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author | Christoph Hellwig <hch@infradead.org> | 2008-10-30 16:57:16 +1100 |
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committer | Lachlan McIlroy <lachlan@sgi.com> | 2008-10-30 16:57:16 +1100 |
commit | 344207ce8474b79be331eb93e6df4cb5bdd48ab2 (patch) | |
tree | 7858f63c359e2695a6c368a73b078ff183345922 /fs/xfs/xfs_btree.c | |
parent | f5eb8e7ca58bc1e92436614444006120d21668ba (diff) | |
download | kernel_samsung_espresso10-344207ce8474b79be331eb93e6df4cb5bdd48ab2.zip kernel_samsung_espresso10-344207ce8474b79be331eb93e6df4cb5bdd48ab2.tar.gz kernel_samsung_espresso10-344207ce8474b79be331eb93e6df4cb5bdd48ab2.tar.bz2 |
[XFS] implement semi-generic xfs_btree_new_root
From: Dave Chinner <dgc@sgi.com>
Add a xfs_btree_new_root helper for the alloc and ialloc btrees. The bmap
btree needs it's own version and is not converted.
[hch: split out from bigger patch and minor adaptions]
SGI-PV: 985583
SGI-Modid: xfs-linux-melb:xfs-kern:32200a
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>
Diffstat (limited to 'fs/xfs/xfs_btree.c')
-rw-r--r-- | fs/xfs/xfs_btree.c | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/fs/xfs/xfs_btree.c b/fs/xfs/xfs_btree.c index 8057669..8de884c 100644 --- a/fs/xfs/xfs_btree.c +++ b/fs/xfs/xfs_btree.c @@ -2467,3 +2467,132 @@ error0: XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR); return error; } + +/* + * Allocate a new root block, fill it in. + */ +int /* error */ +xfs_btree_new_root( + struct xfs_btree_cur *cur, /* btree cursor */ + int *stat) /* success/failure */ +{ + struct xfs_btree_block *block; /* one half of the old root block */ + struct xfs_buf *bp; /* buffer containing block */ + int error; /* error return value */ + struct xfs_buf *lbp; /* left buffer pointer */ + struct xfs_btree_block *left; /* left btree block */ + struct xfs_buf *nbp; /* new (root) buffer */ + struct xfs_btree_block *new; /* new (root) btree block */ + int nptr; /* new value for key index, 1 or 2 */ + struct xfs_buf *rbp; /* right buffer pointer */ + struct xfs_btree_block *right; /* right btree block */ + union xfs_btree_ptr rptr; + union xfs_btree_ptr lptr; + + XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY); + XFS_BTREE_STATS_INC(cur, newroot); + + /* initialise our start point from the cursor */ + cur->bc_ops->init_ptr_from_cur(cur, &rptr); + + /* Allocate the new block. If we can't do it, we're toast. Give up. */ + error = cur->bc_ops->alloc_block(cur, &rptr, &lptr, 1, 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, + cur->bc_nlevels - 1, 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, + cur->bc_nlevels - 1, 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->bc_nlevels, 2, new); + xfs_btree_log_block(cur, nbp, XFS_BB_ALL_BITS); + ASSERT(!xfs_btree_ptr_is_null(cur, &lptr) && + !xfs_btree_ptr_is_null(cur, &rptr)); + + /* Fill in the key data in the new root. */ + if (xfs_btree_get_level(left) > 0) { + xfs_btree_copy_keys(cur, + xfs_btree_key_addr(cur, 1, new), + xfs_btree_key_addr(cur, 1, left), 1); + xfs_btree_copy_keys(cur, + xfs_btree_key_addr(cur, 2, new), + xfs_btree_key_addr(cur, 1, right), 1); + } else { + cur->bc_ops->init_key_from_rec( + xfs_btree_key_addr(cur, 1, new), + xfs_btree_rec_addr(cur, 1, left)); + cur->bc_ops->init_key_from_rec( + xfs_btree_key_addr(cur, 2, new), + xfs_btree_rec_addr(cur, 1, right)); + } + xfs_btree_log_keys(cur, nbp, 1, 2); + + /* Fill in the pointer data in the new root. */ + xfs_btree_copy_ptrs(cur, + xfs_btree_ptr_addr(cur, 1, new), &lptr, 1); + xfs_btree_copy_ptrs(cur, + xfs_btree_ptr_addr(cur, 2, new), &rptr, 1); + xfs_btree_log_ptrs(cur, nbp, 1, 2); + + /* Fix up the cursor. */ + xfs_btree_setbuf(cur, cur->bc_nlevels, nbp); + cur->bc_ptrs[cur->bc_nlevels] = nptr; + cur->bc_nlevels++; + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); + *stat = 1; + return 0; +error0: + XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR); + return error; +out0: + XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT); + *stat = 0; + return 0; +} |