[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>

diff --git a/fs/fuse/Makefile b/fs/fuse/Makefile
index c34e268..c3e1f76 100644 (file)
--- a/fs/fuse/Makefile
+++ b/fs/fuse/Makefile
@@ -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

diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 92c7188..8adc1ee 100644 (file)
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -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,

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
new file mode 100644 (file)
index 0000000..de8c9c7
--- /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;
+}

diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 87d25b8..b4aa8f7 100644 (file)
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -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;
 };
@@ -264,6 +280,11 @@ 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
  */
 void fuse_init_common(struct inode *inode);

diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index fa03f80..f229d69 100644 (file)
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -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);
        }
 }
 

diff --git a/include/linux/fuse.h b/include/linux/fuse.h
index 19d69a3..61f3463 100644 (file)
--- a/include/linux/fuse.h
+++ b/include/linux/fuse.h
@@ -74,7 +74,13 @@ enum fuse_opcode {
        FUSE_RMDIR         = 11,
        FUSE_RENAME        = 12,
        FUSE_LINK          = 13,
+       FUSE_OPEN          = 14,
+       FUSE_READ          = 15,
+       FUSE_WRITE         = 16,
        FUSE_STATFS        = 17,
+       FUSE_RELEASE       = 18,
+       FUSE_FSYNC         = 20,
+       FUSE_FLUSH         = 25,
        FUSE_INIT          = 26
 };
 
@@ -132,10 +138,51 @@ struct fuse_setattr_in {
        struct fuse_attr attr;
 };
 
+struct fuse_open_in {
+       __u32   flags;
+};
+
+struct fuse_open_out {
+       __u64   fh;
+       __u32   open_flags;
+};
+
+struct fuse_release_in {
+       __u64   fh;
+       __u32   flags;
+};
+
+struct fuse_flush_in {
+       __u64   fh;
+       __u32   flush_flags;
+};
+
+struct fuse_read_in {
+       __u64   fh;
+       __u64   offset;
+       __u32   size;
+};
+
+struct fuse_write_in {
+       __u64   fh;
+       __u64   offset;
+       __u32   size;
+       __u32   write_flags;
+};
+
+struct fuse_write_out {
+       __u32   size;
+};
+
 struct fuse_statfs_out {
        struct fuse_kstatfs st;
 };
 
+struct fuse_fsync_in {
+       __u64   fh;
+       __u32   fsync_flags;
+};
+
 struct fuse_init_in_out {
        __u32   major;
        __u32   minor;