v4.19.13 snapshot.
diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c
new file mode 100644
index 0000000..34c6d7b
--- /dev/null
+++ b/fs/xfs/libxfs/xfs_btree.c
@@ -0,0 +1,4947 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
+ * All Rights Reserved.
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_log_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_bit.h"
+#include "xfs_mount.h"
+#include "xfs_defer.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_errortag.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, 0, XFS_BMAP_MAGIC, XFS_IBT_MAGIC,
+ XFS_FIBT_MAGIC, 0 },
+ { XFS_ABTB_CRC_MAGIC, XFS_ABTC_CRC_MAGIC, XFS_RMAP_CRC_MAGIC,
+ XFS_BMAP_CRC_MAGIC, XFS_IBT_CRC_MAGIC, XFS_FIBT_CRC_MAGIC,
+ XFS_REFC_CRC_MAGIC }
+};
+
+uint32_t
+xfs_btree_magic(
+ int crc,
+ xfs_btnum_t btnum)
+{
+ uint32_t magic = xfs_magics[crc][btnum];
+
+ /* Ensure we asked for crc for crc-only magics. */
+ ASSERT(magic != 0);
+ return magic;
+}
+
+/*
+ * Check a long btree block header. Return the address of the failing check,
+ * or NULL if everything is ok.
+ */
+xfs_failaddr_t
+__xfs_btree_check_lblock(
+ struct xfs_btree_cur *cur,
+ struct xfs_btree_block *block,
+ int level,
+ struct xfs_buf *bp)
+{
+ struct xfs_mount *mp = cur->bc_mp;
+ xfs_btnum_t btnum = cur->bc_btnum;
+ int crc = xfs_sb_version_hascrc(&mp->m_sb);
+
+ if (crc) {
+ if (!uuid_equal(&block->bb_u.l.bb_uuid, &mp->m_sb.sb_meta_uuid))
+ return __this_address;
+ if (block->bb_u.l.bb_blkno !=
+ cpu_to_be64(bp ? bp->b_bn : XFS_BUF_DADDR_NULL))
+ return __this_address;
+ if (block->bb_u.l.bb_pad != cpu_to_be32(0))
+ return __this_address;
+ }
+
+ if (be32_to_cpu(block->bb_magic) != xfs_btree_magic(crc, btnum))
+ return __this_address;
+ if (be16_to_cpu(block->bb_level) != level)
+ return __this_address;
+ if (be16_to_cpu(block->bb_numrecs) >
+ cur->bc_ops->get_maxrecs(cur, level))
+ return __this_address;
+ if (block->bb_u.l.bb_leftsib != cpu_to_be64(NULLFSBLOCK) &&
+ !xfs_btree_check_lptr(cur, be64_to_cpu(block->bb_u.l.bb_leftsib),
+ level + 1))
+ return __this_address;
+ if (block->bb_u.l.bb_rightsib != cpu_to_be64(NULLFSBLOCK) &&
+ !xfs_btree_check_lptr(cur, be64_to_cpu(block->bb_u.l.bb_rightsib),
+ level + 1))
+ return __this_address;
+
+ return NULL;
+}
+
+/* Check a long btree block header. */
+static int
+xfs_btree_check_lblock(
+ struct xfs_btree_cur *cur,
+ struct xfs_btree_block *block,
+ int level,
+ struct xfs_buf *bp)
+{
+ struct xfs_mount *mp = cur->bc_mp;
+ xfs_failaddr_t fa;
+
+ fa = __xfs_btree_check_lblock(cur, block, level, bp);
+ if (unlikely(XFS_TEST_ERROR(fa != NULL, mp,
+ XFS_ERRTAG_BTREE_CHECK_LBLOCK))) {
+ if (bp)
+ trace_xfs_btree_corrupt(bp, _RET_IP_);
+ XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, mp);
+ return -EFSCORRUPTED;
+ }
+ return 0;
+}
+
+/*
+ * Check a short btree block header. Return the address of the failing check,
+ * or NULL if everything is ok.
+ */
+xfs_failaddr_t
+__xfs_btree_check_sblock(
+ struct xfs_btree_cur *cur,
+ struct xfs_btree_block *block,
+ int level,
+ struct xfs_buf *bp)
+{
+ struct xfs_mount *mp = cur->bc_mp;
+ xfs_btnum_t btnum = cur->bc_btnum;
+ int crc = xfs_sb_version_hascrc(&mp->m_sb);
+
+ if (crc) {
+ if (!uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid))
+ return __this_address;
+ if (block->bb_u.s.bb_blkno !=
+ cpu_to_be64(bp ? bp->b_bn : XFS_BUF_DADDR_NULL))
+ return __this_address;
+ }
+
+ if (be32_to_cpu(block->bb_magic) != xfs_btree_magic(crc, btnum))
+ return __this_address;
+ if (be16_to_cpu(block->bb_level) != level)
+ return __this_address;
+ if (be16_to_cpu(block->bb_numrecs) >
+ cur->bc_ops->get_maxrecs(cur, level))
+ return __this_address;
+ if (block->bb_u.s.bb_leftsib != cpu_to_be32(NULLAGBLOCK) &&
+ !xfs_btree_check_sptr(cur, be32_to_cpu(block->bb_u.s.bb_leftsib),
+ level + 1))
+ return __this_address;
+ if (block->bb_u.s.bb_rightsib != cpu_to_be32(NULLAGBLOCK) &&
+ !xfs_btree_check_sptr(cur, be32_to_cpu(block->bb_u.s.bb_rightsib),
+ level + 1))
+ return __this_address;
+
+ return NULL;
+}
+
+/* Check a short btree block header. */
+STATIC int
+xfs_btree_check_sblock(
+ struct xfs_btree_cur *cur,
+ struct xfs_btree_block *block,
+ int level,
+ struct xfs_buf *bp)
+{
+ struct xfs_mount *mp = cur->bc_mp;
+ xfs_failaddr_t fa;
+
+ fa = __xfs_btree_check_sblock(cur, block, level, bp);
+ if (unlikely(XFS_TEST_ERROR(fa != NULL, mp,
+ XFS_ERRTAG_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 this long pointer is valid and points within the fs. */
+bool
+xfs_btree_check_lptr(
+ struct xfs_btree_cur *cur,
+ xfs_fsblock_t fsbno,
+ int level)
+{
+ if (level <= 0)
+ return false;
+ return xfs_verify_fsbno(cur->bc_mp, fsbno);
+}
+
+/* Check that this short pointer is valid and points within the AG. */
+bool
+xfs_btree_check_sptr(
+ struct xfs_btree_cur *cur,
+ xfs_agblock_t agbno,
+ int level)
+{
+ if (level <= 0)
+ return false;
+ return xfs_verify_agbno(cur->bc_mp, cur->bc_private.a.agno, agbno);
+}
+
+/*
+ * Check that a given (indexed) btree pointer at a certain level of a
+ * btree is valid and doesn't point past where it should.
+ */
+static int
+xfs_btree_check_ptr(
+ struct xfs_btree_cur *cur,
+ union xfs_btree_ptr *ptr,
+ int index,
+ int level)
+{
+ if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
+ if (xfs_btree_check_lptr(cur, be64_to_cpu((&ptr->l)[index]),
+ level))
+ return 0;
+ xfs_err(cur->bc_mp,
+"Inode %llu fork %d: Corrupt btree %d pointer at level %d index %d.",
+ cur->bc_private.b.ip->i_ino,
+ cur->bc_private.b.whichfork, cur->bc_btnum,
+ level, index);
+ } else {
+ if (xfs_btree_check_sptr(cur, be32_to_cpu((&ptr->s)[index]),
+ level))
+ return 0;
+ xfs_err(cur->bc_mp,
+"AG %u: Corrupt btree %d pointer at level %d index %d.",
+ cur->bc_private.a.agno, cur->bc_btnum,
+ level, index);
+ }
+
+ return -EFSCORRUPTED;
+}
+
+#ifdef DEBUG
+# define xfs_btree_debug_check_ptr xfs_btree_check_ptr
+#else
+# define xfs_btree_debug_check_ptr(...) (0)
+#endif
+
+/*
+ * Calculate CRC on the whole btree block and stuff it into the
+ * long-form btree header.
+ *
+ * Prior to calculting the CRC, pull the LSN out of the buffer log item and put
+ * it into the buffer so recovery knows what the last modification was that made
+ * it to disk.
+ */
+void
+xfs_btree_lblock_calc_crc(
+ struct xfs_buf *bp)
+{
+ struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
+ struct xfs_buf_log_item *bip = bp->b_log_item;
+
+ if (!xfs_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_log_item;
+
+ 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 __this_address;
+ 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!
+ *
+ * If XFS_BTREE_OVERLAPPING is set, then this btree supports keys containing
+ * overlapping intervals. In such a tree, records are still sorted lowest to
+ * highest and indexed by the smallest key value that refers to the record.
+ * However, nodes are different: each pointer has two associated keys -- one
+ * indexing the lowest key available in the block(s) below (the same behavior
+ * as the key in a regular btree) and another indexing the highest key
+ * available in the block(s) below. Because records are /not/ sorted by the
+ * highest key, all leaf block updates require us to compute the highest key
+ * that matches any record in the leaf and to recursively update the high keys
+ * in the nodes going further up in the tree, if necessary. Nodes look like
+ * this:
+ *
+ * +--------+-----+-----+-----+-----+-----+-------+-------+-----+
+ * Non-Leaf: | header | lo1 | hi1 | lo2 | hi2 | ... | ptr 1 | ptr 2 | ... |
+ * +--------+-----+-----+-----+-----+-----+-------+-------+-----+
+ *
+ * To perform an interval query on an overlapped tree, perform the usual
+ * depth-first search and use the low and high keys to decide if we can skip
+ * that particular node. If a leaf node is reached, return the records that
+ * intersect the interval. Note that an interval query may return numerous
+ * entries. For a non-overlapped tree, simply search for the record associated
+ * with the lowest key and iterate forward until a non-matching record is
+ * found. Section 14.3 ("Interval Trees") of _Introduction to Algorithms_ by
+ * Cormen, Leiserson, Rivest, and Stein (2nd or 3rd ed. only) discuss this in
+ * more detail.
+ *
+ * Why do we care about overlapping intervals? Let's say you have a bunch of
+ * reverse mapping records on a reflink filesystem:
+ *
+ * 1: +- file A startblock B offset C length D -----------+
+ * 2: +- file E startblock F offset G length H --------------+
+ * 3: +- file I startblock F offset J length K --+
+ * 4: +- file L... --+
+ *
+ * Now say we want to map block (B+D) into file A at offset (C+D). Ideally,
+ * we'd simply increment the length of record 1. But how do we find the record
+ * that ends at (B+D-1) (i.e. record 1)? A LE lookup of (B+D-1) would return
+ * record 3 because the keys are ordered first by startblock. An interval
+ * query would return records 1 and 2 because they both overlap (B+D-1), and
+ * from that we can pick out record 1 as the appropriate left neighbor.
+ *
+ * In the non-overlapped case you can do a LE lookup and decrement the cursor
+ * because a record's interval must end before the next record.
+ */
+
+/*
+ * Return size of the btree block header for this btree instance.
+ */
+static inline size_t xfs_btree_block_len(struct xfs_btree_cur *cur)
+{
+ if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
+ if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS)
+ return XFS_BTREE_LBLOCK_CRC_LEN;
+ return XFS_BTREE_LBLOCK_LEN;
+ }
+ if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS)
+ return XFS_BTREE_SBLOCK_CRC_LEN;
+ return XFS_BTREE_SBLOCK_LEN;
+}
+
+/*
+ * Return size of btree block pointers for this btree instance.
+ */
+static inline size_t xfs_btree_ptr_len(struct xfs_btree_cur *cur)
+{
+ return (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
+ sizeof(__be64) : sizeof(__be32);
+}
+
+/*
+ * Calculate offset of the n-th record in a btree block.
+ */
+STATIC size_t
+xfs_btree_rec_offset(
+ struct xfs_btree_cur *cur,
+ int n)
+{
+ return xfs_btree_block_len(cur) +
+ (n - 1) * cur->bc_ops->rec_len;
+}
+
+/*
+ * Calculate offset of the n-th key in a btree block.
+ */
+STATIC size_t
+xfs_btree_key_offset(
+ struct xfs_btree_cur *cur,
+ int n)
+{
+ return xfs_btree_block_len(cur) +
+ (n - 1) * cur->bc_ops->key_len;
+}
+
+/*
+ * Calculate offset of the n-th high key in a btree block.
+ */
+STATIC size_t
+xfs_btree_high_key_offset(
+ struct xfs_btree_cur *cur,
+ int n)
+{
+ return xfs_btree_block_len(cur) +
+ (n - 1) * cur->bc_ops->key_len + (cur->bc_ops->key_len / 2);
+}
+
+/*
+ * Calculate offset of the n-th block pointer in a btree block.
+ */
+STATIC size_t
+xfs_btree_ptr_offset(
+ struct xfs_btree_cur *cur,
+ int n,
+ int level)
+{
+ return xfs_btree_block_len(cur) +
+ cur->bc_ops->get_maxrecs(cur, level) * cur->bc_ops->key_len +
+ (n - 1) * xfs_btree_ptr_len(cur);
+}
+
+/*
+ * Return a pointer to the n-th record in the btree block.
+ */
+union xfs_btree_rec *
+xfs_btree_rec_addr(
+ struct xfs_btree_cur *cur,
+ int n,
+ struct xfs_btree_block *block)
+{
+ return (union xfs_btree_rec *)
+ ((char *)block + xfs_btree_rec_offset(cur, n));
+}
+
+/*
+ * Return a pointer to the n-th key in the btree block.
+ */
+union xfs_btree_key *
+xfs_btree_key_addr(
+ struct xfs_btree_cur *cur,
+ int n,
+ struct xfs_btree_block *block)
+{
+ return (union xfs_btree_key *)
+ ((char *)block + xfs_btree_key_offset(cur, n));
+}
+
+/*
+ * Return a pointer to the n-th high key in the btree block.
+ */
+union xfs_btree_key *
+xfs_btree_high_key_addr(
+ struct xfs_btree_cur *cur,
+ int n,
+ struct xfs_btree_block *block)
+{
+ return (union xfs_btree_key *)
+ ((char *)block + xfs_btree_high_key_offset(cur, n));
+}
+
+/*
+ * Return a pointer to the n-th block pointer in the btree block.
+ */
+union xfs_btree_ptr *
+xfs_btree_ptr_addr(
+ struct xfs_btree_cur *cur,
+ int n,
+ struct xfs_btree_block *block)
+{
+ int level = xfs_btree_get_level(block);
+
+ ASSERT(block->bb_level != 0);
+
+ return (union xfs_btree_ptr *)
+ ((char *)block + xfs_btree_ptr_offset(cur, n, level));
+}
+
+/*
+ * 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.
+ */
+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);
+ if (xfs_btree_check_block(cur, block, level, bp))
+ return 0;
+ /*
+ * It's empty, there is no such record.
+ */
+ if (!block->bb_numrecs)
+ return 0;
+ /*
+ * Set the ptr value to 1, that's the first record/key.
+ */
+ cur->bc_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);
+ if (xfs_btree_check_block(cur, block, level, bp))
+ return 0;
+ /*
+ * It's empty, there is no such record.
+ */
+ if (!block->bb_numrecs)
+ return 0;
+ /*
+ * Set the ptr value to numrecs, that's the last record/key.
+ */
+ cur->bc_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;
+
+ if (!xfs_verify_fsbno(mp, fsbno))
+ return -EFSCORRUPTED;
+ d = XFS_FSB_TO_DADDR(mp, fsbno);
+ error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, d,
+ mp->m_bsize, 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 int
+xfs_btree_ptr_to_daddr(
+ struct xfs_btree_cur *cur,
+ union xfs_btree_ptr *ptr,
+ xfs_daddr_t *daddr)
+{
+ xfs_fsblock_t fsbno;
+ xfs_agblock_t agbno;
+ int error;
+
+ error = xfs_btree_check_ptr(cur, ptr, 0, 1);
+ if (error)
+ return error;
+
+ if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
+ fsbno = be64_to_cpu(ptr->l);
+ *daddr = XFS_FSB_TO_DADDR(cur->bc_mp, fsbno);
+ } else {
+ agbno = be32_to_cpu(ptr->s);
+ *daddr = XFS_AGB_TO_DADDR(cur->bc_mp, cur->bc_private.a.agno,
+ agbno);
+ }
+
+ return 0;
+}
+
+/*
+ * Readahead @count btree blocks at the given @ptr location.
+ *
+ * We don't need to care about long or short form btrees here as we have a
+ * method of converting the ptr directly to a daddr available to us.
+ */
+STATIC void
+xfs_btree_readahead_ptr(
+ struct xfs_btree_cur *cur,
+ union xfs_btree_ptr *ptr,
+ xfs_extlen_t count)
+{
+ xfs_daddr_t daddr;
+
+ if (xfs_btree_ptr_to_daddr(cur, ptr, &daddr))
+ return;
+ xfs_buf_readahead(cur->bc_mp->m_ddev_targp, daddr,
+ cur->bc_mp->m_bsize * count, cur->bc_ops->buf_ops);
+}
+
+/*
+ * Set the buffer for level "lev" in the cursor to bp, releasing
+ * any previous buffer.
+ */
+STATIC void
+xfs_btree_setbuf(
+ 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;
+ }
+}
+
+bool
+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
+ */
+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,
+ xfs_btnum_t btnum,
+ __u16 level,
+ __u16 numrecs,
+ __u64 owner,
+ unsigned int flags)
+{
+ int crc = xfs_sb_version_hascrc(&mp->m_sb);
+ __u32 magic = xfs_btree_magic(crc, btnum);
+
+ buf->bb_magic = cpu_to_be32(magic);
+ buf->bb_level = cpu_to_be16(level);
+ buf->bb_numrecs = cpu_to_be16(numrecs);
+
+ if (flags & XFS_BTREE_LONG_PTRS) {
+ buf->bb_u.l.bb_leftsib = cpu_to_be64(NULLFSBLOCK);
+ buf->bb_u.l.bb_rightsib = cpu_to_be64(NULLFSBLOCK);
+ if (crc) {
+ buf->bb_u.l.bb_blkno = cpu_to_be64(blkno);
+ buf->bb_u.l.bb_owner = cpu_to_be64(owner);
+ uuid_copy(&buf->bb_u.l.bb_uuid, &mp->m_sb.sb_meta_uuid);
+ buf->bb_u.l.bb_pad = 0;
+ buf->bb_u.l.bb_lsn = 0;
+ }
+ } else {
+ /* owner is a 32 bit value on short blocks */
+ __u32 __owner = (__u32)owner;
+
+ buf->bb_u.s.bb_leftsib = cpu_to_be32(NULLAGBLOCK);
+ buf->bb_u.s.bb_rightsib = cpu_to_be32(NULLAGBLOCK);
+ if (crc) {
+ buf->bb_u.s.bb_blkno = cpu_to_be64(blkno);
+ buf->bb_u.s.bb_owner = cpu_to_be32(__owner);
+ uuid_copy(&buf->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid);
+ buf->bb_u.s.bb_lsn = 0;
+ }
+ }
+}
+
+void
+xfs_btree_init_block(
+ struct xfs_mount *mp,
+ struct xfs_buf *bp,
+ xfs_btnum_t btnum,
+ __u16 level,
+ __u16 numrecs,
+ __u64 owner,
+ unsigned int flags)
+{
+ xfs_btree_init_block_int(mp, XFS_BUF_TO_BLOCK(bp), bp->b_bn,
+ btnum, 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,
+ cur->bc_btnum, level, numrecs,
+ owner, cur->bc_flags);
+}
+
+/*
+ * Return true if ptr is the last record in the btree and
+ * we need to track updates to this record. The decision
+ * will be further refined in the update_lastrec method.
+ */
+STATIC int
+xfs_btree_is_lastrec(
+ struct xfs_btree_cur *cur,
+ struct xfs_btree_block *block,
+ int level)
+{
+ union xfs_btree_ptr ptr;
+
+ if (level > 0)
+ return 0;
+ if (!(cur->bc_flags & XFS_BTREE_LASTREC_UPDATE))
+ return 0;
+
+ xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
+ if (!xfs_btree_ptr_is_null(cur, &ptr))
+ return 0;
+ return 1;
+}
+
+STATIC void
+xfs_btree_buf_to_ptr(
+ struct xfs_btree_cur *cur,
+ struct xfs_buf *bp,
+ union xfs_btree_ptr *ptr)
+{
+ if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
+ ptr->l = cpu_to_be64(XFS_DADDR_TO_FSB(cur->bc_mp,
+ XFS_BUF_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;
+ case XFS_BTNUM_RMAP:
+ xfs_buf_set_ref(bp, XFS_RMAP_BTREE_REF);
+ break;
+ case XFS_BTNUM_REFC:
+ xfs_buf_set_ref(bp, XFS_REFC_BTREE_REF);
+ break;
+ default:
+ ASSERT(0);
+ }
+}
+
+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;
+ int error;
+
+ /* need to sort out how callers deal with failures first */
+ ASSERT(!(flags & XBF_TRYLOCK));
+
+ error = xfs_btree_ptr_to_daddr(cur, ptr, &d);
+ if (error)
+ return error;
+ *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));
+
+ error = xfs_btree_ptr_to_daddr(cur, ptr, &d);
+ if (error)
+ return error;
+ error = xfs_trans_read_buf(mp, cur->bc_tp, mp->m_ddev_targp, d,
+ mp->m_bsize, flags, bpp,
+ cur->bc_ops->buf_ops);
+ if (error)
+ return error;
+
+ xfs_btree_set_refs(cur, *bpp);
+ *block = XFS_BUF_TO_BLOCK(*bpp);
+ return 0;
+}
+
+/*
+ * Copy keys from one btree block to another.
+ */
+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)
+{
+
+ 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));
+ }
+}
+
+/*
+ * Log record values from the btree block.
+ */
+void
+xfs_btree_log_recs(
+ struct xfs_btree_cur *cur,
+ struct xfs_buf *bp,
+ int first,
+ int last)
+{
+
+ xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
+ xfs_trans_log_buf(cur->bc_tp, bp,
+ xfs_btree_rec_offset(cur, first),
+ xfs_btree_rec_offset(cur, last + 1) - 1);
+
+}
+
+/*
+ * Log block pointer fields from a btree block (nonleaf).
+ */
+STATIC void
+xfs_btree_log_ptrs(
+ struct xfs_btree_cur *cur, /* btree cursor */
+ struct xfs_buf *bp, /* buffer containing btree block */
+ int first, /* index of first pointer to log */
+ int last) /* index of last pointer to log */
+{
+
+ if (bp) {
+ struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
+ int level = xfs_btree_get_level(block);
+
+ xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
+ xfs_trans_log_buf(cur->bc_tp, bp,
+ xfs_btree_ptr_offset(cur, first, level),
+ xfs_btree_ptr_offset(cur, last + 1, level) - 1);
+ } else {
+ xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
+ xfs_ilog_fbroot(cur->bc_private.b.whichfork));
+ }
+
+}
+
+/*
+ * Log fields from a btree block header.
+ */
+void
+xfs_btree_log_block(
+ struct xfs_btree_cur *cur, /* btree cursor */
+ struct xfs_buf *bp, /* buffer containing btree block */
+ 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
+ };
+
+ 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));
+ }
+}
+
+/*
+ * Increment cursor by one record at the level.
+ * For nonzero levels the leaf-ward information is untouched.
+ */
+int /* error */
+xfs_btree_increment(
+ struct xfs_btree_cur *cur,
+ int level,
+ int *stat) /* success/failure */
+{
+ struct xfs_btree_block *block;
+ union xfs_btree_ptr ptr;
+ struct xfs_buf *bp;
+ int error; /* error return value */
+ int lev;
+
+ ASSERT(level < cur->bc_nlevels);
+
+ /* Read-ahead to the right at this level. */
+ xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA);
+
+ /* Get a pointer to the btree block. */
+ block = xfs_btree_get_block(cur, level, &bp);
+
+#ifdef DEBUG
+ error = xfs_btree_check_block(cur, block, level, bp);
+ if (error)
+ goto error0;
+#endif
+
+ /* We're done if we remain in the block after the increment. */
+ if (++cur->bc_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:
+ *stat = 1;
+ return 0;
+
+out0:
+ *stat = 0;
+ return 0;
+
+error0:
+ return error;
+}
+
+/*
+ * Decrement cursor by one record at the level.
+ * For nonzero levels the leaf-ward information is untouched.
+ */
+int /* error */
+xfs_btree_decrement(
+ struct xfs_btree_cur *cur,
+ int level,
+ int *stat) /* success/failure */
+{
+ struct xfs_btree_block *block;
+ xfs_buf_t *bp;
+ int error; /* error return value */
+ int lev;
+ union xfs_btree_ptr ptr;
+
+ ASSERT(level < cur->bc_nlevels);
+
+ /* Read-ahead to the left at this level. */
+ xfs_btree_readahead(cur, level, XFS_BTCUR_LEFTRA);
+
+ /* We're done if we remain in the block after the decrement. */
+ if (--cur->bc_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:
+ *stat = 1;
+ return 0;
+
+out0:
+ *stat = 0;
+ return 0;
+
+error0:
+ return error;
+}
+
+int
+xfs_btree_lookup_get_block(
+ struct xfs_btree_cur *cur, /* btree cursor */
+ int level, /* level in the btree */
+ union xfs_btree_ptr *pp, /* ptr to btree block */
+ struct xfs_btree_block **blkp) /* return btree block */
+{
+ struct xfs_buf *bp; /* buffer pointer for btree block */
+ xfs_daddr_t daddr;
+ int error = 0;
+
+ /* special case the root block if in an inode */
+ if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
+ (level == cur->bc_nlevels - 1)) {
+ *blkp = xfs_btree_get_iroot(cur);
+ return 0;
+ }
+
+ /*
+ * If the old buffer at this level for the disk address we are
+ * looking for re-use it.
+ *
+ * Otherwise throw it away and get a new one.
+ */
+ bp = cur->bc_bufs[level];
+ error = xfs_btree_ptr_to_daddr(cur, pp, &daddr);
+ if (error)
+ return error;
+ if (bp && XFS_BUF_ADDR(bp) == daddr) {
+ *blkp = XFS_BUF_TO_BLOCK(bp);
+ return 0;
+ }
+
+ error = xfs_btree_read_buf_block(cur, pp, 0, blkp, &bp);
+ if (error)
+ return error;
+
+ /* Check the inode owner since the verifiers don't. */
+ if (xfs_sb_version_hascrc(&cur->bc_mp->m_sb) &&
+ !(cur->bc_private.b.flags & XFS_BTCUR_BPRV_INVALID_OWNER) &&
+ (cur->bc_flags & XFS_BTREE_LONG_PTRS) &&
+ be64_to_cpu((*blkp)->bb_u.l.bb_owner) !=
+ cur->bc_private.b.ip->i_ino)
+ goto out_bad;
+
+ /* Did we get the level we were looking for? */
+ if (be16_to_cpu((*blkp)->bb_level) != level)
+ goto out_bad;
+
+ /* Check that internal nodes have at least one record. */
+ if (level != 0 && be16_to_cpu((*blkp)->bb_numrecs) == 0)
+ goto out_bad;
+
+ xfs_btree_setbuf(cur, level, bp);
+ return 0;
+
+out_bad:
+ *blkp = NULL;
+ xfs_trans_brelse(cur->bc_tp, bp);
+ return -EFSCORRUPTED;
+}
+
+/*
+ * Get current search key. For level 0 we don't actually have a key
+ * structure so we make one up from the record. For all other levels
+ * we just return the right key.
+ */
+STATIC union xfs_btree_key *
+xfs_lookup_get_search_key(
+ struct xfs_btree_cur *cur,
+ int level,
+ int keyno,
+ struct xfs_btree_block *block,
+ union xfs_btree_key *kp)
+{
+ if (level == 0) {
+ cur->bc_ops->init_key_from_rec(kp,
+ xfs_btree_rec_addr(cur, keyno, block));
+ return kp;
+ }
+
+ return xfs_btree_key_addr(cur, keyno, block);
+}
+
+/*
+ * Lookup the record. The cursor is made to point to it, based on dir.
+ * stat is set to 0 if can't find any such record, 1 for success.
+ */
+int /* error */
+xfs_btree_lookup(
+ struct xfs_btree_cur *cur, /* btree cursor */
+ xfs_lookup_t dir, /* <=, ==, or >= */
+ int *stat) /* success/failure */
+{
+ struct xfs_btree_block *block; /* current btree block */
+ int64_t diff; /* difference for the current key */
+ int error; /* error return value */
+ int keyno; /* current key number */
+ int level; /* level in the btree */
+ union xfs_btree_ptr *pp; /* ptr to btree block */
+ union xfs_btree_ptr ptr; /* ptr to btree block */
+
+ XFS_BTREE_STATS_INC(cur, lookup);
+
+ /* No such thing as a zero-level tree. */
+ if (cur->bc_nlevels == 0)
+ return -EFSCORRUPTED;
+
+ block = NULL;
+ keyno = 0;
+
+ /* initialise start pointer from cursor */
+ cur->bc_ops->init_ptr_from_cur(cur, &ptr);
+ pp = &ptr;
+
+ /*
+ * Iterate over each level in the btree, starting at the root.
+ * For each level above the leaves, find the key we need, based
+ * on the lookup record, then follow the corresponding block
+ * pointer down to the next level.
+ */
+ for (level = cur->bc_nlevels - 1, diff = 1; level >= 0; level--) {
+ /* Get the block we need to do the lookup on. */
+ error = xfs_btree_lookup_get_block(cur, level, pp, &block);
+ if (error)
+ goto error0;
+
+ if (diff == 0) {
+ /*
+ * If we already had a key match at a higher level, we
+ * know we need to use the first entry in this block.
+ */
+ keyno = 1;
+ } else {
+ /* Otherwise search this block. Do a binary search. */
+
+ int high; /* high entry number */
+ int low; /* low entry number */
+
+ /* Set low and high entry numbers, 1-based. */
+ low = 1;
+ high = xfs_btree_get_numrecs(block);
+ if (!high) {
+ /* Block is empty, must be an empty leaf. */
+ if (level != 0 || cur->bc_nlevels != 1) {
+ XFS_CORRUPTION_ERROR(__func__,
+ XFS_ERRLEVEL_LOW,
+ cur->bc_mp, block,
+ sizeof(*block));
+ return -EFSCORRUPTED;
+ }
+
+ cur->bc_ptrs[0] = dir != XFS_LOOKUP_LE;
+ *stat = 0;
+ return 0;
+ }
+
+ /* Binary search the block. */
+ while (low <= high) {
+ union xfs_btree_key key;
+ union xfs_btree_key *kp;
+
+ XFS_BTREE_STATS_INC(cur, compare);
+
+ /* keyno is average of low and high. */
+ keyno = (low + high) >> 1;
+
+ /* Get current search key */
+ kp = xfs_lookup_get_search_key(cur, level,
+ keyno, block, &key);
+
+ /*
+ * Compute difference to get next direction:
+ * - less than, move right
+ * - greater than, move left
+ * - equal, we're done
+ */
+ diff = cur->bc_ops->key_diff(cur, kp);
+ if (diff < 0)
+ low = keyno + 1;
+ else if (diff > 0)
+ high = keyno - 1;
+ else
+ break;
+ }
+ }
+
+ /*
+ * If there are more levels, set up for the next level
+ * by getting the block number and filling in the cursor.
+ */
+ if (level > 0) {
+ /*
+ * If we moved left, need the previous key number,
+ * unless there isn't one.
+ */
+ if (diff > 0 && --keyno < 1)
+ keyno = 1;
+ pp = xfs_btree_ptr_addr(cur, keyno, block);
+
+ error = xfs_btree_debug_check_ptr(cur, pp, 0, level);
+ if (error)
+ goto error0;
+
+ cur->bc_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);
+ *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;
+ return 0;
+
+error0:
+ return error;
+}
+
+/* Find the high key storage area from a regular key. */
+union xfs_btree_key *
+xfs_btree_high_key_from_key(
+ struct xfs_btree_cur *cur,
+ union xfs_btree_key *key)
+{
+ ASSERT(cur->bc_flags & XFS_BTREE_OVERLAPPING);
+ return (union xfs_btree_key *)((char *)key +
+ (cur->bc_ops->key_len / 2));
+}
+
+/* Determine the low (and high if overlapped) keys of a leaf block */
+STATIC void
+xfs_btree_get_leaf_keys(
+ struct xfs_btree_cur *cur,
+ struct xfs_btree_block *block,
+ union xfs_btree_key *key)
+{
+ union xfs_btree_key max_hkey;
+ union xfs_btree_key hkey;
+ union xfs_btree_rec *rec;
+ union xfs_btree_key *high;
+ int n;
+
+ rec = xfs_btree_rec_addr(cur, 1, block);
+ cur->bc_ops->init_key_from_rec(key, rec);
+
+ if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
+
+ cur->bc_ops->init_high_key_from_rec(&max_hkey, rec);
+ for (n = 2; n <= xfs_btree_get_numrecs(block); n++) {
+ rec = xfs_btree_rec_addr(cur, n, block);
+ cur->bc_ops->init_high_key_from_rec(&hkey, rec);
+ if (cur->bc_ops->diff_two_keys(cur, &hkey, &max_hkey)
+ > 0)
+ max_hkey = hkey;
+ }
+
+ high = xfs_btree_high_key_from_key(cur, key);
+ memcpy(high, &max_hkey, cur->bc_ops->key_len / 2);
+ }
+}
+
+/* Determine the low (and high if overlapped) keys of a node block */
+STATIC void
+xfs_btree_get_node_keys(
+ struct xfs_btree_cur *cur,
+ struct xfs_btree_block *block,
+ union xfs_btree_key *key)
+{
+ union xfs_btree_key *hkey;
+ union xfs_btree_key *max_hkey;
+ union xfs_btree_key *high;
+ int n;
+
+ if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
+ memcpy(key, xfs_btree_key_addr(cur, 1, block),
+ cur->bc_ops->key_len / 2);
+
+ max_hkey = xfs_btree_high_key_addr(cur, 1, block);
+ for (n = 2; n <= xfs_btree_get_numrecs(block); n++) {
+ hkey = xfs_btree_high_key_addr(cur, n, block);
+ if (cur->bc_ops->diff_two_keys(cur, hkey, max_hkey) > 0)
+ max_hkey = hkey;
+ }
+
+ high = xfs_btree_high_key_from_key(cur, key);
+ memcpy(high, max_hkey, cur->bc_ops->key_len / 2);
+ } else {
+ memcpy(key, xfs_btree_key_addr(cur, 1, block),
+ cur->bc_ops->key_len);
+ }
+}
+
+/* Derive the keys for any btree block. */
+void
+xfs_btree_get_keys(
+ struct xfs_btree_cur *cur,
+ struct xfs_btree_block *block,
+ union xfs_btree_key *key)
+{
+ if (be16_to_cpu(block->bb_level) == 0)
+ xfs_btree_get_leaf_keys(cur, block, key);
+ else
+ xfs_btree_get_node_keys(cur, block, key);
+}
+
+/*
+ * Decide if we need to update the parent keys of a btree block. For
+ * a standard btree this is only necessary if we're updating the first
+ * record/key. For an overlapping btree, we must always update the
+ * keys because the highest key can be in any of the records or keys
+ * in the block.
+ */
+static inline bool
+xfs_btree_needs_key_update(
+ struct xfs_btree_cur *cur,
+ int ptr)
+{
+ return (cur->bc_flags & XFS_BTREE_OVERLAPPING) || ptr == 1;
+}
+
+/*
+ * Update the low and high parent keys of the given level, progressing
+ * towards the root. If force_all is false, stop if the keys for a given
+ * level do not need updating.
+ */
+STATIC int
+__xfs_btree_updkeys(
+ struct xfs_btree_cur *cur,
+ int level,
+ struct xfs_btree_block *block,
+ struct xfs_buf *bp0,
+ bool force_all)
+{
+ union xfs_btree_key key; /* keys from current level */
+ union xfs_btree_key *lkey; /* keys from the next level up */
+ union xfs_btree_key *hkey;
+ union xfs_btree_key *nlkey; /* keys from the next level up */
+ union xfs_btree_key *nhkey;
+ struct xfs_buf *bp;
+ int ptr;
+
+ ASSERT(cur->bc_flags & XFS_BTREE_OVERLAPPING);
+
+ /* Exit if there aren't any parent levels to update. */
+ if (level + 1 >= cur->bc_nlevels)
+ return 0;
+
+ trace_xfs_btree_updkeys(cur, level, bp0);
+
+ lkey = &key;
+ hkey = xfs_btree_high_key_from_key(cur, lkey);
+ xfs_btree_get_keys(cur, block, lkey);
+ for (level++; level < cur->bc_nlevels; level++) {
+#ifdef DEBUG
+ int error;
+#endif
+ block = xfs_btree_get_block(cur, level, &bp);
+ trace_xfs_btree_updkeys(cur, level, bp);
+#ifdef DEBUG
+ error = xfs_btree_check_block(cur, block, level, bp);
+ if (error)
+ return error;
+#endif
+ ptr = cur->bc_ptrs[level];
+ nlkey = xfs_btree_key_addr(cur, ptr, block);
+ nhkey = xfs_btree_high_key_addr(cur, ptr, block);
+ if (!force_all &&
+ !(cur->bc_ops->diff_two_keys(cur, nlkey, lkey) != 0 ||
+ cur->bc_ops->diff_two_keys(cur, nhkey, hkey) != 0))
+ break;
+ xfs_btree_copy_keys(cur, nlkey, lkey, 1);
+ xfs_btree_log_keys(cur, bp, ptr, ptr);
+ if (level + 1 >= cur->bc_nlevels)
+ break;
+ xfs_btree_get_node_keys(cur, block, lkey);
+ }
+
+ return 0;
+}
+
+/* Update all the keys from some level in cursor back to the root. */
+STATIC int
+xfs_btree_updkeys_force(
+ struct xfs_btree_cur *cur,
+ int level)
+{
+ struct xfs_buf *bp;
+ struct xfs_btree_block *block;
+
+ block = xfs_btree_get_block(cur, level, &bp);
+ return __xfs_btree_updkeys(cur, level, block, bp, true);
+}
+
+/*
+ * Update the parent keys of the given level, progressing towards the root.
+ */
+STATIC int
+xfs_btree_update_keys(
+ struct xfs_btree_cur *cur,
+ int level)
+{
+ struct xfs_btree_block *block;
+ struct xfs_buf *bp;
+ union xfs_btree_key *kp;
+ union xfs_btree_key key;
+ int ptr;
+
+ ASSERT(level >= 0);
+
+ block = xfs_btree_get_block(cur, level, &bp);
+ if (cur->bc_flags & XFS_BTREE_OVERLAPPING)
+ return __xfs_btree_updkeys(cur, level, block, bp, false);
+
+ /*
+ * Go up the tree from this level toward the root.
+ * At each level, update the key value to the value input.
+ * Stop when we reach a level where the cursor isn't pointing
+ * at the first entry in the block.
+ */
+ xfs_btree_get_keys(cur, block, &key);
+ for (level++, ptr = 1; ptr == 1 && level < cur->bc_nlevels; level++) {
+#ifdef DEBUG
+ int error;
+#endif
+ block = xfs_btree_get_block(cur, level, &bp);
+#ifdef DEBUG
+ error = xfs_btree_check_block(cur, block, level, bp);
+ if (error)
+ return error;
+#endif
+ ptr = cur->bc_ptrs[level];
+ kp = xfs_btree_key_addr(cur, ptr, block);
+ xfs_btree_copy_keys(cur, kp, &key, 1);
+ xfs_btree_log_keys(cur, bp, ptr, ptr);
+ }
+
+ return 0;
+}
+
+/*
+ * Update the record referred to by cur to the value in the
+ * given record. This either works (return 0) or gets an
+ * EFSCORRUPTED error.
+ */
+int
+xfs_btree_update(
+ struct xfs_btree_cur *cur,
+ union xfs_btree_rec *rec)
+{
+ struct xfs_btree_block *block;
+ struct xfs_buf *bp;
+ int error;
+ int ptr;
+ union xfs_btree_rec *rp;
+
+ /* Pick up the current block. */
+ block = xfs_btree_get_block(cur, 0, &bp);
+
+#ifdef DEBUG
+ error = xfs_btree_check_block(cur, block, 0, bp);
+ if (error)
+ goto error0;
+#endif
+ /* Get the address of the rec to be updated. */
+ ptr = cur->bc_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);
+ }
+
+ /* Pass new key value up to our parent. */
+ if (xfs_btree_needs_key_update(cur, ptr)) {
+ error = xfs_btree_update_keys(cur, 0);
+ if (error)
+ goto error0;
+ }
+
+ return 0;
+
+error0:
+ return error;
+}
+
+/*
+ * Move 1 record left from cur/level if possible.
+ * Update cur to reflect the new path.
+ */
+STATIC int /* error */
+xfs_btree_lshift(
+ struct xfs_btree_cur *cur,
+ int level,
+ int *stat) /* success/failure */
+{
+ struct xfs_buf *lbp; /* left buffer pointer */
+ struct xfs_btree_block *left; /* left btree block */
+ int lrecs; /* left record count */
+ struct xfs_buf *rbp; /* right buffer pointer */
+ struct xfs_btree_block *right; /* right btree block */
+ struct xfs_btree_cur *tcur; /* temporary btree cursor */
+ int rrecs; /* right record count */
+ union xfs_btree_ptr lptr; /* left btree pointer */
+ union xfs_btree_key *rkp = NULL; /* right btree key */
+ union xfs_btree_ptr *rpp = NULL; /* right address pointer */
+ union xfs_btree_rec *rrp = NULL; /* right record pointer */
+ int error; /* error return value */
+ int i;
+
+ if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
+ level == cur->bc_nlevels - 1)
+ goto out0;
+
+ /* Set up variables for this block as "right". */
+ right = xfs_btree_get_block(cur, level, &rbp);
+
+#ifdef DEBUG
+ error = xfs_btree_check_block(cur, right, level, rbp);
+ if (error)
+ goto error0;
+#endif
+
+ /* If we've got no left sibling then we can't shift an entry left. */
+ xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
+ if (xfs_btree_ptr_is_null(cur, &lptr))
+ goto out0;
+
+ /*
+ * If the cursor entry is the one that would be moved, don't
+ * do it... it's too complicated.
+ */
+ if (cur->bc_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);
+
+ error = xfs_btree_debug_check_ptr(cur, rpp, 0, level);
+ if (error)
+ goto error0;
+
+ xfs_btree_copy_keys(cur, lkp, rkp, 1);
+ xfs_btree_copy_ptrs(cur, lpp, rpp, 1);
+
+ xfs_btree_log_keys(cur, lbp, lrecs, lrecs);
+ xfs_btree_log_ptrs(cur, lbp, lrecs, lrecs);
+
+ ASSERT(cur->bc_ops->keys_inorder(cur,
+ xfs_btree_key_addr(cur, lrecs - 1, left), lkp));
+ } else {
+ /* It's a leaf. Move records. */
+ union xfs_btree_rec *lrp; /* left record pointer */
+
+ lrp = xfs_btree_rec_addr(cur, lrecs, left);
+ rrp = xfs_btree_rec_addr(cur, 1, right);
+
+ xfs_btree_copy_recs(cur, lrp, rrp, 1);
+ xfs_btree_log_recs(cur, lbp, lrecs, lrecs);
+
+ ASSERT(cur->bc_ops->recs_inorder(cur,
+ xfs_btree_rec_addr(cur, lrecs - 1, left), lrp));
+ }
+
+ xfs_btree_set_numrecs(left, lrecs);
+ xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS);
+
+ xfs_btree_set_numrecs(right, rrecs);
+ xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS);
+
+ /*
+ * Slide the contents of right down one entry.
+ */
+ XFS_BTREE_STATS_ADD(cur, moves, rrecs - 1);
+ if (level > 0) {
+ /* It's a nonleaf. operate on keys and ptrs */
+ int i; /* loop index */
+
+ for (i = 0; i < rrecs; i++) {
+ error = xfs_btree_debug_check_ptr(cur, rpp, i + 1, level);
+ if (error)
+ goto error0;
+ }
+
+ xfs_btree_shift_keys(cur,
+ xfs_btree_key_addr(cur, 2, right),
+ -1, rrecs);
+ xfs_btree_shift_ptrs(cur,
+ xfs_btree_ptr_addr(cur, 2, right),
+ -1, rrecs);
+
+ xfs_btree_log_keys(cur, rbp, 1, rrecs);
+ xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
+ } else {
+ /* It's a leaf. operate on records */
+ xfs_btree_shift_recs(cur,
+ xfs_btree_rec_addr(cur, 2, right),
+ -1, rrecs);
+ xfs_btree_log_recs(cur, rbp, 1, rrecs);
+ }
+
+ /*
+ * Using a temporary cursor, update the parent key values of the
+ * block on the left.
+ */
+ if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
+ error = xfs_btree_dup_cursor(cur, &tcur);
+ if (error)
+ goto error0;
+ i = xfs_btree_firstrec(tcur, level);
+ XFS_WANT_CORRUPTED_GOTO(tcur->bc_mp, i == 1, error0);
+
+ error = xfs_btree_decrement(tcur, level, &i);
+ if (error)
+ goto error1;
+
+ /* Update the parent high keys of the left block, if needed. */
+ error = xfs_btree_update_keys(tcur, level);
+ if (error)
+ goto error1;
+
+ xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
+ }
+
+ /* Update the parent keys of the right block. */
+ error = xfs_btree_update_keys(cur, level);
+ if (error)
+ goto error0;
+
+ /* Slide the cursor value left one. */
+ cur->bc_ptrs[level]--;
+
+ *stat = 1;
+ return 0;
+
+out0:
+ *stat = 0;
+ return 0;
+
+error0:
+ return error;
+
+error1:
+ xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
+ return error;
+}
+
+/*
+ * Move 1 record right from cur/level if possible.
+ * Update cur to reflect the new path.
+ */
+STATIC int /* error */
+xfs_btree_rshift(
+ struct xfs_btree_cur *cur,
+ int level,
+ int *stat) /* success/failure */
+{
+ struct xfs_buf *lbp; /* left buffer pointer */
+ struct xfs_btree_block *left; /* left btree block */
+ struct xfs_buf *rbp; /* right buffer pointer */
+ struct xfs_btree_block *right; /* right btree block */
+ struct xfs_btree_cur *tcur; /* temporary btree cursor */
+ union xfs_btree_ptr rptr; /* right block pointer */
+ union xfs_btree_key *rkp; /* right btree key */
+ int rrecs; /* right record count */
+ int lrecs; /* left record count */
+ int error; /* error return value */
+ int i; /* loop counter */
+
+ if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
+ (level == cur->bc_nlevels - 1))
+ goto out0;
+
+ /* Set up variables for this block as "left". */
+ left = xfs_btree_get_block(cur, level, &lbp);
+
+#ifdef DEBUG
+ error = xfs_btree_check_block(cur, left, level, lbp);
+ if (error)
+ goto error0;
+#endif
+
+ /* If we've got no right sibling then we can't shift an entry right. */
+ xfs_btree_get_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
+ if (xfs_btree_ptr_is_null(cur, &rptr))
+ goto out0;
+
+ /*
+ * If the cursor entry is the one that would be moved, don't
+ * do it... it's too complicated.
+ */
+ lrecs = xfs_btree_get_numrecs(left);
+ if (cur->bc_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);
+
+ for (i = rrecs - 1; i >= 0; i--) {
+ error = xfs_btree_debug_check_ptr(cur, rpp, i, level);
+ if (error)
+ goto error0;
+ }
+
+ xfs_btree_shift_keys(cur, rkp, 1, rrecs);
+ xfs_btree_shift_ptrs(cur, rpp, 1, rrecs);
+
+ error = xfs_btree_debug_check_ptr(cur, lpp, 0, level);
+ if (error)
+ goto error0;
+
+ /* Now put the new data in, and log it. */
+ xfs_btree_copy_keys(cur, rkp, lkp, 1);
+ xfs_btree_copy_ptrs(cur, rpp, lpp, 1);
+
+ xfs_btree_log_keys(cur, rbp, 1, rrecs + 1);
+ xfs_btree_log_ptrs(cur, rbp, 1, rrecs + 1);
+
+ ASSERT(cur->bc_ops->keys_inorder(cur, rkp,
+ xfs_btree_key_addr(cur, 2, right)));
+ } else {
+ /* It's a leaf. make a hole in the records */
+ union xfs_btree_rec *lrp;
+ union xfs_btree_rec *rrp;
+
+ lrp = xfs_btree_rec_addr(cur, lrecs, left);
+ rrp = xfs_btree_rec_addr(cur, 1, right);
+
+ xfs_btree_shift_recs(cur, rrp, 1, rrecs);
+
+ /* Now put the new data in, and log it. */
+ xfs_btree_copy_recs(cur, rrp, lrp, 1);
+ xfs_btree_log_recs(cur, rbp, 1, rrecs + 1);
+ }
+
+ /*
+ * Decrement and log left's numrecs, bump and log right's numrecs.
+ */
+ xfs_btree_set_numrecs(left, --lrecs);
+ xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS);
+
+ xfs_btree_set_numrecs(right, ++rrecs);
+ xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS);
+
+ /*
+ * Using a temporary cursor, update the parent key values of the
+ * block on the right.
+ */
+ error = xfs_btree_dup_cursor(cur, &tcur);
+ if (error)
+ goto error0;
+ i = xfs_btree_lastrec(tcur, level);
+ XFS_WANT_CORRUPTED_GOTO(tcur->bc_mp, i == 1, error0);
+
+ error = xfs_btree_increment(tcur, level, &i);
+ if (error)
+ goto error1;
+
+ /* Update the parent high keys of the left block, if needed. */
+ if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
+ error = xfs_btree_update_keys(cur, level);
+ if (error)
+ goto error1;
+ }
+
+ /* Update the parent keys of the right block. */
+ error = xfs_btree_update_keys(tcur, level);
+ if (error)
+ goto error1;
+
+ xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
+
+ *stat = 1;
+ return 0;
+
+out0:
+ *stat = 0;
+ return 0;
+
+error0:
+ return error;
+
+error1:
+ xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
+ return error;
+}
+
+/*
+ * Split cur/level block in half.
+ * Return new block number and the key to its first
+ * record (to be inserted into parent).
+ */
+STATIC int /* error */
+__xfs_btree_split(
+ struct xfs_btree_cur *cur,
+ int level,
+ union xfs_btree_ptr *ptrp,
+ union xfs_btree_key *key,
+ struct xfs_btree_cur **curp,
+ int *stat) /* success/failure */
+{
+ union xfs_btree_ptr lptr; /* left sibling block ptr */
+ struct xfs_buf *lbp; /* left buffer pointer */
+ struct xfs_btree_block *left; /* left btree block */
+ union xfs_btree_ptr rptr; /* right sibling block ptr */
+ struct xfs_buf *rbp; /* right buffer pointer */
+ struct xfs_btree_block *right; /* right btree block */
+ union xfs_btree_ptr rrptr; /* right-right sibling ptr */
+ struct xfs_buf *rrbp; /* right-right buffer pointer */
+ struct xfs_btree_block *rrblock; /* right-right btree block */
+ int lrecs;
+ int rrecs;
+ int src_index;
+ int error; /* error return value */
+ int i;
+
+ XFS_BTREE_STATS_INC(cur, split);
+
+ /* Set up left block (current one). */
+ left = xfs_btree_get_block(cur, level, &lbp);
+
+#ifdef DEBUG
+ error = xfs_btree_check_block(cur, left, level, lbp);
+ if (error)
+ goto error0;
+#endif
+
+ xfs_btree_buf_to_ptr(cur, lbp, &lptr);
+
+ /* Allocate the new block. If we can't do it, we're toast. Give up. */
+ error = cur->bc_ops->alloc_block(cur, &lptr, &rptr, stat);
+ if (error)
+ goto error0;
+ if (*stat == 0)
+ goto out0;
+ XFS_BTREE_STATS_INC(cur, alloc);
+
+ /* Set up the new block as "right". */
+ error = xfs_btree_get_buf_block(cur, &rptr, 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);
+
+ /* Adjust numrecs for the later get_*_keys() calls. */
+ lrecs -= rrecs;
+ xfs_btree_set_numrecs(left, lrecs);
+ xfs_btree_set_numrecs(right, xfs_btree_get_numrecs(right) + rrecs);
+
+ /*
+ * Copy btree block entries from the left block over to the
+ * new block, the right. Update the right block and log the
+ * changes.
+ */
+ if (level > 0) {
+ /* It's a non-leaf. Move keys and pointers. */
+ union xfs_btree_key *lkp; /* left btree key */
+ union xfs_btree_ptr *lpp; /* left address pointer */
+ union xfs_btree_key *rkp; /* right btree key */
+ union xfs_btree_ptr *rpp; /* right address pointer */
+
+ lkp = xfs_btree_key_addr(cur, src_index, left);
+ lpp = xfs_btree_ptr_addr(cur, src_index, left);
+ rkp = xfs_btree_key_addr(cur, 1, right);
+ rpp = xfs_btree_ptr_addr(cur, 1, right);
+
+ for (i = src_index; i < rrecs; i++) {
+ error = xfs_btree_debug_check_ptr(cur, lpp, i, level);
+ if (error)
+ goto error0;
+ }
+
+ /* Copy the keys & pointers to the new block. */
+ xfs_btree_copy_keys(cur, rkp, lkp, rrecs);
+ xfs_btree_copy_ptrs(cur, rpp, lpp, rrecs);
+
+ xfs_btree_log_keys(cur, rbp, 1, rrecs);
+ xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
+
+ /* Stash the keys of the new block for later insertion. */
+ xfs_btree_get_node_keys(cur, right, key);
+ } else {
+ /* It's a leaf. Move records. */
+ union xfs_btree_rec *lrp; /* left record pointer */
+ union xfs_btree_rec *rrp; /* right record pointer */
+
+ lrp = xfs_btree_rec_addr(cur, src_index, left);
+ rrp = xfs_btree_rec_addr(cur, 1, right);
+
+ /* Copy records to the new block. */
+ xfs_btree_copy_recs(cur, rrp, lrp, rrecs);
+ xfs_btree_log_recs(cur, rbp, 1, rrecs);
+
+ /* Stash the keys of the new block for later insertion. */
+ xfs_btree_get_leaf_keys(cur, right, key);
+ }
+
+ /*
+ * Find the left block number by looking in the buffer.
+ * Adjust sibling pointers.
+ */
+ xfs_btree_get_sibling(cur, left, &rrptr, XFS_BB_RIGHTSIB);
+ xfs_btree_set_sibling(cur, right, &rrptr, XFS_BB_RIGHTSIB);
+ xfs_btree_set_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
+ xfs_btree_set_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
+
+ xfs_btree_log_block(cur, rbp, XFS_BB_ALL_BITS);
+ xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
+
+ /*
+ * If there's a block to the new block's right, make that block
+ * point back to right instead of to left.
+ */
+ if (!xfs_btree_ptr_is_null(cur, &rrptr)) {
+ error = xfs_btree_read_buf_block(cur, &rrptr,
+ 0, &rrblock, &rrbp);
+ if (error)
+ goto error0;
+ xfs_btree_set_sibling(cur, rrblock, &rptr, XFS_BB_LEFTSIB);
+ xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
+ }
+
+ /* Update the parent high keys of the left block, if needed. */
+ if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
+ error = xfs_btree_update_keys(cur, level);
+ if (error)
+ goto error0;
+ }
+
+ /*
+ * If the cursor is really in the right block, move it there.
+ * If it's just pointing past the last entry in left, then we'll
+ * insert there, so don't change anything in that case.
+ */
+ if (cur->bc_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;
+ *stat = 1;
+ return 0;
+out0:
+ *stat = 0;
+ return 0;
+
+error0:
+ 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_MEMALLOC_NOFS;
+
+ /*
+ * 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 */
+ int i; /* loop counter */
+
+ XFS_BTREE_STATS_INC(cur, newroot);
+
+ ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
+
+ level = cur->bc_nlevels - 1;
+
+ block = xfs_btree_get_iroot(cur);
+ pp = xfs_btree_ptr_addr(cur, 1, block);
+
+ /* Allocate the new block. If we can't do it, we're toast. Give up. */
+ error = cur->bc_ops->alloc_block(cur, pp, &nptr, stat);
+ if (error)
+ goto error0;
+ if (*stat == 0)
+ return 0;
+
+ XFS_BTREE_STATS_INC(cur, alloc);
+
+ /* Copy the root into a real block. */
+ error = xfs_btree_get_buf_block(cur, &nptr, 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);
+ for (i = 0; i < be16_to_cpu(cblock->bb_numrecs); i++) {
+ error = xfs_btree_debug_check_ptr(cur, pp, i, level);
+ if (error)
+ goto error0;
+ }
+
+ xfs_btree_copy_ptrs(cur, cpp, pp, xfs_btree_get_numrecs(cblock));
+
+ error = xfs_btree_debug_check_ptr(cur, &nptr, 0, level);
+ if (error)
+ goto error0;
+
+ xfs_btree_copy_ptrs(cur, pp, &nptr, 1);
+
+ xfs_iroot_realloc(cur->bc_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;
+ return 0;
+error0:
+ return error;
+}
+
+/*
+ * Allocate a new root block, fill it in.
+ */
+STATIC int /* error */
+xfs_btree_new_root(
+ struct xfs_btree_cur *cur, /* btree cursor */
+ int *stat) /* success/failure */
+{
+ struct xfs_btree_block *block; /* one half of the old root block */
+ struct xfs_buf *bp; /* buffer containing block */
+ int error; /* error return value */
+ struct xfs_buf *lbp; /* left buffer pointer */
+ struct xfs_btree_block *left; /* left btree block */
+ struct xfs_buf *nbp; /* new (root) buffer */
+ struct xfs_btree_block *new; /* new (root) btree block */
+ int nptr; /* new value for key index, 1 or 2 */
+ struct xfs_buf *rbp; /* right buffer pointer */
+ struct xfs_btree_block *right; /* right btree block */
+ union xfs_btree_ptr rptr;
+ union xfs_btree_ptr lptr;
+
+ XFS_BTREE_STATS_INC(cur, newroot);
+
+ /* initialise our start point from the cursor */
+ cur->bc_ops->init_ptr_from_cur(cur, &rptr);
+
+ /* Allocate the new block. If we can't do it, we're toast. Give up. */
+ error = cur->bc_ops->alloc_block(cur, &rptr, &lptr, stat);
+ if (error)
+ goto error0;
+ if (*stat == 0)
+ goto out0;
+ XFS_BTREE_STATS_INC(cur, alloc);
+
+ /* Set up the new block. */
+ error = xfs_btree_get_buf_block(cur, &lptr, 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) {
+ /*
+ * Get the keys for the left block's keys and put them directly
+ * in the parent block. Do the same for the right block.
+ */
+ xfs_btree_get_node_keys(cur, left,
+ xfs_btree_key_addr(cur, 1, new));
+ xfs_btree_get_node_keys(cur, right,
+ xfs_btree_key_addr(cur, 2, new));
+ } else {
+ /*
+ * Get the keys for the left block's records and put them
+ * directly in the parent block. Do the same for the right
+ * block.
+ */
+ xfs_btree_get_leaf_keys(cur, left,
+ xfs_btree_key_addr(cur, 1, new));
+ xfs_btree_get_leaf_keys(cur, right,
+ xfs_btree_key_addr(cur, 2, new));
+ }
+ xfs_btree_log_keys(cur, nbp, 1, 2);
+
+ /* Fill in the pointer data in the new root. */
+ xfs_btree_copy_ptrs(cur,
+ xfs_btree_ptr_addr(cur, 1, new), &lptr, 1);
+ xfs_btree_copy_ptrs(cur,
+ xfs_btree_ptr_addr(cur, 2, new), &rptr, 1);
+ xfs_btree_log_ptrs(cur, nbp, 1, 2);
+
+ /* Fix up the cursor. */
+ xfs_btree_setbuf(cur, cur->bc_nlevels, nbp);
+ cur->bc_ptrs[cur->bc_nlevels] = nptr;
+ cur->bc_nlevels++;
+ *stat = 1;
+ return 0;
+error0:
+ return error;
+out0:
+ *stat = 0;
+ return 0;
+}
+
+STATIC int
+xfs_btree_make_block_unfull(
+ struct xfs_btree_cur *cur, /* btree cursor */
+ int level, /* btree level */
+ int numrecs,/* # of recs in block */
+ int *oindex,/* old tree index */
+ int *index, /* new tree index */
+ union xfs_btree_ptr *nptr, /* new btree ptr */
+ struct xfs_btree_cur **ncur, /* new btree cursor */
+ union xfs_btree_key *key, /* key of new block */
+ int *stat)
+{
+ int error = 0;
+
+ if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
+ level == cur->bc_nlevels - 1) {
+ struct xfs_inode *ip = cur->bc_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 */
+ union xfs_btree_key *lkey;
+ int optr; /* old key/record index */
+ int ptr; /* key/record index */
+ int numrecs;/* number of records */
+ int error; /* error return value */
+ int i;
+ xfs_daddr_t old_bn;
+
+ ncur = NULL;
+ lkey = &nkey;
+
+ /*
+ * If we have an external root pointer, and we've made it to the
+ * root level, allocate a new root block and we're done.
+ */
+ if (!(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
+ (level >= cur->bc_nlevels)) {
+ error = xfs_btree_new_root(cur, stat);
+ xfs_btree_set_ptr_null(cur, ptrp);
+
+ return error;
+ }
+
+ /* If we're off the left edge, return failure. */
+ ptr = cur->bc_ptrs[level];
+ if (ptr == 0) {
+ *stat = 0;
+ return 0;
+ }
+
+ optr = ptr;
+
+ XFS_BTREE_STATS_INC(cur, insrec);
+
+ /* Get pointers to the btree buffer and block. */
+ block = xfs_btree_get_block(cur, level, &bp);
+ old_bn = bp ? bp->b_bn : XFS_BUF_DADDR_NULL;
+ numrecs = xfs_btree_get_numrecs(block);
+
+#ifdef DEBUG
+ error = xfs_btree_check_block(cur, block, level, bp);
+ if (error)
+ goto error0;
+
+ /* Check that the new entry is being inserted in the right place. */
+ if (ptr <= numrecs) {
+ if (level == 0) {
+ ASSERT(cur->bc_ops->recs_inorder(cur, rec,
+ xfs_btree_rec_addr(cur, ptr, block)));
+ } else {
+ ASSERT(cur->bc_ops->keys_inorder(cur, key,
+ xfs_btree_key_addr(cur, ptr, block)));
+ }
+ }
+#endif
+
+ /*
+ * If the block is full, we can't insert the new entry until we
+ * make the block un-full.
+ */
+ xfs_btree_set_ptr_null(cur, &nptr);
+ if (numrecs == cur->bc_ops->get_maxrecs(cur, level)) {
+ error = xfs_btree_make_block_unfull(cur, level, numrecs,
+ &optr, &ptr, &nptr, &ncur, lkey, stat);
+ if (error || *stat == 0)
+ goto error0;
+ }
+
+ /*
+ * The current block may have changed if the block was
+ * previously full and we have just made space in it.
+ */
+ block = xfs_btree_get_block(cur, level, &bp);
+ numrecs = xfs_btree_get_numrecs(block);
+
+#ifdef DEBUG
+ error = xfs_btree_check_block(cur, block, level, bp);
+ if (error)
+ 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);
+
+ for (i = numrecs - ptr; i >= 0; i--) {
+ error = xfs_btree_debug_check_ptr(cur, pp, i, level);
+ if (error)
+ return error;
+ }
+
+ xfs_btree_shift_keys(cur, kp, 1, numrecs - ptr + 1);
+ xfs_btree_shift_ptrs(cur, pp, 1, numrecs - ptr + 1);
+
+ error = xfs_btree_debug_check_ptr(cur, ptrp, 0, level);
+ if (error)
+ goto error0;
+
+ /* Now put the new data in, bump numrecs and log it. */
+ xfs_btree_copy_keys(cur, kp, key, 1);
+ xfs_btree_copy_ptrs(cur, pp, ptrp, 1);
+ numrecs++;
+ xfs_btree_set_numrecs(block, numrecs);
+ xfs_btree_log_ptrs(cur, bp, ptr, numrecs);
+ xfs_btree_log_keys(cur, bp, ptr, numrecs);
+#ifdef DEBUG
+ if (ptr < numrecs) {
+ ASSERT(cur->bc_ops->keys_inorder(cur, kp,
+ xfs_btree_key_addr(cur, ptr + 1, block)));
+ }
+#endif
+ } else {
+ /* It's a leaf. make a hole in the records */
+ union xfs_btree_rec *rp;
+
+ rp = xfs_btree_rec_addr(cur, ptr, block);
+
+ xfs_btree_shift_recs(cur, rp, 1, numrecs - ptr + 1);
+
+ /* Now put the new data in, bump numrecs and log it. */
+ xfs_btree_copy_recs(cur, rp, rec, 1);
+ xfs_btree_set_numrecs(block, ++numrecs);
+ xfs_btree_log_recs(cur, bp, ptr, numrecs);
+#ifdef DEBUG
+ if (ptr < numrecs) {
+ ASSERT(cur->bc_ops->recs_inorder(cur, rp,
+ xfs_btree_rec_addr(cur, ptr + 1, block)));
+ }
+#endif
+ }
+
+ /* Log the new number of records in the btree header. */
+ xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
+
+ /*
+ * If we just inserted into a new tree block, we have to
+ * recalculate nkey here because nkey is out of date.
+ *
+ * Otherwise we're just updating an existing block (having shoved
+ * some records into the new tree block), so use the regular key
+ * update mechanism.
+ */
+ if (bp && bp->b_bn != old_bn) {
+ xfs_btree_get_keys(cur, block, lkey);
+ } else if (xfs_btree_needs_key_update(cur, optr)) {
+ error = xfs_btree_update_keys(cur, level);
+ if (error)
+ goto error0;
+ }
+
+ /*
+ * If we are tracking the last record in the tree and
+ * we are at the far right edge of the tree, update it.
+ */
+ if (xfs_btree_is_lastrec(cur, block, level)) {
+ cur->bc_ops->update_lastrec(cur, block, rec,
+ ptr, LASTREC_INSREC);
+ }
+
+ /*
+ * Return the new block number, if any.
+ * If there is one, give back a record value and a cursor too.
+ */
+ *ptrp = nptr;
+ if (!xfs_btree_ptr_is_null(cur, &nptr)) {
+ xfs_btree_copy_keys(cur, key, lkey, 1);
+ *curp = ncur;
+ }
+
+ *stat = 1;
+ return 0;
+
+error0:
+ return error;
+}
+
+/*
+ * Insert the record at the point referenced by cur.
+ *
+ * A multi-level split of the tree on insert will invalidate the original
+ * cursor. All callers of this function should assume that the cursor is
+ * no longer valid and revalidate it.
+ */
+int
+xfs_btree_insert(
+ struct xfs_btree_cur *cur,
+ int *stat)
+{
+ int error; /* error return value */
+ int i; /* result value, 0 for failure */
+ int level; /* current level number in btree */
+ union xfs_btree_ptr nptr; /* new block number (split result) */
+ struct xfs_btree_cur *ncur; /* new cursor (split result) */
+ struct xfs_btree_cur *pcur; /* previous level's cursor */
+ union xfs_btree_key bkey; /* key of block to insert */
+ union xfs_btree_key *key;
+ union xfs_btree_rec rec; /* record to insert */
+
+ level = 0;
+ ncur = NULL;
+ pcur = cur;
+ key = &bkey;
+
+ xfs_btree_set_ptr_null(cur, &nptr);
+
+ /* Make a key out of the record data to be inserted, and save it. */
+ cur->bc_ops->init_rec_from_cur(cur, &rec);
+ cur->bc_ops->init_key_from_rec(key, &rec);
+
+ /*
+ * Loop going up the tree, starting at the leaf level.
+ * Stop when we don't get a split block, that must mean that
+ * the insert is finished with this level.
+ */
+ do {
+ /*
+ * Insert nrec/nptr into this level of the tree.
+ * Note if we fail, nptr will be null.
+ */
+ error = xfs_btree_insrec(pcur, level, &nptr, &rec, key,
+ &ncur, &i);
+ if (error) {
+ if (pcur != cur)
+ xfs_btree_del_cursor(pcur, XFS_BTREE_ERROR);
+ goto error0;
+ }
+
+ 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));
+
+ *stat = i;
+ return 0;
+error0:
+ return error;
+}
+
+/*
+ * Try to merge a non-leaf block back into the inode root.
+ *
+ * Note: the killroot names comes from the fact that we're effectively
+ * killing the old root block. But because we can't just delete the
+ * inode we have to copy the single block it was pointing to into the
+ * inode.
+ */
+STATIC int
+xfs_btree_kill_iroot(
+ struct xfs_btree_cur *cur)
+{
+ int whichfork = cur->bc_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;
+#endif
+ int i;
+
+ ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
+ ASSERT(cur->bc_nlevels > 1);
+
+ /*
+ * Don't deal with the root block needs to be a leaf case.
+ * We're just going to turn the thing back into extents anyway.
+ */
+ level = cur->bc_nlevels - 1;
+ if (level == 1)
+ goto out0;
+
+ /*
+ * Give up if the root has multiple children.
+ */
+ block = xfs_btree_get_iroot(cur);
+ if (xfs_btree_get_numrecs(block) != 1)
+ goto out0;
+
+ cblock = xfs_btree_get_block(cur, level - 1, &cbp);
+ numrecs = xfs_btree_get_numrecs(cblock);
+
+ /*
+ * Only do this if the next level will fit.
+ * Then the data must be copied up to the inode,
+ * instead of freeing the root you free the next level.
+ */
+ if (numrecs > cur->bc_ops->get_dmaxrecs(cur, level))
+ goto out0;
+
+ XFS_BTREE_STATS_INC(cur, killroot);
+
+#ifdef DEBUG
+ xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB);
+ ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
+ xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
+ ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
+#endif
+
+ index = numrecs - cur->bc_ops->get_maxrecs(cur, level);
+ if (index) {
+ xfs_iroot_realloc(cur->bc_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);
+
+ for (i = 0; i < numrecs; i++) {
+ error = xfs_btree_debug_check_ptr(cur, cpp, i, level - 1);
+ if (error)
+ return error;
+ }
+
+ xfs_btree_copy_ptrs(cur, pp, cpp, numrecs);
+
+ error = xfs_btree_free_block(cur, cbp);
+ if (error)
+ return error;
+
+ cur->bc_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:
+ return 0;
+}
+
+/*
+ * Kill the current root node, and replace it with it's only child node.
+ */
+STATIC int
+xfs_btree_kill_root(
+ struct xfs_btree_cur *cur,
+ struct xfs_buf *bp,
+ int level,
+ union xfs_btree_ptr *newroot)
+{
+ int error;
+
+ XFS_BTREE_STATS_INC(cur, killroot);
+
+ /*
+ * Update the root pointer, decreasing the level by 1 and then
+ * free the old root.
+ */
+ cur->bc_ops->set_root(cur, newroot, -1);
+
+ error = xfs_btree_free_block(cur, bp);
+ if (error)
+ return error;
+
+ cur->bc_bufs[level] = NULL;
+ cur->bc_ra[level] = 0;
+ cur->bc_nlevels--;
+
+ return 0;
+}
+
+STATIC int
+xfs_btree_dec_cursor(
+ struct xfs_btree_cur *cur,
+ int level,
+ int *stat)
+{
+ int error;
+ int i;
+
+ if (level > 0) {
+ error = xfs_btree_decrement(cur, level, &i);
+ if (error)
+ return error;
+ }
+
+ *stat = 1;
+ return 0;
+}
+
+/*
+ * Single level of the btree record deletion routine.
+ * Delete record pointed to by cur/level.
+ * Remove the record from its block then rebalance the tree.
+ * Return 0 for error, 1 for done, 2 to go on to the next level.
+ */
+STATIC int /* error */
+xfs_btree_delrec(
+ struct xfs_btree_cur *cur, /* btree cursor */
+ int level, /* level removing record from */
+ int *stat) /* fail/done/go-on */
+{
+ struct xfs_btree_block *block; /* btree block */
+ union xfs_btree_ptr cptr; /* current block ptr */
+ struct xfs_buf *bp; /* buffer for block */
+ int error; /* error return value */
+ int i; /* loop counter */
+ union xfs_btree_ptr lptr; /* left sibling block ptr */
+ struct xfs_buf *lbp; /* left buffer pointer */
+ struct xfs_btree_block *left; /* left btree block */
+ int lrecs = 0; /* left record count */
+ int ptr; /* key/record index */
+ union xfs_btree_ptr rptr; /* right sibling block ptr */
+ struct xfs_buf *rbp; /* right buffer pointer */
+ struct xfs_btree_block *right; /* right btree block */
+ struct xfs_btree_block *rrblock; /* right-right btree block */
+ struct xfs_buf *rrbp; /* right-right buffer pointer */
+ int rrecs = 0; /* right record count */
+ struct xfs_btree_cur *tcur; /* temporary btree cursor */
+ int numrecs; /* temporary numrec count */
+
+ tcur = NULL;
+
+ /* Get the index of the entry being deleted, check for nothing there. */
+ ptr = cur->bc_ptrs[level];
+ if (ptr == 0) {
+ *stat = 0;
+ return 0;
+ }
+
+ /* Get the buffer & block containing the record or key/ptr. */
+ block = xfs_btree_get_block(cur, level, &bp);
+ numrecs = xfs_btree_get_numrecs(block);
+
+#ifdef DEBUG
+ error = xfs_btree_check_block(cur, block, level, bp);
+ if (error)
+ goto error0;
+#endif
+
+ /* Fail if we're off the end of the block. */
+ if (ptr > numrecs) {
+ *stat = 0;
+ return 0;
+ }
+
+ XFS_BTREE_STATS_INC(cur, delrec);
+ XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr);
+
+ /* Excise the entries being deleted. */
+ if (level > 0) {
+ /* It's a nonleaf. operate on keys and ptrs */
+ union xfs_btree_key *lkp;
+ union xfs_btree_ptr *lpp;
+
+ lkp = xfs_btree_key_addr(cur, ptr + 1, block);
+ lpp = xfs_btree_ptr_addr(cur, ptr + 1, block);
+
+ for (i = 0; i < numrecs - ptr; i++) {
+ error = xfs_btree_debug_check_ptr(cur, lpp, i, level);
+ if (error)
+ goto error0;
+ }
+
+ if (ptr < numrecs) {
+ xfs_btree_shift_keys(cur, lkp, -1, numrecs - ptr);
+ xfs_btree_shift_ptrs(cur, lpp, -1, numrecs - ptr);
+ xfs_btree_log_keys(cur, bp, ptr, numrecs - 1);
+ xfs_btree_log_ptrs(cur, bp, ptr, numrecs - 1);
+ }
+ } else {
+ /* It's a leaf. operate on records */
+ if (ptr < numrecs) {
+ xfs_btree_shift_recs(cur,
+ xfs_btree_rec_addr(cur, ptr + 1, block),
+ -1, numrecs - ptr);
+ xfs_btree_log_recs(cur, bp, ptr, numrecs - 1);
+ }
+ }
+
+ /*
+ * Decrement and log the number of entries in the block.
+ */
+ xfs_btree_set_numrecs(block, --numrecs);
+ xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
+
+ /*
+ * If we are tracking the last record in the tree and
+ * we are at the far right edge of the tree, update it.
+ */
+ if (xfs_btree_is_lastrec(cur, block, level)) {
+ cur->bc_ops->update_lastrec(cur, block, NULL,
+ ptr, LASTREC_DELREC);
+ }
+
+ /*
+ * We're at the root level. First, shrink the root block in-memory.
+ * Try to get rid of the next level down. If we can't then there's
+ * nothing left to do.
+ */
+ if (level == cur->bc_nlevels - 1) {
+ if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) {
+ xfs_iroot_realloc(cur->bc_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 (xfs_btree_needs_key_update(cur, ptr)) {
+ error = xfs_btree_update_keys(cur, level);
+ if (error)
+ goto error0;
+ }
+
+ /*
+ * If the number of records remaining in the block is at least
+ * the minimum, we're done.
+ */
+ if (numrecs >= cur->bc_ops->get_minrecs(cur, level)) {
+ error = xfs_btree_dec_cursor(cur, level, stat);
+ if (error)
+ goto error0;
+ return 0;
+ }
+
+ /*
+ * Otherwise, we have to move some records around to keep the
+ * tree balanced. Look at the left and right sibling blocks to
+ * see if we can re-balance by moving only one record.
+ */
+ xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
+ xfs_btree_get_sibling(cur, block, &lptr, XFS_BB_LEFTSIB);
+
+ if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) {
+ /*
+ * One child of root, need to get a chance to copy its contents
+ * into the root and delete it. Can't go up to next level,
+ * there's nothing to delete there.
+ */
+ if (xfs_btree_ptr_is_null(cur, &rptr) &&
+ xfs_btree_ptr_is_null(cur, &lptr) &&
+ level == cur->bc_nlevels - 2) {
+ error = xfs_btree_kill_iroot(cur);
+ if (!error)
+ error = xfs_btree_dec_cursor(cur, level, stat);
+ if (error)
+ goto error0;
+ return 0;
+ }
+ }
+
+ ASSERT(!xfs_btree_ptr_is_null(cur, &rptr) ||
+ !xfs_btree_ptr_is_null(cur, &lptr));
+
+ /*
+ * Duplicate the cursor so our btree manipulations here won't
+ * disrupt the next level up.
+ */
+ error = xfs_btree_dup_cursor(cur, &tcur);
+ if (error)
+ goto error0;
+
+ /*
+ * If there's a right sibling, see if it's ok to shift an entry
+ * out of it.
+ */
+ if (!xfs_btree_ptr_is_null(cur, &rptr)) {
+ /*
+ * Move the temp cursor to the last entry in the next block.
+ * Actually any entry but the first would suffice.
+ */
+ i = xfs_btree_lastrec(tcur, level);
+ 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]++;
+
+ *stat = 1;
+ return 0;
+ }
+ }
+
+ /*
+ * Otherwise, grab the number of records in right for
+ * future reference.
+ */
+ lrecs = xfs_btree_get_numrecs(left);
+ }
+
+ /* Delete the temp cursor, we're done with it. */
+ xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
+ tcur = NULL;
+
+ /* If here, we need to do a join to keep the tree balanced. */
+ ASSERT(!xfs_btree_ptr_is_null(cur, &cptr));
+
+ if (!xfs_btree_ptr_is_null(cur, &lptr) &&
+ lrecs + xfs_btree_get_numrecs(block) <=
+ cur->bc_ops->get_maxrecs(cur, level)) {
+ /*
+ * Set "right" to be the starting block,
+ * "left" to be the left neighbor.
+ */
+ rptr = cptr;
+ right = block;
+ rbp = bp;
+ error = xfs_btree_read_buf_block(cur, &lptr, 0, &left, &lbp);
+ if (error)
+ goto error0;
+
+ /*
+ * If that won't work, see if we can join with the right neighbor block.
+ */
+ } else if (!xfs_btree_ptr_is_null(cur, &rptr) &&
+ rrecs + xfs_btree_get_numrecs(block) <=
+ cur->bc_ops->get_maxrecs(cur, level)) {
+ /*
+ * Set "left" to be the starting block,
+ * "right" to be the right neighbor.
+ */
+ lptr = cptr;
+ left = block;
+ lbp = bp;
+ error = xfs_btree_read_buf_block(cur, &rptr, 0, &right, &rbp);
+ if (error)
+ goto error0;
+
+ /*
+ * Otherwise, we can't fix the imbalance.
+ * Just return. This is probably a logic error, but it's not fatal.
+ */
+ } else {
+ error = xfs_btree_dec_cursor(cur, level, stat);
+ if (error)
+ goto error0;
+ return 0;
+ }
+
+ rrecs = xfs_btree_get_numrecs(right);
+ lrecs = xfs_btree_get_numrecs(left);
+
+ /*
+ * We're now going to join "left" and "right" by moving all the stuff
+ * in "right" to "left" and deleting "right".
+ */
+ XFS_BTREE_STATS_ADD(cur, moves, rrecs);
+ if (level > 0) {
+ /* It's a non-leaf. Move keys and pointers. */
+ union xfs_btree_key *lkp; /* left btree key */
+ union xfs_btree_ptr *lpp; /* left address pointer */
+ union xfs_btree_key *rkp; /* right btree key */
+ union xfs_btree_ptr *rpp; /* right address pointer */
+
+ lkp = xfs_btree_key_addr(cur, lrecs + 1, left);
+ lpp = xfs_btree_ptr_addr(cur, lrecs + 1, left);
+ rkp = xfs_btree_key_addr(cur, 1, right);
+ rpp = xfs_btree_ptr_addr(cur, 1, right);
+
+ for (i = 1; i < rrecs; i++) {
+ error = xfs_btree_debug_check_ptr(cur, rpp, i, level);
+ if (error)
+ goto error0;
+ }
+
+ xfs_btree_copy_keys(cur, lkp, rkp, rrecs);
+ xfs_btree_copy_ptrs(cur, lpp, rpp, rrecs);
+
+ xfs_btree_log_keys(cur, lbp, lrecs + 1, lrecs + rrecs);
+ xfs_btree_log_ptrs(cur, lbp, lrecs + 1, lrecs + rrecs);
+ } else {
+ /* It's a leaf. Move records. */
+ union xfs_btree_rec *lrp; /* left record pointer */
+ union xfs_btree_rec *rrp; /* right record pointer */
+
+ lrp = xfs_btree_rec_addr(cur, lrecs + 1, left);
+ rrp = xfs_btree_rec_addr(cur, 1, right);
+
+ xfs_btree_copy_recs(cur, lrp, rrp, rrecs);
+ xfs_btree_log_recs(cur, lbp, lrecs + 1, lrecs + rrecs);
+ }
+
+ XFS_BTREE_STATS_INC(cur, join);
+
+ /*
+ * Fix up the number of records and right block pointer in the
+ * surviving block, and log it.
+ */
+ xfs_btree_set_numrecs(left, lrecs + rrecs);
+ xfs_btree_get_sibling(cur, right, &cptr, XFS_BB_RIGHTSIB),
+ xfs_btree_set_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
+ xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
+
+ /* If there is a right sibling, point it to the remaining block. */
+ xfs_btree_get_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
+ if (!xfs_btree_ptr_is_null(cur, &cptr)) {
+ error = xfs_btree_read_buf_block(cur, &cptr, 0, &rrblock, &rrbp);
+ if (error)
+ goto error0;
+ xfs_btree_set_sibling(cur, rrblock, &lptr, XFS_BB_LEFTSIB);
+ xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
+ }
+
+ /* Free the deleted block. */
+ error = xfs_btree_free_block(cur, rbp);
+ if (error)
+ goto error0;
+
+ /*
+ * If we joined with the left neighbor, set the buffer in the
+ * cursor to the left block, and fix up the index.
+ */
+ if (bp != lbp) {
+ cur->bc_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]--;
+
+ /*
+ * We combined blocks, so we have to update the parent keys if the
+ * btree supports overlapped intervals. However, bc_ptrs[level + 1]
+ * points to the old block so that the caller knows which record to
+ * delete. Therefore, the caller must be savvy enough to call updkeys
+ * for us if we return stat == 2. The other exit points from this
+ * function don't require deletions further up the tree, so they can
+ * call updkeys directly.
+ */
+
+ /* Return value means the next level up has something to do. */
+ *stat = 2;
+ return 0;
+
+error0:
+ if (tcur)
+ xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
+ return error;
+}
+
+/*
+ * Delete the record pointed to by cur.
+ * The cursor refers to the place where the record was (could be inserted)
+ * when the operation returns.
+ */
+int /* error */
+xfs_btree_delete(
+ struct xfs_btree_cur *cur,
+ int *stat) /* success/failure */
+{
+ int error; /* error return value */
+ int level;
+ int i;
+ bool joined = false;
+
+ /*
+ * Go up the tree, starting at leaf level.
+ *
+ * If 2 is returned then a join was done; go to the next level.
+ * Otherwise we are done.
+ */
+ for (level = 0, i = 2; i == 2; level++) {
+ error = xfs_btree_delrec(cur, level, &i);
+ if (error)
+ goto error0;
+ if (i == 2)
+ joined = true;
+ }
+
+ /*
+ * If we combined blocks as part of deleting the record, delrec won't
+ * have updated the parent high keys so we have to do that here.
+ */
+ if (joined && (cur->bc_flags & XFS_BTREE_OVERLAPPING)) {
+ error = xfs_btree_updkeys_force(cur, 0);
+ if (error)
+ goto error0;
+ }
+
+ if (i == 0) {
+ for (level = 1; level < cur->bc_nlevels; level++) {
+ if (cur->bc_ptrs[level] == 0) {
+ error = xfs_btree_decrement(cur, level, &i);
+ if (error)
+ goto error0;
+ break;
+ }
+ }
+ }
+
+ *stat = i;
+ return 0;
+error0:
+ return error;
+}
+
+/*
+ * Get the data from the pointed-to record.
+ */
+int /* error */
+xfs_btree_get_rec(
+ struct xfs_btree_cur *cur, /* btree cursor */
+ union xfs_btree_rec **recp, /* output: btree record */
+ int *stat) /* output: success/failure */
+{
+ struct xfs_btree_block *block; /* btree block */
+ struct xfs_buf *bp; /* buffer pointer */
+ int ptr; /* record number */
+#ifdef DEBUG
+ int error; /* error return value */
+#endif
+
+ ptr = cur->bc_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;
+}
+
+/* Visit a block in a btree. */
+STATIC int
+xfs_btree_visit_block(
+ struct xfs_btree_cur *cur,
+ int level,
+ xfs_btree_visit_blocks_fn fn,
+ void *data)
+{
+ struct xfs_btree_block *block;
+ struct xfs_buf *bp;
+ union xfs_btree_ptr rptr;
+ int error;
+
+ /* do right sibling readahead */
+ xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA);
+ block = xfs_btree_get_block(cur, level, &bp);
+
+ /* process the block */
+ error = fn(cur, level, data);
+ if (error)
+ return error;
+
+ /* now read rh sibling block for next iteration */
+ xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
+ if (xfs_btree_ptr_is_null(cur, &rptr))
+ return -ENOENT;
+
+ return xfs_btree_lookup_get_block(cur, level, &rptr, &block);
+}
+
+
+/* Visit every block in a btree. */
+int
+xfs_btree_visit_blocks(
+ struct xfs_btree_cur *cur,
+ xfs_btree_visit_blocks_fn fn,
+ void *data)
+{
+ union xfs_btree_ptr lptr;
+ int level;
+ struct xfs_btree_block *block = NULL;
+ int error = 0;
+
+ cur->bc_ops->init_ptr_from_cur(cur, &lptr);
+
+ /* for each level */
+ for (level = cur->bc_nlevels - 1; level >= 0; level--) {
+ /* grab the left hand block */
+ error = xfs_btree_lookup_get_block(cur, level, &lptr, &block);
+ if (error)
+ return error;
+
+ /* readahead the left most block for the next level down */
+ if (level > 0) {
+ union xfs_btree_ptr *ptr;
+
+ ptr = xfs_btree_ptr_addr(cur, 1, block);
+ xfs_btree_readahead_ptr(cur, ptr, 1);
+
+ /* save for the next iteration of the loop */
+ xfs_btree_copy_ptrs(cur, &lptr, ptr, 1);
+ }
+
+ /* for each buffer in the level */
+ do {
+ error = xfs_btree_visit_block(cur, level, fn, data);
+ } while (!error);
+
+ if (error != -ENOENT)
+ return error;
+ }
+
+ return 0;
+}
+
+/*
+ * Change the owner of a btree.
+ *
+ * The mechanism we use here is ordered buffer logging. Because we don't know
+ * how many buffers were are going to need to modify, we don't really want to
+ * have to make transaction reservations for the worst case of every buffer in a
+ * full size btree as that may be more space that we can fit in the log....
+ *
+ * We do the btree walk in the most optimal manner possible - we have sibling
+ * pointers so we can just walk all the blocks on each level from left to right
+ * in a single pass, and then move to the next level and do the same. We can
+ * also do readahead on the sibling pointers to get IO moving more quickly,
+ * though for slow disks this is unlikely to make much difference to performance
+ * as the amount of CPU work we have to do before moving to the next block is
+ * relatively small.
+ *
+ * For each btree block that we load, modify the owner appropriately, set the
+ * buffer as an ordered buffer and log it appropriately. We need to ensure that
+ * we mark the region we change dirty so that if the buffer is relogged in
+ * a subsequent transaction the changes we make here as an ordered buffer are
+ * correctly relogged in that transaction. If we are in recovery context, then
+ * just queue the modified buffer as delayed write buffer so the transaction
+ * recovery completion writes the changes to disk.
+ */
+struct xfs_btree_block_change_owner_info {
+ uint64_t new_owner;
+ struct list_head *buffer_list;
+};
+
+static int
+xfs_btree_block_change_owner(
+ struct xfs_btree_cur *cur,
+ int level,
+ void *data)
+{
+ struct xfs_btree_block_change_owner_info *bbcoi = data;
+ struct xfs_btree_block *block;
+ struct xfs_buf *bp;
+
+ /* modify the owner */
+ block = xfs_btree_get_block(cur, level, &bp);
+ if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
+ if (block->bb_u.l.bb_owner == cpu_to_be64(bbcoi->new_owner))
+ return 0;
+ block->bb_u.l.bb_owner = cpu_to_be64(bbcoi->new_owner);
+ } else {
+ if (block->bb_u.s.bb_owner == cpu_to_be32(bbcoi->new_owner))
+ return 0;
+ block->bb_u.s.bb_owner = cpu_to_be32(bbcoi->new_owner);
+ }
+
+ /*
+ * If the block is a root block hosted in an inode, we might not have a
+ * buffer pointer here and we shouldn't attempt to log the change as the
+ * information is already held in the inode and discarded when the root
+ * block is formatted into the on-disk inode fork. We still change it,
+ * though, so everything is consistent in memory.
+ */
+ if (!bp) {
+ ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
+ ASSERT(level == cur->bc_nlevels - 1);
+ return 0;
+ }
+
+ if (cur->bc_tp) {
+ if (!xfs_trans_ordered_buf(cur->bc_tp, bp)) {
+ xfs_btree_log_block(cur, bp, XFS_BB_OWNER);
+ return -EAGAIN;
+ }
+ } else {
+ xfs_buf_delwri_queue(bp, bbcoi->buffer_list);
+ }
+
+ return 0;
+}
+
+int
+xfs_btree_change_owner(
+ struct xfs_btree_cur *cur,
+ uint64_t new_owner,
+ struct list_head *buffer_list)
+{
+ struct xfs_btree_block_change_owner_info bbcoi;
+
+ bbcoi.new_owner = new_owner;
+ bbcoi.buffer_list = buffer_list;
+
+ return xfs_btree_visit_blocks(cur, xfs_btree_block_change_owner,
+ &bbcoi);
+}
+
+/* Verify the v5 fields of a long-format btree block. */
+xfs_failaddr_t
+xfs_btree_lblock_v5hdr_verify(
+ struct xfs_buf *bp,
+ uint64_t owner)
+{
+ struct xfs_mount *mp = bp->b_target->bt_mount;
+ struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
+
+ if (!xfs_sb_version_hascrc(&mp->m_sb))
+ return __this_address;
+ if (!uuid_equal(&block->bb_u.l.bb_uuid, &mp->m_sb.sb_meta_uuid))
+ return __this_address;
+ if (block->bb_u.l.bb_blkno != cpu_to_be64(bp->b_bn))
+ return __this_address;
+ if (owner != XFS_RMAP_OWN_UNKNOWN &&
+ be64_to_cpu(block->bb_u.l.bb_owner) != owner)
+ return __this_address;
+ return NULL;
+}
+
+/* Verify a long-format btree block. */
+xfs_failaddr_t
+xfs_btree_lblock_verify(
+ struct xfs_buf *bp,
+ unsigned int max_recs)
+{
+ struct xfs_mount *mp = bp->b_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 __this_address;
+
+ /* sibling pointer verification */
+ if (block->bb_u.l.bb_leftsib != cpu_to_be64(NULLFSBLOCK) &&
+ !xfs_verify_fsbno(mp, be64_to_cpu(block->bb_u.l.bb_leftsib)))
+ return __this_address;
+ if (block->bb_u.l.bb_rightsib != cpu_to_be64(NULLFSBLOCK) &&
+ !xfs_verify_fsbno(mp, be64_to_cpu(block->bb_u.l.bb_rightsib)))
+ return __this_address;
+
+ return NULL;
+}
+
+/**
+ * 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
+ */
+xfs_failaddr_t
+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 __this_address;
+ if (!uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid))
+ return __this_address;
+ if (block->bb_u.s.bb_blkno != cpu_to_be64(bp->b_bn))
+ return __this_address;
+ if (pag && be32_to_cpu(block->bb_u.s.bb_owner) != pag->pag_agno)
+ return __this_address;
+ return NULL;
+}
+
+/**
+ * xfs_btree_sblock_verify() -- verify a short-format btree block
+ *
+ * @bp: buffer containing the btree block
+ * @max_recs: maximum records allowed in this btree node
+ */
+xfs_failaddr_t
+xfs_btree_sblock_verify(
+ struct xfs_buf *bp,
+ unsigned int max_recs)
+{
+ struct xfs_mount *mp = bp->b_target->bt_mount;
+ struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
+ xfs_agblock_t agno;
+
+ /* numrecs verification */
+ if (be16_to_cpu(block->bb_numrecs) > max_recs)
+ return __this_address;
+
+ /* sibling pointer verification */
+ agno = xfs_daddr_to_agno(mp, XFS_BUF_ADDR(bp));
+ if (block->bb_u.s.bb_leftsib != cpu_to_be32(NULLAGBLOCK) &&
+ !xfs_verify_agbno(mp, agno, be32_to_cpu(block->bb_u.s.bb_leftsib)))
+ return __this_address;
+ if (block->bb_u.s.bb_rightsib != cpu_to_be32(NULLAGBLOCK) &&
+ !xfs_verify_agbno(mp, agno, be32_to_cpu(block->bb_u.s.bb_rightsib)))
+ return __this_address;
+
+ return NULL;
+}
+
+/*
+ * Calculate the number of btree levels needed to store a given number of
+ * records in a short-format btree.
+ */
+uint
+xfs_btree_compute_maxlevels(
+ 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;
+}
+
+/*
+ * Query a regular btree for all records overlapping a given interval.
+ * Start with a LE lookup of the key of low_rec and return all records
+ * until we find a record with a key greater than the key of high_rec.
+ */
+STATIC int
+xfs_btree_simple_query_range(
+ struct xfs_btree_cur *cur,
+ union xfs_btree_key *low_key,
+ union xfs_btree_key *high_key,
+ xfs_btree_query_range_fn fn,
+ void *priv)
+{
+ union xfs_btree_rec *recp;
+ union xfs_btree_key rec_key;
+ int64_t diff;
+ int stat;
+ bool firstrec = true;
+ int error;
+
+ ASSERT(cur->bc_ops->init_high_key_from_rec);
+ ASSERT(cur->bc_ops->diff_two_keys);
+
+ /*
+ * Find the leftmost record. The btree cursor must be set
+ * to the low record used to generate low_key.
+ */
+ stat = 0;
+ error = xfs_btree_lookup(cur, XFS_LOOKUP_LE, &stat);
+ if (error)
+ goto out;
+
+ /* Nothing? See if there's anything to the right. */
+ if (!stat) {
+ error = xfs_btree_increment(cur, 0, &stat);
+ if (error)
+ goto out;
+ }
+
+ while (stat) {
+ /* Find the record. */
+ error = xfs_btree_get_rec(cur, &recp, &stat);
+ if (error || !stat)
+ break;
+
+ /* Skip if high_key(rec) < low_key. */
+ if (firstrec) {
+ cur->bc_ops->init_high_key_from_rec(&rec_key, recp);
+ firstrec = false;
+ diff = cur->bc_ops->diff_two_keys(cur, low_key,
+ &rec_key);
+ if (diff > 0)
+ goto advloop;
+ }
+
+ /* Stop if high_key < low_key(rec). */
+ cur->bc_ops->init_key_from_rec(&rec_key, recp);
+ diff = cur->bc_ops->diff_two_keys(cur, &rec_key, high_key);
+ if (diff > 0)
+ break;
+
+ /* Callback */
+ error = fn(cur, recp, priv);
+ if (error < 0 || error == XFS_BTREE_QUERY_RANGE_ABORT)
+ break;
+
+advloop:
+ /* Move on to the next record. */
+ error = xfs_btree_increment(cur, 0, &stat);
+ if (error)
+ break;
+ }
+
+out:
+ return error;
+}
+
+/*
+ * Query an overlapped interval btree for all records overlapping a given
+ * interval. This function roughly follows the algorithm given in
+ * "Interval Trees" of _Introduction to Algorithms_, which is section
+ * 14.3 in the 2nd and 3rd editions.
+ *
+ * First, generate keys for the low and high records passed in.
+ *
+ * For any leaf node, generate the high and low keys for the record.
+ * If the record keys overlap with the query low/high keys, pass the
+ * record to the function iterator.
+ *
+ * For any internal node, compare the low and high keys of each
+ * pointer against the query low/high keys. If there's an overlap,
+ * follow the pointer.
+ *
+ * As an optimization, we stop scanning a block when we find a low key
+ * that is greater than the query's high key.
+ */
+STATIC int
+xfs_btree_overlapped_query_range(
+ struct xfs_btree_cur *cur,
+ union xfs_btree_key *low_key,
+ union xfs_btree_key *high_key,
+ xfs_btree_query_range_fn fn,
+ void *priv)
+{
+ union xfs_btree_ptr ptr;
+ union xfs_btree_ptr *pp;
+ union xfs_btree_key rec_key;
+ union xfs_btree_key rec_hkey;
+ union xfs_btree_key *lkp;
+ union xfs_btree_key *hkp;
+ union xfs_btree_rec *recp;
+ struct xfs_btree_block *block;
+ int64_t ldiff;
+ int64_t hdiff;
+ int level;
+ struct xfs_buf *bp;
+ int i;
+ int error;
+
+ /* Load the root of the btree. */
+ level = cur->bc_nlevels - 1;
+ cur->bc_ops->init_ptr_from_cur(cur, &ptr);
+ error = xfs_btree_lookup_get_block(cur, level, &ptr, &block);
+ if (error)
+ return error;
+ xfs_btree_get_block(cur, level, &bp);
+ trace_xfs_btree_overlapped_query_range(cur, level, bp);
+#ifdef DEBUG
+ error = xfs_btree_check_block(cur, block, level, bp);
+ if (error)
+ goto out;
+#endif
+ cur->bc_ptrs[level] = 1;
+
+ while (level < cur->bc_nlevels) {
+ block = xfs_btree_get_block(cur, level, &bp);
+
+ /* End of node, pop back towards the root. */
+ if (cur->bc_ptrs[level] > be16_to_cpu(block->bb_numrecs)) {
+pop_up:
+ if (level < cur->bc_nlevels - 1)
+ cur->bc_ptrs[level + 1]++;
+ level++;
+ continue;
+ }
+
+ if (level == 0) {
+ /* Handle a leaf node. */
+ recp = xfs_btree_rec_addr(cur, cur->bc_ptrs[0], block);
+
+ cur->bc_ops->init_high_key_from_rec(&rec_hkey, recp);
+ ldiff = cur->bc_ops->diff_two_keys(cur, &rec_hkey,
+ low_key);
+
+ cur->bc_ops->init_key_from_rec(&rec_key, recp);
+ hdiff = cur->bc_ops->diff_two_keys(cur, high_key,
+ &rec_key);
+
+ /*
+ * If (record's high key >= query's low key) and
+ * (query's high key >= record's low key), then
+ * this record overlaps the query range; callback.
+ */
+ if (ldiff >= 0 && hdiff >= 0) {
+ error = fn(cur, recp, priv);
+ if (error < 0 ||
+ error == XFS_BTREE_QUERY_RANGE_ABORT)
+ break;
+ } else if (hdiff < 0) {
+ /* Record is larger than high key; pop. */
+ goto pop_up;
+ }
+ cur->bc_ptrs[level]++;
+ continue;
+ }
+
+ /* Handle an internal node. */
+ lkp = xfs_btree_key_addr(cur, cur->bc_ptrs[level], block);
+ hkp = xfs_btree_high_key_addr(cur, cur->bc_ptrs[level], block);
+ pp = xfs_btree_ptr_addr(cur, cur->bc_ptrs[level], block);
+
+ ldiff = cur->bc_ops->diff_two_keys(cur, hkp, low_key);
+ hdiff = cur->bc_ops->diff_two_keys(cur, high_key, lkp);
+
+ /*
+ * If (pointer's high key >= query's low key) and
+ * (query's high key >= pointer's low key), then
+ * this record overlaps the query range; follow pointer.
+ */
+ if (ldiff >= 0 && hdiff >= 0) {
+ level--;
+ error = xfs_btree_lookup_get_block(cur, level, pp,
+ &block);
+ if (error)
+ goto out;
+ xfs_btree_get_block(cur, level, &bp);
+ trace_xfs_btree_overlapped_query_range(cur, level, bp);
+#ifdef DEBUG
+ error = xfs_btree_check_block(cur, block, level, bp);
+ if (error)
+ goto out;
+#endif
+ cur->bc_ptrs[level] = 1;
+ continue;
+ } else if (hdiff < 0) {
+ /* The low key is larger than the upper range; pop. */
+ goto pop_up;
+ }
+ cur->bc_ptrs[level]++;
+ }
+
+out:
+ /*
+ * If we don't end this function with the cursor pointing at a record
+ * block, a subsequent non-error cursor deletion will not release
+ * node-level buffers, causing a buffer leak. This is quite possible
+ * with a zero-results range query, so release the buffers if we
+ * failed to return any results.
+ */
+ if (cur->bc_bufs[0] == NULL) {
+ for (i = 0; i < cur->bc_nlevels; i++) {
+ if (cur->bc_bufs[i]) {
+ xfs_trans_brelse(cur->bc_tp, cur->bc_bufs[i]);
+ cur->bc_bufs[i] = NULL;
+ cur->bc_ptrs[i] = 0;
+ cur->bc_ra[i] = 0;
+ }
+ }
+ }
+
+ return error;
+}
+
+/*
+ * Query a btree for all records overlapping a given interval of keys. The
+ * supplied function will be called with each record found; return one of the
+ * XFS_BTREE_QUERY_RANGE_{CONTINUE,ABORT} values or the usual negative error
+ * code. This function returns XFS_BTREE_QUERY_RANGE_ABORT, zero, or a
+ * negative error code.
+ */
+int
+xfs_btree_query_range(
+ struct xfs_btree_cur *cur,
+ union xfs_btree_irec *low_rec,
+ union xfs_btree_irec *high_rec,
+ xfs_btree_query_range_fn fn,
+ void *priv)
+{
+ union xfs_btree_rec rec;
+ union xfs_btree_key low_key;
+ union xfs_btree_key high_key;
+
+ /* Find the keys of both ends of the interval. */
+ cur->bc_rec = *high_rec;
+ cur->bc_ops->init_rec_from_cur(cur, &rec);
+ cur->bc_ops->init_key_from_rec(&high_key, &rec);
+
+ cur->bc_rec = *low_rec;
+ cur->bc_ops->init_rec_from_cur(cur, &rec);
+ cur->bc_ops->init_key_from_rec(&low_key, &rec);
+
+ /* Enforce low key < high key. */
+ if (cur->bc_ops->diff_two_keys(cur, &low_key, &high_key) > 0)
+ return -EINVAL;
+
+ if (!(cur->bc_flags & XFS_BTREE_OVERLAPPING))
+ return xfs_btree_simple_query_range(cur, &low_key,
+ &high_key, fn, priv);
+ return xfs_btree_overlapped_query_range(cur, &low_key, &high_key,
+ fn, priv);
+}
+
+/* Query a btree for all records. */
+int
+xfs_btree_query_all(
+ struct xfs_btree_cur *cur,
+ xfs_btree_query_range_fn fn,
+ void *priv)
+{
+ union xfs_btree_key low_key;
+ union xfs_btree_key high_key;
+
+ memset(&cur->bc_rec, 0, sizeof(cur->bc_rec));
+ memset(&low_key, 0, sizeof(low_key));
+ memset(&high_key, 0xFF, sizeof(high_key));
+
+ return xfs_btree_simple_query_range(cur, &low_key, &high_key, fn, priv);
+}
+
+/*
+ * Calculate the number of blocks needed to store a given number of records
+ * in a short-format (per-AG metadata) btree.
+ */
+unsigned long long
+xfs_btree_calc_size(
+ uint *limits,
+ unsigned long long len)
+{
+ int level;
+ int maxrecs;
+ unsigned long long rval;
+
+ maxrecs = limits[0];
+ for (level = 0, rval = 0; len > 1; level++) {
+ len += maxrecs - 1;
+ do_div(len, maxrecs);
+ maxrecs = limits[1];
+ rval += len;
+ }
+ return rval;
+}
+
+static int
+xfs_btree_count_blocks_helper(
+ struct xfs_btree_cur *cur,
+ int level,
+ void *data)
+{
+ xfs_extlen_t *blocks = data;
+ (*blocks)++;
+
+ return 0;
+}
+
+/* Count the blocks in a btree and return the result in *blocks. */
+int
+xfs_btree_count_blocks(
+ struct xfs_btree_cur *cur,
+ xfs_extlen_t *blocks)
+{
+ *blocks = 0;
+ return xfs_btree_visit_blocks(cur, xfs_btree_count_blocks_helper,
+ blocks);
+}
+
+/* Compare two btree pointers. */
+int64_t
+xfs_btree_diff_two_ptrs(
+ struct xfs_btree_cur *cur,
+ const union xfs_btree_ptr *a,
+ const union xfs_btree_ptr *b)
+{
+ if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
+ return (int64_t)be64_to_cpu(a->l) - be64_to_cpu(b->l);
+ return (int64_t)be32_to_cpu(a->s) - be32_to_cpu(b->s);
+}
+
+/* If there's an extent, we're done. */
+STATIC int
+xfs_btree_has_record_helper(
+ struct xfs_btree_cur *cur,
+ union xfs_btree_rec *rec,
+ void *priv)
+{
+ return XFS_BTREE_QUERY_RANGE_ABORT;
+}
+
+/* Is there a record covering a given range of keys? */
+int
+xfs_btree_has_record(
+ struct xfs_btree_cur *cur,
+ union xfs_btree_irec *low,
+ union xfs_btree_irec *high,
+ bool *exists)
+{
+ int error;
+
+ error = xfs_btree_query_range(cur, low, high,
+ &xfs_btree_has_record_helper, NULL);
+ if (error == XFS_BTREE_QUERY_RANGE_ABORT) {
+ *exists = true;
+ return 0;
+ }
+ *exists = false;
+ return error;
+}
+
+/* Are there more records in this btree? */
+bool
+xfs_btree_has_more_records(
+ struct xfs_btree_cur *cur)
+{
+ struct xfs_btree_block *block;
+ struct xfs_buf *bp;
+
+ block = xfs_btree_get_block(cur, 0, &bp);
+
+ /* There are still records in this block. */
+ if (cur->bc_ptrs[0] < xfs_btree_get_numrecs(block))
+ return true;
+
+ /* There are more record blocks. */
+ if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
+ return block->bb_u.l.bb_rightsib != cpu_to_be64(NULLFSBLOCK);
+ else
+ return block->bb_u.s.bb_rightsib != cpu_to_be32(NULLAGBLOCK);
+}