6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Zizhi Wo wozizhi@huawei.com
[ Upstream commit 56f4856b425a30e1d8b3e41e6cde8bfba90ba5f8 ]
In the erofs on-demand loading scenario, read and write operations are usually delivered through "off" and "len" contained in read req in user mode. Naturally, pwrite is used to specify a specific offset to complete write operations.
However, if the write(not pwrite) syscall is called multiple times in the read-ahead scenario, we need to manually update ki_pos after each write operation to update file->f_pos.
This step is currently missing from the cachefiles_ondemand_fd_write_iter function, added to address this issue.
Fixes: c8383054506c ("cachefiles: notify the user daemon when looking up cookie") Signed-off-by: Zizhi Wo wozizhi@huawei.com Link: https://lore.kernel.org/r/20241107110649.3980193-3-wozizhi@huawei.com Acked-by: David Howells dhowells@redhat.com Signed-off-by: Christian Brauner brauner@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- fs/cachefiles/ondemand.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/fs/cachefiles/ondemand.c b/fs/cachefiles/ondemand.c index 2185e2908dba8..d1a0264b08a6c 100644 --- a/fs/cachefiles/ondemand.c +++ b/fs/cachefiles/ondemand.c @@ -78,8 +78,10 @@ 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) + if (!ret) { ret = len; + kiocb->ki_pos += ret; + }
return ret; }