diff options
Diffstat (limited to 'fs/btrfs/ioctl.c')
-rw-r--r-- | fs/btrfs/ioctl.c | 64 |
1 files changed, 54 insertions, 10 deletions
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index e82b4f3f490c..fa64a1127c97 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -527,8 +527,6 @@ static noinline int create_subvol(struct inode *dir, btrfs_set_root_otransid(root_item, trans->transid); btrfs_tree_unlock(leaf); - free_extent_buffer(leaf); - leaf = NULL; btrfs_set_root_dirid(root_item, new_dirid); @@ -537,8 +535,22 @@ static noinline int create_subvol(struct inode *dir, key.type = BTRFS_ROOT_ITEM_KEY; ret = btrfs_insert_root(trans, fs_info->tree_root, &key, root_item); - if (ret) + if (ret) { + /* + * Since we don't abort the transaction in this case, free the + * tree block so that we don't leak space and leave the + * filesystem in an inconsistent state (an extent item in the + * extent tree without backreferences). Also no need to have + * the tree block locked since it is not in any tree at this + * point, so no other task can find it and use it. + */ + btrfs_free_tree_block(trans, root, leaf, 0, 1); + free_extent_buffer(leaf); goto fail; + } + + free_extent_buffer(leaf); + leaf = NULL; key.offset = (u64)-1; new_root = btrfs_read_fs_root_no_name(fs_info, &key); @@ -655,6 +667,7 @@ static int create_snapshot(struct btrfs_root *root, struct inode *dir, struct btrfs_pending_snapshot *pending_snapshot; struct btrfs_trans_handle *trans; int ret; + bool snapshot_force_cow = false; if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state)) return -EINVAL; @@ -671,6 +684,11 @@ static int create_snapshot(struct btrfs_root *root, struct inode *dir, goto free_pending; } + /* + * Force new buffered writes to reserve space even when NOCOW is + * possible. This is to avoid later writeback (running dealloc) to + * fallback to COW mode and unexpectedly fail with ENOSPC. + */ atomic_inc(&root->will_be_snapshotted); smp_mb__after_atomic(); btrfs_wait_for_no_snapshotting_writes(root); @@ -679,6 +697,14 @@ static int create_snapshot(struct btrfs_root *root, struct inode *dir, if (ret) goto dec_and_free; + /* + * All previous writes have started writeback in NOCOW mode, so now + * we force future writes to fallback to COW mode during snapshot + * creation. + */ + atomic_inc(&root->snapshot_force_cow); + snapshot_force_cow = true; + btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1); btrfs_init_block_rsv(&pending_snapshot->block_rsv, @@ -744,6 +770,8 @@ static int create_snapshot(struct btrfs_root *root, struct inode *dir, fail: btrfs_subvolume_release_metadata(fs_info, &pending_snapshot->block_rsv); dec_and_free: + if (snapshot_force_cow) + atomic_dec(&root->snapshot_force_cow); if (atomic_dec_and_test(&root->will_be_snapshotted)) wake_up_atomic_t(&root->will_be_snapshotted); free_pending: @@ -2021,9 +2049,14 @@ static noinline int copy_to_sk(struct btrfs_path *path, sh.len = item_len; sh.transid = found_transid; - /* copy search result header */ - if (copy_to_user(ubuf + *sk_offset, &sh, sizeof(sh))) { - ret = -EFAULT; + /* + * Copy search result header. If we fault then loop again so we + * can fault in the pages and -EFAULT there if there's a + * problem. Otherwise we'll fault and then copy the buffer in + * properly this next time through + */ + if (probe_user_write(ubuf + *sk_offset, &sh, sizeof(sh))) { + ret = 0; goto out; } @@ -2031,10 +2064,14 @@ static noinline int copy_to_sk(struct btrfs_path *path, if (item_len) { char __user *up = ubuf + *sk_offset; - /* copy the item */ - if (read_extent_buffer_to_user(leaf, up, - item_off, item_len)) { - ret = -EFAULT; + /* + * Copy the item, same behavior as above, but reset the + * * sk_offset so we copy the full thing again. + */ + if (read_extent_buffer_to_user_nofault(leaf, up, + item_off, item_len)) { + ret = 0; + *sk_offset -= sizeof(sh); goto out; } @@ -2122,6 +2159,11 @@ static noinline int search_ioctl(struct inode *inode, key.offset = sk->min_offset; while (1) { + ret = fault_in_pages_writeable(ubuf + sk_offset, + *buf_size - sk_offset); + if (ret) + break; + ret = btrfs_search_forward(root, &key, path, sk->min_transid); if (ret != 0) { if (ret > 0) @@ -3833,6 +3875,8 @@ process_slot: ret = -EINTR; goto out; } + + cond_resched(); } ret = 0; |