[XFS] implement generic xfs_btree_rshift
Make the btree right shift code generic. Based on a patch from David Chinner with lots of changes to follow the original btree implementations more closely. While this loses some of the generic helper routines for inserting/moving/removing records it also solves some of the one off bugs in the original code and makes it easier to verify. SGI-PV: 985583 SGI-Modid: xfs-linux-melb:xfs-kern:32196a Signed-off-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Lachlan McIlroy <lachlan@sgi.com> Signed-off-by: Bill O'Donnell <billodo@sgi.com> Signed-off-by: David Chinner <david@fromorbit.com>
This commit is contained in:
Christoph Hellwig
committed by
Lachlan McIlroy
Lachlan McIlroy
parent
278d0ca14e
commit
9eaead51be
@@ -1117,6 +1117,77 @@ xfs_btree_copy_recs(
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memcpy(dst_rec, src_rec, numrecs * cur->bc_ops->rec_len);
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}
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/*
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* Copy block pointers from one btree block to another.
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*/
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STATIC void
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xfs_btree_copy_ptrs(
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struct xfs_btree_cur *cur,
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union xfs_btree_ptr *dst_ptr,
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union xfs_btree_ptr *src_ptr,
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int numptrs)
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{
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ASSERT(numptrs >= 0);
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memcpy(dst_ptr, src_ptr, numptrs * xfs_btree_ptr_len(cur));
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}
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/*
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* Shift keys one index left/right inside a single btree block.
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*/
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STATIC void
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xfs_btree_shift_keys(
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struct xfs_btree_cur *cur,
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union xfs_btree_key *key,
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int dir,
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int numkeys)
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{
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char *dst_key;
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ASSERT(numkeys >= 0);
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ASSERT(dir == 1 || dir == -1);
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dst_key = (char *)key + (dir * cur->bc_ops->key_len);
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memmove(dst_key, key, numkeys * cur->bc_ops->key_len);
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}
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/*
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* Shift records one index left/right inside a single btree block.
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*/
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STATIC void
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xfs_btree_shift_recs(
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struct xfs_btree_cur *cur,
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union xfs_btree_rec *rec,
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int dir,
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int numrecs)
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{
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char *dst_rec;
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ASSERT(numrecs >= 0);
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ASSERT(dir == 1 || dir == -1);
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dst_rec = (char *)rec + (dir * cur->bc_ops->rec_len);
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memmove(dst_rec, rec, numrecs * cur->bc_ops->rec_len);
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}
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/*
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* Shift block pointers one index left/right inside a single btree block.
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*/
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STATIC void
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xfs_btree_shift_ptrs(
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struct xfs_btree_cur *cur,
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union xfs_btree_ptr *ptr,
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int dir,
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int numptrs)
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{
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char *dst_ptr;
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ASSERT(numptrs >= 0);
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ASSERT(dir == 1 || dir == -1);
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dst_ptr = (char *)ptr + (dir * xfs_btree_ptr_len(cur));
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memmove(dst_ptr, ptr, numptrs * xfs_btree_ptr_len(cur));
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}
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/*
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* Log key values from the btree block.
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*/
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@@ -1162,6 +1233,79 @@ xfs_btree_log_recs(
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XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
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}
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/*
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* Log block pointer fields from a btree block (nonleaf).
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*/
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STATIC void
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xfs_btree_log_ptrs(
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struct xfs_btree_cur *cur, /* btree cursor */
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struct xfs_buf *bp, /* buffer containing btree block */
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int first, /* index of first pointer to log */
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int last) /* index of last pointer to log */
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{
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XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
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XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
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if (bp) {
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struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
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int level = xfs_btree_get_level(block);
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xfs_trans_log_buf(cur->bc_tp, bp,
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xfs_btree_ptr_offset(cur, first, level),
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xfs_btree_ptr_offset(cur, last + 1, level) - 1);
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} else {
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xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
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xfs_ilog_fbroot(cur->bc_private.b.whichfork));
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}
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XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
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}
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/*
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* Log fields from a btree block header.
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*/
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STATIC void
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xfs_btree_log_block(
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struct xfs_btree_cur *cur, /* btree cursor */
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struct xfs_buf *bp, /* buffer containing btree block */
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int fields) /* mask of fields: XFS_BB_... */
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{
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int first; /* first byte offset logged */
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int last; /* last byte offset logged */
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static const short soffsets[] = { /* table of offsets (short) */
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offsetof(struct xfs_btree_sblock, bb_magic),
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offsetof(struct xfs_btree_sblock, bb_level),
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offsetof(struct xfs_btree_sblock, bb_numrecs),
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offsetof(struct xfs_btree_sblock, bb_leftsib),
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offsetof(struct xfs_btree_sblock, bb_rightsib),
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sizeof(struct xfs_btree_sblock)
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};
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static const short loffsets[] = { /* table of offsets (long) */
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offsetof(struct xfs_btree_lblock, bb_magic),
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offsetof(struct xfs_btree_lblock, bb_level),
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offsetof(struct xfs_btree_lblock, bb_numrecs),
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offsetof(struct xfs_btree_lblock, bb_leftsib),
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offsetof(struct xfs_btree_lblock, bb_rightsib),
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sizeof(struct xfs_btree_lblock)
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};
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XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
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XFS_BTREE_TRACE_ARGBI(cur, bp, fields);
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if (bp) {
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xfs_btree_offsets(fields,
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(cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
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loffsets : soffsets,
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XFS_BB_NUM_BITS, &first, &last);
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xfs_trans_log_buf(cur->bc_tp, bp, first, last);
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} else {
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xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
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xfs_ilog_fbroot(cur->bc_private.b.whichfork));
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}
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XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
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}
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/*
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* Increment cursor by one record at the level.
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* For nonzero levels the leaf-ward information is untouched.
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@@ -1368,7 +1512,6 @@ error0:
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return error;
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}
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STATIC int
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xfs_btree_lookup_get_block(
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struct xfs_btree_cur *cur, /* btree cursor */
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@@ -1697,3 +1840,177 @@ error0:
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return error;
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}
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/*
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* Move 1 record right from cur/level if possible.
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* Update cur to reflect the new path.
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*/
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int /* error */
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xfs_btree_rshift(
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struct xfs_btree_cur *cur,
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int level,
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int *stat) /* success/failure */
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{
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union xfs_btree_key key; /* btree key */
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struct xfs_buf *lbp; /* left buffer pointer */
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struct xfs_btree_block *left; /* left btree block */
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struct xfs_buf *rbp; /* right buffer pointer */
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struct xfs_btree_block *right; /* right btree block */
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struct xfs_btree_cur *tcur; /* temporary btree cursor */
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union xfs_btree_ptr rptr; /* right block pointer */
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union xfs_btree_key *rkp; /* right btree key */
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int rrecs; /* right record count */
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int lrecs; /* left record count */
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int error; /* error return value */
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int i; /* loop counter */
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XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
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XFS_BTREE_TRACE_ARGI(cur, level);
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if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
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(level == cur->bc_nlevels - 1))
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goto out0;
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/* Set up variables for this block as "left". */
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left = xfs_btree_get_block(cur, level, &lbp);
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#ifdef DEBUG
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error = xfs_btree_check_block(cur, left, level, lbp);
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if (error)
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goto error0;
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#endif
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/* If we've got no right sibling then we can't shift an entry right. */
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xfs_btree_get_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
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if (xfs_btree_ptr_is_null(cur, &rptr))
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goto out0;
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/*
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* If the cursor entry is the one that would be moved, don't
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* do it... it's too complicated.
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*/
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lrecs = xfs_btree_get_numrecs(left);
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if (cur->bc_ptrs[level] >= lrecs)
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goto out0;
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/* Set up the right neighbor as "right". */
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error = xfs_btree_read_buf_block(cur, &rptr, level, 0, &right, &rbp);
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if (error)
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goto error0;
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/* If it's full, it can't take another entry. */
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rrecs = xfs_btree_get_numrecs(right);
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if (rrecs == cur->bc_ops->get_maxrecs(cur, level))
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goto out0;
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XFS_BTREE_STATS_INC(cur, rshift);
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XFS_BTREE_STATS_ADD(cur, moves, rrecs);
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/*
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* Make a hole at the start of the right neighbor block, then
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* copy the last left block entry to the hole.
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*/
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if (level > 0) {
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/* It's a nonleaf. make a hole in the keys and ptrs */
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union xfs_btree_key *lkp;
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union xfs_btree_ptr *lpp;
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union xfs_btree_ptr *rpp;
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lkp = xfs_btree_key_addr(cur, lrecs, left);
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lpp = xfs_btree_ptr_addr(cur, lrecs, left);
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rkp = xfs_btree_key_addr(cur, 1, right);
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rpp = xfs_btree_ptr_addr(cur, 1, right);
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#ifdef DEBUG
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for (i = rrecs - 1; i >= 0; i--) {
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error = xfs_btree_check_ptr(cur, rpp, i, level);
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if (error)
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goto error0;
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}
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#endif
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xfs_btree_shift_keys(cur, rkp, 1, rrecs);
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xfs_btree_shift_ptrs(cur, rpp, 1, rrecs);
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#ifdef DEBUG
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error = xfs_btree_check_ptr(cur, lpp, 0, level);
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if (error)
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goto error0;
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#endif
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/* Now put the new data in, and log it. */
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xfs_btree_copy_keys(cur, rkp, lkp, 1);
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xfs_btree_copy_ptrs(cur, rpp, lpp, 1);
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xfs_btree_log_keys(cur, rbp, 1, rrecs + 1);
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xfs_btree_log_ptrs(cur, rbp, 1, rrecs + 1);
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xfs_btree_check_key(cur->bc_btnum, rkp,
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xfs_btree_key_addr(cur, 2, right));
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} else {
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/* It's a leaf. make a hole in the records */
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union xfs_btree_rec *lrp;
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union xfs_btree_rec *rrp;
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lrp = xfs_btree_rec_addr(cur, lrecs, left);
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rrp = xfs_btree_rec_addr(cur, 1, right);
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xfs_btree_shift_recs(cur, rrp, 1, rrecs);
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/* Now put the new data in, and log it. */
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xfs_btree_copy_recs(cur, rrp, lrp, 1);
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xfs_btree_log_recs(cur, rbp, 1, rrecs + 1);
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cur->bc_ops->init_key_from_rec(&key, rrp);
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rkp = &key;
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xfs_btree_check_rec(cur->bc_btnum, rrp,
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xfs_btree_rec_addr(cur, 2, right));
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}
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/*
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* Decrement and log left's numrecs, bump and log right's numrecs.
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*/
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xfs_btree_set_numrecs(left, --lrecs);
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xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS);
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xfs_btree_set_numrecs(right, ++rrecs);
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xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS);
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/*
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* Using a temporary cursor, update the parent key values of the
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* block on the right.
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*/
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error = xfs_btree_dup_cursor(cur, &tcur);
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if (error)
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goto error0;
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i = xfs_btree_lastrec(tcur, level);
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XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
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error = xfs_btree_increment(tcur, level, &i);
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if (error)
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goto error1;
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error = xfs_btree_updkey(tcur, rkp, level + 1);
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if (error)
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goto error1;
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xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
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XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
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*stat = 1;
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return 0;
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out0:
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XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
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*stat = 0;
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return 0;
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error0:
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XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
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return error;
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error1:
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XFS_BTREE_TRACE_CURSOR(tcur, XBT_ERROR);
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xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
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return error;
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}
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