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Commit 2cb1599f authored by David Chinner's avatar David Chinner Committed by Lachlan McIlroy
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Inode: Allow external initialisers 



To allow XFS to combine the XFS and linux inodes into a single
structure, we need to drive inode lookup from the XFS inode cache,
not the generic inode cache. This means that we need initialise a
struct inode from a context outside alloc_inode() as it is no longer
used by XFS.

Factor and export the struct inode initialisation code from
alloc_inode() to inode_init_always() as a counterpart to
inode_init_once().  i.e. we have to call this init function for each
inode instantiation (always), as opposed inode_init_once() which is
only called on slab object instantiation (once).

Signed-off-by: default avatarDave Chinner <david@fromorbit.com>
Signed-off-by: default avatarChristoph Hellwig <hch@infradead.org>
Signed-off-by: default avatarLachlan McIlroy <lachlan@sgi.com>
parent 94b97e39

fs/inode.c

+78 −62
Original line number Diff line number Diff line
@@ -108,19 +108,20 @@ static void wake_up_inode(struct inode *inode) 
	wake_up_bit(&inode->i_state, __I_LOCK);

}



static struct inode *alloc_inode(struct super_block *sb)

/**

 * inode_init_always - perform inode structure intialisation

 * @sb		- superblock inode belongs to.

 * @inode	- inode to initialise

 *

 * These are initializations that need to be done on every inode

 * allocation as the fields are not initialised by slab allocation.

 */

struct inode *inode_init_always(struct super_block *sb, struct inode *inode)

{

	static const struct address_space_operations empty_aops;

	static struct inode_operations empty_iops;

	static const struct file_operations empty_fops;

	struct inode *inode;



	if (sb->s_op->alloc_inode)

		inode = sb->s_op->alloc_inode(sb);

	else

		inode = (struct inode *) kmem_cache_alloc(inode_cachep, GFP_KERNEL);



	if (inode) {

	struct address_space * const mapping = &inode->i_data;



	inode->i_sb = sb;
@@ -183,9 +184,24 @@ static struct inode *alloc_inode(struct super_block *sb) 
	}

	inode->i_private = NULL;

	inode->i_mapping = mapping;

	}



	return inode;

}

EXPORT_SYMBOL(inode_init_always);



static struct inode *alloc_inode(struct super_block *sb)

{

	struct inode *inode;



	if (sb->s_op->alloc_inode)

		inode = sb->s_op->alloc_inode(sb);

	else

		inode = kmem_cache_alloc(inode_cachep, GFP_KERNEL);



	if (inode)

		return inode_init_always(sb, inode);

	return NULL;

}



void destroy_inode(struct inode *inode) 

{

include/linux/fs.h

+1 −0
Original line number Diff line number Diff line
@@ -1881,6 +1881,7 @@ extern loff_t default_llseek(struct file *file, loff_t offset, int origin); 


extern loff_t vfs_llseek(struct file *file, loff_t offset, int origin);



extern struct inode * inode_init_always(struct super_block *, struct inode *);

extern void inode_init_once(struct inode *);

extern void iput(struct inode *);

extern struct inode * igrab(struct inode *);