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authorNick Piggin <npiggin@kernel.dk>2011-01-07 17:49:42 +1100
committerNick Piggin <npiggin@kernel.dk>2011-01-07 17:50:24 +1100
commit357f8e658bba8a085c4a5d4331e30894be8096b8 (patch)
tree2182f5cd42a1c142bd2780bdaa7cc7953d9ec924
parent89ad485f01fd83c47f17a128db3bd7b89c0f244f (diff)
downloadlinux-357f8e658bba8a085c4a5d4331e30894be8096b8.tar.bz2
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>
-rw-r--r--fs/dcache.c24
1 files changed, 12 insertions, 12 deletions
diff --git a/fs/dcache.c b/fs/dcache.c
index ccdc5c2512df..01f016799fd4 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -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);