Re: [PATCH RESEND v2 14/18] xfs: remove parent pointers in unlink

Alli
2022-08-10T03:09:48Z

On Tue, 2022-08-09 at 11:45 -0700, Darrick J. Wong wrote:
> On Thu, Aug 04, 2022 at 12:40:09PM -0700, Allison Henderson wrote:
> > This patch removes the parent pointer attribute during unlink
> >
> > [bfoster: rebase, use VFS inode generation]
> > [achender: rebased, changed __unint32_t to xfs_dir2_dataptr_t
> > implemented xfs_attr_remove_parent]
> >
> > Signed-off-by: Dave Chinner <dchinner@redhat.com>
> > Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
> > ---
> > fs/xfs/libxfs/xfs_attr.c | 2 +-
> > fs/xfs/libxfs/xfs_attr.h | 1 +
> > fs/xfs/libxfs/xfs_parent.c | 15 +++++++++++++++
> > fs/xfs/libxfs/xfs_parent.h | 3 +++
> > fs/xfs/xfs_inode.c | 29 +++++++++++++++++++++++------
> > 5 files changed, 43 insertions(+), 7 deletions(-)
> >
> > diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
> > index 0a458ea7051f..77513ff7e1ec 100644
> > --- a/fs/xfs/libxfs/xfs_attr.c
> > +++ b/fs/xfs/libxfs/xfs_attr.c
> > @@ -936,7 +936,7 @@ xfs_attr_defer_replace(
> > }
> >
> > /* Removes an attribute for an inode as a deferred operation */
> > -static int
> > +int
> > xfs_attr_defer_remove(
> > struct xfs_da_args *args)
> > {
> > diff --git a/fs/xfs/libxfs/xfs_attr.h b/fs/xfs/libxfs/xfs_attr.h
> > index b47417b5172f..2e11e5e83941 100644
> > --- a/fs/xfs/libxfs/xfs_attr.h
> > +++ b/fs/xfs/libxfs/xfs_attr.h
> > @@ -545,6 +545,7 @@ bool xfs_attr_is_leaf(struct xfs_inode *ip);
> > int xfs_attr_get_ilocked(struct xfs_da_args *args);
> > int xfs_attr_get(struct xfs_da_args *args);
> > int xfs_attr_defer_add(struct xfs_da_args *args);
> > +int xfs_attr_defer_remove(struct xfs_da_args *args);
> > int xfs_attr_set(struct xfs_da_args *args);
> > int xfs_attr_set_iter(struct xfs_attr_intent *attr);
> > int xfs_attr_remove_iter(struct xfs_attr_intent *attr);
> > diff --git a/fs/xfs/libxfs/xfs_parent.c
> > b/fs/xfs/libxfs/xfs_parent.c
> > index 4ab531c77d7d..03f03f731d02 100644
> > --- a/fs/xfs/libxfs/xfs_parent.c
> > +++ b/fs/xfs/libxfs/xfs_parent.c
> > @@ -123,6 +123,21 @@ xfs_parent_defer_add(
> > return xfs_attr_defer_add(args);
> > }
> >
> > +int
> > +xfs_parent_defer_remove(
> > + struct xfs_trans *tp,
> > + struct xfs_inode *ip,
> > + struct xfs_parent_defer *parent,
> > + xfs_dir2_dataptr_t diroffset)
>
> Same suggestion about setting args->dp here instead of in
> xfs_parent_init.
Sure, that should be fine.

>
> > +{
> > + struct xfs_da_args *args = &parent->args;
> > +
> > + xfs_init_parent_name_rec(&parent->rec, ip, diroffset);
> > + args->trans = tp;
> > + args->hashval = xfs_da_hashname(args->name, args->namelen);
> > + return xfs_attr_defer_remove(args);
> > +}
> > +
> > void
> > xfs_parent_cancel(
> > xfs_mount_t *mp,
> > diff --git a/fs/xfs/libxfs/xfs_parent.h
> > b/fs/xfs/libxfs/xfs_parent.h
> > index 21a350b97ed5..67948f4b3834 100644
> > --- a/fs/xfs/libxfs/xfs_parent.h
> > +++ b/fs/xfs/libxfs/xfs_parent.h
> > @@ -29,6 +29,9 @@ int xfs_parent_init(xfs_mount_t *mp, xfs_inode_t
> > *ip,
> > int xfs_parent_defer_add(struct xfs_trans *tp, struct xfs_inode
> > *ip,
> > struct xfs_parent_defer *parent,
> > xfs_dir2_dataptr_t diroffset);
> > +int xfs_parent_defer_remove(struct xfs_trans *tp, struct xfs_inode
> > *ip,
> > + struct xfs_parent_defer *parent,
> > + xfs_dir2_dataptr_t diroffset);
> > void xfs_parent_cancel(xfs_mount_t *mp, struct xfs_parent_defer
> > *parent);
> >
> > #endif /* __XFS_PARENT_H__ */
> > diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
> > index 6e5deb0d42c4..69bb67f2a252 100644
> > --- a/fs/xfs/xfs_inode.c
> > +++ b/fs/xfs/xfs_inode.c
> > @@ -2464,16 +2464,18 @@ xfs_iunpin_wait(
> > */
> > int
> > xfs_remove(
> > - xfs_inode_t *dp,
> > + struct xfs_inode *dp,
> > struct xfs_name *name,
> > - xfs_inode_t *ip)
> > + struct xfs_inode *ip)
> > {
> > - xfs_mount_t *mp = dp->i_mount;
> > - xfs_trans_t *tp = NULL;
> > + struct xfs_mount *mp = dp->i_mount;
> > + struct xfs_trans *tp = NULL;
> > int is_dir = S_ISDIR(VFS_I(ip)->i_mode);
> > int dontcare;
> > int error = 0;
> > uint resblks;
> > + xfs_dir2_dataptr_t dir_offset;
> > + struct xfs_parent_defer *parent = NULL;
> >
> > trace_xfs_remove(dp, name);
> >
> > @@ -2488,6 +2490,12 @@ xfs_remove(
> > if (error)
> > goto std_return;
> >
> > + if (xfs_has_parent(mp)) {
> > + error = xfs_parent_init(mp, ip, NULL, &parent);
> > + if (error)
> > + goto std_return;
> > + }
> > +
> > /*
> > * We try to get the real space reservation first, allowing for
> > * directory btree deletion(s) implying possible bmap
> > insert(s). If we
> > @@ -2504,7 +2512,7 @@ xfs_remove(
> > &tp, &dontcare);
> > if (error) {
> > ASSERT(error != -ENOSPC);
> > - goto std_return;
> > + goto drop_incompat;
> > }
> >
> > /*
> > @@ -2558,12 +2566,18 @@ xfs_remove(
> > if (error)
> > goto out_trans_cancel;
> >
> > - error = xfs_dir_removename(tp, dp, name, ip->i_ino, resblks,
> > NULL);
> > + error = xfs_dir_removename(tp, dp, name, ip->i_ino, resblks,
> > &dir_offset);
> > if (error) {
> > ASSERT(error != -ENOENT);
> > goto out_trans_cancel;
> > }
> >
> > + if (xfs_has_parent(mp)) {
> > + error = xfs_parent_defer_remove(tp, dp, parent,
> > dir_offset);
>
> If it's safe to gate xfs_parent_cancel on "if (parent)" then can we
> avoid the atomic bit access by doing that here too?
Oh, sure, I likely just forgot to update that conditional.

>
> Otherwise looks good here.
Thank you!

Allison

>
> --D
>
> > + if (error)
> > + goto out_trans_cancel;
> > + }
> > +
> > /*
> > * If this is a synchronous mount, make sure that the
> > * remove transaction goes to disk before returning to
> > @@ -2588,6 +2602,9 @@ xfs_remove(
> > out_unlock:
> > xfs_iunlock(ip, XFS_ILOCK_EXCL);
> > xfs_iunlock(dp, XFS_ILOCK_EXCL);
> > + drop_incompat:
> > + if (parent)
> > + xfs_parent_cancel(mp, parent);
> > std_return:
> > return error;
> > }
> > --
> > 2.25.1
> >