Commit 2c567af4 authored by Ira Weiny's avatar Ira Weiny Committed by Darrick J. Wong
Browse files

fs: Introduce DCACHE_DONTCACHE 



DCACHE_DONTCACHE indicates a dentry should not be cached on final
dput().

Also add a helper function to mark DCACHE_DONTCACHE on all dentries
pointing to a specific inode when that inode is being set I_DONTCACHE.

This facilitates dropping dentry references to inodes sooner which
require eviction to swap S_DAX mode.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarIra Weiny <ira.weiny@intel.com>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Reviewed-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
parent dae2f8ed

fs/dcache.c

+19 −0
Original line number Diff line number Diff line
@@ -647,6 +647,10 @@ static inline bool retain_dentry(struct dentry *dentry) 
		if (dentry->d_op->d_delete(dentry))

			return false;

	}



	if (unlikely(dentry->d_flags & DCACHE_DONTCACHE))

		return false;



	/* retain; LRU fodder */

	dentry->d_lockref.count--;

	if (unlikely(!(dentry->d_flags & DCACHE_LRU_LIST)))
@@ -656,6 +660,21 @@ static inline bool retain_dentry(struct dentry *dentry) 
	return true;

}



void d_mark_dontcache(struct inode *inode)

{

	struct dentry *de;



	spin_lock(&inode->i_lock);

	hlist_for_each_entry(de, &inode->i_dentry, d_u.d_alias) {

		spin_lock(&de->d_lock);

		de->d_flags |= DCACHE_DONTCACHE;

		spin_unlock(&de->d_lock);

	}

	inode->i_state |= I_DONTCACHE;

	spin_unlock(&inode->i_lock);

}

EXPORT_SYMBOL(d_mark_dontcache);



/*

 * Finish off a dentry we've decided to kill.

 * dentry->d_lock must be held, returns with it unlocked.

fs/xfs/xfs_icache.c

+1 −1
Original line number Diff line number Diff line
@@ -561,7 +561,7 @@ xfs_iget_cache_miss( 
	 */

	iflags = XFS_INEW;

	if (flags & XFS_IGET_DONTCACHE)

		VFS_I(ip)->i_state |= I_DONTCACHE;

		d_mark_dontcache(VFS_I(ip));

	ip->i_udquot = NULL;

	ip->i_gdquot = NULL;

	ip->i_pdquot = NULL;

include/linux/dcache.h

+2 −0
Original line number Diff line number Diff line
@@ -177,6 +177,8 @@ struct dentry_operations { 


#define DCACHE_REFERENCED		0x00000040 /* Recently used, don't discard. */



#define DCACHE_DONTCACHE		0x00000080 /* Purge from memory on final dput() */



#define DCACHE_CANT_MOUNT		0x00000100

#define DCACHE_GENOCIDE			0x00000200

#define DCACHE_SHRINK_LIST		0x00000400

include/linux/fs.h

+1 −0
Original line number Diff line number Diff line
@@ -3055,6 +3055,7 @@ static inline int generic_drop_inode(struct inode *inode) 
	return !inode->i_nlink || inode_unhashed(inode) ||

		(inode->i_state & I_DONTCACHE);

}

extern void d_mark_dontcache(struct inode *inode);



extern struct inode *ilookup5_nowait(struct super_block *sb,

		unsigned long hashval, int (*test)(struct inode *, void *),

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