On Sun 12-04-20 22:40:44, ira.weiny@xxxxxxxxx wrote: > From: Ira Weiny <ira.weiny@xxxxxxxxx> > > DAX effective mode changes (setting of S_DAX) require inode eviction. > > Define a flag which can be set to inform the VFS layer that inodes > should not be cached. This will expedite the eviction of those nodes > requiring reload. > > Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx> This inode flag will have a limited impact because usually dentry will still hold inode reference. So until dentry is evicted, inode stays as well. So I think we'd need something like DCACHE_DONTCACHE flag as well to discard a dentry whenever dentry usecount hits zero (which will be generally on last file close). What do you think? And I'd note that checking for I_DONTCACHE flag in dput() isn't straightforward because of locking so that's why I suggest separate dentry flag. Honza > --- > include/linux/fs.h | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/include/linux/fs.h b/include/linux/fs.h > index a818ced22961..e2db71d150c3 100644 > --- a/include/linux/fs.h > +++ b/include/linux/fs.h > @@ -2151,6 +2151,8 @@ 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 Do not cache the inode > + * > * Q: What is the difference between I_WILL_FREE and I_FREEING? > */ > #define I_DIRTY_SYNC (1 << 0) > @@ -2173,6 +2175,7 @@ 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) > @@ -3042,7 +3045,8 @@ 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 > -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR