6.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: Zizhi Wo <wozizhi@xxxxxxxxxx>
[ 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@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20241107110649.3980193-3-wozizhi@xxxxxxxxxx
Acked-by: David Howells <dhowells@xxxxxxxxxx>
Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 bdd321017f1c4..38ca6dce8ef29 100644
--- a/fs/cachefiles/ondemand.c
+++ b/fs/cachefiles/ondemand.c
@@ -77,8 +77,10 @@ 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;
}
--
2.43.0
