Date: Wed, 15 Sep 2010 11:05:42 +0000 (UTC) From: Andriy Gapon <avg@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r212657 - in head/sys/cddl: compat/opensolaris/sys contrib/opensolaris/uts/common/fs/zfs Message-ID: <201009151105.o8FB5ggc034485@svn.freebsd.org>
next in thread | raw e-mail | index | archive | help
Author: avg Date: Wed Sep 15 11:05:41 2010 New Revision: 212657 URL: http://svn.freebsd.org/changeset/base/212657 Log: zfs vn_has_cached_data: take into account v_object->cache != NULL This mirrors code in tmpfs. This changge shouldn't affect much read path, it may cause unnecessary vm_page_lookup calls in the case where v_object has no active or inactive pages but has some cache pages. I believe this situation to be non-essential. In write path this change should allow us to properly detect the above case and free a cache page when we write to a range that corresponds to it. If this situation is undetected then we could have a discrepancy between data in page cache and in ARC or on disk. This change allows us to re-enable vn_has_cached_data() check in zfs_write. NOTE: strictly speaking resident_page_count and cache fields of v_object should be exmined under VM_OBJECT_LOCK, but for this particular usage we may get away with it. Discussed with: alc, kib Approved by: pjd Tested with: tools/regression/fsx MFC after: 3 weeks Modified: head/sys/cddl/compat/opensolaris/sys/vnode.h head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c Modified: head/sys/cddl/compat/opensolaris/sys/vnode.h ============================================================================== --- head/sys/cddl/compat/opensolaris/sys/vnode.h Wed Sep 15 11:04:02 2010 (r212656) +++ head/sys/cddl/compat/opensolaris/sys/vnode.h Wed Sep 15 11:05:41 2010 (r212657) @@ -69,7 +69,9 @@ vn_is_readonly(vnode_t *vp) #define vn_vfsunlock(vp) do { } while (0) #define vn_ismntpt(vp) ((vp)->v_type == VDIR && (vp)->v_mountedhere != NULL) #define vn_mountedvfs(vp) ((vp)->v_mountedhere) -#define vn_has_cached_data(vp) ((vp)->v_object != NULL && (vp)->v_object->resident_page_count > 0) +#define vn_has_cached_data(vp) \ + ((vp)->v_object != NULL && ((vp)->v_object->resident_page_count > 0 \ + || (vp)->v_object->cache != NULL)) #define vn_exists(vp) do { } while (0) #define vn_invalid(vp) do { } while (0) #define vn_renamepath(tdvp, svp, tnm, lentnm) do { } while (0) Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c ============================================================================== --- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c Wed Sep 15 11:04:02 2010 (r212656) +++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c Wed Sep 15 11:05:41 2010 (r212657) @@ -933,17 +933,7 @@ again: uioskip(uio, tx_bytes); } - /* - * XXXPJD: There are some cases (triggered by fsx) where - * vn_has_cached_data(vp) returns false when it should - * return true. This should be investigated. - */ -#if 0 - if (tx_bytes && vn_has_cached_data(vp)) -#else - if (tx_bytes && vp->v_object != NULL) -#endif - { + if (tx_bytes && vn_has_cached_data(vp)) { update_pages(vp, woff, tx_bytes, zfsvfs->z_os, zp->z_id, uio->uio_segflg, tx); }
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201009151105.o8FB5ggc034485>