| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Christoph Hellwig | 14251 | 67.94% | 49 | 23.79% |
| Darrick J. Wong | 4587 | 21.87% | 72 | 34.95% |
| David Chinner | 1544 | 7.36% | 46 | 22.33% |
| Brian Foster | 182 | 0.87% | 5 | 2.43% |
| Nathan Scott | 175 | 0.83% | 4 | 1.94% |
| Eric Sandeen | 156 | 0.74% | 14 | 6.80% |
| Russell Cattelan | 37 | 0.18% | 2 | 0.97% |
| Stephen Lord | 17 | 0.08% | 1 | 0.49% |
| Chandra Seetharaman | 5 | 0.02% | 1 | 0.49% |
| David Howells | 4 | 0.02% | 1 | 0.49% |
| Mandy Kirkconnell | 4 | 0.02% | 1 | 0.49% |
| Carlos Maiolino | 3 | 0.01% | 2 | 0.97% |
| Malcolm Parsons | 2 | 0.01% | 1 | 0.49% |
| Zhi Yong Wu | 2 | 0.01% | 2 | 0.97% |
| Geliang Tang | 2 | 0.01% | 1 | 0.49% |
| Eric Biggers | 2 | 0.01% | 1 | 0.49% |
| zhengbin | 1 | 0.00% | 1 | 0.49% |
| Zheng Yongjun | 1 | 0.00% | 1 | 0.49% |
| Glen Overby | 1 | 0.00% | 1 | 0.49% |
| Total | 20976 | 206 |
// SPDX-License-Identifier: GPL-2.0 /* * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc. * All Rights Reserved. */ #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_buf_item.h" #include "xfs_btree.h" #include "xfs_errortag.h" #include "xfs_error.h" #include "xfs_trace.h" #include "xfs_alloc.h" #include "xfs_log.h" #include "xfs_btree_staging.h" #include "xfs_ag.h" #include "xfs_alloc_btree.h" #include "xfs_ialloc_btree.h" #include "xfs_bmap_btree.h" #include "xfs_rmap_btree.h" #include "xfs_refcount_btree.h" /* * Btree magic numbers. */ static const uint32_t xfs_magics[2][XFS_BTNUM_MAX] = { { XFS_ABTB_MAGIC, XFS_ABTC_MAGIC, 0, XFS_BMAP_MAGIC, XFS_IBT_MAGIC, XFS_FIBT_MAGIC, 0 }, { XFS_ABTB_CRC_MAGIC, XFS_ABTC_CRC_MAGIC, XFS_RMAP_CRC_MAGIC, XFS_BMAP_CRC_MAGIC, XFS_IBT_CRC_MAGIC, XFS_FIBT_CRC_MAGIC, XFS_REFC_CRC_MAGIC } }; uint32_t xfs_btree_magic( int crc, xfs_btnum_t btnum) { uint32_t magic = xfs_magics[crc][btnum]; /* Ensure we asked for crc for crc-only magics. */ ASSERT(magic != 0); return magic; } /* * These sibling pointer checks are optimised for null sibling pointers. This * happens a lot, and we don't need to byte swap at runtime if the sibling * pointer is NULL. * * These are explicitly marked at inline because the cost of calling them as * functions instead of inlining them is about 36 bytes extra code per call site * on x86-64. Yes, gcc-11 fails to inline them, and explicit inlining of these * two sibling check functions reduces the compiled code size by over 300 * bytes. */ static inline xfs_failaddr_t xfs_btree_check_lblock_siblings( struct xfs_mount *mp, struct xfs_btree_cur *cur, int level, xfs_fsblock_t fsb, __be64 dsibling) { xfs_fsblock_t sibling; if (dsibling == cpu_to_be64(NULLFSBLOCK)) return NULL; sibling = be64_to_cpu(dsibling); if (sibling == fsb) return __this_address; if (level >= 0) { if (!xfs_btree_check_lptr(cur, sibling, level + 1)) return __this_address; } else { if (!xfs_verify_fsbno(mp, sibling)) return __this_address; } return NULL; } static inline xfs_failaddr_t xfs_btree_check_sblock_siblings( struct xfs_perag *pag, struct xfs_btree_cur *cur, int level, xfs_agblock_t agbno, __be32 dsibling) { xfs_agblock_t sibling; if (dsibling == cpu_to_be32(NULLAGBLOCK)) return NULL; sibling = be32_to_cpu(dsibling); if (sibling == agbno) return __this_address; if (level >= 0) { if (!xfs_btree_check_sptr(cur, sibling, level + 1)) return __this_address; } else { if (!xfs_verify_agbno(pag, sibling)) return __this_address; } return NULL; } /* * Check a long btree block header. Return the address of the failing check, * or NULL if everything is ok. */ xfs_failaddr_t __xfs_btree_check_lblock( struct xfs_btree_cur *cur, struct xfs_btree_block *block, int level, struct xfs_buf *bp) { struct xfs_mount *mp = cur->bc_mp; xfs_btnum_t btnum = cur->bc_btnum; int crc = xfs_has_crc(mp); xfs_failaddr_t fa; xfs_fsblock_t fsb = NULLFSBLOCK; if (crc) { if (!uuid_equal(&block->bb_u.l.bb_uuid, &mp->m_sb.sb_meta_uuid)) return __this_address; if (block->bb_u.l.bb_blkno != cpu_to_be64(bp ? xfs_buf_daddr(bp) : XFS_BUF_DADDR_NULL)) return __this_address; if (block->bb_u.l.bb_pad != cpu_to_be32(0)) return __this_address; } if (be32_to_cpu(block->bb_magic) != xfs_btree_magic(crc, btnum)) return __this_address; if (be16_to_cpu(block->bb_level) != level) return __this_address; if (be16_to_cpu(block->bb_numrecs) > cur->bc_ops->get_maxrecs(cur, level)) return __this_address; if (bp) fsb = XFS_DADDR_TO_FSB(mp, xfs_buf_daddr(bp)); fa = xfs_btree_check_lblock_siblings(mp, cur, level, fsb, block->bb_u.l.bb_leftsib); if (!fa) fa = xfs_btree_check_lblock_siblings(mp, cur, level, fsb, block->bb_u.l.bb_rightsib); return fa; } /* Check a long btree block header. */ static int xfs_btree_check_lblock( struct xfs_btree_cur *cur, struct xfs_btree_block *block, int level, struct xfs_buf *bp) { struct xfs_mount *mp = cur->bc_mp; xfs_failaddr_t fa; fa = __xfs_btree_check_lblock(cur, block, level, bp); if (XFS_IS_CORRUPT(mp, fa != NULL) || XFS_TEST_ERROR(false, mp, XFS_ERRTAG_BTREE_CHECK_LBLOCK)) { if (bp) trace_xfs_btree_corrupt(bp, _RET_IP_); return -EFSCORRUPTED; } return 0; } /* * Check a short btree block header. Return the address of the failing check, * or NULL if everything is ok. */ xfs_failaddr_t __xfs_btree_check_sblock( struct xfs_btree_cur *cur, struct xfs_btree_block *block, int level, struct xfs_buf *bp) { struct xfs_mount *mp = cur->bc_mp; struct xfs_perag *pag = cur->bc_ag.pag; xfs_btnum_t btnum = cur->bc_btnum; int crc = xfs_has_crc(mp); xfs_failaddr_t fa; xfs_agblock_t agbno = NULLAGBLOCK; if (crc) { if (!uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid)) return __this_address; if (block->bb_u.s.bb_blkno != cpu_to_be64(bp ? xfs_buf_daddr(bp) : XFS_BUF_DADDR_NULL)) return __this_address; } if (be32_to_cpu(block->bb_magic) != xfs_btree_magic(crc, btnum)) return __this_address; if (be16_to_cpu(block->bb_level) != level) return __this_address; if (be16_to_cpu(block->bb_numrecs) > cur->bc_ops->get_maxrecs(cur, level)) return __this_address; if (bp) agbno = xfs_daddr_to_agbno(mp, xfs_buf_daddr(bp)); fa = xfs_btree_check_sblock_siblings(pag, cur, level, agbno, block->bb_u.s.bb_leftsib); if (!fa) fa = xfs_btree_check_sblock_siblings(pag, cur, level, agbno, block->bb_u.s.bb_rightsib); return fa; } /* Check a short btree block header. */ STATIC int xfs_btree_check_sblock( struct xfs_btree_cur *cur, struct xfs_btree_block *block, int level, struct xfs_buf *bp) { struct xfs_mount *mp = cur->bc_mp; xfs_failaddr_t fa; fa = __xfs_btree_check_sblock(cur, block, level, bp); if (XFS_IS_CORRUPT(mp, fa != NULL) || XFS_TEST_ERROR(false, mp, XFS_ERRTAG_BTREE_CHECK_SBLOCK)) { if (bp) trace_xfs_btree_corrupt(bp, _RET_IP_); return -EFSCORRUPTED; } return 0; } /* * Debug routine: check that block header is ok. */ int xfs_btree_check_block( struct xfs_btree_cur *cur, /* btree cursor */ struct xfs_btree_block *block, /* generic btree block pointer */ int level, /* level of the btree block */ struct xfs_buf *bp) /* buffer containing block, if any */ { if (cur->bc_flags & XFS_BTREE_LONG_PTRS) return xfs_btree_check_lblock(cur, block, level, bp); else return xfs_btree_check_sblock(cur, block, level, bp); } /* Check that this long pointer is valid and points within the fs. */ bool xfs_btree_check_lptr( struct xfs_btree_cur *cur, xfs_fsblock_t fsbno, int level) { if (level <= 0) return false; return xfs_verify_fsbno(cur->bc_mp, fsbno); } /* Check that this short pointer is valid and points within the AG. */ bool xfs_btree_check_sptr( struct xfs_btree_cur *cur, xfs_agblock_t agbno, int level) { if (level <= 0) return false; return xfs_verify_agbno(cur->bc_ag.pag, agbno); } /* * Check that a given (indexed) btree pointer at a certain level of a * btree is valid and doesn't point past where it should. */ static int xfs_btree_check_ptr( struct xfs_btree_cur *cur, const union xfs_btree_ptr *ptr, int index, int level) { if (cur->bc_flags & XFS_BTREE_LONG_PTRS) { if (xfs_btree_check_lptr(cur, be64_to_cpu((&ptr->l)[index]), level)) return 0; xfs_err(cur->bc_mp, "Inode %llu fork %d: Corrupt btree %d pointer at level %d index %d.", cur->bc_ino.ip->i_ino, cur->bc_ino.whichfork, cur->bc_btnum, level, index); } else { if (xfs_btree_check_sptr(cur, be32_to_cpu((&ptr->s)[index]), level)) return 0; xfs_err(cur->bc_mp, "AG %u: Corrupt btree %d pointer at level %d index %d.", cur->bc_ag.pag->pag_agno, cur->bc_btnum, level, index); } return -EFSCORRUPTED; } #ifdef DEBUG # define xfs_btree_debug_check_ptr xfs_btree_check_ptr #else # define xfs_btree_debug_check_ptr(...) (0) #endif /* * Calculate CRC on the whole btree block and stuff it into the * long-form btree header. * * Prior to calculting the CRC, pull the LSN out of the buffer log item and put * it into the buffer so recovery knows what the last modification was that made * it to disk. */ void xfs_btree_lblock_calc_crc( struct xfs_buf *bp) { struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp); struct xfs_buf_log_item *bip = bp->b_log_item; if (!xfs_has_crc(bp->b_mount)) return; if (bip) block->bb_u.l.bb_lsn = cpu_to_be64(bip->bli_item.li_lsn); xfs_buf_update_cksum(bp, XFS_BTREE_LBLOCK_CRC_OFF); } bool xfs_btree_lblock_verify_crc( struct xfs_buf *bp) { struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp); struct xfs_mount *mp = bp->b_mount; if (xfs_has_crc(mp)) { if (!xfs_log_check_lsn(mp, be64_to_cpu(block->bb_u.l.bb_lsn))) return false; return xfs_buf_verify_cksum(bp, XFS_BTREE_LBLOCK_CRC_OFF); } return true; } /* * Calculate CRC on the whole btree block and stuff it into the * short-form btree header. * * Prior to calculting the CRC, pull the LSN out of the buffer log item and put * it into the buffer so recovery knows what the last modification was that made * it to disk. */ void xfs_btree_sblock_calc_crc( struct xfs_buf *bp) { struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp); struct xfs_buf_log_item *bip = bp->b_log_item; if (!xfs_has_crc(bp->b_mount)) return; if (bip) block->bb_u.s.bb_lsn = cpu_to_be64(bip->bli_item.li_lsn); xfs_buf_update_cksum(bp, XFS_BTREE_SBLOCK_CRC_OFF); } bool xfs_btree_sblock_verify_crc( struct xfs_buf *bp) { struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp); struct xfs_mount *mp = bp->b_mount; if (xfs_has_crc(mp)) { if (!xfs_log_check_lsn(mp, be64_to_cpu(block->bb_u.s.bb_lsn))) return false; return xfs_buf_verify_cksum(bp, XFS_BTREE_SBLOCK_CRC_OFF); } return true; } static int xfs_btree_free_block( struct xfs_btree_cur *cur, struct xfs_buf *bp) { int error; error = cur->bc_ops->free_block(cur, bp); if (!error) { xfs_trans_binval(cur->bc_tp, bp); XFS_BTREE_STATS_INC(cur, free); } return error; } /* * Delete the btree cursor. */ void xfs_btree_del_cursor( struct xfs_btree_cur *cur, /* btree cursor */ int error) /* del because of error */ { int i; /* btree level */ /* * Clear the buffer pointers and release the buffers. If we're doing * this because of an error, inspect all of the entries in the bc_bufs * array for buffers to be unlocked. This is because some of the btree * code works from level n down to 0, and if we get an error along the * way we won't have initialized all the entries down to 0. */ for (i = 0; i < cur->bc_nlevels; i++) { if (cur->bc_levels[i].bp) xfs_trans_brelse(cur->bc_tp, cur->bc_levels[i].bp); else if (!error) break; } /* * If we are doing a BMBT update, the number of unaccounted blocks * allocated during this cursor life time should be zero. If it's not * zero, then we should be shut down or on our way to shutdown due to * cancelling a dirty transaction on error. */ ASSERT(cur->bc_btnum != XFS_BTNUM_BMAP || cur->bc_ino.allocated == 0 || xfs_is_shutdown(cur->bc_mp) || error != 0); if (unlikely(cur->bc_flags & XFS_BTREE_STAGING)) kmem_free(cur->bc_ops); if (!(cur->bc_flags & XFS_BTREE_LONG_PTRS) && cur->bc_ag.pag) xfs_perag_put(cur->bc_ag.pag); kmem_cache_free(cur->bc_cache, cur); } /* * Duplicate the btree cursor. * Allocate a new one, copy the record, re-get the buffers. */ int /* error */ xfs_btree_dup_cursor( struct xfs_btree_cur *cur, /* input cursor */ struct xfs_btree_cur **ncur) /* output cursor */ { struct xfs_buf *bp; /* btree block's buffer pointer */ int error; /* error return value */ int i; /* level number of btree block */ xfs_mount_t *mp; /* mount structure for filesystem */ struct xfs_btree_cur *new; /* new cursor value */ xfs_trans_t *tp; /* transaction pointer, can be NULL */ tp = cur->bc_tp; mp = cur->bc_mp; /* * Allocate a new cursor like the old one. */ new = cur->bc_ops->dup_cursor(cur); /* * Copy the record currently in the cursor. */ new->bc_rec = cur->bc_rec; /* * For each level current, re-get the buffer and copy the ptr value. */ for (i = 0; i < new->bc_nlevels; i++) { new->bc_levels[i].ptr = cur->bc_levels[i].ptr; new->bc_levels[i].ra = cur->bc_levels[i].ra; bp = cur->bc_levels[i].bp; if (bp) { error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, xfs_buf_daddr(bp), mp->m_bsize, 0, &bp, cur->bc_ops->buf_ops); if (error) { xfs_btree_del_cursor(new, error); *ncur = NULL; return error; } } new->bc_levels[i].bp = bp; } *ncur = new; return 0; } /* * XFS btree block layout and addressing: * * There are two types of blocks in the btree: leaf and non-leaf blocks. * * The leaf record start with a header then followed by records containing * the values. A non-leaf block also starts with the same header, and * then first contains lookup keys followed by an equal number of pointers * to the btree blocks at the previous level. * * +--------+-------+-------+-------+-------+-------+-------+ * Leaf: | header | rec 1 | rec 2 | rec 3 | rec 4 | rec 5 | rec N | * +--------+-------+-------+-------+-------+-------+-------+ * * +--------+-------+-------+-------+-------+-------+-------+ * Non-Leaf: | header | key 1 | key 2 | key N | ptr 1 | ptr 2 | ptr N | * +--------+-------+-------+-------+-------+-------+-------+ * * The header is called struct xfs_btree_block for reasons better left unknown * and comes in different versions for short (32bit) and long (64bit) block * pointers. The record and key structures are defined by the btree instances * and opaque to the btree core. The block pointers are simple disk endian * integers, available in a short (32bit) and long (64bit) variant. * * The helpers below calculate the offset of a given record, key or pointer * into a btree block (xfs_btree_*_offset) or return a pointer to the given * record, key or pointer (xfs_btree_*_addr). Note that all addressing * inside the btree block is done using indices starting at one, not zero! * * If XFS_BTREE_OVERLAPPING is set, then this btree supports keys containing * overlapping intervals. In such a tree, records are still sorted lowest to * highest and indexed by the smallest key value that refers to the record. * However, nodes are different: each pointer has two associated keys -- one * indexing the lowest key available in the block(s) below (the same behavior * as the key in a regular btree) and another indexing the highest key * available in the block(s) below. Because records are /not/ sorted by the * highest key, all leaf block updates require us to compute the highest key * that matches any record in the leaf and to recursively update the high keys * in the nodes going further up in the tree, if necessary. Nodes look like * this: * * +--------+-----+-----+-----+-----+-----+-------+-------+-----+ * Non-Leaf: | header | lo1 | hi1 | lo2 | hi2 | ... | ptr 1 | ptr 2 | ... | * +--------+-----+-----+-----+-----+-----+-------+-------+-----+ * * To perform an interval query on an overlapped tree, perform the usual * depth-first search and use the low and high keys to decide if we can skip * that particular node. If a leaf node is reached, return the records that * intersect the interval. Note that an interval query may return numerous * entries. For a non-overlapped tree, simply search for the record associated * with the lowest key and iterate forward until a non-matching record is * found. Section 14.3 ("Interval Trees") of _Introduction to Algorithms_ by * Cormen, Leiserson, Rivest, and Stein (2nd or 3rd ed. only) discuss this in * more detail. * * Why do we care about overlapping intervals? Let's say you have a bunch of * reverse mapping records on a reflink filesystem: * * 1: +- file A startblock B offset C length D -----------+ * 2: +- file E startblock F offset G length H --------------+ * 3: +- file I startblock F offset J length K --+ * 4: +- file L... --+ * * Now say we want to map block (B+D) into file A at offset (C+D). Ideally, * we'd simply increment the length of record 1. But how do we find the record * that ends at (B+D-1) (i.e. record 1)? A LE lookup of (B+D-1) would return * record 3 because the keys are ordered first by startblock. An interval * query would return records 1 and 2 because they both overlap (B+D-1), and * from that we can pick out record 1 as the appropriate left neighbor. * * In the non-overlapped case you can do a LE lookup and decrement the cursor * because a record's interval must end before the next record. */ /* * Return size of the btree block header for this btree instance. */ static inline size_t xfs_btree_block_len(struct xfs_btree_cur *cur) { if (cur->bc_flags & XFS_BTREE_LONG_PTRS) { if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS) return XFS_BTREE_LBLOCK_CRC_LEN; return XFS_BTREE_LBLOCK_LEN; } if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS) return XFS_BTREE_SBLOCK_CRC_LEN; return XFS_BTREE_SBLOCK_LEN; } /* * Return size of btree block pointers for this btree instance. */ static inline size_t xfs_btree_ptr_len(struct xfs_btree_cur *cur) { return (cur->bc_flags & XFS_BTREE_LONG_PTRS) ? sizeof(__be64) : sizeof(__be32); } /* * Calculate offset of the n-th record in a btree block. */ STATIC size_t xfs_btree_rec_offset( struct xfs_btree_cur *cur, int n) { return xfs_btree_block_len(cur) + (n - 1) * cur->bc_ops->rec_len; } /* * Calculate offset of the n-th key in a btree block. */ STATIC size_t xfs_btree_key_offset( struct xfs_btree_cur *cur, int n) { return xfs_btree_block_len(cur) + (n - 1) * cur->bc_ops->key_len; } /* * Calculate offset of the n-th high key in a btree block. */ STATIC size_t xfs_btree_high_key_offset( struct xfs_btree_cur *cur, int n) { return xfs_btree_block_len(cur) + (n - 1) * cur->bc_ops->key_len + (cur->bc_ops->key_len / 2); } /* * Calculate offset of the n-th block pointer in a btree block. */ STATIC size_t xfs_btree_ptr_offset( struct xfs_btree_cur *cur, int n, int level) { return xfs_btree_block_len(cur) + cur->bc_ops->get_maxrecs(cur, level) * cur->bc_ops->key_len + (n - 1) * xfs_btree_ptr_len(cur); } /* * Return a pointer to the n-th record in the btree block. */ union xfs_btree_rec * xfs_btree_rec_addr( struct xfs_btree_cur *cur, int n, struct xfs_btree_block *block) { return (union xfs_btree_rec *) ((char *)block + xfs_btree_rec_offset(cur, n)); } /* * Return a pointer to the n-th key in the btree block. */ union xfs_btree_key * xfs_btree_key_addr( struct xfs_btree_cur *cur, int n, struct xfs_btree_block *block) { return (union xfs_btree_key *) ((char *)block + xfs_btree_key_offset(cur, n)); } /* * Return a pointer to the n-th high key in the btree block. */ union xfs_btree_key * xfs_btree_high_key_addr( struct xfs_btree_cur *cur, int n, struct xfs_btree_block *block) { return (union xfs_btree_key *) ((char *)block + xfs_btree_high_key_offset(cur, n)); } /* * Return a pointer to the n-th block pointer in the btree block. */ union xfs_btree_ptr * xfs_btree_ptr_addr( struct xfs_btree_cur *cur, int n, struct xfs_btree_block *block) { int level = xfs_btree_get_level(block); ASSERT(block->bb_level != 0); return (union xfs_btree_ptr *) ((char *)block + xfs_btree_ptr_offset(cur, n, level)); } struct xfs_ifork * xfs_btree_ifork_ptr( struct xfs_btree_cur *cur) { ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE); if (cur->bc_flags & XFS_BTREE_STAGING) return cur->bc_ino.ifake->if_fork; return xfs_ifork_ptr(cur->bc_ino.ip, cur->bc_ino.whichfork); } /* * Get the root block which is stored in the inode. * * For now this btree implementation assumes the btree root is always * stored in the if_broot field of an inode fork. */ STATIC struct xfs_btree_block * xfs_btree_get_iroot( struct xfs_btree_cur *cur) { struct xfs_ifork *ifp = xfs_btree_ifork_ptr(cur); return (struct xfs_btree_block *)ifp->if_broot; } /* * Retrieve the block pointer from the cursor at the given level. * This may be an inode btree root or from a buffer. */ struct xfs_btree_block * /* generic btree block pointer */ xfs_btree_get_block( struct xfs_btree_cur *cur, /* btree cursor */ int level, /* level in btree */ struct xfs_buf **bpp) /* buffer containing the block */ { if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) && (level == cur->bc_nlevels - 1)) { *bpp = NULL; return xfs_btree_get_iroot(cur); } *bpp = cur->bc_levels[level].bp; return XFS_BUF_TO_BLOCK(*bpp); } /* * Change the cursor to point to the first record at the given level. * Other levels are unaffected. */ STATIC int /* success=1, failure=0 */ xfs_btree_firstrec( struct xfs_btree_cur *cur, /* btree cursor */ int level) /* level to change */ { struct xfs_btree_block *block; /* generic btree block pointer */ struct xfs_buf *bp; /* buffer containing block */ /* * Get the block pointer for this level. */ block = xfs_btree_get_block(cur, level, &bp); if (xfs_btree_check_block(cur, block, level, bp)) return 0; /* * It's empty, there is no such record. */ if (!block->bb_numrecs) return 0; /* * Set the ptr value to 1, that's the first record/key. */ cur->bc_levels[level].ptr = 1; return 1; } /* * Change the cursor to point to the last record in the current block * at the given level. Other levels are unaffected. */ STATIC int /* success=1, failure=0 */ xfs_btree_lastrec( struct xfs_btree_cur *cur, /* btree cursor */ int level) /* level to change */ { struct xfs_btree_block *block; /* generic btree block pointer */ struct xfs_buf *bp; /* buffer containing block */ /* * Get the block pointer for this level. */ block = xfs_btree_get_block(cur, level, &bp); if (xfs_btree_check_block(cur, block, level, bp)) return 0; /* * It's empty, there is no such record. */ if (!block->bb_numrecs) return 0; /* * Set the ptr value to numrecs, that's the last record/key. */ cur->bc_levels[level].ptr = be16_to_cpu(block->bb_numrecs); return 1; } /* * Compute first and last byte offsets for the fields given. * Interprets the offsets table, which contains struct field offsets. */ void xfs_btree_offsets( uint32_t fields, /* bitmask of fields */ const short *offsets, /* table of field offsets */ int nbits, /* number of bits to inspect */ int *first, /* output: first byte offset */ int *last) /* output: last byte offset */ { int i; /* current bit number */ uint32_t imask; /* mask for current bit number */ ASSERT(fields != 0); /* * Find the lowest bit, so the first byte offset. */ for (i = 0, imask = 1u; ; i++, imask <<= 1) { if (imask & fields) { *first = offsets[i]; break; } } /* * Find the highest bit, so the last byte offset. */ for (i = nbits - 1, imask = 1u << i; ; i--, imask >>= 1) { if (imask & fields) { *last = offsets[i + 1] - 1; break; } } } /* * Get a buffer for the block, return it read in. * Long-form addressing. */ int xfs_btree_read_bufl( struct xfs_mount *mp, /* file system mount point */ struct xfs_trans *tp, /* transaction pointer */ xfs_fsblock_t fsbno, /* file system block number */ struct xfs_buf **bpp, /* buffer for fsbno */ int refval, /* ref count value for buffer */ const struct xfs_buf_ops *ops) { struct xfs_buf *bp; /* return value */ xfs_daddr_t d; /* real disk block address */ int error; if (!xfs_verify_fsbno(mp, fsbno)) return -EFSCORRUPTED; d = XFS_FSB_TO_DADDR(mp, fsbno); error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, d, mp->m_bsize, 0, &bp, ops); if (error) return error; if (bp) xfs_buf_set_ref(bp, refval); *bpp = bp; return 0; } /* * Read-ahead the block, don't wait for it, don't return a buffer. * Long-form addressing. */ /* ARGSUSED */ void xfs_btree_reada_bufl( struct xfs_mount *mp, /* file system mount point */ xfs_fsblock_t fsbno, /* file system block number */ xfs_extlen_t count, /* count of filesystem blocks */ const struct xfs_buf_ops *ops) { xfs_daddr_t d; ASSERT(fsbno != NULLFSBLOCK); d = XFS_FSB_TO_DADDR(mp, fsbno); xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count, ops); } /* * Read-ahead the block, don't wait for it, don't return a buffer. * Short-form addressing. */ /* ARGSUSED */ void xfs_btree_reada_bufs( struct xfs_mount *mp, /* file system mount point */ xfs_agnumber_t agno, /* allocation group number */ xfs_agblock_t agbno, /* allocation group block number */ xfs_extlen_t count, /* count of filesystem blocks */ const struct xfs_buf_ops *ops) { xfs_daddr_t d; ASSERT(agno != NULLAGNUMBER); ASSERT(agbno != NULLAGBLOCK); d = XFS_AGB_TO_DADDR(mp, agno, agbno); xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count, ops); } STATIC int xfs_btree_readahead_lblock( struct xfs_btree_cur *cur, int lr, struct xfs_btree_block *block) { int rval = 0; xfs_fsblock_t left = be64_to_cpu(block->bb_u.l.bb_leftsib); xfs_fsblock_t right = be64_to_cpu(block->bb_u.l.bb_rightsib); if ((lr & XFS_BTCUR_LEFTRA) && left != NULLFSBLOCK) { xfs_btree_reada_bufl(cur->bc_mp, left, 1, cur->bc_ops->buf_ops); rval++; } if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLFSBLOCK) { xfs_btree_reada_bufl(cur->bc_mp, right, 1, cur->bc_ops->buf_ops); rval++; } return rval; } STATIC int xfs_btree_readahead_sblock( struct xfs_btree_cur *cur, int lr, struct xfs_btree_block *block) { int rval = 0; xfs_agblock_t left = be32_to_cpu(block->bb_u.s.bb_leftsib); xfs_agblock_t right = be32_to_cpu(block->bb_u.s.bb_rightsib); if ((lr & XFS_BTCUR_LEFTRA) && left != NULLAGBLOCK) { xfs_btree_reada_bufs(cur->bc_mp, cur->bc_ag.pag->pag_agno, left, 1, cur->bc_ops->buf_ops); rval++; } if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLAGBLOCK) { xfs_btree_reada_bufs(cur->bc_mp, cur->bc_ag.pag->pag_agno, right, 1, cur->bc_ops->buf_ops); rval++; } return rval; } /* * Read-ahead btree blocks, at the given level. * Bits in lr are set from XFS_BTCUR_{LEFT,RIGHT}RA. */ STATIC int xfs_btree_readahead( struct xfs_btree_cur *cur, /* btree cursor */ int lev, /* level in btree */ int lr) /* left/right bits */ { struct xfs_btree_block *block; /* * No readahead needed if we are at the root level and the * btree root is stored in the inode. */ if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) && (lev == cur->bc_nlevels - 1)) return 0; if ((cur->bc_levels[lev].ra | lr) == cur->bc_levels[lev].ra) return 0; cur->bc_levels[lev].ra |= lr; block = XFS_BUF_TO_BLOCK(cur->bc_levels[lev].bp); if (cur->bc_flags & XFS_BTREE_LONG_PTRS) return xfs_btree_readahead_lblock(cur, lr, block); return xfs_btree_readahead_sblock(cur, lr, block); } STATIC int xfs_btree_ptr_to_daddr( struct xfs_btree_cur *cur, const union xfs_btree_ptr *ptr, xfs_daddr_t *daddr) { xfs_fsblock_t fsbno; xfs_agblock_t agbno; int error; error = xfs_btree_check_ptr(cur, ptr, 0, 1); if (error) return error; if (cur->bc_flags & XFS_BTREE_LONG_PTRS) { fsbno = be64_to_cpu(ptr->l); *daddr = XFS_FSB_TO_DADDR(cur->bc_mp, fsbno); } else { agbno = be32_to_cpu(ptr->s); *daddr = XFS_AGB_TO_DADDR(cur->bc_mp, cur->bc_ag.pag->pag_agno, agbno); } return 0; } /* * Readahead @count btree blocks at the given @ptr location. * * We don't need to care about long or short form btrees here as we have a * method of converting the ptr directly to a daddr available to us. */ STATIC void xfs_btree_readahead_ptr( struct xfs_btree_cur *cur, union xfs_btree_ptr *ptr, xfs_extlen_t count) { xfs_daddr_t daddr; if (xfs_btree_ptr_to_daddr(cur, ptr, &daddr)) return; xfs_buf_readahead(cur->bc_mp->m_ddev_targp, daddr, cur->bc_mp->m_bsize * count, cur->bc_ops->buf_ops); } /* * Set the buffer for level "lev" in the cursor to bp, releasing * any previous buffer. */ STATIC void xfs_btree_setbuf( struct xfs_btree_cur *cur, /* btree cursor */ int lev, /* level in btree */ struct xfs_buf *bp) /* new buffer to set */ { struct xfs_btree_block *b; /* btree block */ if (cur->bc_levels[lev].bp) xfs_trans_brelse(cur->bc_tp, cur->bc_levels[lev].bp); cur->bc_levels[lev].bp = bp; cur->bc_levels[lev].ra = 0; b = XFS_BUF_TO_BLOCK(bp); if (cur->bc_flags & XFS_BTREE_LONG_PTRS) { if (b->bb_u.l.bb_leftsib == cpu_to_be64(NULLFSBLOCK)) cur->bc_levels[lev].ra |= XFS_BTCUR_LEFTRA; if (b->bb_u.l.bb_rightsib == cpu_to_be64(NULLFSBLOCK)) cur->bc_levels[lev].ra |= XFS_BTCUR_RIGHTRA; } else { if (b->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK)) cur->bc_levels[lev].ra |= XFS_BTCUR_LEFTRA; if (b->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK)) cur->bc_levels[lev].ra |= XFS_BTCUR_RIGHTRA; } } bool xfs_btree_ptr_is_null( struct xfs_btree_cur *cur, const union xfs_btree_ptr *ptr) { if (cur->bc_flags & XFS_BTREE_LONG_PTRS) return ptr->l == cpu_to_be64(NULLFSBLOCK); else return ptr->s == cpu_to_be32(NULLAGBLOCK); } void xfs_btree_set_ptr_null( struct xfs_btree_cur *cur, union xfs_btree_ptr *ptr) { if (cur->bc_flags & XFS_BTREE_LONG_PTRS) ptr->l = cpu_to_be64(NULLFSBLOCK); else ptr->s = cpu_to_be32(NULLAGBLOCK); } /* * Get/set/init sibling pointers */ void xfs_btree_get_sibling( struct xfs_btree_cur *cur, struct xfs_btree_block *block, union xfs_btree_ptr *ptr, int lr) { ASSERT(lr == XFS_BB_LEFTSIB || lr == XFS_BB_RIGHTSIB); if (cur->bc_flags & XFS_BTREE_LONG_PTRS) { if (lr == XFS_BB_RIGHTSIB) ptr->l = block->bb_u.l.bb_rightsib; else ptr->l = block->bb_u.l.bb_leftsib; } else { if (lr == XFS_BB_RIGHTSIB) ptr->s = block->bb_u.s.bb_rightsib; else ptr->s = block->bb_u.s.bb_leftsib; } } void xfs_btree_set_sibling( struct xfs_btree_cur *cur, struct xfs_btree_block *block, const union xfs_btree_ptr *ptr, int lr) { ASSERT(lr == XFS_BB_LEFTSIB || lr == XFS_BB_RIGHTSIB); if (cur->bc_flags & XFS_BTREE_LONG_PTRS) { if (lr == XFS_BB_RIGHTSIB) block->bb_u.l.bb_rightsib = ptr->l; else block->bb_u.l.bb_leftsib = ptr->l; } else { if (lr == XFS_BB_RIGHTSIB) block->bb_u.s.bb_rightsib = ptr->s; else block->bb_u.s.bb_leftsib = ptr->s; } } void xfs_btree_init_block_int( struct xfs_mount *mp, struct xfs_btree_block *buf, xfs_daddr_t blkno, xfs_btnum_t btnum, __u16 level, __u16 numrecs, __u64 owner, unsigned int flags) { int crc = xfs_has_crc(mp); __u32 magic = xfs_btree_magic(crc, btnum); buf->bb_magic = cpu_to_be32(magic); buf->bb_level = cpu_to_be16(level); buf->bb_numrecs = cpu_to_be16(numrecs); if (flags & XFS_BTREE_LONG_PTRS) { buf->bb_u.l.bb_leftsib = cpu_to_be64(NULLFSBLOCK); buf->bb_u.l.bb_rightsib = cpu_to_be64(NULLFSBLOCK); if (crc) { buf->bb_u.l.bb_blkno = cpu_to_be64(blkno); buf->bb_u.l.bb_owner = cpu_to_be64(owner); uuid_copy(&buf->bb_u.l.bb_uuid, &mp->m_sb.sb_meta_uuid); buf->bb_u.l.bb_pad = 0; buf->bb_u.l.bb_lsn = 0; } } else { /* owner is a 32 bit value on short blocks */ __u32 __owner = (__u32)owner; buf->bb_u.s.bb_leftsib = cpu_to_be32(NULLAGBLOCK); buf->bb_u.s.bb_rightsib = cpu_to_be32(NULLAGBLOCK); if (crc) { buf->bb_u.s.bb_blkno = cpu_to_be64(blkno); buf->bb_u.s.bb_owner = cpu_to_be32(__owner); uuid_copy(&buf->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid); buf->bb_u.s.bb_lsn = 0; } } } void xfs_btree_init_block( struct xfs_mount *mp, struct xfs_buf *bp, xfs_btnum_t btnum, __u16 level, __u16 numrecs, __u64 owner) { xfs_btree_init_block_int(mp, XFS_BUF_TO_BLOCK(bp), xfs_buf_daddr(bp), btnum, level, numrecs, owner, 0); } void xfs_btree_init_block_cur( struct xfs_btree_cur *cur, struct xfs_buf *bp, int level, int numrecs) { __u64 owner; /* * we can pull the owner from the cursor right now as the different * owners align directly with the pointer size of the btree. This may * change in future, but is safe for current users of the generic btree * code. */ if (cur->bc_flags & XFS_BTREE_LONG_PTRS) owner = cur->bc_ino.ip->i_ino; else owner = cur->bc_ag.pag->pag_agno; xfs_btree_init_block_int(cur->bc_mp, XFS_BUF_TO_BLOCK(bp), xfs_buf_daddr(bp), cur->bc_btnum, level, numrecs, owner, cur->bc_flags); } /* * Return true if ptr is the last record in the btree and * we need to track updates to this record. The decision * will be further refined in the update_lastrec method. */ STATIC int xfs_btree_is_lastrec( struct xfs_btree_cur *cur, struct xfs_btree_block *block, int level) { union xfs_btree_ptr ptr; if (level > 0) return 0; if (!(cur->bc_flags & XFS_BTREE_LASTREC_UPDATE)) return 0; xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB); if (!xfs_btree_ptr_is_null(cur, &ptr)) return 0; return 1; } STATIC void xfs_btree_buf_to_ptr( struct xfs_btree_cur *cur, struct xfs_buf *bp, union xfs_btree_ptr *ptr) { if (cur->bc_flags & XFS_BTREE_LONG_PTRS) ptr->l = cpu_to_be64(XFS_DADDR_TO_FSB(cur->bc_mp, xfs_buf_daddr(bp))); else { ptr->s = cpu_to_be32(xfs_daddr_to_agbno(cur->bc_mp, xfs_buf_daddr(bp))); } } STATIC void xfs_btree_set_refs( struct xfs_btree_cur *cur, struct xfs_buf *bp) { switch (cur->bc_btnum) { case XFS_BTNUM_BNO: case XFS_BTNUM_CNT: xfs_buf_set_ref(bp, XFS_ALLOC_BTREE_REF); break; case XFS_BTNUM_INO: case XFS_BTNUM_FINO: xfs_buf_set_ref(bp, XFS_INO_BTREE_REF); break; case XFS_BTNUM_BMAP: xfs_buf_set_ref(bp, XFS_BMAP_BTREE_REF); break; case XFS_BTNUM_RMAP: xfs_buf_set_ref(bp, XFS_RMAP_BTREE_REF); break; case XFS_BTNUM_REFC: xfs_buf_set_ref(bp, XFS_REFC_BTREE_REF); break; default: ASSERT(0); } } int xfs_btree_get_buf_block( struct xfs_btree_cur *cur, const union xfs_btree_ptr *ptr, struct xfs_btree_block **block, struct xfs_buf **bpp) { struct xfs_mount *mp = cur->bc_mp; xfs_daddr_t d; int error; error = xfs_btree_ptr_to_daddr(cur, ptr, &d); if (error) return error; error = xfs_trans_get_buf(cur->bc_tp, mp->m_ddev_targp, d, mp->m_bsize, 0, bpp); if (error) return error; (*bpp)->b_ops = cur->bc_ops->buf_ops; *block = XFS_BUF_TO_BLOCK(*bpp); return 0; } /* * Read in the buffer at the given ptr and return the buffer and * the block pointer within the buffer. */ STATIC int xfs_btree_read_buf_block( struct xfs_btree_cur *cur, const union xfs_btree_ptr *ptr, int flags, struct xfs_btree_block **block, struct xfs_buf **bpp) { struct xfs_mount *mp = cur->bc_mp; xfs_daddr_t d; int error; /* need to sort out how callers deal with failures first */ ASSERT(!(flags & XBF_TRYLOCK)); error = xfs_btree_ptr_to_daddr(cur, ptr, &d); if (error) return error; error = xfs_trans_read_buf(mp, cur->bc_tp, mp->m_ddev_targp, d, mp->m_bsize, flags, bpp, cur->bc_ops->buf_ops); if (error) return error; xfs_btree_set_refs(cur, *bpp); *block = XFS_BUF_TO_BLOCK(*bpp); return 0; } /* * Copy keys from one btree block to another. */ void xfs_btree_copy_keys( struct xfs_btree_cur *cur, union xfs_btree_key *dst_key, const union xfs_btree_key *src_key, int numkeys) { ASSERT(numkeys >= 0); memcpy(dst_key, src_key, numkeys * cur->bc_ops->key_len); } /* * Copy records from one btree block to another. */ STATIC void xfs_btree_copy_recs( struct xfs_btree_cur *cur, union xfs_btree_rec *dst_rec, union xfs_btree_rec *src_rec, int numrecs) { ASSERT(numrecs >= 0); memcpy(dst_rec, src_rec, numrecs * cur->bc_ops->rec_len); } /* * Copy block pointers from one btree block to another. */ void xfs_btree_copy_ptrs( struct xfs_btree_cur *cur, union xfs_btree_ptr *dst_ptr, const union xfs_btree_ptr *src_ptr, int numptrs) { ASSERT(numptrs >= 0); memcpy(dst_ptr, src_ptr, numptrs * xfs_btree_ptr_len(cur)); } /* * Shift keys one index left/right inside a single btree block. */ STATIC void xfs_btree_shift_keys( struct xfs_btree_cur *cur, union xfs_btree_key *key, int dir, int numkeys) { char *dst_key; ASSERT(numkeys >= 0); ASSERT(dir == 1 || dir == -1); dst_key = (char *)key + (dir * cur->bc_ops->key_len); memmove(dst_key, key, numkeys * cur->bc_ops->key_len); } /* * Shift records one index left/right inside a single btree block. */ STATIC void xfs_btree_shift_recs( struct xfs_btree_cur *cur, union xfs_btree_rec *rec, int dir, int numrecs) { char *dst_rec; ASSERT(numrecs >= 0); ASSERT(dir == 1 || dir == -1); dst_rec = (char *)rec + (dir * cur->bc_ops->rec_len); memmove(dst_rec, rec, numrecs * cur->bc_ops->rec_len); } /* * Shift block pointers one index left/right inside a single btree block. */ STATIC void xfs_btree_shift_ptrs( struct xfs_btree_cur *cur, union xfs_btree_ptr *ptr, int dir, int numptrs) { char *dst_ptr; ASSERT(numptrs >= 0); ASSERT(dir == 1 || dir == -1); dst_ptr = (char *)ptr + (dir * xfs_btree_ptr_len(cur)); memmove(dst_ptr, ptr, numptrs * xfs_btree_ptr_len(cur)); } /* * Log key values from the btree block. */ STATIC void xfs_btree_log_keys( struct xfs_btree_cur *cur, struct xfs_buf *bp, int first, int last) { if (bp) { xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF); xfs_trans_log_buf(cur->bc_tp, bp, xfs_btree_key_offset(cur, first), xfs_btree_key_offset(cur, last + 1) - 1); } else { xfs_trans_log_inode(cur->bc_tp, cur->bc_ino.ip, xfs_ilog_fbroot(cur->bc_ino.whichfork)); } } /* * Log record values from the btree block. */ void xfs_btree_log_recs( struct xfs_btree_cur *cur, struct xfs_buf *bp, int first, int last) { xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF); xfs_trans_log_buf(cur->bc_tp, bp, xfs_btree_rec_offset(cur, first), xfs_btree_rec_offset(cur, last + 1) - 1); } /* * Log block pointer fields from a btree block (nonleaf). */ STATIC void xfs_btree_log_ptrs( struct xfs_btree_cur *cur, /* btree cursor */ struct xfs_buf *bp, /* buffer containing btree block */ int first, /* index of first pointer to log */ int last) /* index of last pointer to log */ { if (bp) { struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp); int level = xfs_btree_get_level(block); xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF); xfs_trans_log_buf(cur->bc_tp, bp, xfs_btree_ptr_offset(cur, first, level), xfs_btree_ptr_offset(cur, last + 1, level) - 1); } else { xfs_trans_log_inode(cur->bc_tp, cur->bc_ino.ip, xfs_ilog_fbroot(cur->bc_ino.whichfork)); } } /* * Log fields from a btree block header. */ void xfs_btree_log_block( struct xfs_btree_cur *cur, /* btree cursor */ struct xfs_buf *bp, /* buffer containing btree block */ uint32_t fields) /* mask of fields: XFS_BB_... */ { int first; /* first byte offset logged */ int last; /* last byte offset logged */ static const short soffsets[] = { /* table of offsets (short) */ offsetof(struct xfs_btree_block, bb_magic), offsetof(struct xfs_btree_block, bb_level), offsetof(struct xfs_btree_block, bb_numrecs), offsetof(struct xfs_btree_block, bb_u.s.bb_leftsib), offsetof(struct xfs_btree_block, bb_u.s.bb_rightsib), offsetof(struct xfs_btree_block, bb_u.s.bb_blkno), offsetof(struct xfs_btree_block, bb_u.s.bb_lsn), offsetof(struct xfs_btree_block, bb_u.s.bb_uuid), offsetof(struct xfs_btree_block, bb_u.s.bb_owner), offsetof(struct xfs_btree_block, bb_u.s.bb_crc), XFS_BTREE_SBLOCK_CRC_LEN }; static const short loffsets[] = { /* table of offsets (long) */ offsetof(struct xfs_btree_block, bb_magic), offsetof(struct xfs_btree_block, bb_level), offsetof(struct xfs_btree_block, bb_numrecs), offsetof(struct xfs_btree_block, bb_u.l.bb_leftsib), offsetof(struct xfs_btree_block, bb_u.l.bb_rightsib), offsetof(struct xfs_btree_block, bb_u.l.bb_blkno), offsetof(struct xfs_btree_block, bb_u.l.bb_lsn), offsetof(struct xfs_btree_block, bb_u.l.bb_uuid), offsetof(struct xfs_btree_block, bb_u.l.bb_owner), offsetof(struct xfs_btree_block, bb_u.l.bb_crc), offsetof(struct xfs_btree_block, bb_u.l.bb_pad), XFS_BTREE_LBLOCK_CRC_LEN }; if (bp) { int nbits; if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS) { /* * We don't log the CRC when updating a btree * block but instead recreate it during log * recovery. As the log buffers have checksums * of their own this is safe and avoids logging a crc * update in a lot of places. */ if (fields == XFS_BB_ALL_BITS) fields = XFS_BB_ALL_BITS_CRC; nbits = XFS_BB_NUM_BITS_CRC; } else { nbits = XFS_BB_NUM_BITS; } xfs_btree_offsets(fields, (cur->bc_flags & XFS_BTREE_LONG_PTRS) ? loffsets : soffsets, nbits, &first, &last); xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF); xfs_trans_log_buf(cur->bc_tp, bp, first, last); } else { xfs_trans_log_inode(cur->bc_tp, cur->bc_ino.ip, xfs_ilog_fbroot(cur->bc_ino.whichfork)); } } /* * Increment cursor by one record at the level. * For nonzero levels the leaf-ward information is untouched. */ int /* error */ xfs_btree_increment( struct xfs_btree_cur *cur, int level, int *stat) /* success/failure */ { struct xfs_btree_block *block; union xfs_btree_ptr ptr; struct xfs_buf *bp; int error; /* error return value */ int lev; ASSERT(level < cur->bc_nlevels); /* Read-ahead to the right at this level. */ xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA); /* Get a pointer to the btree block. */ block = xfs_btree_get_block(cur, level, &bp); #ifdef DEBUG error = xfs_btree_check_block(cur, block, level, bp); if (error) goto error0; #endif /* We're done if we remain in the block after the increment. */ if (++cur->bc_levels[level].ptr <= xfs_btree_get_numrecs(block)) goto out1; /* Fail if we just went off the right edge of the tree. */ xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB); if (xfs_btree_ptr_is_null(cur, &ptr)) goto out0; XFS_BTREE_STATS_INC(cur, increment); /* * March up the tree incrementing pointers. * Stop when we don't go off the right edge of a block. */ for (lev = level + 1; lev < cur->bc_nlevels; lev++) { block = xfs_btree_get_block(cur, lev, &bp); #ifdef DEBUG error = xfs_btree_check_block(cur, block, lev, bp); if (error) goto error0; #endif if (++cur->bc_levels[lev].ptr <= xfs_btree_get_numrecs(block)) break; /* Read-ahead the right block for the next loop. */ xfs_btree_readahead(cur, lev, XFS_BTCUR_RIGHTRA); } /* * If we went off the root then we are either seriously * confused or have the tree root in an inode. */ if (lev == cur->bc_nlevels) { if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) goto out0; ASSERT(0); error = -EFSCORRUPTED; goto error0; } ASSERT(lev < cur->bc_nlevels); /* * Now walk back down the tree, fixing up the cursor's buffer * pointers and key numbers. */ for (block = xfs_btree_get_block(cur, lev, &bp); lev > level; ) { union xfs_btree_ptr *ptrp; ptrp = xfs_btree_ptr_addr(cur, cur->bc_levels[lev].ptr, block); --lev; error = xfs_btree_read_buf_block(cur, ptrp, 0, &block, &bp); if (error) goto error0; xfs_btree_setbuf(cur, lev, bp); cur->bc_levels[lev].ptr = 1; } out1: *stat = 1; return 0; out0: *stat = 0; return 0; error0: return error; } /* * Decrement cursor by one record at the level. * For nonzero levels the leaf-ward information is untouched. */ int /* error */ xfs_btree_decrement( struct xfs_btree_cur *cur, int level, int *stat) /* success/failure */ { struct xfs_btree_block *block; struct xfs_buf *bp; int error; /* error return value */ int lev; union xfs_btree_ptr ptr; ASSERT(level < cur->bc_nlevels); /* Read-ahead to the left at this level. */ xfs_btree_readahead(cur, level, XFS_BTCUR_LEFTRA); /* We're done if we remain in the block after the decrement. */ if (--cur->bc_levels[level].ptr > 0) goto out1; /* Get a pointer to the btree block. */ block = xfs_btree_get_block(cur, level, &bp); #ifdef DEBUG error = xfs_btree_check_block(cur, block, level, bp); if (error) goto error0; #endif /* Fail if we just went off the left edge of the tree. */ xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB); if (xfs_btree_ptr_is_null(cur, &ptr)) goto out0; XFS_BTREE_STATS_INC(cur, decrement); /* * March up the tree decrementing pointers. * Stop when we don't go off the left edge of a block. */ for (lev = level + 1; lev < cur->bc_nlevels; lev++) { if (--cur->bc_levels[lev].ptr > 0) break; /* Read-ahead the left block for the next loop. */ xfs_btree_readahead(cur, lev, XFS_BTCUR_LEFTRA); } /* * If we went off the root then we are seriously confused. * or the root of the tree is in an inode. */ if (lev == cur->bc_nlevels) { if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) goto out0; ASSERT(0); error = -EFSCORRUPTED; goto error0; } ASSERT(lev < cur->bc_nlevels); /* * Now walk back down the tree, fixing up the cursor's buffer * pointers and key numbers. */ for (block = xfs_btree_get_block(cur, lev, &bp); lev > level; ) { union xfs_btree_ptr *ptrp; ptrp = xfs_btree_ptr_addr(cur, cur->bc_levels[lev].ptr, block); --lev; error = xfs_btree_read_buf_block(cur, ptrp, 0, &block, &bp); if (error) goto error0; xfs_btree_setbuf(cur, lev, bp); cur->bc_levels[lev].ptr = xfs_btree_get_numrecs(block); } out1: *stat = 1; return 0; out0: *stat = 0; return 0; error0: return error; } int xfs_btree_lookup_get_block( struct xfs_btree_cur *cur, /* btree cursor */ int level, /* level in the btree */ const union xfs_btree_ptr *pp, /* ptr to btree block */ struct xfs_btree_block **blkp) /* return btree block */ { struct xfs_buf *bp; /* buffer pointer for btree block */ xfs_daddr_t daddr; int error = 0; /* special case the root block if in an inode */ if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) && (level == cur->bc_nlevels - 1)) { *blkp = xfs_btree_get_iroot(cur); return 0; } /* * If the old buffer at this level for the disk address we are * looking for re-use it. * * Otherwise throw it away and get a new one. */ bp = cur->bc_levels[level].bp; error = xfs_btree_ptr_to_daddr(cur, pp, &daddr); if (error) return error; if (bp && xfs_buf_daddr(bp) == daddr) { *blkp = XFS_BUF_TO_BLOCK(bp); return 0; } error = xfs_btree_read_buf_block(cur, pp, 0, blkp, &bp); if (error) return error; /* Check the inode owner since the verifiers don't. */ if (xfs_has_crc(cur->bc_mp) && !(cur->bc_ino.flags & XFS_BTCUR_BMBT_INVALID_OWNER) && (cur->bc_flags & XFS_BTREE_LONG_PTRS) && be64_to_cpu((*blkp)->bb_u.l.bb_owner) != cur->bc_ino.ip->i_ino) goto out_bad; /* Did we get the level we were looking for? */ if (be16_to_cpu((*blkp)->bb_level) != level) goto out_bad; /* Check that internal nodes have at least one record. */ if (level != 0 && be16_to_cpu((*blkp)->bb_numrecs) == 0) goto out_bad; xfs_btree_setbuf(cur, level, bp); return 0; out_bad: *blkp = NULL; xfs_buf_mark_corrupt(bp); xfs_trans_brelse(cur->bc_tp, bp); return -EFSCORRUPTED; } /* * Get current search key. For level 0 we don't actually have a key * structure so we make one up from the record. For all other levels * we just return the right key. */ STATIC union xfs_btree_key * xfs_lookup_get_search_key( struct xfs_btree_cur *cur, int level, int keyno, struct xfs_btree_block *block, union xfs_btree_key *kp) { if (level == 0) { cur->bc_ops->init_key_from_rec(kp, xfs_btree_rec_addr(cur, keyno, block)); return kp; } return xfs_btree_key_addr(cur, keyno, block); } /* * Lookup the record. The cursor is made to point to it, based on dir. * stat is set to 0 if can't find any such record, 1 for success. */ int /* error */ xfs_btree_lookup( struct xfs_btree_cur *cur, /* btree cursor */ xfs_lookup_t dir, /* <=, ==, or >= */ int *stat) /* success/failure */ { struct xfs_btree_block *block; /* current btree block */ int64_t diff; /* difference for the current key */ int error; /* error return value */ int keyno; /* current key number */ int level; /* level in the btree */ union xfs_btree_ptr *pp; /* ptr to btree block */ union xfs_btree_ptr ptr; /* ptr to btree block */ XFS_BTREE_STATS_INC(cur, lookup); /* No such thing as a zero-level tree. */ if (XFS_IS_CORRUPT(cur->bc_mp, cur->bc_nlevels == 0)) return -EFSCORRUPTED; block = NULL; keyno = 0; /* initialise start pointer from cursor */ cur->bc_ops->init_ptr_from_cur(cur, &ptr); pp = &ptr; /* * Iterate over each level in the btree, starting at the root. * For each level above the leaves, find the key we need, based * on the lookup record, then follow the corresponding block * pointer down to the next level. */ for (level = cur->bc_nlevels - 1, diff = 1; level >= 0; level--) { /* Get the block we need to do the lookup on. */ error = xfs_btree_lookup_get_block(cur, level, pp, &block); if (error) goto error0; if (diff == 0) { /* * If we already had a key match at a higher level, we * know we need to use the first entry in this block. */ keyno = 1; } else { /* Otherwise search this block. Do a binary search. */ int high; /* high entry number */ int low; /* low entry number */ /* Set low and high entry numbers, 1-based. */ low = 1; high = xfs_btree_get_numrecs(block); if (!high) { /* Block is empty, must be an empty leaf. */ if (level != 0 || cur->bc_nlevels != 1) { XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, cur->bc_mp, block, sizeof(*block)); return -EFSCORRUPTED; } cur->bc_levels[0].ptr = dir != XFS_LOOKUP_LE; *stat = 0; return 0; } /* Binary search the block. */ while (low <= high) { union xfs_btree_key key; union xfs_btree_key *kp; XFS_BTREE_STATS_INC(cur, compare); /* keyno is average of low and high. */ keyno = (low + high) >> 1; /* Get current search key */ kp = xfs_lookup_get_search_key(cur, level, keyno, block, &key); /* * Compute difference to get next direction: * - less than, move right * - greater than, move left * - equal, we're done */ diff = cur->bc_ops->key_diff(cur, kp); if (diff < 0) low = keyno + 1; else if (diff > 0) high = keyno - 1; else break; } } /* * If there are more levels, set up for the next level * by getting the block number and filling in the cursor. */ if (level > 0) { /* * If we moved left, need the previous key number, * unless there isn't one. */ if (diff > 0 && --keyno < 1) keyno = 1; pp = xfs_btree_ptr_addr(cur, keyno, block); error = xfs_btree_debug_check_ptr(cur, pp, 0, level); if (error) goto error0; cur->bc_levels[level].ptr = keyno; } } /* Done with the search. See if we need to adjust the results. */ if (dir != XFS_LOOKUP_LE && diff < 0) { keyno++; /* * If ge search and we went off the end of the block, but it's * not the last block, we're in the wrong block. */ xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB); if (dir == XFS_LOOKUP_GE && keyno > xfs_btree_get_numrecs(block) && !xfs_btree_ptr_is_null(cur, &ptr)) { int i; cur->bc_levels[0].ptr = keyno; error = xfs_btree_increment(cur, 0, &i); if (error) goto error0; if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) return -EFSCORRUPTED; *stat = 1; return 0; } } else if (dir == XFS_LOOKUP_LE && diff > 0) keyno--; cur->bc_levels[0].ptr = keyno; /* Return if we succeeded or not. */ if (keyno == 0 || keyno > xfs_btree_get_numrecs(block)) *stat = 0; else if (dir != XFS_LOOKUP_EQ || diff == 0) *stat = 1; else *stat = 0; return 0; error0: return error; } /* Find the high key storage area from a regular key. */ union xfs_btree_key * xfs_btree_high_key_from_key( struct xfs_btree_cur *cur, union xfs_btree_key *key) { ASSERT(cur->bc_flags & XFS_BTREE_OVERLAPPING); return (union xfs_btree_key *)((char *)key + (cur->bc_ops->key_len / 2)); } /* Determine the low (and high if overlapped) keys of a leaf block */ STATIC void xfs_btree_get_leaf_keys( struct xfs_btree_cur *cur, struct xfs_btree_block *block, union xfs_btree_key *key) { union xfs_btree_key max_hkey; union xfs_btree_key hkey; union xfs_btree_rec *rec; union xfs_btree_key *high; int n; rec = xfs_btree_rec_addr(cur, 1, block); cur->bc_ops->init_key_from_rec(key, rec); if (cur->bc_flags & XFS_BTREE_OVERLAPPING) { cur->bc_ops->init_high_key_from_rec(&max_hkey, rec); for (n = 2; n <= xfs_btree_get_numrecs(block); n++) { rec = xfs_btree_rec_addr(cur, n, block); cur->bc_ops->init_high_key_from_rec(&hkey, rec); if (xfs_btree_keycmp_gt(cur, &hkey, &max_hkey)) max_hkey = hkey; } high = xfs_btree_high_key_from_key(cur, key); memcpy(high, &max_hkey, cur->bc_ops->key_len / 2); } } /* Determine the low (and high if overlapped) keys of a node block */ STATIC void xfs_btree_get_node_keys( struct xfs_btree_cur *cur, struct xfs_btree_block *block, union xfs_btree_key *key) { union xfs_btree_key *hkey; union xfs_btree_key *max_hkey; union xfs_btree_key *high; int n; if (cur->bc_flags & XFS_BTREE_OVERLAPPING) { memcpy(key, xfs_btree_key_addr(cur, 1, block), cur->bc_ops->key_len / 2); max_hkey = xfs_btree_high_key_addr(cur, 1, block); for (n = 2; n <= xfs_btree_get_numrecs(block); n++) { hkey = xfs_btree_high_key_addr(cur, n, block); if (xfs_btree_keycmp_gt(cur, hkey, max_hkey)) max_hkey = hkey; } high = xfs_btree_high_key_from_key(cur, key); memcpy(high, max_hkey, cur->bc_ops->key_len / 2); } else { memcpy(key, xfs_btree_key_addr(cur, 1, block), cur->bc_ops->key_len); } } /* Derive the keys for any btree block. */ void xfs_btree_get_keys( struct xfs_btree_cur *cur, struct xfs_btree_block *block, union xfs_btree_key *key) { if (be16_to_cpu(block->bb_level) == 0) xfs_btree_get_leaf_keys(cur, block, key); else xfs_btree_get_node_keys(cur, block, key); } /* * Decide if we need to update the parent keys of a btree block. For * a standard btree this is only necessary if we're updating the first * record/key. For an overlapping btree, we must always update the * keys because the highest key can be in any of the records or keys * in the block. */ static inline bool xfs_btree_needs_key_update( struct xfs_btree_cur *cur, int ptr) { return (cur->bc_flags & XFS_BTREE_OVERLAPPING) || ptr == 1; } /* * Update the low and high parent keys of the given level, progressing * towards the root. If force_all is false, stop if the keys for a given * level do not need updating. */ STATIC int __xfs_btree_updkeys( struct xfs_btree_cur *cur, int level, struct xfs_btree_block *block, struct xfs_buf *bp0, bool force_all) { union xfs_btree_key key; /* keys from current level */ union xfs_btree_key *lkey; /* keys from the next level up */ union xfs_btree_key *hkey; union xfs_btree_key *nlkey; /* keys from the next level up */ union xfs_btree_key *nhkey; struct xfs_buf *bp; int ptr; ASSERT(cur->bc_flags & XFS_BTREE_OVERLAPPING); /* Exit if there aren't any parent levels to update. */ if (level + 1 >= cur->bc_nlevels) return 0; trace_xfs_btree_updkeys(cur, level, bp0); lkey = &key; hkey = xfs_btree_high_key_from_key(cur, lkey); xfs_btree_get_keys(cur, block, lkey); for (level++; level < cur->bc_nlevels; level++) { #ifdef DEBUG int error; #endif block = xfs_btree_get_block(cur, level, &bp); trace_xfs_btree_updkeys(cur, level, bp); #ifdef DEBUG error = xfs_btree_check_block(cur, block, level, bp); if (error) return error; #endif ptr = cur->bc_levels[level].ptr; nlkey = xfs_btree_key_addr(cur, ptr, block); nhkey = xfs_btree_high_key_addr(cur, ptr, block); if (!force_all && xfs_btree_keycmp_eq(cur, nlkey, lkey) && xfs_btree_keycmp_eq(cur, nhkey, hkey)) break; xfs_btree_copy_keys(cur, nlkey, lkey, 1); xfs_btree_log_keys(cur, bp, ptr, ptr); if (level + 1 >= cur->bc_nlevels) break; xfs_btree_get_node_keys(cur, block, lkey); } return 0; } /* Update all the keys from some level in cursor back to the root. */ STATIC int xfs_btree_updkeys_force( struct xfs_btree_cur *cur, int level) { struct xfs_buf *bp; struct xfs_btree_block *block; block = xfs_btree_get_block(cur, level, &bp); return __xfs_btree_updkeys(cur, level, block, bp, true); } /* * Update the parent keys of the given level, progressing towards the root. */ STATIC int xfs_btree_update_keys( struct xfs_btree_cur *cur, int level) { struct xfs_btree_block *block; struct xfs_buf *bp; union xfs_btree_key *kp; union xfs_btree_key key; int ptr; ASSERT(level >= 0); block = xfs_btree_get_block(cur, level, &bp); if (cur->bc_flags & XFS_BTREE_OVERLAPPING) return __xfs_btree_updkeys(cur, level, block, bp, false); /* * Go up the tree from this level toward the root. * At each level, update the key value to the value input. * Stop when we reach a level where the cursor isn't pointing * at the first entry in the block. */ xfs_btree_get_keys(cur, block, &key); for (level++, ptr = 1; ptr == 1 && level < cur->bc_nlevels; level++) { #ifdef DEBUG int error; #endif block = xfs_btree_get_block(cur, level, &bp); #ifdef DEBUG error = xfs_btree_check_block(cur, block, level, bp); if (error) return error; #endif ptr = cur->bc_levels[level].ptr; kp = xfs_btree_key_addr(cur, ptr, block); xfs_btree_copy_keys(cur, kp, &key, 1); xfs_btree_log_keys(cur, bp, ptr, ptr); } return 0; } /* * Update the record referred to by cur to the value in the * given record. This either works (return 0) or gets an * EFSCORRUPTED error. */ int xfs_btree_update( struct xfs_btree_cur *cur, union xfs_btree_rec *rec) { struct xfs_btree_block *block; struct xfs_buf *bp; int error; int ptr; union xfs_btree_rec *rp; /* Pick up the current block. */ block = xfs_btree_get_block(cur, 0, &bp); #ifdef DEBUG error = xfs_btree_check_block(cur, block, 0, bp); if (error) goto error0; #endif /* Get the address of the rec to be updated. */ ptr = cur->bc_levels[0].ptr; rp = xfs_btree_rec_addr(cur, ptr, block); /* Fill in the new contents and log them. */ xfs_btree_copy_recs(cur, rp, rec, 1); xfs_btree_log_recs(cur, bp, ptr, ptr); /* * If we are tracking the last record in the tree and * we are at the far right edge of the tree, update it. */ if (xfs_btree_is_lastrec(cur, block, 0)) { cur->bc_ops->update_lastrec(cur, block, rec, ptr, LASTREC_UPDATE); } /* Pass new key value up to our parent. */ if (xfs_btree_needs_key_update(cur, ptr)) { error = xfs_btree_update_keys(cur, 0); if (error) goto error0; } return 0; error0: return error; } /* * Move 1 record left from cur/level if possible. * Update cur to reflect the new path. */ STATIC int /* error */ xfs_btree_lshift( struct xfs_btree_cur *cur, int level, int *stat) /* success/failure */ { struct xfs_buf *lbp; /* left buffer pointer */ struct xfs_btree_block *left; /* left btree block */ int lrecs; /* left record count */ struct xfs_buf *rbp; /* right buffer pointer */ struct xfs_btree_block *right; /* right btree block */ struct xfs_btree_cur *tcur; /* temporary btree cursor */ int rrecs; /* right record count */ union xfs_btree_ptr lptr; /* left btree pointer */ union xfs_btree_key *rkp = NULL; /* right btree key */ union xfs_btree_ptr *rpp = NULL; /* right address pointer */ union xfs_btree_rec *rrp = NULL; /* right record pointer */ int error; /* error return value */ int i; if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) && level == cur->bc_nlevels - 1) goto out0; /* Set up variables for this block as "right". */ right = xfs_btree_get_block(cur, level, &rbp); #ifdef DEBUG error = xfs_btree_check_block(cur, right, level, rbp); if (error) goto error0; #endif /* If we've got no left sibling then we can't shift an entry left. */ xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB); if (xfs_btree_ptr_is_null(cur, &lptr)) goto out0; /* * If the cursor entry is the one that would be moved, don't * do it... it's too complicated. */ if (cur->bc_levels[level].ptr <= 1) goto out0; /* Set up the left neighbor as "left". */ error = xfs_btree_read_buf_block(cur, &lptr, 0, &left, &lbp); if (error) goto error0; /* If it's full, it can't take another entry. */ lrecs = xfs_btree_get_numrecs(left); if (lrecs == cur->bc_ops->get_maxrecs(cur, level)) goto out0; rrecs = xfs_btree_get_numrecs(right); /* * We add one entry to the left side and remove one for the right side. * Account for it here, the changes will be updated on disk and logged * later. */ lrecs++; rrecs--; XFS_BTREE_STATS_INC(cur, lshift); XFS_BTREE_STATS_ADD(cur, moves, 1); /* * If non-leaf, copy a key and a ptr to the left block. * Log the changes to the left block. */ if (level > 0) { /* It's a non-leaf. Move keys and pointers. */ union xfs_btree_key *lkp; /* left btree key */ union xfs_btree_ptr *lpp; /* left address pointer */ lkp = xfs_btree_key_addr(cur, lrecs, left); rkp = xfs_btree_key_addr(cur, 1, right); lpp = xfs_btree_ptr_addr(cur, lrecs, left); rpp = xfs_btree_ptr_addr(cur, 1, right); error = xfs_btree_debug_check_ptr(cur, rpp, 0, level); if (error) goto error0; xfs_btree_copy_keys(cur, lkp, rkp, 1); xfs_btree_copy_ptrs(cur, lpp, rpp, 1); xfs_btree_log_keys(cur, lbp, lrecs, lrecs); xfs_btree_log_ptrs(cur, lbp, lrecs, lrecs); ASSERT(cur->bc_ops->keys_inorder(cur, xfs_btree_key_addr(cur, lrecs - 1, left), lkp)); } else { /* It's a leaf. Move records. */ union xfs_btree_rec *lrp; /* left record pointer */ lrp = xfs_btree_rec_addr(cur, lrecs, left); rrp = xfs_btree_rec_addr(cur, 1, right); xfs_btree_copy_recs(cur, lrp, rrp, 1); xfs_btree_log_recs(cur, lbp, lrecs, lrecs); ASSERT(cur->bc_ops->recs_inorder(cur, xfs_btree_rec_addr(cur, lrecs - 1, left), lrp)); } xfs_btree_set_numrecs(left, lrecs); xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS); xfs_btree_set_numrecs(right, rrecs); xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS); /* * Slide the contents of right down one entry. */ XFS_BTREE_STATS_ADD(cur, moves, rrecs - 1); if (level > 0) { /* It's a nonleaf. operate on keys and ptrs */ for (i = 0; i < rrecs; i++) { error = xfs_btree_debug_check_ptr(cur, rpp, i + 1, level); if (error) goto error0; } xfs_btree_shift_keys(cur, xfs_btree_key_addr(cur, 2, right), -1, rrecs); xfs_btree_shift_ptrs(cur, xfs_btree_ptr_addr(cur, 2, right), -1, rrecs); xfs_btree_log_keys(cur, rbp, 1, rrecs); xfs_btree_log_ptrs(cur, rbp, 1, rrecs); } else { /* It's a leaf. operate on records */ xfs_btree_shift_recs(cur, xfs_btree_rec_addr(cur, 2, right), -1, rrecs); xfs_btree_log_recs(cur, rbp, 1, rrecs); } /* * Using a temporary cursor, update the parent key values of the * block on the left. */ if (cur->bc_flags & XFS_BTREE_OVERLAPPING) { error = xfs_btree_dup_cursor(cur, &tcur); if (error) goto error0; i = xfs_btree_firstrec(tcur, level); if (XFS_IS_CORRUPT(tcur->bc_mp, i != 1)) { error = -EFSCORRUPTED; goto error0; } error = xfs_btree_decrement(tcur, level, &i); if (error) goto error1; /* Update the parent high keys of the left block, if needed. */ error = xfs_btree_update_keys(tcur, level); if (error) goto error1; xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR); } /* Update the parent keys of the right block. */ error = xfs_btree_update_keys(cur, level); if (error) goto error0; /* Slide the cursor value left one. */ cur->bc_levels[level].ptr--; *stat = 1; return 0; out0: *stat = 0; return 0; error0: return error; error1: xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR); return error; } /* * Move 1 record right from cur/level if possible. * Update cur to reflect the new path. */ STATIC int /* error */ xfs_btree_rshift( struct xfs_btree_cur *cur, int level, int *stat) /* success/failure */ { struct xfs_buf *lbp; /* left buffer pointer */ struct xfs_btree_block *left; /* left btree block */ struct xfs_buf *rbp; /* right buffer pointer */ struct xfs_btree_block *right; /* right btree block */ struct xfs_btree_cur *tcur; /* temporary btree cursor */ union xfs_btree_ptr rptr; /* right block pointer */ union xfs_btree_key *rkp; /* right btree key */ int rrecs; /* right record count */ int lrecs; /* left record count */ int error; /* error return value */ int i; /* loop counter */ if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) && (level == cur->bc_nlevels - 1)) goto out0; /* Set up variables for this block as "left". */ left = xfs_btree_get_block(cur, level, &lbp); #ifdef DEBUG error = xfs_btree_check_block(cur, left, level, lbp); if (error) goto error0; #endif /* If we've got no right sibling then we can't shift an entry right. */ xfs_btree_get_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB); if (xfs_btree_ptr_is_null(cur, &rptr)) goto out0; /* * If the cursor entry is the one that would be moved, don't * do it... it's too complicated. */ lrecs = xfs_btree_get_numrecs(left); if (cur->bc_levels[level].ptr >= lrecs) goto out0; /* Set up the right neighbor as "right". */ error = xfs_btree_read_buf_block(cur, &rptr, 0, &right, &rbp); if (error) goto error0; /* If it's full, it can't take another entry. */ rrecs = xfs_btree_get_numrecs(right); if (rrecs == cur->bc_ops->get_maxrecs(cur, level)) goto out0; XFS_BTREE_STATS_INC(cur, rshift); XFS_BTREE_STATS_ADD(cur, moves, rrecs); /* * Make a hole at the start of the right neighbor block, then * copy the last left block entry to the hole. */ if (level > 0) { /* It's a nonleaf. make a hole in the keys and ptrs */ union xfs_btree_key *lkp; union xfs_btree_ptr *lpp; union xfs_btree_ptr *rpp; lkp = xfs_btree_key_addr(cur, lrecs, left); lpp = xfs_btree_ptr_addr(cur, lrecs, left); rkp = xfs_btree_key_addr(cur, 1, right); rpp = xfs_btree_ptr_addr(cur, 1, right); for (i = rrecs - 1; i >= 0; i--) { error = xfs_btree_debug_check_ptr(cur, rpp, i, level); if (error) goto error0; } xfs_btree_shift_keys(cur, rkp, 1, rrecs); xfs_btree_shift_ptrs(cur, rpp, 1, rrecs); error = xfs_btree_debug_check_ptr(cur, lpp, 0, level); if (error) goto error0; /* Now put the new data in, and log it. */ xfs_btree_copy_keys(cur, rkp, lkp, 1); xfs_btree_copy_ptrs(cur, rpp, lpp, 1); xfs_btree_log_keys(cur, rbp, 1, rrecs + 1); xfs_btree_log_ptrs(cur, rbp, 1, rrecs + 1); ASSERT(cur->bc_ops->keys_inorder(cur, rkp, xfs_btree_key_addr(cur, 2, right))); } else { /* It's a leaf. make a hole in the records */ union xfs_btree_rec *lrp; union xfs_btree_rec *rrp; lrp = xfs_btree_rec_addr(cur, lrecs, left); rrp = xfs_btree_rec_addr(cur, 1, right); xfs_btree_shift_recs(cur, rrp, 1, rrecs); /* Now put the new data in, and log it. */ xfs_btree_copy_recs(cur, rrp, lrp, 1); xfs_btree_log_recs(cur, rbp, 1, rrecs + 1); } /* * Decrement and log left's numrecs, bump and log right's numrecs. */ xfs_btree_set_numrecs(left, --lrecs); xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS); xfs_btree_set_numrecs(right, ++rrecs); xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS); /* * Using a temporary cursor, update the parent key values of the * block on the right. */ error = xfs_btree_dup_cursor(cur, &tcur); if (error) goto error0; i = xfs_btree_lastrec(tcur, level); if (XFS_IS_CORRUPT(tcur->bc_mp, i != 1)) { error = -EFSCORRUPTED; goto error0; } error = xfs_btree_increment(tcur, level, &i); if (error) goto error1; /* Update the parent high keys of the left block, if needed. */ if (cur->bc_flags & XFS_BTREE_OVERLAPPING) { error = xfs_btree_update_keys(cur, level); if (error) goto error1; } /* Update the parent keys of the right block. */ error = xfs_btree_update_keys(tcur, level); if (error) goto error1; xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR); *stat = 1; return 0; out0: *stat = 0; return 0; error0: return error; error1: xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR); return error; } /* * Split cur/level block in half. * Return new block number and the key to its first * record (to be inserted into parent). */ STATIC int /* error */ __xfs_btree_split( struct xfs_btree_cur *cur, int level, union xfs_btree_ptr *ptrp, union xfs_btree_key *key, struct xfs_btree_cur **curp, int *stat) /* success/failure */ { union xfs_btree_ptr lptr; /* left sibling block ptr */ struct xfs_buf *lbp; /* left buffer pointer */ struct xfs_btree_block *left; /* left btree block */ union xfs_btree_ptr rptr; /* right sibling block ptr */ struct xfs_buf *rbp; /* right buffer pointer */ struct xfs_btree_block *right; /* right btree block */ union xfs_btree_ptr rrptr; /* right-right sibling ptr */ struct xfs_buf *rrbp; /* right-right buffer pointer */ struct xfs_btree_block *rrblock; /* right-right btree block */ int lrecs; int rrecs; int src_index; int error; /* error return value */ int i; XFS_BTREE_STATS_INC(cur, split); /* Set up left block (current one). */ left = xfs_btree_get_block(cur, level, &lbp); #ifdef DEBUG error = xfs_btree_check_block(cur, left, level, lbp); if (error) goto error0; #endif xfs_btree_buf_to_ptr(cur, lbp, &lptr); /* Allocate the new block. If we can't do it, we're toast. Give up. */ error = cur->bc_ops->alloc_block(cur, &lptr, &rptr, stat); if (error) goto error0; if (*stat == 0) goto out0; XFS_BTREE_STATS_INC(cur, alloc); /* Set up the new block as "right". */ error = xfs_btree_get_buf_block(cur, &rptr, &right, &rbp); if (error) goto error0; /* Fill in the btree header for the new right block. */ xfs_btree_init_block_cur(cur, rbp, xfs_btree_get_level(left), 0); /* * Split the entries between the old and the new block evenly. * Make sure that if there's an odd number of entries now, that * each new block will have the same number of entries. */ lrecs = xfs_btree_get_numrecs(left); rrecs = lrecs / 2; if ((lrecs & 1) && cur->bc_levels[level].ptr <= rrecs + 1) rrecs++; src_index = (lrecs - rrecs + 1); XFS_BTREE_STATS_ADD(cur, moves, rrecs); /* Adjust numrecs for the later get_*_keys() calls. */ lrecs -= rrecs; xfs_btree_set_numrecs(left, lrecs); xfs_btree_set_numrecs(right, xfs_btree_get_numrecs(right) + rrecs); /* * Copy btree block entries from the left block over to the * new block, the right. Update the right block and log the * changes. */ if (level > 0) { /* It's a non-leaf. Move keys and pointers. */ union xfs_btree_key *lkp; /* left btree key */ union xfs_btree_ptr *lpp; /* left address pointer */ union xfs_btree_key *rkp; /* right btree key */ union xfs_btree_ptr *rpp; /* right address pointer */ lkp = xfs_btree_key_addr(cur, src_index, left); lpp = xfs_btree_ptr_addr(cur, src_index, left); rkp = xfs_btree_key_addr(cur, 1, right); rpp = xfs_btree_ptr_addr(cur, 1, right); for (i = src_index; i < rrecs; i++) { error = xfs_btree_debug_check_ptr(cur, lpp, i, level); if (error) goto error0; } /* Copy the keys & pointers to the new block. */ xfs_btree_copy_keys(cur, rkp, lkp, rrecs); xfs_btree_copy_ptrs(cur, rpp, lpp, rrecs); xfs_btree_log_keys(cur, rbp, 1, rrecs); xfs_btree_log_ptrs(cur, rbp, 1, rrecs); /* Stash the keys of the new block for later insertion. */ xfs_btree_get_node_keys(cur, right, key); } else { /* It's a leaf. Move records. */ union xfs_btree_rec *lrp; /* left record pointer */ union xfs_btree_rec *rrp; /* right record pointer */ lrp = xfs_btree_rec_addr(cur, src_index, left); rrp = xfs_btree_rec_addr(cur, 1, right); /* Copy records to the new block. */ xfs_btree_copy_recs(cur, rrp, lrp, rrecs); xfs_btree_log_recs(cur, rbp, 1, rrecs); /* Stash the keys of the new block for later insertion. */ xfs_btree_get_leaf_keys(cur, right, key); } /* * Find the left block number by looking in the buffer. * Adjust sibling pointers. */ xfs_btree_get_sibling(cur, left, &rrptr, XFS_BB_RIGHTSIB); xfs_btree_set_sibling(cur, right, &rrptr, XFS_BB_RIGHTSIB); xfs_btree_set_sibling(cur, right, &lptr, XFS_BB_LEFTSIB); xfs_btree_set_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB); xfs_btree_log_block(cur, rbp, XFS_BB_ALL_BITS); xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB); /* * If there's a block to the new block's right, make that block * point back to right instead of to left. */ if (!xfs_btree_ptr_is_null(cur, &rrptr)) { error = xfs_btree_read_buf_block(cur, &rrptr, 0, &rrblock, &rrbp); if (error) goto error0; xfs_btree_set_sibling(cur, rrblock, &rptr, XFS_BB_LEFTSIB); xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB); } /* Update the parent high keys of the left block, if needed. */ if (cur->bc_flags & XFS_BTREE_OVERLAPPING) { error = xfs_btree_update_keys(cur, level); if (error) goto error0; } /* * If the cursor is really in the right block, move it there. * If it's just pointing past the last entry in left, then we'll * insert there, so don't change anything in that case. */ if (cur->bc_levels[level].ptr > lrecs + 1) { xfs_btree_setbuf(cur, level, rbp); cur->bc_levels[level].ptr -= lrecs; } /* * If there are more levels, we'll need another cursor which refers * the right block, no matter where this cursor was. */ if (level + 1 < cur->bc_nlevels) { error = xfs_btree_dup_cursor(cur, curp); if (error) goto error0; (*curp)->bc_levels[level + 1].ptr++; } *ptrp = rptr; *stat = 1; return 0; out0: *stat = 0; return 0; error0: return error; } #ifdef __KERNEL__ struct xfs_btree_split_args { struct xfs_btree_cur *cur; int level; union xfs_btree_ptr *ptrp; union xfs_btree_key *key; struct xfs_btree_cur **curp; int *stat; /* success/failure */ int result; bool kswapd; /* allocation in kswapd context */ struct completion *done; struct work_struct work; }; /* * Stack switching interfaces for allocation */ static void xfs_btree_split_worker( struct work_struct *work) { struct xfs_btree_split_args *args = container_of(work, struct xfs_btree_split_args, work); unsigned long pflags; unsigned long new_pflags = 0; /* * we are in a transaction context here, but may also be doing work * in kswapd context, and hence we may need to inherit that state * temporarily to ensure that we don't block waiting for memory reclaim * in any way. */ if (args->kswapd) new_pflags |= PF_MEMALLOC | PF_KSWAPD; current_set_flags_nested(&pflags, new_pflags); xfs_trans_set_context(args->cur->bc_tp); args->result = __xfs_btree_split(args->cur, args->level, args->ptrp, args->key, args->curp, args->stat); xfs_trans_clear_context(args->cur->bc_tp); current_restore_flags_nested(&pflags, new_pflags); /* * Do not access args after complete() has run here. We don't own args * and the owner may run and free args before we return here. */ complete(args->done); } /* * BMBT split requests often come in with little stack to work on so we push * them off to a worker thread so there is lots of stack to use. For the other * btree types, just call directly to avoid the context switch overhead here. * * Care must be taken here - the work queue rescuer thread introduces potential * AGF <> worker queue deadlocks if the BMBT block allocation has to lock new * AGFs to allocate blocks. A task being run by the rescuer could attempt to * lock an AGF that is already locked by a task queued to run by the rescuer, * resulting in an ABBA deadlock as the rescuer cannot run the lock holder to * release it until the current thread it is running gains the lock. * * To avoid this issue, we only ever queue BMBT splits that don't have an AGF * already locked to allocate from. The only place that doesn't hold an AGF * locked is unwritten extent conversion at IO completion, but that has already * been offloaded to a worker thread and hence has no stack consumption issues * we have to worry about. */ STATIC int /* error */ xfs_btree_split( struct xfs_btree_cur *cur, int level, union xfs_btree_ptr *ptrp, union xfs_btree_key *key, struct xfs_btree_cur **curp, int *stat) /* success/failure */ { struct xfs_btree_split_args args; DECLARE_COMPLETION_ONSTACK(done); if (cur->bc_btnum != XFS_BTNUM_BMAP || cur->bc_tp->t_highest_agno == NULLAGNUMBER) return __xfs_btree_split(cur, level, ptrp, key, curp, stat); args.cur = cur; args.level = level; args.ptrp = ptrp; args.key = key; args.curp = curp; args.stat = stat; args.done = &done; args.kswapd = current_is_kswapd(); INIT_WORK_ONSTACK(&args.work, xfs_btree_split_worker); queue_work(xfs_alloc_wq, &args.work); wait_for_completion(&done); destroy_work_on_stack(&args.work); return args.result; } #else #define xfs_btree_split __xfs_btree_split #endif /* __KERNEL__ */ /* * Copy the old inode root contents into a real block and make the * broot point to it. */ int /* error */ xfs_btree_new_iroot( struct xfs_btree_cur *cur, /* btree cursor */ int *logflags, /* logging flags for inode */ int *stat) /* return status - 0 fail */ { struct xfs_buf *cbp; /* buffer for cblock */ struct xfs_btree_block *block; /* btree block */ struct xfs_btree_block *cblock; /* child btree block */ union xfs_btree_key *ckp; /* child key pointer */ union xfs_btree_ptr *cpp; /* child ptr pointer */ union xfs_btree_key *kp; /* pointer to btree key */ union xfs_btree_ptr *pp; /* pointer to block addr */ union xfs_btree_ptr nptr; /* new block addr */ int level; /* btree level */ int error; /* error return code */ int i; /* loop counter */ XFS_BTREE_STATS_INC(cur, newroot); ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE); level = cur->bc_nlevels - 1; block = xfs_btree_get_iroot(cur); pp = xfs_btree_ptr_addr(cur, 1, block); /* Allocate the new block. If we can't do it, we're toast. Give up. */ error = cur->bc_ops->alloc_block(cur, pp, &nptr, stat); if (error) goto error0; if (*stat == 0) return 0; XFS_BTREE_STATS_INC(cur, alloc); /* Copy the root into a real block. */ error = xfs_btree_get_buf_block(cur, &nptr, &cblock, &cbp); if (error) goto error0; /* * we can't just memcpy() the root in for CRC enabled btree blocks. * In that case have to also ensure the blkno remains correct */ memcpy(cblock, block, xfs_btree_block_len(cur)); if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS) { __be64 bno = cpu_to_be64(xfs_buf_daddr(cbp)); if (cur->bc_flags & XFS_BTREE_LONG_PTRS) cblock->bb_u.l.bb_blkno = bno; else cblock->bb_u.s.bb_blkno = bno; } be16_add_cpu(&block->bb_level, 1); xfs_btree_set_numrecs(block, 1); cur->bc_nlevels++; ASSERT(cur->bc_nlevels <= cur->bc_maxlevels); cur->bc_levels[level + 1].ptr = 1; kp = xfs_btree_key_addr(cur, 1, block); ckp = xfs_btree_key_addr(cur, 1, cblock); xfs_btree_copy_keys(cur, ckp, kp, xfs_btree_get_numrecs(cblock)); cpp = xfs_btree_ptr_addr(cur, 1, cblock); for (i = 0; i < be16_to_cpu(cblock->bb_numrecs); i++) { error = xfs_btree_debug_check_ptr(cur, pp, i, level); if (error) goto error0; } xfs_btree_copy_ptrs(cur, cpp, pp, xfs_btree_get_numrecs(cblock)); error = xfs_btree_debug_check_ptr(cur, &nptr, 0, level); if (error) goto error0; xfs_btree_copy_ptrs(cur, pp, &nptr, 1); xfs_iroot_realloc(cur->bc_ino.ip, 1 - xfs_btree_get_numrecs(cblock), cur->bc_ino.whichfork); xfs_btree_setbuf(cur, level, cbp); /* * Do all this logging at the end so that * the root is at the right level. */ xfs_btree_log_block(cur, cbp, XFS_BB_ALL_BITS); xfs_btree_log_keys(cur, cbp, 1, be16_to_cpu(cblock->bb_numrecs)); xfs_btree_log_ptrs(cur, cbp, 1, be16_to_cpu(cblock->bb_numrecs)); *logflags |= XFS_ILOG_CORE | xfs_ilog_fbroot(cur->bc_ino.whichfork); *stat = 1; return 0; error0: return error; } /* * Allocate a new root block, fill it in. */ STATIC int /* error */ xfs_btree_new_root( struct xfs_btree_cur *cur, /* btree cursor */ int *stat) /* success/failure */ { struct xfs_btree_block *block; /* one half of the old root block */ struct xfs_buf *bp; /* buffer containing block */ int error; /* error return value */ struct xfs_buf *lbp; /* left buffer pointer */ struct xfs_btree_block *left; /* left btree block */ struct xfs_buf *nbp; /* new (root) buffer */ struct xfs_btree_block *new; /* new (root) btree block */ int nptr; /* new value for key index, 1 or 2 */ struct xfs_buf *rbp; /* right buffer pointer */ struct xfs_btree_block *right; /* right btree block */ union xfs_btree_ptr rptr; union xfs_btree_ptr lptr; XFS_BTREE_STATS_INC(cur, newroot); /* initialise our start point from the cursor */ cur->bc_ops->init_ptr_from_cur(cur, &rptr); /* Allocate the new block. If we can't do it, we're toast. Give up. */ error = cur->bc_ops->alloc_block(cur, &rptr, &lptr, stat); if (error) goto error0; if (*stat == 0) goto out0; XFS_BTREE_STATS_INC(cur, alloc); /* Set up the new block. */ error = xfs_btree_get_buf_block(cur, &lptr, &new, &nbp); if (error) goto error0; /* Set the root in the holding structure increasing the level by 1. */ cur->bc_ops->set_root(cur, &lptr, 1); /* * At the previous root level there are now two blocks: the old root, * and the new block generated when it was split. We don't know which * one the cursor is pointing at, so we set up variables "left" and * "right" for each case. */ block = xfs_btree_get_block(cur, cur->bc_nlevels - 1, &bp); #ifdef DEBUG error = xfs_btree_check_block(cur, block, cur->bc_nlevels - 1, bp); if (error) goto error0; #endif xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB); if (!xfs_btree_ptr_is_null(cur, &rptr)) { /* Our block is left, pick up the right block. */ lbp = bp; xfs_btree_buf_to_ptr(cur, lbp, &lptr); left = block; error = xfs_btree_read_buf_block(cur, &rptr, 0, &right, &rbp); if (error) goto error0; bp = rbp; nptr = 1; } else { /* Our block is right, pick up the left block. */ rbp = bp; xfs_btree_buf_to_ptr(cur, rbp, &rptr); right = block; xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB); error = xfs_btree_read_buf_block(cur, &lptr, 0, &left, &lbp); if (error) goto error0; bp = lbp; nptr = 2; } /* Fill in the new block's btree header and log it. */ xfs_btree_init_block_cur(cur, nbp, cur->bc_nlevels, 2); xfs_btree_log_block(cur, nbp, XFS_BB_ALL_BITS); ASSERT(!xfs_btree_ptr_is_null(cur, &lptr) && !xfs_btree_ptr_is_null(cur, &rptr)); /* Fill in the key data in the new root. */ if (xfs_btree_get_level(left) > 0) { /* * Get the keys for the left block's keys and put them directly * in the parent block. Do the same for the right block. */ xfs_btree_get_node_keys(cur, left, xfs_btree_key_addr(cur, 1, new)); xfs_btree_get_node_keys(cur, right, xfs_btree_key_addr(cur, 2, new)); } else { /* * Get the keys for the left block's records and put them * directly in the parent block. Do the same for the right * block. */ xfs_btree_get_leaf_keys(cur, left, xfs_btree_key_addr(cur, 1, new)); xfs_btree_get_leaf_keys(cur, right, xfs_btree_key_addr(cur, 2, new)); } xfs_btree_log_keys(cur, nbp, 1, 2); /* Fill in the pointer data in the new root. */ xfs_btree_copy_ptrs(cur, xfs_btree_ptr_addr(cur, 1, new), &lptr, 1); xfs_btree_copy_ptrs(cur, xfs_btree_ptr_addr(cur, 2, new), &rptr, 1); xfs_btree_log_ptrs(cur, nbp, 1, 2); /* Fix up the cursor. */ xfs_btree_setbuf(cur, cur->bc_nlevels, nbp); cur->bc_levels[cur->bc_nlevels].ptr = nptr; cur->bc_nlevels++; ASSERT(cur->bc_nlevels <= cur->bc_maxlevels); *stat = 1; return 0; error0: return error; out0: *stat = 0; return 0; } STATIC int xfs_btree_make_block_unfull( struct xfs_btree_cur *cur, /* btree cursor */ int level, /* btree level */ int numrecs,/* # of recs in block */ int *oindex,/* old tree index */ int *index, /* new tree index */ union xfs_btree_ptr *nptr, /* new btree ptr */ struct xfs_btree_cur **ncur, /* new btree cursor */ union xfs_btree_key *key, /* key of new block */ int *stat) { int error = 0; if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) && level == cur->bc_nlevels - 1) { struct xfs_inode *ip = cur->bc_ino.ip; if (numrecs < cur->bc_ops->get_dmaxrecs(cur, level)) { /* A root block that can be made bigger. */ xfs_iroot_realloc(ip, 1, cur->bc_ino.whichfork); *stat = 1; } else { /* A root block that needs replacing */ int logflags = 0; error = xfs_btree_new_iroot(cur, &logflags, stat); if (error || *stat == 0) return error; xfs_trans_log_inode(cur->bc_tp, ip, logflags); } return 0; } /* First, try shifting an entry to the right neighbor. */ error = xfs_btree_rshift(cur, level, stat); if (error || *stat) return error; /* Next, try shifting an entry to the left neighbor. */ error = xfs_btree_lshift(cur, level, stat); if (error) return error; if (*stat) { *oindex = *index = cur->bc_levels[level].ptr; return 0; } /* * Next, try splitting the current block in half. * * If this works we have to re-set our variables because we * could be in a different block now. */ error = xfs_btree_split(cur, level, nptr, key, ncur, stat); if (error || *stat == 0) return error; *index = cur->bc_levels[level].ptr; return 0; } /* * Insert one record/level. Return information to the caller * allowing the next level up to proceed if necessary. */ STATIC int xfs_btree_insrec( struct xfs_btree_cur *cur, /* btree cursor */ int level, /* level to insert record at */ union xfs_btree_ptr *ptrp, /* i/o: block number inserted */ union xfs_btree_rec *rec, /* record to insert */ union xfs_btree_key *key, /* i/o: block key for ptrp */ struct xfs_btree_cur **curp, /* output: new cursor replacing cur */ int *stat) /* success/failure */ { struct xfs_btree_block *block; /* btree block */ struct xfs_buf *bp; /* buffer for block */ union xfs_btree_ptr nptr; /* new block ptr */ struct xfs_btree_cur *ncur = NULL; /* new btree cursor */ union xfs_btree_key nkey; /* new block key */ union xfs_btree_key *lkey; int optr; /* old key/record index */ int ptr; /* key/record index */ int numrecs;/* number of records */ int error; /* error return value */ int i; xfs_daddr_t old_bn; ncur = NULL; lkey = &nkey; /* * If we have an external root pointer, and we've made it to the * root level, allocate a new root block and we're done. */ if (!(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) && (level >= cur->bc_nlevels)) { error = xfs_btree_new_root(cur, stat); xfs_btree_set_ptr_null(cur, ptrp); return error; } /* If we're off the left edge, return failure. */ ptr = cur->bc_levels[level].ptr; if (ptr == 0) { *stat = 0; return 0; } optr = ptr; XFS_BTREE_STATS_INC(cur, insrec); /* Get pointers to the btree buffer and block. */ block = xfs_btree_get_block(cur, level, &bp); old_bn = bp ? xfs_buf_daddr(bp) : XFS_BUF_DADDR_NULL; numrecs = xfs_btree_get_numrecs(block); #ifdef DEBUG error = xfs_btree_check_block(cur, block, level, bp); if (error) goto error0; /* Check that the new entry is being inserted in the right place. */ if (ptr <= numrecs) { if (level == 0) { ASSERT(cur->bc_ops->recs_inorder(cur, rec, xfs_btree_rec_addr(cur, ptr, block))); } else { ASSERT(cur->bc_ops->keys_inorder(cur, key, xfs_btree_key_addr(cur, ptr, block))); } } #endif /* * If the block is full, we can't insert the new entry until we * make the block un-full. */ xfs_btree_set_ptr_null(cur, &nptr); if (numrecs == cur->bc_ops->get_maxrecs(cur, level)) { error = xfs_btree_make_block_unfull(cur, level, numrecs, &optr, &ptr, &nptr, &ncur, lkey, stat); if (error || *stat == 0) goto error0; } /* * The current block may have changed if the block was * previously full and we have just made space in it. */ block = xfs_btree_get_block(cur, level, &bp); numrecs = xfs_btree_get_numrecs(block); #ifdef DEBUG error = xfs_btree_check_block(cur, block, level, bp); if (error) goto error0; #endif /* * At this point we know there's room for our new entry in the block * we're pointing at. */ XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr + 1); if (level > 0) { /* It's a nonleaf. make a hole in the keys and ptrs */ union xfs_btree_key *kp; union xfs_btree_ptr *pp; kp = xfs_btree_key_addr(cur, ptr, block); pp = xfs_btree_ptr_addr(cur, ptr, block); for (i = numrecs - ptr; i >= 0; i--) { error = xfs_btree_debug_check_ptr(cur, pp, i, level); if (error) goto error0; } xfs_btree_shift_keys(cur, kp, 1, numrecs - ptr + 1); xfs_btree_shift_ptrs(cur, pp, 1, numrecs - ptr + 1); error = xfs_btree_debug_check_ptr(cur, ptrp, 0, level); if (error) goto error0; /* Now put the new data in, bump numrecs and log it. */ xfs_btree_copy_keys(cur, kp, key, 1); xfs_btree_copy_ptrs(cur, pp, ptrp, 1); numrecs++; xfs_btree_set_numrecs(block, numrecs); xfs_btree_log_ptrs(cur, bp, ptr, numrecs); xfs_btree_log_keys(cur, bp, ptr, numrecs); #ifdef DEBUG if (ptr < numrecs) { ASSERT(cur->bc_ops->keys_inorder(cur, kp, xfs_btree_key_addr(cur, ptr + 1, block))); } #endif } else { /* It's a leaf. make a hole in the records */ union xfs_btree_rec *rp; rp = xfs_btree_rec_addr(cur, ptr, block); xfs_btree_shift_recs(cur, rp, 1, numrecs - ptr + 1); /* Now put the new data in, bump numrecs and log it. */ xfs_btree_copy_recs(cur, rp, rec, 1); xfs_btree_set_numrecs(block, ++numrecs); xfs_btree_log_recs(cur, bp, ptr, numrecs); #ifdef DEBUG if (ptr < numrecs) { ASSERT(cur->bc_ops->recs_inorder(cur, rp, xfs_btree_rec_addr(cur, ptr + 1, block))); } #endif } /* Log the new number of records in the btree header. */ xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS); /* * If we just inserted into a new tree block, we have to * recalculate nkey here because nkey is out of date. * * Otherwise we're just updating an existing block (having shoved * some records into the new tree block), so use the regular key * update mechanism. */ if (bp && xfs_buf_daddr(bp) != old_bn) { xfs_btree_get_keys(cur, block, lkey); } else if (xfs_btree_needs_key_update(cur, optr)) { error = xfs_btree_update_keys(cur, level); if (error) goto error0; } /* * If we are tracking the last record in the tree and * we are at the far right edge of the tree, update it. */ if (xfs_btree_is_lastrec(cur, block, level)) { cur->bc_ops->update_lastrec(cur, block, rec, ptr, LASTREC_INSREC); } /* * Return the new block number, if any. * If there is one, give back a record value and a cursor too. */ *ptrp = nptr; if (!xfs_btree_ptr_is_null(cur, &nptr)) { xfs_btree_copy_keys(cur, key, lkey, 1); *curp = ncur; } *stat = 1; return 0; error0: if (ncur) xfs_btree_del_cursor(ncur, error); return error; } /* * Insert the record at the point referenced by cur. * * A multi-level split of the tree on insert will invalidate the original * cursor. All callers of this function should assume that the cursor is * no longer valid and revalidate it. */ int xfs_btree_insert( struct xfs_btree_cur *cur, int *stat) { int error; /* error return value */ int i; /* result value, 0 for failure */ int level; /* current level number in btree */ union xfs_btree_ptr nptr; /* new block number (split result) */ struct xfs_btree_cur *ncur; /* new cursor (split result) */ struct xfs_btree_cur *pcur; /* previous level's cursor */ union xfs_btree_key bkey; /* key of block to insert */ union xfs_btree_key *key; union xfs_btree_rec rec; /* record to insert */ level = 0; ncur = NULL; pcur = cur; key = &bkey; xfs_btree_set_ptr_null(cur, &nptr); /* Make a key out of the record data to be inserted, and save it. */ cur->bc_ops->init_rec_from_cur(cur, &rec); cur->bc_ops->init_key_from_rec(key, &rec); /* * Loop going up the tree, starting at the leaf level. * Stop when we don't get a split block, that must mean that * the insert is finished with this level. */ do { /* * Insert nrec/nptr into this level of the tree. * Note if we fail, nptr will be null. */ error = xfs_btree_insrec(pcur, level, &nptr, &rec, key, &ncur, &i); if (error) { if (pcur != cur) xfs_btree_del_cursor(pcur, XFS_BTREE_ERROR); goto error0; } if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) { error = -EFSCORRUPTED; goto error0; } level++; /* * See if the cursor we just used is trash. * Can't trash the caller's cursor, but otherwise we should * if ncur is a new cursor or we're about to be done. */ if (pcur != cur && (ncur || xfs_btree_ptr_is_null(cur, &nptr))) { /* Save the state from the cursor before we trash it */ if (cur->bc_ops->update_cursor) cur->bc_ops->update_cursor(pcur, cur); cur->bc_nlevels = pcur->bc_nlevels; xfs_btree_del_cursor(pcur, XFS_BTREE_NOERROR); } /* If we got a new cursor, switch to it. */ if (ncur) { pcur = ncur; ncur = NULL; } } while (!xfs_btree_ptr_is_null(cur, &nptr)); *stat = i; return 0; error0: return error; } /* * Try to merge a non-leaf block back into the inode root. * * Note: the killroot names comes from the fact that we're effectively * killing the old root block. But because we can't just delete the * inode we have to copy the single block it was pointing to into the * inode. */ STATIC int xfs_btree_kill_iroot( struct xfs_btree_cur *cur) { int whichfork = cur->bc_ino.whichfork; struct xfs_inode *ip = cur->bc_ino.ip; struct xfs_ifork *ifp = xfs_ifork_ptr(ip, whichfork); struct xfs_btree_block *block; struct xfs_btree_block *cblock; union xfs_btree_key *kp; union xfs_btree_key *ckp; union xfs_btree_ptr *pp; union xfs_btree_ptr *cpp; struct xfs_buf *cbp; int level; int index; int numrecs; int error; #ifdef DEBUG union xfs_btree_ptr ptr; #endif int i; ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE); ASSERT(cur->bc_nlevels > 1); /* * Don't deal with the root block needs to be a leaf case. * We're just going to turn the thing back into extents anyway. */ level = cur->bc_nlevels - 1; if (level == 1) goto out0; /* * Give up if the root has multiple children. */ block = xfs_btree_get_iroot(cur); if (xfs_btree_get_numrecs(block) != 1) goto out0; cblock = xfs_btree_get_block(cur, level - 1, &cbp); numrecs = xfs_btree_get_numrecs(cblock); /* * Only do this if the next level will fit. * Then the data must be copied up to the inode, * instead of freeing the root you free the next level. */ if (numrecs > cur->bc_ops->get_dmaxrecs(cur, level)) goto out0; XFS_BTREE_STATS_INC(cur, killroot); #ifdef DEBUG xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB); ASSERT(xfs_btree_ptr_is_null(cur, &ptr)); xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB); ASSERT(xfs_btree_ptr_is_null(cur, &ptr)); #endif index = numrecs - cur->bc_ops->get_maxrecs(cur, level); if (index) { xfs_iroot_realloc(cur->bc_ino.ip, index, cur->bc_ino.whichfork); block = ifp->if_broot; } be16_add_cpu(&block->bb_numrecs, index); ASSERT(block->bb_numrecs == cblock->bb_numrecs); kp = xfs_btree_key_addr(cur, 1, block); ckp = xfs_btree_key_addr(cur, 1, cblock); xfs_btree_copy_keys(cur, kp, ckp, numrecs); pp = xfs_btree_ptr_addr(cur, 1, block); cpp = xfs_btree_ptr_addr(cur, 1, cblock); for (i = 0; i < numrecs; i++) { error = xfs_btree_debug_check_ptr(cur, cpp, i, level - 1); if (error) return error; } xfs_btree_copy_ptrs(cur, pp, cpp, numrecs); error = xfs_btree_free_block(cur, cbp); if (error) return error; cur->bc_levels[level - 1].bp = NULL; be16_add_cpu(&block->bb_level, -1); xfs_trans_log_inode(cur->bc_tp, ip, XFS_ILOG_CORE | xfs_ilog_fbroot(cur->bc_ino.whichfork)); cur->bc_nlevels--; out0: return 0; } /* * Kill the current root node, and replace it with it's only child node. */ STATIC int xfs_btree_kill_root( struct xfs_btree_cur *cur, struct xfs_buf *bp, int level, union xfs_btree_ptr *newroot) { int error; XFS_BTREE_STATS_INC(cur, killroot); /* * Update the root pointer, decreasing the level by 1 and then * free the old root. */ cur->bc_ops->set_root(cur, newroot, -1); error = xfs_btree_free_block(cur, bp); if (error) return error; cur->bc_levels[level].bp = NULL; cur->bc_levels[level].ra = 0; cur->bc_nlevels--; return 0; } STATIC int xfs_btree_dec_cursor( struct xfs_btree_cur *cur, int level, int *stat) { int error; int i; if (level > 0) { error = xfs_btree_decrement(cur, level, &i); if (error) return error; } *stat = 1; return 0; } /* * Single level of the btree record deletion routine. * Delete record pointed to by cur/level. * Remove the record from its block then rebalance the tree. * Return 0 for error, 1 for done, 2 to go on to the next level. */ STATIC int /* error */ xfs_btree_delrec( struct xfs_btree_cur *cur, /* btree cursor */ int level, /* level removing record from */ int *stat) /* fail/done/go-on */ { struct xfs_btree_block *block; /* btree block */ union xfs_btree_ptr cptr; /* current block ptr */ struct xfs_buf *bp; /* buffer for block */ int error; /* error return value */ int i; /* loop counter */ union xfs_btree_ptr lptr; /* left sibling block ptr */ struct xfs_buf *lbp; /* left buffer pointer */ struct xfs_btree_block *left; /* left btree block */ int lrecs = 0; /* left record count */ int ptr; /* key/record index */ union xfs_btree_ptr rptr; /* right sibling block ptr */ struct xfs_buf *rbp; /* right buffer pointer */ struct xfs_btree_block *right; /* right btree block */ struct xfs_btree_block *rrblock; /* right-right btree block */ struct xfs_buf *rrbp; /* right-right buffer pointer */ int rrecs = 0; /* right record count */ struct xfs_btree_cur *tcur; /* temporary btree cursor */ int numrecs; /* temporary numrec count */ tcur = NULL; /* Get the index of the entry being deleted, check for nothing there. */ ptr = cur->bc_levels[level].ptr; if (ptr == 0) { *stat = 0; return 0; } /* Get the buffer & block containing the record or key/ptr. */ block = xfs_btree_get_block(cur, level, &bp); numrecs = xfs_btree_get_numrecs(block); #ifdef DEBUG error = xfs_btree_check_block(cur, block, level, bp); if (error) goto error0; #endif /* Fail if we're off the end of the block. */ if (ptr > numrecs) { *stat = 0; return 0; } XFS_BTREE_STATS_INC(cur, delrec); XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr); /* Excise the entries being deleted. */ if (level > 0) { /* It's a nonleaf. operate on keys and ptrs */ union xfs_btree_key *lkp; union xfs_btree_ptr *lpp; lkp = xfs_btree_key_addr(cur, ptr + 1, block); lpp = xfs_btree_ptr_addr(cur, ptr + 1, block); for (i = 0; i < numrecs - ptr; i++) { error = xfs_btree_debug_check_ptr(cur, lpp, i, level); if (error) goto error0; } if (ptr < numrecs) { xfs_btree_shift_keys(cur, lkp, -1, numrecs - ptr); xfs_btree_shift_ptrs(cur, lpp, -1, numrecs - ptr); xfs_btree_log_keys(cur, bp, ptr, numrecs - 1); xfs_btree_log_ptrs(cur, bp, ptr, numrecs - 1); } } else { /* It's a leaf. operate on records */ if (ptr < numrecs) { xfs_btree_shift_recs(cur, xfs_btree_rec_addr(cur, ptr + 1, block), -1, numrecs - ptr); xfs_btree_log_recs(cur, bp, ptr, numrecs - 1); } } /* * Decrement and log the number of entries in the block. */ xfs_btree_set_numrecs(block, --numrecs); xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS); /* * If we are tracking the last record in the tree and * we are at the far right edge of the tree, update it. */ if (xfs_btree_is_lastrec(cur, block, level)) { cur->bc_ops->update_lastrec(cur, block, NULL, ptr, LASTREC_DELREC); } /* * We're at the root level. First, shrink the root block in-memory. * Try to get rid of the next level down. If we can't then there's * nothing left to do. */ if (level == cur->bc_nlevels - 1) { if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) { xfs_iroot_realloc(cur->bc_ino.ip, -1, cur->bc_ino.whichfork); error = xfs_btree_kill_iroot(cur); if (error) goto error0; error = xfs_btree_dec_cursor(cur, level, stat); if (error) goto error0; *stat = 1; return 0; } /* * If this is the root level, and there's only one entry left, * and it's NOT the leaf level, then we can get rid of this * level. */ if (numrecs == 1 && level > 0) { union xfs_btree_ptr *pp; /* * pp is still set to the first pointer in the block. * Make it the new root of the btree. */ pp = xfs_btree_ptr_addr(cur, 1, block); error = xfs_btree_kill_root(cur, bp, level, pp); if (error) goto error0; } else if (level > 0) { error = xfs_btree_dec_cursor(cur, level, stat); if (error) goto error0; } *stat = 1; return 0; } /* * If we deleted the leftmost entry in the block, update the * key values above us in the tree. */ if (xfs_btree_needs_key_update(cur, ptr)) { error = xfs_btree_update_keys(cur, level); if (error) goto error0; } /* * If the number of records remaining in the block is at least * the minimum, we're done. */ if (numrecs >= cur->bc_ops->get_minrecs(cur, level)) { error = xfs_btree_dec_cursor(cur, level, stat); if (error) goto error0; return 0; } /* * Otherwise, we have to move some records around to keep the * tree balanced. Look at the left and right sibling blocks to * see if we can re-balance by moving only one record. */ xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB); xfs_btree_get_sibling(cur, block, &lptr, XFS_BB_LEFTSIB); if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) { /* * One child of root, need to get a chance to copy its contents * into the root and delete it. Can't go up to next level, * there's nothing to delete there. */ if (xfs_btree_ptr_is_null(cur, &rptr) && xfs_btree_ptr_is_null(cur, &lptr) && level == cur->bc_nlevels - 2) { error = xfs_btree_kill_iroot(cur); if (!error) error = xfs_btree_dec_cursor(cur, level, stat); if (error) goto error0; return 0; } } ASSERT(!xfs_btree_ptr_is_null(cur, &rptr) || !xfs_btree_ptr_is_null(cur, &lptr)); /* * Duplicate the cursor so our btree manipulations here won't * disrupt the next level up. */ error = xfs_btree_dup_cursor(cur, &tcur); if (error) goto error0; /* * If there's a right sibling, see if it's ok to shift an entry * out of it. */ if (!xfs_btree_ptr_is_null(cur, &rptr)) { /* * Move the temp cursor to the last entry in the next block. * Actually any entry but the first would suffice. */ i = xfs_btree_lastrec(tcur, level); if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) { error = -EFSCORRUPTED; goto error0; } error = xfs_btree_increment(tcur, level, &i); if (error) goto error0; if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) { error = -EFSCORRUPTED; goto error0; } i = xfs_btree_lastrec(tcur, level); if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) { error = -EFSCORRUPTED; goto error0; } /* Grab a pointer to the block. */ right = xfs_btree_get_block(tcur, level, &rbp); #ifdef DEBUG error = xfs_btree_check_block(tcur, right, level, rbp); if (error) goto error0; #endif /* Grab the current block number, for future use. */ xfs_btree_get_sibling(tcur, right, &cptr, XFS_BB_LEFTSIB); /* * If right block is full enough so that removing one entry * won't make it too empty, and left-shifting an entry out * of right to us works, we're done. */ if (xfs_btree_get_numrecs(right) - 1 >= cur->bc_ops->get_minrecs(tcur, level)) { error = xfs_btree_lshift(tcur, level, &i); if (error) goto error0; if (i) { ASSERT(xfs_btree_get_numrecs(block) >= cur->bc_ops->get_minrecs(tcur, level)); xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR); tcur = NULL; error = xfs_btree_dec_cursor(cur, level, stat); if (error) goto error0; return 0; } } /* * Otherwise, grab the number of records in right for * future reference, and fix up the temp cursor to point * to our block again (last record). */ rrecs = xfs_btree_get_numrecs(right); if (!xfs_btree_ptr_is_null(cur, &lptr)) { i = xfs_btree_firstrec(tcur, level); if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) { error = -EFSCORRUPTED; goto error0; } error = xfs_btree_decrement(tcur, level, &i); if (error) goto error0; if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) { error = -EFSCORRUPTED; goto error0; } } } /* * If there's a left sibling, see if it's ok to shift an entry * out of it. */ if (!xfs_btree_ptr_is_null(cur, &lptr)) { /* * Move the temp cursor to the first entry in the * previous block. */ i = xfs_btree_firstrec(tcur, level); if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) { error = -EFSCORRUPTED; goto error0; } error = xfs_btree_decrement(tcur, level, &i); if (error) goto error0; i = xfs_btree_firstrec(tcur, level); if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) { error = -EFSCORRUPTED; goto error0; } /* Grab a pointer to the block. */ left = xfs_btree_get_block(tcur, level, &lbp); #ifdef DEBUG error = xfs_btree_check_block(cur, left, level, lbp); if (error) goto error0; #endif /* Grab the current block number, for future use. */ xfs_btree_get_sibling(tcur, left, &cptr, XFS_BB_RIGHTSIB); /* * If left block is full enough so that removing one entry * won't make it too empty, and right-shifting an entry out * of left to us works, we're done. */ if (xfs_btree_get_numrecs(left) - 1 >= cur->bc_ops->get_minrecs(tcur, level)) { error = xfs_btree_rshift(tcur, level, &i); if (error) goto error0; if (i) { ASSERT(xfs_btree_get_numrecs(block) >= cur->bc_ops->get_minrecs(tcur, level)); xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR); tcur = NULL; if (level == 0) cur->bc_levels[0].ptr++; *stat = 1; return 0; } } /* * Otherwise, grab the number of records in right for * future reference. */ lrecs = xfs_btree_get_numrecs(left); } /* Delete the temp cursor, we're done with it. */ xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR); tcur = NULL; /* If here, we need to do a join to keep the tree balanced. */ ASSERT(!xfs_btree_ptr_is_null(cur, &cptr)); if (!xfs_btree_ptr_is_null(cur, &lptr) && lrecs + xfs_btree_get_numrecs(block) <= cur->bc_ops->get_maxrecs(cur, level)) { /* * Set "right" to be the starting block, * "left" to be the left neighbor. */ rptr = cptr; right = block; rbp = bp; error = xfs_btree_read_buf_block(cur, &lptr, 0, &left, &lbp); if (error) goto error0; /* * If that won't work, see if we can join with the right neighbor block. */ } else if (!xfs_btree_ptr_is_null(cur, &rptr) && rrecs + xfs_btree_get_numrecs(block) <= cur->bc_ops->get_maxrecs(cur, level)) { /* * Set "left" to be the starting block, * "right" to be the right neighbor. */ lptr = cptr; left = block; lbp = bp; error = xfs_btree_read_buf_block(cur, &rptr, 0, &right, &rbp); if (error) goto error0; /* * Otherwise, we can't fix the imbalance. * Just return. This is probably a logic error, but it's not fatal. */ } else { error = xfs_btree_dec_cursor(cur, level, stat); if (error) goto error0; return 0; } rrecs = xfs_btree_get_numrecs(right); lrecs = xfs_btree_get_numrecs(left); /* * We're now going to join "left" and "right" by moving all the stuff * in "right" to "left" and deleting "right". */ XFS_BTREE_STATS_ADD(cur, moves, rrecs); if (level > 0) { /* It's a non-leaf. Move keys and pointers. */ union xfs_btree_key *lkp; /* left btree key */ union xfs_btree_ptr *lpp; /* left address pointer */ union xfs_btree_key *rkp; /* right btree key */ union xfs_btree_ptr *rpp; /* right address pointer */ lkp = xfs_btree_key_addr(cur, lrecs + 1, left); lpp = xfs_btree_ptr_addr(cur, lrecs + 1, left); rkp = xfs_btree_key_addr(cur, 1, right); rpp = xfs_btree_ptr_addr(cur, 1, right); for (i = 1; i < rrecs; i++) { error = xfs_btree_debug_check_ptr(cur, rpp, i, level); if (error) goto error0; } xfs_btree_copy_keys(cur, lkp, rkp, rrecs); xfs_btree_copy_ptrs(cur, lpp, rpp, rrecs); xfs_btree_log_keys(cur, lbp, lrecs + 1, lrecs + rrecs); xfs_btree_log_ptrs(cur, lbp, lrecs + 1, lrecs + rrecs); } else { /* It's a leaf. Move records. */ union xfs_btree_rec *lrp; /* left record pointer */ union xfs_btree_rec *rrp; /* right record pointer */ lrp = xfs_btree_rec_addr(cur, lrecs + 1, left); rrp = xfs_btree_rec_addr(cur, 1, right); xfs_btree_copy_recs(cur, lrp, rrp, rrecs); xfs_btree_log_recs(cur, lbp, lrecs + 1, lrecs + rrecs); } XFS_BTREE_STATS_INC(cur, join); /* * Fix up the number of records and right block pointer in the * surviving block, and log it. */ xfs_btree_set_numrecs(left, lrecs + rrecs); xfs_btree_get_sibling(cur, right, &cptr, XFS_BB_RIGHTSIB); xfs_btree_set_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB); xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB); /* If there is a right sibling, point it to the remaining block. */ xfs_btree_get_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB); if (!xfs_btree_ptr_is_null(cur, &cptr)) { error = xfs_btree_read_buf_block(cur, &cptr, 0, &rrblock, &rrbp); if (error) goto error0; xfs_btree_set_sibling(cur, rrblock, &lptr, XFS_BB_LEFTSIB); xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB); } /* Free the deleted block. */ error = xfs_btree_free_block(cur, rbp); if (error) goto error0; /* * If we joined with the left neighbor, set the buffer in the * cursor to the left block, and fix up the index. */ if (bp != lbp) { cur->bc_levels[level].bp = lbp; cur->bc_levels[level].ptr += lrecs; cur->bc_levels[level].ra = 0; } /* * If we joined with the right neighbor and there's a level above * us, increment the cursor at that level. */ else if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) || (level + 1 < cur->bc_nlevels)) { error = xfs_btree_increment(cur, level + 1, &i); if (error) goto error0; } /* * Readjust the ptr at this level if it's not a leaf, since it's * still pointing at the deletion point, which makes the cursor * inconsistent. If this makes the ptr 0, the caller fixes it up. * We can't use decrement because it would change the next level up. */ if (level > 0) cur->bc_levels[level].ptr--; /* * We combined blocks, so we have to update the parent keys if the * btree supports overlapped intervals. However, * bc_levels[level + 1].ptr points to the old block so that the caller * knows which record to delete. Therefore, the caller must be savvy * enough to call updkeys for us if we return stat == 2. The other * exit points from this function don't require deletions further up * the tree, so they can call updkeys directly. */ /* Return value means the next level up has something to do. */ *stat = 2; return 0; error0: if (tcur) xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR); return error; } /* * Delete the record pointed to by cur. * The cursor refers to the place where the record was (could be inserted) * when the operation returns. */ int /* error */ xfs_btree_delete( struct xfs_btree_cur *cur, int *stat) /* success/failure */ { int error; /* error return value */ int level; int i; bool joined = false; /* * Go up the tree, starting at leaf level. * * If 2 is returned then a join was done; go to the next level. * Otherwise we are done. */ for (level = 0, i = 2; i == 2; level++) { error = xfs_btree_delrec(cur, level, &i); if (error) goto error0; if (i == 2) joined = true; } /* * If we combined blocks as part of deleting the record, delrec won't * have updated the parent high keys so we have to do that here. */ if (joined && (cur->bc_flags & XFS_BTREE_OVERLAPPING)) { error = xfs_btree_updkeys_force(cur, 0); if (error) goto error0; } if (i == 0) { for (level = 1; level < cur->bc_nlevels; level++) { if (cur->bc_levels[level].ptr == 0) { error = xfs_btree_decrement(cur, level, &i); if (error) goto error0; break; } } } *stat = i; return 0; error0: return error; } /* * Get the data from the pointed-to record. */ int /* error */ xfs_btree_get_rec( struct xfs_btree_cur *cur, /* btree cursor */ union xfs_btree_rec **recp, /* output: btree record */ int *stat) /* output: success/failure */ { struct xfs_btree_block *block; /* btree block */ struct xfs_buf *bp; /* buffer pointer */ int ptr; /* record number */ #ifdef DEBUG int error; /* error return value */ #endif ptr = cur->bc_levels[0].ptr; block = xfs_btree_get_block(cur, 0, &bp); #ifdef DEBUG error = xfs_btree_check_block(cur, block, 0, bp); if (error) return error; #endif /* * Off the right end or left end, return failure. */ if (ptr > xfs_btree_get_numrecs(block) || ptr <= 0) { *stat = 0; return 0; } /* * Point to the record and extract its data. */ *recp = xfs_btree_rec_addr(cur, ptr, block); *stat = 1; return 0; } /* Visit a block in a btree. */ STATIC int xfs_btree_visit_block( struct xfs_btree_cur *cur, int level, xfs_btree_visit_blocks_fn fn, void *data) { struct xfs_btree_block *block; struct xfs_buf *bp; union xfs_btree_ptr rptr; int error; /* do right sibling readahead */ xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA); block = xfs_btree_get_block(cur, level, &bp); /* process the block */ error = fn(cur, level, data); if (error) return error; /* now read rh sibling block for next iteration */ xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB); if (xfs_btree_ptr_is_null(cur, &rptr)) return -ENOENT; /* * We only visit blocks once in this walk, so we have to avoid the * internal xfs_btree_lookup_get_block() optimisation where it will * return the same block without checking if the right sibling points * back to us and creates a cyclic reference in the btree. */ if (cur->bc_flags & XFS_BTREE_LONG_PTRS) { if (be64_to_cpu(rptr.l) == XFS_DADDR_TO_FSB(cur->bc_mp, xfs_buf_daddr(bp))) return -EFSCORRUPTED; } else { if (be32_to_cpu(rptr.s) == xfs_daddr_to_agbno(cur->bc_mp, xfs_buf_daddr(bp))) return -EFSCORRUPTED; } return xfs_btree_lookup_get_block(cur, level, &rptr, &block); } /* Visit every block in a btree. */ int xfs_btree_visit_blocks( struct xfs_btree_cur *cur, xfs_btree_visit_blocks_fn fn, unsigned int flags, void *data) { union xfs_btree_ptr lptr; int level; struct xfs_btree_block *block = NULL; int error = 0; cur->bc_ops->init_ptr_from_cur(cur, &lptr); /* for each level */ for (level = cur->bc_nlevels - 1; level >= 0; level--) { /* grab the left hand block */ error = xfs_btree_lookup_get_block(cur, level, &lptr, &block); if (error) return error; /* readahead the left most block for the next level down */ if (level > 0) { union xfs_btree_ptr *ptr; ptr = xfs_btree_ptr_addr(cur, 1, block); xfs_btree_readahead_ptr(cur, ptr, 1); /* save for the next iteration of the loop */ xfs_btree_copy_ptrs(cur, &lptr, ptr, 1); if (!(flags & XFS_BTREE_VISIT_LEAVES)) continue; } else if (!(flags & XFS_BTREE_VISIT_RECORDS)) { continue; } /* for each buffer in the level */ do { error = xfs_btree_visit_block(cur, level, fn, data); } while (!error); if (error != -ENOENT) return error; } return 0; } /* * Change the owner of a btree. * * The mechanism we use here is ordered buffer logging. Because we don't know * how many buffers were are going to need to modify, we don't really want to * have to make transaction reservations for the worst case of every buffer in a * full size btree as that may be more space that we can fit in the log.... * * We do the btree walk in the most optimal manner possible - we have sibling * pointers so we can just walk all the blocks on each level from left to right * in a single pass, and then move to the next level and do the same. We can * also do readahead on the sibling pointers to get IO moving more quickly, * though for slow disks this is unlikely to make much difference to performance * as the amount of CPU work we have to do before moving to the next block is * relatively small. * * For each btree block that we load, modify the owner appropriately, set the * buffer as an ordered buffer and log it appropriately. We need to ensure that * we mark the region we change dirty so that if the buffer is relogged in * a subsequent transaction the changes we make here as an ordered buffer are * correctly relogged in that transaction. If we are in recovery context, then * just queue the modified buffer as delayed write buffer so the transaction * recovery completion writes the changes to disk. */ struct xfs_btree_block_change_owner_info { uint64_t new_owner; struct list_head *buffer_list; }; static int xfs_btree_block_change_owner( struct xfs_btree_cur *cur, int level, void *data) { struct xfs_btree_block_change_owner_info *bbcoi = data; struct xfs_btree_block *block; struct xfs_buf *bp; /* modify the owner */ block = xfs_btree_get_block(cur, level, &bp); if (cur->bc_flags & XFS_BTREE_LONG_PTRS) { if (block->bb_u.l.bb_owner == cpu_to_be64(bbcoi->new_owner)) return 0; block->bb_u.l.bb_owner = cpu_to_be64(bbcoi->new_owner); } else { if (block->bb_u.s.bb_owner == cpu_to_be32(bbcoi->new_owner)) return 0; block->bb_u.s.bb_owner = cpu_to_be32(bbcoi->new_owner); } /* * If the block is a root block hosted in an inode, we might not have a * buffer pointer here and we shouldn't attempt to log the change as the * information is already held in the inode and discarded when the root * block is formatted into the on-disk inode fork. We still change it, * though, so everything is consistent in memory. */ if (!bp) { ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE); ASSERT(level == cur->bc_nlevels - 1); return 0; } if (cur->bc_tp) { if (!xfs_trans_ordered_buf(cur->bc_tp, bp)) { xfs_btree_log_block(cur, bp, XFS_BB_OWNER); return -EAGAIN; } } else { xfs_buf_delwri_queue(bp, bbcoi->buffer_list); } return 0; } int xfs_btree_change_owner( struct xfs_btree_cur *cur, uint64_t new_owner, struct list_head *buffer_list) { struct xfs_btree_block_change_owner_info bbcoi; bbcoi.new_owner = new_owner; bbcoi.buffer_list = buffer_list; return xfs_btree_visit_blocks(cur, xfs_btree_block_change_owner, XFS_BTREE_VISIT_ALL, &bbcoi); } /* Verify the v5 fields of a long-format btree block. */ xfs_failaddr_t xfs_btree_lblock_v5hdr_verify( struct xfs_buf *bp, uint64_t owner) { struct xfs_mount *mp = bp->b_mount; struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp); if (!xfs_has_crc(mp)) return __this_address; if (!uuid_equal(&block->bb_u.l.bb_uuid, &mp->m_sb.sb_meta_uuid)) return __this_address; if (block->bb_u.l.bb_blkno != cpu_to_be64(xfs_buf_daddr(bp))) return __this_address; if (owner != XFS_RMAP_OWN_UNKNOWN && be64_to_cpu(block->bb_u.l.bb_owner) != owner) return __this_address; return NULL; } /* Verify a long-format btree block. */ xfs_failaddr_t xfs_btree_lblock_verify( struct xfs_buf *bp, unsigned int max_recs) { struct xfs_mount *mp = bp->b_mount; struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp); xfs_fsblock_t fsb; xfs_failaddr_t fa; /* numrecs verification */ if (be16_to_cpu(block->bb_numrecs) > max_recs) return __this_address; /* sibling pointer verification */ fsb = XFS_DADDR_TO_FSB(mp, xfs_buf_daddr(bp)); fa = xfs_btree_check_lblock_siblings(mp, NULL, -1, fsb, block->bb_u.l.bb_leftsib); if (!fa) fa = xfs_btree_check_lblock_siblings(mp, NULL, -1, fsb, block->bb_u.l.bb_rightsib); return fa; } /** * xfs_btree_sblock_v5hdr_verify() -- verify the v5 fields of a short-format * btree block * * @bp: buffer containing the btree block */ xfs_failaddr_t xfs_btree_sblock_v5hdr_verify( struct xfs_buf *bp) { struct xfs_mount *mp = bp->b_mount; struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp); struct xfs_perag *pag = bp->b_pag; if (!xfs_has_crc(mp)) return __this_address; if (!uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid)) return __this_address; if (block->bb_u.s.bb_blkno != cpu_to_be64(xfs_buf_daddr(bp))) return __this_address; if (pag && be32_to_cpu(block->bb_u.s.bb_owner) != pag->pag_agno) return __this_address; return NULL; } /** * xfs_btree_sblock_verify() -- verify a short-format btree block * * @bp: buffer containing the btree block * @max_recs: maximum records allowed in this btree node */ xfs_failaddr_t xfs_btree_sblock_verify( struct xfs_buf *bp, unsigned int max_recs) { struct xfs_mount *mp = bp->b_mount; struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp); xfs_agblock_t agbno; xfs_failaddr_t fa; /* numrecs verification */ if (be16_to_cpu(block->bb_numrecs) > max_recs) return __this_address; /* sibling pointer verification */ agbno = xfs_daddr_to_agbno(mp, xfs_buf_daddr(bp)); fa = xfs_btree_check_sblock_siblings(bp->b_pag, NULL, -1, agbno, block->bb_u.s.bb_leftsib); if (!fa) fa = xfs_btree_check_sblock_siblings(bp->b_pag, NULL, -1, agbno, block->bb_u.s.bb_rightsib); return fa; } /* * For the given limits on leaf and keyptr records per block, calculate the * height of the tree needed to index the number of leaf records. */ unsigned int xfs_btree_compute_maxlevels( const unsigned int *limits, unsigned long long records) { unsigned long long level_blocks = howmany_64(records, limits[0]); unsigned int height = 1; while (level_blocks > 1) { level_blocks = howmany_64(level_blocks, limits[1]); height++; } return height; } /* * For the given limits on leaf and keyptr records per block, calculate the * number of blocks needed to index the given number of leaf records. */ unsigned long long xfs_btree_calc_size( const unsigned int *limits, unsigned long long records) { unsigned long long level_blocks = howmany_64(records, limits[0]); unsigned long long blocks = level_blocks; while (level_blocks > 1) { level_blocks = howmany_64(level_blocks, limits[1]); blocks += level_blocks; } return blocks; } /* * Given a number of available blocks for the btree to consume with records and * pointers, calculate the height of the tree needed to index all the records * that space can hold based on the number of pointers each interior node * holds. * * We start by assuming a single level tree consumes a single block, then track * the number of blocks each node level consumes until we no longer have space * to store the next node level. At this point, we are indexing all the leaf * blocks in the space, and there's no more free space to split the tree any * further. That's our maximum btree height. */ unsigned int xfs_btree_space_to_height( const unsigned int *limits, unsigned long long leaf_blocks) { /* * The root btree block can have fewer than minrecs pointers in it * because the tree might not be big enough to require that amount of * fanout. Hence it has a minimum size of 2 pointers, not limits[1]. */ unsigned long long node_blocks = 2; unsigned long long blocks_left = leaf_blocks - 1; unsigned int height = 1; if (leaf_blocks < 1) return 0; while (node_blocks < blocks_left) { blocks_left -= node_blocks; node_blocks *= limits[1]; height++; } return height; } /* * Query a regular btree for all records overlapping a given interval. * Start with a LE lookup of the key of low_rec and return all records * until we find a record with a key greater than the key of high_rec. */ STATIC int xfs_btree_simple_query_range( struct xfs_btree_cur *cur, const union xfs_btree_key *low_key, const union xfs_btree_key *high_key, xfs_btree_query_range_fn fn, void *priv) { union xfs_btree_rec *recp; union xfs_btree_key rec_key; int stat; bool firstrec = true; int error; ASSERT(cur->bc_ops->init_high_key_from_rec); ASSERT(cur->bc_ops->diff_two_keys); /* * Find the leftmost record. The btree cursor must be set * to the low record used to generate low_key. */ stat = 0; error = xfs_btree_lookup(cur, XFS_LOOKUP_LE, &stat); if (error) goto out; /* Nothing? See if there's anything to the right. */ if (!stat) { error = xfs_btree_increment(cur, 0, &stat); if (error) goto out; } while (stat) { /* Find the record. */ error = xfs_btree_get_rec(cur, &recp, &stat); if (error || !stat) break; /* Skip if low_key > high_key(rec). */ if (firstrec) { cur->bc_ops->init_high_key_from_rec(&rec_key, recp); firstrec = false; if (xfs_btree_keycmp_gt(cur, low_key, &rec_key)) goto advloop; } /* Stop if low_key(rec) > high_key. */ cur->bc_ops->init_key_from_rec(&rec_key, recp); if (xfs_btree_keycmp_gt(cur, &rec_key, high_key)) break; /* Callback */ error = fn(cur, recp, priv); if (error) break; advloop: /* Move on to the next record. */ error = xfs_btree_increment(cur, 0, &stat); if (error) break; } out: return error; } /* * Query an overlapped interval btree for all records overlapping a given * interval. This function roughly follows the algorithm given in * "Interval Trees" of _Introduction to Algorithms_, which is section * 14.3 in the 2nd and 3rd editions. * * First, generate keys for the low and high records passed in. * * For any leaf node, generate the high and low keys for the record. * If the record keys overlap with the query low/high keys, pass the * record to the function iterator. * * For any internal node, compare the low and high keys of each * pointer against the query low/high keys. If there's an overlap, * follow the pointer. * * As an optimization, we stop scanning a block when we find a low key * that is greater than the query's high key. */ STATIC int xfs_btree_overlapped_query_range( struct xfs_btree_cur *cur, const union xfs_btree_key *low_key, const union xfs_btree_key *high_key, xfs_btree_query_range_fn fn, void *priv) { union xfs_btree_ptr ptr; union xfs_btree_ptr *pp; union xfs_btree_key rec_key; union xfs_btree_key rec_hkey; union xfs_btree_key *lkp; union xfs_btree_key *hkp; union xfs_btree_rec *recp; struct xfs_btree_block *block; int level; struct xfs_buf *bp; int i; int error; /* Load the root of the btree. */ level = cur->bc_nlevels - 1; cur->bc_ops->init_ptr_from_cur(cur, &ptr); error = xfs_btree_lookup_get_block(cur, level, &ptr, &block); if (error) return error; xfs_btree_get_block(cur, level, &bp); trace_xfs_btree_overlapped_query_range(cur, level, bp); #ifdef DEBUG error = xfs_btree_check_block(cur, block, level, bp); if (error) goto out; #endif cur->bc_levels[level].ptr = 1; while (level < cur->bc_nlevels) { block = xfs_btree_get_block(cur, level, &bp); /* End of node, pop back towards the root. */ if (cur->bc_levels[level].ptr > be16_to_cpu(block->bb_numrecs)) { pop_up: if (level < cur->bc_nlevels - 1) cur->bc_levels[level + 1].ptr++; level++; continue; } if (level == 0) { /* Handle a leaf node. */ recp = xfs_btree_rec_addr(cur, cur->bc_levels[0].ptr, block); cur->bc_ops->init_high_key_from_rec(&rec_hkey, recp); cur->bc_ops->init_key_from_rec(&rec_key, recp); /* * If (query's high key < record's low key), then there * are no more interesting records in this block. Pop * up to the leaf level to find more record blocks. * * If (record's high key >= query's low key) and * (query's high key >= record's low key), then * this record overlaps the query range; callback. */ if (xfs_btree_keycmp_lt(cur, high_key, &rec_key)) goto pop_up; if (xfs_btree_keycmp_ge(cur, &rec_hkey, low_key)) { error = fn(cur, recp, priv); if (error) break; } cur->bc_levels[level].ptr++; continue; } /* Handle an internal node. */ lkp = xfs_btree_key_addr(cur, cur->bc_levels[level].ptr, block); hkp = xfs_btree_high_key_addr(cur, cur->bc_levels[level].ptr, block); pp = xfs_btree_ptr_addr(cur, cur->bc_levels[level].ptr, block); /* * If (query's high key < pointer's low key), then there are no * more interesting keys in this block. Pop up one leaf level * to continue looking for records. * * If (pointer's high key >= query's low key) and * (query's high key >= pointer's low key), then * this record overlaps the query range; follow pointer. */ if (xfs_btree_keycmp_lt(cur, high_key, lkp)) goto pop_up; if (xfs_btree_keycmp_ge(cur, hkp, low_key)) { level--; error = xfs_btree_lookup_get_block(cur, level, pp, &block); if (error) goto out; xfs_btree_get_block(cur, level, &bp); trace_xfs_btree_overlapped_query_range(cur, level, bp); #ifdef DEBUG error = xfs_btree_check_block(cur, block, level, bp); if (error) goto out; #endif cur->bc_levels[level].ptr = 1; continue; } cur->bc_levels[level].ptr++; } out: /* * If we don't end this function with the cursor pointing at a record * block, a subsequent non-error cursor deletion will not release * node-level buffers, causing a buffer leak. This is quite possible * with a zero-results range query, so release the buffers if we * failed to return any results. */ if (cur->bc_levels[0].bp == NULL) { for (i = 0; i < cur->bc_nlevels; i++) { if (cur->bc_levels[i].bp) { xfs_trans_brelse(cur->bc_tp, cur->bc_levels[i].bp); cur->bc_levels[i].bp = NULL; cur->bc_levels[i].ptr = 0; cur->bc_levels[i].ra = 0; } } } return error; } static inline void xfs_btree_key_from_irec( struct xfs_btree_cur *cur, union xfs_btree_key *key, const union xfs_btree_irec *irec) { union xfs_btree_rec rec; cur->bc_rec = *irec; cur->bc_ops->init_rec_from_cur(cur, &rec); cur->bc_ops->init_key_from_rec(key, &rec); } /* * Query a btree for all records overlapping a given interval of keys. The * supplied function will be called with each record found; return one of the * XFS_BTREE_QUERY_RANGE_{CONTINUE,ABORT} values or the usual negative error * code. This function returns -ECANCELED, zero, or a negative error code. */ int xfs_btree_query_range( struct xfs_btree_cur *cur, const union xfs_btree_irec *low_rec, const union xfs_btree_irec *high_rec, xfs_btree_query_range_fn fn, void *priv) { union xfs_btree_key low_key; union xfs_btree_key high_key; /* Find the keys of both ends of the interval. */ xfs_btree_key_from_irec(cur, &high_key, high_rec); xfs_btree_key_from_irec(cur, &low_key, low_rec); /* Enforce low key <= high key. */ if (!xfs_btree_keycmp_le(cur, &low_key, &high_key)) return -EINVAL; if (!(cur->bc_flags & XFS_BTREE_OVERLAPPING)) return xfs_btree_simple_query_range(cur, &low_key, &high_key, fn, priv); return xfs_btree_overlapped_query_range(cur, &low_key, &high_key, fn, priv); } /* Query a btree for all records. */ int xfs_btree_query_all( struct xfs_btree_cur *cur, xfs_btree_query_range_fn fn, void *priv) { union xfs_btree_key low_key; union xfs_btree_key high_key; memset(&cur->bc_rec, 0, sizeof(cur->bc_rec)); memset(&low_key, 0, sizeof(low_key)); memset(&high_key, 0xFF, sizeof(high_key)); return xfs_btree_simple_query_range(cur, &low_key, &high_key, fn, priv); } static int xfs_btree_count_blocks_helper( struct xfs_btree_cur *cur, int level, void *data) { xfs_extlen_t *blocks = data; (*blocks)++; return 0; } /* Count the blocks in a btree and return the result in *blocks. */ int xfs_btree_count_blocks( struct xfs_btree_cur *cur, xfs_extlen_t *blocks) { *blocks = 0; return xfs_btree_visit_blocks(cur, xfs_btree_count_blocks_helper, XFS_BTREE_VISIT_ALL, blocks); } /* Compare two btree pointers. */ int64_t xfs_btree_diff_two_ptrs( struct xfs_btree_cur *cur, const union xfs_btree_ptr *a, const union xfs_btree_ptr *b) { if (cur->bc_flags & XFS_BTREE_LONG_PTRS) return (int64_t)be64_to_cpu(a->l) - be64_to_cpu(b->l); return (int64_t)be32_to_cpu(a->s) - be32_to_cpu(b->s); } struct xfs_btree_has_records { /* Keys for the start and end of the range we want to know about. */ union xfs_btree_key start_key; union xfs_btree_key end_key; /* Mask for key comparisons, if desired. */ const union xfs_btree_key *key_mask; /* Highest record key we've seen so far. */ union xfs_btree_key high_key; enum xbtree_recpacking outcome; }; STATIC int xfs_btree_has_records_helper( struct xfs_btree_cur *cur, const union xfs_btree_rec *rec, void *priv) { union xfs_btree_key rec_key; union xfs_btree_key rec_high_key; struct xfs_btree_has_records *info = priv; enum xbtree_key_contig key_contig; cur->bc_ops->init_key_from_rec(&rec_key, rec); if (info->outcome == XBTREE_RECPACKING_EMPTY) { info->outcome = XBTREE_RECPACKING_SPARSE; /* * If the first record we find does not overlap the start key, * then there is a hole at the start of the search range. * Classify this as sparse and stop immediately. */ if (xfs_btree_masked_keycmp_lt(cur, &info->start_key, &rec_key, info->key_mask)) return -ECANCELED; } else { /* * If a subsequent record does not overlap with the any record * we've seen so far, there is a hole in the middle of the * search range. Classify this as sparse and stop. * If the keys overlap and this btree does not allow overlap, * signal corruption. */ key_contig = cur->bc_ops->keys_contiguous(cur, &info->high_key, &rec_key, info->key_mask); if (key_contig == XBTREE_KEY_OVERLAP && !(cur->bc_flags & XFS_BTREE_OVERLAPPING)) return -EFSCORRUPTED; if (key_contig == XBTREE_KEY_GAP) return -ECANCELED; } /* * If high_key(rec) is larger than any other high key we've seen, * remember it for later. */ cur->bc_ops->init_high_key_from_rec(&rec_high_key, rec); if (xfs_btree_masked_keycmp_gt(cur, &rec_high_key, &info->high_key, info->key_mask)) info->high_key = rec_high_key; /* struct copy */ return 0; } /* * Scan part of the keyspace of a btree and tell us if that keyspace does not * map to any records; is fully mapped to records; or is partially mapped to * records. This is the btree record equivalent to determining if a file is * sparse. * * For most btree types, the record scan should use all available btree key * fields to compare the keys encountered. These callers should pass NULL for * @mask. However, some callers (e.g. scanning physical space in the rmapbt) * want to ignore some part of the btree record keyspace when performing the * comparison. These callers should pass in a union xfs_btree_key object with * the fields that *should* be a part of the comparison set to any nonzero * value, and the rest zeroed. */ int xfs_btree_has_records( struct xfs_btree_cur *cur, const union xfs_btree_irec *low, const union xfs_btree_irec *high, const union xfs_btree_key *mask, enum xbtree_recpacking *outcome) { struct xfs_btree_has_records info = { .outcome = XBTREE_RECPACKING_EMPTY, .key_mask = mask, }; int error; /* Not all btrees support this operation. */ if (!cur->bc_ops->keys_contiguous) { ASSERT(0); return -EOPNOTSUPP; } xfs_btree_key_from_irec(cur, &info.start_key, low); xfs_btree_key_from_irec(cur, &info.end_key, high); error = xfs_btree_query_range(cur, low, high, xfs_btree_has_records_helper, &info); if (error == -ECANCELED) goto out; if (error) return error; if (info.outcome == XBTREE_RECPACKING_EMPTY) goto out; /* * If the largest high_key(rec) we saw during the walk is greater than * the end of the search range, classify this as full. Otherwise, * there is a hole at the end of the search range. */ if (xfs_btree_masked_keycmp_ge(cur, &info.high_key, &info.end_key, mask)) info.outcome = XBTREE_RECPACKING_FULL; out: *outcome = info.outcome; return 0; } /* Are there more records in this btree? */ bool xfs_btree_has_more_records( struct xfs_btree_cur *cur) { struct xfs_btree_block *block; struct xfs_buf *bp; block = xfs_btree_get_block(cur, 0, &bp); /* There are still records in this block. */ if (cur->bc_levels[0].ptr < xfs_btree_get_numrecs(block)) return true; /* There are more record blocks. */ if (cur->bc_flags & XFS_BTREE_LONG_PTRS) return block->bb_u.l.bb_rightsib != cpu_to_be64(NULLFSBLOCK); else return block->bb_u.s.bb_rightsib != cpu_to_be32(NULLAGBLOCK); } /* Set up all the btree cursor caches. */ int __init xfs_btree_init_cur_caches(void) { int error; error = xfs_allocbt_init_cur_cache(); if (error) return error; error = xfs_inobt_init_cur_cache(); if (error) goto err; error = xfs_bmbt_init_cur_cache(); if (error) goto err; error = xfs_rmapbt_init_cur_cache(); if (error) goto err; error = xfs_refcountbt_init_cur_cache(); if (error) goto err; return 0; err: xfs_btree_destroy_cur_caches(); return error; } /* Destroy all the btree cursor caches, if they've been allocated. */ void xfs_btree_destroy_cur_caches(void) { xfs_allocbt_destroy_cur_cache(); xfs_inobt_destroy_cur_cache(); xfs_bmbt_destroy_cur_cache(); xfs_rmapbt_destroy_cur_cache(); xfs_refcountbt_destroy_cur_cache(); }
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