From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Date: Wed, 18 Jan 2023 10:43:20 +0100 Subject: [Cluster-devel] return an ERR_PTR from __filemap_get_folio Message-ID: <20230118094329.9553-1-hch@lst.de> List-Id: To: cluster-devel.redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Hi all, __filemap_get_folio and its wrappers can return NULL for three different conditions, which in some cases requires the caller to reverse engineer the decision making. This is fixed by returning an ERR_PTR instead of NULL and thus transporting the reason for the failure. But to make that work we first need to ensure that no xa_value special case is returned and thus return the FGP_ENTRY flag. It turns out that flag is barely used and can usually be deal with in a better way. Note that the shmem patches in here are non-trivial and need some careful review and testing. Diffstat fs/afs/dir.c | 10 +++---- fs/afs/dir_edit.c | 2 - fs/afs/write.c | 4 +- fs/btrfs/disk-io.c | 2 - fs/btrfs/extent_io.c | 2 + fs/ext4/inode.c | 2 - fs/ext4/move_extent.c | 8 ++--- fs/gfs2/lops.c | 2 + fs/hugetlbfs/inode.c | 2 - fs/iomap/buffered-io.c | 6 ++-- fs/netfs/buffered_read.c | 4 +- fs/nilfs2/page.c | 6 ++-- include/linux/pagemap.h | 4 +- include/linux/shmem_fs.h | 1 mm/filemap.c | 27 ++++++++----------- mm/folio-compat.c | 4 +- mm/huge_memory.c | 5 +-- mm/memcontrol.c | 2 - mm/mincore.c | 2 - mm/shmem.c | 64 +++++++++++++++++++---------------------------- mm/swap_state.c | 17 ++++++------ mm/swapfile.c | 4 +- mm/truncate.c | 15 +++++------ 23 files changed, 93 insertions(+), 102 deletions(-)