diff options
| -rw-r--r-- | fs/bcachefs/fs.c | 225 |
1 files changed, 112 insertions, 113 deletions
diff --git a/fs/bcachefs/fs.c b/fs/bcachefs/fs.c index f5a9f9e8c457..0f1d61aab90b 100644 --- a/fs/bcachefs/fs.c +++ b/fs/bcachefs/fs.c @@ -1274,6 +1274,8 @@ static int bch2_fill_extent(struct bch_fs *c, struct bkey_s_c k = bkey_i_to_s_c(fe->kbuf.k); unsigned flags = fe->flags; + BUG_ON(!k.k->size); + if (bkey_extent_is_direct_data(k.k)) { struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k); const union bch_extent_entry *entry; @@ -1326,36 +1328,6 @@ 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) -{ - s64 offset_into_extent = iter->pos.offset - bkey_start_offset(k.k); - unsigned sectors = k.k->size - offset_into_extent; - - bch2_bkey_buf_reassemble(&cur->kbuf, trans->c, k); - - enum btree_id data_btree = BTREE_ID_extents; - int 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_t(unsigned, 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; -} - /* * Scan a range of an inode for data in pagecache. * @@ -1371,13 +1343,19 @@ bch2_fiemap_hole_pagecache(struct inode *vinode, u64 *start, u64 *end, dstart = bch2_seek_pagecache_data(vinode, *start, *end, 0, nonblock); if (dstart < 0) return dstart; - if (dstart >= *end) - return -ENOENT; + + if (dstart == *end) { + *start = dstart; + return 0; + } dend = bch2_seek_pagecache_hole(vinode, dstart, *end, 0, nonblock); if (dend < 0) return dend; + /* race */ + BUG_ON(dstart == dend); + *start = dstart; *end = dend; return 0; @@ -1387,18 +1365,15 @@ bch2_fiemap_hole_pagecache(struct inode *vinode, u64 *start, u64 *end, * Scan a range of pagecache that corresponds to a file mapping hole in the * extent btree. If data is found, fake up an extent key so it looks like a * delalloc extent to the rest of the fiemap processing code. - * - * Returns 0 if cached data was found, -ENOENT if not. */ static int -bch2_fiemap_hole(struct btree_trans *trans, struct inode *vinode, u64 start, - u64 end, struct bch_fiemap_extent *cur) +bch2_next_fiemap_pagecache_extent(struct btree_trans *trans, struct bch_inode_info *inode, + u64 start, u64 end, struct bch_fiemap_extent *cur) { - struct bch_fs *c = vinode->i_sb->s_fs_info; - struct bch_inode_info *ei = to_bch_ei(vinode); + struct bch_fs *c = trans->c; struct bkey_i_extent *delextent; struct bch_extent_ptr ptr = {}; - loff_t dstart = start, dend = end; + loff_t dstart = start << 9, dend = end << 9; int ret; /* @@ -1411,13 +1386,10 @@ bch2_fiemap_hole(struct btree_trans *trans, struct inode *vinode, u64 start, * fundamentally racy with writeback anyways. Therefore, just report the * range as delalloc regardless of whether we have to cycle trans locks. */ - ret = bch2_fiemap_hole_pagecache(vinode, &dstart, &dend, true); - if (ret == -EAGAIN) { - /* open coded drop_locks_do() to relock even on error */ - bch2_trans_unlock(trans); - ret = bch2_fiemap_hole_pagecache(vinode, &dstart, &dend, false); - bch2_trans_relock(trans); - } + ret = bch2_fiemap_hole_pagecache(&inode->v, &dstart, &dend, true); + if (ret == -EAGAIN) + ret = drop_locks_do(trans, + bch2_fiemap_hole_pagecache(&inode->v, &dstart, &dend, false)); if (ret < 0) return ret; @@ -1428,8 +1400,8 @@ bch2_fiemap_hole(struct btree_trans *trans, struct inode *vinode, u64 start, */ bch2_bkey_buf_realloc(&cur->kbuf, c, sizeof(*delextent) / sizeof(u64)); delextent = bkey_extent_init(cur->kbuf.k); - delextent->k.p = POS(ei->v.i_ino, dstart >> 9); - bch2_key_resize(&delextent->k, (dend - dstart) >> 9); + delextent->k.p = POS(inode->ei_inum.inum, dend >> 9); + delextent->k.size = (dend - dstart) >> 9; bch2_bkey_append_ptr(&delextent->k_i, ptr); cur->flags = FIEMAP_EXTENT_DELALLOC; @@ -1437,115 +1409,142 @@ bch2_fiemap_hole(struct btree_trans *trans, struct inode *vinode, u64 start, return 0; } +static int bch2_next_fiemap_extent(struct btree_trans *trans, + struct bch_inode_info *inode, + u64 start, u64 end, + struct bch_fiemap_extent *cur) +{ + u32 snapshot; + int ret = bch2_subvolume_get_snapshot(trans, inode->ei_inum.subvol, &snapshot); + if (ret) + return ret; + + struct btree_iter iter; + bch2_trans_iter_init(trans, &iter, BTREE_ID_extents, + SPOS(inode->ei_inum.inum, start, snapshot), 0); + + struct bkey_s_c k = + bch2_btree_iter_peek_max(trans, &iter, POS(inode->ei_inum.inum, end)); + ret = bkey_err(k); + if (ret) + goto err; + + ret = bch2_next_fiemap_pagecache_extent(trans, inode, start, end, cur); + if (ret) + goto err; + + struct bpos pagecache_start = bkey_start_pos(&cur->kbuf.k->k); + + /* + * Does the pagecache or the btree take precedence? + * + * It _should_ be the pagecache, so that we correctly report delalloc + * extents when dirty in the pagecache (we're COW, after all). + * + * But we'd have to add per-sector writeback tracking to + * bch_folio_state, otherwise we report delalloc extents for clean + * cached data in the pagecache. + * + * We should do this, but even then fiemap won't report stable mappings: + * on bcachefs data moves around in the background (copygc, rebalance) + * and we don't provide a way for userspace to lock that out. + */ + if (k.k && + bkey_le(bpos_max(iter.pos, bkey_start_pos(k.k)), + pagecache_start)) { + bch2_bkey_buf_reassemble(&cur->kbuf, trans->c, k); + bch2_cut_front(iter.pos, cur->kbuf.k); + bch2_cut_back(POS(inode->ei_inum.inum, end), cur->kbuf.k); + cur->flags = 0; + } else if (k.k) { + bch2_cut_back(bkey_start_pos(k.k), cur->kbuf.k); + } + + if (cur->kbuf.k->k.type == KEY_TYPE_reflink_p) { + unsigned sectors = cur->kbuf.k->k.size; + s64 offset_into_extent = 0; + enum btree_id data_btree = BTREE_ID_extents; + int ret = bch2_read_indirect_extent(trans, &data_btree, &offset_into_extent, + &cur->kbuf); + if (ret) + goto err; + + struct bkey_i *k = cur->kbuf.k; + sectors = min_t(unsigned, sectors, k->k.size - offset_into_extent); + + bch2_cut_front(POS(k->k.p.inode, + bkey_start_offset(&k->k) + offset_into_extent), + k); + bch2_key_resize(&k->k, sectors); + k->k.p = iter.pos; + k->k.p.offset += k->k.size; + } +err: + bch2_trans_iter_exit(trans, &iter); + return ret; +} + static int bch2_fiemap(struct inode *vinode, struct fiemap_extent_info *info, u64 start, u64 len) { struct bch_fs *c = vinode->i_sb->s_fs_info; struct bch_inode_info *ei = to_bch_ei(vinode); struct btree_trans *trans; - struct btree_iter iter; - struct bkey_s_c k; struct bch_fiemap_extent cur, prev; - bool have_extent = false; int ret = 0; ret = fiemap_prep(&ei->v, info, start, &len, 0); if (ret) return ret; - struct bpos end = POS(ei->v.i_ino, (start + len) >> 9); if (start + len < start) return -EINVAL; start >>= 9; + u64 end = (start + len) >> 9; bch2_bkey_buf_init(&cur.kbuf); bch2_bkey_buf_init(&prev.kbuf); - trans = bch2_trans_get(c); - - bch2_trans_iter_init(trans, &iter, BTREE_ID_extents, - POS(ei->v.i_ino, start), 0); + bkey_init(&prev.kbuf.k->k); - while (!ret || bch2_err_matches(ret, BCH_ERR_transaction_restart)) { - bool have_delalloc = false; - - bch2_trans_begin(trans); + trans = bch2_trans_get(c); - u32 snapshot; - ret = bch2_subvolume_get_snapshot(trans, ei->ei_inum.subvol, &snapshot); + while (start < end) { + ret = lockrestart_do(trans, + bch2_next_fiemap_extent(trans, ei, start, end, &cur)); if (ret) - continue; - - bch2_btree_iter_set_snapshot(trans, &iter, snapshot); + goto err; - k = bch2_btree_iter_peek_max(trans, &iter, end); - ret = bkey_err(k); - if (ret) - continue; + BUG_ON(bkey_start_offset(&cur.kbuf.k->k) < start); + BUG_ON(cur.kbuf.k->k.p.offset > end); - if (!k.k) + if (bkey_start_offset(&cur.kbuf.k->k) == end) break; - /* - * If a hole exists before the start of the extent key, scan the - * range for pagecache data that might be pending writeback and - * thus not yet exist in the extent tree. - */ - if (iter.pos.offset > start) { - ret = bch2_fiemap_hole(trans, vinode, start << 9, - iter.pos.offset << 9, &cur); - if (!ret) - have_delalloc = true; - else if (ret != -ENOENT) - break; - } - - /* process the current key if there's no delalloc to report */ - if (!have_delalloc) { - if (!bkey_extent_is_data(k.k) && - k.k->type != KEY_TYPE_reservation) { - start = bkey_start_offset(k.k) + k.k->size; - bch2_btree_iter_advance(trans, &iter); - continue; - } - - ret = bch2_fiemap_extent(trans, &iter, k, &cur); - if (ret) - break; - } - - /* - * Store the current extent in prev so we can flag the last - * extent on the way out. - */ - bch2_bkey_buf_realloc(&prev.kbuf, c, cur.kbuf.k->k.u64s); start = cur.kbuf.k->k.p.offset; - if (have_extent) { + if (!bkey_deleted(&prev.kbuf.k->k)) { bch2_trans_unlock(trans); ret = bch2_fill_extent(c, info, &prev); if (ret) - break; + goto err; } - bkey_copy(prev.kbuf.k, cur.kbuf.k); + bch2_bkey_buf_copy(&prev.kbuf, c, cur.kbuf.k); prev.flags = cur.flags; - have_extent = true; - - bch2_btree_iter_set_pos(trans, &iter, POS(iter.pos.inode, start)); } - bch2_trans_iter_exit(trans, &iter); - if (!ret && have_extent) { + if (!bkey_deleted(&prev.kbuf.k->k)) { bch2_trans_unlock(trans); prev.flags |= FIEMAP_EXTENT_LAST; ret = bch2_fill_extent(c, info, &prev); } - +err: bch2_trans_put(trans); bch2_bkey_buf_exit(&cur.kbuf, c); bch2_bkey_buf_exit(&prev.kbuf, c); - return ret < 0 ? ret : 0; + + return bch2_err_class(ret < 0 ? ret : 0); } static const struct vm_operations_struct bch_vm_ops = { |