + bool leaf) +{ + if (leaf) + return blocklen / sizeof(xfs_alloc_rec_t); + return blocklen / (sizeof(xfs_alloc_key_t) + sizeof(xfs_alloc_ptr_t)); +} + /* * Calculate number of records in an alloc btree block. */ @@ -576,10 +587,26 @@ xfs_allocbt_maxrecs( int leaf) { blocklen -= XFS_ALLOC_BLOCK_LEN(mp); + return xfs_allocbt_block_maxrecs(blocklen, leaf); +} - if (leaf) - return blocklen / sizeof(xfs_alloc_rec_t); - return blocklen / (sizeof(xfs_alloc_key_t) + sizeof(xfs_alloc_ptr_t)); +/* Free space btrees are at their largest when every other block is free. */ +#define XFS_MAX_FREESP_RECORDS ((XFS_MAX_AG_BLOCKS + 1) / 2) + +/* Compute the max possible height for free space btrees. */ +unsigned int +xfs_allocbt_maxlevels_ondisk(void) +{ + unsigned int minrecs[2]; + unsigned int blocklen; + + blocklen = min(XFS_MIN_BLOCKSIZE - XFS_BTREE_SBLOCK_LEN, + XFS_MIN_CRC_BLOCKSIZE - XFS_BTREE_SBLOCK_CRC_LEN); + + minrecs[0] = xfs_allocbt_block_maxrecs(blocklen, true) / 2; + minrecs[1] = xfs_allocbt_block_maxrecs(blocklen, false) / 2; + + return xfs_btree_compute_maxlevels(minrecs, XFS_MAX_FREESP_RECORDS); } /* Calculate the freespace btree size for some records. */ diff --git a/fs/xfs/libxfs/xfs_alloc_btree.h b/fs/xfs/libxfs/xfs_alloc_btree.h index 2f6b816aaf9f1..c715bee5ae90b 100644 --- a/fs/xfs/libxfs/xfs_alloc_btree.h +++ b/fs/xfs/libxfs/xfs_alloc_btree.h @@ -60,4 +60,6 @@ extern xfs_extlen_t xfs_allocbt_calc_size(struct xfs_mount *mp, void xfs_allocbt_commit_staged_btree(struct xfs_btree_cur *cur, struct xfs_trans *tp, struct xfs_buf *agbp); +unsigned int xfs_allocbt_maxlevels_ondisk(void); + #endif /* __XFS_ALLOC_BTREE_H__ */ diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c index 2ae5bf9a74e7a..321617e837ef2 100644 --- a/fs/xfs/libxfs/xfs_bmap.c +++ b/fs/xfs/libxfs/xfs_bmap.c @@ -93,6 +93,7 @@ xfs_bmap_compute_maxlevels( maxblocks = (maxblocks + minnoderecs - 1) / minnoderecs; } mp->m_bm_maxlevels[whichfork] = level; + ASSERT(mp->m_bm_maxlevels[whichfork] <= xfs_bmbt_maxlevels_ondisk()); } unsigned int diff --git a/fs/xfs/libxfs/xfs_bmap_btree.c b/fs/xfs/libxfs/xfs_bmap_btree.c index b90122de0df0a..59d146696a620 100644 --- a/fs/xfs/libxfs/xfs_bmap_btree.c +++ b/fs/xfs/libxfs/xfs_bmap_btree.c @@ -571,6 +571,17 @@ xfs_bmbt_init_cursor( return cur; } +/* Calculate number of records in a block mapping btree block. */ +static inline unsigned int +xfs_bmbt_block_maxrecs( + unsigned int blocklen, + bool leaf) +{ + if (leaf) + return blocklen / sizeof(xfs_bmbt_rec_t); + return blocklen / (sizeof(xfs_bmbt_key_t) + sizeof(xfs_bmbt_ptr_t)); +} + /* * Calculate number of records in a bmap btree block. */ @@ -581,10 +592,24 @@ xfs_bmbt_maxrecs( int leaf) { blocklen -= XFS_BMBT_BLOCK_LEN(mp); + return xfs_bmbt_block_maxrecs(blocklen, leaf); +} - if (leaf) - return blocklen / sizeof(xfs_bmbt_rec_t); - return blocklen / (sizeof(xfs_bmbt_key_t) + sizeof(xfs_bmbt_ptr_t)); +/* Compute the max possible height for block mapping btrees. */ +unsigned int +xfs_bmbt_maxlevels_ondisk(void) +{ + unsigned int minrecs[2]; + unsigned int blocklen; + + blocklen = min(XFS_MIN_BLOCKSIZE - XFS_BTREE_SBLOCK_LEN, + XFS_MIN_CRC_BLOCKSIZE - XFS_BTREE_SBLOCK_CRC_LEN); + + minrecs[0] = xfs_bmbt_block_maxrecs(blocklen, true) / 2; + minrecs[1] = xfs_bmbt_block_maxrecs(blocklen, false) / 2; + + /* One extra level for the inode root. */ + return xfs_btree_compute_maxlevels(minrecs, MAXEXTNUM) + 1; } /* diff --git a/fs/xfs/libxfs/xfs_bmap_btree.h b/fs/xfs/libxfs/xfs_bmap_btree.h index 729e3bc569be7..2a1c9e607b52e 100644 --- a/fs/xfs/libxfs/xfs_bmap_btree.h +++ b/fs/xfs/libxfs/xfs_bmap_btree.h @@ -110,4 +110,6 @@ extern struct xfs_btree_cur *xfs_bmbt_init_cursor(struct xfs_mount *, extern unsigned long long xfs_bmbt_calc_size(struct xfs_mount *mp, unsigned long long len); +unsigned int xfs_bmbt_maxlevels_ondisk(void); + #endif /* __XFS_BMAP_BTREE_H__ */ diff --git a/fs/xfs/libxfs/xfs_fs.h b/fs/xfs/libxfs/xfs_fs.h index bde2b4c64dbe3..c43877c8a279f 100644 --- a/fs/xfs/libxfs/xfs_fs.h +++ b/fs/xfs/libxfs/xfs_fs.h @@ -268,6 +268,8 @@ typedef struct xfs_fsop_resblks { */ #define XFS_MIN_AG_BYTES (1ULL << 24) /* 16 MB */ #define XFS_MAX_AG_BYTES (1ULL << 40) /* 1 TB */ +#define XFS_MAX_AG_BLOCKS (XFS_MAX_AG_BYTES / XFS_MIN_BLOCKSIZE) +#define XFS_MAX_CRC_AG_BLOCKS (XFS_MAX_AG_BYTES / XFS_MIN_CRC_BLOCKSIZE) /* keep the maximum size under 2^31 by a small amount */ #define XFS_MAX_LOG_BYTES \ diff --git a/fs/xfs/libxfs/xfs_ialloc.c b/fs/xfs/libxfs/xfs_ialloc.c index 994ad783d407f..f78a600ca73ff 100644 --- a/fs/xfs/libxfs/xfs_ialloc.c +++ b/fs/xfs/libxfs/xfs_ialloc.c @@ -2793,6 +2793,7 @@ xfs_ialloc_setup_geometry( inodes = (1LL << XFS_INO_AGINO_BITS(mp)) >> XFS_INODES_PER_CHUNK_LOG; igeo->inobt_maxlevels = xfs_btree_compute_maxlevels(igeo->inobt_mnr, inodes); + ASSERT(igeo->inobt_maxlevels <= xfs_iallocbt_maxlevels_ondisk()); /* * Set the maximum inode count for this filesystem, being careful not diff --git a/fs/xfs/libxfs/xfs_ialloc_btree.c b/fs/xfs/libxfs/xfs_ialloc_btree.c index 3a5a24648b873..74681e8811647 100644 --- a/fs/xfs/libxfs/xfs_ialloc_btree.c +++ b/fs/xfs/libxfs/xfs_ialloc_btree.c @@ -526,6 +526,17 @@ xfs_inobt_commit_staged_btree( } } +/* Calculate number of records in an inode btree block. */ +static inline unsigned int +xfs_inobt_block_maxrecs( + unsigned int blocklen, + bool leaf) +{ + if (leaf) + return blocklen / sizeof(xfs_inobt_rec_t); + return blocklen / (sizeof(xfs_inobt_key_t) + sizeof(xfs_inobt_ptr_t)); +} + /* * Calculate number of records in an inobt btree block. */ @@ -536,10 +547,54 @@ xfs_inobt_maxrecs( int leaf) { blocklen -= XFS_INOBT_BLOCK_LEN(mp); + return xfs_inobt_block_maxrecs(blocklen, leaf); +} - if (leaf) - return blocklen / sizeof(xfs_inobt_rec_t); - return blocklen / (sizeof(xfs_inobt_key_t) + sizeof(xfs_inobt_ptr_t)); +/* + * Maximum number of inode btree records per AG. Pretend that we can fill an + * entire AG completely full of inodes except for the AG headers. + */ +#define XFS_MAX_INODE_RECORDS \ + ((XFS_MAX_AG_BYTES - (4 * BBSIZE)) / XFS_DINODE_MIN_SIZE) / \ + XFS_INODES_PER_CHUNK + +/* Compute the max possible height for the inode btree. */ +static inline unsigned int +xfs_inobt_maxlevels_ondisk(void) +{ + unsigned int minrecs[2]; + unsigned int blocklen; + + blocklen = min(XFS_MIN_BLOCKSIZE - XFS_BTREE_SBLOCK_LEN, + XFS_MIN_CRC_BLOCKSIZE - XFS_BTREE_SBLOCK_CRC_LEN); + + minrecs[0] = xfs_inobt_block_maxrecs(blocklen, true) / 2; + minrecs[1] = xfs_inobt_block_maxrecs(blocklen, false) / 2; + + return xfs_btree_compute_maxlevels(minrecs, XFS_MAX_INODE_RECORDS); +} + +/* Compute the max possible height for the free inode btree. */ +static inline unsigned int +xfs_finobt_maxlevels_ondisk(void) +{ + unsigned int minrecs[2]; + unsigned int blocklen; + + blocklen = XFS_MIN_CRC_BLOCKSIZE - XFS_BTREE_SBLOCK_CRC_LEN; + + minrecs[0] = xfs_inobt_block_maxrecs(blocklen, true) / 2; + minrecs[1] = xfs_inobt_block_maxrecs(blocklen, false) / 2; + + return xfs_btree_compute_maxlevels(minrecs, XFS_MAX_INODE_RECORDS); +} + +/* Compute the max possible height for either inode btree. */ +unsigned int +xfs_iallocbt_maxlevels_ondisk(void) +{ + return max(xfs_inobt_maxlevels_ondisk(), + xfs_finobt_maxlevels_ondisk()); } /* diff --git a/fs/xfs/libxfs/xfs_ialloc_btree.h b/fs/xfs/libxfs/xfs_ialloc_btree.h index 8a322d402e614..6d3e4a3316d75 100644 --- a/fs/xfs/libxfs/xfs_ialloc_btree.h +++ b/fs/xfs/libxfs/xfs_ialloc_btree.h @@ -75,4 +75,6 @@ int xfs_inobt_cur(struct xfs_mount *mp, struct xfs_trans *tp, void xfs_inobt_commit_staged_btree(struct xfs_btree_cur *cur, struct xfs_trans *tp, struct xfs_buf *agbp); +unsigned int xfs_iallocbt_maxlevels_ondisk(void); + #endif /* __XFS_IALLOC_BTREE_H__ */ diff --git a/fs/xfs/libxfs/xfs_refcount_btree.c b/fs/xfs/libxfs/xfs_refcount_btree.c index 995b0d86ddc05..3bf802fc33bbc 100644 --- a/fs/xfs/libxfs/xfs_refcount_btree.c +++ b/fs/xfs/libxfs/xfs_refcount_btree.c @@ -393,6 +393,18 @@ xfs_refcountbt_commit_staged_btree( xfs_btree_commit_afakeroot(cur, tp, agbp, &xfs_refcountbt_ops); } +/* Calculate number of records in a refcount btree block. */ +static inline unsigned int +xfs_refcountbt_block_maxrecs( + unsigned int blocklen, + bool leaf) +{ + if (leaf) + return blocklen / sizeof(struct xfs_refcount_rec); + return blocklen / (sizeof(struct xfs_refcount_key) + + sizeof(xfs_refcount_ptr_t)); +} + /* * Calculate the number of records in a refcount btree block. */ @@ -402,11 +414,22 @@ xfs_refcountbt_maxrecs( bool leaf) { blocklen -= XFS_REFCOUNT_BLOCK_LEN; + return xfs_refcountbt_block_maxrecs(blocklen, leaf); +} - if (leaf) - return blocklen / sizeof(struct xfs_refcount_rec); - return blocklen / (sizeof(struct xfs_refcount_key) + - sizeof(xfs_refcount_ptr_t)); +/* Compute the max possible height of the maximally sized refcount btree. */ +unsigned int +xfs_refcountbt_maxlevels_ondisk(void) +{ + unsigned int minrecs[2]; + unsigned int blocklen; + + blocklen = XFS_MIN_CRC_BLOCKSIZE - XFS_BTREE_SBLOCK_CRC_LEN; + + minrecs[0] = xfs_refcountbt_block_maxrecs(blocklen, true) / 2; + minrecs[1] = xfs_refcountbt_block_maxrecs(blocklen, false) / 2; + + return xfs_btree_compute_maxlevels(minrecs, XFS_MAX_CRC_AG_BLOCKS); } /* Compute the maximum height of a refcount btree. */ @@ -414,8 +437,14 @@ void xfs_refcountbt_compute_maxlevels( struct xfs_mount *mp) { + if (!xfs_has_reflink(mp)) { + mp->m_refc_maxlevels = 0; + return; + } + mp->m_refc_maxlevels = xfs_btree_compute_maxlevels( mp->m_refc_mnr, mp->m_sb.sb_agblocks); + ASSERT(mp->m_refc_maxlevels <= xfs_refcountbt_maxlevels_ondisk()); } /* Calculate the refcount btree size for some records. */ diff --git a/fs/xfs/libxfs/xfs_refcount_btree.h b/fs/xfs/libxfs/xfs_refcount_btree.h index bd9ed9e1e41ff..d7f7c89cbf355 100644 --- a/fs/xfs/libxfs/xfs_refcount_btree.h +++ b/fs/xfs/libxfs/xfs_refcount_btree.h @@ -65,4 +65,6 @@ extern int xfs_refcountbt_calc_reserves(struct xfs_mount *mp, void xfs_refcountbt_commit_staged_btree(struct xfs_btree_cur *cur, struct xfs_trans *tp, struct xfs_buf *agbp); +unsigned int xfs_refcountbt_maxlevels_ondisk(void); + #endif /* __XFS_REFCOUNT_BTREE_H__ */ diff --git a/fs/xfs/libxfs/xfs_rmap_btree.c b/fs/xfs/libxfs/xfs_rmap_btree.c index 7388201e48d27..0c96e26daca96 100644 --- a/fs/xfs/libxfs/xfs_rmap_btree.c +++ b/fs/xfs/libxfs/xfs_rmap_btree.c @@ -519,6 +519,18 @@ xfs_rmapbt_commit_staged_btree( xfs_btree_commit_afakeroot(cur, tp, agbp, &xfs_rmapbt_ops); } +/* Calculate number of records in a reverse mapping btree block. */ +static inline unsigned int +xfs_rmapbt_block_maxrecs( + unsigned int blocklen, + bool leaf) +{ + if (leaf) + return blocklen / sizeof(struct xfs_rmap_rec); + return blocklen / + (2 * sizeof(struct xfs_rmap_key) + sizeof(xfs_rmap_ptr_t)); +} + /* * Calculate number of records in an rmap btree block. */ @@ -528,11 +540,33 @@ xfs_rmapbt_maxrecs( int leaf) { blocklen -= XFS_RMAP_BLOCK_LEN; + return xfs_rmapbt_block_maxrecs(blocklen, leaf); +} - if (leaf) - return blocklen / sizeof(struct xfs_rmap_rec); - return blocklen / - (2 * sizeof(struct xfs_rmap_key) + sizeof(xfs_rmap_ptr_t)); +/* Compute the max possible height for reverse mapping btrees. */ +unsigned int +xfs_rmapbt_maxlevels_ondisk(void) +{ + unsigned int minrecs[2]; + unsigned int blocklen; + + blocklen = XFS_MIN_CRC_BLOCKSIZE - XFS_BTREE_SBLOCK_CRC_LEN; + + minrecs[0] = xfs_rmapbt_block_maxrecs(blocklen, true) / 2; + minrecs[1] = xfs_rmapbt_block_maxrecs(blocklen, false) / 2; + + /* + * Compute the asymptotic maxlevels for an rmapbt on any reflink fs. + * + * On a reflink filesystem, each AG block can have up to 2^32 (per the + * refcount record format) owners, which means that theoretically we + * could face up to 2^64 rmap records. However, we're likely to run + * out of blocks in the AG long before that happens, which means that + * we must compute the max height based on what the btree will look + * like if it consumes almost all the blocks in the AG due to maximal + * sharing factor. + */ + return xfs_btree_space_to_height(minrecs, XFS_MAX_CRC_AG_BLOCKS); } /* Compute the maximum height of an rmap btree. */ @@ -569,6 +603,7 @@ xfs_rmapbt_compute_maxlevels( mp->m_rmap_maxlevels = xfs_btree_compute_maxlevels( mp->m_rmap_mnr, mp->m_sb.sb_agblocks); } + ASSERT(mp->m_rmap_maxlevels <= xfs_rmapbt_maxlevels_ondisk()); } /* Calculate the refcount btree size for some records. */ diff --git a/fs/xfs/libxfs/xfs_rmap_btree.h b/fs/xfs/libxfs/xfs_rmap_btree.h index f2eee6572af4a..e9778b62ad55b 100644 --- a/fs/xfs/libxfs/xfs_rmap_btree.h +++ b/fs/xfs/libxfs/xfs_rmap_btree.h @@ -59,4 +59,6 @@ extern xfs_extlen_t xfs_rmapbt_max_size(struct xfs_mount *mp, extern int xfs_rmapbt_calc_reserves(struct xfs_mount *mp, struct xfs_trans *tp, struct xfs_perag *pag, xfs_extlen_t *ask, xfs_extlen_t *used); +unsigned int xfs_rmapbt_maxlevels_ondisk(void); + #endif /* __XFS_RMAP_BTREE_H__ */