hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/ICJHNT -------------------------------- In __cachefiles_write(), if the return value of the write operation > 0, it is set to 0. This makes it impossible to distinguish scenarios where a partial write has occurred, and causes the outer function cachefiles_ondemand_fd_write_iter() to unconditionally return the full length specified by user space. Fix it by modifying "ret" to reflect the actual number of bytes written. Furthermore, returning a value greater than 0 from __cachefiles_write() does not affect other call paths, such as fscache_write_to_cache() and fscache_write(). Fixes: c8383054506c ("cachefiles: notify the user daemon when looking up cookie") Signed-off-by: Zizhi Wo <wozizhi@huawei.com> --- fs/cachefiles/io.c | 2 -- fs/cachefiles/ondemand.c | 4 +--- 2 files changed, 1 insertion(+), 5 deletions(-) diff --git a/fs/cachefiles/io.c b/fs/cachefiles/io.c index f7a507ddd668..2ba98f3861e8 100644 --- a/fs/cachefiles/io.c +++ b/fs/cachefiles/io.c @@ -357,8 +357,6 @@ int __cachefiles_write(struct cachefiles_object *object, default: ki->was_async = false; cachefiles_write_complete(&ki->iocb, ret); - if (ret > 0) - ret = 0; break; } diff --git a/fs/cachefiles/ondemand.c b/fs/cachefiles/ondemand.c index 6a0921f31a8a..8b0d123b51b1 100644 --- a/fs/cachefiles/ondemand.c +++ b/fs/cachefiles/ondemand.c @@ -84,10 +84,8 @@ static ssize_t cachefiles_ondemand_fd_write_iter(struct kiocb *kiocb, trace_cachefiles_ondemand_fd_write(object, file_inode(file), pos, len); ret = __cachefiles_write(object, file, pos, iter, NULL, NULL); - if (!ret) { - ret = len; + if (ret > 0) kiocb->ki_pos += ret; - } out: fput(file); return ret; -- 2.39.2