tree 97f28bb4cecb98694e93b05f862d748c3c8a9096
parent 376270e9ba9c6fbe51a8c9fb6f40ff97aeca3694
author Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com> 1540937177 -0700
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1574962128 +0100

hfs: prevent btree data loss on ENOSPC

[ Upstream commit 54640c7502e5ed41fbf4eedd499e85f9acc9698f ]

Inserting a new 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 or
extents.

Henceforth, check the available disk space before making any changes.
This still leaves the potential problem of corruption on ENOMEM.

There is no need to reserve space before deleting a catalog record, as we
do for hfsplus.  This difference is because hfs index nodes have fixed
length keys.

Link: http://lkml.kernel.org/r/ab5fc8a7d5ffccfd5f27b1cf2cb4ceb6c110da74.1536269131.git.ernesto.mnd.fernandez@gmail.com
Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>