[LU-3557] open(2) an existing file with O_RDONLY|O_CREAT fails with -EROFS, ro mounted client

• Status: Resolved
• Project: Lustre
• Affects Version/s: Lustre 2.4.0
• Fix Version/s: Lustre 2.5.0
• Type: Bug
• Priority: Minor
• Reporter: Li Dongyang (Inactive)
• Assignee: Emoly Liu
• Resolution: Fixed
• Labels: patch
• Severity: 3

Description

Currently with a read only mount, open(2) with O_RDONLY|O_CREAT will fail with -EROFS, no matter the file exists or not.
If the file is already there and we don't need to create the file, we should make the open work.
The gcc-fortran runtime tends to add O_CREAT flag when it's trying to open a file, this prevents us from using the fortran based apps.

Comments

[Li Dongyang (Inactive)]

patch for master http://review.whamcloud.com/6893

[Jodi Levi (Inactive)]

Emoly,
Could you have a look at this one?
Thank you!

[Li Xi (Inactive)]

FYI, when opening a existed file on readonly ext3 file system, we will get following results.

open(existed_file, O_RDWR | O_CREAT) -> -EROFS
open(existed_file, O_CREAT) -> 0
open(existed_file, O_WRONLY | O_CREAT) -> -EROFS
open(existed_file, O_RDONLY | O_CREAT) -> 0

Obviously, opening a non-exist file will return EROFS no matter what the flag is.

[Emoly Liu]

patch landed for 2.5

[Shuichi Ihara (Inactive)]

backport patches http://review.whamcloud.com/#/c/7550/ for b2_1