提交 3f70bd51 编写于 作者: J J. Bruce Fields 提交者: Al Viro

dcache: move d_splice_alias

Just a trivial move to locate it near (similar) d_materialise_unique
code and save some forward references in a following patch.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
上级 d03b29a2
...@@ -1853,58 +1853,6 @@ struct dentry *d_obtain_alias(struct inode *inode) ...@@ -1853,58 +1853,6 @@ struct dentry *d_obtain_alias(struct inode *inode)
} }
EXPORT_SYMBOL(d_obtain_alias); EXPORT_SYMBOL(d_obtain_alias);
/**
* d_splice_alias - splice a disconnected dentry into the tree if one exists
* @inode: the inode which may have a disconnected dentry
* @dentry: a negative dentry which we want to point to the inode.
*
* If inode is a directory and has a 'disconnected' dentry (i.e. IS_ROOT and
* DCACHE_DISCONNECTED), then d_move that in place of the given dentry
* and return it, else simply d_add the inode to the dentry and return NULL.
*
* This is needed in the lookup routine of any filesystem that is exportable
* (via knfsd) so that we can build dcache paths to directories effectively.
*
* If a dentry was found and moved, then it is returned. Otherwise NULL
* is returned. This matches the expected return value of ->lookup.
*
* Cluster filesystems may call this function with a negative, hashed dentry.
* In that case, we know that the inode will be a regular file, and also this
* will only occur during atomic_open. So we need to check for the dentry
* being already hashed only in the final case.
*/
struct dentry *d_splice_alias(struct inode *inode, struct dentry *dentry)
{
struct dentry *new = NULL;
if (IS_ERR(inode))
return ERR_CAST(inode);
if (inode && S_ISDIR(inode->i_mode)) {
spin_lock(&inode->i_lock);
new = __d_find_alias(inode, 1);
if (new) {
BUG_ON(!(new->d_flags & DCACHE_DISCONNECTED));
spin_unlock(&inode->i_lock);
security_d_instantiate(new, inode);
d_move(new, dentry);
iput(inode);
} else {
/* already taking inode->i_lock, so d_add() by hand */
__d_instantiate(dentry, inode);
spin_unlock(&inode->i_lock);
security_d_instantiate(dentry, inode);
d_rehash(dentry);
}
} else {
d_instantiate(dentry, inode);
if (d_unhashed(dentry))
d_rehash(dentry);
}
return new;
}
EXPORT_SYMBOL(d_splice_alias);
/** /**
* d_add_ci - lookup or allocate new dentry with case-exact name * d_add_ci - lookup or allocate new dentry with case-exact name
* @inode: the inode case-insensitive lookup has found * @inode: the inode case-insensitive lookup has found
...@@ -2696,6 +2644,58 @@ static void __d_materialise_dentry(struct dentry *dentry, struct dentry *anon) ...@@ -2696,6 +2644,58 @@ static void __d_materialise_dentry(struct dentry *dentry, struct dentry *anon)
/* anon->d_lock still locked, returns locked */ /* anon->d_lock still locked, returns locked */
} }
/**
* d_splice_alias - splice a disconnected dentry into the tree if one exists
* @inode: the inode which may have a disconnected dentry
* @dentry: a negative dentry which we want to point to the inode.
*
* If inode is a directory and has a 'disconnected' dentry (i.e. IS_ROOT and
* DCACHE_DISCONNECTED), then d_move that in place of the given dentry
* and return it, else simply d_add the inode to the dentry and return NULL.
*
* This is needed in the lookup routine of any filesystem that is exportable
* (via knfsd) so that we can build dcache paths to directories effectively.
*
* If a dentry was found and moved, then it is returned. Otherwise NULL
* is returned. This matches the expected return value of ->lookup.
*
* Cluster filesystems may call this function with a negative, hashed dentry.
* In that case, we know that the inode will be a regular file, and also this
* will only occur during atomic_open. So we need to check for the dentry
* being already hashed only in the final case.
*/
struct dentry *d_splice_alias(struct inode *inode, struct dentry *dentry)
{
struct dentry *new = NULL;
if (IS_ERR(inode))
return ERR_CAST(inode);
if (inode && S_ISDIR(inode->i_mode)) {
spin_lock(&inode->i_lock);
new = __d_find_alias(inode, 1);
if (new) {
BUG_ON(!(new->d_flags & DCACHE_DISCONNECTED));
spin_unlock(&inode->i_lock);
security_d_instantiate(new, inode);
d_move(new, dentry);
iput(inode);
} else {
/* already taking inode->i_lock, so d_add() by hand */
__d_instantiate(dentry, inode);
spin_unlock(&inode->i_lock);
security_d_instantiate(dentry, inode);
d_rehash(dentry);
}
} else {
d_instantiate(dentry, inode);
if (d_unhashed(dentry))
d_rehash(dentry);
}
return new;
}
EXPORT_SYMBOL(d_splice_alias);
/** /**
* d_materialise_unique - introduce an inode into the tree * d_materialise_unique - introduce an inode into the tree
* @dentry: candidate dentry * @dentry: candidate dentry
......
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