[GIT PULL] Splice updates for 6.5

From: Jens Axboe
Date: Sun Jun 25 2023 - 22:39:21 EST

Hi Linus,

First batch of splice updates via David, the block side depends on these
and will be going out after this one. In David's words:

This patchset kills off ITER_PIPE to avoid a race between truncate,
iov_iter_revert() on the pipe and an as-yet incomplete DMA to a bio with
unpinned/unref'ed pages from an O_DIRECT splice read. This causes memory
corruption[2]. Instead, we use filemap_splice_read(), which invokes the
buffered file reading code and splices from the pagecache into the pipe;
copy_splice_read(), which bulk-allocates a buffer, reads into it and then
pushes the filled pages into the pipe; or handle it in filesystem-specific
code.

(1) Rename direct_splice_read() to copy_splice_read().

(2) Simplify the calculations for the number of pages to be reclaimed in
copy_splice_read().

(3) Turn do_splice_to() into a helper, vfs_splice_read(), so that it can
be used by overlayfs and coda to perform the checks on the lower fs.

(4) Make vfs_splice_read() jump to copy_splice_read() to handle direct-I/O
and DAX.

(5) Provide shmem with its own splice_read to handle non-existent pages
in the pagecache. We don't want a ->read_folio() as we don't want to
populate holes, but filemap_get_pages() requires it.

(6) Provide overlayfs with its own splice_read to call down to a lower
layer as overlayfs doesn't provide ->read_folio().

(7) Provide coda with its own splice_read to call down to a lower layer as
coda doesn't provide ->read_folio().

(8) Direct ->splice_read to copy_splice_read() in tty, procfs, kernfs
and random files as they just copy to the output buffer and don't
splice pages.

(9) Provide wrappers for afs, ceph, ecryptfs, ext4, f2fs, nfs, ntfs3,
ocfs2, orangefs, xfs and zonefs to do locking and/or revalidation.

(10) Make cifs use filemap_splice_read().

(11) Replace pointers to generic_file_splice_read() with pointers to
filemap_splice_read() as DIO and DAX are handled in the caller;
filesystems can still provide their own alternate ->splice_read() op.

(12) Remove generic_file_splice_read().

(13) Remove ITER_PIPE and its paraphernalia as generic_file_splice_read()
was the only user.

Please pull!


The following changes since commit f1fcbaa18b28dec10281551dfe6ed3a3ed80e3d6:

Linux 6.4-rc2 (2023-05-14 12:51:40 -0700)

are available in the Git repository at:

git://git.kernel.dk/linux.git tags/for-6.5/splice-2023-06-23

for you to fetch changes up to 9eee8bd81421c5e961cbb1a3c3fa1a06fad545e8:

splice: kdoc for filemap_splice_read() and copy_splice_read() (2023-05-24 08:42:17 -0600)

----------------------------------------------------------------
for-6.5/splice-2023-06-23

----------------------------------------------------------------
David Howells (31):
splice: Fix filemap_splice_read() to use the correct inode
splice: Make filemap_splice_read() check s_maxbytes
splice: Rename direct_splice_read() to copy_splice_read()
splice: Clean up copy_splice_read() a bit
splice: Make do_splice_to() generic and export it
splice: Check for zero count in vfs_splice_read()
splice: Make splice from an O_DIRECT fd use copy_splice_read()
splice: Make splice from a DAX file use copy_splice_read()
shmem: Implement splice-read
overlayfs: Implement splice-read
coda: Implement splice-read
tty, proc, kernfs, random: Use copy_splice_read()
net: Make sock_splice_read() use copy_splice_read() by default
9p: Add splice_read wrapper
afs: Provide a splice-read wrapper
ceph: Provide a splice-read wrapper
ecryptfs: Provide a splice-read wrapper
ext4: Provide a splice-read wrapper
f2fs: Provide a splice-read wrapper
nfs: Provide a splice-read wrapper
ntfs3: Provide a splice-read wrapper
ocfs2: Provide a splice-read wrapper
orangefs: Provide a splice-read wrapper
xfs: Provide a splice-read wrapper
zonefs: Provide a splice-read wrapper
trace: Convert trace/seq to use copy_splice_read()
cifs: Use filemap_splice_read()
splice: Use filemap_splice_read() instead of generic_file_splice_read()
splice: Remove generic_file_splice_read()
iov_iter: Kill ITER_PIPE
splice: kdoc for filemap_splice_read() and copy_splice_read()

block/fops.c | 2 +-
drivers/char/random.c | 4 +-
drivers/tty/tty_io.c | 4 +-
fs/9p/vfs_file.c | 26 ++-
fs/adfs/file.c | 2 +-
fs/affs/file.c | 2 +-
fs/afs/file.c | 20 ++-
fs/bfs/file.c | 2 +-
fs/btrfs/file.c | 2 +-
fs/ceph/file.c | 65 +++++++-
fs/cifs/cifsfs.c | 12 +-
fs/cifs/cifsfs.h | 3 -
fs/cifs/file.c | 16 --
fs/coda/file.c | 29 +++-
fs/cramfs/inode.c | 2 +-
fs/ecryptfs/file.c | 27 ++-
fs/erofs/data.c | 2 +-
fs/exfat/file.c | 2 +-
fs/ext2/file.c | 2 +-
fs/ext4/file.c | 13 +-
fs/f2fs/file.c | 43 ++++-
fs/fat/file.c | 2 +-
fs/fuse/file.c | 2 +-
fs/gfs2/file.c | 4 +-
fs/hfs/inode.c | 2 +-
fs/hfsplus/inode.c | 2 +-
fs/hostfs/hostfs_kern.c | 2 +-
fs/hpfs/file.c | 2 +-
fs/jffs2/file.c | 2 +-
fs/jfs/file.c | 2 +-
fs/kernfs/file.c | 2 +-
fs/minix/file.c | 2 +-
fs/nfs/file.c | 23 ++-
fs/nfs/internal.h | 2 +
fs/nfs/nfs4file.c | 2 +-
fs/nilfs2/file.c | 2 +-
fs/ntfs/file.c | 2 +-
fs/ntfs3/file.c | 31 +++-
fs/ocfs2/file.c | 43 ++++-
fs/ocfs2/ocfs2_trace.h | 3 +
fs/omfs/file.c | 2 +-
fs/orangefs/file.c | 22 ++-
fs/overlayfs/file.c | 23 ++-
fs/proc/inode.c | 4 +-
fs/proc/proc_sysctl.c | 2 +-
fs/proc_namespace.c | 6 +-
fs/ramfs/file-mmu.c | 2 +-
fs/ramfs/file-nommu.c | 2 +-
fs/read_write.c | 2 +-
fs/reiserfs/file.c | 2 +-
fs/romfs/mmap-nommu.c | 2 +-
fs/splice.c | 127 +++++++-------
fs/sysv/file.c | 2 +-
fs/ubifs/file.c | 2 +-
fs/udf/file.c | 2 +-
fs/ufs/file.c | 2 +-
fs/vboxsf/file.c | 2 +-
fs/xfs/xfs_file.c | 30 +++-
fs/xfs/xfs_trace.h | 2 +-
fs/zonefs/file.c | 40 ++++-
include/linux/fs.h | 8 +-
include/linux/splice.h | 3 +
include/linux/uio.h | 14 --
kernel/trace/trace.c | 2 +-
lib/iov_iter.c | 431 +-----------------------------------------------
mm/filemap.c | 31 +++-
mm/shmem.c | 134 ++++++++++++++-
net/socket.c | 2 +-
68 files changed, 694 insertions(+), 621 deletions(-)

--
Jens Axboe