Re: [PATCH] mount.nfs - hide EBUSY errors.

[Steve Dickson <SteveD@redhat.com>]

On 02/17/2016 09:59 PM, NeilBrown wrote:
> 
> Linux only returns EBUSY for a non-remount mount if the exact
> requested filesystem is already mounted.  Arguably this is not an
> error.
> 
> "mount -a" tries to see if each requested filesystem is already mounted.
> Sometimes it gets it wrong - e.g. hostname aliases can confuse it.
> So "mount -a" will report a failure "already mounted", which is
> wrong because it should filter those out.
> 
> An easy fix it just to be silent about EBUSY.  As the requested
> result (a given filesystem being mounted at a given location) is in
> effect after the EBUSY return, we can just treat it as success.
> 
> This removes the confusing "already mounted" errors.
> 
> Signed-off-by: NeilBrown <neilb@suse.com>
Committed... 

steved.

> ---
>  utils/mount/stropts.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/utils/mount/stropts.c b/utils/mount/stropts.c
> index 86829a902bfd..320dde2fab92 100644
> --- a/utils/mount/stropts.c
> +++ b/utils/mount/stropts.c
> @@ -960,6 +960,15 @@ static int nfsmount_fg(struct nfsmount_info *mi)
>  		if (nfs_try_mount(mi))
>  			return EX_SUCCESS;
>  
> +		if (errno == EBUSY)
> +			/* The only cause of EBUSY is if exactly the desired
> +			 * filesystem is already mounted.  That can arguably
> +			 * be seen as success.  "mount -a" tries to optimise
> +			 * out this case but sometimes fails.  Help it out
> +			 * by pretending everything is rosy
> +			 */
> +			return EX_SUCCESS;
> +
>  		if (nfs_is_permanent_error(errno))
>  			break;
>  
>