b6aeadeda2
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: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
342 lines
8.3 KiB
C
342 lines
8.3 KiB
C
/*
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FUSE: Filesystem in Userspace
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Copyright (C) 2001-2005 Miklos Szeredi <miklos@szeredi.hu>
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This program can be distributed under the terms of the GNU GPL.
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See the file COPYING.
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*/
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#include "fuse_i.h"
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#include <linux/pagemap.h>
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#include <linux/slab.h>
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#include <linux/kernel.h>
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static int fuse_open(struct inode *inode, struct file *file)
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{
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struct fuse_conn *fc = get_fuse_conn(inode);
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struct fuse_req *req;
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struct fuse_open_in inarg;
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struct fuse_open_out outarg;
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struct fuse_file *ff;
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int err;
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/* Restarting the syscall is not allowed if O_CREAT and O_EXCL
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are both set, because creation will fail on the restart */
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int excl = (file->f_flags & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL);
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err = generic_file_open(inode, file);
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if (err)
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return err;
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/* If opening the root node, no lookup has been performed on
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it, so the attributes must be refreshed */
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if (get_node_id(inode) == FUSE_ROOT_ID) {
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int err = fuse_do_getattr(inode);
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if (err)
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return err;
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}
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if (excl)
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req = fuse_get_request_nonint(fc);
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else
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req = fuse_get_request(fc);
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if (!req)
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return excl ? -EINTR : -ERESTARTSYS;
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err = -ENOMEM;
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ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL);
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if (!ff)
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goto out_put_request;
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ff->release_req = fuse_request_alloc();
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if (!ff->release_req) {
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kfree(ff);
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goto out_put_request;
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}
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memset(&inarg, 0, sizeof(inarg));
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inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
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req->in.h.opcode = FUSE_OPEN;
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req->in.h.nodeid = get_node_id(inode);
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req->inode = inode;
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req->in.numargs = 1;
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req->in.args[0].size = sizeof(inarg);
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req->in.args[0].value = &inarg;
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req->out.numargs = 1;
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req->out.args[0].size = sizeof(outarg);
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req->out.args[0].value = &outarg;
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if (excl)
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request_send_nonint(fc, req);
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else
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request_send(fc, req);
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err = req->out.h.error;
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if (!err)
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invalidate_inode_pages(inode->i_mapping);
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if (err) {
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fuse_request_free(ff->release_req);
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kfree(ff);
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} else {
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ff->fh = outarg.fh;
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file->private_data = ff;
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}
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out_put_request:
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fuse_put_request(fc, req);
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return err;
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}
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static int fuse_release(struct inode *inode, struct file *file)
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{
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struct fuse_conn *fc = get_fuse_conn(inode);
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struct fuse_file *ff = file->private_data;
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struct fuse_req *req = ff->release_req;
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struct fuse_release_in *inarg = &req->misc.release_in;
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inarg->fh = ff->fh;
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inarg->flags = file->f_flags & ~O_EXCL;
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req->in.h.opcode = FUSE_RELEASE;
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req->in.h.nodeid = get_node_id(inode);
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req->inode = inode;
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req->in.numargs = 1;
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req->in.args[0].size = sizeof(struct fuse_release_in);
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req->in.args[0].value = inarg;
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request_send_background(fc, req);
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kfree(ff);
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/* Return value is ignored by VFS */
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return 0;
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}
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static int fuse_flush(struct file *file)
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{
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struct inode *inode = file->f_dentry->d_inode;
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struct fuse_conn *fc = get_fuse_conn(inode);
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struct fuse_file *ff = file->private_data;
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struct fuse_req *req;
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struct fuse_flush_in inarg;
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int err;
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if (fc->no_flush)
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return 0;
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req = fuse_get_request_nonint(fc);
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if (!req)
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return -EINTR;
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memset(&inarg, 0, sizeof(inarg));
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inarg.fh = ff->fh;
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req->in.h.opcode = FUSE_FLUSH;
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req->in.h.nodeid = get_node_id(inode);
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req->inode = inode;
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req->file = file;
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req->in.numargs = 1;
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req->in.args[0].size = sizeof(inarg);
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req->in.args[0].value = &inarg;
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request_send_nonint(fc, req);
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err = req->out.h.error;
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fuse_put_request(fc, req);
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if (err == -ENOSYS) {
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fc->no_flush = 1;
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err = 0;
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}
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return err;
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}
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static int fuse_fsync(struct file *file, struct dentry *de, int datasync)
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{
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struct inode *inode = de->d_inode;
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struct fuse_conn *fc = get_fuse_conn(inode);
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struct fuse_file *ff = file->private_data;
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struct fuse_req *req;
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struct fuse_fsync_in inarg;
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int err;
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if (fc->no_fsync)
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return 0;
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req = fuse_get_request(fc);
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if (!req)
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return -ERESTARTSYS;
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memset(&inarg, 0, sizeof(inarg));
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inarg.fh = ff->fh;
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inarg.fsync_flags = datasync ? 1 : 0;
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req->in.h.opcode = FUSE_FSYNC;
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req->in.h.nodeid = get_node_id(inode);
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req->inode = inode;
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req->file = file;
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req->in.numargs = 1;
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req->in.args[0].size = sizeof(inarg);
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req->in.args[0].value = &inarg;
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request_send(fc, req);
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err = req->out.h.error;
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fuse_put_request(fc, req);
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if (err == -ENOSYS) {
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fc->no_fsync = 1;
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err = 0;
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}
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return err;
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}
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static ssize_t fuse_send_read(struct fuse_req *req, struct file *file,
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struct inode *inode, loff_t pos, size_t count)
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{
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struct fuse_conn *fc = get_fuse_conn(inode);
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struct fuse_file *ff = file->private_data;
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struct fuse_read_in inarg;
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memset(&inarg, 0, sizeof(struct fuse_read_in));
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inarg.fh = ff->fh;
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inarg.offset = pos;
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inarg.size = count;
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req->in.h.opcode = FUSE_READ;
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req->in.h.nodeid = get_node_id(inode);
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req->inode = inode;
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req->file = file;
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req->in.numargs = 1;
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req->in.args[0].size = sizeof(struct fuse_read_in);
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req->in.args[0].value = &inarg;
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req->out.argpages = 1;
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req->out.argvar = 1;
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req->out.numargs = 1;
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req->out.args[0].size = count;
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request_send_nonint(fc, req);
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return req->out.args[0].size;
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}
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static int fuse_readpage(struct file *file, struct page *page)
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{
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struct inode *inode = page->mapping->host;
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struct fuse_conn *fc = get_fuse_conn(inode);
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loff_t pos = (loff_t) page->index << PAGE_CACHE_SHIFT;
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struct fuse_req *req = fuse_get_request_nonint(fc);
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int err = -EINTR;
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if (!req)
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goto out;
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req->out.page_zeroing = 1;
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req->num_pages = 1;
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req->pages[0] = page;
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fuse_send_read(req, file, inode, pos, PAGE_CACHE_SIZE);
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err = req->out.h.error;
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fuse_put_request(fc, req);
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if (!err)
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SetPageUptodate(page);
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out:
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unlock_page(page);
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return err;
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}
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static ssize_t fuse_send_write(struct fuse_req *req, struct file *file,
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struct inode *inode, loff_t pos, size_t count)
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{
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struct fuse_conn *fc = get_fuse_conn(inode);
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struct fuse_file *ff = file->private_data;
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struct fuse_write_in inarg;
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struct fuse_write_out outarg;
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memset(&inarg, 0, sizeof(struct fuse_write_in));
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inarg.fh = ff->fh;
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inarg.offset = pos;
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inarg.size = count;
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req->in.h.opcode = FUSE_WRITE;
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req->in.h.nodeid = get_node_id(inode);
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req->inode = inode;
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req->file = file;
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req->in.argpages = 1;
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req->in.numargs = 2;
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req->in.args[0].size = sizeof(struct fuse_write_in);
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req->in.args[0].value = &inarg;
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req->in.args[1].size = count;
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req->out.numargs = 1;
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req->out.args[0].size = sizeof(struct fuse_write_out);
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req->out.args[0].value = &outarg;
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request_send_nonint(fc, req);
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return outarg.size;
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}
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static int fuse_prepare_write(struct file *file, struct page *page,
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unsigned offset, unsigned to)
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{
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/* No op */
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return 0;
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}
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static int fuse_commit_write(struct file *file, struct page *page,
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unsigned offset, unsigned to)
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{
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int err;
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ssize_t nres;
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unsigned count = to - offset;
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struct inode *inode = page->mapping->host;
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struct fuse_conn *fc = get_fuse_conn(inode);
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loff_t pos = ((loff_t) page->index << PAGE_CACHE_SHIFT) + offset;
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struct fuse_req *req = fuse_get_request_nonint(fc);
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if (!req)
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return -EINTR;
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req->num_pages = 1;
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req->pages[0] = page;
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req->page_offset = offset;
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nres = fuse_send_write(req, file, inode, pos, count);
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err = req->out.h.error;
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fuse_put_request(fc, req);
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if (!err && nres != count)
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err = -EIO;
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if (!err) {
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pos += count;
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if (pos > i_size_read(inode))
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i_size_write(inode, pos);
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if (offset == 0 && to == PAGE_CACHE_SIZE) {
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clear_page_dirty(page);
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SetPageUptodate(page);
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}
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} else if (err == -EINTR || err == -EIO)
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fuse_invalidate_attr(inode);
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return err;
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}
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static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma)
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{
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if ((vma->vm_flags & VM_SHARED)) {
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if ((vma->vm_flags & VM_WRITE))
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return -ENODEV;
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else
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vma->vm_flags &= ~VM_MAYWRITE;
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}
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return generic_file_mmap(file, vma);
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}
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static int fuse_set_page_dirty(struct page *page)
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{
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printk("fuse_set_page_dirty: should not happen\n");
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dump_stack();
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return 0;
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}
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static struct file_operations fuse_file_operations = {
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.llseek = generic_file_llseek,
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.read = generic_file_read,
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.write = generic_file_write,
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.mmap = fuse_file_mmap,
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.open = fuse_open,
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.flush = fuse_flush,
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.release = fuse_release,
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.fsync = fuse_fsync,
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.sendfile = generic_file_sendfile,
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};
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static struct address_space_operations fuse_file_aops = {
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.readpage = fuse_readpage,
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.prepare_write = fuse_prepare_write,
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.commit_write = fuse_commit_write,
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.set_page_dirty = fuse_set_page_dirty,
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};
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void fuse_init_file_inode(struct inode *inode)
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{
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inode->i_fop = &fuse_file_operations;
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inode->i_data.a_ops = &fuse_file_aops;
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}
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