[PATCH] fuse: support caching negative dentries
Add support for caching negative dentries.
Up till now, ->d_revalidate() always forced a new lookup on these. Now let
the lookup method return a zero node ID (not used for anything else) meaning a
negative entry, but with a positive cache timeout. The old way of signaling
negative entry (replying ENOENT) still works.
Userspace should check the ABI minor version to see whether sending a zero ID
is allowed by the kernel or not.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 0d1438a..4c127f2 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -23,9 +23,26 @@
static void fuse_change_timeout(struct dentry *entry, struct fuse_entry_out *o)
{
- struct fuse_inode *fi = get_fuse_inode(entry->d_inode);
entry->d_time = time_to_jiffies(o->entry_valid, o->entry_valid_nsec);
- fi->i_time = time_to_jiffies(o->attr_valid, o->attr_valid_nsec);
+ if (entry->d_inode)
+ get_fuse_inode(entry->d_inode)->i_time =
+ time_to_jiffies(o->attr_valid, o->attr_valid_nsec);
+}
+
+void fuse_invalidate_attr(struct inode *inode)
+{
+ get_fuse_inode(inode)->i_time = jiffies - 1;
+}
+
+static void fuse_invalidate_entry_cache(struct dentry *entry)
+{
+ entry->d_time = jiffies - 1;
+}
+
+static void fuse_invalidate_entry(struct dentry *entry)
+{
+ d_invalidate(entry);
+ fuse_invalidate_entry_cache(entry);
}
static void fuse_lookup_init(struct fuse_req *req, struct inode *dir,
@@ -45,15 +62,22 @@
static int fuse_dentry_revalidate(struct dentry *entry, struct nameidata *nd)
{
- if (!entry->d_inode || is_bad_inode(entry->d_inode))
+ struct inode *inode = entry->d_inode;
+
+ if (inode && is_bad_inode(inode))
return 0;
else if (time_after(jiffies, entry->d_time)) {
int err;
struct fuse_entry_out outarg;
- struct inode *inode = entry->d_inode;
- struct fuse_inode *fi = get_fuse_inode(inode);
- struct fuse_conn *fc = get_fuse_conn(inode);
- struct fuse_req *req = fuse_get_request(fc);
+ struct fuse_conn *fc;
+ struct fuse_req *req;
+
+ fuse_invalidate_entry_cache(entry);
+ if (!inode)
+ return 0;
+
+ fc = get_fuse_conn(inode);
+ req = fuse_get_request(fc);
if (!req)
return 0;
@@ -61,6 +85,7 @@
request_send(fc, req);
err = req->out.h.error;
if (!err) {
+ struct fuse_inode *fi = get_fuse_inode(inode);
if (outarg.nodeid != get_node_id(inode)) {
fuse_send_forget(fc, req, outarg.nodeid, 1);
return 0;
@@ -118,9 +143,9 @@
fuse_lookup_init(req, dir, entry, &outarg);
request_send(fc, req);
err = req->out.h.error;
- if (!err && invalid_nodeid(outarg.nodeid))
+ if (!err && outarg.nodeid && invalid_nodeid(outarg.nodeid))
err = -EIO;
- if (!err) {
+ if (!err && outarg.nodeid) {
inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation,
&outarg.attr);
if (!inode) {
@@ -138,22 +163,13 @@
}
d_add(entry, inode);
entry->d_op = &fuse_dentry_operations;
- if (inode)
+ if (!err)
fuse_change_timeout(entry, &outarg);
+ else
+ fuse_invalidate_entry_cache(entry);
return NULL;
}
-void fuse_invalidate_attr(struct inode *inode)
-{
- get_fuse_inode(inode)->i_time = jiffies - 1;
-}
-
-static void fuse_invalidate_entry(struct dentry *entry)
-{
- d_invalidate(entry);
- entry->d_time = jiffies - 1;
-}
-
static int fuse_create_open(struct inode *dir, struct dentry *entry, int mode,
struct nameidata *nd)
{
@@ -387,6 +403,7 @@
inode->i_nlink = 0;
fuse_invalidate_attr(inode);
fuse_invalidate_attr(dir);
+ fuse_invalidate_entry_cache(entry);
} else if (err == -EINTR)
fuse_invalidate_entry(entry);
return err;
@@ -412,6 +429,7 @@
if (!err) {
entry->d_inode->i_nlink = 0;
fuse_invalidate_attr(dir);
+ fuse_invalidate_entry_cache(entry);
} else if (err == -EINTR)
fuse_invalidate_entry(entry);
return err;
@@ -447,6 +465,10 @@
fuse_invalidate_attr(olddir);
if (olddir != newdir)
fuse_invalidate_attr(newdir);
+
+ /* newent will end up negative */
+ if (newent->d_inode)
+ fuse_invalidate_entry_cache(newent);
} else if (err == -EINTR) {
/* If request was interrupted, DEITY only knows if the
rename actually took place. If the invalidation