From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Mon, 2 Apr 2018 16:11:49 -0400 From: Vivek Goyal Subject: Re: [PATCH v13 12/28] ovl: Fix ovl_getattr() to get number of blocks from lower Message-ID: <20180402201149.GH23306@redhat.com> References: <20180329193854.13814-1-vgoyal@redhat.com> <20180329193854.13814-13-vgoyal@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: To: Amir Goldstein Cc: overlayfs , Miklos Szeredi List-ID: On Fri, Mar 30, 2018 at 12:24:15PM +0300, Amir Goldstein wrote: > On Thu, Mar 29, 2018 at 10:38 PM, Vivek Goyal wrote: > > If an inode has been copied up metadata only, then we need to query the > > number of blocks from lower and fill up the stat->st_blocks. > > > > We need to be careful about races where we are doing stat on one cpu and > > data copy up is taking place on other cpu. We want to return > > stat->st_blocks either from lower or stable upper and not something in > > between. Hence, ovl_has_upperdata() is called first to figure out whether > > block reporting will take place from lower or upper. > > > > Reviewed-by: Amir Goldstein > > Signed-off-by: Vivek Goyal > > --- > > fs/overlayfs/inode.c | 17 ++++++++++++++++- > > fs/overlayfs/overlayfs.h | 1 + > > fs/overlayfs/util.c | 16 ++++++++++++++++ > > 3 files changed, 33 insertions(+), 1 deletion(-) > > > > diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c > > index e1dbfed0c449..cd03f3e642fd 100644 > > --- a/fs/overlayfs/inode.c > > +++ b/fs/overlayfs/inode.c > > @@ -76,6 +76,9 @@ int ovl_getattr(const struct path *path, struct kstat *stat, > > bool is_dir = S_ISDIR(dentry->d_inode->i_mode); > > bool samefs = ovl_same_sb(dentry->d_sb); > > int err; > > + bool metacopy = false; > > + > > + metacopy = ovl_is_metacopy_dentry(dentry); > > > > type = ovl_path_real(dentry, &realpath); > > old_cred = ovl_override_creds(dentry->d_sb); > > @@ -93,7 +96,8 @@ int ovl_getattr(const struct path *path, struct kstat *stat, > > if (!is_dir || samefs) { > > if (OVL_TYPE_ORIGIN(type)) { > > struct kstat lowerstat; > > - u32 lowermask = STATX_INO | (!is_dir ? STATX_NLINK : 0); > > + u32 lowermask = STATX_INO | STATX_BLOCKS | > > + (!is_dir ? STATX_NLINK : 0); > > Leftover. > > But I think you could do with one vfs_getattr(): > > if (!is_dir || samefs) { > u32 lowermask = metacopy ? STATX_BLOCKS : 0; > if (OVL_TYPE_ORIGIN(type)) > lowermask |= STATX_INO | (!is_dir ? STATX_NLINK : 0); > if (lowermask) { > ovl_path_lower(dentry, &realpath); > err = vfs_getattr(&realpath, &lowerstat, We now support mid layer metacopy dentries. So we will need to do vfs_getattr() on lowest data dentry for data blocks. While rest of the info (inode number and nlink) comes from top most lower dentry. So I don't think we can get rid of extra vfs_getattr()? Vivek