fs: 9p: add generic splice_read file operations (cf03f316) · Commits · 戴 / test

The v9fs file operations were missing the splice_read operations, which breaks sendfile() of files on such a filesystem. I discovered this while trying to load an eBPF program using iproute2 inside a 'virtme' environment which uses 9pfs for the virtual file system. iproute2 relies on sendfile() with an AF_ALG socket to hash files, which was erroring out in the virtual environment. Since generic_file_splice_read() seems to just implement splice_read in terms of the read_iter operation, I simply added the generic implementation to the file operations, which fixed the error I was seeing. A quick grep indicates that this is what most other file systems do as well. Link: http://lkml.kernel.org/r/20201201135409.55510-1-toke@redhat.com Fixes: ("fs: don't allow splice read/write without explicit ops") Signed-off-by:

Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by:

Dominique Martinet <asmadeus@codewreck.org>

fs/9p/vfs_file.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -655,6 +655,7 @@ const struct file_operations v9fs_cached_file_operations = {
		.release = v9fs_dir_release,
		.lock = v9fs_file_lock,
		.mmap = v9fs_file_mmap,
		.splice_read = generic_file_splice_read,
		.fsync = v9fs_file_fsync,
		};

		@@ -667,6 +668,7 @@ const struct file_operations v9fs_cached_file_operations_dotl = {
		.lock = v9fs_file_lock_dotl,
		.flock = v9fs_file_flock_dotl,
		.mmap = v9fs_file_mmap,
		.splice_read = generic_file_splice_read,
		.fsync = v9fs_file_fsync_dotl,
		};

		@@ -678,6 +680,7 @@ const struct file_operations v9fs_file_operations = {
		.release = v9fs_dir_release,
		.lock = v9fs_file_lock,
		.mmap = generic_file_readonly_mmap,
		.splice_read = generic_file_splice_read,
		.fsync = v9fs_file_fsync,
		};

		@@ -690,6 +693,7 @@ const struct file_operations v9fs_file_operations_dotl = {
		.lock = v9fs_file_lock_dotl,
		.flock = v9fs_file_flock_dotl,
		.mmap = generic_file_readonly_mmap,
		.splice_read = generic_file_splice_read,
		.fsync = v9fs_file_fsync_dotl,
		};

		@@ -701,6 +705,7 @@ const struct file_operations v9fs_mmap_file_operations = {
		.release = v9fs_dir_release,
		.lock = v9fs_file_lock,
		.mmap = v9fs_mmap_file_mmap,
		.splice_read = generic_file_splice_read,
		.fsync = v9fs_file_fsync,
		};

		@@ -713,5 +718,6 @@ const struct file_operations v9fs_mmap_file_operations_dotl = {
		.lock = v9fs_file_lock_dotl,
		.flock = v9fs_file_flock_dotl,
		.mmap = v9fs_mmap_file_mmap,
		.splice_read = generic_file_splice_read,
		.fsync = v9fs_file_fsync_dotl,
		};

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