On Wed, Jul 06, 2022 at 08:43:19AM +1000, Dave Chinner wrote:
> On Tue, Jul 05, 2022 at 03:09:51PM -0700, Darrick J. Wong wrote:
> > From: Darrick J. Wong <djwong@xxxxxxxxxx>
> >
> > Modify xfs_ifork_ptr to return a NULL pointer if the caller asks for the
> > attribute fork but i_forkoff is zero. This eliminates the ambiguity
> > between i_forkoff and i_af.if_present, which should make it easier to
> > understand the lifetime of attr forks.
> >
> > While we're at it, remove the if_present checks around calls to
> > xfs_idestroy_fork and xfs_ifork_zap_attr since they can both handle attr
> > forks that have already been torn down.
> >
> > Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
> > ---
> > fs/xfs/libxfs/xfs_attr.c | 2 --
> > fs/xfs/libxfs/xfs_attr.h | 2 +-
> > fs/xfs/libxfs/xfs_bmap.c | 1 -
> > fs/xfs/libxfs/xfs_inode_buf.c | 1 -
> > fs/xfs/libxfs/xfs_inode_fork.c | 7 +------
> > fs/xfs/libxfs/xfs_inode_fork.h | 1 -
> > fs/xfs/xfs_attr_inactive.c | 11 ++++-------
> > fs/xfs/xfs_attr_list.c | 1 -
> > fs/xfs/xfs_icache.c | 8 +++-----
> > fs/xfs/xfs_inode.c | 5 ++---
> > fs/xfs/xfs_inode.h | 2 +-
> > 11 files changed, 12 insertions(+), 29 deletions(-)
> >
> >
> > diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
> > index 6b0d744e5947..002d7dea2190 100644
> > --- a/fs/xfs/libxfs/xfs_attr.c
> > +++ b/fs/xfs/libxfs/xfs_attr.c
> > @@ -69,8 +69,6 @@ xfs_inode_hasattr(
> > {
> > if (!XFS_IFORK_Q(ip))
> > return 0;
> > - if (!ip->i_af.if_present)
> > - return 0;
>
> I much prefer the "if (attr fork present)" style over the
> XFS_IFORK_Q() macro. I always have to go look up what all the whacky
> IFORK/DFORK macros actually mean, so if we are changing all this
> code can we wrap this in something like:
>
> static inline bool
> xfs_inode_has_attr_fork(struct xfs_inode *ip)
> {
> if (ip->i_forkoff)
> return true;
> return false;
> }
>
> And then xfs_inode_hasattr() becomes:
>
> if (!xfs_inode_has_attr_fork(ip)
> return false;
> if (ip->i_af.if_format == XFS_DINODE_FMT_EXTENTS &&
> ip->i_af.if_nextents == 0)
> return false;
> ....
Ok, done.
--D
> Cheers,
>
> Dave.
> > if (ip->i_af.if_format == XFS_DINODE_FMT_EXTENTS &&
> > ip->i_af.if_nextents == 0)
> > return 0;
> > diff --git a/fs/xfs/libxfs/xfs_attr.h b/fs/xfs/libxfs/xfs_attr.h
> > index 0f100db504ee..36371c3b9069 100644
> > --- a/fs/xfs/libxfs/xfs_attr.h
> > +++ b/fs/xfs/libxfs/xfs_attr.h
> > @@ -576,7 +576,7 @@ xfs_attr_init_add_state(struct xfs_da_args *args)
> > * context, i_af is guaranteed to exist. Hence if the attr fork is
> > * null, we were called from a pure remove operation and so we are done.
> > */
> > - if (!args->dp->i_af.if_present)
> > + if (!XFS_IFORK_Q(args->dp))
> > return XFS_DAS_DONE;
> >
> > args->op_flags |= XFS_DA_OP_ADDNAME;
> > diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
> > index 4abb5b4cee0c..77ab5ac1fcbc 100644
> > --- a/fs/xfs/libxfs/xfs_bmap.c
> > +++ b/fs/xfs/libxfs/xfs_bmap.c
> > @@ -1041,7 +1041,6 @@ xfs_bmap_add_attrfork(
> > error = xfs_bmap_set_attrforkoff(ip, size, &version);
> > if (error)
> > goto trans_cancel;
> > - ASSERT(!ip->i_af.if_present);
> >
> > xfs_ifork_init_attr(ip, XFS_DINODE_FMT_EXTENTS, 0);
> > logflags = 0;
> > diff --git a/fs/xfs/libxfs/xfs_inode_buf.c b/fs/xfs/libxfs/xfs_inode_buf.c
> > index e203c80c1bf8..2aef27b042fe 100644
> > --- a/fs/xfs/libxfs/xfs_inode_buf.c
> > +++ b/fs/xfs/libxfs/xfs_inode_buf.c
> > @@ -178,7 +178,6 @@ xfs_inode_from_disk(
> > xfs_failaddr_t fa;
> >
> > ASSERT(ip->i_cowfp == NULL);
> > - ASSERT(!ip->i_af.if_present);
> >
> > fa = xfs_dinode_verify(ip->i_mount, ip->i_ino, from);
> > if (fa) {
> > diff --git a/fs/xfs/libxfs/xfs_inode_fork.c b/fs/xfs/libxfs/xfs_inode_fork.c
> > index 9d5141c21eee..b0370b837166 100644
> > --- a/fs/xfs/libxfs/xfs_inode_fork.c
> > +++ b/fs/xfs/libxfs/xfs_inode_fork.c
> > @@ -282,9 +282,6 @@ xfs_ifork_init_attr(
> > enum xfs_dinode_fmt format,
> > xfs_extnum_t nextents)
> > {
> > - ASSERT(!ip->i_af.if_present);
> > -
> > - ip->i_af.if_present = 1;
> > ip->i_af.if_format = format;
> > ip->i_af.if_nextents = nextents;
> > }
> > @@ -293,7 +290,6 @@ void
> > xfs_ifork_zap_attr(
> > struct xfs_inode *ip)
> > {
> > - ASSERT(ip->i_af.if_present);
> > ASSERT(ip->i_af.if_broot == NULL);
> > ASSERT(ip->i_af.if_u1.if_data == NULL);
> > ASSERT(ip->i_af.if_height == 0);
> > @@ -683,7 +679,6 @@ xfs_ifork_init_cow(
> >
> > ip->i_cowfp = kmem_cache_zalloc(xfs_ifork_cache,
> > GFP_NOFS | __GFP_NOFAIL);
> > - ip->i_cowfp->if_present = 1;
> > ip->i_cowfp->if_format = XFS_DINODE_FMT_EXTENTS;
> > }
> >
> > @@ -722,7 +717,7 @@ xfs_ifork_verify_local_attr(
> > struct xfs_ifork *ifp = &ip->i_af;
> > xfs_failaddr_t fa;
> >
> > - if (!ifp->if_present)
> > + if (!XFS_IFORK_Q(ip))
> > fa = __this_address;
> > else
> > fa = xfs_attr_shortform_verify(ip);
> > diff --git a/fs/xfs/libxfs/xfs_inode_fork.h b/fs/xfs/libxfs/xfs_inode_fork.h
> > index 63015e9cee14..0b912bbe4f4b 100644
> > --- a/fs/xfs/libxfs/xfs_inode_fork.h
> > +++ b/fs/xfs/libxfs/xfs_inode_fork.h
> > @@ -24,7 +24,6 @@ struct xfs_ifork {
> > xfs_extnum_t if_nextents; /* # of extents in this fork */
> > short if_broot_bytes; /* bytes allocated for root */
> > int8_t if_format; /* format of this fork */
> > - int8_t if_present; /* 1 if present */
> > };
> >
> > /*
> > diff --git a/fs/xfs/xfs_attr_inactive.c b/fs/xfs/xfs_attr_inactive.c
> > index dbe715fe92ce..ec20ad7a9001 100644
> > --- a/fs/xfs/xfs_attr_inactive.c
> > +++ b/fs/xfs/xfs_attr_inactive.c
> > @@ -362,12 +362,11 @@ xfs_attr_inactive(
> >
> > /*
> > * Invalidate and truncate the attribute fork extents. Make sure the
> > - * fork actually has attributes as otherwise the invalidation has no
> > + * fork actually has xattr blocks as otherwise the invalidation has no
> > * blocks to read and returns an error. In this case, just do the fork
> > * removal below.
> > */
> > - if (xfs_inode_hasattr(dp) &&
> > - dp->i_af.if_format != XFS_DINODE_FMT_LOCAL) {
> > + if (dp->i_af.if_nextents > 0) {
> > error = xfs_attr3_root_inactive(&trans, dp);
> > if (error)
> > goto out_cancel;
> > @@ -388,10 +387,8 @@ xfs_attr_inactive(
> > xfs_trans_cancel(trans);
> > out_destroy_fork:
> > /* kill the in-core attr fork before we drop the inode lock */
> > - if (dp->i_af.if_present) {
> > - xfs_idestroy_fork(&dp->i_af);
> > - xfs_ifork_zap_attr(dp);
> > - }
> > + xfs_idestroy_fork(&dp->i_af);
> > + xfs_ifork_zap_attr(dp);
> > if (lock_mode)
> > xfs_iunlock(dp, lock_mode);
> > return error;
> > diff --git a/fs/xfs/xfs_attr_list.c b/fs/xfs/xfs_attr_list.c
> > index 6a832ee07916..99bbbe1a0e44 100644
> > --- a/fs/xfs/xfs_attr_list.c
> > +++ b/fs/xfs/xfs_attr_list.c
> > @@ -61,7 +61,6 @@ xfs_attr_shortform_list(
> > int sbsize, nsbuf, count, i;
> > int error = 0;
> >
> > - ASSERT(dp->i_af.if_present);
> > sf = (struct xfs_attr_shortform *)dp->i_af.if_u1.if_data;
> > ASSERT(sf != NULL);
> > if (!sf->hdr.count)
> > diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
> > index e08dedfb7f9d..026c63234f8d 100644
> > --- a/fs/xfs/xfs_icache.c
> > +++ b/fs/xfs/xfs_icache.c
> > @@ -102,7 +102,6 @@ xfs_inode_alloc(
> > memset(&ip->i_af, 0, sizeof(ip->i_af));
> > ip->i_af.if_format = XFS_DINODE_FMT_EXTENTS;
> > memset(&ip->i_df, 0, sizeof(ip->i_df));
> > - ip->i_df.if_present = 1;
> > ip->i_flags = 0;
> > ip->i_delayed_blks = 0;
> > ip->i_diflags2 = mp->m_ino_geo.new_diflags2;
> > @@ -132,10 +131,9 @@ xfs_inode_free_callback(
> > break;
> > }
> >
> > - if (ip->i_af.if_present) {
> > - xfs_idestroy_fork(&ip->i_af);
> > - xfs_ifork_zap_attr(ip);
> > - }
> > + xfs_idestroy_fork(&ip->i_af);
> > + xfs_ifork_zap_attr(ip);
> > +
> > if (ip->i_cowfp) {
> > xfs_idestroy_fork(ip->i_cowfp);
> > kmem_cache_free(xfs_ifork_cache, ip->i_cowfp);
> > diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
> > index c9c26d782a38..2f559e16a4db 100644
> > --- a/fs/xfs/xfs_inode.c
> > +++ b/fs/xfs/xfs_inode.c
> > @@ -125,7 +125,7 @@ xfs_ilock_attr_map_shared(
> > {
> > uint lock_mode = XFS_ILOCK_SHARED;
> >
> > - if (ip->i_af.if_present && xfs_need_iread_extents(&ip->i_af))
> > + if (XFS_IFORK_Q(ip) && xfs_need_iread_extents(&ip->i_af))
> > lock_mode = XFS_ILOCK_EXCL;
> > xfs_ilock(ip, lock_mode);
> > return lock_mode;
> > @@ -1768,7 +1768,6 @@ xfs_inactive(
> > goto out;
> > }
> >
> > - ASSERT(!ip->i_af.if_present);
> > ASSERT(ip->i_forkoff == 0);
> >
> > /*
> > @@ -3488,7 +3487,7 @@ xfs_iflush(
> > if (ip->i_df.if_format == XFS_DINODE_FMT_LOCAL &&
> > xfs_ifork_verify_local_data(ip))
> > goto flush_out;
> > - if (ip->i_af.if_present &&
> > + if (XFS_IFORK_Q(ip) &&
> > ip->i_af.if_format == XFS_DINODE_FMT_LOCAL &&
> > xfs_ifork_verify_local_attr(ip))
> > goto flush_out;
> > diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
> > index 045bad62ac25..9bda01311c2f 100644
> > --- a/fs/xfs/xfs_inode.h
> > +++ b/fs/xfs/xfs_inode.h
> > @@ -86,7 +86,7 @@ xfs_ifork_ptr(
> > case XFS_DATA_FORK:
> > return &ip->i_df;
> > case XFS_ATTR_FORK:
> > - if (!ip->i_af.if_present)
> > + if (!XFS_IFORK_Q(ip))
> > return NULL;
> > return &ip->i_af;
> > case XFS_COW_FORK:
> >
> >
>
> --
> Dave Chinner
> david@xxxxxxxxxxxxx
