diff options
Diffstat (limited to 'fs/xfs/libxfs/xfs_btree.c')
| -rw-r--r-- | fs/xfs/libxfs/xfs_btree.c | 5099 |
1 files changed, 5099 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c new file mode 100644 index 000000000..4c16c8c31 --- /dev/null +++ b/fs/xfs/libxfs/xfs_btree.c @@ -0,0 +1,5099 @@ +// 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 (cur->bc_ops->diff_two_keys(cur, &hkey, &max_hkey) + > 0) + 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 (cur->bc_ops->diff_two_keys(cur, hkey, max_hkey) > 0) + 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 && + !(cur->bc_ops->diff_two_keys(cur, nlkey, lkey) != 0 || + cur->bc_ops->diff_two_keys(cur, nhkey, hkey) != 0)) + 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. 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. + */ +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) + 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) +{ + unsigned long long node_blocks = limits[1]; + 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; + int64_t diff; + 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 high_key(rec) < low_key. */ + if (firstrec) { + cur->bc_ops->init_high_key_from_rec(&rec_key, recp); + firstrec = false; + diff = cur->bc_ops->diff_two_keys(cur, low_key, + &rec_key); + if (diff > 0) + goto advloop; + } + + /* Stop if high_key < low_key(rec). */ + cur->bc_ops->init_key_from_rec(&rec_key, recp); + diff = cur->bc_ops->diff_two_keys(cur, &rec_key, high_key); + if (diff > 0) + 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; + int64_t ldiff; + int64_t hdiff; + 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); + ldiff = cur->bc_ops->diff_two_keys(cur, &rec_hkey, + low_key); + + cur->bc_ops->init_key_from_rec(&rec_key, recp); + hdiff = cur->bc_ops->diff_two_keys(cur, high_key, + &rec_key); + + /* + * 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 (ldiff >= 0 && hdiff >= 0) { + error = fn(cur, recp, priv); + if (error) + break; + } else if (hdiff < 0) { + /* Record is larger than high key; pop. */ + goto pop_up; + } + 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); + + ldiff = cur->bc_ops->diff_two_keys(cur, hkp, low_key); + hdiff = cur->bc_ops->diff_two_keys(cur, high_key, lkp); + + /* + * 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 (ldiff >= 0 && hdiff >= 0) { + 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; + } else if (hdiff < 0) { + /* The low key is larger than the upper range; pop. */ + goto pop_up; + } + 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; +} + +/* + * 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_rec rec; + union xfs_btree_key low_key; + union xfs_btree_key high_key; + + /* Find the keys of both ends of the interval. */ + cur->bc_rec = *high_rec; + cur->bc_ops->init_rec_from_cur(cur, &rec); + cur->bc_ops->init_key_from_rec(&high_key, &rec); + + cur->bc_rec = *low_rec; + cur->bc_ops->init_rec_from_cur(cur, &rec); + cur->bc_ops->init_key_from_rec(&low_key, &rec); + + /* Enforce low key < high key. */ + if (cur->bc_ops->diff_two_keys(cur, &low_key, &high_key) > 0) + 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); +} + +/* If there's an extent, we're done. */ +STATIC int +xfs_btree_has_record_helper( + struct xfs_btree_cur *cur, + const union xfs_btree_rec *rec, + void *priv) +{ + return -ECANCELED; +} + +/* Is there a record covering a given range of keys? */ +int +xfs_btree_has_record( + struct xfs_btree_cur *cur, + const union xfs_btree_irec *low, + const union xfs_btree_irec *high, + bool *exists) +{ + int error; + + error = xfs_btree_query_range(cur, low, high, + &xfs_btree_has_record_helper, NULL); + if (error == -ECANCELED) { + *exists = true; + return 0; + } + *exists = false; + return error; +} + +/* 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(); +} |