Re: [PATCH 3/3] ceph: enable/disable dentry complete flags via mount option

[Alex Elder <elder@dreamhost.com>]

On Thu, 2011-12-22 at 12:13 -0800, Sage Weil wrote:
> Enable/disable use of the dentry dir 'complete' flag via a mount option.
> 
> Signed-off-by: Sage Weil <sage@newdream.net>
> ---
>  fs/ceph/dir.c   |    3 ++-
>  fs/ceph/super.c |   14 ++++++++++++++
>  fs/ceph/super.h |    1 +
>  3 files changed, 17 insertions(+), 1 deletions(-)
> 
> diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
> index caddb7d..35db035 100644
> --- a/fs/ceph/dir.c
> +++ b/fs/ceph/dir.c
> @@ -1134,7 +1134,8 @@ void ceph_dir_set_complete(struct inode *inode)
>  {
>  	struct dentry *dentry = d_find_any_alias(inode);
>  	
> -	if (dentry && ceph_dentry(dentry)) {
> +	if (dentry && ceph_dentry(dentry) &&
> +	    ceph_test_mount_opt(ceph_sb_to_client(dentry->d_sb), USEDCACHE)) {
>  		dout(" marking %p (%p) complete\n", inode, dentry);
>  		set_bit(CEPH_D_COMPLETE, &ceph_dentry(dentry)->flags);
>  	}

You should clear the CEPH_D_COMPLETE bit
conditionally in ceph_dir_clear_complete()
also.

And for ceph_dir_test_complete() I think
that whole function should be made conditional
on the mount option too, although I honestly
don't know whether it should return true
or false in the "nousedcache" case.

I realize making the test and clear ones
conditional is not technically necessary,
but I think it's good to handle it all
symmetrically.

Aside from that though I think the change
looks fine.

					-Alex

> diff --git a/fs/ceph/super.c b/fs/ceph/super.c
> index b48f15f..3f4e5ad 100644
> --- a/fs/ceph/super.c
> +++ b/fs/ceph/super.c
> @@ -131,6 +131,8 @@ enum {
>  	Opt_rbytes,
>  	Opt_norbytes,
>  	Opt_noasyncreaddir,
> +	Opt_usedcache,
> +	Opt_nousedcache,
>  	Opt_ino32,
>  };
>  
> @@ -152,6 +154,8 @@ static match_table_t fsopt_tokens = {
>  	{Opt_rbytes, "rbytes"},
>  	{Opt_norbytes, "norbytes"},
>  	{Opt_noasyncreaddir, "noasyncreaddir"},
> +	{Opt_usedcache, "usedcache"},
> +	{Opt_nousedcache, "nousedcache"},
>  	{Opt_ino32, "ino32"},
>  	{-1, NULL}
>  };
> @@ -231,6 +235,12 @@ static int parse_fsopt_token(char *c, void *private)
>  	case Opt_noasyncreaddir:
>  		fsopt->flags |= CEPH_MOUNT_OPT_NOASYNCREADDIR;
>  		break;
> +	case Opt_usedcache:
> +		fsopt->flags |= CEPH_MOUNT_OPT_USEDCACHE;
> +		break;
> +	case Opt_nousedcache:
> +		fsopt->flags &= ~CEPH_MOUNT_OPT_USEDCACHE;
> +		break;
>  	case Opt_ino32:
>  		fsopt->flags |= CEPH_MOUNT_OPT_INO32;
>  		break;
> @@ -377,6 +387,10 @@ static int ceph_show_options(struct seq_file *m, struct vfsmount *mnt)
>  		seq_puts(m, ",norbytes");
>  	if (fsopt->flags & CEPH_MOUNT_OPT_NOASYNCREADDIR)
>  		seq_puts(m, ",noasyncreaddir");
> +	if (fsopt->flags & CEPH_MOUNT_OPT_USEDCACHE)
> +		seq_puts(m, ",usedcache");
> +	else
> +		seq_puts(m, ",nousedcache");
>  
>  	if (fsopt->wsize)
>  		seq_printf(m, ",wsize=%d", fsopt->wsize);
> diff --git a/fs/ceph/super.h b/fs/ceph/super.h
> index edcbf37..9270d9d 100644
> --- a/fs/ceph/super.h
> +++ b/fs/ceph/super.h
> @@ -28,6 +28,7 @@
>  #define CEPH_MOUNT_OPT_RBYTES          (1<<5) /* dir st_bytes = rbytes */
>  #define CEPH_MOUNT_OPT_NOASYNCREADDIR  (1<<7) /* no dcache readdir */
>  #define CEPH_MOUNT_OPT_INO32           (1<<8) /* 32 bit inos */
> +#define CEPH_MOUNT_OPT_USEDCACHE       (1<<9)
>  
>  #define CEPH_MOUNT_OPT_DEFAULT    (CEPH_MOUNT_OPT_RBYTES)
>