[PATCH v4 2/3] splice: fsnotify_access(fd)/fsnotify_modify(fd) in vmsplice

From: Ahelenia Ziemiańska
Date: Tue Jun 27 2023 - 16:51:15 EST


Same logic applies here: this can fill up the pipe and pollers that rely
on getting IN_MODIFY notifications never wake up.

Fixes: 983652c69199 ("splice: report related fsnotify events")
Link: https://lore.kernel.org/linux-fsdevel/jbyihkyk5dtaohdwjyivambb2gffyjs3dodpofafnkkunxq7bu@jngkdxx65pux/t/#u
Link: https://bugs.debian.org/1039488
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Amir Goldstein <amir73il@xxxxxxxxx>
---
fs/splice.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/fs/splice.c b/fs/splice.c
index b5c7a5ae0e94..d3a7f4d5c078 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -1341,6 +1341,9 @@ static long vmsplice_to_user(struct file *file, struct iov_iter *iter,
pipe_unlock(pipe);
}

+ if (ret > 0)
+ fsnotify_access(file);
+
return ret;
}

@@ -1370,8 +1373,10 @@ static long vmsplice_to_pipe(struct file *file, struct iov_iter *iter,
if (!ret)
ret = iter_to_pipe(iter, pipe, buf_flag);
pipe_unlock(pipe);
- if (ret > 0)
+ if (ret > 0) {
wakeup_pipe_readers(pipe);
+ fsnotify_modify(file);
+ }
return ret;
}

--
2.39.2

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