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Commit b6aeaded authored by Miklos Szeredi's avatar Miklos Szeredi Committed by Linus Torvalds
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[PATCH] FUSE - file operations 



This patch adds the file operations of FUSE.

The following operations are added:

 o open
 o flush
 o release
 o fsync
 o readpage
 o commit_write

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 9e6268db

fs/fuse/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -4,4 +4,4 @@ 


obj-$(CONFIG_FUSE_FS) += fuse.o



fuse-objs := dev.o dir.o inode.o
 
fuse-objs := dev.o dir.o file.o inode.o

fs/fuse/dir.c

+1 −0
Original line number Diff line number Diff line
@@ -731,6 +731,7 @@ static struct inode_operations fuse_dir_inode_operations = { 
};



static struct file_operations fuse_dir_operations = {

	.llseek		= generic_file_llseek,

	.read		= generic_read_dir,

	.readdir	= fuse_readdir,

	.open		= fuse_dir_open,

fs/fuse/file.c

0 → 100644
+341 −0
Original line number Diff line number Diff line 
/*

  FUSE: Filesystem in Userspace

  Copyright (C) 2001-2005  Miklos Szeredi <miklos@szeredi.hu>



  This program can be distributed under the terms of the GNU GPL.

  See the file COPYING.

*/



#include "fuse_i.h"



#include <linux/pagemap.h>

#include <linux/slab.h>

#include <linux/kernel.h>



static int fuse_open(struct inode *inode, struct file *file)

{

	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;

	int err;

	/* Restarting the syscall is not allowed if O_CREAT and O_EXCL

	   are both set, because creation will fail on the restart */

	int excl = (file->f_flags & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL);



	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;

	}



	if (excl)

		req = fuse_get_request_nonint(fc);

	else

		req = fuse_get_request(fc);

	if (!req)

		return excl ? -EINTR : -ERESTARTSYS;



	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 = FUSE_OPEN;

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

	req->inode = inode;

	req->in.numargs = 1;

	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;

	if (excl)

		request_send_nonint(fc, req);

	else

		request_send(fc, req);

	err = req->out.h.error;

	if (!err)

		invalidate_inode_pages(inode->i_mapping);

	if (err) {

		fuse_request_free(ff->release_req);

		kfree(ff);

	} else {

		ff->fh = outarg.fh;

		file->private_data = ff;

	}



 out_put_request:

	fuse_put_request(fc, req);

	return err;

}



static int fuse_release(struct inode *inode, struct file *file)

{

	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;

	req->in.h.opcode = FUSE_RELEASE;

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

	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);



	/* Return value is ignored by VFS */

	return 0;

}



static int fuse_flush(struct file *file)

{

	struct inode *inode = file->f_dentry->d_inode;

	struct fuse_conn *fc = get_fuse_conn(inode);

	struct fuse_file *ff = file->private_data;

	struct fuse_req *req;

	struct fuse_flush_in inarg;

	int err;



	if (fc->no_flush)

		return 0;



	req = fuse_get_request_nonint(fc);

	if (!req)

		return -EINTR;



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

	inarg.fh = ff->fh;

	req->in.h.opcode = FUSE_FLUSH;

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

	req->inode = inode;

	req->file = file;

	req->in.numargs = 1;

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

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

	request_send_nonint(fc, req);

	err = req->out.h.error;

	fuse_put_request(fc, req);

	if (err == -ENOSYS) {

		fc->no_flush = 1;

		err = 0;

	}

	return err;

}



static int fuse_fsync(struct file *file, struct dentry *de, int datasync)

{

	struct inode *inode = de->d_inode;

	struct fuse_conn *fc = get_fuse_conn(inode);

	struct fuse_file *ff = file->private_data;

	struct fuse_req *req;

	struct fuse_fsync_in inarg;

	int err;



	if (fc->no_fsync)

		return 0;



	req = fuse_get_request(fc);

	if (!req)

		return -ERESTARTSYS;



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

	inarg.fh = ff->fh;

	inarg.fsync_flags = datasync ? 1 : 0;

	req->in.h.opcode = FUSE_FSYNC;

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

	req->inode = inode;

	req->file = file;

	req->in.numargs = 1;

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

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

	request_send(fc, req);

	err = req->out.h.error;

	fuse_put_request(fc, req);

	if (err == -ENOSYS) {

		fc->no_fsync = 1;

		err = 0;

	}

	return err;

}



static ssize_t fuse_send_read(struct fuse_req *req, struct file *file,

			      struct inode *inode, loff_t pos,  size_t count)

{

	struct fuse_conn *fc = get_fuse_conn(inode);

	struct fuse_file *ff = file->private_data;

	struct fuse_read_in inarg;



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

	inarg.fh = ff->fh;

	inarg.offset = pos;

	inarg.size = count;

	req->in.h.opcode = FUSE_READ;

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

	req->inode = inode;

	req->file = file;

	req->in.numargs = 1;

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

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

	req->out.argpages = 1;

	req->out.argvar = 1;

	req->out.numargs = 1;

	req->out.args[0].size = count;

	request_send_nonint(fc, req);

	return req->out.args[0].size;

}



static int fuse_readpage(struct file *file, struct page *page)

{

	struct inode *inode = page->mapping->host;

	struct fuse_conn *fc = get_fuse_conn(inode);

	loff_t pos = (loff_t) page->index << PAGE_CACHE_SHIFT;

	struct fuse_req *req = fuse_get_request_nonint(fc);

	int err = -EINTR;

	if (!req)

		goto out;



	req->out.page_zeroing = 1;

	req->num_pages = 1;

	req->pages[0] = page;

	fuse_send_read(req, file, inode, pos, PAGE_CACHE_SIZE);

	err = req->out.h.error;

	fuse_put_request(fc, req);

	if (!err)

		SetPageUptodate(page);

 out:

	unlock_page(page);

	return err;

}



static ssize_t fuse_send_write(struct fuse_req *req, struct file *file,

			       struct inode *inode, loff_t pos, size_t count)

{

	struct fuse_conn *fc = get_fuse_conn(inode);

	struct fuse_file *ff = file->private_data;

	struct fuse_write_in inarg;

	struct fuse_write_out outarg;



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

	inarg.fh = ff->fh;

	inarg.offset = pos;

	inarg.size = count;

	req->in.h.opcode = FUSE_WRITE;

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

	req->inode = inode;

	req->file = file;

	req->in.argpages = 1;

	req->in.numargs = 2;

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

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

	req->in.args[1].size = count;

	req->out.numargs = 1;

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

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

	request_send_nonint(fc, req);

	return outarg.size;

}



static int fuse_prepare_write(struct file *file, struct page *page,

			      unsigned offset, unsigned to)

{

	/* No op */

	return 0;

}



static int fuse_commit_write(struct file *file, struct page *page,

			     unsigned offset, unsigned to)

{

	int err;

	ssize_t nres;

	unsigned count = to - offset;

	struct inode *inode = page->mapping->host;

	struct fuse_conn *fc = get_fuse_conn(inode);

	loff_t pos = ((loff_t) page->index << PAGE_CACHE_SHIFT) + offset;

	struct fuse_req *req = fuse_get_request_nonint(fc);

	if (!req)

		return -EINTR;



	req->num_pages = 1;

	req->pages[0] = page;

	req->page_offset = offset;

	nres = fuse_send_write(req, file, inode, pos, count);

	err = req->out.h.error;

	fuse_put_request(fc, req);

	if (!err && nres != count)

		err = -EIO;

	if (!err) {

		pos += count;

		if (pos > i_size_read(inode))

			i_size_write(inode, pos);



		if (offset == 0 && to == PAGE_CACHE_SIZE) {

			clear_page_dirty(page);

			SetPageUptodate(page);

		}

	} else if (err == -EINTR || err == -EIO)

		fuse_invalidate_attr(inode);

	return err;

}



static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma)

{

	if ((vma->vm_flags & VM_SHARED)) {

		if ((vma->vm_flags & VM_WRITE))

			return -ENODEV;

		else

			vma->vm_flags &= ~VM_MAYWRITE;

	}

	return generic_file_mmap(file, vma);

}



static int fuse_set_page_dirty(struct page *page)

{

	printk("fuse_set_page_dirty: should not happen\n");

	dump_stack();

	return 0;

}



static struct file_operations fuse_file_operations = {

	.llseek		= generic_file_llseek,

	.read		= generic_file_read,

	.write		= generic_file_write,

	.mmap		= fuse_file_mmap,

	.open		= fuse_open,

	.flush		= fuse_flush,

	.release	= fuse_release,

	.fsync		= fuse_fsync,

	.sendfile	= generic_file_sendfile,

};



static struct address_space_operations fuse_file_aops  = {

	.readpage	= fuse_readpage,

	.prepare_write	= fuse_prepare_write,

	.commit_write	= fuse_commit_write,

	.set_page_dirty	= fuse_set_page_dirty,

};



void fuse_init_file_inode(struct inode *inode)

{

	inode->i_fop = &fuse_file_operations;

	inode->i_data.a_ops = &fuse_file_aops;

}

fs/fuse/fuse_i.h

+21 −0
Original line number Diff line number Diff line
@@ -40,6 +40,15 @@ struct fuse_inode { 
	unsigned long i_time;

};



/** FUSE specific file data */

struct fuse_file {

	/** Request reserved for flush and release */

	struct fuse_req *release_req;



	/** File handle used by userspace */

	u64 fh;

};



/** One input argument of a request */

struct fuse_in_arg {

	unsigned size;
@@ -136,6 +145,7 @@ struct fuse_req { 
	/** Data for asynchronous requests */

	union {

		struct fuse_forget_in forget_in;

		struct fuse_release_in release_in;

		struct fuse_init_in_out init_in_out;

	} misc;
@@ -200,6 +210,12 @@ struct fuse_conn { 
	/** Connection failed (version mismatch) */

	unsigned conn_error : 1;



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

	unsigned no_fsync : 1;



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

	unsigned no_flush : 1;



	/** Backing dev info */

	struct backing_dev_info bdi;

};
@@ -263,6 +279,11 @@ struct inode *fuse_iget(struct super_block *sb, unsigned long nodeid, 
void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req,

		      unsigned long nodeid, u64 nlookup);



/**

 * Initialise file operations on a regular file

 */

void fuse_init_file_inode(struct inode *inode);



/**

 * Initialise inode operations on regular files and special files

 */

fs/fuse/inode.c

+2 −0
Original line number Diff line number Diff line
@@ -124,6 +124,7 @@ static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr) 
	i_size_write(inode, attr->size);

	if (S_ISREG(inode->i_mode)) {

		fuse_init_common(inode);

		fuse_init_file_inode(inode);

	} else if (S_ISDIR(inode->i_mode))

		fuse_init_dir(inode);

	else if (S_ISLNK(inode->i_mode))
@@ -137,6 +138,7 @@ static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr) 
		/* Don't let user create weird files */

		inode->i_mode = S_IFREG;

		fuse_init_common(inode);

		fuse_init_file_inode(inode);

	}

}