On Tue, Apr 21, 2020 at 01:23:14PM -0700, Darrick J. Wong wrote:
> > Subject: [PATCH V9 08/11] fs: Lift XFS_IDONTCACNE to the VFS layer
>
> This still has a misspelling in the subject line.
Sorry... My reliance on spell check is thwarted by macros again! ;-)
>
> On Tue, Apr 21, 2020 at 12:17:50PM -0700, ira.weiny@xxxxxxxxx wrote:
> > From: Ira Weiny <ira.weiny@xxxxxxxxx>
> >
> > DAX effective mode (S_DAX) changes requires inode eviction.
> >
> > XFS has an advisory flag (XFS_IDONTCACHE) to prevent caching of the
> > inode if no other additional references are taken. We lift this flag to
> > the VFS layer and change the behavior slightly by allowing the flag to
> > remain even if multiple references are taken.
> >
> > This will expedite the eviction of inodes to change S_DAX.
> >
> > Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
> > Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx>
> >
> > ---
> > Changes from V8:
> > Remove XFS_IDONTCACHE
> > ---
> > fs/xfs/xfs_icache.c | 4 ++--
> > fs/xfs/xfs_inode.h | 2 +-
> > fs/xfs/xfs_super.c | 2 +-
> > include/linux/fs.h | 6 +++++-
> > 4 files changed, 9 insertions(+), 5 deletions(-)
> >
> > diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
> > index 17a0b86fe701..de76f7f60695 100644
> > --- a/fs/xfs/xfs_icache.c
> > +++ b/fs/xfs/xfs_icache.c
> > @@ -477,7 +477,7 @@ xfs_iget_cache_hit(
> > xfs_ilock(ip, lock_flags);
> >
> > if (!(flags & XFS_IGET_INCORE))
> > - xfs_iflags_clear(ip, XFS_ISTALE | XFS_IDONTCACHE);
> > + xfs_iflags_clear(ip, XFS_ISTALE);
> > XFS_STATS_INC(mp, xs_ig_found);
> >
> > return 0;
> > @@ -559,7 +559,7 @@ xfs_iget_cache_miss(
> > */
> > iflags = XFS_INEW;
> > if (flags & XFS_IGET_DONTCACHE)
> > - iflags |= XFS_IDONTCACHE;
> > + VFS_I(ip)->i_state |= I_DONTCACHE;
> > ip->i_udquot = NULL;
> > ip->i_gdquot = NULL;
> > ip->i_pdquot = NULL;
> > diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
> > index 83073c883fbf..52b8ee21a0b1 100644
> > --- a/fs/xfs/xfs_inode.h
> > +++ b/fs/xfs/xfs_inode.h
> > @@ -218,7 +218,7 @@ static inline bool xfs_inode_has_cow_data(struct xfs_inode *ip)
> > #define XFS_IFLOCK (1 << __XFS_IFLOCK_BIT)
> > #define __XFS_IPINNED_BIT 8 /* wakeup key for zero pin count */
> > #define XFS_IPINNED (1 << __XFS_IPINNED_BIT)
> > -#define XFS_IDONTCACHE (1 << 9) /* don't cache the inode long term */
> > +/* Was XFS_IDONTCACHE 9 */
> > #define XFS_IEOFBLOCKS (1 << 10)/* has the preallocblocks tag set */
>
> These are incore state flags, you can change XFS_IEOFBLOCKS to (1 << 9).
Sounds good changed.
Thanks,
Ira
>
> --D
>
> > /*
> > * If this unlinked inode is in the middle of recovery, don't let drop_inode
> > diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
> > index 0d0f74786799..2e165e226e15 100644
> > --- a/fs/xfs/xfs_super.c
> > +++ b/fs/xfs/xfs_super.c
> > @@ -742,7 +742,7 @@ xfs_fs_drop_inode(
> > return 0;
> > }
> >
> > - return generic_drop_inode(inode) || (ip->i_flags & XFS_IDONTCACHE);
> > + return generic_drop_inode(inode);
> > }
> >
> > static void
> > diff --git a/include/linux/fs.h b/include/linux/fs.h
> > index a87cc5845a02..44bd45af760f 100644
> > --- a/include/linux/fs.h
> > +++ b/include/linux/fs.h
> > @@ -2156,6 +2156,8 @@ static inline void kiocb_clone(struct kiocb *kiocb, struct kiocb *kiocb_src,
> > *
> > * I_CREATING New object's inode in the middle of setting up.
> > *
> > + * I_DONTCACHE Evict inode as soon as it is not used anymore.
> > + *
> > * Q: What is the difference between I_WILL_FREE and I_FREEING?
> > */
> > #define I_DIRTY_SYNC (1 << 0)
> > @@ -2178,6 +2180,7 @@ static inline void kiocb_clone(struct kiocb *kiocb, struct kiocb *kiocb_src,
> > #define I_WB_SWITCH (1 << 13)
> > #define I_OVL_INUSE (1 << 14)
> > #define I_CREATING (1 << 15)
> > +#define I_DONTCACHE (1 << 16)
> >
> > #define I_DIRTY_INODE (I_DIRTY_SYNC | I_DIRTY_DATASYNC)
> > #define I_DIRTY (I_DIRTY_INODE | I_DIRTY_PAGES)
> > @@ -3049,7 +3052,8 @@ extern int inode_needs_sync(struct inode *inode);
> > extern int generic_delete_inode(struct inode *inode);
> > static inline int generic_drop_inode(struct inode *inode)
> > {
> > - return !inode->i_nlink || inode_unhashed(inode);
> > + return !inode->i_nlink || inode_unhashed(inode) ||
> > + (inode->i_state & I_DONTCACHE);
> > }
> >
> > extern struct inode *ilookup5_nowait(struct super_block *sb,
> > --
> > 2.25.1
> >
