fs: dcache reduce dcache_inode_lock

dcache_inode_lock can be avoided in d_delete() and d_materialise_unique()
in cases where it is not required.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
This commit is contained in:
Nick Piggin 2011-01-07 17:49:42 +11:00
parent 89ad485f01
commit 357f8e658b

View file

@ -1828,10 +1828,15 @@ void d_delete(struct dentry * dentry)
/*
* Are we the only user?
*/
spin_lock(&dcache_inode_lock);
again:
spin_lock(&dentry->d_lock);
isdir = S_ISDIR(dentry->d_inode->i_mode);
if (dentry->d_count == 1) {
if (!spin_trylock(&dcache_inode_lock)) {
spin_unlock(&dentry->d_lock);
cpu_relax();
goto again;
}
dentry->d_flags &= ~DCACHE_CANT_MOUNT;
dentry_iput(dentry);
fsnotify_nameremove(dentry, isdir);
@ -1842,7 +1847,6 @@ void d_delete(struct dentry * dentry)
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
spin_unlock(&dcache_inode_lock);
fsnotify_nameremove(dentry, isdir);
}
@ -2164,14 +2168,15 @@ struct dentry *d_materialise_unique(struct dentry *dentry, struct inode *inode)
BUG_ON(!d_unhashed(dentry));
spin_lock(&dcache_inode_lock);
if (!inode) {
actual = dentry;
__d_instantiate(dentry, NULL);
goto found_lock;
d_rehash(actual);
goto out_nolock;
}
spin_lock(&dcache_inode_lock);
if (S_ISDIR(inode->i_mode)) {
struct dentry *alias;
@ -2198,10 +2203,9 @@ struct dentry *d_materialise_unique(struct dentry *dentry, struct inode *inode)
actual = __d_instantiate_unique(dentry, inode);
if (!actual)
actual = dentry;
else if (unlikely(!d_unhashed(actual)))
goto shouldnt_be_hashed;
else
BUG_ON(!d_unhashed(actual));
found_lock:
spin_lock(&actual->d_lock);
found:
spin_lock(&dcache_hash_lock);
@ -2217,10 +2221,6 @@ out_nolock:
iput(inode);
return actual;
shouldnt_be_hashed:
spin_unlock(&dcache_inode_lock);
BUG();
}
EXPORT_SYMBOL_GPL(d_materialise_unique);