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authorMiklos Szeredi <miklos@szeredi.hu>2005-09-09 13:10:30 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2005-09-09 14:03:45 -0700
commitb6aeadeda22a9aa322fdfcd3f4c69ccf0da5cbdd (patch)
tree794afec0eeb13722550a97783ec0cfb95e5e83cb /fs/fuse/file.c
parent9e6268db496a2592e89457537ea54a496feabb77 (diff)
downloadlinux-stericsson-b6aeadeda22a9aa322fdfcd3f4c69ccf0da5cbdd.tar.gz
[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: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'fs/fuse/file.c')
-rw-r--r--fs/fuse/file.c341
1 files changed, 341 insertions, 0 deletions
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
new file mode 100644
index 000000000000..de8c9c702461
--- /dev/null
+++ b/fs/fuse/file.c
@@ -0,0 +1,341 @@
+/*
+ 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;
+}