fs: Lift XFS_IDONTCACHE to the VFS layer
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@zeniv.linux.org.uk>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
diff --git a/include/linux/fs.h b/include/linux/fs.h
index a87cc58..44bd45a 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,