![Linus Torvalds](/assets/img/avatar_default.png)
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: fuse: add fusectl interface to max_background fuse: limit user-specified values of max background requests fuse: use drop_nlink() instead of direct nlink manipulation fuse: document protocol version negotiation fuse: make the number of max background requests and congestion threshold tunable
1257 lines
28 KiB
C
1257 lines
28 KiB
C
/*
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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/file.h>
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#include <linux/seq_file.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/parser.h>
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#include <linux/statfs.h>
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#include <linux/random.h>
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#include <linux/sched.h>
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#include <linux/exportfs.h>
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MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
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MODULE_DESCRIPTION("Filesystem in Userspace");
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MODULE_LICENSE("GPL");
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static struct kmem_cache *fuse_inode_cachep;
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struct list_head fuse_conn_list;
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DEFINE_MUTEX(fuse_mutex);
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static int set_global_limit(const char *val, struct kernel_param *kp);
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unsigned max_user_bgreq;
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module_param_call(max_user_bgreq, set_global_limit, param_get_uint,
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&max_user_bgreq, 0644);
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__MODULE_PARM_TYPE(max_user_bgreq, "uint");
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MODULE_PARM_DESC(max_user_bgreq,
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"Global limit for the maximum number of backgrounded requests an "
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"unprivileged user can set");
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unsigned max_user_congthresh;
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module_param_call(max_user_congthresh, set_global_limit, param_get_uint,
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&max_user_congthresh, 0644);
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__MODULE_PARM_TYPE(max_user_congthresh, "uint");
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MODULE_PARM_DESC(max_user_congthresh,
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"Global limit for the maximum congestion threshold an "
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"unprivileged user can set");
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#define FUSE_SUPER_MAGIC 0x65735546
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#define FUSE_DEFAULT_BLKSIZE 512
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/** Maximum number of outstanding background requests */
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#define FUSE_DEFAULT_MAX_BACKGROUND 12
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/** Congestion starts at 75% of maximum */
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#define FUSE_DEFAULT_CONGESTION_THRESHOLD (FUSE_DEFAULT_MAX_BACKGROUND * 3 / 4)
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struct fuse_mount_data {
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int fd;
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unsigned rootmode;
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unsigned user_id;
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unsigned group_id;
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unsigned fd_present:1;
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unsigned rootmode_present:1;
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unsigned user_id_present:1;
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unsigned group_id_present:1;
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unsigned flags;
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unsigned max_read;
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unsigned blksize;
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};
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static struct inode *fuse_alloc_inode(struct super_block *sb)
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{
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struct inode *inode;
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struct fuse_inode *fi;
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inode = kmem_cache_alloc(fuse_inode_cachep, GFP_KERNEL);
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if (!inode)
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return NULL;
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fi = get_fuse_inode(inode);
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fi->i_time = 0;
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fi->nodeid = 0;
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fi->nlookup = 0;
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fi->attr_version = 0;
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fi->writectr = 0;
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INIT_LIST_HEAD(&fi->write_files);
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INIT_LIST_HEAD(&fi->queued_writes);
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INIT_LIST_HEAD(&fi->writepages);
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init_waitqueue_head(&fi->page_waitq);
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fi->forget_req = fuse_request_alloc();
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if (!fi->forget_req) {
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kmem_cache_free(fuse_inode_cachep, inode);
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return NULL;
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}
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return inode;
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}
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static void fuse_destroy_inode(struct inode *inode)
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{
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struct fuse_inode *fi = get_fuse_inode(inode);
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BUG_ON(!list_empty(&fi->write_files));
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BUG_ON(!list_empty(&fi->queued_writes));
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if (fi->forget_req)
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fuse_request_free(fi->forget_req);
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kmem_cache_free(fuse_inode_cachep, inode);
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}
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void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req,
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u64 nodeid, u64 nlookup)
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{
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struct fuse_forget_in *inarg = &req->misc.forget_in;
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inarg->nlookup = nlookup;
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req->in.h.opcode = FUSE_FORGET;
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req->in.h.nodeid = nodeid;
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req->in.numargs = 1;
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req->in.args[0].size = sizeof(struct fuse_forget_in);
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req->in.args[0].value = inarg;
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fuse_request_send_noreply(fc, req);
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}
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static void fuse_clear_inode(struct inode *inode)
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{
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if (inode->i_sb->s_flags & MS_ACTIVE) {
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struct fuse_conn *fc = get_fuse_conn(inode);
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struct fuse_inode *fi = get_fuse_inode(inode);
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fuse_send_forget(fc, fi->forget_req, fi->nodeid, fi->nlookup);
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fi->forget_req = NULL;
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}
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}
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static int fuse_remount_fs(struct super_block *sb, int *flags, char *data)
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{
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if (*flags & MS_MANDLOCK)
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return -EINVAL;
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return 0;
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}
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void fuse_truncate(struct address_space *mapping, loff_t offset)
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{
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/* See vmtruncate() */
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unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
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truncate_inode_pages(mapping, offset);
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unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
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}
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void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
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u64 attr_valid)
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{
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struct fuse_conn *fc = get_fuse_conn(inode);
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struct fuse_inode *fi = get_fuse_inode(inode);
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fi->attr_version = ++fc->attr_version;
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fi->i_time = attr_valid;
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inode->i_ino = attr->ino;
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inode->i_mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
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inode->i_nlink = attr->nlink;
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inode->i_uid = attr->uid;
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inode->i_gid = attr->gid;
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inode->i_blocks = attr->blocks;
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inode->i_atime.tv_sec = attr->atime;
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inode->i_atime.tv_nsec = attr->atimensec;
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inode->i_mtime.tv_sec = attr->mtime;
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inode->i_mtime.tv_nsec = attr->mtimensec;
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inode->i_ctime.tv_sec = attr->ctime;
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inode->i_ctime.tv_nsec = attr->ctimensec;
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if (attr->blksize != 0)
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inode->i_blkbits = ilog2(attr->blksize);
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else
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inode->i_blkbits = inode->i_sb->s_blocksize_bits;
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/*
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* Don't set the sticky bit in i_mode, unless we want the VFS
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* to check permissions. This prevents failures due to the
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* check in may_delete().
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*/
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fi->orig_i_mode = inode->i_mode;
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if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS))
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inode->i_mode &= ~S_ISVTX;
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}
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void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
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u64 attr_valid, u64 attr_version)
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{
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struct fuse_conn *fc = get_fuse_conn(inode);
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struct fuse_inode *fi = get_fuse_inode(inode);
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loff_t oldsize;
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spin_lock(&fc->lock);
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if (attr_version != 0 && fi->attr_version > attr_version) {
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spin_unlock(&fc->lock);
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return;
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}
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fuse_change_attributes_common(inode, attr, attr_valid);
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oldsize = inode->i_size;
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i_size_write(inode, attr->size);
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spin_unlock(&fc->lock);
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if (S_ISREG(inode->i_mode) && oldsize != attr->size) {
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if (attr->size < oldsize)
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fuse_truncate(inode->i_mapping, attr->size);
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invalidate_inode_pages2(inode->i_mapping);
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}
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}
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static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
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{
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inode->i_mode = attr->mode & S_IFMT;
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inode->i_size = attr->size;
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if (S_ISREG(inode->i_mode)) {
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fuse_init_common(inode);
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fuse_init_file_inode(inode);
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} else if (S_ISDIR(inode->i_mode))
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fuse_init_dir(inode);
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else if (S_ISLNK(inode->i_mode))
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fuse_init_symlink(inode);
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else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
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S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
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fuse_init_common(inode);
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init_special_inode(inode, inode->i_mode,
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new_decode_dev(attr->rdev));
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} else
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BUG();
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}
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int fuse_inode_eq(struct inode *inode, void *_nodeidp)
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{
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u64 nodeid = *(u64 *) _nodeidp;
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if (get_node_id(inode) == nodeid)
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return 1;
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else
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return 0;
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}
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static int fuse_inode_set(struct inode *inode, void *_nodeidp)
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{
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u64 nodeid = *(u64 *) _nodeidp;
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get_fuse_inode(inode)->nodeid = nodeid;
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return 0;
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}
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struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
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int generation, struct fuse_attr *attr,
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u64 attr_valid, u64 attr_version)
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{
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struct inode *inode;
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struct fuse_inode *fi;
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struct fuse_conn *fc = get_fuse_conn_super(sb);
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retry:
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inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
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if (!inode)
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return NULL;
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if ((inode->i_state & I_NEW)) {
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inode->i_flags |= S_NOATIME|S_NOCMTIME;
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inode->i_generation = generation;
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inode->i_data.backing_dev_info = &fc->bdi;
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fuse_init_inode(inode, attr);
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unlock_new_inode(inode);
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} else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
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/* Inode has changed type, any I/O on the old should fail */
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make_bad_inode(inode);
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iput(inode);
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goto retry;
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}
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fi = get_fuse_inode(inode);
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spin_lock(&fc->lock);
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fi->nlookup++;
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spin_unlock(&fc->lock);
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fuse_change_attributes(inode, attr, attr_valid, attr_version);
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return inode;
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}
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int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
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loff_t offset, loff_t len)
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{
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struct inode *inode;
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pgoff_t pg_start;
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pgoff_t pg_end;
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inode = ilookup5(sb, nodeid, fuse_inode_eq, &nodeid);
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if (!inode)
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return -ENOENT;
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fuse_invalidate_attr(inode);
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if (offset >= 0) {
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pg_start = offset >> PAGE_CACHE_SHIFT;
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if (len <= 0)
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pg_end = -1;
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else
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pg_end = (offset + len - 1) >> PAGE_CACHE_SHIFT;
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invalidate_inode_pages2_range(inode->i_mapping,
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pg_start, pg_end);
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}
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iput(inode);
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return 0;
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}
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static void fuse_umount_begin(struct super_block *sb)
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{
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fuse_abort_conn(get_fuse_conn_super(sb));
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}
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static void fuse_send_destroy(struct fuse_conn *fc)
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{
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struct fuse_req *req = fc->destroy_req;
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if (req && fc->conn_init) {
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fc->destroy_req = NULL;
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req->in.h.opcode = FUSE_DESTROY;
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req->force = 1;
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fuse_request_send(fc, req);
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fuse_put_request(fc, req);
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}
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}
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static void fuse_bdi_destroy(struct fuse_conn *fc)
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{
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if (fc->bdi_initialized)
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bdi_destroy(&fc->bdi);
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}
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void fuse_conn_kill(struct fuse_conn *fc)
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{
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spin_lock(&fc->lock);
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fc->connected = 0;
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fc->blocked = 0;
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spin_unlock(&fc->lock);
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/* Flush all readers on this fs */
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kill_fasync(&fc->fasync, SIGIO, POLL_IN);
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wake_up_all(&fc->waitq);
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wake_up_all(&fc->blocked_waitq);
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wake_up_all(&fc->reserved_req_waitq);
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mutex_lock(&fuse_mutex);
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list_del(&fc->entry);
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fuse_ctl_remove_conn(fc);
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mutex_unlock(&fuse_mutex);
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fuse_bdi_destroy(fc);
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}
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EXPORT_SYMBOL_GPL(fuse_conn_kill);
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static void fuse_put_super(struct super_block *sb)
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{
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struct fuse_conn *fc = get_fuse_conn_super(sb);
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fuse_send_destroy(fc);
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fuse_conn_kill(fc);
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fuse_conn_put(fc);
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}
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static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
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{
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stbuf->f_type = FUSE_SUPER_MAGIC;
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stbuf->f_bsize = attr->bsize;
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stbuf->f_frsize = attr->frsize;
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stbuf->f_blocks = attr->blocks;
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stbuf->f_bfree = attr->bfree;
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stbuf->f_bavail = attr->bavail;
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stbuf->f_files = attr->files;
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stbuf->f_ffree = attr->ffree;
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stbuf->f_namelen = attr->namelen;
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/* fsid is left zero */
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}
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static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
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{
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struct super_block *sb = dentry->d_sb;
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struct fuse_conn *fc = get_fuse_conn_super(sb);
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struct fuse_req *req;
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struct fuse_statfs_out outarg;
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int err;
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if (!fuse_allow_task(fc, current)) {
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buf->f_type = FUSE_SUPER_MAGIC;
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return 0;
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}
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req = fuse_get_req(fc);
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if (IS_ERR(req))
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return PTR_ERR(req);
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memset(&outarg, 0, sizeof(outarg));
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req->in.numargs = 0;
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req->in.h.opcode = FUSE_STATFS;
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req->in.h.nodeid = get_node_id(dentry->d_inode);
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req->out.numargs = 1;
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req->out.args[0].size =
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fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg);
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req->out.args[0].value = &outarg;
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fuse_request_send(fc, req);
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err = req->out.h.error;
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if (!err)
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convert_fuse_statfs(buf, &outarg.st);
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fuse_put_request(fc, req);
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return err;
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}
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enum {
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OPT_FD,
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OPT_ROOTMODE,
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OPT_USER_ID,
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OPT_GROUP_ID,
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OPT_DEFAULT_PERMISSIONS,
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OPT_ALLOW_OTHER,
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OPT_MAX_READ,
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OPT_BLKSIZE,
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OPT_ERR
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};
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static const match_table_t tokens = {
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{OPT_FD, "fd=%u"},
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{OPT_ROOTMODE, "rootmode=%o"},
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{OPT_USER_ID, "user_id=%u"},
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{OPT_GROUP_ID, "group_id=%u"},
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{OPT_DEFAULT_PERMISSIONS, "default_permissions"},
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{OPT_ALLOW_OTHER, "allow_other"},
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{OPT_MAX_READ, "max_read=%u"},
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{OPT_BLKSIZE, "blksize=%u"},
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{OPT_ERR, NULL}
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};
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static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
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{
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char *p;
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memset(d, 0, sizeof(struct fuse_mount_data));
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d->max_read = ~0;
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d->blksize = FUSE_DEFAULT_BLKSIZE;
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while ((p = strsep(&opt, ",")) != NULL) {
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int token;
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int value;
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substring_t args[MAX_OPT_ARGS];
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if (!*p)
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continue;
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token = match_token(p, tokens, args);
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switch (token) {
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case OPT_FD:
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if (match_int(&args[0], &value))
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return 0;
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d->fd = value;
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d->fd_present = 1;
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break;
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case OPT_ROOTMODE:
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if (match_octal(&args[0], &value))
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return 0;
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if (!fuse_valid_type(value))
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return 0;
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d->rootmode = value;
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d->rootmode_present = 1;
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break;
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case OPT_USER_ID:
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if (match_int(&args[0], &value))
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return 0;
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d->user_id = value;
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d->user_id_present = 1;
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break;
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case OPT_GROUP_ID:
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if (match_int(&args[0], &value))
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return 0;
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d->group_id = value;
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d->group_id_present = 1;
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break;
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case OPT_DEFAULT_PERMISSIONS:
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d->flags |= FUSE_DEFAULT_PERMISSIONS;
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break;
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case OPT_ALLOW_OTHER:
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d->flags |= FUSE_ALLOW_OTHER;
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break;
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|
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case OPT_MAX_READ:
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if (match_int(&args[0], &value))
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return 0;
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d->max_read = value;
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break;
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case OPT_BLKSIZE:
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if (!is_bdev || match_int(&args[0], &value))
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return 0;
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d->blksize = value;
|
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break;
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|
|
default:
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
if (!d->fd_present || !d->rootmode_present ||
|
|
!d->user_id_present || !d->group_id_present)
|
|
return 0;
|
|
|
|
return 1;
|
|
}
|
|
|
|
static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
|
|
{
|
|
struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb);
|
|
|
|
seq_printf(m, ",user_id=%u", fc->user_id);
|
|
seq_printf(m, ",group_id=%u", fc->group_id);
|
|
if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
|
|
seq_puts(m, ",default_permissions");
|
|
if (fc->flags & FUSE_ALLOW_OTHER)
|
|
seq_puts(m, ",allow_other");
|
|
if (fc->max_read != ~0)
|
|
seq_printf(m, ",max_read=%u", fc->max_read);
|
|
if (mnt->mnt_sb->s_bdev &&
|
|
mnt->mnt_sb->s_blocksize != FUSE_DEFAULT_BLKSIZE)
|
|
seq_printf(m, ",blksize=%lu", mnt->mnt_sb->s_blocksize);
|
|
return 0;
|
|
}
|
|
|
|
void fuse_conn_init(struct fuse_conn *fc)
|
|
{
|
|
memset(fc, 0, sizeof(*fc));
|
|
spin_lock_init(&fc->lock);
|
|
mutex_init(&fc->inst_mutex);
|
|
init_rwsem(&fc->killsb);
|
|
atomic_set(&fc->count, 1);
|
|
init_waitqueue_head(&fc->waitq);
|
|
init_waitqueue_head(&fc->blocked_waitq);
|
|
init_waitqueue_head(&fc->reserved_req_waitq);
|
|
INIT_LIST_HEAD(&fc->pending);
|
|
INIT_LIST_HEAD(&fc->processing);
|
|
INIT_LIST_HEAD(&fc->io);
|
|
INIT_LIST_HEAD(&fc->interrupts);
|
|
INIT_LIST_HEAD(&fc->bg_queue);
|
|
INIT_LIST_HEAD(&fc->entry);
|
|
atomic_set(&fc->num_waiting, 0);
|
|
fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND;
|
|
fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD;
|
|
fc->khctr = 0;
|
|
fc->polled_files = RB_ROOT;
|
|
fc->reqctr = 0;
|
|
fc->blocked = 1;
|
|
fc->attr_version = 1;
|
|
get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
|
|
}
|
|
EXPORT_SYMBOL_GPL(fuse_conn_init);
|
|
|
|
void fuse_conn_put(struct fuse_conn *fc)
|
|
{
|
|
if (atomic_dec_and_test(&fc->count)) {
|
|
if (fc->destroy_req)
|
|
fuse_request_free(fc->destroy_req);
|
|
mutex_destroy(&fc->inst_mutex);
|
|
fc->release(fc);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(fuse_conn_put);
|
|
|
|
struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
|
|
{
|
|
atomic_inc(&fc->count);
|
|
return fc;
|
|
}
|
|
EXPORT_SYMBOL_GPL(fuse_conn_get);
|
|
|
|
static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode)
|
|
{
|
|
struct fuse_attr attr;
|
|
memset(&attr, 0, sizeof(attr));
|
|
|
|
attr.mode = mode;
|
|
attr.ino = FUSE_ROOT_ID;
|
|
attr.nlink = 1;
|
|
return fuse_iget(sb, 1, 0, &attr, 0, 0);
|
|
}
|
|
|
|
struct fuse_inode_handle {
|
|
u64 nodeid;
|
|
u32 generation;
|
|
};
|
|
|
|
static struct dentry *fuse_get_dentry(struct super_block *sb,
|
|
struct fuse_inode_handle *handle)
|
|
{
|
|
struct fuse_conn *fc = get_fuse_conn_super(sb);
|
|
struct inode *inode;
|
|
struct dentry *entry;
|
|
int err = -ESTALE;
|
|
|
|
if (handle->nodeid == 0)
|
|
goto out_err;
|
|
|
|
inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid);
|
|
if (!inode) {
|
|
struct fuse_entry_out outarg;
|
|
struct qstr name;
|
|
|
|
if (!fc->export_support)
|
|
goto out_err;
|
|
|
|
name.len = 1;
|
|
name.name = ".";
|
|
err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg,
|
|
&inode);
|
|
if (err && err != -ENOENT)
|
|
goto out_err;
|
|
if (err || !inode) {
|
|
err = -ESTALE;
|
|
goto out_err;
|
|
}
|
|
err = -EIO;
|
|
if (get_node_id(inode) != handle->nodeid)
|
|
goto out_iput;
|
|
}
|
|
err = -ESTALE;
|
|
if (inode->i_generation != handle->generation)
|
|
goto out_iput;
|
|
|
|
entry = d_obtain_alias(inode);
|
|
if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID) {
|
|
entry->d_op = &fuse_dentry_operations;
|
|
fuse_invalidate_entry_cache(entry);
|
|
}
|
|
|
|
return entry;
|
|
|
|
out_iput:
|
|
iput(inode);
|
|
out_err:
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
static int fuse_encode_fh(struct dentry *dentry, u32 *fh, int *max_len,
|
|
int connectable)
|
|
{
|
|
struct inode *inode = dentry->d_inode;
|
|
bool encode_parent = connectable && !S_ISDIR(inode->i_mode);
|
|
int len = encode_parent ? 6 : 3;
|
|
u64 nodeid;
|
|
u32 generation;
|
|
|
|
if (*max_len < len)
|
|
return 255;
|
|
|
|
nodeid = get_fuse_inode(inode)->nodeid;
|
|
generation = inode->i_generation;
|
|
|
|
fh[0] = (u32)(nodeid >> 32);
|
|
fh[1] = (u32)(nodeid & 0xffffffff);
|
|
fh[2] = generation;
|
|
|
|
if (encode_parent) {
|
|
struct inode *parent;
|
|
|
|
spin_lock(&dentry->d_lock);
|
|
parent = dentry->d_parent->d_inode;
|
|
nodeid = get_fuse_inode(parent)->nodeid;
|
|
generation = parent->i_generation;
|
|
spin_unlock(&dentry->d_lock);
|
|
|
|
fh[3] = (u32)(nodeid >> 32);
|
|
fh[4] = (u32)(nodeid & 0xffffffff);
|
|
fh[5] = generation;
|
|
}
|
|
|
|
*max_len = len;
|
|
return encode_parent ? 0x82 : 0x81;
|
|
}
|
|
|
|
static struct dentry *fuse_fh_to_dentry(struct super_block *sb,
|
|
struct fid *fid, int fh_len, int fh_type)
|
|
{
|
|
struct fuse_inode_handle handle;
|
|
|
|
if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3)
|
|
return NULL;
|
|
|
|
handle.nodeid = (u64) fid->raw[0] << 32;
|
|
handle.nodeid |= (u64) fid->raw[1];
|
|
handle.generation = fid->raw[2];
|
|
return fuse_get_dentry(sb, &handle);
|
|
}
|
|
|
|
static struct dentry *fuse_fh_to_parent(struct super_block *sb,
|
|
struct fid *fid, int fh_len, int fh_type)
|
|
{
|
|
struct fuse_inode_handle parent;
|
|
|
|
if (fh_type != 0x82 || fh_len < 6)
|
|
return NULL;
|
|
|
|
parent.nodeid = (u64) fid->raw[3] << 32;
|
|
parent.nodeid |= (u64) fid->raw[4];
|
|
parent.generation = fid->raw[5];
|
|
return fuse_get_dentry(sb, &parent);
|
|
}
|
|
|
|
static struct dentry *fuse_get_parent(struct dentry *child)
|
|
{
|
|
struct inode *child_inode = child->d_inode;
|
|
struct fuse_conn *fc = get_fuse_conn(child_inode);
|
|
struct inode *inode;
|
|
struct dentry *parent;
|
|
struct fuse_entry_out outarg;
|
|
struct qstr name;
|
|
int err;
|
|
|
|
if (!fc->export_support)
|
|
return ERR_PTR(-ESTALE);
|
|
|
|
name.len = 2;
|
|
name.name = "..";
|
|
err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode),
|
|
&name, &outarg, &inode);
|
|
if (err) {
|
|
if (err == -ENOENT)
|
|
return ERR_PTR(-ESTALE);
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
parent = d_obtain_alias(inode);
|
|
if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID) {
|
|
parent->d_op = &fuse_dentry_operations;
|
|
fuse_invalidate_entry_cache(parent);
|
|
}
|
|
|
|
return parent;
|
|
}
|
|
|
|
static const struct export_operations fuse_export_operations = {
|
|
.fh_to_dentry = fuse_fh_to_dentry,
|
|
.fh_to_parent = fuse_fh_to_parent,
|
|
.encode_fh = fuse_encode_fh,
|
|
.get_parent = fuse_get_parent,
|
|
};
|
|
|
|
static const struct super_operations fuse_super_operations = {
|
|
.alloc_inode = fuse_alloc_inode,
|
|
.destroy_inode = fuse_destroy_inode,
|
|
.clear_inode = fuse_clear_inode,
|
|
.drop_inode = generic_delete_inode,
|
|
.remount_fs = fuse_remount_fs,
|
|
.put_super = fuse_put_super,
|
|
.umount_begin = fuse_umount_begin,
|
|
.statfs = fuse_statfs,
|
|
.show_options = fuse_show_options,
|
|
};
|
|
|
|
static void sanitize_global_limit(unsigned *limit)
|
|
{
|
|
if (*limit == 0)
|
|
*limit = ((num_physpages << PAGE_SHIFT) >> 13) /
|
|
sizeof(struct fuse_req);
|
|
|
|
if (*limit >= 1 << 16)
|
|
*limit = (1 << 16) - 1;
|
|
}
|
|
|
|
static int set_global_limit(const char *val, struct kernel_param *kp)
|
|
{
|
|
int rv;
|
|
|
|
rv = param_set_uint(val, kp);
|
|
if (rv)
|
|
return rv;
|
|
|
|
sanitize_global_limit((unsigned *)kp->arg);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg)
|
|
{
|
|
int cap_sys_admin = capable(CAP_SYS_ADMIN);
|
|
|
|
if (arg->minor < 13)
|
|
return;
|
|
|
|
sanitize_global_limit(&max_user_bgreq);
|
|
sanitize_global_limit(&max_user_congthresh);
|
|
|
|
if (arg->max_background) {
|
|
fc->max_background = arg->max_background;
|
|
|
|
if (!cap_sys_admin && fc->max_background > max_user_bgreq)
|
|
fc->max_background = max_user_bgreq;
|
|
}
|
|
if (arg->congestion_threshold) {
|
|
fc->congestion_threshold = arg->congestion_threshold;
|
|
|
|
if (!cap_sys_admin &&
|
|
fc->congestion_threshold > max_user_congthresh)
|
|
fc->congestion_threshold = max_user_congthresh;
|
|
}
|
|
}
|
|
|
|
static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
|
|
{
|
|
struct fuse_init_out *arg = &req->misc.init_out;
|
|
|
|
if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
|
|
fc->conn_error = 1;
|
|
else {
|
|
unsigned long ra_pages;
|
|
|
|
process_init_limits(fc, arg);
|
|
|
|
if (arg->minor >= 6) {
|
|
ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
|
|
if (arg->flags & FUSE_ASYNC_READ)
|
|
fc->async_read = 1;
|
|
if (!(arg->flags & FUSE_POSIX_LOCKS))
|
|
fc->no_lock = 1;
|
|
if (arg->flags & FUSE_ATOMIC_O_TRUNC)
|
|
fc->atomic_o_trunc = 1;
|
|
if (arg->minor >= 9) {
|
|
/* LOOKUP has dependency on proto version */
|
|
if (arg->flags & FUSE_EXPORT_SUPPORT)
|
|
fc->export_support = 1;
|
|
}
|
|
if (arg->flags & FUSE_BIG_WRITES)
|
|
fc->big_writes = 1;
|
|
if (arg->flags & FUSE_DONT_MASK)
|
|
fc->dont_mask = 1;
|
|
} else {
|
|
ra_pages = fc->max_read / PAGE_CACHE_SIZE;
|
|
fc->no_lock = 1;
|
|
}
|
|
|
|
fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
|
|
fc->minor = arg->minor;
|
|
fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
|
|
fc->max_write = max_t(unsigned, 4096, fc->max_write);
|
|
fc->conn_init = 1;
|
|
}
|
|
fc->blocked = 0;
|
|
wake_up_all(&fc->blocked_waitq);
|
|
}
|
|
|
|
static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
|
|
{
|
|
struct fuse_init_in *arg = &req->misc.init_in;
|
|
|
|
arg->major = FUSE_KERNEL_VERSION;
|
|
arg->minor = FUSE_KERNEL_MINOR_VERSION;
|
|
arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
|
|
arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC |
|
|
FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK;
|
|
req->in.h.opcode = FUSE_INIT;
|
|
req->in.numargs = 1;
|
|
req->in.args[0].size = sizeof(*arg);
|
|
req->in.args[0].value = arg;
|
|
req->out.numargs = 1;
|
|
/* Variable length arguement used for backward compatibility
|
|
with interface version < 7.5. Rest of init_out is zeroed
|
|
by do_get_request(), so a short reply is not a problem */
|
|
req->out.argvar = 1;
|
|
req->out.args[0].size = sizeof(struct fuse_init_out);
|
|
req->out.args[0].value = &req->misc.init_out;
|
|
req->end = process_init_reply;
|
|
fuse_request_send_background(fc, req);
|
|
}
|
|
|
|
static void fuse_free_conn(struct fuse_conn *fc)
|
|
{
|
|
kfree(fc);
|
|
}
|
|
|
|
static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
|
|
{
|
|
int err;
|
|
|
|
fc->bdi.name = "fuse";
|
|
fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
|
|
fc->bdi.unplug_io_fn = default_unplug_io_fn;
|
|
/* fuse does it's own writeback accounting */
|
|
fc->bdi.capabilities = BDI_CAP_NO_ACCT_WB;
|
|
|
|
err = bdi_init(&fc->bdi);
|
|
if (err)
|
|
return err;
|
|
|
|
fc->bdi_initialized = 1;
|
|
|
|
if (sb->s_bdev) {
|
|
err = bdi_register(&fc->bdi, NULL, "%u:%u-fuseblk",
|
|
MAJOR(fc->dev), MINOR(fc->dev));
|
|
} else {
|
|
err = bdi_register_dev(&fc->bdi, fc->dev);
|
|
}
|
|
|
|
if (err)
|
|
return err;
|
|
|
|
/*
|
|
* For a single fuse filesystem use max 1% of dirty +
|
|
* writeback threshold.
|
|
*
|
|
* This gives about 1M of write buffer for memory maps on a
|
|
* machine with 1G and 10% dirty_ratio, which should be more
|
|
* than enough.
|
|
*
|
|
* Privileged users can raise it by writing to
|
|
*
|
|
* /sys/class/bdi/<bdi>/max_ratio
|
|
*/
|
|
bdi_set_max_ratio(&fc->bdi, 1);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int fuse_fill_super(struct super_block *sb, void *data, int silent)
|
|
{
|
|
struct fuse_conn *fc;
|
|
struct inode *root;
|
|
struct fuse_mount_data d;
|
|
struct file *file;
|
|
struct dentry *root_dentry;
|
|
struct fuse_req *init_req;
|
|
int err;
|
|
int is_bdev = sb->s_bdev != NULL;
|
|
|
|
err = -EINVAL;
|
|
if (sb->s_flags & MS_MANDLOCK)
|
|
goto err;
|
|
|
|
if (!parse_fuse_opt((char *) data, &d, is_bdev))
|
|
goto err;
|
|
|
|
if (is_bdev) {
|
|
#ifdef CONFIG_BLOCK
|
|
err = -EINVAL;
|
|
if (!sb_set_blocksize(sb, d.blksize))
|
|
goto err;
|
|
#endif
|
|
} else {
|
|
sb->s_blocksize = PAGE_CACHE_SIZE;
|
|
sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
|
|
}
|
|
sb->s_magic = FUSE_SUPER_MAGIC;
|
|
sb->s_op = &fuse_super_operations;
|
|
sb->s_maxbytes = MAX_LFS_FILESIZE;
|
|
sb->s_export_op = &fuse_export_operations;
|
|
|
|
file = fget(d.fd);
|
|
err = -EINVAL;
|
|
if (!file)
|
|
goto err;
|
|
|
|
if (file->f_op != &fuse_dev_operations)
|
|
goto err_fput;
|
|
|
|
fc = kmalloc(sizeof(*fc), GFP_KERNEL);
|
|
err = -ENOMEM;
|
|
if (!fc)
|
|
goto err_fput;
|
|
|
|
fuse_conn_init(fc);
|
|
|
|
fc->dev = sb->s_dev;
|
|
fc->sb = sb;
|
|
err = fuse_bdi_init(fc, sb);
|
|
if (err)
|
|
goto err_put_conn;
|
|
|
|
sb->s_bdi = &fc->bdi;
|
|
|
|
/* Handle umasking inside the fuse code */
|
|
if (sb->s_flags & MS_POSIXACL)
|
|
fc->dont_mask = 1;
|
|
sb->s_flags |= MS_POSIXACL;
|
|
|
|
fc->release = fuse_free_conn;
|
|
fc->flags = d.flags;
|
|
fc->user_id = d.user_id;
|
|
fc->group_id = d.group_id;
|
|
fc->max_read = max_t(unsigned, 4096, d.max_read);
|
|
|
|
/* Used by get_root_inode() */
|
|
sb->s_fs_info = fc;
|
|
|
|
err = -ENOMEM;
|
|
root = fuse_get_root_inode(sb, d.rootmode);
|
|
if (!root)
|
|
goto err_put_conn;
|
|
|
|
root_dentry = d_alloc_root(root);
|
|
if (!root_dentry) {
|
|
iput(root);
|
|
goto err_put_conn;
|
|
}
|
|
|
|
init_req = fuse_request_alloc();
|
|
if (!init_req)
|
|
goto err_put_root;
|
|
|
|
if (is_bdev) {
|
|
fc->destroy_req = fuse_request_alloc();
|
|
if (!fc->destroy_req)
|
|
goto err_free_init_req;
|
|
}
|
|
|
|
mutex_lock(&fuse_mutex);
|
|
err = -EINVAL;
|
|
if (file->private_data)
|
|
goto err_unlock;
|
|
|
|
err = fuse_ctl_add_conn(fc);
|
|
if (err)
|
|
goto err_unlock;
|
|
|
|
list_add_tail(&fc->entry, &fuse_conn_list);
|
|
sb->s_root = root_dentry;
|
|
fc->connected = 1;
|
|
file->private_data = fuse_conn_get(fc);
|
|
mutex_unlock(&fuse_mutex);
|
|
/*
|
|
* atomic_dec_and_test() in fput() provides the necessary
|
|
* memory barrier for file->private_data to be visible on all
|
|
* CPUs after this
|
|
*/
|
|
fput(file);
|
|
|
|
fuse_send_init(fc, init_req);
|
|
|
|
return 0;
|
|
|
|
err_unlock:
|
|
mutex_unlock(&fuse_mutex);
|
|
err_free_init_req:
|
|
fuse_request_free(init_req);
|
|
err_put_root:
|
|
dput(root_dentry);
|
|
err_put_conn:
|
|
fuse_bdi_destroy(fc);
|
|
fuse_conn_put(fc);
|
|
err_fput:
|
|
fput(file);
|
|
err:
|
|
return err;
|
|
}
|
|
|
|
static int fuse_get_sb(struct file_system_type *fs_type,
|
|
int flags, const char *dev_name,
|
|
void *raw_data, struct vfsmount *mnt)
|
|
{
|
|
return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super, mnt);
|
|
}
|
|
|
|
static void fuse_kill_sb_anon(struct super_block *sb)
|
|
{
|
|
struct fuse_conn *fc = get_fuse_conn_super(sb);
|
|
|
|
if (fc) {
|
|
down_write(&fc->killsb);
|
|
fc->sb = NULL;
|
|
up_write(&fc->killsb);
|
|
}
|
|
|
|
kill_anon_super(sb);
|
|
}
|
|
|
|
static struct file_system_type fuse_fs_type = {
|
|
.owner = THIS_MODULE,
|
|
.name = "fuse",
|
|
.fs_flags = FS_HAS_SUBTYPE,
|
|
.get_sb = fuse_get_sb,
|
|
.kill_sb = fuse_kill_sb_anon,
|
|
};
|
|
|
|
#ifdef CONFIG_BLOCK
|
|
static int fuse_get_sb_blk(struct file_system_type *fs_type,
|
|
int flags, const char *dev_name,
|
|
void *raw_data, struct vfsmount *mnt)
|
|
{
|
|
return get_sb_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super,
|
|
mnt);
|
|
}
|
|
|
|
static void fuse_kill_sb_blk(struct super_block *sb)
|
|
{
|
|
struct fuse_conn *fc = get_fuse_conn_super(sb);
|
|
|
|
if (fc) {
|
|
down_write(&fc->killsb);
|
|
fc->sb = NULL;
|
|
up_write(&fc->killsb);
|
|
}
|
|
|
|
kill_block_super(sb);
|
|
}
|
|
|
|
static struct file_system_type fuseblk_fs_type = {
|
|
.owner = THIS_MODULE,
|
|
.name = "fuseblk",
|
|
.get_sb = fuse_get_sb_blk,
|
|
.kill_sb = fuse_kill_sb_blk,
|
|
.fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
|
|
};
|
|
|
|
static inline int register_fuseblk(void)
|
|
{
|
|
return register_filesystem(&fuseblk_fs_type);
|
|
}
|
|
|
|
static inline void unregister_fuseblk(void)
|
|
{
|
|
unregister_filesystem(&fuseblk_fs_type);
|
|
}
|
|
#else
|
|
static inline int register_fuseblk(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline void unregister_fuseblk(void)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
static void fuse_inode_init_once(void *foo)
|
|
{
|
|
struct inode *inode = foo;
|
|
|
|
inode_init_once(inode);
|
|
}
|
|
|
|
static int __init fuse_fs_init(void)
|
|
{
|
|
int err;
|
|
|
|
err = register_filesystem(&fuse_fs_type);
|
|
if (err)
|
|
goto out;
|
|
|
|
err = register_fuseblk();
|
|
if (err)
|
|
goto out_unreg;
|
|
|
|
fuse_inode_cachep = kmem_cache_create("fuse_inode",
|
|
sizeof(struct fuse_inode),
|
|
0, SLAB_HWCACHE_ALIGN,
|
|
fuse_inode_init_once);
|
|
err = -ENOMEM;
|
|
if (!fuse_inode_cachep)
|
|
goto out_unreg2;
|
|
|
|
return 0;
|
|
|
|
out_unreg2:
|
|
unregister_fuseblk();
|
|
out_unreg:
|
|
unregister_filesystem(&fuse_fs_type);
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
static void fuse_fs_cleanup(void)
|
|
{
|
|
unregister_filesystem(&fuse_fs_type);
|
|
unregister_fuseblk();
|
|
kmem_cache_destroy(fuse_inode_cachep);
|
|
}
|
|
|
|
static struct kobject *fuse_kobj;
|
|
static struct kobject *connections_kobj;
|
|
|
|
static int fuse_sysfs_init(void)
|
|
{
|
|
int err;
|
|
|
|
fuse_kobj = kobject_create_and_add("fuse", fs_kobj);
|
|
if (!fuse_kobj) {
|
|
err = -ENOMEM;
|
|
goto out_err;
|
|
}
|
|
|
|
connections_kobj = kobject_create_and_add("connections", fuse_kobj);
|
|
if (!connections_kobj) {
|
|
err = -ENOMEM;
|
|
goto out_fuse_unregister;
|
|
}
|
|
|
|
return 0;
|
|
|
|
out_fuse_unregister:
|
|
kobject_put(fuse_kobj);
|
|
out_err:
|
|
return err;
|
|
}
|
|
|
|
static void fuse_sysfs_cleanup(void)
|
|
{
|
|
kobject_put(connections_kobj);
|
|
kobject_put(fuse_kobj);
|
|
}
|
|
|
|
static int __init fuse_init(void)
|
|
{
|
|
int res;
|
|
|
|
printk(KERN_INFO "fuse init (API version %i.%i)\n",
|
|
FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
|
|
|
|
INIT_LIST_HEAD(&fuse_conn_list);
|
|
res = fuse_fs_init();
|
|
if (res)
|
|
goto err;
|
|
|
|
res = fuse_dev_init();
|
|
if (res)
|
|
goto err_fs_cleanup;
|
|
|
|
res = fuse_sysfs_init();
|
|
if (res)
|
|
goto err_dev_cleanup;
|
|
|
|
res = fuse_ctl_init();
|
|
if (res)
|
|
goto err_sysfs_cleanup;
|
|
|
|
sanitize_global_limit(&max_user_bgreq);
|
|
sanitize_global_limit(&max_user_congthresh);
|
|
|
|
return 0;
|
|
|
|
err_sysfs_cleanup:
|
|
fuse_sysfs_cleanup();
|
|
err_dev_cleanup:
|
|
fuse_dev_cleanup();
|
|
err_fs_cleanup:
|
|
fuse_fs_cleanup();
|
|
err:
|
|
return res;
|
|
}
|
|
|
|
static void __exit fuse_exit(void)
|
|
{
|
|
printk(KERN_DEBUG "fuse exit\n");
|
|
|
|
fuse_ctl_cleanup();
|
|
fuse_sysfs_cleanup();
|
|
fuse_fs_cleanup();
|
|
fuse_dev_cleanup();
|
|
}
|
|
|
|
module_init(fuse_init);
|
|
module_exit(fuse_exit);
|