From d92915c35bfaf763d78bf1d5ac7f183420e3bd99 Mon Sep 17 00:00:00 2001 From: "Ernesto A. Fernández" 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 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 --- fs/hfsplus/extents.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'fs/hfsplus/extents.c') diff --git a/fs/hfsplus/extents.c b/fs/hfsplus/extents.c index 8e0f59767694..8a8893d522ef 100644 --- a/fs/hfsplus/extents.c +++ b/fs/hfsplus/extents.c @@ -100,6 +100,10 @@ static int __hfsplus_ext_write_extent(struct inode *inode, if (hip->extent_state & HFSPLUS_EXT_NEW) { if (res != -ENOENT) return res; + /* Fail early and avoid ENOSPC during the btree operation */ + res = hfs_bmap_reserve(fd->tree, fd->tree->depth + 1); + if (res) + return res; hfs_brec_insert(fd, hip->cached_extents, sizeof(hfsplus_extent_rec)); hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW); -- cgit v1.2.3-59-g8ed1b