Regarding "backupuid" option for linux cifs mounts.

[Hemanth Thummala]

Thanks Steve for the response.
Sure. We will try with latest kernel. Do you know which kernel version has these fixes?

Looking at the captures, "backup intent" is not set for even file opens. For example, I did "cat <filename>" on the mount. I see the desired access is (read|read attrib| Generic read) but without backup intent. Wondering if the mount is ignoring the "backupuid" option. 

Thanks,
Hemanth.
On 12/14/18, 3:40 PM, "Steve French" <smfrench at gmail.com> wrote:

    Can you try running this with more current kernel?  Looks like there
    were 5 "backup intent" related fixes/enhancements added to cifs.ko
    since 4.9 kernel (although at least two are for compounding which is
    not being used in the older 4.9 kernel).  A key one that was missing
    was on directory opens.
    On Fri, Dec 14, 2018 at 5:30 PM Hemanth Thummala
    <hemanth.thummala at nutanix.com> wrote:
    >
    > Hi,
    >
    >
    >
    > We are planning to linux SMB mounts for accessing Samba shares for doing metadata scan for backup purpose. We found the mount options like “backupuid” and ”backupgid” which should ideally set the “backup intent” flag in each create request on this mount point. We have tried using the uid(Autorid ID). Mount was successful. However, we are still NOT seeing the “backup intent” flag.
    >
    >
    >
    > Spent some time looking at the client module source. Looks like it is trying to match the backupuid with the user cred. But, not sure how this cred is supplied. Our client is not part of the domain. Not sure if this step is mandatory.
    >
    >
    >
    > Here are the mount options that we are using:
    >
    > sudo mount -v -t cifs \\\\<IP>\\sh1 -o username=bkp_user,password=******,domain=test_domain.com,vers=3.0,backupuid=<autorid-id> /mnt/test
    >
    >
    >
    > Here is the link that we have followed for documented options:
    >
    > https://urldefense.proofpoint.com/v2/url?u=https-3A__www.systutorials.com_docs_linux_man_8-2Dmount.cifs_&d=DwIFaQ&c=s883GpUCOChKOHiocYtGcg&r=upHhZKvLG1wGJVQsvdamubutehC8co9bx_lsVXPKCKw&m=uzYM0dHNNWUr6g_PrN8ikppGBt_0z_ne3Vvjyj5c884&s=1rX6d5uuTqeECkTlACXGLYBpnzfKNw2pBgwtTVKhNJw&e=
    >
    >
    >
    > We are using centos 7.5 with 4.9 kernel version.
    >
    >
    >
    > Please let us know if you have any suggestions.
    >
    >
    >
    > Thanks,
    >
    > Hemanth.
    >
    >
    >
    >
    
    
    
    -- 
    Thanks,
    
    Steve