From 14e3e989f6a5d9646b6cf60690499cc8bdc11f7d Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 27 Dec 2020 10:56:33 -0800 Subject: [PATCH] proc mountinfo: make splice available again MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Since commit 36e2c7421f02 ("fs: don't allow splice read/write without explicit ops") we've required that file operation structures explicitly enable splice support, rather than falling back to the default handlers. Most /proc files use the indirect 'struct proc_ops' to describe their file operations, and were fixed up to support splice earlier in commits 40be821d627c..b24c30c67863, but the mountinfo files interact with the VFS directly using their own 'struct file_operations' and got missed as a result. This adds the necessary support for splice to work for /proc/*/mountinfo and friends. Reported-by: Joan Bruguera Micó Reported-by: Jussi Kivilinna Link: https://bugzilla.kernel.org/show_bug.cgi?id=209971 Cc: Greg Kroah-Hartman Cc: Christoph Hellwig Signed-off-by: Linus Torvalds --- fs/proc_namespace.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/fs/proc_namespace.c b/fs/proc_namespace.c index e59d4bb3a89e..eafb75755fa3 100644 --- a/fs/proc_namespace.c +++ b/fs/proc_namespace.c @@ -320,7 +320,8 @@ static int mountstats_open(struct inode *inode, struct file *file) const struct file_operations proc_mounts_operations = { .open = mounts_open, - .read = seq_read, + .read_iter = seq_read_iter, + .splice_read = generic_file_splice_read, .llseek = seq_lseek, .release = mounts_release, .poll = mounts_poll, @@ -328,7 +329,8 @@ const struct file_operations proc_mounts_operations = { const struct file_operations proc_mountinfo_operations = { .open = mountinfo_open, - .read = seq_read, + .read_iter = seq_read_iter, + .splice_read = generic_file_splice_read, .llseek = seq_lseek, .release = mounts_release, .poll = mounts_poll, @@ -336,7 +338,8 @@ const struct file_operations proc_mountinfo_operations = { const struct file_operations proc_mountstats_operations = { .open = mountstats_open, - .read = seq_read, + .read_iter = seq_read_iter, + .splice_read = generic_file_splice_read, .llseek = seq_lseek, .release = mounts_release, };