Commit 8290c35f authored by David Chinner's avatar David Chinner Committed by Lachlan McIlroy
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Inode: Allow external list initialisation



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.

After inode allocation and initialisation, we need to add the inode
to the superblock list, the in-use list, hash it and do some
accounting. This all needs to be done with the inode_lock held and
there are already several places in fs/inode.c that do this list
manipulation.  Factor out the common code, add a locking wrapper and
export the function so ti can be called from XFS.
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 2cb1599f
......@@ -550,6 +550,49 @@ static struct inode * find_inode_fast(struct super_block * sb, struct hlist_head
return node ? inode : NULL;
}
static unsigned long hash(struct super_block *sb, unsigned long hashval)
{
unsigned long tmp;
tmp = (hashval * (unsigned long)sb) ^ (GOLDEN_RATIO_PRIME + hashval) /
L1_CACHE_BYTES;
tmp = tmp ^ ((tmp ^ GOLDEN_RATIO_PRIME) >> I_HASHBITS);
return tmp & I_HASHMASK;
}
static inline void
__inode_add_to_lists(struct super_block *sb, struct hlist_head *head,
struct inode *inode)
{
inodes_stat.nr_inodes++;
list_add(&inode->i_list, &inode_in_use);
list_add(&inode->i_sb_list, &sb->s_inodes);
if (head)
hlist_add_head(&inode->i_hash, head);
}
/**
* inode_add_to_lists - add a new inode to relevant lists
* @sb - superblock inode belongs to.
* @inode - inode to mark in use
*
* When an inode is allocated it needs to be accounted for, added to the in use
* list, the owning superblock and the inode hash. This needs to be done under
* the inode_lock, so export a function to do this rather than the inode lock
* itself. We calculate the hash list to add to here so it is all internal
* which requires the caller to have already set up the inode number in the
* inode to add.
*/
void inode_add_to_lists(struct super_block *sb, struct inode *inode)
{
struct hlist_head *head = inode_hashtable + hash(sb, inode->i_ino);
spin_lock(&inode_lock);
__inode_add_to_lists(sb, head, inode);
spin_unlock(&inode_lock);
}
EXPORT_SYMBOL_GPL(inode_add_to_lists);
/**
* new_inode - obtain an inode
* @sb: superblock
......@@ -577,9 +620,7 @@ struct inode *new_inode(struct super_block *sb)
inode = alloc_inode(sb);
if (inode) {
spin_lock(&inode_lock);
inodes_stat.nr_inodes++;
list_add(&inode->i_list, &inode_in_use);
list_add(&inode->i_sb_list, &sb->s_inodes);
__inode_add_to_lists(sb, NULL, inode);
inode->i_ino = ++last_ino;
inode->i_state = 0;
spin_unlock(&inode_lock);
......@@ -638,10 +679,7 @@ static struct inode * get_new_inode(struct super_block *sb, struct hlist_head *h
if (set(inode, data))
goto set_failed;
inodes_stat.nr_inodes++;
list_add(&inode->i_list, &inode_in_use);
list_add(&inode->i_sb_list, &sb->s_inodes);
hlist_add_head(&inode->i_hash, head);
__inode_add_to_lists(sb, head, inode);
inode->i_state = I_LOCK|I_NEW;
spin_unlock(&inode_lock);
......@@ -687,10 +725,7 @@ static struct inode * get_new_inode_fast(struct super_block *sb, struct hlist_he
old = find_inode_fast(sb, head, ino);
if (!old) {
inode->i_ino = ino;
inodes_stat.nr_inodes++;
list_add(&inode->i_list, &inode_in_use);
list_add(&inode->i_sb_list, &sb->s_inodes);
hlist_add_head(&inode->i_hash, head);
__inode_add_to_lists(sb, head, inode);
inode->i_state = I_LOCK|I_NEW;
spin_unlock(&inode_lock);
......@@ -714,16 +749,6 @@ static struct inode * get_new_inode_fast(struct super_block *sb, struct hlist_he
return inode;
}
static unsigned long hash(struct super_block *sb, unsigned long hashval)
{
unsigned long tmp;
tmp = (hashval * (unsigned long)sb) ^ (GOLDEN_RATIO_PRIME + hashval) /
L1_CACHE_BYTES;
tmp = tmp ^ ((tmp ^ GOLDEN_RATIO_PRIME) >> I_HASHBITS);
return tmp & I_HASHMASK;
}
/**
* iunique - get a unique inode number
* @sb: superblock
......
......@@ -1883,6 +1883,7 @@ 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 inode_add_to_lists(struct super_block *, struct inode *);
extern void iput(struct inode *);
extern struct inode * igrab(struct inode *);
extern ino_t iunique(struct super_block *, ino_t);
......
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