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

Darrick J. Wong
2022-08-09T19:07:26Z

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.

> +{
> + 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?

Otherwise looks good here.

--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
>