The bulk of the loop in bch2_fiemap() involves processing the current extent key from the iter, including following indirections and trimming the extent size and such. This patch makes a few changes to reduce the size of the loop and facilitate future changes to support delalloc extents.
Define a new bch_fiemap_extent structure to wrap the bkey buffer that holds the extent key to report to userspace along with associated fiemap flags. Update bch2_fill_extent() to take the bch_fiemap_extent as a param instead of the individual fields. Finally, lift the bulk of the extent processing into a bch2_fiemap_extent() helper that takes the current key and formats the bch_fiemap_extent appropriately for the fill function. No functional changes intended by this patch. Signed-off-by: Brian Foster <[email protected]> --- fs/bcachefs/fs.c | 90 +++++++++++++++++++++++++++++------------------- 1 file changed, 55 insertions(+), 35 deletions(-) diff --git a/fs/bcachefs/fs.c b/fs/bcachefs/fs.c index c9f426905ef9..1364f491af87 100644 --- a/fs/bcachefs/fs.c +++ b/fs/bcachefs/fs.c @@ -826,10 +826,18 @@ static int bch2_tmpfile(struct mnt_idmap *idmap, return finish_open_simple(file, 0); } +struct bch_fiemap_extent { + struct bkey_buf kbuf; + unsigned flags; +}; + static int bch2_fill_extent(struct bch_fs *c, struct fiemap_extent_info *info, - struct bkey_s_c k, unsigned flags) + struct bch_fiemap_extent *fe) { + struct bkey_s_c k = bkey_i_to_s_c(fe->kbuf.k); + unsigned flags = fe->flags; + if (bkey_extent_is_direct_data(k.k)) { struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k); const union bch_extent_entry *entry; @@ -882,6 +890,39 @@ static int bch2_fill_extent(struct bch_fs *c, } } +static int bch2_fiemap_extent(struct btree_trans *trans, + struct btree_iter *iter, struct bkey_s_c k, + struct bch_fiemap_extent *cur) +{ + unsigned offset_into_extent, sectors; + enum btree_id data_btree = BTREE_ID_extents; + int ret; + + offset_into_extent = iter->pos.offset - bkey_start_offset(k.k); + sectors = k.k->size - offset_into_extent; + + bch2_bkey_buf_reassemble(&cur->kbuf, trans->c, k); + + ret = bch2_read_indirect_extent(trans, &data_btree, &offset_into_extent, + &cur->kbuf); + if (ret) + return ret; + + k = bkey_i_to_s_c(cur->kbuf.k); + sectors = min(sectors, k.k->size - offset_into_extent); + + bch2_cut_front(POS(k.k->p.inode, + bkey_start_offset(k.k) + offset_into_extent), + cur->kbuf.k); + bch2_key_resize(&cur->kbuf.k->k, sectors); + cur->kbuf.k->k.p = iter->pos; + cur->kbuf.k->k.p.offset += cur->kbuf.k->k.size; + + cur->flags = 0; + + return 0; +} + static int bch2_fiemap(struct inode *vinode, struct fiemap_extent_info *info, u64 start, u64 len) { @@ -890,9 +931,8 @@ static int bch2_fiemap(struct inode *vinode, struct fiemap_extent_info *info, struct btree_trans *trans; struct btree_iter iter; struct bkey_s_c k; - struct bkey_buf cur, prev; + struct bch_fiemap_extent cur, prev; struct bpos end = POS(ei->v.i_ino, (start + len) >> 9); - unsigned offset_into_extent, sectors; bool have_extent = false; u32 snapshot; int ret = 0; @@ -906,8 +946,8 @@ static int bch2_fiemap(struct inode *vinode, struct fiemap_extent_info *info, start >>= 9; - bch2_bkey_buf_init(&cur); - bch2_bkey_buf_init(&prev); + bch2_bkey_buf_init(&cur.kbuf); + bch2_bkey_buf_init(&prev.kbuf); trans = bch2_trans_get(c); retry: bch2_trans_begin(trans); @@ -922,7 +962,6 @@ static int bch2_fiemap(struct inode *vinode, struct fiemap_extent_info *info, while (!(ret = btree_trans_too_many_iters(trans)) && (k = bch2_btree_iter_peek_upto(&iter, end)).k && !(ret = bkey_err(k))) { - enum btree_id data_btree = BTREE_ID_extents; if (!bkey_extent_is_data(k.k) && k.k->type != KEY_TYPE_reservation) { @@ -930,40 +969,21 @@ static int bch2_fiemap(struct inode *vinode, struct fiemap_extent_info *info, continue; } - offset_into_extent = iter.pos.offset - - bkey_start_offset(k.k); - sectors = k.k->size - offset_into_extent; - - bch2_bkey_buf_reassemble(&cur, c, k); - - ret = bch2_read_indirect_extent(trans, &data_btree, - &offset_into_extent, &cur); + ret = bch2_fiemap_extent(trans, &iter, k, &cur); if (ret) break; - - k = bkey_i_to_s_c(cur.k); - bch2_bkey_buf_realloc(&prev, c, k.k->u64s); - - sectors = min(sectors, k.k->size - offset_into_extent); - start = iter.pos.offset + sectors; - - bch2_cut_front(POS(k.k->p.inode, - bkey_start_offset(k.k) + - offset_into_extent), - cur.k); - bch2_key_resize(&cur.k->k, sectors); - cur.k->k.p = iter.pos; - cur.k->k.p.offset += cur.k->k.size; + bch2_bkey_buf_realloc(&prev.kbuf, c, cur.kbuf.k->k.u64s); + start = cur.kbuf.k->k.p.offset; if (have_extent) { bch2_trans_unlock(trans); - ret = bch2_fill_extent(c, info, - bkey_i_to_s_c(prev.k), 0); + ret = bch2_fill_extent(c, info, &prev); if (ret) break; } - bkey_copy(prev.k, cur.k); + bkey_copy(prev.kbuf.k, cur.kbuf.k); + prev.flags = cur.flags; have_extent = true; bch2_btree_iter_set_pos(&iter, POS(iter.pos.inode, start)); @@ -976,13 +996,13 @@ static int bch2_fiemap(struct inode *vinode, struct fiemap_extent_info *info, if (!ret && have_extent) { bch2_trans_unlock(trans); - ret = bch2_fill_extent(c, info, bkey_i_to_s_c(prev.k), - FIEMAP_EXTENT_LAST); + prev.flags |= FIEMAP_EXTENT_LAST; + ret = bch2_fill_extent(c, info, &prev); } bch2_trans_put(trans); - bch2_bkey_buf_exit(&cur, c); - bch2_bkey_buf_exit(&prev, c); + bch2_bkey_buf_exit(&cur.kbuf, c); + bch2_bkey_buf_exit(&prev.kbuf, c); return ret < 0 ? ret : 0; } -- 2.42.0
