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Commit 8cbdf1e6 authored by Miklos Szeredi's avatar Miklos Szeredi Committed by Linus Torvalds
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[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: default avatarMiklos Szeredi <miklos@szeredi.hu>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent de5f1202

fs/fuse/dir.c

+43 −21
Original line number Diff line number Diff line
@@ -23,9 +23,26 @@ static inline unsigned long time_to_jiffies(unsigned long sec, 


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 void fuse_lookup_init(struct fuse_req *req, struct inode *dir, 


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 @@ static int fuse_dentry_revalidate(struct dentry *entry, struct nameidata *nd) 
		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 @@ static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry, 
	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 @@ static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry, 
	}

	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 @@ static int fuse_unlink(struct inode *dir, struct dentry *entry) 
		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 @@ static int fuse_rmdir(struct inode *dir, struct dentry *entry) 
	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 @@ static int fuse_rename(struct inode *olddir, struct dentry *oldent, 
		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