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-rw-r--r--fs/fuse/file.c555
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;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-21 22:05:24 +0000