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authorNick Piggin <npiggin@kernel.dk>2011-01-07 17:50:07 +1100
committerNick Piggin <npiggin@kernel.dk>2011-01-07 17:50:32 +1100
commit4b936885ab04dc6e0bb0ef35e0e23c1a7364d9e5 (patch)
treea0173d27c1ce39f173be404d269c2f15144072ab /fs
parent873feea09ebc980cbd3631b767356ce1eee65ec1 (diff)
fs: improve scalability of pseudo filesystems
Regardless of how much we possibly try to scale dcache, there is likely always going to be some fundamental contention when adding or removing children under the same parent. Pseudo filesystems do not seem need to have connected dentries because by definition they are disconnected. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Diffstat (limited to 'fs')
-rw-r--r--fs/anon_inodes.c2
-rw-r--r--fs/dcache.c12
-rw-r--r--fs/pipe.c2
3 files changed, 14 insertions, 2 deletions
diff --git a/fs/anon_inodes.c b/fs/anon_inodes.c
index aca8806fa20..9d92b33da8a 100644
--- a/fs/anon_inodes.c
+++ b/fs/anon_inodes.c
@@ -102,7 +102,7 @@ struct file *anon_inode_getfile(const char *name,
this.name = name;
this.len = strlen(name);
this.hash = 0;
- path.dentry = d_alloc(anon_inode_mnt->mnt_sb->s_root, &this);
+ path.dentry = d_alloc_pseudo(anon_inode_mnt->mnt_sb, &this);
if (!path.dentry)
goto err_module;
diff --git a/fs/dcache.c b/fs/dcache.c
index 09ec945f3c9..9e6e6db7686 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1330,6 +1330,18 @@ struct dentry *d_alloc(struct dentry * parent, const struct qstr *name)
}
EXPORT_SYMBOL(d_alloc);
+struct dentry *d_alloc_pseudo(struct super_block *sb, const struct qstr *name)
+{
+ struct dentry *dentry = d_alloc(NULL, name);
+ if (dentry) {
+ dentry->d_sb = sb;
+ dentry->d_parent = dentry;
+ dentry->d_flags |= DCACHE_DISCONNECTED;
+ }
+ return dentry;
+}
+EXPORT_SYMBOL(d_alloc_pseudo);
+
struct dentry *d_alloc_name(struct dentry *parent, const char *name)
{
struct qstr q;
diff --git a/fs/pipe.c b/fs/pipe.c
index 01a78656781..cfe3a7f2ee2 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -999,7 +999,7 @@ struct file *create_write_pipe(int flags)
goto err;
err = -ENOMEM;
- path.dentry = d_alloc(pipe_mnt->mnt_sb->s_root, &name);
+ path.dentry = d_alloc_pseudo(pipe_mnt->mnt_sb, &name);
if (!path.dentry)
goto err_inode;
path.mnt = mntget(pipe_mnt);