/* * 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_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" #include "xfs_log.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_meta_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(NULLFSBLOCK) || 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(NULLFSBLOCK) || 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_meta_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_fsblock_t bno, /* btree block disk address */ int level) /* btree block level */ { XFS_WANT_CORRUPTED_RETURN(cur->bc_mp, level > 0 && bno != NULLFSBLOCK && 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(cur->bc_mp, 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 modification was that made * it to disk. */ void xfs_btree_lblock_calc_crc( struct xfs_buf *bp) { struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp); struct xfs_buf_log_item *bip = bp->b_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) { struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp); struct xfs_mount *mp = bp->b_target->bt_mount; if (xfs_sb_version_hascrc(&mp->m_sb)) { if (!xfs_log_check_lsn(mp, be64_to_cpu(block->bb_u.l.bb_lsn))) return false; return xfs_buf_verify_cksum(bp, XFS_BTREE_LBLOCK_CRC_OFF); } return true; } /* * Calculate CRC on the whole btree block and stuff it into the * short-form btree header. * * Prior to calculting the CRC, pull the LSN out of the buffer log item and put * it into the buffer so recovery knows what the last modification was that made * it to disk. */ void xfs_btree_sblock_calc_crc( struct xfs_buf *bp) { struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp); struct xfs_buf_log_item *bip = bp->b_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) { struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp); struct xfs_mount *mp = bp->b_target->bt_mount; if (xfs_sb_version_hascrc(&mp->m_sb)) { if (!xfs_log_check_lsn(mp, be64_to_cpu(block->bb_u.s.bb_lsn))) return false; return xfs_buf_verify_cksum(bp, XFS_BTREE_SBLOCK_CRC_OFF); } return true; } static int xfs_btree_free_block( struct xfs_btree_cur *cur, struct xfs_buf *bp) { int error; error = cur->bc_ops->free_block(cur, bp); if (!error) { xfs_trans_binval(cur->bc_tp, bp); XFS_BTREE_STATS_INC(cur, free); } return error; } /* * Delete the btree cursor. */ void xfs_btree_del_cursor( 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(NULLFSBLOCK); 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_fsblock_t left = be64_to_cpu(block->bb_u.l.bb_leftsib); xfs_fsblock_t right = be64_to_cpu(block->bb_u.l.bb_rightsib); if ((lr & XFS_BTCUR_LEFTRA) && left != NULLFSBLOCK) { xfs_btree_reada_bufl(cur->bc_mp, left, 1, cur->bc_ops->buf_ops); rval++; } if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLFSBLOCK) { xfs_btree_reada_bufl(cur->bc_mp, right, 1, cur->bc_ops->buf_ops); rval++; } return rval; } STATIC int xfs_btree_readahead_sblock( struct xfs_btree_cur *cur, int lr, struct xfs_btree_block *block) { int rval = 0; xfs_agblock_t left = be32_to_cpu(block->bb_u.s.bb_leftsib); xfs_agblock_t right = be32_to_cpu(block->bb_u.s.bb_rightsib); if ((lr & XFS_BTCUR_LEFTRA) && left != NULLAGBLOCK) { xfs_btree_reada_bufs(cur->bc_mp, cur->bc_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(NULLFSBLOCK)); 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(NULLFSBLOCK)) cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA; if (b->bb_u.l.bb_rightsib == cpu_to_be64(NULLFSBLOCK)) 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(NULLFSBLOCK); 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(NULLFSBLOCK); 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(NULLFSBLOCK); buf->bb_u.l.bb_rightsib = cpu_to_be64(NULLFSBLOCK); 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_meta_uuid); buf->bb_u.l.bb_pad = 0; buf->bb_u.l.bb_lsn = 0; } } else { /* owner is a 32 bit value on short blocks */ __u32 __owner = (__u32)owner; buf->bb_u.s.bb_leftsib = cpu_to_be32(NULLAGBLOCK); buf->bb_u.s.bb_rightsib = cpu_to_be32(NULLAGBLOCK); if (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_meta_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(cur->bc_mp, 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(cur->bc_mp, 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_key *key, /* key of new block */ int *stat) { int error = 0; if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) && level == cur->bc_nlevels - 1) { struct xfs_inode *ip = cur->bc_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); *stat = 1; } else { /* A root block that needs replacing */ int logflags = 0; error = xfs_btree_new_iroot(cur, &logflags, stat); if (error || *stat == 0) return error; xfs_trans_log_inode(cur->bc_tp, ip, logflags); } return 0; } /* First, try shifting an entry to the right neighbor. */ error = xfs_btree_rshift(cur, level, stat); if (error || *stat) return error; /* Next, try shifting an entry to the left neighbor. */ error = xfs_btree_lshift(cur, level, stat); if (error) return error; if (*stat) { *oindex = *index = cur->bc_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]; return 0; } /* * Insert one record/level. Return information to the caller * allowing the next level up to proceed if necessary. */ STATIC int xfs_btree_insrec( struct xfs_btree_cur *cur, /* btree cursor */ int level, /* level to insert record at */ union xfs_btree_ptr *ptrp, /* i/o: block number inserted */ union xfs_btree_rec *rec, /* record to insert */ union xfs_btree_key *key, /* i/o: block key for ptrp */ struct xfs_btree_cur **curp, /* output: new cursor replacing cur */ int *stat) /* success/failure */ { struct xfs_btree_block *block; /* btree block */ struct xfs_buf *bp; /* buffer for block */ union xfs_btree_ptr nptr; /* new block ptr */ struct xfs_btree_cur *ncur; /* new btree cursor */ union xfs_btree_key nkey; /* new block key */ 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, &rec); 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; } 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, rec, xfs_btree_rec_addr(cur, ptr, block))); } else { ASSERT(cur->bc_ops->keys_inorder(cur, key, xfs_btree_key_addr(cur, ptr, block))); } } #endif /* * If the block is full, we can't insert the new entry until we * make the block un-full. */ xfs_btree_set_ptr_null(cur, &nptr); if (numrecs == cur->bc_ops->get_maxrecs(cur, level)) { error = xfs_btree_make_block_unfull(cur, level, numrecs, &optr, &ptr, &nptr, &ncur, &nkey, 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, rec, 1); xfs_btree_set_numrecs(block, ++numrecs); xfs_btree_log_recs(cur, bp, ptr, numrecs); #ifdef DEBUG if (ptr < numrecs) { ASSERT(cur->bc_ops->recs_inorder(cur, rp, xfs_btree_rec_addr(cur, ptr + 1, block))); } #endif } /* Log the new number of records in the btree header. */ xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS); /* If we 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, rec, ptr, LASTREC_INSREC); } /* * Return the new block number, if any. * If there is one, give back a record value and a cursor too. */ *ptrp = nptr; if (!xfs_btree_ptr_is_null(cur, &nptr)) { *key = nkey; *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_key key; /* key of block to insert */ union xfs_btree_rec rec; /* record to insert */ level = 0; ncur = NULL; pcur = cur; xfs_btree_set_ptr_null(cur, &nptr); /* Make a key out of the record data to be inserted, and save it. */ cur->bc_ops->init_rec_from_cur(cur, &rec); cur->bc_ops->init_key_from_rec(&key, &rec); /* * Loop going up the tree, starting at the leaf level. * Stop when we don't get a split block, that must mean that * the insert is finished with this level. */ do { /* * Insert nrec/nptr into this level of the tree. * Note if we fail, nptr will be null. */ error = xfs_btree_insrec(pcur, level, &nptr, &rec, &key, &ncur, &i); if (error) { if (pcur != cur) xfs_btree_del_cursor(pcur, XFS_BTREE_ERROR); goto error0; } XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, 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; int error; #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++) { 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); error = xfs_btree_free_block(cur, cbp); if (error) { XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR); return error; } 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 = xfs_btree_free_block(cur, bp); if (error) { XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR); return error; } 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(cur->bc_mp, i == 1, error0); error = xfs_btree_increment(tcur, level, &i); if (error) goto error0; XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, error0); i = xfs_btree_lastrec(tcur, level); XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, 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(cur->bc_mp, i == 1, error0); error = xfs_btree_decrement(tcur, level, &i); if (error) goto error0; XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, 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(cur->bc_mp, i == 1, error0); error = xfs_btree_decrement(tcur, level, &i); if (error) goto error0; i = xfs_btree_firstrec(tcur, level); XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, 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 = xfs_btree_free_block(cur, rbp); if (error) goto error0; /* * If we joined with the left neighbor, set the buffer in the * cursor to the left block, and fix up the index. */ if (bp != lbp) { cur->bc_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; } /** * xfs_btree_sblock_v5hdr_verify() -- verify the v5 fields of a short-format * btree block * * @bp: buffer containing the btree block * @max_recs: pointer to the m_*_mxr max records field in the xfs mount * @pag_max_level: pointer to the per-ag max level field */ bool xfs_btree_sblock_v5hdr_verify( struct xfs_buf *bp) { struct xfs_mount *mp = bp->b_target->bt_mount; struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp); struct xfs_perag *pag = bp->b_pag; if (!xfs_sb_version_hascrc(&mp->m_sb)) return false; if (!uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid)) return false; if (block->bb_u.s.bb_blkno != cpu_to_be64(bp->b_bn)) return false; if (pag && be32_to_cpu(block->bb_u.s.bb_owner) != pag->pag_agno) return false; return true; } /** * xfs_btree_sblock_verify() -- verify a short-format btree block * * @bp: buffer containing the btree block * @max_recs: maximum records allowed in this btree node */ bool xfs_btree_sblock_verify( struct xfs_buf *bp, unsigned int max_recs) { struct xfs_mount *mp = bp->b_target->bt_mount; struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp); /* numrecs verification */ if (be16_to_cpu(block->bb_numrecs) > max_recs) return false; /* sibling pointer verification */ if (!block->bb_u.s.bb_leftsib || (be32_to_cpu(block->bb_u.s.bb_leftsib) >= mp->m_sb.sb_agblocks && block->bb_u.s.bb_leftsib != cpu_to_be32(NULLAGBLOCK))) return false; if (!block->bb_u.s.bb_rightsib || (be32_to_cpu(block->bb_u.s.bb_rightsib) >= mp->m_sb.sb_agblocks && block->bb_u.s.bb_rightsib != cpu_to_be32(NULLAGBLOCK))) return false; return true; } /* * Calculate the number of btree levels needed to store a given number of * records in a short-format btree. */ uint xfs_btree_compute_maxlevels( struct xfs_mount *mp, uint *limits, unsigned long len) { uint level; unsigned long maxblocks; maxblocks = (len + limits[0] - 1) / limits[0]; for (level = 1; maxblocks > 1; level++) maxblocks = (maxblocks + limits[1] - 1) / limits[1]; return level; }