diff options
Diffstat (limited to 'fs/xfs/libxfs/xfs_btree.c')
| -rw-r--r-- | fs/xfs/libxfs/xfs_btree.c | 4069 |
1 files changed, 4069 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c new file mode 100644 index 000000000000..ba35c9ccb8f9 --- /dev/null +++ b/fs/xfs/libxfs/xfs_btree.c @@ -0,0 +1,4069 @@ +/* + * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc. + * All Rights Reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it would be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ +#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_sb.h" +#include "xfs_ag.h" +#include "xfs_mount.h" +#include "xfs_inode.h" +#include "xfs_trans.h" +#include "xfs_inode_item.h" +#include "xfs_buf_item.h" +#include "xfs_btree.h" +#include "xfs_error.h" +#include "xfs_trace.h" +#include "xfs_cksum.h" +#include "xfs_alloc.h" + +/* + * Cursor allocation zone. + */ +kmem_zone_t *xfs_btree_cur_zone; + +/* + * Btree magic numbers. + */ +static const __uint32_t xfs_magics[2][XFS_BTNUM_MAX] = { + { XFS_ABTB_MAGIC, XFS_ABTC_MAGIC, XFS_BMAP_MAGIC, XFS_IBT_MAGIC, + XFS_FIBT_MAGIC }, + { XFS_ABTB_CRC_MAGIC, XFS_ABTC_CRC_MAGIC, + XFS_BMAP_CRC_MAGIC, XFS_IBT_CRC_MAGIC, XFS_FIBT_CRC_MAGIC } +}; +#define xfs_btree_magic(cur) \ + xfs_magics[!!((cur)->bc_flags & XFS_BTREE_CRC_BLOCKS)][cur->bc_btnum] + + +STATIC int /* error (0 or EFSCORRUPTED) */ +xfs_btree_check_lblock( + struct xfs_btree_cur *cur, /* btree cursor */ + struct xfs_btree_block *block, /* btree long form block pointer */ + int level, /* level of the btree block */ + struct xfs_buf *bp) /* buffer for block, if any */ +{ + int lblock_ok = 1; /* block passes checks */ + struct xfs_mount *mp; /* file system mount point */ + + mp = cur->bc_mp; + + if (xfs_sb_version_hascrc(&mp->m_sb)) { + lblock_ok = lblock_ok && + uuid_equal(&block->bb_u.l.bb_uuid, &mp->m_sb.sb_uuid) && + block->bb_u.l.bb_blkno == cpu_to_be64( + bp ? bp->b_bn : XFS_BUF_DADDR_NULL); + } + + lblock_ok = lblock_ok && + be32_to_cpu(block->bb_magic) == xfs_btree_magic(cur) && + be16_to_cpu(block->bb_level) == level && + be16_to_cpu(block->bb_numrecs) <= + cur->bc_ops->get_maxrecs(cur, level) && + block->bb_u.l.bb_leftsib && + (block->bb_u.l.bb_leftsib == cpu_to_be64(NULLDFSBNO) || + XFS_FSB_SANITY_CHECK(mp, + be64_to_cpu(block->bb_u.l.bb_leftsib))) && + block->bb_u.l.bb_rightsib && + (block->bb_u.l.bb_rightsib == cpu_to_be64(NULLDFSBNO) || + XFS_FSB_SANITY_CHECK(mp, + be64_to_cpu(block->bb_u.l.bb_rightsib))); + + if (unlikely(XFS_TEST_ERROR(!lblock_ok, mp, + XFS_ERRTAG_BTREE_CHECK_LBLOCK, + XFS_RANDOM_BTREE_CHECK_LBLOCK))) { + if (bp) + trace_xfs_btree_corrupt(bp, _RET_IP_); + XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, mp); + return -EFSCORRUPTED; + } + return 0; +} + +STATIC int /* error (0 or EFSCORRUPTED) */ +xfs_btree_check_sblock( + struct xfs_btree_cur *cur, /* btree cursor */ + struct xfs_btree_block *block, /* btree short form block pointer */ + int level, /* level of the btree block */ + struct xfs_buf *bp) /* buffer containing block */ +{ + struct xfs_mount *mp; /* file system mount point */ + struct xfs_buf *agbp; /* buffer for ag. freespace struct */ + struct xfs_agf *agf; /* ag. freespace structure */ + xfs_agblock_t agflen; /* native ag. freespace length */ + int sblock_ok = 1; /* block passes checks */ + + mp = cur->bc_mp; + agbp = cur->bc_private.a.agbp; + agf = XFS_BUF_TO_AGF(agbp); + agflen = be32_to_cpu(agf->agf_length); + + if (xfs_sb_version_hascrc(&mp->m_sb)) { + sblock_ok = sblock_ok && + uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_uuid) && + block->bb_u.s.bb_blkno == cpu_to_be64( + bp ? bp->b_bn : XFS_BUF_DADDR_NULL); + } + + sblock_ok = sblock_ok && + be32_to_cpu(block->bb_magic) == xfs_btree_magic(cur) && + be16_to_cpu(block->bb_level) == level && + be16_to_cpu(block->bb_numrecs) <= + cur->bc_ops->get_maxrecs(cur, level) && + (block->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK) || + be32_to_cpu(block->bb_u.s.bb_leftsib) < agflen) && + block->bb_u.s.bb_leftsib && + (block->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK) || + be32_to_cpu(block->bb_u.s.bb_rightsib) < agflen) && + block->bb_u.s.bb_rightsib; + + if (unlikely(XFS_TEST_ERROR(!sblock_ok, mp, + XFS_ERRTAG_BTREE_CHECK_SBLOCK, + XFS_RANDOM_BTREE_CHECK_SBLOCK))) { + if (bp) + trace_xfs_btree_corrupt(bp, _RET_IP_); + XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, mp); + 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 (long) pointer is ok. + */ +int /* error (0 or EFSCORRUPTED) */ +xfs_btree_check_lptr( + struct xfs_btree_cur *cur, /* btree cursor */ + xfs_dfsbno_t bno, /* btree block disk address */ + int level) /* btree block level */ +{ + XFS_WANT_CORRUPTED_RETURN( + level > 0 && + bno != NULLDFSBNO && + XFS_FSB_SANITY_CHECK(cur->bc_mp, bno)); + return 0; +} + +#ifdef DEBUG +/* + * Check that (short) pointer is ok. + */ +STATIC int /* error (0 or EFSCORRUPTED) */ +xfs_btree_check_sptr( + struct xfs_btree_cur *cur, /* btree cursor */ + xfs_agblock_t bno, /* btree block disk address */ + int level) /* btree block level */ +{ + xfs_agblock_t agblocks = cur->bc_mp->m_sb.sb_agblocks; + + XFS_WANT_CORRUPTED_RETURN( + level > 0 && + bno != NULLAGBLOCK && + bno != 0 && + bno < agblocks); + return 0; +} + +/* + * Check that block ptr is ok. + */ +STATIC int /* error (0 or EFSCORRUPTED) */ +xfs_btree_check_ptr( + struct xfs_btree_cur *cur, /* btree cursor */ + union xfs_btree_ptr *ptr, /* btree block disk address */ + int index, /* offset from ptr to check */ + int level) /* btree block level */ +{ + if (cur->bc_flags & XFS_BTREE_LONG_PTRS) { + return xfs_btree_check_lptr(cur, + be64_to_cpu((&ptr->l)[index]), level); + } else { + return xfs_btree_check_sptr(cur, + be32_to_cpu((&ptr->s)[index]), level); + } +} +#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 modifcation 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_fspriv; + + if (!xfs_sb_version_hascrc(&bp->b_target->bt_mount->m_sb)) + 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) +{ + if (xfs_sb_version_hascrc(&bp->b_target->bt_mount->m_sb)) + 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 modifcation 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_fspriv; + + if (!xfs_sb_version_hascrc(&bp->b_target->bt_mount->m_sb)) + 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) +{ + if (xfs_sb_version_hascrc(&bp->b_target->bt_mount->m_sb)) + return xfs_buf_verify_cksum(bp, XFS_BTREE_SBLOCK_CRC_OFF); + + return true; +} + +/* + * Delete the btree cursor. + */ +void +xfs_btree_del_cursor( + xfs_btree_cur_t *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 in the face of an error, we + * need to make sure to 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_bufs[i]) + xfs_trans_brelse(cur->bc_tp, cur->bc_bufs[i]); + else if (!error) + break; + } + /* + * Can't free a bmap cursor without having dealt with the + * allocated indirect blocks' accounting. + */ + ASSERT(cur->bc_btnum != XFS_BTNUM_BMAP || + cur->bc_private.b.allocated == 0); + /* + * Free the cursor. + */ + kmem_zone_free(xfs_btree_cur_zone, cur); +} + +/* + * Duplicate the btree cursor. + * Allocate a new one, copy the record, re-get the buffers. + */ +int /* error */ +xfs_btree_dup_cursor( + xfs_btree_cur_t *cur, /* input cursor */ + xfs_btree_cur_t **ncur) /* output cursor */ +{ + xfs_buf_t *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 */ + xfs_btree_cur_t *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_ptrs[i] = cur->bc_ptrs[i]; + new->bc_ra[i] = cur->bc_ra[i]; + bp = cur->bc_bufs[i]; + if (bp) { + error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, + XFS_BUF_ADDR(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_bufs[i] = 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! + */ + +/* + * 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 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. + */ +STATIC 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. + */ +STATIC 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 block pointer in the btree block. + */ +STATIC 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)); +} + +/* + * 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; + + ifp = XFS_IFORK_PTR(cur->bc_private.b.ip, cur->bc_private.b.whichfork); + 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. + */ +STATIC 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_bufs[level]; + return XFS_BUF_TO_BLOCK(*bpp); +} + +/* + * Get a buffer for the block, return it with no data read. + * Long-form addressing. + */ +xfs_buf_t * /* buffer for fsbno */ +xfs_btree_get_bufl( + xfs_mount_t *mp, /* file system mount point */ + xfs_trans_t *tp, /* transaction pointer */ + xfs_fsblock_t fsbno, /* file system block number */ + uint lock) /* lock flags for get_buf */ +{ + xfs_daddr_t d; /* real disk block address */ + + ASSERT(fsbno != NULLFSBLOCK); + d = XFS_FSB_TO_DADDR(mp, fsbno); + return xfs_trans_get_buf(tp, mp->m_ddev_targp, d, mp->m_bsize, lock); +} + +/* + * Get a buffer for the block, return it with no data read. + * Short-form addressing. + */ +xfs_buf_t * /* buffer for agno/agbno */ +xfs_btree_get_bufs( + xfs_mount_t *mp, /* file system mount point */ + xfs_trans_t *tp, /* transaction pointer */ + xfs_agnumber_t agno, /* allocation group number */ + xfs_agblock_t agbno, /* allocation group block number */ + uint lock) /* lock flags for get_buf */ +{ + xfs_daddr_t d; /* real disk block address */ + + ASSERT(agno != NULLAGNUMBER); + ASSERT(agbno != NULLAGBLOCK); + d = XFS_AGB_TO_DADDR(mp, agno, agbno); + return xfs_trans_get_buf(tp, mp->m_ddev_targp, d, mp->m_bsize, lock); +} + +/* + * Check for the cursor referring to the last block at the given level. + */ +int /* 1=is last block, 0=not last block */ +xfs_btree_islastblock( + xfs_btree_cur_t *cur, /* btree cursor */ + int level) /* level to check */ +{ + struct xfs_btree_block *block; /* generic btree block pointer */ + xfs_buf_t *bp; /* buffer containing block */ + + block = xfs_btree_get_block(cur, level, &bp); + xfs_btree_check_block(cur, block, level, bp); + if (cur->bc_flags & XFS_BTREE_LONG_PTRS) + return block->bb_u.l.bb_rightsib == cpu_to_be64(NULLDFSBNO); + else + return block->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK); +} + +/* + * 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( + xfs_btree_cur_t *cur, /* btree cursor */ + int level) /* level to change */ +{ + struct xfs_btree_block *block; /* generic btree block pointer */ + xfs_buf_t *bp; /* buffer containing block */ + + /* + * Get the block pointer for this level. + */ + block = xfs_btree_get_block(cur, level, &bp); + xfs_btree_check_block(cur, block, level, bp); + /* + * 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_ptrs[level] = 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( + xfs_btree_cur_t *cur, /* btree cursor */ + int level) /* level to change */ +{ + struct xfs_btree_block *block; /* generic btree block pointer */ + xfs_buf_t *bp; /* buffer containing block */ + + /* + * Get the block pointer for this level. + */ + block = xfs_btree_get_block(cur, level, &bp); + xfs_btree_check_block(cur, block, level, bp); + /* + * 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_ptrs[level] = 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( + __int64_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 */ + __int64_t imask; /* mask for current bit number */ + + ASSERT(fields != 0); + /* + * Find the lowest bit, so the first byte offset. + */ + for (i = 0, imask = 1LL; ; i++, imask <<= 1) { + if (imask & fields) { + *first = offsets[i]; + break; + } + } + /* + * Find the highest bit, so the last byte offset. + */ + for (i = nbits - 1, imask = 1LL << 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 */ + uint lock, /* lock flags for read_buf */ + 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; + + ASSERT(fsbno != NULLFSBLOCK); + d = XFS_FSB_TO_DADDR(mp, fsbno); + error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, d, + mp->m_bsize, lock, &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_dfsbno_t left = be64_to_cpu(block->bb_u.l.bb_leftsib); + xfs_dfsbno_t right = be64_to_cpu(block->bb_u.l.bb_rightsib); + + if ((lr & XFS_BTCUR_LEFTRA) && left != NULLDFSBNO) { + xfs_btree_reada_bufl(cur->bc_mp, left, 1, + cur->bc_ops->buf_ops); + rval++; + } + + if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLDFSBNO) { + 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_private.a.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_private.a.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_ra[lev] | lr) == cur->bc_ra[lev]) + return 0; + + cur->bc_ra[lev] |= lr; + block = XFS_BUF_TO_BLOCK(cur->bc_bufs[lev]); + + 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 xfs_daddr_t +xfs_btree_ptr_to_daddr( + struct xfs_btree_cur *cur, + union xfs_btree_ptr *ptr) +{ + if (cur->bc_flags & XFS_BTREE_LONG_PTRS) { + ASSERT(ptr->l != cpu_to_be64(NULLDFSBNO)); + + return XFS_FSB_TO_DADDR(cur->bc_mp, be64_to_cpu(ptr->l)); + } else { + ASSERT(cur->bc_private.a.agno != NULLAGNUMBER); + ASSERT(ptr->s != cpu_to_be32(NULLAGBLOCK)); + + return XFS_AGB_TO_DADDR(cur->bc_mp, cur->bc_private.a.agno, + be32_to_cpu(ptr->s)); + } +} + +/* + * 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_buf_readahead(cur->bc_mp->m_ddev_targp, + xfs_btree_ptr_to_daddr(cur, ptr), + 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( + xfs_btree_cur_t *cur, /* btree cursor */ + int lev, /* level in btree */ + xfs_buf_t *bp) /* new buffer to set */ +{ + struct xfs_btree_block *b; /* btree block */ + + if (cur->bc_bufs[lev]) + xfs_trans_brelse(cur->bc_tp, cur->bc_bufs[lev]); + cur->bc_bufs[lev] = bp; + cur->bc_ra[lev] = 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(NULLDFSBNO)) + cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA; + if (b->bb_u.l.bb_rightsib == cpu_to_be64(NULLDFSBNO)) + cur->bc_ra[lev] |= XFS_BTCUR_RIGHTRA; + } else { + if (b->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK)) + cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA; + if (b->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK)) + cur->bc_ra[lev] |= XFS_BTCUR_RIGHTRA; + } +} + +STATIC int +xfs_btree_ptr_is_null( + struct xfs_btree_cur *cur, + union xfs_btree_ptr *ptr) +{ + if (cur->bc_flags & XFS_BTREE_LONG_PTRS) + return ptr->l == cpu_to_be64(NULLDFSBNO); + else + return ptr->s == cpu_to_be32(NULLAGBLOCK); +} + +STATIC 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(NULLDFSBNO); + else + ptr->s = cpu_to_be32(NULLAGBLOCK); +} + +/* + * Get/set/init sibling pointers + */ +STATIC 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; + } +} + +STATIC void +xfs_btree_set_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) + 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, + __u32 magic, + __u16 level, + __u16 numrecs, + __u64 owner, + unsigned int flags) +{ + 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(NULLDFSBNO); + buf->bb_u.l.bb_rightsib = cpu_to_be64(NULLDFSBNO); + if (flags & XFS_BTREE_CRC_BLOCKS) { + 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_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 (flags & XFS_BTREE_CRC_BLOCKS) { + 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_uuid); + buf->bb_u.s.bb_lsn = 0; + } + } +} + +void +xfs_btree_init_block( + struct xfs_mount *mp, + struct xfs_buf *bp, + __u32 magic, + __u16 level, + __u16 numrecs, + __u64 owner, + unsigned int flags) +{ + xfs_btree_init_block_int(mp, XFS_BUF_TO_BLOCK(bp), bp->b_bn, + magic, level, numrecs, owner, flags); +} + +STATIC 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_private.b.ip->i_ino; + else + owner = cur->bc_private.a.agno; + + xfs_btree_init_block_int(cur->bc_mp, XFS_BUF_TO_BLOCK(bp), bp->b_bn, + xfs_btree_magic(cur), 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_ADDR(bp))); + else { + ptr->s = cpu_to_be32(xfs_daddr_to_agbno(cur->bc_mp, + XFS_BUF_ADDR(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; + default: + ASSERT(0); + } +} + +STATIC int +xfs_btree_get_buf_block( + struct xfs_btree_cur *cur, + 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; + + /* need to sort out how callers deal with failures first */ + ASSERT(!(flags & XBF_TRYLOCK)); + + d = xfs_btree_ptr_to_daddr(cur, ptr); + *bpp = xfs_trans_get_buf(cur->bc_tp, mp->m_ddev_targp, d, + mp->m_bsize, flags); + + if (!*bpp) + return -ENOMEM; + + (*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, + 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)); + + d = xfs_btree_ptr_to_daddr(cur, ptr); + 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. + */ +STATIC void +xfs_btree_copy_keys( + struct xfs_btree_cur *cur, + union xfs_btree_key *dst_key, + 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. + */ +STATIC void +xfs_btree_copy_ptrs( + struct xfs_btree_cur *cur, + union xfs_btree_ptr *dst_ptr, + 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) +{ + XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY); + XFS_BTREE_TRACE_ARGBII(cur, bp, first, 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_private.b.ip, + xfs_ilog_fbroot(cur->bc_private.b.whichfork)); + } + + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); +} + +/* + * 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_BTREE_TRACE_CURSOR(cur, XBT_ENTRY); + XFS_BTREE_TRACE_ARGBII(cur, bp, first, 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); + + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); +} + +/* + * 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 */ +{ + XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY); + XFS_BTREE_TRACE_ARGBII(cur, bp, first, last); + + 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_private.b.ip, + xfs_ilog_fbroot(cur->bc_private.b.whichfork)); + } + + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); +} + +/* + * 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 */ + int 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 + }; + + XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY); + XFS_BTREE_TRACE_ARGBI(cur, bp, fields); + + 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_private.b.ip, + xfs_ilog_fbroot(cur->bc_private.b.whichfork)); + } + + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); +} + +/* + * 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; + + XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY); + XFS_BTREE_TRACE_ARGI(cur, level); + + 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_ptrs[level] <= 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_ptrs[lev] <= 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_ptrs[lev], 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_ptrs[lev] = 1; + } +out1: + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); + *stat = 1; + return 0; + +out0: + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); + *stat = 0; + return 0; + +error0: + XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR); + 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; + xfs_buf_t *bp; + int error; /* error return value */ + int lev; + union xfs_btree_ptr ptr; + + XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY); + XFS_BTREE_TRACE_ARGI(cur, level); + + 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_ptrs[level] > 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_ptrs[lev] > 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_ptrs[lev], 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_ptrs[lev] = xfs_btree_get_numrecs(block); + } +out1: + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); + *stat = 1; + return 0; + +out0: + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); + *stat = 0; + return 0; + +error0: + XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR); + return error; +} + +STATIC int +xfs_btree_lookup_get_block( + struct xfs_btree_cur *cur, /* btree cursor */ + int level, /* level in the btree */ + 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 */ + 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_bufs[level]; + if (bp && XFS_BUF_ADDR(bp) == xfs_btree_ptr_to_daddr(cur, pp)) { + *blkp = XFS_BUF_TO_BLOCK(bp); + return 0; + } + + error = xfs_btree_read_buf_block(cur, pp, 0, blkp, &bp); + if (error) + return error; + + xfs_btree_setbuf(cur, level, bp); + return 0; +} + +/* + * 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_TRACE_CURSOR(cur, XBT_ENTRY); + XFS_BTREE_TRACE_ARGI(cur, dir); + + XFS_BTREE_STATS_INC(cur, lookup); + + 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. */ + ASSERT(level == 0 && cur->bc_nlevels == 1); + + cur->bc_ptrs[0] = dir != XFS_LOOKUP_LE; + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); + *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); + +#ifdef DEBUG + error = xfs_btree_check_ptr(cur, pp, 0, level); + if (error) + goto error0; +#endif + cur->bc_ptrs[level] = 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_ptrs[0] = keyno; + error = xfs_btree_increment(cur, 0, &i); + if (error) + goto error0; + XFS_WANT_CORRUPTED_RETURN(i == 1); + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); + *stat = 1; + return 0; + } + } else if (dir == XFS_LOOKUP_LE && diff > 0) + keyno--; + cur->bc_ptrs[0] = 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; + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); + return 0; + +error0: + XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR); + return error; +} + +/* + * Update keys at all levels from here to the root along the cursor's path. + */ +STATIC int +xfs_btree_updkey( + struct xfs_btree_cur *cur, + union xfs_btree_key *keyp, + int level) +{ + struct xfs_btree_block *block; + struct xfs_buf *bp; + union xfs_btree_key *kp; + int ptr; + + XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY); + XFS_BTREE_TRACE_ARGIK(cur, level, keyp); + + ASSERT(!(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) || level >= 1); + + /* + * 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. + */ + for (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) { + XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR); + return error; + } +#endif + ptr = cur->bc_ptrs[level]; + kp = xfs_btree_key_addr(cur, ptr, block); + xfs_btree_copy_keys(cur, kp, keyp, 1); + xfs_btree_log_keys(cur, bp, ptr, ptr); + } + + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); + 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; + + XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY); + XFS_BTREE_TRACE_ARGR(cur, rec); + + /* 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_ptrs[0]; + 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); + } + + /* Updating first rec in leaf. Pass new key value up to our parent. */ + if (ptr == 1) { + union xfs_btree_key key; + + cur->bc_ops->init_key_from_rec(&key, rec); + error = xfs_btree_updkey(cur, &key, 1); + if (error) + goto error0; + } + + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); + return 0; + +error0: + XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR); + 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 */ +{ + union xfs_btree_key key; /* btree key */ + 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 */ + 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 */ + + XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY); + XFS_BTREE_TRACE_ARGI(cur, level); + + 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_ptrs[level] <= 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); +#ifdef DEBUG + error = xfs_btree_check_ptr(cur, rpp, 0, level); + if (error) + goto error0; +#endif + 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 */ +#ifdef DEBUG + int i; /* loop index */ + + for (i = 0; i < rrecs; i++) { + error = xfs_btree_check_ptr(cur, rpp, i + 1, level); + if (error) + goto error0; + } +#endif + 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); + + /* + * If it's the first record in the block, we'll need a key + * structure to pass up to the next level (updkey). + */ + cur->bc_ops->init_key_from_rec(&key, + xfs_btree_rec_addr(cur, 1, right)); + rkp = &key; + } + + /* Update the parent key values of right. */ + error = xfs_btree_updkey(cur, rkp, level + 1); + if (error) + goto error0; + + /* Slide the cursor value left one. */ + cur->bc_ptrs[level]--; + + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); + *stat = 1; + return 0; + +out0: + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); + *stat = 0; + return 0; + +error0: + XFS_BTREE_TRACE_CURSOR(cur, XBT_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 */ +{ + union xfs_btree_key key; /* btree key */ + 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 */ + + XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY); + XFS_BTREE_TRACE_ARGI(cur, level); + + 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_ptrs[level] >= 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); + +#ifdef DEBUG + for (i = rrecs - 1; i >= 0; i--) { + error = xfs_btree_check_ptr(cur, rpp, i, level); + if (error) + goto error0; + } +#endif + + xfs_btree_shift_keys(cur, rkp, 1, rrecs); + xfs_btree_shift_ptrs(cur, rpp, 1, rrecs); + +#ifdef DEBUG + error = xfs_btree_check_ptr(cur, lpp, 0, level); + if (error) + goto error0; +#endif + + /* 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); + + cur->bc_ops->init_key_from_rec(&key, rrp); + rkp = &key; + + ASSERT(cur->bc_ops->recs_inorder(cur, rrp, + xfs_btree_rec_addr(cur, 2, right))); + } + + /* + * 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); + XFS_WANT_CORRUPTED_GOTO(i == 1, error0); + + error = xfs_btree_increment(tcur, level, &i); + if (error) + goto error1; + + error = xfs_btree_updkey(tcur, rkp, level + 1); + if (error) + goto error1; + + xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR); + + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); + *stat = 1; + return 0; + +out0: + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); + *stat = 0; + return 0; + +error0: + XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR); + return error; + +error1: + XFS_BTREE_TRACE_CURSOR(tcur, XBT_ERROR); + 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 */ +#ifdef DEBUG + int i; +#endif + + XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY); + XFS_BTREE_TRACE_ARGIPK(cur, level, *ptrp, key); + + 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, 0, &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_ptrs[level] <= rrecs + 1) + rrecs++; + src_index = (lrecs - rrecs + 1); + + XFS_BTREE_STATS_ADD(cur, moves, 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); + +#ifdef DEBUG + for (i = src_index; i < rrecs; i++) { + error = xfs_btree_check_ptr(cur, lpp, i, level); + if (error) + goto error0; + } +#endif + + 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); + + /* Grab the keys to the entries moved to the right block */ + xfs_btree_copy_keys(cur, key, rkp, 1); + } 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); + + xfs_btree_copy_recs(cur, rrp, lrp, rrecs); + xfs_btree_log_recs(cur, rbp, 1, rrecs); + + cur->bc_ops->init_key_from_rec(key, + xfs_btree_rec_addr(cur, 1, right)); + } + + + /* + * Find the left block number by looking in the buffer. + * Adjust numrecs, 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); + + lrecs -= rrecs; + xfs_btree_set_numrecs(left, lrecs); + xfs_btree_set_numrecs(right, xfs_btree_get_numrecs(right) + rrecs); + + 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); + } + /* + * 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_ptrs[level] > lrecs + 1) { + xfs_btree_setbuf(cur, level, rbp); + cur->bc_ptrs[level] -= 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_ptrs[level + 1]++; + } + *ptrp = rptr; + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); + *stat = 1; + return 0; +out0: + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); + *stat = 0; + return 0; + +error0: + XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR); + return error; +} + +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 = PF_FSTRANS; + + /* + * 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_SWAPWRITE | PF_KSWAPD; + + current_set_flags_nested(&pflags, new_pflags); + + args->result = __xfs_btree_split(args->cur, args->level, args->ptrp, + args->key, args->curp, args->stat); + complete(args->done); + + current_restore_flags_nested(&pflags, new_pflags); +} + +/* + * 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; +} + + +/* + * 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 */ +#ifdef DEBUG + int i; /* loop counter */ +#endif + + XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY); + 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) { + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); + return 0; + } + XFS_BTREE_STATS_INC(cur, alloc); + + /* Copy the root into a real block. */ + error = xfs_btree_get_buf_block(cur, &nptr, 0, &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) { + if (cur->bc_flags & XFS_BTREE_LONG_PTRS) + cblock->bb_u.l.bb_blkno = cpu_to_be64(cbp->b_bn); + else + cblock->bb_u.s.bb_blkno = cpu_to_be64(cbp->b_bn); + } + + be16_add_cpu(&block->bb_level, 1); + xfs_btree_set_numrecs(block, 1); + cur->bc_nlevels++; + cur->bc_ptrs[level + 1] = 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); +#ifdef DEBUG + for (i = 0; i < be16_to_cpu(cblock->bb_numrecs); i++) { + error = xfs_btree_check_ptr(cur, pp, i, level); + if (error) + goto error0; + } +#endif + xfs_btree_copy_ptrs(cur, cpp, pp, xfs_btree_get_numrecs(cblock)); + +#ifdef DEBUG + error = xfs_btree_check_ptr(cur, &nptr, 0, level); + if (error) + goto error0; +#endif + xfs_btree_copy_ptrs(cur, pp, &nptr, 1); + + xfs_iroot_realloc(cur->bc_private.b.ip, + 1 - xfs_btree_get_numrecs(cblock), + cur->bc_private.b.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_private.b.whichfork); + *stat = 1; + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); + return 0; +error0: + XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR); + 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_TRACE_CURSOR(cur, XBT_ENTRY); + 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, 0, &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) { + xfs_btree_copy_keys(cur, + xfs_btree_key_addr(cur, 1, new), + xfs_btree_key_addr(cur, 1, left), 1); + xfs_btree_copy_keys(cur, + xfs_btree_key_addr(cur, 2, new), + xfs_btree_key_addr(cur, 1, right), 1); + } else { + cur->bc_ops->init_key_from_rec( + xfs_btree_key_addr(cur, 1, new), + xfs_btree_rec_addr(cur, 1, left)); + cur->bc_ops->init_key_from_rec( + xfs_btree_key_addr(cur, 2, new), + xfs_btree_rec_addr(cur, 1, right)); + } + 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_ptrs[cur->bc_nlevels] = nptr; + cur->bc_nlevels++; + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); + *stat = 1; + return 0; +error0: + XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR); + return error; +out0: + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); + *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_rec *nrec, /* new record */ + int *stat) +{ + union xfs_btree_key key; /* new btree key value */ + int error = 0; + + if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) && + level == cur->bc_nlevels - 1) { + struct xfs_inode *ip = cur->bc_private.b.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_private.b.whichfork); + } 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_ptrs[level]; + 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_ptrs[level]; + cur->bc_ops->init_rec_from_key(&key, nrec); + 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 *recp, /* i/o: record data inserted */ + 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_key key; /* btree key */ + union xfs_btree_ptr nptr; /* new block ptr */ + struct xfs_btree_cur *ncur; /* new btree cursor */ + union xfs_btree_rec nrec; /* new record count */ + int optr; /* old key/record index */ + int ptr; /* key/record index */ + int numrecs;/* number of records */ + int error; /* error return value */ +#ifdef DEBUG + int i; +#endif + + XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY); + XFS_BTREE_TRACE_ARGIPR(cur, level, *ptrp, recp); + + ncur = NULL; + + /* + * 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); + + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); + return error; + } + + /* If we're off the left edge, return failure. */ + ptr = cur->bc_ptrs[level]; + if (ptr == 0) { + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); + *stat = 0; + return 0; + } + + /* Make a key out of the record data to be inserted, and save it. */ + cur->bc_ops->init_key_from_rec(&key, recp); + + optr = ptr; + + XFS_BTREE_STATS_INC(cur, insrec); + + /* Get pointers to the btree buffer and block. */ + 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; + + /* 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, recp, + 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, &nrec, 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) + return error; +#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); + +#ifdef DEBUG + for (i = numrecs - ptr; i >= 0; i--) { + error = xfs_btree_check_ptr(cur, pp, i, level); + if (error) + return error; + } +#endif + + xfs_btree_shift_keys(cur, kp, 1, numrecs - ptr + 1); + xfs_btree_shift_ptrs(cur, pp, 1, numrecs - ptr + 1); + +#ifdef DEBUG + error = xfs_btree_check_ptr(cur, ptrp, 0, level); + if (error) + goto error0; +#endif + + /* 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, recp, 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 inserted at the start of a block, update the parents' keys. */ + if (optr == 1) { + error = xfs_btree_updkey(cur, &key, level + 1); + 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, recp, + 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)) { + *recp = nrec; + *curp = ncur; + } + + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); + *stat = 1; + return 0; + +error0: + XFS_BTREE_TRACE_CURSOR(cur, XBT_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_rec rec; /* record to insert */ + + level = 0; + ncur = NULL; + pcur = cur; + + xfs_btree_set_ptr_null(cur, &nptr); + cur->bc_ops->init_rec_from_cur(cur, &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, &ncur, &i); + if (error) { + if (pcur != cur) + xfs_btree_del_cursor(pcur, XFS_BTREE_ERROR); + goto error0; + } + + XFS_WANT_CORRUPTED_GOTO(i == 1, 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)); + + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); + *stat = i; + return 0; +error0: + XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR); + 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_private.b.whichfork; + struct xfs_inode *ip = cur->bc_private.b.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; +#ifdef DEBUG + union xfs_btree_ptr ptr; + int i; +#endif + + XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY); + + 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_private.b.ip, index, + cur->bc_private.b.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); +#ifdef DEBUG + for (i = 0; i < numrecs; i++) { + int error; + + error = xfs_btree_check_ptr(cur, cpp, i, level - 1); + if (error) { + XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR); + return error; + } + } +#endif + xfs_btree_copy_ptrs(cur, pp, cpp, numrecs); + + cur->bc_ops->free_block(cur, cbp); + XFS_BTREE_STATS_INC(cur, free); + + cur->bc_bufs[level - 1] = NULL; + be16_add_cpu(&block->bb_level, -1); + xfs_trans_log_inode(cur->bc_tp, ip, + XFS_ILOG_CORE | xfs_ilog_fbroot(cur->bc_private.b.whichfork)); + cur->bc_nlevels--; +out0: + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); + 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_TRACE_CURSOR(cur, XBT_ENTRY); + 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 = cur->bc_ops->free_block(cur, bp); + if (error) { + XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR); + return error; + } + + XFS_BTREE_STATS_INC(cur, free); + + cur->bc_bufs[level] = NULL; + cur->bc_ra[level] = 0; + cur->bc_nlevels--; + + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); + 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; + } + + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); + *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_key key; /* storage for keyp */ + union xfs_btree_key *keyp = &key; /* passed to the next level */ + 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 */ + + XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY); + XFS_BTREE_TRACE_ARGI(cur, level); + + tcur = NULL; + + /* Get the index of the entry being deleted, check for nothing there. */ + ptr = cur->bc_ptrs[level]; + if (ptr == 0) { + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); + *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) { + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); + *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); + +#ifdef DEBUG + for (i = 0; i < numrecs - ptr; i++) { + error = xfs_btree_check_ptr(cur, lpp, i, level); + if (error) + goto error0; + } +#endif + + 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); + } + + /* + * If it's the first record in the block, we'll need to pass a + * key up to the next level (updkey). + */ + if (ptr == 1) + keyp = xfs_btree_key_addr(cur, 1, block); + } 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); + } + + /* + * If it's the first record in the block, we'll need a key + * structure to pass up to the next level (updkey). + */ + if (ptr == 1) { + cur->bc_ops->init_key_from_rec(&key, + xfs_btree_rec_addr(cur, 1, block)); + keyp = &key; + } + } + + /* + * 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_private.b.ip, -1, + cur->bc_private.b.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 (ptr == 1) { + error = xfs_btree_updkey(cur, keyp, level + 1); + 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); + XFS_WANT_CORRUPTED_GOTO(i == 1, error0); + + error = xfs_btree_increment(tcur, level, &i); + if (error) + goto error0; + XFS_WANT_CORRUPTED_GOTO(i == 1, error0); + + i = xfs_btree_lastrec(tcur, level); + XFS_WANT_CORRUPTED_GOTO(i == 1, 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); + XFS_WANT_CORRUPTED_GOTO(i == 1, error0); + + error = xfs_btree_decrement(tcur, level, &i); + if (error) + goto error0; + XFS_WANT_CORRUPTED_GOTO(i == 1, 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); + XFS_WANT_CORRUPTED_GOTO(i == 1, error0); + + error = xfs_btree_decrement(tcur, level, &i); + if (error) + goto error0; + i = xfs_btree_firstrec(tcur, level); + XFS_WANT_CORRUPTED_GOTO(i == 1, 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_ptrs[0]++; + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); + *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); +#ifdef DEBUG + for (i = 1; i < rrecs; i++) { + error = xfs_btree_check_ptr(cur, rpp, i, level); + if (error) + goto error0; + } +#endif + 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 = cur->bc_ops->free_block(cur, rbp); + if (error) + goto error0; + XFS_BTREE_STATS_INC(cur, free); + + /* + * 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_bufs[level] = lbp; + cur->bc_ptrs[level] += lrecs; + cur->bc_ra[level] = 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_ptrs[level]--; + + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); + /* Return value means the next level up has something to do. */ + *stat = 2; + return 0; + +error0: + XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR); + 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; + + XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY); + + /* + * 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 == 0) { + for (level = 1; level < cur->bc_nlevels; level++) { + if (cur->bc_ptrs[level] == 0) { + error = xfs_btree_decrement(cur, level, &i); + if (error) + goto error0; + break; + } + } + } + + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); + *stat = i; + return 0; +error0: + XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR); + 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_ptrs[0]; + 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; +} + +/* + * 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. + */ +static int +xfs_btree_block_change_owner( + struct xfs_btree_cur *cur, + int level, + __uint64_t new_owner, + struct list_head *buffer_list) +{ + struct xfs_btree_block *block; + struct xfs_buf *bp; + union xfs_btree_ptr rptr; + + /* do right sibling readahead */ + xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA); + + /* modify the owner */ + block = xfs_btree_get_block(cur, level, &bp); + if (cur->bc_flags & XFS_BTREE_LONG_PTRS) + block->bb_u.l.bb_owner = cpu_to_be64(new_owner); + else + block->bb_u.s.bb_owner = cpu_to_be32(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) { + if (cur->bc_tp) { + xfs_trans_ordered_buf(cur->bc_tp, bp); + xfs_btree_log_block(cur, bp, XFS_BB_OWNER); + } else { + xfs_buf_delwri_queue(bp, buffer_list); + } + } else { + ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE); + ASSERT(level == cur->bc_nlevels - 1); + } + + /* 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; + + return xfs_btree_lookup_get_block(cur, level, &rptr, &block); +} + +int +xfs_btree_change_owner( + struct xfs_btree_cur *cur, + __uint64_t new_owner, + struct list_head *buffer_list) +{ + 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 */ + lptr = *ptr; + } + + /* for each buffer in the level */ + do { + error = xfs_btree_block_change_owner(cur, level, + new_owner, + buffer_list); + } while (!error); + + if (error != -ENOENT) + return error; + } + + return 0; +} |
