From 376270e9ba9c6fbe51a8c9fb6f40ff97aeca3694 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ernesto=20A=2E=20Fern=C3=A1ndez?= Date: Tue, 30 Oct 2018 15:06:14 -0700 Subject: hfsplus: prevent btree data loss on ENOSPC MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit [ Upstream commit d92915c35bfaf763d78bf1d5ac7f183420e3bd99 ] Inserting or deleting a record in a btree may require splitting several of its nodes. If we hit ENOSPC halfway through, the new nodes will be left orphaned and their records will be lost. This could mean lost inodes, extents or xattrs. Henceforth, check the available disk space before making any changes. This still leaves the potential problem of corruption on ENOMEM. The patch can be tested with xfstests generic/027. Link: http://lkml.kernel.org/r/4596eef22fbda137b4ffa0272d92f0da15364421.1536269129.git.ernesto.mnd.fernandez@gmail.com Signed-off-by: Ernesto A. Fernández Cc: Christoph Hellwig Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- fs/hfsplus/catalog.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) (limited to 'fs/hfsplus/catalog.c') diff --git a/fs/hfsplus/catalog.c b/fs/hfsplus/catalog.c index a5e00f7a4c14..947da72e72a3 100644 --- a/fs/hfsplus/catalog.c +++ b/fs/hfsplus/catalog.c @@ -264,6 +264,14 @@ int hfsplus_create_cat(u32 cnid, struct inode *dir, if (err) return err; + /* + * Fail early and avoid ENOSPC during the btree operations. We may + * have to split the root node at most once. + */ + err = hfs_bmap_reserve(fd.tree, 2 * fd.tree->depth); + if (err) + goto err2; + hfsplus_cat_build_key_with_cnid(sb, fd.search_key, cnid); entry_size = hfsplus_fill_cat_thread(sb, &entry, S_ISDIR(inode->i_mode) ? @@ -332,6 +340,14 @@ int hfsplus_delete_cat(u32 cnid, struct inode *dir, const struct qstr *str) if (err) return err; + /* + * Fail early and avoid ENOSPC during the btree operations. We may + * have to split the root node at most once. + */ + err = hfs_bmap_reserve(fd.tree, 2 * (int)fd.tree->depth - 2); + if (err) + goto out; + if (!str) { int len; @@ -432,6 +448,14 @@ int hfsplus_rename_cat(u32 cnid, return err; dst_fd = src_fd; + /* + * Fail early and avoid ENOSPC during the btree operations. We may + * have to split the root node at most twice. + */ + err = hfs_bmap_reserve(src_fd.tree, 4 * (int)src_fd.tree->depth - 1); + if (err) + goto out; + /* find the old dir entry and read the data */ err = hfsplus_cat_build_key(sb, src_fd.search_key, src_dir->i_ino, src_name); -- cgit v1.2.3