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Commit fd72faac authored by Miklos Szeredi's avatar Miklos Szeredi Committed by Linus Torvalds
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[PATCH] FUSE: atomic create+open 



This patch adds an atomic create+open operation.  This does not yet work if
the file type changes between lookup and create+open, but solves the
permission checking problems for the separte create and open methods.

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 31d40d74

fs/fuse/dev.c

+7 −0
Original line number Diff line number Diff line
@@ -184,6 +184,13 @@ static void request_end(struct fuse_conn *fc, struct fuse_req *req) 
		   fuse_putback_request() */

		for (i = 1; i < FUSE_MAX_OUTSTANDING; i++)

			up(&fc->outstanding_sem);

	} else if (req->in.h.opcode == FUSE_RELEASE && req->inode == NULL) {

		/* Special case for failed iget in CREATE */

		u64 nodeid = req->in.h.nodeid;

		__fuse_get_request(req);

		fuse_reset_request(req);

		fuse_send_forget(fc, req, nodeid, 1);

		putback = 0;

	}

	if (putback)

		fuse_putback_request(fc, req);

fs/fuse/dir.c

+105 −1
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
#include <linux/gfp.h>

#include <linux/sched.h>

#include <linux/namei.h>

#include <linux/mount.h>



static inline unsigned long time_to_jiffies(unsigned long sec,

					    unsigned long nsec)
@@ -134,6 +135,101 @@ static void fuse_invalidate_entry(struct dentry *entry) 
	entry->d_time = jiffies - 1;

}



static int fuse_create_open(struct inode *dir, struct dentry *entry, int mode,

			    struct nameidata *nd)

{

	int err;

	struct inode *inode;

	struct fuse_conn *fc = get_fuse_conn(dir);

	struct fuse_req *req;

	struct fuse_open_in inarg;

	struct fuse_open_out outopen;

	struct fuse_entry_out outentry;

	struct fuse_inode *fi;

	struct fuse_file *ff;

	struct file *file;

	int flags = nd->intent.open.flags - 1;



	err = -ENOSYS;

	if (fc->no_create)

		goto out;



	err = -ENAMETOOLONG;

	if (entry->d_name.len > FUSE_NAME_MAX)

		goto out;



	err = -EINTR;

	req = fuse_get_request(fc);

	if (!req)

		goto out;



	ff = fuse_file_alloc();

	if (!ff)

		goto out_put_request;



	flags &= ~O_NOCTTY;

	memset(&inarg, 0, sizeof(inarg));

	inarg.flags = flags;

	inarg.mode = mode;

	req->in.h.opcode = FUSE_CREATE;

	req->in.h.nodeid = get_node_id(dir);

	req->inode = dir;

	req->in.numargs = 2;

	req->in.args[0].size = sizeof(inarg);

	req->in.args[0].value = &inarg;

	req->in.args[1].size = entry->d_name.len + 1;

	req->in.args[1].value = entry->d_name.name;

	req->out.numargs = 2;

	req->out.args[0].size = sizeof(outentry);

	req->out.args[0].value = &outentry;

	req->out.args[1].size = sizeof(outopen);

	req->out.args[1].value = &outopen;

	request_send(fc, req);

	err = req->out.h.error;

	if (err) {

		if (err == -ENOSYS)

			fc->no_create = 1;

		goto out_free_ff;

	}



	err = -EIO;

	if (!S_ISREG(outentry.attr.mode))

		goto out_free_ff;



	inode = fuse_iget(dir->i_sb, outentry.nodeid, outentry.generation,

			  &outentry.attr);

	err = -ENOMEM;

	if (!inode) {

		flags &= ~(O_CREAT | O_EXCL | O_TRUNC);

		ff->fh = outopen.fh;

		fuse_send_release(fc, ff, outentry.nodeid, NULL, flags, 0);

		goto out_put_request;

	}

	fuse_put_request(fc, req);

	entry->d_time =	time_to_jiffies(outentry.entry_valid,

					outentry.entry_valid_nsec);

	fi = get_fuse_inode(inode);

	fi->i_time = time_to_jiffies(outentry.attr_valid,

				     outentry.attr_valid_nsec);



	d_instantiate(entry, inode);

	file = lookup_instantiate_filp(nd, entry, generic_file_open);

	if (IS_ERR(file)) {

		ff->fh = outopen.fh;

		fuse_send_release(fc, ff, outentry.nodeid, inode, flags, 0);

		return PTR_ERR(file);

	}

	fuse_finish_open(inode, file, ff, &outopen);

	return 0;



 out_free_ff:

	fuse_file_free(ff);

 out_put_request:

	fuse_put_request(fc, req);

 out:

	return err;

}



static int create_new_entry(struct fuse_conn *fc, struct fuse_req *req,

			    struct inode *dir, struct dentry *entry,

			    int mode)
@@ -208,6 +304,12 @@ static int fuse_mknod(struct inode *dir, struct dentry *entry, int mode, 
static int fuse_create(struct inode *dir, struct dentry *entry, int mode,

		       struct nameidata *nd)

{

	if (nd && (nd->flags & LOOKUP_CREATE)) {

		int err = fuse_create_open(dir, entry, mode, nd);

		if (err != -ENOSYS)

			return err;

		/* Fall back on mknod */

	}

	return fuse_mknod(dir, entry, mode, 0);

}
@@ -767,7 +869,9 @@ static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry, 
				  struct nameidata *nd)

{

	struct inode *inode;

	int err = fuse_lookup_iget(dir, entry, &inode);

	int err;



	err = fuse_lookup_iget(dir, entry, &inode);

	if (err)

		return ERR_PTR(err);

	if (inode && S_ISDIR(inode->i_mode)) {

fs/fuse/file.c

+85 −47
Original line number Diff line number Diff line
@@ -14,46 +14,18 @@ 


static struct file_operations fuse_direct_io_file_operations;



int fuse_open_common(struct inode *inode, struct file *file, int isdir)

static int fuse_send_open(struct inode *inode, struct file *file, int isdir,

			  struct fuse_open_out *outargp)

{

	struct fuse_conn *fc = get_fuse_conn(inode);

	struct fuse_req *req;

	struct fuse_open_in inarg;

	struct fuse_open_out outarg;

	struct fuse_file *ff;

	struct fuse_req *req;

	int err;



	/* VFS checks this, but only _after_ ->open() */

	if (file->f_flags & O_DIRECT)

		return -EINVAL;



	err = generic_file_open(inode, file);

	if (err)

		return err;



	/* If opening the root node, no lookup has been performed on

	   it, so the attributes must be refreshed */

	if (get_node_id(inode) == FUSE_ROOT_ID) {

		int err = fuse_do_getattr(inode);

		if (err)

		 	return err;

	}



	req = fuse_get_request(fc);

	if (!req)

		return -EINTR;



	err = -ENOMEM;

	ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL);

	if (!ff)

		goto out_put_request;



	ff->release_req = fuse_request_alloc();

	if (!ff->release_req) {

		kfree(ff);

		goto out_put_request;

	}



	memset(&inarg, 0, sizeof(inarg));

	inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);

	req->in.h.opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN;
@@ -63,44 +35,110 @@ int fuse_open_common(struct inode *inode, struct file *file, int isdir) 
	req->in.args[0].size = sizeof(inarg);

	req->in.args[0].value = &inarg;

	req->out.numargs = 1;

	req->out.args[0].size = sizeof(outarg);

	req->out.args[0].value = &outarg;

	req->out.args[0].size = sizeof(*outargp);

	req->out.args[0].value = outargp;

	request_send(fc, req);

	err = req->out.h.error;

	if (err) {

	fuse_put_request(fc, req);



	return err;

}



struct fuse_file *fuse_file_alloc(void)

{

	struct fuse_file *ff;

	ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL);

	if (ff) {

		ff->release_req = fuse_request_alloc();

		if (!ff->release_req) {

			kfree(ff);

			ff = NULL;

		}

	}

	return ff;

}



void fuse_file_free(struct fuse_file *ff)

{

	fuse_request_free(ff->release_req);

	kfree(ff);

	} else {

		if (!isdir && (outarg.open_flags & FOPEN_DIRECT_IO))

}



void fuse_finish_open(struct inode *inode, struct file *file,

		      struct fuse_file *ff, struct fuse_open_out *outarg)

{

	if (outarg->open_flags & FOPEN_DIRECT_IO)

		file->f_op = &fuse_direct_io_file_operations;

		if (!(outarg.open_flags & FOPEN_KEEP_CACHE))

	if (!(outarg->open_flags & FOPEN_KEEP_CACHE))

		invalidate_inode_pages(inode->i_mapping);

		ff->fh = outarg.fh;

	ff->fh = outarg->fh;

	file->private_data = ff;

}



 out_put_request:

	fuse_put_request(fc, req);

int fuse_open_common(struct inode *inode, struct file *file, int isdir)

{

	struct fuse_open_out outarg;

	struct fuse_file *ff;

	int err;



	/* VFS checks this, but only _after_ ->open() */

	if (file->f_flags & O_DIRECT)

		return -EINVAL;



	err = generic_file_open(inode, file);

	if (err)

		return err;



	/* If opening the root node, no lookup has been performed on

	   it, so the attributes must be refreshed */

	if (get_node_id(inode) == FUSE_ROOT_ID) {

		err = fuse_do_getattr(inode);

		if (err)

		 	return err;

	}



int fuse_release_common(struct inode *inode, struct file *file, int isdir)

	ff = fuse_file_alloc();

	if (!ff)

		return -ENOMEM;



	err = fuse_send_open(inode, file, isdir, &outarg);

	if (err)

		fuse_file_free(ff);

	else {

		if (isdir)

			outarg.open_flags &= ~FOPEN_DIRECT_IO;

		fuse_finish_open(inode, file, ff, &outarg);

	}



	return err;

}



void fuse_send_release(struct fuse_conn *fc, struct fuse_file *ff,

		       u64 nodeid, struct inode *inode, int flags, int isdir)

{

	struct fuse_conn *fc = get_fuse_conn(inode);

	struct fuse_file *ff = file->private_data;

	struct fuse_req * req = ff->release_req;

	struct fuse_release_in *inarg = &req->misc.release_in;



	inarg->fh = ff->fh;

	inarg->flags = file->f_flags & ~O_EXCL;

	inarg->flags = flags;

	req->in.h.opcode = isdir ? FUSE_RELEASEDIR : FUSE_RELEASE;

	req->in.h.nodeid = get_node_id(inode);

	req->in.h.nodeid = nodeid;

	req->inode = inode;

	req->in.numargs = 1;

	req->in.args[0].size = sizeof(struct fuse_release_in);

	req->in.args[0].value = inarg;

	request_send_background(fc, req);

	kfree(ff);

}



int fuse_release_common(struct inode *inode, struct file *file, int isdir)

{

	struct fuse_file *ff = file->private_data;

	if (ff) {

		struct fuse_conn *fc = get_fuse_conn(inode);

		u64 nodeid = get_node_id(inode);

		fuse_send_release(fc, ff, nodeid, inode, file->f_flags, isdir);

	}



	/* Return value is ignored by VFS */

	return 0;

fs/fuse/fuse_i.h

+14 −0
Original line number Diff line number Diff line
@@ -269,6 +269,9 @@ struct fuse_conn { 
	/** Is access not implemented by fs? */

	unsigned no_access : 1;



	/** Is create not implemented by fs? */

	unsigned no_create : 1;



	/** Backing dev info */

	struct backing_dev_info bdi;

};
@@ -340,6 +343,17 @@ size_t fuse_send_read_common(struct fuse_req *req, struct file *file, 
 */

int fuse_open_common(struct inode *inode, struct file *file, int isdir);



struct fuse_file *fuse_file_alloc(void);

void fuse_file_free(struct fuse_file *ff);

void fuse_finish_open(struct inode *inode, struct file *file,

		      struct fuse_file *ff, struct fuse_open_out *outarg);



/**

 * Send a RELEASE request

 */

void fuse_send_release(struct fuse_conn *fc, struct fuse_file *ff,

		       u64 nodeid, struct inode *inode, int flags, int isdir);



/**

 * Send RELEASE or RELEASEDIR request

 */

include/linux/fuse.h

+3 −2
Original line number Diff line number Diff line
@@ -100,7 +100,8 @@ enum fuse_opcode { 
	FUSE_READDIR       = 28,

	FUSE_RELEASEDIR    = 29,

	FUSE_FSYNCDIR      = 30,

	FUSE_ACCESS        = 34

	FUSE_ACCESS        = 34,

	FUSE_CREATE        = 35

};



/* Conservative buffer size for the client */
@@ -158,7 +159,7 @@ struct fuse_setattr_in { 


struct fuse_open_in {

	__u32	flags;

	__u32	padding;

	__u32	mode;

};



struct fuse_open_out {