diff options
| -rw-r--r-- | fs/nilfs2/btree.c | 94 |
1 files changed, 68 insertions, 26 deletions
diff --git a/fs/nilfs2/btree.c b/fs/nilfs2/btree.c index 4669389bf686..1b5321c0bcac 100644 --- a/fs/nilfs2/btree.c +++ b/fs/nilfs2/btree.c @@ -66,32 +66,6 @@ static void nilfs_btree_free_path(struct nilfs_btree_path *path) /* * B-tree node operations */ -static int nilfs_btree_get_block(const struct nilfs_bmap *btree, __u64 ptr, - struct buffer_head **bhp) -{ - struct address_space *btnc = &NILFS_BMAP_I(btree)->i_btnode_cache; - struct buffer_head *bh; - sector_t pbn = 0; - int err; - - err = nilfs_btnode_submit_block(btnc, ptr, pbn, READ, bhp, &pbn); - if (err) - return err == -EEXIST ? 0 : err; - - bh = *bhp; - wait_on_buffer(bh); - if (!buffer_uptodate(bh)) { - brelse(bh); - return -EIO; - } - if (nilfs_btree_broken_node_block(bh)) { - clear_buffer_uptodate(bh); - brelse(bh); - return -EINVAL; - } - return 0; -} - static int nilfs_btree_get_new_block(const struct nilfs_bmap *btree, __u64 ptr, struct buffer_head **bhp) { @@ -452,6 +426,74 @@ nilfs_btree_bad_node(struct nilfs_btree_node *node, int level) return 0; } +struct nilfs_btree_readahead_info { + struct nilfs_btree_node *node; /* parent node */ + int max_ra_blocks; /* max nof blocks to read ahead */ + int index; /* current index on the parent node */ + int ncmax; /* nof children in the parent node */ +}; + +static int __nilfs_btree_get_block(const struct nilfs_bmap *btree, __u64 ptr, + struct buffer_head **bhp, + const struct nilfs_btree_readahead_info *ra) +{ + struct address_space *btnc = &NILFS_BMAP_I(btree)->i_btnode_cache; + struct buffer_head *bh, *ra_bh; + sector_t submit_ptr = 0; + int ret; + + ret = nilfs_btnode_submit_block(btnc, ptr, 0, READ, &bh, &submit_ptr); + if (ret) { + if (ret != -EEXIST) + return ret; + goto out_check; + } + + if (ra) { + int i, n; + __u64 ptr2; + + /* read ahead sibling nodes */ + for (n = ra->max_ra_blocks, i = ra->index + 1; + n > 0 && i < ra->ncmax; n--, i++) { + ptr2 = nilfs_btree_node_get_ptr(ra->node, i, ra->ncmax); + + ret = nilfs_btnode_submit_block(btnc, ptr2, 0, READA, + &ra_bh, &submit_ptr); + if (likely(!ret || ret == -EEXIST)) + brelse(ra_bh); + else if (ret != -EBUSY) + break; + if (!buffer_locked(bh)) + goto out_no_wait; + } + } + + wait_on_buffer(bh); + + out_no_wait: + if (!buffer_uptodate(bh)) { + brelse(bh); + return -EIO; + } + + out_check: + if (nilfs_btree_broken_node_block(bh)) { + clear_buffer_uptodate(bh); + brelse(bh); + return -EINVAL; + } + + *bhp = bh; + return 0; +} + +static int nilfs_btree_get_block(const struct nilfs_bmap *btree, __u64 ptr, + struct buffer_head **bhp) +{ + return __nilfs_btree_get_block(btree, ptr, bhp, NULL); +} + static int nilfs_btree_do_lookup(const struct nilfs_bmap *btree, struct nilfs_btree_path *path, __u64 key, __u64 *ptrp, int minlevel) |