svn commit: r193440 - in head/sys: cddl/contrib/opensolaris/uts/common/fs/zfs kern sys

[Kostik Belousov]

On Thu, Jun 04, 2009 at 04:18:08PM +0000, Paul Saab wrote:
> Author: ps
> Date: Thu Jun  4 16:18:07 2009
> New Revision: 193440
> URL: http://svn.freebsd.org/changeset/base/193440
> 
> Log:
>   Support shared vnode locks for write operations when the offset is
>   provided on filesystems that support it.  This really improves mysql
>   + innodb performance on ZFS.
>   
>   Reviewed by:	jhb, kmacy, jeffr
> 
> Modified:
>   head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vfsops.c
>   head/sys/kern/vfs_vnops.c
>   head/sys/sys/mount.h
> 
> Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vfsops.c
> ==============================================================================
> --- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vfsops.c	Thu Jun  4 15:57:38 2009	(r193439)
> +++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vfsops.c	Thu Jun  4 16:18:07 2009	(r193440)
> @@ -573,6 +573,7 @@ zfs_domount(vfs_t *vfsp, char *osname)
>  	vfsp->mnt_flag |= MNT_LOCAL;
>  	vfsp->mnt_kern_flag |= MNTK_MPSAFE;
>  	vfsp->mnt_kern_flag |= MNTK_LOOKUP_SHARED;
> +	vfsp->mnt_kern_flag |= MNTK_SHARED_WRITES;
>  
>  	if (error = dsl_prop_get_integer(osname, "readonly", &readonly, NULL))
>  		goto out;
> 
> Modified: head/sys/kern/vfs_vnops.c
> ==============================================================================
> --- head/sys/kern/vfs_vnops.c	Thu Jun  4 15:57:38 2009	(r193439)
> +++ head/sys/kern/vfs_vnops.c	Thu Jun  4 16:18:07 2009	(r193440)
> @@ -367,7 +367,7 @@ vn_rdwr(rw, vp, base, len, offset, segfl
>  	struct iovec aiov;
>  	struct mount *mp;
>  	struct ucred *cred;
> -	int error;
> +	int error, lock_flags;
>  
>  	VFS_ASSERT_GIANT(vp->v_mount);
>  
> @@ -378,7 +378,13 @@ vn_rdwr(rw, vp, base, len, offset, segfl
>  			    (error = vn_start_write(vp, &mp, V_WAIT | PCATCH))
>  			    != 0)
>  				return (error);
> -			vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
> +			if (mp != NULL &&
> +			    (mp->mnt_kern_flag & MNTK_SHARED_WRITES)) {
> +				lock_flags = LK_SHARED;
> +			} else {
> +				lock_flags = LK_EXCLUSIVE;
> +			}
> +			vn_lock(vp, lock_flags | LK_RETRY);
>  		} else
>  			vn_lock(vp, LK_SHARED | LK_RETRY);
>  
> @@ -564,7 +570,7 @@ vn_write(fp, uio, active_cred, flags, td
>  {
>  	struct vnode *vp;
>  	struct mount *mp;
> -	int error, ioflag;
> +	int error, ioflag, lock_flags;
>  	int vfslocked;
>  
>  	KASSERT(uio->uio_td == td, ("uio_td %p is not td %p",
> @@ -587,7 +593,16 @@ vn_write(fp, uio, active_cred, flags, td
>  	if (vp->v_type != VCHR &&
>  	    (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0)
>  		goto unlock;
> -	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
> + 
> +	if (vp->v_mount != NULL &&
> +	    (vp->v_mount->mnt_kern_flag & MNTK_SHARED_WRITES) &&
> +	    (flags & FOF_OFFSET) != 0) {
> +		lock_flags = LK_SHARED;
> +	} else {
> +		lock_flags = LK_EXCLUSIVE;
> +	}
> +
> +	vn_lock(vp, lock_flags | LK_RETRY);
>  	if ((flags & FOF_OFFSET) == 0)
>  		uio->uio_offset = fp->f_offset;
>  	ioflag |= sequential_heuristic(uio, fp);

Why do you check for vnode v_mount flags in vn_write, while performing
the check on the vop_getwritemount(vp) result for vn_rdwr ?
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 195 bytes
Desc: not available
Url : http://lists.freebsd.org/pipermail/svn-src-head/attachments/20090604/390b494a/attachment.pgp