diff options
Diffstat (limited to 'fs/xfs/xfs_btree.c')
| -rw-r--r-- | fs/xfs/xfs_btree.c | 170 |
1 files changed, 152 insertions, 18 deletions
diff --git a/fs/xfs/xfs_btree.c b/fs/xfs/xfs_btree.c index 7a2b4da3c0d..5690e102243 100644 --- a/fs/xfs/xfs_btree.c +++ b/fs/xfs/xfs_btree.c @@ -855,6 +855,41 @@ xfs_btree_readahead( return xfs_btree_readahead_sblock(cur, lr, block); } +STATIC xfs_daddr_t +xfs_btree_ptr_to_daddr( + struct xfs_btree_cur *cur, + union xfs_btree_ptr *ptr) +{ + if (cur->bc_flags & XFS_BTREE_LONG_PTRS) { + ASSERT(ptr->l != cpu_to_be64(NULLDFSBNO)); + + return XFS_FSB_TO_DADDR(cur->bc_mp, be64_to_cpu(ptr->l)); + } else { + ASSERT(cur->bc_private.a.agno != NULLAGNUMBER); + ASSERT(ptr->s != cpu_to_be32(NULLAGBLOCK)); + + return XFS_AGB_TO_DADDR(cur->bc_mp, cur->bc_private.a.agno, + be32_to_cpu(ptr->s)); + } +} + +/* + * Readahead @count btree blocks at the given @ptr location. + * + * We don't need to care about long or short form btrees here as we have a + * method of converting the ptr directly to a daddr available to us. + */ +STATIC void +xfs_btree_readahead_ptr( + struct xfs_btree_cur *cur, + union xfs_btree_ptr *ptr, + xfs_extlen_t count) +{ + xfs_buf_readahead(cur->bc_mp->m_ddev_targp, + xfs_btree_ptr_to_daddr(cur, ptr), + cur->bc_mp->m_bsize * count, cur->bc_ops->buf_ops); +} + /* * Set the buffer for level "lev" in the cursor to bp, releasing * any previous buffer. @@ -1073,24 +1108,6 @@ xfs_btree_buf_to_ptr( } } -STATIC xfs_daddr_t -xfs_btree_ptr_to_daddr( - struct xfs_btree_cur *cur, - union xfs_btree_ptr *ptr) -{ - if (cur->bc_flags & XFS_BTREE_LONG_PTRS) { - ASSERT(ptr->l != cpu_to_be64(NULLDFSBNO)); - - return XFS_FSB_TO_DADDR(cur->bc_mp, be64_to_cpu(ptr->l)); - } else { - ASSERT(cur->bc_private.a.agno != NULLAGNUMBER); - ASSERT(ptr->s != cpu_to_be32(NULLAGBLOCK)); - - return XFS_AGB_TO_DADDR(cur->bc_mp, cur->bc_private.a.agno, - be32_to_cpu(ptr->s)); - } -} - STATIC void xfs_btree_set_refs( struct xfs_btree_cur *cur, @@ -3869,3 +3886,120 @@ xfs_btree_get_rec( *stat = 1; return 0; } + +/* + * Change the owner of a btree. + * + * The mechanism we use here is ordered buffer logging. Because we don't know + * how many buffers were are going to need to modify, we don't really want to + * have to make transaction reservations for the worst case of every buffer in a + * full size btree as that may be more space that we can fit in the log.... + * + * We do the btree walk in the most optimal manner possible - we have sibling + * pointers so we can just walk all the blocks on each level from left to right + * in a single pass, and then move to the next level and do the same. We can + * also do readahead on the sibling pointers to get IO moving more quickly, + * though for slow disks this is unlikely to make much difference to performance + * as the amount of CPU work we have to do before moving to the next block is + * relatively small. + * + * For each btree block that we load, modify the owner appropriately, set the + * buffer as an ordered buffer and log it appropriately. We need to ensure that + * we mark the region we change dirty so that if the buffer is relogged in + * a subsequent transaction the changes we make here as an ordered buffer are + * correctly relogged in that transaction. If we are in recovery context, then + * just queue the modified buffer as delayed write buffer so the transaction + * recovery completion writes the changes to disk. + */ +static int +xfs_btree_block_change_owner( + struct xfs_btree_cur *cur, + int level, + __uint64_t new_owner, + struct list_head *buffer_list) +{ + struct xfs_btree_block *block; + struct xfs_buf *bp; + union xfs_btree_ptr rptr; + + /* do right sibling readahead */ + xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA); + + /* modify the owner */ + block = xfs_btree_get_block(cur, level, &bp); + if (cur->bc_flags & XFS_BTREE_LONG_PTRS) + block->bb_u.l.bb_owner = cpu_to_be64(new_owner); + else + block->bb_u.s.bb_owner = cpu_to_be32(new_owner); + + /* + * If the block is a root block hosted in an inode, we might not have a + * buffer pointer here and we shouldn't attempt to log the change as the + * information is already held in the inode and discarded when the root + * block is formatted into the on-disk inode fork. We still change it, + * though, so everything is consistent in memory. + */ + if (bp) { + if (cur->bc_tp) { + xfs_trans_ordered_buf(cur->bc_tp, bp); + xfs_btree_log_block(cur, bp, XFS_BB_OWNER); + } else { + xfs_buf_delwri_queue(bp, buffer_list); + } + } else { + ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE); + ASSERT(level == cur->bc_nlevels - 1); + } + + /* now read rh sibling block for next iteration */ + xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB); + if (xfs_btree_ptr_is_null(cur, &rptr)) + return ENOENT; + + return xfs_btree_lookup_get_block(cur, level, &rptr, &block); +} + +int +xfs_btree_change_owner( + struct xfs_btree_cur *cur, + __uint64_t new_owner, + struct list_head *buffer_list) +{ + union xfs_btree_ptr lptr; + int level; + struct xfs_btree_block *block = NULL; + int error = 0; + + cur->bc_ops->init_ptr_from_cur(cur, &lptr); + + /* for each level */ + for (level = cur->bc_nlevels - 1; level >= 0; level--) { + /* grab the left hand block */ + error = xfs_btree_lookup_get_block(cur, level, &lptr, &block); + if (error) + return error; + + /* readahead the left most block for the next level down */ + if (level > 0) { + union xfs_btree_ptr *ptr; + + ptr = xfs_btree_ptr_addr(cur, 1, block); + xfs_btree_readahead_ptr(cur, ptr, 1); + + /* save for the next iteration of the loop */ + lptr = *ptr; + } + + /* for each buffer in the level */ + do { + error = xfs_btree_block_change_owner(cur, level, + new_owner, + buffer_list); + } while (!error); + + if (error != ENOENT) + return error; + } + + return 0; +} |