From fdd4e15838e59c394a1ec4963b57c22c12608685 Mon Sep 17 00:00:00 2001 From: "Yan, Zheng" Date: Tue, 16 Jun 2015 20:48:56 +0800 Subject: ceph: rework dcache readdir Previously our dcache readdir code relies on that child dentries in directory dentry's d_subdir list are sorted by dentry's offset in descending order. When adding dentries to the dcache, if a dentry already exists, our readdir code moves it to head of directory dentry's d_subdir list. This design relies on dcache internals. Al Viro suggests using ncpfs's approach: keeping array of pointers to dentries in page cache of directory inode. the validity of those pointers are presented by directory inode's complete and ordered flags. When a dentry gets pruned, we clear directory inode's complete flag in the d_prune() callback. Before moving a dentry to other directory, we clear the ordered flag for both old and new directory. Signed-off-by: Yan, Zheng --- fs/ceph/caps.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) (limited to 'fs/ceph/caps.c') diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c index dd7b20adf1d4..dc10c9dd36c1 100644 --- a/fs/ceph/caps.c +++ b/fs/ceph/caps.c @@ -833,7 +833,9 @@ int __ceph_caps_used(struct ceph_inode_info *ci) used |= CEPH_CAP_PIN; if (ci->i_rd_ref) used |= CEPH_CAP_FILE_RD; - if (ci->i_rdcache_ref || ci->vfs_inode.i_data.nrpages) + if (ci->i_rdcache_ref || + (!S_ISDIR(ci->vfs_inode.i_mode) && /* ignore readdir cache */ + ci->vfs_inode.i_data.nrpages)) used |= CEPH_CAP_FILE_CACHE; if (ci->i_wr_ref) used |= CEPH_CAP_FILE_WR; @@ -1651,9 +1653,10 @@ retry_locked: * If we fail, it's because pages are locked.... try again later. */ if ((!is_delayed || mdsc->stopping) && - ci->i_wrbuffer_ref == 0 && /* no dirty pages... */ - inode->i_data.nrpages && /* have cached pages */ - (file_wanted == 0 || /* no open files */ + !S_ISDIR(inode->i_mode) && /* ignore readdir cache */ + ci->i_wrbuffer_ref == 0 && /* no dirty pages... */ + inode->i_data.nrpages && /* have cached pages */ + (file_wanted == 0 || /* no open files */ (revoking & (CEPH_CAP_FILE_CACHE| CEPH_CAP_FILE_LAZYIO))) && /* or revoking cache */ !tried_invalidate) { @@ -2805,7 +2808,8 @@ static void handle_cap_grant(struct ceph_mds_client *mdsc, * try to invalidate (once). (If there are dirty buffers, we * will invalidate _after_ writeback.) */ - if (((cap->issued & ~newcaps) & CEPH_CAP_FILE_CACHE) && + if (!S_ISDIR(inode->i_mode) && /* don't invalidate readdir cache */ + ((cap->issued & ~newcaps) & CEPH_CAP_FILE_CACHE) && (newcaps & CEPH_CAP_FILE_LAZYIO) == 0 && !ci->i_wrbuffer_ref) { if (try_nonblocking_invalidate(inode)) { -- cgit v1.2.3