[PATCH 11/22] staging: lustre: mdt: fail FMODE_WRITE open if the client is read only

From: James Simmons
Date: Fri Dec 02 2016 - 19:57:27 EST


From: Li Dongyang <dongyang.li@xxxxxxxxxx>

O_WRONLY/O_RDWR open on a file will get EROFS on a read only client,
but the rpc gets sent to the mdt anyway.
mdt will increase the mot_write_count of the mdt object, blocking
subsequent FMODE_EXEC open to the same file.

This patch makes sure we fail the FMODE_WRITE open with EROFS on the
client straight away without sending the rpc to mdt.

Signed-off-by: Li Dongyang <dongyang.li@xxxxxxxxxx>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-7727
Reviewed-on: http://review.whamcloud.com/18242
Reviewed-by: Ian Costello <icostello@xxxxxxx>
Reviewed-by: Nathaniel Clark <nathaniel.l.clark@xxxxxxxxx>
Reviewed-by: Yang Sheng <yang.sheng@xxxxxxxxx>
Reviewed-by: Oleg Drokin <oleg.drokin@xxxxxxxxx>
Signed-off-by: James Simmons <jsimmons@xxxxxxxxxxxxx>
---
drivers/staging/lustre/lustre/llite/namei.c | 4 ++++
1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/drivers/staging/lustre/lustre/llite/namei.c b/drivers/staging/lustre/lustre/llite/namei.c
index b07079c..9426759 100644
--- a/drivers/staging/lustre/lustre/llite/namei.c
+++ b/drivers/staging/lustre/lustre/llite/namei.c
@@ -572,6 +572,10 @@ static int ll_lookup_it_finish(struct ptlrpc_request *request,
}
}

+ if (it->it_op & IT_OPEN && it->it_flags & FMODE_WRITE &&
+ dentry->d_sb->s_flags & MS_RDONLY)
+ return ERR_PTR(-EROFS);
+
if (it->it_op & IT_CREAT)
opc = LUSTRE_OPC_CREATE;
else
--
1.7.1