3217 lines
79 KiB
C
3217 lines
79 KiB
C
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/*
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FUSE: Filesystem in Userspace
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Copyright (C) 2001-2008 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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#include <linux/sched.h>
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#include <linux/sched/signal.h>
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#include <linux/module.h>
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#include <linux/swap.h>
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#include <linux/falloc.h>
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#include <linux/uio.h>
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#include <linux/fs.h>
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static int fuse_send_open(struct fuse_mount *fm, u64 nodeid,
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unsigned int open_flags, int opcode,
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struct fuse_open_out *outargp)
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{
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struct fuse_open_in inarg;
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FUSE_ARGS(args);
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memset(&inarg, 0, sizeof(inarg));
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inarg.flags = open_flags & ~(O_CREAT | O_EXCL | O_NOCTTY);
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if (!fm->fc->atomic_o_trunc)
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inarg.flags &= ~O_TRUNC;
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if (fm->fc->handle_killpriv_v2 &&
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(inarg.flags & O_TRUNC) && !capable(CAP_FSETID)) {
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inarg.open_flags |= FUSE_OPEN_KILL_SUIDGID;
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}
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args.opcode = opcode;
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args.nodeid = nodeid;
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args.in_numargs = 1;
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args.in_args[0].size = sizeof(inarg);
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args.in_args[0].value = &inarg;
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args.out_numargs = 1;
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args.out_args[0].size = sizeof(*outargp);
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args.out_args[0].value = outargp;
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return fuse_simple_request(fm, &args);
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}
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struct fuse_release_args {
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struct fuse_args args;
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struct fuse_release_in inarg;
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struct inode *inode;
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};
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struct fuse_file *fuse_file_alloc(struct fuse_mount *fm)
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{
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struct fuse_file *ff;
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ff = kzalloc(sizeof(struct fuse_file), GFP_KERNEL_ACCOUNT);
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if (unlikely(!ff))
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return NULL;
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ff->fm = fm;
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ff->release_args = kzalloc(sizeof(*ff->release_args),
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GFP_KERNEL_ACCOUNT);
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if (!ff->release_args) {
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kfree(ff);
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return NULL;
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}
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INIT_LIST_HEAD(&ff->write_entry);
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mutex_init(&ff->readdir.lock);
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refcount_set(&ff->count, 1);
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RB_CLEAR_NODE(&ff->polled_node);
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init_waitqueue_head(&ff->poll_wait);
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ff->kh = atomic64_inc_return(&fm->fc->khctr);
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return ff;
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}
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void fuse_file_free(struct fuse_file *ff)
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{
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kfree(ff->release_args);
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mutex_destroy(&ff->readdir.lock);
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kfree(ff);
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}
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static struct fuse_file *fuse_file_get(struct fuse_file *ff)
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{
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refcount_inc(&ff->count);
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return ff;
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}
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static void fuse_release_end(struct fuse_mount *fm, struct fuse_args *args,
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int error)
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{
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struct fuse_release_args *ra = container_of(args, typeof(*ra), args);
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iput(ra->inode);
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kfree(ra);
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}
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static void fuse_file_put(struct fuse_file *ff, bool sync, bool isdir)
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{
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if (refcount_dec_and_test(&ff->count)) {
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struct fuse_args *args = &ff->release_args->args;
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if (isdir ? ff->fm->fc->no_opendir : ff->fm->fc->no_open) {
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/* Do nothing when client does not implement 'open' */
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fuse_release_end(ff->fm, args, 0);
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} else if (sync) {
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fuse_simple_request(ff->fm, args);
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fuse_release_end(ff->fm, args, 0);
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} else {
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args->end = fuse_release_end;
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if (fuse_simple_background(ff->fm, args,
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GFP_KERNEL | __GFP_NOFAIL))
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fuse_release_end(ff->fm, args, -ENOTCONN);
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}
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kfree(ff);
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}
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}
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struct fuse_file *fuse_file_open(struct fuse_mount *fm, u64 nodeid,
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unsigned int open_flags, bool isdir)
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{
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struct fuse_conn *fc = fm->fc;
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struct fuse_file *ff;
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int opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN;
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ff = fuse_file_alloc(fm);
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if (!ff)
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return ERR_PTR(-ENOMEM);
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ff->fh = 0;
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/* Default for no-open */
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ff->open_flags = FOPEN_KEEP_CACHE | (isdir ? FOPEN_CACHE_DIR : 0);
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if (isdir ? !fc->no_opendir : !fc->no_open) {
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struct fuse_open_out outarg;
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int err;
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err = fuse_send_open(fm, nodeid, open_flags, opcode, &outarg);
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if (!err) {
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ff->fh = outarg.fh;
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ff->open_flags = outarg.open_flags;
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} else if (err != -ENOSYS) {
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fuse_file_free(ff);
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return ERR_PTR(err);
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} else {
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if (isdir)
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fc->no_opendir = 1;
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else
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fc->no_open = 1;
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}
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}
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if (isdir)
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ff->open_flags &= ~FOPEN_DIRECT_IO;
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ff->nodeid = nodeid;
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return ff;
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}
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int fuse_do_open(struct fuse_mount *fm, u64 nodeid, struct file *file,
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bool isdir)
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{
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struct fuse_file *ff = fuse_file_open(fm, nodeid, file->f_flags, isdir);
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if (!IS_ERR(ff))
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file->private_data = ff;
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return PTR_ERR_OR_ZERO(ff);
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}
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EXPORT_SYMBOL_GPL(fuse_do_open);
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static void fuse_link_write_file(struct file *file)
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{
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struct inode *inode = file_inode(file);
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struct fuse_inode *fi = get_fuse_inode(inode);
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struct fuse_file *ff = file->private_data;
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/*
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* file may be written through mmap, so chain it onto the
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* inodes's write_file list
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*/
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spin_lock(&fi->lock);
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if (list_empty(&ff->write_entry))
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list_add(&ff->write_entry, &fi->write_files);
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spin_unlock(&fi->lock);
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}
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void fuse_finish_open(struct inode *inode, struct file *file)
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{
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struct fuse_file *ff = file->private_data;
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struct fuse_conn *fc = get_fuse_conn(inode);
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if (ff->open_flags & FOPEN_STREAM)
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stream_open(inode, file);
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else if (ff->open_flags & FOPEN_NONSEEKABLE)
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nonseekable_open(inode, file);
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if (fc->atomic_o_trunc && (file->f_flags & O_TRUNC)) {
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struct fuse_inode *fi = get_fuse_inode(inode);
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spin_lock(&fi->lock);
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fi->attr_version = atomic64_inc_return(&fc->attr_version);
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i_size_write(inode, 0);
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spin_unlock(&fi->lock);
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file_update_time(file);
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fuse_invalidate_attr_mask(inode, FUSE_STATX_MODSIZE);
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}
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if ((file->f_mode & FMODE_WRITE) && fc->writeback_cache)
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fuse_link_write_file(file);
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}
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int fuse_open_common(struct inode *inode, struct file *file, bool isdir)
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{
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struct fuse_mount *fm = get_fuse_mount(inode);
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struct fuse_conn *fc = fm->fc;
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int err;
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bool is_wb_truncate = (file->f_flags & O_TRUNC) &&
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fc->atomic_o_trunc &&
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fc->writeback_cache;
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bool dax_truncate = (file->f_flags & O_TRUNC) &&
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fc->atomic_o_trunc && FUSE_IS_DAX(inode);
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if (fuse_is_bad(inode))
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return -EIO;
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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 (is_wb_truncate || dax_truncate)
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inode_lock(inode);
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if (dax_truncate) {
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filemap_invalidate_lock(inode->i_mapping);
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err = fuse_dax_break_layouts(inode, 0, 0);
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if (err)
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goto out_inode_unlock;
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}
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if (is_wb_truncate || dax_truncate)
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fuse_set_nowrite(inode);
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err = fuse_do_open(fm, get_node_id(inode), file, isdir);
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if (!err)
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fuse_finish_open(inode, file);
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if (is_wb_truncate || dax_truncate)
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fuse_release_nowrite(inode);
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if (!err) {
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struct fuse_file *ff = file->private_data;
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if (fc->atomic_o_trunc && (file->f_flags & O_TRUNC))
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truncate_pagecache(inode, 0);
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else if (!(ff->open_flags & FOPEN_KEEP_CACHE))
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invalidate_inode_pages2(inode->i_mapping);
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}
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if (dax_truncate)
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filemap_invalidate_unlock(inode->i_mapping);
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out_inode_unlock:
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if (is_wb_truncate || dax_truncate)
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inode_unlock(inode);
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return err;
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}
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static void fuse_prepare_release(struct fuse_inode *fi, struct fuse_file *ff,
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unsigned int flags, int opcode)
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{
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struct fuse_conn *fc = ff->fm->fc;
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struct fuse_release_args *ra = ff->release_args;
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/* Inode is NULL on error path of fuse_create_open() */
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if (likely(fi)) {
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spin_lock(&fi->lock);
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list_del(&ff->write_entry);
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spin_unlock(&fi->lock);
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}
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spin_lock(&fc->lock);
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if (!RB_EMPTY_NODE(&ff->polled_node))
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rb_erase(&ff->polled_node, &fc->polled_files);
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spin_unlock(&fc->lock);
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wake_up_interruptible_all(&ff->poll_wait);
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ra->inarg.fh = ff->fh;
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ra->inarg.flags = flags;
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ra->args.in_numargs = 1;
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ra->args.in_args[0].size = sizeof(struct fuse_release_in);
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ra->args.in_args[0].value = &ra->inarg;
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ra->args.opcode = opcode;
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ra->args.nodeid = ff->nodeid;
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ra->args.force = true;
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ra->args.nocreds = true;
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}
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void fuse_file_release(struct inode *inode, struct fuse_file *ff,
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unsigned int open_flags, fl_owner_t id, bool isdir)
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{
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struct fuse_inode *fi = get_fuse_inode(inode);
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struct fuse_release_args *ra = ff->release_args;
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int opcode = isdir ? FUSE_RELEASEDIR : FUSE_RELEASE;
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fuse_prepare_release(fi, ff, open_flags, opcode);
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if (ff->flock) {
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ra->inarg.release_flags |= FUSE_RELEASE_FLOCK_UNLOCK;
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ra->inarg.lock_owner = fuse_lock_owner_id(ff->fm->fc, id);
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}
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/* Hold inode until release is finished */
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ra->inode = igrab(inode);
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/*
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* Normally this will send the RELEASE request, however if
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* some asynchronous READ or WRITE requests are outstanding,
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* the sending will be delayed.
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*
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* Make the release synchronous if this is a fuseblk mount,
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* synchronous RELEASE is allowed (and desirable) in this case
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* because the server can be trusted not to screw up.
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*/
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fuse_file_put(ff, ff->fm->fc->destroy, isdir);
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}
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void fuse_release_common(struct file *file, bool isdir)
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{
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fuse_file_release(file_inode(file), file->private_data, file->f_flags,
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(fl_owner_t) file, isdir);
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}
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static int fuse_open(struct inode *inode, struct file *file)
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{
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return fuse_open_common(inode, file, false);
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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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/*
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* Dirty pages might remain despite write_inode_now() call from
|
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* fuse_flush() due to writes racing with the close.
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*/
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if (fc->writeback_cache)
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write_inode_now(inode, 1);
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fuse_release_common(file, false);
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/* return value is ignored by VFS */
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return 0;
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}
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|
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void fuse_sync_release(struct fuse_inode *fi, struct fuse_file *ff,
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unsigned int flags)
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{
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WARN_ON(refcount_read(&ff->count) > 1);
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fuse_prepare_release(fi, ff, flags, FUSE_RELEASE);
|
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/*
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* iput(NULL) is a no-op and since the refcount is 1 and everything's
|
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* synchronous, we are fine with not doing igrab() here"
|
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*/
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fuse_file_put(ff, true, false);
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}
|
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EXPORT_SYMBOL_GPL(fuse_sync_release);
|
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|
|
||
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/*
|
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* Scramble the ID space with XTEA, so that the value of the files_struct
|
||
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* pointer is not exposed to userspace.
|
||
|
*/
|
||
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u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id)
|
||
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{
|
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u32 *k = fc->scramble_key;
|
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u64 v = (unsigned long) id;
|
||
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u32 v0 = v;
|
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u32 v1 = v >> 32;
|
||
|
u32 sum = 0;
|
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|
int i;
|
||
|
|
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for (i = 0; i < 32; i++) {
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v0 += ((v1 << 4 ^ v1 >> 5) + v1) ^ (sum + k[sum & 3]);
|
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|
sum += 0x9E3779B9;
|
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|
v1 += ((v0 << 4 ^ v0 >> 5) + v0) ^ (sum + k[sum>>11 & 3]);
|
||
|
}
|
||
|
|
||
|
return (u64) v0 + ((u64) v1 << 32);
|
||
|
}
|
||
|
|
||
|
struct fuse_writepage_args {
|
||
|
struct fuse_io_args ia;
|
||
|
struct rb_node writepages_entry;
|
||
|
struct list_head queue_entry;
|
||
|
struct fuse_writepage_args *next;
|
||
|
struct inode *inode;
|
||
|
struct fuse_sync_bucket *bucket;
|
||
|
};
|
||
|
|
||
|
static struct fuse_writepage_args *fuse_find_writeback(struct fuse_inode *fi,
|
||
|
pgoff_t idx_from, pgoff_t idx_to)
|
||
|
{
|
||
|
struct rb_node *n;
|
||
|
|
||
|
n = fi->writepages.rb_node;
|
||
|
|
||
|
while (n) {
|
||
|
struct fuse_writepage_args *wpa;
|
||
|
pgoff_t curr_index;
|
||
|
|
||
|
wpa = rb_entry(n, struct fuse_writepage_args, writepages_entry);
|
||
|
WARN_ON(get_fuse_inode(wpa->inode) != fi);
|
||
|
curr_index = wpa->ia.write.in.offset >> PAGE_SHIFT;
|
||
|
if (idx_from >= curr_index + wpa->ia.ap.num_pages)
|
||
|
n = n->rb_right;
|
||
|
else if (idx_to < curr_index)
|
||
|
n = n->rb_left;
|
||
|
else
|
||
|
return wpa;
|
||
|
}
|
||
|
return NULL;
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* Check if any page in a range is under writeback
|
||
|
*
|
||
|
* This is currently done by walking the list of writepage requests
|
||
|
* for the inode, which can be pretty inefficient.
|
||
|
*/
|
||
|
static bool fuse_range_is_writeback(struct inode *inode, pgoff_t idx_from,
|
||
|
pgoff_t idx_to)
|
||
|
{
|
||
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
||
|
bool found;
|
||
|
|
||
|
spin_lock(&fi->lock);
|
||
|
found = fuse_find_writeback(fi, idx_from, idx_to);
|
||
|
spin_unlock(&fi->lock);
|
||
|
|
||
|
return found;
|
||
|
}
|
||
|
|
||
|
static inline bool fuse_page_is_writeback(struct inode *inode, pgoff_t index)
|
||
|
{
|
||
|
return fuse_range_is_writeback(inode, index, index);
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* Wait for page writeback to be completed.
|
||
|
*
|
||
|
* Since fuse doesn't rely on the VM writeback tracking, this has to
|
||
|
* use some other means.
|
||
|
*/
|
||
|
static void fuse_wait_on_page_writeback(struct inode *inode, pgoff_t index)
|
||
|
{
|
||
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
||
|
|
||
|
wait_event(fi->page_waitq, !fuse_page_is_writeback(inode, index));
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* Wait for all pending writepages on the inode to finish.
|
||
|
*
|
||
|
* This is currently done by blocking further writes with FUSE_NOWRITE
|
||
|
* and waiting for all sent writes to complete.
|
||
|
*
|
||
|
* This must be called under i_mutex, otherwise the FUSE_NOWRITE usage
|
||
|
* could conflict with truncation.
|
||
|
*/
|
||
|
static void fuse_sync_writes(struct inode *inode)
|
||
|
{
|
||
|
fuse_set_nowrite(inode);
|
||
|
fuse_release_nowrite(inode);
|
||
|
}
|
||
|
|
||
|
static int fuse_flush(struct file *file, fl_owner_t id)
|
||
|
{
|
||
|
struct inode *inode = file_inode(file);
|
||
|
struct fuse_mount *fm = get_fuse_mount(inode);
|
||
|
struct fuse_file *ff = file->private_data;
|
||
|
struct fuse_flush_in inarg;
|
||
|
FUSE_ARGS(args);
|
||
|
int err;
|
||
|
|
||
|
if (fuse_is_bad(inode))
|
||
|
return -EIO;
|
||
|
|
||
|
if (ff->open_flags & FOPEN_NOFLUSH && !fm->fc->writeback_cache)
|
||
|
return 0;
|
||
|
|
||
|
err = write_inode_now(inode, 1);
|
||
|
if (err)
|
||
|
return err;
|
||
|
|
||
|
inode_lock(inode);
|
||
|
fuse_sync_writes(inode);
|
||
|
inode_unlock(inode);
|
||
|
|
||
|
err = filemap_check_errors(file->f_mapping);
|
||
|
if (err)
|
||
|
return err;
|
||
|
|
||
|
err = 0;
|
||
|
if (fm->fc->no_flush)
|
||
|
goto inval_attr_out;
|
||
|
|
||
|
memset(&inarg, 0, sizeof(inarg));
|
||
|
inarg.fh = ff->fh;
|
||
|
inarg.lock_owner = fuse_lock_owner_id(fm->fc, id);
|
||
|
args.opcode = FUSE_FLUSH;
|
||
|
args.nodeid = get_node_id(inode);
|
||
|
args.in_numargs = 1;
|
||
|
args.in_args[0].size = sizeof(inarg);
|
||
|
args.in_args[0].value = &inarg;
|
||
|
args.force = true;
|
||
|
|
||
|
err = fuse_simple_request(fm, &args);
|
||
|
if (err == -ENOSYS) {
|
||
|
fm->fc->no_flush = 1;
|
||
|
err = 0;
|
||
|
}
|
||
|
|
||
|
inval_attr_out:
|
||
|
/*
|
||
|
* In memory i_blocks is not maintained by fuse, if writeback cache is
|
||
|
* enabled, i_blocks from cached attr may not be accurate.
|
||
|
*/
|
||
|
if (!err && fm->fc->writeback_cache)
|
||
|
fuse_invalidate_attr_mask(inode, STATX_BLOCKS);
|
||
|
return err;
|
||
|
}
|
||
|
|
||
|
int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
|
||
|
int datasync, int opcode)
|
||
|
{
|
||
|
struct inode *inode = file->f_mapping->host;
|
||
|
struct fuse_mount *fm = get_fuse_mount(inode);
|
||
|
struct fuse_file *ff = file->private_data;
|
||
|
FUSE_ARGS(args);
|
||
|
struct fuse_fsync_in inarg;
|
||
|
|
||
|
memset(&inarg, 0, sizeof(inarg));
|
||
|
inarg.fh = ff->fh;
|
||
|
inarg.fsync_flags = datasync ? FUSE_FSYNC_FDATASYNC : 0;
|
||
|
args.opcode = opcode;
|
||
|
args.nodeid = get_node_id(inode);
|
||
|
args.in_numargs = 1;
|
||
|
args.in_args[0].size = sizeof(inarg);
|
||
|
args.in_args[0].value = &inarg;
|
||
|
return fuse_simple_request(fm, &args);
|
||
|
}
|
||
|
|
||
|
static int fuse_fsync(struct file *file, loff_t start, loff_t end,
|
||
|
int datasync)
|
||
|
{
|
||
|
struct inode *inode = file->f_mapping->host;
|
||
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
||
|
int err;
|
||
|
|
||
|
if (fuse_is_bad(inode))
|
||
|
return -EIO;
|
||
|
|
||
|
inode_lock(inode);
|
||
|
|
||
|
/*
|
||
|
* Start writeback against all dirty pages of the inode, then
|
||
|
* wait for all outstanding writes, before sending the FSYNC
|
||
|
* request.
|
||
|
*/
|
||
|
err = file_write_and_wait_range(file, start, end);
|
||
|
if (err)
|
||
|
goto out;
|
||
|
|
||
|
fuse_sync_writes(inode);
|
||
|
|
||
|
/*
|
||
|
* Due to implementation of fuse writeback
|
||
|
* file_write_and_wait_range() does not catch errors.
|
||
|
* We have to do this directly after fuse_sync_writes()
|
||
|
*/
|
||
|
err = file_check_and_advance_wb_err(file);
|
||
|
if (err)
|
||
|
goto out;
|
||
|
|
||
|
err = sync_inode_metadata(inode, 1);
|
||
|
if (err)
|
||
|
goto out;
|
||
|
|
||
|
if (fc->no_fsync)
|
||
|
goto out;
|
||
|
|
||
|
err = fuse_fsync_common(file, start, end, datasync, FUSE_FSYNC);
|
||
|
if (err == -ENOSYS) {
|
||
|
fc->no_fsync = 1;
|
||
|
err = 0;
|
||
|
}
|
||
|
out:
|
||
|
inode_unlock(inode);
|
||
|
|
||
|
return err;
|
||
|
}
|
||
|
|
||
|
void fuse_read_args_fill(struct fuse_io_args *ia, struct file *file, loff_t pos,
|
||
|
size_t count, int opcode)
|
||
|
{
|
||
|
struct fuse_file *ff = file->private_data;
|
||
|
struct fuse_args *args = &ia->ap.args;
|
||
|
|
||
|
ia->read.in.fh = ff->fh;
|
||
|
ia->read.in.offset = pos;
|
||
|
ia->read.in.size = count;
|
||
|
ia->read.in.flags = file->f_flags;
|
||
|
args->opcode = opcode;
|
||
|
args->nodeid = ff->nodeid;
|
||
|
args->in_numargs = 1;
|
||
|
args->in_args[0].size = sizeof(ia->read.in);
|
||
|
args->in_args[0].value = &ia->read.in;
|
||
|
args->out_argvar = true;
|
||
|
args->out_numargs = 1;
|
||
|
args->out_args[0].size = count;
|
||
|
}
|
||
|
|
||
|
static void fuse_release_user_pages(struct fuse_args_pages *ap,
|
||
|
bool should_dirty)
|
||
|
{
|
||
|
unsigned int i;
|
||
|
|
||
|
for (i = 0; i < ap->num_pages; i++) {
|
||
|
if (should_dirty)
|
||
|
set_page_dirty_lock(ap->pages[i]);
|
||
|
put_page(ap->pages[i]);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
static void fuse_io_release(struct kref *kref)
|
||
|
{
|
||
|
kfree(container_of(kref, struct fuse_io_priv, refcnt));
|
||
|
}
|
||
|
|
||
|
static ssize_t fuse_get_res_by_io(struct fuse_io_priv *io)
|
||
|
{
|
||
|
if (io->err)
|
||
|
return io->err;
|
||
|
|
||
|
if (io->bytes >= 0 && io->write)
|
||
|
return -EIO;
|
||
|
|
||
|
return io->bytes < 0 ? io->size : io->bytes;
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* In case of short read, the caller sets 'pos' to the position of
|
||
|
* actual end of fuse request in IO request. Otherwise, if bytes_requested
|
||
|
* == bytes_transferred or rw == WRITE, the caller sets 'pos' to -1.
|
||
|
*
|
||
|
* An example:
|
||
|
* User requested DIO read of 64K. It was split into two 32K fuse requests,
|
||
|
* both submitted asynchronously. The first of them was ACKed by userspace as
|
||
|
* fully completed (req->out.args[0].size == 32K) resulting in pos == -1. The
|
||
|
* second request was ACKed as short, e.g. only 1K was read, resulting in
|
||
|
* pos == 33K.
|
||
|
*
|
||
|
* Thus, when all fuse requests are completed, the minimal non-negative 'pos'
|
||
|
* will be equal to the length of the longest contiguous fragment of
|
||
|
* transferred data starting from the beginning of IO request.
|
||
|
*/
|
||
|
static void fuse_aio_complete(struct fuse_io_priv *io, int err, ssize_t pos)
|
||
|
{
|
||
|
int left;
|
||
|
|
||
|
spin_lock(&io->lock);
|
||
|
if (err)
|
||
|
io->err = io->err ? : err;
|
||
|
else if (pos >= 0 && (io->bytes < 0 || pos < io->bytes))
|
||
|
io->bytes = pos;
|
||
|
|
||
|
left = --io->reqs;
|
||
|
if (!left && io->blocking)
|
||
|
complete(io->done);
|
||
|
spin_unlock(&io->lock);
|
||
|
|
||
|
if (!left && !io->blocking) {
|
||
|
ssize_t res = fuse_get_res_by_io(io);
|
||
|
|
||
|
if (res >= 0) {
|
||
|
struct inode *inode = file_inode(io->iocb->ki_filp);
|
||
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
||
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
||
|
|
||
|
spin_lock(&fi->lock);
|
||
|
fi->attr_version = atomic64_inc_return(&fc->attr_version);
|
||
|
spin_unlock(&fi->lock);
|
||
|
}
|
||
|
|
||
|
io->iocb->ki_complete(io->iocb, res);
|
||
|
}
|
||
|
|
||
|
kref_put(&io->refcnt, fuse_io_release);
|
||
|
}
|
||
|
|
||
|
static struct fuse_io_args *fuse_io_alloc(struct fuse_io_priv *io,
|
||
|
unsigned int npages)
|
||
|
{
|
||
|
struct fuse_io_args *ia;
|
||
|
|
||
|
ia = kzalloc(sizeof(*ia), GFP_KERNEL);
|
||
|
if (ia) {
|
||
|
ia->io = io;
|
||
|
ia->ap.pages = fuse_pages_alloc(npages, GFP_KERNEL,
|
||
|
&ia->ap.descs);
|
||
|
if (!ia->ap.pages) {
|
||
|
kfree(ia);
|
||
|
ia = NULL;
|
||
|
}
|
||
|
}
|
||
|
return ia;
|
||
|
}
|
||
|
|
||
|
static void fuse_io_free(struct fuse_io_args *ia)
|
||
|
{
|
||
|
kfree(ia->ap.pages);
|
||
|
kfree(ia);
|
||
|
}
|
||
|
|
||
|
static void fuse_aio_complete_req(struct fuse_mount *fm, struct fuse_args *args,
|
||
|
int err)
|
||
|
{
|
||
|
struct fuse_io_args *ia = container_of(args, typeof(*ia), ap.args);
|
||
|
struct fuse_io_priv *io = ia->io;
|
||
|
ssize_t pos = -1;
|
||
|
|
||
|
fuse_release_user_pages(&ia->ap, io->should_dirty);
|
||
|
|
||
|
if (err) {
|
||
|
/* Nothing */
|
||
|
} else if (io->write) {
|
||
|
if (ia->write.out.size > ia->write.in.size) {
|
||
|
err = -EIO;
|
||
|
} else if (ia->write.in.size != ia->write.out.size) {
|
||
|
pos = ia->write.in.offset - io->offset +
|
||
|
ia->write.out.size;
|
||
|
}
|
||
|
} else {
|
||
|
u32 outsize = args->out_args[0].size;
|
||
|
|
||
|
if (ia->read.in.size != outsize)
|
||
|
pos = ia->read.in.offset - io->offset + outsize;
|
||
|
}
|
||
|
|
||
|
fuse_aio_complete(io, err, pos);
|
||
|
fuse_io_free(ia);
|
||
|
}
|
||
|
|
||
|
static ssize_t fuse_async_req_send(struct fuse_mount *fm,
|
||
|
struct fuse_io_args *ia, size_t num_bytes)
|
||
|
{
|
||
|
ssize_t err;
|
||
|
struct fuse_io_priv *io = ia->io;
|
||
|
|
||
|
spin_lock(&io->lock);
|
||
|
kref_get(&io->refcnt);
|
||
|
io->size += num_bytes;
|
||
|
io->reqs++;
|
||
|
spin_unlock(&io->lock);
|
||
|
|
||
|
ia->ap.args.end = fuse_aio_complete_req;
|
||
|
ia->ap.args.may_block = io->should_dirty;
|
||
|
err = fuse_simple_background(fm, &ia->ap.args, GFP_KERNEL);
|
||
|
if (err)
|
||
|
fuse_aio_complete_req(fm, &ia->ap.args, err);
|
||
|
|
||
|
return num_bytes;
|
||
|
}
|
||
|
|
||
|
static ssize_t fuse_send_read(struct fuse_io_args *ia, loff_t pos, size_t count,
|
||
|
fl_owner_t owner)
|
||
|
{
|
||
|
struct file *file = ia->io->iocb->ki_filp;
|
||
|
struct fuse_file *ff = file->private_data;
|
||
|
struct fuse_mount *fm = ff->fm;
|
||
|
|
||
|
fuse_read_args_fill(ia, file, pos, count, FUSE_READ);
|
||
|
if (owner != NULL) {
|
||
|
ia->read.in.read_flags |= FUSE_READ_LOCKOWNER;
|
||
|
ia->read.in.lock_owner = fuse_lock_owner_id(fm->fc, owner);
|
||
|
}
|
||
|
|
||
|
if (ia->io->async)
|
||
|
return fuse_async_req_send(fm, ia, count);
|
||
|
|
||
|
return fuse_simple_request(fm, &ia->ap.args);
|
||
|
}
|
||
|
|
||
|
static void fuse_read_update_size(struct inode *inode, loff_t size,
|
||
|
u64 attr_ver)
|
||
|
{
|
||
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
||
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
||
|
|
||
|
spin_lock(&fi->lock);
|
||
|
if (attr_ver >= fi->attr_version && size < inode->i_size &&
|
||
|
!test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) {
|
||
|
fi->attr_version = atomic64_inc_return(&fc->attr_version);
|
||
|
i_size_write(inode, size);
|
||
|
}
|
||
|
spin_unlock(&fi->lock);
|
||
|
}
|
||
|
|
||
|
static void fuse_short_read(struct inode *inode, u64 attr_ver, size_t num_read,
|
||
|
struct fuse_args_pages *ap)
|
||
|
{
|
||
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
||
|
|
||
|
/*
|
||
|
* If writeback_cache is enabled, a short read means there's a hole in
|
||
|
* the file. Some data after the hole is in page cache, but has not
|
||
|
* reached the client fs yet. So the hole is not present there.
|
||
|
*/
|
||
|
if (!fc->writeback_cache) {
|
||
|
loff_t pos = page_offset(ap->pages[0]) + num_read;
|
||
|
fuse_read_update_size(inode, pos, attr_ver);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
static int fuse_do_readpage(struct file *file, struct page *page)
|
||
|
{
|
||
|
struct inode *inode = page->mapping->host;
|
||
|
struct fuse_mount *fm = get_fuse_mount(inode);
|
||
|
loff_t pos = page_offset(page);
|
||
|
struct fuse_page_desc desc = { .length = PAGE_SIZE };
|
||
|
struct fuse_io_args ia = {
|
||
|
.ap.args.page_zeroing = true,
|
||
|
.ap.args.out_pages = true,
|
||
|
.ap.num_pages = 1,
|
||
|
.ap.pages = &page,
|
||
|
.ap.descs = &desc,
|
||
|
};
|
||
|
ssize_t res;
|
||
|
u64 attr_ver;
|
||
|
|
||
|
/*
|
||
|
* Page writeback can extend beyond the lifetime of the
|
||
|
* page-cache page, so make sure we read a properly synced
|
||
|
* page.
|
||
|
*/
|
||
|
fuse_wait_on_page_writeback(inode, page->index);
|
||
|
|
||
|
attr_ver = fuse_get_attr_version(fm->fc);
|
||
|
|
||
|
/* Don't overflow end offset */
|
||
|
if (pos + (desc.length - 1) == LLONG_MAX)
|
||
|
desc.length--;
|
||
|
|
||
|
fuse_read_args_fill(&ia, file, pos, desc.length, FUSE_READ);
|
||
|
res = fuse_simple_request(fm, &ia.ap.args);
|
||
|
if (res < 0)
|
||
|
return res;
|
||
|
/*
|
||
|
* Short read means EOF. If file size is larger, truncate it
|
||
|
*/
|
||
|
if (res < desc.length)
|
||
|
fuse_short_read(inode, attr_ver, res, &ia.ap);
|
||
|
|
||
|
SetPageUptodate(page);
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static int fuse_read_folio(struct file *file, struct folio *folio)
|
||
|
{
|
||
|
struct page *page = &folio->page;
|
||
|
struct inode *inode = page->mapping->host;
|
||
|
int err;
|
||
|
|
||
|
err = -EIO;
|
||
|
if (fuse_is_bad(inode))
|
||
|
goto out;
|
||
|
|
||
|
err = fuse_do_readpage(file, page);
|
||
|
fuse_invalidate_atime(inode);
|
||
|
out:
|
||
|
unlock_page(page);
|
||
|
return err;
|
||
|
}
|
||
|
|
||
|
static void fuse_readpages_end(struct fuse_mount *fm, struct fuse_args *args,
|
||
|
int err)
|
||
|
{
|
||
|
int i;
|
||
|
struct fuse_io_args *ia = container_of(args, typeof(*ia), ap.args);
|
||
|
struct fuse_args_pages *ap = &ia->ap;
|
||
|
size_t count = ia->read.in.size;
|
||
|
size_t num_read = args->out_args[0].size;
|
||
|
struct address_space *mapping = NULL;
|
||
|
|
||
|
for (i = 0; mapping == NULL && i < ap->num_pages; i++)
|
||
|
mapping = ap->pages[i]->mapping;
|
||
|
|
||
|
if (mapping) {
|
||
|
struct inode *inode = mapping->host;
|
||
|
|
||
|
/*
|
||
|
* Short read means EOF. If file size is larger, truncate it
|
||
|
*/
|
||
|
if (!err && num_read < count)
|
||
|
fuse_short_read(inode, ia->read.attr_ver, num_read, ap);
|
||
|
|
||
|
fuse_invalidate_atime(inode);
|
||
|
}
|
||
|
|
||
|
for (i = 0; i < ap->num_pages; i++) {
|
||
|
struct page *page = ap->pages[i];
|
||
|
|
||
|
if (!err)
|
||
|
SetPageUptodate(page);
|
||
|
else
|
||
|
SetPageError(page);
|
||
|
unlock_page(page);
|
||
|
put_page(page);
|
||
|
}
|
||
|
if (ia->ff)
|
||
|
fuse_file_put(ia->ff, false, false);
|
||
|
|
||
|
fuse_io_free(ia);
|
||
|
}
|
||
|
|
||
|
static void fuse_send_readpages(struct fuse_io_args *ia, struct file *file)
|
||
|
{
|
||
|
struct fuse_file *ff = file->private_data;
|
||
|
struct fuse_mount *fm = ff->fm;
|
||
|
struct fuse_args_pages *ap = &ia->ap;
|
||
|
loff_t pos = page_offset(ap->pages[0]);
|
||
|
size_t count = ap->num_pages << PAGE_SHIFT;
|
||
|
ssize_t res;
|
||
|
int err;
|
||
|
|
||
|
ap->args.out_pages = true;
|
||
|
ap->args.page_zeroing = true;
|
||
|
ap->args.page_replace = true;
|
||
|
|
||
|
/* Don't overflow end offset */
|
||
|
if (pos + (count - 1) == LLONG_MAX) {
|
||
|
count--;
|
||
|
ap->descs[ap->num_pages - 1].length--;
|
||
|
}
|
||
|
WARN_ON((loff_t) (pos + count) < 0);
|
||
|
|
||
|
fuse_read_args_fill(ia, file, pos, count, FUSE_READ);
|
||
|
ia->read.attr_ver = fuse_get_attr_version(fm->fc);
|
||
|
if (fm->fc->async_read) {
|
||
|
ia->ff = fuse_file_get(ff);
|
||
|
ap->args.end = fuse_readpages_end;
|
||
|
err = fuse_simple_background(fm, &ap->args, GFP_KERNEL);
|
||
|
if (!err)
|
||
|
return;
|
||
|
} else {
|
||
|
res = fuse_simple_request(fm, &ap->args);
|
||
|
err = res < 0 ? res : 0;
|
||
|
}
|
||
|
fuse_readpages_end(fm, &ap->args, err);
|
||
|
}
|
||
|
|
||
|
static void fuse_readahead(struct readahead_control *rac)
|
||
|
{
|
||
|
struct inode *inode = rac->mapping->host;
|
||
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
||
|
unsigned int i, max_pages, nr_pages = 0;
|
||
|
|
||
|
if (fuse_is_bad(inode))
|
||
|
return;
|
||
|
|
||
|
max_pages = min_t(unsigned int, fc->max_pages,
|
||
|
fc->max_read / PAGE_SIZE);
|
||
|
|
||
|
for (;;) {
|
||
|
struct fuse_io_args *ia;
|
||
|
struct fuse_args_pages *ap;
|
||
|
|
||
|
if (fc->num_background >= fc->congestion_threshold &&
|
||
|
rac->ra->async_size >= readahead_count(rac))
|
||
|
/*
|
||
|
* Congested and only async pages left, so skip the
|
||
|
* rest.
|
||
|
*/
|
||
|
break;
|
||
|
|
||
|
nr_pages = readahead_count(rac) - nr_pages;
|
||
|
if (nr_pages > max_pages)
|
||
|
nr_pages = max_pages;
|
||
|
if (nr_pages == 0)
|
||
|
break;
|
||
|
ia = fuse_io_alloc(NULL, nr_pages);
|
||
|
if (!ia)
|
||
|
return;
|
||
|
ap = &ia->ap;
|
||
|
nr_pages = __readahead_batch(rac, ap->pages, nr_pages);
|
||
|
for (i = 0; i < nr_pages; i++) {
|
||
|
fuse_wait_on_page_writeback(inode,
|
||
|
readahead_index(rac) + i);
|
||
|
ap->descs[i].length = PAGE_SIZE;
|
||
|
}
|
||
|
ap->num_pages = nr_pages;
|
||
|
fuse_send_readpages(ia, rac->file);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
static ssize_t fuse_cache_read_iter(struct kiocb *iocb, struct iov_iter *to)
|
||
|
{
|
||
|
struct inode *inode = iocb->ki_filp->f_mapping->host;
|
||
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
||
|
|
||
|
/*
|
||
|
* In auto invalidate mode, always update attributes on read.
|
||
|
* Otherwise, only update if we attempt to read past EOF (to ensure
|
||
|
* i_size is up to date).
|
||
|
*/
|
||
|
if (fc->auto_inval_data ||
|
||
|
(iocb->ki_pos + iov_iter_count(to) > i_size_read(inode))) {
|
||
|
int err;
|
||
|
err = fuse_update_attributes(inode, iocb->ki_filp, STATX_SIZE);
|
||
|
if (err)
|
||
|
return err;
|
||
|
}
|
||
|
|
||
|
return generic_file_read_iter(iocb, to);
|
||
|
}
|
||
|
|
||
|
static void fuse_write_args_fill(struct fuse_io_args *ia, struct fuse_file *ff,
|
||
|
loff_t pos, size_t count)
|
||
|
{
|
||
|
struct fuse_args *args = &ia->ap.args;
|
||
|
|
||
|
ia->write.in.fh = ff->fh;
|
||
|
ia->write.in.offset = pos;
|
||
|
ia->write.in.size = count;
|
||
|
args->opcode = FUSE_WRITE;
|
||
|
args->nodeid = ff->nodeid;
|
||
|
args->in_numargs = 2;
|
||
|
if (ff->fm->fc->minor < 9)
|
||
|
args->in_args[0].size = FUSE_COMPAT_WRITE_IN_SIZE;
|
||
|
else
|
||
|
args->in_args[0].size = sizeof(ia->write.in);
|
||
|
args->in_args[0].value = &ia->write.in;
|
||
|
args->in_args[1].size = count;
|
||
|
args->out_numargs = 1;
|
||
|
args->out_args[0].size = sizeof(ia->write.out);
|
||
|
args->out_args[0].value = &ia->write.out;
|
||
|
}
|
||
|
|
||
|
static unsigned int fuse_write_flags(struct kiocb *iocb)
|
||
|
{
|
||
|
unsigned int flags = iocb->ki_filp->f_flags;
|
||
|
|
||
|
if (iocb_is_dsync(iocb))
|
||
|
flags |= O_DSYNC;
|
||
|
if (iocb->ki_flags & IOCB_SYNC)
|
||
|
flags |= O_SYNC;
|
||
|
|
||
|
return flags;
|
||
|
}
|
||
|
|
||
|
static ssize_t fuse_send_write(struct fuse_io_args *ia, loff_t pos,
|
||
|
size_t count, fl_owner_t owner)
|
||
|
{
|
||
|
struct kiocb *iocb = ia->io->iocb;
|
||
|
struct file *file = iocb->ki_filp;
|
||
|
struct fuse_file *ff = file->private_data;
|
||
|
struct fuse_mount *fm = ff->fm;
|
||
|
struct fuse_write_in *inarg = &ia->write.in;
|
||
|
ssize_t err;
|
||
|
|
||
|
fuse_write_args_fill(ia, ff, pos, count);
|
||
|
inarg->flags = fuse_write_flags(iocb);
|
||
|
if (owner != NULL) {
|
||
|
inarg->write_flags |= FUSE_WRITE_LOCKOWNER;
|
||
|
inarg->lock_owner = fuse_lock_owner_id(fm->fc, owner);
|
||
|
}
|
||
|
|
||
|
if (ia->io->async)
|
||
|
return fuse_async_req_send(fm, ia, count);
|
||
|
|
||
|
err = fuse_simple_request(fm, &ia->ap.args);
|
||
|
if (!err && ia->write.out.size > count)
|
||
|
err = -EIO;
|
||
|
|
||
|
return err ?: ia->write.out.size;
|
||
|
}
|
||
|
|
||
|
bool fuse_write_update_attr(struct inode *inode, loff_t pos, ssize_t written)
|
||
|
{
|
||
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
||
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
||
|
bool ret = false;
|
||
|
|
||
|
spin_lock(&fi->lock);
|
||
|
fi->attr_version = atomic64_inc_return(&fc->attr_version);
|
||
|
if (written > 0 && pos > inode->i_size) {
|
||
|
i_size_write(inode, pos);
|
||
|
ret = true;
|
||
|
}
|
||
|
spin_unlock(&fi->lock);
|
||
|
|
||
|
fuse_invalidate_attr_mask(inode, FUSE_STATX_MODSIZE);
|
||
|
|
||
|
return ret;
|
||
|
}
|
||
|
|
||
|
static ssize_t fuse_send_write_pages(struct fuse_io_args *ia,
|
||
|
struct kiocb *iocb, struct inode *inode,
|
||
|
loff_t pos, size_t count)
|
||
|
{
|
||
|
struct fuse_args_pages *ap = &ia->ap;
|
||
|
struct file *file = iocb->ki_filp;
|
||
|
struct fuse_file *ff = file->private_data;
|
||
|
struct fuse_mount *fm = ff->fm;
|
||
|
unsigned int offset, i;
|
||
|
bool short_write;
|
||
|
int err;
|
||
|
|
||
|
for (i = 0; i < ap->num_pages; i++)
|
||
|
fuse_wait_on_page_writeback(inode, ap->pages[i]->index);
|
||
|
|
||
|
fuse_write_args_fill(ia, ff, pos, count);
|
||
|
ia->write.in.flags = fuse_write_flags(iocb);
|
||
|
if (fm->fc->handle_killpriv_v2 && !capable(CAP_FSETID))
|
||
|
ia->write.in.write_flags |= FUSE_WRITE_KILL_SUIDGID;
|
||
|
|
||
|
err = fuse_simple_request(fm, &ap->args);
|
||
|
if (!err && ia->write.out.size > count)
|
||
|
err = -EIO;
|
||
|
|
||
|
short_write = ia->write.out.size < count;
|
||
|
offset = ap->descs[0].offset;
|
||
|
count = ia->write.out.size;
|
||
|
for (i = 0; i < ap->num_pages; i++) {
|
||
|
struct page *page = ap->pages[i];
|
||
|
|
||
|
if (err) {
|
||
|
ClearPageUptodate(page);
|
||
|
} else {
|
||
|
if (count >= PAGE_SIZE - offset)
|
||
|
count -= PAGE_SIZE - offset;
|
||
|
else {
|
||
|
if (short_write)
|
||
|
ClearPageUptodate(page);
|
||
|
count = 0;
|
||
|
}
|
||
|
offset = 0;
|
||
|
}
|
||
|
if (ia->write.page_locked && (i == ap->num_pages - 1))
|
||
|
unlock_page(page);
|
||
|
put_page(page);
|
||
|
}
|
||
|
|
||
|
return err;
|
||
|
}
|
||
|
|
||
|
static ssize_t fuse_fill_write_pages(struct fuse_io_args *ia,
|
||
|
struct address_space *mapping,
|
||
|
struct iov_iter *ii, loff_t pos,
|
||
|
unsigned int max_pages)
|
||
|
{
|
||
|
struct fuse_args_pages *ap = &ia->ap;
|
||
|
struct fuse_conn *fc = get_fuse_conn(mapping->host);
|
||
|
unsigned offset = pos & (PAGE_SIZE - 1);
|
||
|
size_t count = 0;
|
||
|
int err;
|
||
|
|
||
|
ap->args.in_pages = true;
|
||
|
ap->descs[0].offset = offset;
|
||
|
|
||
|
do {
|
||
|
size_t tmp;
|
||
|
struct page *page;
|
||
|
pgoff_t index = pos >> PAGE_SHIFT;
|
||
|
size_t bytes = min_t(size_t, PAGE_SIZE - offset,
|
||
|
iov_iter_count(ii));
|
||
|
|
||
|
bytes = min_t(size_t, bytes, fc->max_write - count);
|
||
|
|
||
|
again:
|
||
|
err = -EFAULT;
|
||
|
if (fault_in_iov_iter_readable(ii, bytes))
|
||
|
break;
|
||
|
|
||
|
err = -ENOMEM;
|
||
|
page = grab_cache_page_write_begin(mapping, index);
|
||
|
if (!page)
|
||
|
break;
|
||
|
|
||
|
if (mapping_writably_mapped(mapping))
|
||
|
flush_dcache_page(page);
|
||
|
|
||
|
tmp = copy_page_from_iter_atomic(page, offset, bytes, ii);
|
||
|
flush_dcache_page(page);
|
||
|
|
||
|
if (!tmp) {
|
||
|
unlock_page(page);
|
||
|
put_page(page);
|
||
|
goto again;
|
||
|
}
|
||
|
|
||
|
err = 0;
|
||
|
ap->pages[ap->num_pages] = page;
|
||
|
ap->descs[ap->num_pages].length = tmp;
|
||
|
ap->num_pages++;
|
||
|
|
||
|
count += tmp;
|
||
|
pos += tmp;
|
||
|
offset += tmp;
|
||
|
if (offset == PAGE_SIZE)
|
||
|
offset = 0;
|
||
|
|
||
|
/* If we copied full page, mark it uptodate */
|
||
|
if (tmp == PAGE_SIZE)
|
||
|
SetPageUptodate(page);
|
||
|
|
||
|
if (PageUptodate(page)) {
|
||
|
unlock_page(page);
|
||
|
} else {
|
||
|
ia->write.page_locked = true;
|
||
|
break;
|
||
|
}
|
||
|
if (!fc->big_writes)
|
||
|
break;
|
||
|
} while (iov_iter_count(ii) && count < fc->max_write &&
|
||
|
ap->num_pages < max_pages && offset == 0);
|
||
|
|
||
|
return count > 0 ? count : err;
|
||
|
}
|
||
|
|
||
|
static inline unsigned int fuse_wr_pages(loff_t pos, size_t len,
|
||
|
unsigned int max_pages)
|
||
|
{
|
||
|
return min_t(unsigned int,
|
||
|
((pos + len - 1) >> PAGE_SHIFT) -
|
||
|
(pos >> PAGE_SHIFT) + 1,
|
||
|
max_pages);
|
||
|
}
|
||
|
|
||
|
static ssize_t fuse_perform_write(struct kiocb *iocb,
|
||
|
struct address_space *mapping,
|
||
|
struct iov_iter *ii, loff_t pos)
|
||
|
{
|
||
|
struct inode *inode = mapping->host;
|
||
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
||
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
||
|
int err = 0;
|
||
|
ssize_t res = 0;
|
||
|
|
||
|
if (inode->i_size < pos + iov_iter_count(ii))
|
||
|
set_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
|
||
|
|
||
|
do {
|
||
|
ssize_t count;
|
||
|
struct fuse_io_args ia = {};
|
||
|
struct fuse_args_pages *ap = &ia.ap;
|
||
|
unsigned int nr_pages = fuse_wr_pages(pos, iov_iter_count(ii),
|
||
|
fc->max_pages);
|
||
|
|
||
|
ap->pages = fuse_pages_alloc(nr_pages, GFP_KERNEL, &ap->descs);
|
||
|
if (!ap->pages) {
|
||
|
err = -ENOMEM;
|
||
|
break;
|
||
|
}
|
||
|
|
||
|
count = fuse_fill_write_pages(&ia, mapping, ii, pos, nr_pages);
|
||
|
if (count <= 0) {
|
||
|
err = count;
|
||
|
} else {
|
||
|
err = fuse_send_write_pages(&ia, iocb, inode,
|
||
|
pos, count);
|
||
|
if (!err) {
|
||
|
size_t num_written = ia.write.out.size;
|
||
|
|
||
|
res += num_written;
|
||
|
pos += num_written;
|
||
|
|
||
|
/* break out of the loop on short write */
|
||
|
if (num_written != count)
|
||
|
err = -EIO;
|
||
|
}
|
||
|
}
|
||
|
kfree(ap->pages);
|
||
|
} while (!err && iov_iter_count(ii));
|
||
|
|
||
|
fuse_write_update_attr(inode, pos, res);
|
||
|
clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
|
||
|
|
||
|
return res > 0 ? res : err;
|
||
|
}
|
||
|
|
||
|
static ssize_t fuse_cache_write_iter(struct kiocb *iocb, struct iov_iter *from)
|
||
|
{
|
||
|
struct file *file = iocb->ki_filp;
|
||
|
struct address_space *mapping = file->f_mapping;
|
||
|
ssize_t written = 0;
|
||
|
ssize_t written_buffered = 0;
|
||
|
struct inode *inode = mapping->host;
|
||
|
ssize_t err;
|
||
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
||
|
loff_t endbyte = 0;
|
||
|
|
||
|
if (fc->writeback_cache) {
|
||
|
/* Update size (EOF optimization) and mode (SUID clearing) */
|
||
|
err = fuse_update_attributes(mapping->host, file,
|
||
|
STATX_SIZE | STATX_MODE);
|
||
|
if (err)
|
||
|
return err;
|
||
|
|
||
|
if (fc->handle_killpriv_v2 &&
|
||
|
setattr_should_drop_suidgid(&init_user_ns, file_inode(file))) {
|
||
|
goto writethrough;
|
||
|
}
|
||
|
|
||
|
return generic_file_write_iter(iocb, from);
|
||
|
}
|
||
|
|
||
|
writethrough:
|
||
|
inode_lock(inode);
|
||
|
|
||
|
/* We can write back this queue in page reclaim */
|
||
|
current->backing_dev_info = inode_to_bdi(inode);
|
||
|
|
||
|
err = generic_write_checks(iocb, from);
|
||
|
if (err <= 0)
|
||
|
goto out;
|
||
|
|
||
|
err = file_remove_privs(file);
|
||
|
if (err)
|
||
|
goto out;
|
||
|
|
||
|
err = file_update_time(file);
|
||
|
if (err)
|
||
|
goto out;
|
||
|
|
||
|
if (iocb->ki_flags & IOCB_DIRECT) {
|
||
|
loff_t pos = iocb->ki_pos;
|
||
|
written = generic_file_direct_write(iocb, from);
|
||
|
if (written < 0 || !iov_iter_count(from))
|
||
|
goto out;
|
||
|
|
||
|
pos += written;
|
||
|
|
||
|
written_buffered = fuse_perform_write(iocb, mapping, from, pos);
|
||
|
if (written_buffered < 0) {
|
||
|
err = written_buffered;
|
||
|
goto out;
|
||
|
}
|
||
|
endbyte = pos + written_buffered - 1;
|
||
|
|
||
|
err = filemap_write_and_wait_range(file->f_mapping, pos,
|
||
|
endbyte);
|
||
|
if (err)
|
||
|
goto out;
|
||
|
|
||
|
invalidate_mapping_pages(file->f_mapping,
|
||
|
pos >> PAGE_SHIFT,
|
||
|
endbyte >> PAGE_SHIFT);
|
||
|
|
||
|
written += written_buffered;
|
||
|
iocb->ki_pos = pos + written_buffered;
|
||
|
} else {
|
||
|
written = fuse_perform_write(iocb, mapping, from, iocb->ki_pos);
|
||
|
if (written >= 0)
|
||
|
iocb->ki_pos += written;
|
||
|
}
|
||
|
out:
|
||
|
current->backing_dev_info = NULL;
|
||
|
inode_unlock(inode);
|
||
|
if (written > 0)
|
||
|
written = generic_write_sync(iocb, written);
|
||
|
|
||
|
return written ? written : err;
|
||
|
}
|
||
|
|
||
|
static inline unsigned long fuse_get_user_addr(const struct iov_iter *ii)
|
||
|
{
|
||
|
return (unsigned long)ii->iov->iov_base + ii->iov_offset;
|
||
|
}
|
||
|
|
||
|
static inline size_t fuse_get_frag_size(const struct iov_iter *ii,
|
||
|
size_t max_size)
|
||
|
{
|
||
|
return min(iov_iter_single_seg_count(ii), max_size);
|
||
|
}
|
||
|
|
||
|
static int fuse_get_user_pages(struct fuse_args_pages *ap, struct iov_iter *ii,
|
||
|
size_t *nbytesp, int write,
|
||
|
unsigned int max_pages)
|
||
|
{
|
||
|
size_t nbytes = 0; /* # bytes already packed in req */
|
||
|
ssize_t ret = 0;
|
||
|
|
||
|
/* Special case for kernel I/O: can copy directly into the buffer */
|
||
|
if (iov_iter_is_kvec(ii)) {
|
||
|
unsigned long user_addr = fuse_get_user_addr(ii);
|
||
|
size_t frag_size = fuse_get_frag_size(ii, *nbytesp);
|
||
|
|
||
|
if (write)
|
||
|
ap->args.in_args[1].value = (void *) user_addr;
|
||
|
else
|
||
|
ap->args.out_args[0].value = (void *) user_addr;
|
||
|
|
||
|
iov_iter_advance(ii, frag_size);
|
||
|
*nbytesp = frag_size;
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
while (nbytes < *nbytesp && ap->num_pages < max_pages) {
|
||
|
unsigned npages;
|
||
|
size_t start;
|
||
|
ret = iov_iter_get_pages2(ii, &ap->pages[ap->num_pages],
|
||
|
*nbytesp - nbytes,
|
||
|
max_pages - ap->num_pages,
|
||
|
&start);
|
||
|
if (ret < 0)
|
||
|
break;
|
||
|
|
||
|
nbytes += ret;
|
||
|
|
||
|
ret += start;
|
||
|
npages = DIV_ROUND_UP(ret, PAGE_SIZE);
|
||
|
|
||
|
ap->descs[ap->num_pages].offset = start;
|
||
|
fuse_page_descs_length_init(ap->descs, ap->num_pages, npages);
|
||
|
|
||
|
ap->num_pages += npages;
|
||
|
ap->descs[ap->num_pages - 1].length -=
|
||
|
(PAGE_SIZE - ret) & (PAGE_SIZE - 1);
|
||
|
}
|
||
|
|
||
|
ap->args.user_pages = true;
|
||
|
if (write)
|
||
|
ap->args.in_pages = true;
|
||
|
else
|
||
|
ap->args.out_pages = true;
|
||
|
|
||
|
*nbytesp = nbytes;
|
||
|
|
||
|
return ret < 0 ? ret : 0;
|
||
|
}
|
||
|
|
||
|
ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
|
||
|
loff_t *ppos, int flags)
|
||
|
{
|
||
|
int write = flags & FUSE_DIO_WRITE;
|
||
|
int cuse = flags & FUSE_DIO_CUSE;
|
||
|
struct file *file = io->iocb->ki_filp;
|
||
|
struct inode *inode = file->f_mapping->host;
|
||
|
struct fuse_file *ff = file->private_data;
|
||
|
struct fuse_conn *fc = ff->fm->fc;
|
||
|
size_t nmax = write ? fc->max_write : fc->max_read;
|
||
|
loff_t pos = *ppos;
|
||
|
size_t count = iov_iter_count(iter);
|
||
|
pgoff_t idx_from = pos >> PAGE_SHIFT;
|
||
|
pgoff_t idx_to = (pos + count - 1) >> PAGE_SHIFT;
|
||
|
ssize_t res = 0;
|
||
|
int err = 0;
|
||
|
struct fuse_io_args *ia;
|
||
|
unsigned int max_pages;
|
||
|
|
||
|
max_pages = iov_iter_npages(iter, fc->max_pages);
|
||
|
ia = fuse_io_alloc(io, max_pages);
|
||
|
if (!ia)
|
||
|
return -ENOMEM;
|
||
|
|
||
|
if (!cuse && fuse_range_is_writeback(inode, idx_from, idx_to)) {
|
||
|
if (!write)
|
||
|
inode_lock(inode);
|
||
|
fuse_sync_writes(inode);
|
||
|
if (!write)
|
||
|
inode_unlock(inode);
|
||
|
}
|
||
|
|
||
|
io->should_dirty = !write && user_backed_iter(iter);
|
||
|
while (count) {
|
||
|
ssize_t nres;
|
||
|
fl_owner_t owner = current->files;
|
||
|
size_t nbytes = min(count, nmax);
|
||
|
|
||
|
err = fuse_get_user_pages(&ia->ap, iter, &nbytes, write,
|
||
|
max_pages);
|
||
|
if (err && !nbytes)
|
||
|
break;
|
||
|
|
||
|
if (write) {
|
||
|
if (!capable(CAP_FSETID))
|
||
|
ia->write.in.write_flags |= FUSE_WRITE_KILL_SUIDGID;
|
||
|
|
||
|
nres = fuse_send_write(ia, pos, nbytes, owner);
|
||
|
} else {
|
||
|
nres = fuse_send_read(ia, pos, nbytes, owner);
|
||
|
}
|
||
|
|
||
|
if (!io->async || nres < 0) {
|
||
|
fuse_release_user_pages(&ia->ap, io->should_dirty);
|
||
|
fuse_io_free(ia);
|
||
|
}
|
||
|
ia = NULL;
|
||
|
if (nres < 0) {
|
||
|
iov_iter_revert(iter, nbytes);
|
||
|
err = nres;
|
||
|
break;
|
||
|
}
|
||
|
WARN_ON(nres > nbytes);
|
||
|
|
||
|
count -= nres;
|
||
|
res += nres;
|
||
|
pos += nres;
|
||
|
if (nres != nbytes) {
|
||
|
iov_iter_revert(iter, nbytes - nres);
|
||
|
break;
|
||
|
}
|
||
|
if (count) {
|
||
|
max_pages = iov_iter_npages(iter, fc->max_pages);
|
||
|
ia = fuse_io_alloc(io, max_pages);
|
||
|
if (!ia)
|
||
|
break;
|
||
|
}
|
||
|
}
|
||
|
if (ia)
|
||
|
fuse_io_free(ia);
|
||
|
if (res > 0)
|
||
|
*ppos = pos;
|
||
|
|
||
|
return res > 0 ? res : err;
|
||
|
}
|
||
|
EXPORT_SYMBOL_GPL(fuse_direct_io);
|
||
|
|
||
|
static ssize_t __fuse_direct_read(struct fuse_io_priv *io,
|
||
|
struct iov_iter *iter,
|
||
|
loff_t *ppos)
|
||
|
{
|
||
|
ssize_t res;
|
||
|
struct inode *inode = file_inode(io->iocb->ki_filp);
|
||
|
|
||
|
res = fuse_direct_io(io, iter, ppos, 0);
|
||
|
|
||
|
fuse_invalidate_atime(inode);
|
||
|
|
||
|
return res;
|
||
|
}
|
||
|
|
||
|
static ssize_t fuse_direct_IO(struct kiocb *iocb, struct iov_iter *iter);
|
||
|
|
||
|
static ssize_t fuse_direct_read_iter(struct kiocb *iocb, struct iov_iter *to)
|
||
|
{
|
||
|
ssize_t res;
|
||
|
|
||
|
if (!is_sync_kiocb(iocb) && iocb->ki_flags & IOCB_DIRECT) {
|
||
|
res = fuse_direct_IO(iocb, to);
|
||
|
} else {
|
||
|
struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(iocb);
|
||
|
|
||
|
res = __fuse_direct_read(&io, to, &iocb->ki_pos);
|
||
|
}
|
||
|
|
||
|
return res;
|
||
|
}
|
||
|
|
||
|
static ssize_t fuse_direct_write_iter(struct kiocb *iocb, struct iov_iter *from)
|
||
|
{
|
||
|
struct inode *inode = file_inode(iocb->ki_filp);
|
||
|
struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(iocb);
|
||
|
ssize_t res;
|
||
|
|
||
|
/* Don't allow parallel writes to the same file */
|
||
|
inode_lock(inode);
|
||
|
res = generic_write_checks(iocb, from);
|
||
|
if (res > 0) {
|
||
|
if (!is_sync_kiocb(iocb) && iocb->ki_flags & IOCB_DIRECT) {
|
||
|
res = fuse_direct_IO(iocb, from);
|
||
|
} else {
|
||
|
res = fuse_direct_io(&io, from, &iocb->ki_pos,
|
||
|
FUSE_DIO_WRITE);
|
||
|
fuse_write_update_attr(inode, iocb->ki_pos, res);
|
||
|
}
|
||
|
}
|
||
|
inode_unlock(inode);
|
||
|
|
||
|
return res;
|
||
|
}
|
||
|
|
||
|
static ssize_t fuse_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
|
||
|
{
|
||
|
struct file *file = iocb->ki_filp;
|
||
|
struct fuse_file *ff = file->private_data;
|
||
|
struct inode *inode = file_inode(file);
|
||
|
|
||
|
if (fuse_is_bad(inode))
|
||
|
return -EIO;
|
||
|
|
||
|
if (FUSE_IS_DAX(inode))
|
||
|
return fuse_dax_read_iter(iocb, to);
|
||
|
|
||
|
if (!(ff->open_flags & FOPEN_DIRECT_IO))
|
||
|
return fuse_cache_read_iter(iocb, to);
|
||
|
else
|
||
|
return fuse_direct_read_iter(iocb, to);
|
||
|
}
|
||
|
|
||
|
static ssize_t fuse_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
|
||
|
{
|
||
|
struct file *file = iocb->ki_filp;
|
||
|
struct fuse_file *ff = file->private_data;
|
||
|
struct inode *inode = file_inode(file);
|
||
|
|
||
|
if (fuse_is_bad(inode))
|
||
|
return -EIO;
|
||
|
|
||
|
if (FUSE_IS_DAX(inode))
|
||
|
return fuse_dax_write_iter(iocb, from);
|
||
|
|
||
|
if (!(ff->open_flags & FOPEN_DIRECT_IO))
|
||
|
return fuse_cache_write_iter(iocb, from);
|
||
|
else
|
||
|
return fuse_direct_write_iter(iocb, from);
|
||
|
}
|
||
|
|
||
|
static void fuse_writepage_free(struct fuse_writepage_args *wpa)
|
||
|
{
|
||
|
struct fuse_args_pages *ap = &wpa->ia.ap;
|
||
|
int i;
|
||
|
|
||
|
if (wpa->bucket)
|
||
|
fuse_sync_bucket_dec(wpa->bucket);
|
||
|
|
||
|
for (i = 0; i < ap->num_pages; i++)
|
||
|
__free_page(ap->pages[i]);
|
||
|
|
||
|
if (wpa->ia.ff)
|
||
|
fuse_file_put(wpa->ia.ff, false, false);
|
||
|
|
||
|
kfree(ap->pages);
|
||
|
kfree(wpa);
|
||
|
}
|
||
|
|
||
|
static void fuse_writepage_finish(struct fuse_mount *fm,
|
||
|
struct fuse_writepage_args *wpa)
|
||
|
{
|
||
|
struct fuse_args_pages *ap = &wpa->ia.ap;
|
||
|
struct inode *inode = wpa->inode;
|
||
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
||
|
struct backing_dev_info *bdi = inode_to_bdi(inode);
|
||
|
int i;
|
||
|
|
||
|
for (i = 0; i < ap->num_pages; i++) {
|
||
|
dec_wb_stat(&bdi->wb, WB_WRITEBACK);
|
||
|
dec_node_page_state(ap->pages[i], NR_WRITEBACK_TEMP);
|
||
|
wb_writeout_inc(&bdi->wb);
|
||
|
}
|
||
|
wake_up(&fi->page_waitq);
|
||
|
}
|
||
|
|
||
|
/* Called under fi->lock, may release and reacquire it */
|
||
|
static void fuse_send_writepage(struct fuse_mount *fm,
|
||
|
struct fuse_writepage_args *wpa, loff_t size)
|
||
|
__releases(fi->lock)
|
||
|
__acquires(fi->lock)
|
||
|
{
|
||
|
struct fuse_writepage_args *aux, *next;
|
||
|
struct fuse_inode *fi = get_fuse_inode(wpa->inode);
|
||
|
struct fuse_write_in *inarg = &wpa->ia.write.in;
|
||
|
struct fuse_args *args = &wpa->ia.ap.args;
|
||
|
__u64 data_size = wpa->ia.ap.num_pages * PAGE_SIZE;
|
||
|
int err;
|
||
|
|
||
|
fi->writectr++;
|
||
|
if (inarg->offset + data_size <= size) {
|
||
|
inarg->size = data_size;
|
||
|
} else if (inarg->offset < size) {
|
||
|
inarg->size = size - inarg->offset;
|
||
|
} else {
|
||
|
/* Got truncated off completely */
|
||
|
goto out_free;
|
||
|
}
|
||
|
|
||
|
args->in_args[1].size = inarg->size;
|
||
|
args->force = true;
|
||
|
args->nocreds = true;
|
||
|
|
||
|
err = fuse_simple_background(fm, args, GFP_ATOMIC);
|
||
|
if (err == -ENOMEM) {
|
||
|
spin_unlock(&fi->lock);
|
||
|
err = fuse_simple_background(fm, args, GFP_NOFS | __GFP_NOFAIL);
|
||
|
spin_lock(&fi->lock);
|
||
|
}
|
||
|
|
||
|
/* Fails on broken connection only */
|
||
|
if (unlikely(err))
|
||
|
goto out_free;
|
||
|
|
||
|
return;
|
||
|
|
||
|
out_free:
|
||
|
fi->writectr--;
|
||
|
rb_erase(&wpa->writepages_entry, &fi->writepages);
|
||
|
fuse_writepage_finish(fm, wpa);
|
||
|
spin_unlock(&fi->lock);
|
||
|
|
||
|
/* After fuse_writepage_finish() aux request list is private */
|
||
|
for (aux = wpa->next; aux; aux = next) {
|
||
|
next = aux->next;
|
||
|
aux->next = NULL;
|
||
|
fuse_writepage_free(aux);
|
||
|
}
|
||
|
|
||
|
fuse_writepage_free(wpa);
|
||
|
spin_lock(&fi->lock);
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* If fi->writectr is positive (no truncate or fsync going on) send
|
||
|
* all queued writepage requests.
|
||
|
*
|
||
|
* Called with fi->lock
|
||
|
*/
|
||
|
void fuse_flush_writepages(struct inode *inode)
|
||
|
__releases(fi->lock)
|
||
|
__acquires(fi->lock)
|
||
|
{
|
||
|
struct fuse_mount *fm = get_fuse_mount(inode);
|
||
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
||
|
loff_t crop = i_size_read(inode);
|
||
|
struct fuse_writepage_args *wpa;
|
||
|
|
||
|
while (fi->writectr >= 0 && !list_empty(&fi->queued_writes)) {
|
||
|
wpa = list_entry(fi->queued_writes.next,
|
||
|
struct fuse_writepage_args, queue_entry);
|
||
|
list_del_init(&wpa->queue_entry);
|
||
|
fuse_send_writepage(fm, wpa, crop);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
static struct fuse_writepage_args *fuse_insert_writeback(struct rb_root *root,
|
||
|
struct fuse_writepage_args *wpa)
|
||
|
{
|
||
|
pgoff_t idx_from = wpa->ia.write.in.offset >> PAGE_SHIFT;
|
||
|
pgoff_t idx_to = idx_from + wpa->ia.ap.num_pages - 1;
|
||
|
struct rb_node **p = &root->rb_node;
|
||
|
struct rb_node *parent = NULL;
|
||
|
|
||
|
WARN_ON(!wpa->ia.ap.num_pages);
|
||
|
while (*p) {
|
||
|
struct fuse_writepage_args *curr;
|
||
|
pgoff_t curr_index;
|
||
|
|
||
|
parent = *p;
|
||
|
curr = rb_entry(parent, struct fuse_writepage_args,
|
||
|
writepages_entry);
|
||
|
WARN_ON(curr->inode != wpa->inode);
|
||
|
curr_index = curr->ia.write.in.offset >> PAGE_SHIFT;
|
||
|
|
||
|
if (idx_from >= curr_index + curr->ia.ap.num_pages)
|
||
|
p = &(*p)->rb_right;
|
||
|
else if (idx_to < curr_index)
|
||
|
p = &(*p)->rb_left;
|
||
|
else
|
||
|
return curr;
|
||
|
}
|
||
|
|
||
|
rb_link_node(&wpa->writepages_entry, parent, p);
|
||
|
rb_insert_color(&wpa->writepages_entry, root);
|
||
|
return NULL;
|
||
|
}
|
||
|
|
||
|
static void tree_insert(struct rb_root *root, struct fuse_writepage_args *wpa)
|
||
|
{
|
||
|
WARN_ON(fuse_insert_writeback(root, wpa));
|
||
|
}
|
||
|
|
||
|
static void fuse_writepage_end(struct fuse_mount *fm, struct fuse_args *args,
|
||
|
int error)
|
||
|
{
|
||
|
struct fuse_writepage_args *wpa =
|
||
|
container_of(args, typeof(*wpa), ia.ap.args);
|
||
|
struct inode *inode = wpa->inode;
|
||
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
||
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
||
|
|
||
|
mapping_set_error(inode->i_mapping, error);
|
||
|
/*
|
||
|
* A writeback finished and this might have updated mtime/ctime on
|
||
|
* server making local mtime/ctime stale. Hence invalidate attrs.
|
||
|
* Do this only if writeback_cache is not enabled. If writeback_cache
|
||
|
* is enabled, we trust local ctime/mtime.
|
||
|
*/
|
||
|
if (!fc->writeback_cache)
|
||
|
fuse_invalidate_attr_mask(inode, FUSE_STATX_MODIFY);
|
||
|
spin_lock(&fi->lock);
|
||
|
rb_erase(&wpa->writepages_entry, &fi->writepages);
|
||
|
while (wpa->next) {
|
||
|
struct fuse_mount *fm = get_fuse_mount(inode);
|
||
|
struct fuse_write_in *inarg = &wpa->ia.write.in;
|
||
|
struct fuse_writepage_args *next = wpa->next;
|
||
|
|
||
|
wpa->next = next->next;
|
||
|
next->next = NULL;
|
||
|
next->ia.ff = fuse_file_get(wpa->ia.ff);
|
||
|
tree_insert(&fi->writepages, next);
|
||
|
|
||
|
/*
|
||
|
* Skip fuse_flush_writepages() to make it easy to crop requests
|
||
|
* based on primary request size.
|
||
|
*
|
||
|
* 1st case (trivial): there are no concurrent activities using
|
||
|
* fuse_set/release_nowrite. Then we're on safe side because
|
||
|
* fuse_flush_writepages() would call fuse_send_writepage()
|
||
|
* anyway.
|
||
|
*
|
||
|
* 2nd case: someone called fuse_set_nowrite and it is waiting
|
||
|
* now for completion of all in-flight requests. This happens
|
||
|
* rarely and no more than once per page, so this should be
|
||
|
* okay.
|
||
|
*
|
||
|
* 3rd case: someone (e.g. fuse_do_setattr()) is in the middle
|
||
|
* of fuse_set_nowrite..fuse_release_nowrite section. The fact
|
||
|
* that fuse_set_nowrite returned implies that all in-flight
|
||
|
* requests were completed along with all of their secondary
|
||
|
* requests. Further primary requests are blocked by negative
|
||
|
* writectr. Hence there cannot be any in-flight requests and
|
||
|
* no invocations of fuse_writepage_end() while we're in
|
||
|
* fuse_set_nowrite..fuse_release_nowrite section.
|
||
|
*/
|
||
|
fuse_send_writepage(fm, next, inarg->offset + inarg->size);
|
||
|
}
|
||
|
fi->writectr--;
|
||
|
fuse_writepage_finish(fm, wpa);
|
||
|
spin_unlock(&fi->lock);
|
||
|
fuse_writepage_free(wpa);
|
||
|
}
|
||
|
|
||
|
static struct fuse_file *__fuse_write_file_get(struct fuse_inode *fi)
|
||
|
{
|
||
|
struct fuse_file *ff;
|
||
|
|
||
|
spin_lock(&fi->lock);
|
||
|
ff = list_first_entry_or_null(&fi->write_files, struct fuse_file,
|
||
|
write_entry);
|
||
|
if (ff)
|
||
|
fuse_file_get(ff);
|
||
|
spin_unlock(&fi->lock);
|
||
|
|
||
|
return ff;
|
||
|
}
|
||
|
|
||
|
static struct fuse_file *fuse_write_file_get(struct fuse_inode *fi)
|
||
|
{
|
||
|
struct fuse_file *ff = __fuse_write_file_get(fi);
|
||
|
WARN_ON(!ff);
|
||
|
return ff;
|
||
|
}
|
||
|
|
||
|
int fuse_write_inode(struct inode *inode, struct writeback_control *wbc)
|
||
|
{
|
||
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
||
|
struct fuse_file *ff;
|
||
|
int err;
|
||
|
|
||
|
/*
|
||
|
* Inode is always written before the last reference is dropped and
|
||
|
* hence this should not be reached from reclaim.
|
||
|
*
|
||
|
* Writing back the inode from reclaim can deadlock if the request
|
||
|
* processing itself needs an allocation. Allocations triggering
|
||
|
* reclaim while serving a request can't be prevented, because it can
|
||
|
* involve any number of unrelated userspace processes.
|
||
|
*/
|
||
|
WARN_ON(wbc->for_reclaim);
|
||
|
|
||
|
ff = __fuse_write_file_get(fi);
|
||
|
err = fuse_flush_times(inode, ff);
|
||
|
if (ff)
|
||
|
fuse_file_put(ff, false, false);
|
||
|
|
||
|
return err;
|
||
|
}
|
||
|
|
||
|
static struct fuse_writepage_args *fuse_writepage_args_alloc(void)
|
||
|
{
|
||
|
struct fuse_writepage_args *wpa;
|
||
|
struct fuse_args_pages *ap;
|
||
|
|
||
|
wpa = kzalloc(sizeof(*wpa), GFP_NOFS);
|
||
|
if (wpa) {
|
||
|
ap = &wpa->ia.ap;
|
||
|
ap->num_pages = 0;
|
||
|
ap->pages = fuse_pages_alloc(1, GFP_NOFS, &ap->descs);
|
||
|
if (!ap->pages) {
|
||
|
kfree(wpa);
|
||
|
wpa = NULL;
|
||
|
}
|
||
|
}
|
||
|
return wpa;
|
||
|
|
||
|
}
|
||
|
|
||
|
static void fuse_writepage_add_to_bucket(struct fuse_conn *fc,
|
||
|
struct fuse_writepage_args *wpa)
|
||
|
{
|
||
|
if (!fc->sync_fs)
|
||
|
return;
|
||
|
|
||
|
rcu_read_lock();
|
||
|
/* Prevent resurrection of dead bucket in unlikely race with syncfs */
|
||
|
do {
|
||
|
wpa->bucket = rcu_dereference(fc->curr_bucket);
|
||
|
} while (unlikely(!atomic_inc_not_zero(&wpa->bucket->count)));
|
||
|
rcu_read_unlock();
|
||
|
}
|
||
|
|
||
|
static int fuse_writepage_locked(struct page *page)
|
||
|
{
|
||
|
struct address_space *mapping = page->mapping;
|
||
|
struct inode *inode = mapping->host;
|
||
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
||
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
||
|
struct fuse_writepage_args *wpa;
|
||
|
struct fuse_args_pages *ap;
|
||
|
struct page *tmp_page;
|
||
|
int error = -ENOMEM;
|
||
|
|
||
|
set_page_writeback(page);
|
||
|
|
||
|
wpa = fuse_writepage_args_alloc();
|
||
|
if (!wpa)
|
||
|
goto err;
|
||
|
ap = &wpa->ia.ap;
|
||
|
|
||
|
tmp_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
|
||
|
if (!tmp_page)
|
||
|
goto err_free;
|
||
|
|
||
|
error = -EIO;
|
||
|
wpa->ia.ff = fuse_write_file_get(fi);
|
||
|
if (!wpa->ia.ff)
|
||
|
goto err_nofile;
|
||
|
|
||
|
fuse_writepage_add_to_bucket(fc, wpa);
|
||
|
fuse_write_args_fill(&wpa->ia, wpa->ia.ff, page_offset(page), 0);
|
||
|
|
||
|
copy_highpage(tmp_page, page);
|
||
|
wpa->ia.write.in.write_flags |= FUSE_WRITE_CACHE;
|
||
|
wpa->next = NULL;
|
||
|
ap->args.in_pages = true;
|
||
|
ap->num_pages = 1;
|
||
|
ap->pages[0] = tmp_page;
|
||
|
ap->descs[0].offset = 0;
|
||
|
ap->descs[0].length = PAGE_SIZE;
|
||
|
ap->args.end = fuse_writepage_end;
|
||
|
wpa->inode = inode;
|
||
|
|
||
|
inc_wb_stat(&inode_to_bdi(inode)->wb, WB_WRITEBACK);
|
||
|
inc_node_page_state(tmp_page, NR_WRITEBACK_TEMP);
|
||
|
|
||
|
spin_lock(&fi->lock);
|
||
|
tree_insert(&fi->writepages, wpa);
|
||
|
list_add_tail(&wpa->queue_entry, &fi->queued_writes);
|
||
|
fuse_flush_writepages(inode);
|
||
|
spin_unlock(&fi->lock);
|
||
|
|
||
|
end_page_writeback(page);
|
||
|
|
||
|
return 0;
|
||
|
|
||
|
err_nofile:
|
||
|
__free_page(tmp_page);
|
||
|
err_free:
|
||
|
kfree(wpa);
|
||
|
err:
|
||
|
mapping_set_error(page->mapping, error);
|
||
|
end_page_writeback(page);
|
||
|
return error;
|
||
|
}
|
||
|
|
||
|
static int fuse_writepage(struct page *page, struct writeback_control *wbc)
|
||
|
{
|
||
|
struct fuse_conn *fc = get_fuse_conn(page->mapping->host);
|
||
|
int err;
|
||
|
|
||
|
if (fuse_page_is_writeback(page->mapping->host, page->index)) {
|
||
|
/*
|
||
|
* ->writepages() should be called for sync() and friends. We
|
||
|
* should only get here on direct reclaim and then we are
|
||
|
* allowed to skip a page which is already in flight
|
||
|
*/
|
||
|
WARN_ON(wbc->sync_mode == WB_SYNC_ALL);
|
||
|
|
||
|
redirty_page_for_writepage(wbc, page);
|
||
|
unlock_page(page);
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
if (wbc->sync_mode == WB_SYNC_NONE &&
|
||
|
fc->num_background >= fc->congestion_threshold)
|
||
|
return AOP_WRITEPAGE_ACTIVATE;
|
||
|
|
||
|
err = fuse_writepage_locked(page);
|
||
|
unlock_page(page);
|
||
|
|
||
|
return err;
|
||
|
}
|
||
|
|
||
|
struct fuse_fill_wb_data {
|
||
|
struct fuse_writepage_args *wpa;
|
||
|
struct fuse_file *ff;
|
||
|
struct inode *inode;
|
||
|
struct page **orig_pages;
|
||
|
unsigned int max_pages;
|
||
|
};
|
||
|
|
||
|
static bool fuse_pages_realloc(struct fuse_fill_wb_data *data)
|
||
|
{
|
||
|
struct fuse_args_pages *ap = &data->wpa->ia.ap;
|
||
|
struct fuse_conn *fc = get_fuse_conn(data->inode);
|
||
|
struct page **pages;
|
||
|
struct fuse_page_desc *descs;
|
||
|
unsigned int npages = min_t(unsigned int,
|
||
|
max_t(unsigned int, data->max_pages * 2,
|
||
|
FUSE_DEFAULT_MAX_PAGES_PER_REQ),
|
||
|
fc->max_pages);
|
||
|
WARN_ON(npages <= data->max_pages);
|
||
|
|
||
|
pages = fuse_pages_alloc(npages, GFP_NOFS, &descs);
|
||
|
if (!pages)
|
||
|
return false;
|
||
|
|
||
|
memcpy(pages, ap->pages, sizeof(struct page *) * ap->num_pages);
|
||
|
memcpy(descs, ap->descs, sizeof(struct fuse_page_desc) * ap->num_pages);
|
||
|
kfree(ap->pages);
|
||
|
ap->pages = pages;
|
||
|
ap->descs = descs;
|
||
|
data->max_pages = npages;
|
||
|
|
||
|
return true;
|
||
|
}
|
||
|
|
||
|
static void fuse_writepages_send(struct fuse_fill_wb_data *data)
|
||
|
{
|
||
|
struct fuse_writepage_args *wpa = data->wpa;
|
||
|
struct inode *inode = data->inode;
|
||
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
||
|
int num_pages = wpa->ia.ap.num_pages;
|
||
|
int i;
|
||
|
|
||
|
wpa->ia.ff = fuse_file_get(data->ff);
|
||
|
spin_lock(&fi->lock);
|
||
|
list_add_tail(&wpa->queue_entry, &fi->queued_writes);
|
||
|
fuse_flush_writepages(inode);
|
||
|
spin_unlock(&fi->lock);
|
||
|
|
||
|
for (i = 0; i < num_pages; i++)
|
||
|
end_page_writeback(data->orig_pages[i]);
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* Check under fi->lock if the page is under writeback, and insert it onto the
|
||
|
* rb_tree if not. Otherwise iterate auxiliary write requests, to see if there's
|
||
|
* one already added for a page at this offset. If there's none, then insert
|
||
|
* this new request onto the auxiliary list, otherwise reuse the existing one by
|
||
|
* swapping the new temp page with the old one.
|
||
|
*/
|
||
|
static bool fuse_writepage_add(struct fuse_writepage_args *new_wpa,
|
||
|
struct page *page)
|
||
|
{
|
||
|
struct fuse_inode *fi = get_fuse_inode(new_wpa->inode);
|
||
|
struct fuse_writepage_args *tmp;
|
||
|
struct fuse_writepage_args *old_wpa;
|
||
|
struct fuse_args_pages *new_ap = &new_wpa->ia.ap;
|
||
|
|
||
|
WARN_ON(new_ap->num_pages != 0);
|
||
|
new_ap->num_pages = 1;
|
||
|
|
||
|
spin_lock(&fi->lock);
|
||
|
old_wpa = fuse_insert_writeback(&fi->writepages, new_wpa);
|
||
|
if (!old_wpa) {
|
||
|
spin_unlock(&fi->lock);
|
||
|
return true;
|
||
|
}
|
||
|
|
||
|
for (tmp = old_wpa->next; tmp; tmp = tmp->next) {
|
||
|
pgoff_t curr_index;
|
||
|
|
||
|
WARN_ON(tmp->inode != new_wpa->inode);
|
||
|
curr_index = tmp->ia.write.in.offset >> PAGE_SHIFT;
|
||
|
if (curr_index == page->index) {
|
||
|
WARN_ON(tmp->ia.ap.num_pages != 1);
|
||
|
swap(tmp->ia.ap.pages[0], new_ap->pages[0]);
|
||
|
break;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
if (!tmp) {
|
||
|
new_wpa->next = old_wpa->next;
|
||
|
old_wpa->next = new_wpa;
|
||
|
}
|
||
|
|
||
|
spin_unlock(&fi->lock);
|
||
|
|
||
|
if (tmp) {
|
||
|
struct backing_dev_info *bdi = inode_to_bdi(new_wpa->inode);
|
||
|
|
||
|
dec_wb_stat(&bdi->wb, WB_WRITEBACK);
|
||
|
dec_node_page_state(new_ap->pages[0], NR_WRITEBACK_TEMP);
|
||
|
wb_writeout_inc(&bdi->wb);
|
||
|
fuse_writepage_free(new_wpa);
|
||
|
}
|
||
|
|
||
|
return false;
|
||
|
}
|
||
|
|
||
|
static bool fuse_writepage_need_send(struct fuse_conn *fc, struct page *page,
|
||
|
struct fuse_args_pages *ap,
|
||
|
struct fuse_fill_wb_data *data)
|
||
|
{
|
||
|
WARN_ON(!ap->num_pages);
|
||
|
|
||
|
/*
|
||
|
* Being under writeback is unlikely but possible. For example direct
|
||
|
* read to an mmaped fuse file will set the page dirty twice; once when
|
||
|
* the pages are faulted with get_user_pages(), and then after the read
|
||
|
* completed.
|
||
|
*/
|
||
|
if (fuse_page_is_writeback(data->inode, page->index))
|
||
|
return true;
|
||
|
|
||
|
/* Reached max pages */
|
||
|
if (ap->num_pages == fc->max_pages)
|
||
|
return true;
|
||
|
|
||
|
/* Reached max write bytes */
|
||
|
if ((ap->num_pages + 1) * PAGE_SIZE > fc->max_write)
|
||
|
return true;
|
||
|
|
||
|
/* Discontinuity */
|
||
|
if (data->orig_pages[ap->num_pages - 1]->index + 1 != page->index)
|
||
|
return true;
|
||
|
|
||
|
/* Need to grow the pages array? If so, did the expansion fail? */
|
||
|
if (ap->num_pages == data->max_pages && !fuse_pages_realloc(data))
|
||
|
return true;
|
||
|
|
||
|
return false;
|
||
|
}
|
||
|
|
||
|
static int fuse_writepages_fill(struct page *page,
|
||
|
struct writeback_control *wbc, void *_data)
|
||
|
{
|
||
|
struct fuse_fill_wb_data *data = _data;
|
||
|
struct fuse_writepage_args *wpa = data->wpa;
|
||
|
struct fuse_args_pages *ap = &wpa->ia.ap;
|
||
|
struct inode *inode = data->inode;
|
||
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
||
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
||
|
struct page *tmp_page;
|
||
|
int err;
|
||
|
|
||
|
if (!data->ff) {
|
||
|
err = -EIO;
|
||
|
data->ff = fuse_write_file_get(fi);
|
||
|
if (!data->ff)
|
||
|
goto out_unlock;
|
||
|
}
|
||
|
|
||
|
if (wpa && fuse_writepage_need_send(fc, page, ap, data)) {
|
||
|
fuse_writepages_send(data);
|
||
|
data->wpa = NULL;
|
||
|
}
|
||
|
|
||
|
err = -ENOMEM;
|
||
|
tmp_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
|
||
|
if (!tmp_page)
|
||
|
goto out_unlock;
|
||
|
|
||
|
/*
|
||
|
* The page must not be redirtied until the writeout is completed
|
||
|
* (i.e. userspace has sent a reply to the write request). Otherwise
|
||
|
* there could be more than one temporary page instance for each real
|
||
|
* page.
|
||
|
*
|
||
|
* This is ensured by holding the page lock in page_mkwrite() while
|
||
|
* checking fuse_page_is_writeback(). We already hold the page lock
|
||
|
* since clear_page_dirty_for_io() and keep it held until we add the
|
||
|
* request to the fi->writepages list and increment ap->num_pages.
|
||
|
* After this fuse_page_is_writeback() will indicate that the page is
|
||
|
* under writeback, so we can release the page lock.
|
||
|
*/
|
||
|
if (data->wpa == NULL) {
|
||
|
err = -ENOMEM;
|
||
|
wpa = fuse_writepage_args_alloc();
|
||
|
if (!wpa) {
|
||
|
__free_page(tmp_page);
|
||
|
goto out_unlock;
|
||
|
}
|
||
|
fuse_writepage_add_to_bucket(fc, wpa);
|
||
|
|
||
|
data->max_pages = 1;
|
||
|
|
||
|
ap = &wpa->ia.ap;
|
||
|
fuse_write_args_fill(&wpa->ia, data->ff, page_offset(page), 0);
|
||
|
wpa->ia.write.in.write_flags |= FUSE_WRITE_CACHE;
|
||
|
wpa->next = NULL;
|
||
|
ap->args.in_pages = true;
|
||
|
ap->args.end = fuse_writepage_end;
|
||
|
ap->num_pages = 0;
|
||
|
wpa->inode = inode;
|
||
|
}
|
||
|
set_page_writeback(page);
|
||
|
|
||
|
copy_highpage(tmp_page, page);
|
||
|
ap->pages[ap->num_pages] = tmp_page;
|
||
|
ap->descs[ap->num_pages].offset = 0;
|
||
|
ap->descs[ap->num_pages].length = PAGE_SIZE;
|
||
|
data->orig_pages[ap->num_pages] = page;
|
||
|
|
||
|
inc_wb_stat(&inode_to_bdi(inode)->wb, WB_WRITEBACK);
|
||
|
inc_node_page_state(tmp_page, NR_WRITEBACK_TEMP);
|
||
|
|
||
|
err = 0;
|
||
|
if (data->wpa) {
|
||
|
/*
|
||
|
* Protected by fi->lock against concurrent access by
|
||
|
* fuse_page_is_writeback().
|
||
|
*/
|
||
|
spin_lock(&fi->lock);
|
||
|
ap->num_pages++;
|
||
|
spin_unlock(&fi->lock);
|
||
|
} else if (fuse_writepage_add(wpa, page)) {
|
||
|
data->wpa = wpa;
|
||
|
} else {
|
||
|
end_page_writeback(page);
|
||
|
}
|
||
|
out_unlock:
|
||
|
unlock_page(page);
|
||
|
|
||
|
return err;
|
||
|
}
|
||
|
|
||
|
static int fuse_writepages(struct address_space *mapping,
|
||
|
struct writeback_control *wbc)
|
||
|
{
|
||
|
struct inode *inode = mapping->host;
|
||
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
||
|
struct fuse_fill_wb_data data;
|
||
|
int err;
|
||
|
|
||
|
err = -EIO;
|
||
|
if (fuse_is_bad(inode))
|
||
|
goto out;
|
||
|
|
||
|
if (wbc->sync_mode == WB_SYNC_NONE &&
|
||
|
fc->num_background >= fc->congestion_threshold)
|
||
|
return 0;
|
||
|
|
||
|
data.inode = inode;
|
||
|
data.wpa = NULL;
|
||
|
data.ff = NULL;
|
||
|
|
||
|
err = -ENOMEM;
|
||
|
data.orig_pages = kcalloc(fc->max_pages,
|
||
|
sizeof(struct page *),
|
||
|
GFP_NOFS);
|
||
|
if (!data.orig_pages)
|
||
|
goto out;
|
||
|
|
||
|
err = write_cache_pages(mapping, wbc, fuse_writepages_fill, &data);
|
||
|
if (data.wpa) {
|
||
|
WARN_ON(!data.wpa->ia.ap.num_pages);
|
||
|
fuse_writepages_send(&data);
|
||
|
}
|
||
|
if (data.ff)
|
||
|
fuse_file_put(data.ff, false, false);
|
||
|
|
||
|
kfree(data.orig_pages);
|
||
|
out:
|
||
|
return err;
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* It's worthy to make sure that space is reserved on disk for the write,
|
||
|
* but how to implement it without killing performance need more thinking.
|
||
|
*/
|
||
|
static int fuse_write_begin(struct file *file, struct address_space *mapping,
|
||
|
loff_t pos, unsigned len, struct page **pagep, void **fsdata)
|
||
|
{
|
||
|
pgoff_t index = pos >> PAGE_SHIFT;
|
||
|
struct fuse_conn *fc = get_fuse_conn(file_inode(file));
|
||
|
struct page *page;
|
||
|
loff_t fsize;
|
||
|
int err = -ENOMEM;
|
||
|
|
||
|
WARN_ON(!fc->writeback_cache);
|
||
|
|
||
|
page = grab_cache_page_write_begin(mapping, index);
|
||
|
if (!page)
|
||
|
goto error;
|
||
|
|
||
|
fuse_wait_on_page_writeback(mapping->host, page->index);
|
||
|
|
||
|
if (PageUptodate(page) || len == PAGE_SIZE)
|
||
|
goto success;
|
||
|
/*
|
||
|
* Check if the start this page comes after the end of file, in which
|
||
|
* case the readpage can be optimized away.
|
||
|
*/
|
||
|
fsize = i_size_read(mapping->host);
|
||
|
if (fsize <= (pos & PAGE_MASK)) {
|
||
|
size_t off = pos & ~PAGE_MASK;
|
||
|
if (off)
|
||
|
zero_user_segment(page, 0, off);
|
||
|
goto success;
|
||
|
}
|
||
|
err = fuse_do_readpage(file, page);
|
||
|
if (err)
|
||
|
goto cleanup;
|
||
|
success:
|
||
|
*pagep = page;
|
||
|
return 0;
|
||
|
|
||
|
cleanup:
|
||
|
unlock_page(page);
|
||
|
put_page(page);
|
||
|
error:
|
||
|
return err;
|
||
|
}
|
||
|
|
||
|
static int fuse_write_end(struct file *file, struct address_space *mapping,
|
||
|
loff_t pos, unsigned len, unsigned copied,
|
||
|
struct page *page, void *fsdata)
|
||
|
{
|
||
|
struct inode *inode = page->mapping->host;
|
||
|
|
||
|
/* Haven't copied anything? Skip zeroing, size extending, dirtying. */
|
||
|
if (!copied)
|
||
|
goto unlock;
|
||
|
|
||
|
pos += copied;
|
||
|
if (!PageUptodate(page)) {
|
||
|
/* Zero any unwritten bytes at the end of the page */
|
||
|
size_t endoff = pos & ~PAGE_MASK;
|
||
|
if (endoff)
|
||
|
zero_user_segment(page, endoff, PAGE_SIZE);
|
||
|
SetPageUptodate(page);
|
||
|
}
|
||
|
|
||
|
if (pos > inode->i_size)
|
||
|
i_size_write(inode, pos);
|
||
|
|
||
|
set_page_dirty(page);
|
||
|
|
||
|
unlock:
|
||
|
unlock_page(page);
|
||
|
put_page(page);
|
||
|
|
||
|
return copied;
|
||
|
}
|
||
|
|
||
|
static int fuse_launder_folio(struct folio *folio)
|
||
|
{
|
||
|
int err = 0;
|
||
|
if (folio_clear_dirty_for_io(folio)) {
|
||
|
struct inode *inode = folio->mapping->host;
|
||
|
|
||
|
/* Serialize with pending writeback for the same page */
|
||
|
fuse_wait_on_page_writeback(inode, folio->index);
|
||
|
err = fuse_writepage_locked(&folio->page);
|
||
|
if (!err)
|
||
|
fuse_wait_on_page_writeback(inode, folio->index);
|
||
|
}
|
||
|
return err;
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* Write back dirty data/metadata now (there may not be any suitable
|
||
|
* open files later for data)
|
||
|
*/
|
||
|
static void fuse_vma_close(struct vm_area_struct *vma)
|
||
|
{
|
||
|
int err;
|
||
|
|
||
|
err = write_inode_now(vma->vm_file->f_mapping->host, 1);
|
||
|
mapping_set_error(vma->vm_file->f_mapping, err);
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* Wait for writeback against this page to complete before allowing it
|
||
|
* to be marked dirty again, and hence written back again, possibly
|
||
|
* before the previous writepage completed.
|
||
|
*
|
||
|
* Block here, instead of in ->writepage(), so that the userspace fs
|
||
|
* can only block processes actually operating on the filesystem.
|
||
|
*
|
||
|
* Otherwise unprivileged userspace fs would be able to block
|
||
|
* unrelated:
|
||
|
*
|
||
|
* - page migration
|
||
|
* - sync(2)
|
||
|
* - try_to_free_pages() with order > PAGE_ALLOC_COSTLY_ORDER
|
||
|
*/
|
||
|
static vm_fault_t fuse_page_mkwrite(struct vm_fault *vmf)
|
||
|
{
|
||
|
struct page *page = vmf->page;
|
||
|
struct inode *inode = file_inode(vmf->vma->vm_file);
|
||
|
|
||
|
file_update_time(vmf->vma->vm_file);
|
||
|
lock_page(page);
|
||
|
if (page->mapping != inode->i_mapping) {
|
||
|
unlock_page(page);
|
||
|
return VM_FAULT_NOPAGE;
|
||
|
}
|
||
|
|
||
|
fuse_wait_on_page_writeback(inode, page->index);
|
||
|
return VM_FAULT_LOCKED;
|
||
|
}
|
||
|
|
||
|
static const struct vm_operations_struct fuse_file_vm_ops = {
|
||
|
.close = fuse_vma_close,
|
||
|
.fault = filemap_fault,
|
||
|
.map_pages = filemap_map_pages,
|
||
|
.page_mkwrite = fuse_page_mkwrite,
|
||
|
};
|
||
|
|
||
|
static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma)
|
||
|
{
|
||
|
struct fuse_file *ff = file->private_data;
|
||
|
|
||
|
/* DAX mmap is superior to direct_io mmap */
|
||
|
if (FUSE_IS_DAX(file_inode(file)))
|
||
|
return fuse_dax_mmap(file, vma);
|
||
|
|
||
|
if (ff->open_flags & FOPEN_DIRECT_IO) {
|
||
|
/* Can't provide the coherency needed for MAP_SHARED */
|
||
|
if (vma->vm_flags & VM_MAYSHARE)
|
||
|
return -ENODEV;
|
||
|
|
||
|
invalidate_inode_pages2(file->f_mapping);
|
||
|
|
||
|
return generic_file_mmap(file, vma);
|
||
|
}
|
||
|
|
||
|
if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE))
|
||
|
fuse_link_write_file(file);
|
||
|
|
||
|
file_accessed(file);
|
||
|
vma->vm_ops = &fuse_file_vm_ops;
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static int convert_fuse_file_lock(struct fuse_conn *fc,
|
||
|
const struct fuse_file_lock *ffl,
|
||
|
struct file_lock *fl)
|
||
|
{
|
||
|
switch (ffl->type) {
|
||
|
case F_UNLCK:
|
||
|
break;
|
||
|
|
||
|
case F_RDLCK:
|
||
|
case F_WRLCK:
|
||
|
if (ffl->start > OFFSET_MAX || ffl->end > OFFSET_MAX ||
|
||
|
ffl->end < ffl->start)
|
||
|
return -EIO;
|
||
|
|
||
|
fl->fl_start = ffl->start;
|
||
|
fl->fl_end = ffl->end;
|
||
|
|
||
|
/*
|
||
|
* Convert pid into init's pid namespace. The locks API will
|
||
|
* translate it into the caller's pid namespace.
|
||
|
*/
|
||
|
rcu_read_lock();
|
||
|
fl->fl_pid = pid_nr_ns(find_pid_ns(ffl->pid, fc->pid_ns), &init_pid_ns);
|
||
|
rcu_read_unlock();
|
||
|
break;
|
||
|
|
||
|
default:
|
||
|
return -EIO;
|
||
|
}
|
||
|
fl->fl_type = ffl->type;
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static void fuse_lk_fill(struct fuse_args *args, struct file *file,
|
||
|
const struct file_lock *fl, int opcode, pid_t pid,
|
||
|
int flock, struct fuse_lk_in *inarg)
|
||
|
{
|
||
|
struct inode *inode = file_inode(file);
|
||
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
||
|
struct fuse_file *ff = file->private_data;
|
||
|
|
||
|
memset(inarg, 0, sizeof(*inarg));
|
||
|
inarg->fh = ff->fh;
|
||
|
inarg->owner = fuse_lock_owner_id(fc, fl->fl_owner);
|
||
|
inarg->lk.start = fl->fl_start;
|
||
|
inarg->lk.end = fl->fl_end;
|
||
|
inarg->lk.type = fl->fl_type;
|
||
|
inarg->lk.pid = pid;
|
||
|
if (flock)
|
||
|
inarg->lk_flags |= FUSE_LK_FLOCK;
|
||
|
args->opcode = opcode;
|
||
|
args->nodeid = get_node_id(inode);
|
||
|
args->in_numargs = 1;
|
||
|
args->in_args[0].size = sizeof(*inarg);
|
||
|
args->in_args[0].value = inarg;
|
||
|
}
|
||
|
|
||
|
static int fuse_getlk(struct file *file, struct file_lock *fl)
|
||
|
{
|
||
|
struct inode *inode = file_inode(file);
|
||
|
struct fuse_mount *fm = get_fuse_mount(inode);
|
||
|
FUSE_ARGS(args);
|
||
|
struct fuse_lk_in inarg;
|
||
|
struct fuse_lk_out outarg;
|
||
|
int err;
|
||
|
|
||
|
fuse_lk_fill(&args, file, fl, FUSE_GETLK, 0, 0, &inarg);
|
||
|
args.out_numargs = 1;
|
||
|
args.out_args[0].size = sizeof(outarg);
|
||
|
args.out_args[0].value = &outarg;
|
||
|
err = fuse_simple_request(fm, &args);
|
||
|
if (!err)
|
||
|
err = convert_fuse_file_lock(fm->fc, &outarg.lk, fl);
|
||
|
|
||
|
return err;
|
||
|
}
|
||
|
|
||
|
static int fuse_setlk(struct file *file, struct file_lock *fl, int flock)
|
||
|
{
|
||
|
struct inode *inode = file_inode(file);
|
||
|
struct fuse_mount *fm = get_fuse_mount(inode);
|
||
|
FUSE_ARGS(args);
|
||
|
struct fuse_lk_in inarg;
|
||
|
int opcode = (fl->fl_flags & FL_SLEEP) ? FUSE_SETLKW : FUSE_SETLK;
|
||
|
struct pid *pid = fl->fl_type != F_UNLCK ? task_tgid(current) : NULL;
|
||
|
pid_t pid_nr = pid_nr_ns(pid, fm->fc->pid_ns);
|
||
|
int err;
|
||
|
|
||
|
if (fl->fl_lmops && fl->fl_lmops->lm_grant) {
|
||
|
/* NLM needs asynchronous locks, which we don't support yet */
|
||
|
return -ENOLCK;
|
||
|
}
|
||
|
|
||
|
/* Unlock on close is handled by the flush method */
|
||
|
if ((fl->fl_flags & FL_CLOSE_POSIX) == FL_CLOSE_POSIX)
|
||
|
return 0;
|
||
|
|
||
|
fuse_lk_fill(&args, file, fl, opcode, pid_nr, flock, &inarg);
|
||
|
err = fuse_simple_request(fm, &args);
|
||
|
|
||
|
/* locking is restartable */
|
||
|
if (err == -EINTR)
|
||
|
err = -ERESTARTSYS;
|
||
|
|
||
|
return err;
|
||
|
}
|
||
|
|
||
|
static int fuse_file_lock(struct file *file, int cmd, struct file_lock *fl)
|
||
|
{
|
||
|
struct inode *inode = file_inode(file);
|
||
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
||
|
int err;
|
||
|
|
||
|
if (cmd == F_CANCELLK) {
|
||
|
err = 0;
|
||
|
} else if (cmd == F_GETLK) {
|
||
|
if (fc->no_lock) {
|
||
|
posix_test_lock(file, fl);
|
||
|
err = 0;
|
||
|
} else
|
||
|
err = fuse_getlk(file, fl);
|
||
|
} else {
|
||
|
if (fc->no_lock)
|
||
|
err = posix_lock_file(file, fl, NULL);
|
||
|
else
|
||
|
err = fuse_setlk(file, fl, 0);
|
||
|
}
|
||
|
return err;
|
||
|
}
|
||
|
|
||
|
static int fuse_file_flock(struct file *file, int cmd, struct file_lock *fl)
|
||
|
{
|
||
|
struct inode *inode = file_inode(file);
|
||
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
||
|
int err;
|
||
|
|
||
|
if (fc->no_flock) {
|
||
|
err = locks_lock_file_wait(file, fl);
|
||
|
} else {
|
||
|
struct fuse_file *ff = file->private_data;
|
||
|
|
||
|
/* emulate flock with POSIX locks */
|
||
|
ff->flock = true;
|
||
|
err = fuse_setlk(file, fl, 1);
|
||
|
}
|
||
|
|
||
|
return err;
|
||
|
}
|
||
|
|
||
|
static sector_t fuse_bmap(struct address_space *mapping, sector_t block)
|
||
|
{
|
||
|
struct inode *inode = mapping->host;
|
||
|
struct fuse_mount *fm = get_fuse_mount(inode);
|
||
|
FUSE_ARGS(args);
|
||
|
struct fuse_bmap_in inarg;
|
||
|
struct fuse_bmap_out outarg;
|
||
|
int err;
|
||
|
|
||
|
if (!inode->i_sb->s_bdev || fm->fc->no_bmap)
|
||
|
return 0;
|
||
|
|
||
|
memset(&inarg, 0, sizeof(inarg));
|
||
|
inarg.block = block;
|
||
|
inarg.blocksize = inode->i_sb->s_blocksize;
|
||
|
args.opcode = FUSE_BMAP;
|
||
|
args.nodeid = get_node_id(inode);
|
||
|
args.in_numargs = 1;
|
||
|
args.in_args[0].size = sizeof(inarg);
|
||
|
args.in_args[0].value = &inarg;
|
||
|
args.out_numargs = 1;
|
||
|
args.out_args[0].size = sizeof(outarg);
|
||
|
args.out_args[0].value = &outarg;
|
||
|
err = fuse_simple_request(fm, &args);
|
||
|
if (err == -ENOSYS)
|
||
|
fm->fc->no_bmap = 1;
|
||
|
|
||
|
return err ? 0 : outarg.block;
|
||
|
}
|
||
|
|
||
|
static loff_t fuse_lseek(struct file *file, loff_t offset, int whence)
|
||
|
{
|
||
|
struct inode *inode = file->f_mapping->host;
|
||
|
struct fuse_mount *fm = get_fuse_mount(inode);
|
||
|
struct fuse_file *ff = file->private_data;
|
||
|
FUSE_ARGS(args);
|
||
|
struct fuse_lseek_in inarg = {
|
||
|
.fh = ff->fh,
|
||
|
.offset = offset,
|
||
|
.whence = whence
|
||
|
};
|
||
|
struct fuse_lseek_out outarg;
|
||
|
int err;
|
||
|
|
||
|
if (fm->fc->no_lseek)
|
||
|
goto fallback;
|
||
|
|
||
|
args.opcode = FUSE_LSEEK;
|
||
|
args.nodeid = ff->nodeid;
|
||
|
args.in_numargs = 1;
|
||
|
args.in_args[0].size = sizeof(inarg);
|
||
|
args.in_args[0].value = &inarg;
|
||
|
args.out_numargs = 1;
|
||
|
args.out_args[0].size = sizeof(outarg);
|
||
|
args.out_args[0].value = &outarg;
|
||
|
err = fuse_simple_request(fm, &args);
|
||
|
if (err) {
|
||
|
if (err == -ENOSYS) {
|
||
|
fm->fc->no_lseek = 1;
|
||
|
goto fallback;
|
||
|
}
|
||
|
return err;
|
||
|
}
|
||
|
|
||
|
return vfs_setpos(file, outarg.offset, inode->i_sb->s_maxbytes);
|
||
|
|
||
|
fallback:
|
||
|
err = fuse_update_attributes(inode, file, STATX_SIZE);
|
||
|
if (!err)
|
||
|
return generic_file_llseek(file, offset, whence);
|
||
|
else
|
||
|
return err;
|
||
|
}
|
||
|
|
||
|
static loff_t fuse_file_llseek(struct file *file, loff_t offset, int whence)
|
||
|
{
|
||
|
loff_t retval;
|
||
|
struct inode *inode = file_inode(file);
|
||
|
|
||
|
switch (whence) {
|
||
|
case SEEK_SET:
|
||
|
case SEEK_CUR:
|
||
|
/* No i_mutex protection necessary for SEEK_CUR and SEEK_SET */
|
||
|
retval = generic_file_llseek(file, offset, whence);
|
||
|
break;
|
||
|
case SEEK_END:
|
||
|
inode_lock(inode);
|
||
|
retval = fuse_update_attributes(inode, file, STATX_SIZE);
|
||
|
if (!retval)
|
||
|
retval = generic_file_llseek(file, offset, whence);
|
||
|
inode_unlock(inode);
|
||
|
break;
|
||
|
case SEEK_HOLE:
|
||
|
case SEEK_DATA:
|
||
|
inode_lock(inode);
|
||
|
retval = fuse_lseek(file, offset, whence);
|
||
|
inode_unlock(inode);
|
||
|
break;
|
||
|
default:
|
||
|
retval = -EINVAL;
|
||
|
}
|
||
|
|
||
|
return retval;
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* All files which have been polled are linked to RB tree
|
||
|
* fuse_conn->polled_files which is indexed by kh. Walk the tree and
|
||
|
* find the matching one.
|
||
|
*/
|
||
|
static struct rb_node **fuse_find_polled_node(struct fuse_conn *fc, u64 kh,
|
||
|
struct rb_node **parent_out)
|
||
|
{
|
||
|
struct rb_node **link = &fc->polled_files.rb_node;
|
||
|
struct rb_node *last = NULL;
|
||
|
|
||
|
while (*link) {
|
||
|
struct fuse_file *ff;
|
||
|
|
||
|
last = *link;
|
||
|
ff = rb_entry(last, struct fuse_file, polled_node);
|
||
|
|
||
|
if (kh < ff->kh)
|
||
|
link = &last->rb_left;
|
||
|
else if (kh > ff->kh)
|
||
|
link = &last->rb_right;
|
||
|
else
|
||
|
return link;
|
||
|
}
|
||
|
|
||
|
if (parent_out)
|
||
|
*parent_out = last;
|
||
|
return link;
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* The file is about to be polled. Make sure it's on the polled_files
|
||
|
* RB tree. Note that files once added to the polled_files tree are
|
||
|
* not removed before the file is released. This is because a file
|
||
|
* polled once is likely to be polled again.
|
||
|
*/
|
||
|
static void fuse_register_polled_file(struct fuse_conn *fc,
|
||
|
struct fuse_file *ff)
|
||
|
{
|
||
|
spin_lock(&fc->lock);
|
||
|
if (RB_EMPTY_NODE(&ff->polled_node)) {
|
||
|
struct rb_node **link, *parent;
|
||
|
|
||
|
link = fuse_find_polled_node(fc, ff->kh, &parent);
|
||
|
BUG_ON(*link);
|
||
|
rb_link_node(&ff->polled_node, parent, link);
|
||
|
rb_insert_color(&ff->polled_node, &fc->polled_files);
|
||
|
}
|
||
|
spin_unlock(&fc->lock);
|
||
|
}
|
||
|
|
||
|
__poll_t fuse_file_poll(struct file *file, poll_table *wait)
|
||
|
{
|
||
|
struct fuse_file *ff = file->private_data;
|
||
|
struct fuse_mount *fm = ff->fm;
|
||
|
struct fuse_poll_in inarg = { .fh = ff->fh, .kh = ff->kh };
|
||
|
struct fuse_poll_out outarg;
|
||
|
FUSE_ARGS(args);
|
||
|
int err;
|
||
|
|
||
|
if (fm->fc->no_poll)
|
||
|
return DEFAULT_POLLMASK;
|
||
|
|
||
|
poll_wait(file, &ff->poll_wait, wait);
|
||
|
inarg.events = mangle_poll(poll_requested_events(wait));
|
||
|
|
||
|
/*
|
||
|
* Ask for notification iff there's someone waiting for it.
|
||
|
* The client may ignore the flag and always notify.
|
||
|
*/
|
||
|
if (waitqueue_active(&ff->poll_wait)) {
|
||
|
inarg.flags |= FUSE_POLL_SCHEDULE_NOTIFY;
|
||
|
fuse_register_polled_file(fm->fc, ff);
|
||
|
}
|
||
|
|
||
|
args.opcode = FUSE_POLL;
|
||
|
args.nodeid = ff->nodeid;
|
||
|
args.in_numargs = 1;
|
||
|
args.in_args[0].size = sizeof(inarg);
|
||
|
args.in_args[0].value = &inarg;
|
||
|
args.out_numargs = 1;
|
||
|
args.out_args[0].size = sizeof(outarg);
|
||
|
args.out_args[0].value = &outarg;
|
||
|
err = fuse_simple_request(fm, &args);
|
||
|
|
||
|
if (!err)
|
||
|
return demangle_poll(outarg.revents);
|
||
|
if (err == -ENOSYS) {
|
||
|
fm->fc->no_poll = 1;
|
||
|
return DEFAULT_POLLMASK;
|
||
|
}
|
||
|
return EPOLLERR;
|
||
|
}
|
||
|
EXPORT_SYMBOL_GPL(fuse_file_poll);
|
||
|
|
||
|
/*
|
||
|
* This is called from fuse_handle_notify() on FUSE_NOTIFY_POLL and
|
||
|
* wakes up the poll waiters.
|
||
|
*/
|
||
|
int fuse_notify_poll_wakeup(struct fuse_conn *fc,
|
||
|
struct fuse_notify_poll_wakeup_out *outarg)
|
||
|
{
|
||
|
u64 kh = outarg->kh;
|
||
|
struct rb_node **link;
|
||
|
|
||
|
spin_lock(&fc->lock);
|
||
|
|
||
|
link = fuse_find_polled_node(fc, kh, NULL);
|
||
|
if (*link) {
|
||
|
struct fuse_file *ff;
|
||
|
|
||
|
ff = rb_entry(*link, struct fuse_file, polled_node);
|
||
|
wake_up_interruptible_sync(&ff->poll_wait);
|
||
|
}
|
||
|
|
||
|
spin_unlock(&fc->lock);
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static void fuse_do_truncate(struct file *file)
|
||
|
{
|
||
|
struct inode *inode = file->f_mapping->host;
|
||
|
struct iattr attr;
|
||
|
|
||
|
attr.ia_valid = ATTR_SIZE;
|
||
|
attr.ia_size = i_size_read(inode);
|
||
|
|
||
|
attr.ia_file = file;
|
||
|
attr.ia_valid |= ATTR_FILE;
|
||
|
|
||
|
fuse_do_setattr(file_dentry(file), &attr, file);
|
||
|
}
|
||
|
|
||
|
static inline loff_t fuse_round_up(struct fuse_conn *fc, loff_t off)
|
||
|
{
|
||
|
return round_up(off, fc->max_pages << PAGE_SHIFT);
|
||
|
}
|
||
|
|
||
|
static ssize_t
|
||
|
fuse_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
|
||
|
{
|
||
|
DECLARE_COMPLETION_ONSTACK(wait);
|
||
|
ssize_t ret = 0;
|
||
|
struct file *file = iocb->ki_filp;
|
||
|
struct fuse_file *ff = file->private_data;
|
||
|
loff_t pos = 0;
|
||
|
struct inode *inode;
|
||
|
loff_t i_size;
|
||
|
size_t count = iov_iter_count(iter), shortened = 0;
|
||
|
loff_t offset = iocb->ki_pos;
|
||
|
struct fuse_io_priv *io;
|
||
|
|
||
|
pos = offset;
|
||
|
inode = file->f_mapping->host;
|
||
|
i_size = i_size_read(inode);
|
||
|
|
||
|
if ((iov_iter_rw(iter) == READ) && (offset >= i_size))
|
||
|
return 0;
|
||
|
|
||
|
io = kmalloc(sizeof(struct fuse_io_priv), GFP_KERNEL);
|
||
|
if (!io)
|
||
|
return -ENOMEM;
|
||
|
spin_lock_init(&io->lock);
|
||
|
kref_init(&io->refcnt);
|
||
|
io->reqs = 1;
|
||
|
io->bytes = -1;
|
||
|
io->size = 0;
|
||
|
io->offset = offset;
|
||
|
io->write = (iov_iter_rw(iter) == WRITE);
|
||
|
io->err = 0;
|
||
|
/*
|
||
|
* By default, we want to optimize all I/Os with async request
|
||
|
* submission to the client filesystem if supported.
|
||
|
*/
|
||
|
io->async = ff->fm->fc->async_dio;
|
||
|
io->iocb = iocb;
|
||
|
io->blocking = is_sync_kiocb(iocb);
|
||
|
|
||
|
/* optimization for short read */
|
||
|
if (io->async && !io->write && offset + count > i_size) {
|
||
|
iov_iter_truncate(iter, fuse_round_up(ff->fm->fc, i_size - offset));
|
||
|
shortened = count - iov_iter_count(iter);
|
||
|
count -= shortened;
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* We cannot asynchronously extend the size of a file.
|
||
|
* In such case the aio will behave exactly like sync io.
|
||
|
*/
|
||
|
if ((offset + count > i_size) && io->write)
|
||
|
io->blocking = true;
|
||
|
|
||
|
if (io->async && io->blocking) {
|
||
|
/*
|
||
|
* Additional reference to keep io around after
|
||
|
* calling fuse_aio_complete()
|
||
|
*/
|
||
|
kref_get(&io->refcnt);
|
||
|
io->done = &wait;
|
||
|
}
|
||
|
|
||
|
if (iov_iter_rw(iter) == WRITE) {
|
||
|
ret = fuse_direct_io(io, iter, &pos, FUSE_DIO_WRITE);
|
||
|
fuse_invalidate_attr_mask(inode, FUSE_STATX_MODSIZE);
|
||
|
} else {
|
||
|
ret = __fuse_direct_read(io, iter, &pos);
|
||
|
}
|
||
|
iov_iter_reexpand(iter, iov_iter_count(iter) + shortened);
|
||
|
|
||
|
if (io->async) {
|
||
|
bool blocking = io->blocking;
|
||
|
|
||
|
fuse_aio_complete(io, ret < 0 ? ret : 0, -1);
|
||
|
|
||
|
/* we have a non-extending, async request, so return */
|
||
|
if (!blocking)
|
||
|
return -EIOCBQUEUED;
|
||
|
|
||
|
wait_for_completion(&wait);
|
||
|
ret = fuse_get_res_by_io(io);
|
||
|
}
|
||
|
|
||
|
kref_put(&io->refcnt, fuse_io_release);
|
||
|
|
||
|
if (iov_iter_rw(iter) == WRITE) {
|
||
|
fuse_write_update_attr(inode, pos, ret);
|
||
|
if (ret < 0 && offset + count > i_size)
|
||
|
fuse_do_truncate(file);
|
||
|
}
|
||
|
|
||
|
return ret;
|
||
|
}
|
||
|
|
||
|
static int fuse_writeback_range(struct inode *inode, loff_t start, loff_t end)
|
||
|
{
|
||
|
int err = filemap_write_and_wait_range(inode->i_mapping, start, LLONG_MAX);
|
||
|
|
||
|
if (!err)
|
||
|
fuse_sync_writes(inode);
|
||
|
|
||
|
return err;
|
||
|
}
|
||
|
|
||
|
static long fuse_file_fallocate(struct file *file, int mode, loff_t offset,
|
||
|
loff_t length)
|
||
|
{
|
||
|
struct fuse_file *ff = file->private_data;
|
||
|
struct inode *inode = file_inode(file);
|
||
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
||
|
struct fuse_mount *fm = ff->fm;
|
||
|
FUSE_ARGS(args);
|
||
|
struct fuse_fallocate_in inarg = {
|
||
|
.fh = ff->fh,
|
||
|
.offset = offset,
|
||
|
.length = length,
|
||
|
.mode = mode
|
||
|
};
|
||
|
int err;
|
||
|
bool block_faults = FUSE_IS_DAX(inode) &&
|
||
|
(!(mode & FALLOC_FL_KEEP_SIZE) ||
|
||
|
(mode & (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE)));
|
||
|
|
||
|
if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
|
||
|
FALLOC_FL_ZERO_RANGE))
|
||
|
return -EOPNOTSUPP;
|
||
|
|
||
|
if (fm->fc->no_fallocate)
|
||
|
return -EOPNOTSUPP;
|
||
|
|
||
|
inode_lock(inode);
|
||
|
if (block_faults) {
|
||
|
filemap_invalidate_lock(inode->i_mapping);
|
||
|
err = fuse_dax_break_layouts(inode, 0, 0);
|
||
|
if (err)
|
||
|
goto out;
|
||
|
}
|
||
|
|
||
|
if (mode & (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE)) {
|
||
|
loff_t endbyte = offset + length - 1;
|
||
|
|
||
|
err = fuse_writeback_range(inode, offset, endbyte);
|
||
|
if (err)
|
||
|
goto out;
|
||
|
}
|
||
|
|
||
|
if (!(mode & FALLOC_FL_KEEP_SIZE) &&
|
||
|
offset + length > i_size_read(inode)) {
|
||
|
err = inode_newsize_ok(inode, offset + length);
|
||
|
if (err)
|
||
|
goto out;
|
||
|
}
|
||
|
|
||
|
err = file_modified(file);
|
||
|
if (err)
|
||
|
goto out;
|
||
|
|
||
|
if (!(mode & FALLOC_FL_KEEP_SIZE))
|
||
|
set_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
|
||
|
|
||
|
args.opcode = FUSE_FALLOCATE;
|
||
|
args.nodeid = ff->nodeid;
|
||
|
args.in_numargs = 1;
|
||
|
args.in_args[0].size = sizeof(inarg);
|
||
|
args.in_args[0].value = &inarg;
|
||
|
err = fuse_simple_request(fm, &args);
|
||
|
if (err == -ENOSYS) {
|
||
|
fm->fc->no_fallocate = 1;
|
||
|
err = -EOPNOTSUPP;
|
||
|
}
|
||
|
if (err)
|
||
|
goto out;
|
||
|
|
||
|
/* we could have extended the file */
|
||
|
if (!(mode & FALLOC_FL_KEEP_SIZE)) {
|
||
|
if (fuse_write_update_attr(inode, offset + length, length))
|
||
|
file_update_time(file);
|
||
|
}
|
||
|
|
||
|
if (mode & (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE))
|
||
|
truncate_pagecache_range(inode, offset, offset + length - 1);
|
||
|
|
||
|
fuse_invalidate_attr_mask(inode, FUSE_STATX_MODSIZE);
|
||
|
|
||
|
out:
|
||
|
if (!(mode & FALLOC_FL_KEEP_SIZE))
|
||
|
clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
|
||
|
|
||
|
if (block_faults)
|
||
|
filemap_invalidate_unlock(inode->i_mapping);
|
||
|
|
||
|
inode_unlock(inode);
|
||
|
|
||
|
fuse_flush_time_update(inode);
|
||
|
|
||
|
return err;
|
||
|
}
|
||
|
|
||
|
static ssize_t __fuse_copy_file_range(struct file *file_in, loff_t pos_in,
|
||
|
struct file *file_out, loff_t pos_out,
|
||
|
size_t len, unsigned int flags)
|
||
|
{
|
||
|
struct fuse_file *ff_in = file_in->private_data;
|
||
|
struct fuse_file *ff_out = file_out->private_data;
|
||
|
struct inode *inode_in = file_inode(file_in);
|
||
|
struct inode *inode_out = file_inode(file_out);
|
||
|
struct fuse_inode *fi_out = get_fuse_inode(inode_out);
|
||
|
struct fuse_mount *fm = ff_in->fm;
|
||
|
struct fuse_conn *fc = fm->fc;
|
||
|
FUSE_ARGS(args);
|
||
|
struct fuse_copy_file_range_in inarg = {
|
||
|
.fh_in = ff_in->fh,
|
||
|
.off_in = pos_in,
|
||
|
.nodeid_out = ff_out->nodeid,
|
||
|
.fh_out = ff_out->fh,
|
||
|
.off_out = pos_out,
|
||
|
.len = len,
|
||
|
.flags = flags
|
||
|
};
|
||
|
struct fuse_write_out outarg;
|
||
|
ssize_t err;
|
||
|
/* mark unstable when write-back is not used, and file_out gets
|
||
|
* extended */
|
||
|
bool is_unstable = (!fc->writeback_cache) &&
|
||
|
((pos_out + len) > inode_out->i_size);
|
||
|
|
||
|
if (fc->no_copy_file_range)
|
||
|
return -EOPNOTSUPP;
|
||
|
|
||
|
if (file_inode(file_in)->i_sb != file_inode(file_out)->i_sb)
|
||
|
return -EXDEV;
|
||
|
|
||
|
inode_lock(inode_in);
|
||
|
err = fuse_writeback_range(inode_in, pos_in, pos_in + len - 1);
|
||
|
inode_unlock(inode_in);
|
||
|
if (err)
|
||
|
return err;
|
||
|
|
||
|
inode_lock(inode_out);
|
||
|
|
||
|
err = file_modified(file_out);
|
||
|
if (err)
|
||
|
goto out;
|
||
|
|
||
|
/*
|
||
|
* Write out dirty pages in the destination file before sending the COPY
|
||
|
* request to userspace. After the request is completed, truncate off
|
||
|
* pages (including partial ones) from the cache that have been copied,
|
||
|
* since these contain stale data at that point.
|
||
|
*
|
||
|
* This should be mostly correct, but if the COPY writes to partial
|
||
|
* pages (at the start or end) and the parts not covered by the COPY are
|
||
|
* written through a memory map after calling fuse_writeback_range(),
|
||
|
* then these partial page modifications will be lost on truncation.
|
||
|
*
|
||
|
* It is unlikely that someone would rely on such mixed style
|
||
|
* modifications. Yet this does give less guarantees than if the
|
||
|
* copying was performed with write(2).
|
||
|
*
|
||
|
* To fix this a mapping->invalidate_lock could be used to prevent new
|
||
|
* faults while the copy is ongoing.
|
||
|
*/
|
||
|
err = fuse_writeback_range(inode_out, pos_out, pos_out + len - 1);
|
||
|
if (err)
|
||
|
goto out;
|
||
|
|
||
|
if (is_unstable)
|
||
|
set_bit(FUSE_I_SIZE_UNSTABLE, &fi_out->state);
|
||
|
|
||
|
args.opcode = FUSE_COPY_FILE_RANGE;
|
||
|
args.nodeid = ff_in->nodeid;
|
||
|
args.in_numargs = 1;
|
||
|
args.in_args[0].size = sizeof(inarg);
|
||
|
args.in_args[0].value = &inarg;
|
||
|
args.out_numargs = 1;
|
||
|
args.out_args[0].size = sizeof(outarg);
|
||
|
args.out_args[0].value = &outarg;
|
||
|
err = fuse_simple_request(fm, &args);
|
||
|
if (err == -ENOSYS) {
|
||
|
fc->no_copy_file_range = 1;
|
||
|
err = -EOPNOTSUPP;
|
||
|
}
|
||
|
if (err)
|
||
|
goto out;
|
||
|
|
||
|
truncate_inode_pages_range(inode_out->i_mapping,
|
||
|
ALIGN_DOWN(pos_out, PAGE_SIZE),
|
||
|
ALIGN(pos_out + outarg.size, PAGE_SIZE) - 1);
|
||
|
|
||
|
file_update_time(file_out);
|
||
|
fuse_write_update_attr(inode_out, pos_out + outarg.size, outarg.size);
|
||
|
|
||
|
err = outarg.size;
|
||
|
out:
|
||
|
if (is_unstable)
|
||
|
clear_bit(FUSE_I_SIZE_UNSTABLE, &fi_out->state);
|
||
|
|
||
|
inode_unlock(inode_out);
|
||
|
file_accessed(file_in);
|
||
|
|
||
|
fuse_flush_time_update(inode_out);
|
||
|
|
||
|
return err;
|
||
|
}
|
||
|
|
||
|
static ssize_t fuse_copy_file_range(struct file *src_file, loff_t src_off,
|
||
|
struct file *dst_file, loff_t dst_off,
|
||
|
size_t len, unsigned int flags)
|
||
|
{
|
||
|
ssize_t ret;
|
||
|
|
||
|
ret = __fuse_copy_file_range(src_file, src_off, dst_file, dst_off,
|
||
|
len, flags);
|
||
|
|
||
|
if (ret == -EOPNOTSUPP || ret == -EXDEV)
|
||
|
ret = generic_copy_file_range(src_file, src_off, dst_file,
|
||
|
dst_off, len, flags);
|
||
|
return ret;
|
||
|
}
|
||
|
|
||
|
static const struct file_operations fuse_file_operations = {
|
||
|
.llseek = fuse_file_llseek,
|
||
|
.read_iter = fuse_file_read_iter,
|
||
|
.write_iter = fuse_file_write_iter,
|
||
|
.mmap = fuse_file_mmap,
|
||
|
.open = fuse_open,
|
||
|
.flush = fuse_flush,
|
||
|
.release = fuse_release,
|
||
|
.fsync = fuse_fsync,
|
||
|
.lock = fuse_file_lock,
|
||
|
.get_unmapped_area = thp_get_unmapped_area,
|
||
|
.flock = fuse_file_flock,
|
||
|
.splice_read = generic_file_splice_read,
|
||
|
.splice_write = iter_file_splice_write,
|
||
|
.unlocked_ioctl = fuse_file_ioctl,
|
||
|
.compat_ioctl = fuse_file_compat_ioctl,
|
||
|
.poll = fuse_file_poll,
|
||
|
.fallocate = fuse_file_fallocate,
|
||
|
.copy_file_range = fuse_copy_file_range,
|
||
|
};
|
||
|
|
||
|
static const struct address_space_operations fuse_file_aops = {
|
||
|
.read_folio = fuse_read_folio,
|
||
|
.readahead = fuse_readahead,
|
||
|
.writepage = fuse_writepage,
|
||
|
.writepages = fuse_writepages,
|
||
|
.launder_folio = fuse_launder_folio,
|
||
|
.dirty_folio = filemap_dirty_folio,
|
||
|
.bmap = fuse_bmap,
|
||
|
.direct_IO = fuse_direct_IO,
|
||
|
.write_begin = fuse_write_begin,
|
||
|
.write_end = fuse_write_end,
|
||
|
};
|
||
|
|
||
|
void fuse_init_file_inode(struct inode *inode, unsigned int flags)
|
||
|
{
|
||
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
||
|
|
||
|
inode->i_fop = &fuse_file_operations;
|
||
|
inode->i_data.a_ops = &fuse_file_aops;
|
||
|
|
||
|
INIT_LIST_HEAD(&fi->write_files);
|
||
|
INIT_LIST_HEAD(&fi->queued_writes);
|
||
|
fi->writectr = 0;
|
||
|
init_waitqueue_head(&fi->page_waitq);
|
||
|
fi->writepages = RB_ROOT;
|
||
|
|
||
|
if (IS_ENABLED(CONFIG_FUSE_DAX))
|
||
|
fuse_dax_inode_init(inode, flags);
|
||
|
}
|