1 files changed, 555 insertions, 0 deletions

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
new file mode 100644
index 000000000000..6454022b0536
--- /dev/null
+++ b/fs/fuse/file.c
@@ -0,0 +1,555 @@
+/*
+  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 struct file_operations fuse_direct_io_file_operations;
+
+int fuse_open_common(struct inode *inode, struct file *file, int isdir)
+{
+        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;
+
+        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;
+        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;
+        request_send(fc, req);
+        err = req->out.h.error;
+        if (err) {
+                fuse_request_free(ff->release_req);
+                kfree(ff);
+        } else {
+                if (!isdir && (outarg.open_flags & FOPEN_DIRECT_IO))
+                        file->f_op = &fuse_direct_io_file_operations;
+                if (!(outarg.open_flags & FOPEN_KEEP_CACHE))
+                        invalidate_inode_pages(inode->i_mapping);
+                ff->fh = outarg.fh;
+                file->private_data = ff;
+        }
+
+ out_put_request:
+        fuse_put_request(fc, req);
+        return err;
+}
+
+int fuse_release_common(struct inode *inode, struct file *file, 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;
+        req->in.h.opcode = isdir ? FUSE_RELEASEDIR : 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_open(struct inode *inode, struct file *file)
+{
+        return fuse_open_common(inode, file, 0);
+}
+
+static int fuse_release(struct inode *inode, struct file *file)
+{
+        return fuse_release_common(inode, file, 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(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(fc, req);
+        err = req->out.h.error;
+        fuse_put_request(fc, req);
+        if (err == -ENOSYS) {
+                fc->no_flush = 1;
+                err = 0;
+        }
+        return err;
+}
+
+int fuse_fsync_common(struct file *file, struct dentry *de, int datasync,
+                      int isdir)
+{
+        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 ((!isdir && fc->no_fsync) || (isdir && fc->no_fsyncdir))
+                return 0;
+
+        req = fuse_get_request(fc);
+        if (!req)
+                return -EINTR;
+
+        memset(&inarg, 0, sizeof(inarg));
+        inarg.fh = ff->fh;
+        inarg.fsync_flags = datasync ? 1 : 0;
+        req->in.h.opcode = isdir ? FUSE_FSYNCDIR : 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) {
+                if (isdir)
+                        fc->no_fsyncdir = 1;
+                else
+                        fc->no_fsync = 1;
+                err = 0;
+        }
+        return err;
+}
+
+static int fuse_fsync(struct file *file, struct dentry *de, int datasync)
+{
+        return fuse_fsync_common(file, de, datasync, 0);
+}
+
+size_t fuse_send_read_common(struct fuse_req *req, struct file *file,
+                             struct inode *inode, loff_t pos, size_t count,
+                             int isdir)
+{
+        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 = isdir ? FUSE_READDIR : 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(fc, req);
+        return req->out.args[0].size;
+}
+
+static inline size_t fuse_send_read(struct fuse_req *req, struct file *file,
+                                    struct inode *inode, loff_t pos,
+                                    size_t count)
+{
+        return fuse_send_read_common(req, file, inode, pos, count, 0);
+}
+
+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(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);
+        fuse_invalidate_attr(inode); /* atime changed */
+ out:
+        unlock_page(page);
+        return err;
+}
+
+static int fuse_send_readpages(struct fuse_req *req, struct file *file,
+                               struct inode *inode)
+{
+        loff_t pos = (loff_t) req->pages[0]->index << PAGE_CACHE_SHIFT;
+        size_t count = req->num_pages << PAGE_CACHE_SHIFT;
+        unsigned i;
+        req->out.page_zeroing = 1;
+        fuse_send_read(req, file, inode, pos, count);
+        for (i = 0; i < req->num_pages; i++) {
+                struct page *page = req->pages[i];
+                if (!req->out.h.error)
+                        SetPageUptodate(page);
+                unlock_page(page);
+        }
+        return req->out.h.error;
+}
+
+struct fuse_readpages_data {
+        struct fuse_req *req;
+        struct file *file;
+        struct inode *inode;
+};
+
+static int fuse_readpages_fill(void *_data, struct page *page)
+{
+        struct fuse_readpages_data *data = _data;
+        struct fuse_req *req = data->req;
+        struct inode *inode = data->inode;
+        struct fuse_conn *fc = get_fuse_conn(inode);
+
+        if (req->num_pages &&
+            (req->num_pages == FUSE_MAX_PAGES_PER_REQ ||
+             (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read ||
+             req->pages[req->num_pages - 1]->index + 1 != page->index)) {
+                int err = fuse_send_readpages(req, data->file, inode);
+                if (err) {
+                        unlock_page(page);
+                        return err;
+                }
+                fuse_reset_request(req);
+        }
+        req->pages[req->num_pages] = page;
+        req->num_pages ++;
+        return 0;
+}
+
+static int fuse_readpages(struct file *file, struct address_space *mapping,
+                          struct list_head *pages, unsigned nr_pages)
+{
+        struct inode *inode = mapping->host;
+        struct fuse_conn *fc = get_fuse_conn(inode);
+        struct fuse_readpages_data data;
+        int err;
+        data.file = file;
+        data.inode = inode;
+        data.req = fuse_get_request(fc);
+        if (!data.req)
+                return -EINTR;
+
+        err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
+        if (!err && data.req->num_pages)
+                err = fuse_send_readpages(data.req, file, inode);
+        fuse_put_request(fc, data.req);
+        fuse_invalidate_attr(inode); /* atime changed */
+        return err;
+}
+
+static size_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(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;
+        size_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(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);
+                }
+        }
+        fuse_invalidate_attr(inode);
+        return err;
+}
+
+static void fuse_release_user_pages(struct fuse_req *req, int write)
+{
+        unsigned i;
+
+        for (i = 0; i < req->num_pages; i++) {
+                struct page *page = req->pages[i];
+                if (write)
+                        set_page_dirty_lock(page);
+                put_page(page);
+        }
+}
+
+static int fuse_get_user_pages(struct fuse_req *req, const char __user *buf,
+                               unsigned nbytes, int write)
+{
+        unsigned long user_addr = (unsigned long) buf;
+        unsigned offset = user_addr & ~PAGE_MASK;
+        int npages;
+
+        /* This doesn't work with nfsd */
+        if (!current->mm)
+                return -EPERM;
+
+        nbytes = min(nbytes, (unsigned) FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT);
+        npages = (nbytes + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
+        npages = min(npages, FUSE_MAX_PAGES_PER_REQ);
+        down_read(&current->mm->mmap_sem);
+        npages = get_user_pages(current, current->mm, user_addr, npages, write,
+                                0, req->pages, NULL);
+        up_read(&current->mm->mmap_sem);
+        if (npages < 0)
+                return npages;
+
+        req->num_pages = npages;
+        req->page_offset = offset;
+        return 0;
+}
+
+static ssize_t fuse_direct_io(struct file *file, const char __user *buf,
+                              size_t count, loff_t *ppos, int write)
+{
+        struct inode *inode = file->f_dentry->d_inode;
+        struct fuse_conn *fc = get_fuse_conn(inode);
+        size_t nmax = write ? fc->max_write : fc->max_read;
+        loff_t pos = *ppos;
+        ssize_t res = 0;
+        struct fuse_req *req = fuse_get_request(fc);
+        if (!req)
+                return -EINTR;
+
+        while (count) {
+                size_t tmp;
+                size_t nres;
+                size_t nbytes = min(count, nmax);
+                int err = fuse_get_user_pages(req, buf, nbytes, !write);
+                if (err) {
+                        res = err;
+                        break;
+                }
+                tmp = (req->num_pages << PAGE_SHIFT) - req->page_offset;
+                nbytes = min(nbytes, tmp);
+                if (write)
+                        nres = fuse_send_write(req, file, inode, pos, nbytes);
+                else
+                        nres = fuse_send_read(req, file, inode, pos, nbytes);
+                fuse_release_user_pages(req, !write);
+                if (req->out.h.error) {
+                        if (!res)
+                                res = req->out.h.error;
+                        break;
+                } else if (nres > nbytes) {
+                        res = -EIO;
+                        break;
+                }
+                count -= nres;
+                res += nres;
+                pos += nres;
+                buf += nres;
+                if (nres != nbytes)
+                        break;
+                if (count)
+                        fuse_reset_request(req);
+        }
+        fuse_put_request(fc, req);
+        if (res > 0) {
+                if (write && pos > i_size_read(inode))
+                        i_size_write(inode, pos);
+                *ppos = pos;
+        }
+        fuse_invalidate_attr(inode);
+
+        return res;
+}
+
+static ssize_t fuse_direct_read(struct file *file, char __user *buf,
+                                     size_t count, loff_t *ppos)
+{
+        return fuse_direct_io(file, buf, count, ppos, 0);
+}
+
+static ssize_t fuse_direct_write(struct file *file, const char __user *buf,
+                                 size_t count, loff_t *ppos)
+{
+        struct inode *inode = file->f_dentry->d_inode;
+        ssize_t res;
+        /* Don't allow parallel writes to the same file */
+        down(&inode->i_sem);
+        res = fuse_direct_io(file, buf, count, ppos, 1);
+        up(&inode->i_sem);
+        return res;
+}
+
+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 file_operations fuse_direct_io_file_operations = {
+        .llseek         = generic_file_llseek,
+        .read           = fuse_direct_read,
+        .write          = fuse_direct_write,
+        .open           = fuse_open,
+        .flush          = fuse_flush,
+        .release        = fuse_release,
+        .fsync          = fuse_fsync,
+        /* no mmap and sendfile */
+};
+
+static struct address_space_operations fuse_file_aops  = {
+        .readpage       = fuse_readpage,
+        .prepare_write  = fuse_prepare_write,
+        .commit_write   = fuse_commit_write,
+        .readpages      = fuse_readpages,
+        .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;
+}