![Miklos Szeredi](/assets/img/avatar_default.png)
If negative entries (nodeid == 0) were sent in reply to LOOKUP requests, two bugs could be triggered: - looking up a negative entry would return -EIO, - revaildate on an entry which turned negative would send a FORGET request with zero nodeid, which would cause an abort() in the library. The above would only happen if the 'negative_timeout=N' option was used, otherwise lookups reply -ENOENT, which worked correctly. Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
1219 lines
31 KiB
C
1219 lines
31 KiB
C
/*
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FUSE: Filesystem in Userspace
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Copyright (C) 2001-2005 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/file.h>
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#include <linux/gfp.h>
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#include <linux/sched.h>
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#include <linux/namei.h>
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/*
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* FUSE caches dentries and attributes with separate timeout. The
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* time in jiffies until the dentry/attributes are valid is stored in
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* dentry->d_time and fuse_inode->i_time respectively.
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*/
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/*
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* Calculate the time in jiffies until a dentry/attributes are valid
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*/
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static unsigned long time_to_jiffies(unsigned long sec, unsigned long nsec)
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{
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struct timespec ts = {sec, nsec};
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return jiffies + timespec_to_jiffies(&ts);
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}
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/*
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* Set dentry and possibly attribute timeouts from the lookup/mk*
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* replies
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*/
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static void fuse_change_timeout(struct dentry *entry, struct fuse_entry_out *o)
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{
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entry->d_time = time_to_jiffies(o->entry_valid, o->entry_valid_nsec);
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if (entry->d_inode)
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get_fuse_inode(entry->d_inode)->i_time =
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time_to_jiffies(o->attr_valid, o->attr_valid_nsec);
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}
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/*
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* Mark the attributes as stale, so that at the next call to
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* ->getattr() they will be fetched from userspace
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*/
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void fuse_invalidate_attr(struct inode *inode)
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{
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get_fuse_inode(inode)->i_time = jiffies - 1;
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}
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/*
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* Just mark the entry as stale, so that a next attempt to look it up
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* will result in a new lookup call to userspace
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*
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* This is called when a dentry is about to become negative and the
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* timeout is unknown (unlink, rmdir, rename and in some cases
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* lookup)
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*/
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static void fuse_invalidate_entry_cache(struct dentry *entry)
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{
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entry->d_time = jiffies - 1;
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}
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/*
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* Same as fuse_invalidate_entry_cache(), but also try to remove the
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* dentry from the hash
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*/
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static void fuse_invalidate_entry(struct dentry *entry)
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{
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d_invalidate(entry);
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fuse_invalidate_entry_cache(entry);
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}
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static void fuse_lookup_init(struct fuse_req *req, struct inode *dir,
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struct dentry *entry,
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struct fuse_entry_out *outarg)
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{
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req->in.h.opcode = FUSE_LOOKUP;
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req->in.h.nodeid = get_node_id(dir);
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req->inode = dir;
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req->in.numargs = 1;
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req->in.args[0].size = entry->d_name.len + 1;
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req->in.args[0].value = entry->d_name.name;
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req->out.numargs = 1;
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req->out.args[0].size = sizeof(struct fuse_entry_out);
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req->out.args[0].value = outarg;
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}
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/*
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* Check whether the dentry is still valid
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*
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* If the entry validity timeout has expired and the dentry is
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* positive, try to redo the lookup. If the lookup results in a
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* different inode, then let the VFS invalidate the dentry and redo
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* the lookup once more. If the lookup results in the same inode,
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* then refresh the attributes, timeouts and mark the dentry valid.
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*/
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static int fuse_dentry_revalidate(struct dentry *entry, struct nameidata *nd)
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{
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struct inode *inode = entry->d_inode;
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if (inode && is_bad_inode(inode))
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return 0;
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else if (time_after(jiffies, entry->d_time)) {
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int err;
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struct fuse_entry_out outarg;
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struct fuse_conn *fc;
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struct fuse_req *req;
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/* Doesn't hurt to "reset" the validity timeout */
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fuse_invalidate_entry_cache(entry);
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/* For negative dentries, always do a fresh lookup */
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if (!inode)
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return 0;
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fc = get_fuse_conn(inode);
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req = fuse_get_request(fc);
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if (!req)
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return 0;
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fuse_lookup_init(req, entry->d_parent->d_inode, entry, &outarg);
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request_send(fc, req);
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err = req->out.h.error;
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/* Zero nodeid is same as -ENOENT */
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if (!err && !outarg.nodeid)
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err = -ENOENT;
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if (!err) {
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struct fuse_inode *fi = get_fuse_inode(inode);
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if (outarg.nodeid != get_node_id(inode)) {
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fuse_send_forget(fc, req, outarg.nodeid, 1);
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return 0;
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}
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fi->nlookup ++;
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}
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fuse_put_request(fc, req);
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if (err || (outarg.attr.mode ^ inode->i_mode) & S_IFMT)
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return 0;
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fuse_change_attributes(inode, &outarg.attr);
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fuse_change_timeout(entry, &outarg);
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}
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return 1;
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}
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/*
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* Check if there's already a hashed alias of this directory inode.
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* If yes, then lookup and mkdir must not create a new alias.
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*/
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static int dir_alias(struct inode *inode)
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{
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if (S_ISDIR(inode->i_mode)) {
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struct dentry *alias = d_find_alias(inode);
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if (alias) {
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dput(alias);
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return 1;
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}
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}
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return 0;
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}
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static int invalid_nodeid(u64 nodeid)
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{
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return !nodeid || nodeid == FUSE_ROOT_ID;
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}
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static struct dentry_operations fuse_dentry_operations = {
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.d_revalidate = fuse_dentry_revalidate,
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};
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static int valid_mode(int m)
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{
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return S_ISREG(m) || S_ISDIR(m) || S_ISLNK(m) || S_ISCHR(m) ||
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S_ISBLK(m) || S_ISFIFO(m) || S_ISSOCK(m);
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}
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static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry,
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struct nameidata *nd)
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{
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int err;
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struct fuse_entry_out outarg;
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struct inode *inode = NULL;
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struct fuse_conn *fc = get_fuse_conn(dir);
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struct fuse_req *req;
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if (entry->d_name.len > FUSE_NAME_MAX)
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return ERR_PTR(-ENAMETOOLONG);
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req = fuse_get_request(fc);
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if (!req)
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return ERR_PTR(-EINTR);
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fuse_lookup_init(req, dir, entry, &outarg);
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request_send(fc, req);
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err = req->out.h.error;
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/* Zero nodeid is same as -ENOENT, but with valid timeout */
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if (!err && outarg.nodeid &&
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(invalid_nodeid(outarg.nodeid) || !valid_mode(outarg.attr.mode)))
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err = -EIO;
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if (!err && outarg.nodeid) {
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inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation,
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&outarg.attr);
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if (!inode) {
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fuse_send_forget(fc, req, outarg.nodeid, 1);
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return ERR_PTR(-ENOMEM);
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}
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}
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fuse_put_request(fc, req);
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if (err && err != -ENOENT)
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return ERR_PTR(err);
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if (inode && dir_alias(inode)) {
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iput(inode);
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return ERR_PTR(-EIO);
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}
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d_add(entry, inode);
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entry->d_op = &fuse_dentry_operations;
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if (!err)
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fuse_change_timeout(entry, &outarg);
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else
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fuse_invalidate_entry_cache(entry);
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return NULL;
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}
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/*
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* Atomic create+open operation
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*
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* If the filesystem doesn't support this, then fall back to separate
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* 'mknod' + 'open' requests.
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*/
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static int fuse_create_open(struct inode *dir, struct dentry *entry, int mode,
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struct nameidata *nd)
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{
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int err;
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struct inode *inode;
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struct fuse_conn *fc = get_fuse_conn(dir);
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struct fuse_req *req;
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struct fuse_open_in inarg;
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struct fuse_open_out outopen;
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struct fuse_entry_out outentry;
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struct fuse_file *ff;
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struct file *file;
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int flags = nd->intent.open.flags - 1;
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err = -ENOSYS;
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if (fc->no_create)
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goto out;
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err = -EINTR;
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req = fuse_get_request(fc);
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if (!req)
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goto out;
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ff = fuse_file_alloc();
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if (!ff)
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goto out_put_request;
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flags &= ~O_NOCTTY;
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memset(&inarg, 0, sizeof(inarg));
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inarg.flags = flags;
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inarg.mode = mode;
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req->in.h.opcode = FUSE_CREATE;
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req->in.h.nodeid = get_node_id(dir);
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req->inode = dir;
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req->in.numargs = 2;
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req->in.args[0].size = sizeof(inarg);
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req->in.args[0].value = &inarg;
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req->in.args[1].size = entry->d_name.len + 1;
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req->in.args[1].value = entry->d_name.name;
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req->out.numargs = 2;
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req->out.args[0].size = sizeof(outentry);
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req->out.args[0].value = &outentry;
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req->out.args[1].size = sizeof(outopen);
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req->out.args[1].value = &outopen;
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request_send(fc, req);
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err = req->out.h.error;
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if (err) {
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if (err == -ENOSYS)
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fc->no_create = 1;
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goto out_free_ff;
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}
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err = -EIO;
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if (!S_ISREG(outentry.attr.mode) || invalid_nodeid(outentry.nodeid))
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goto out_free_ff;
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inode = fuse_iget(dir->i_sb, outentry.nodeid, outentry.generation,
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&outentry.attr);
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err = -ENOMEM;
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if (!inode) {
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flags &= ~(O_CREAT | O_EXCL | O_TRUNC);
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ff->fh = outopen.fh;
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/* Special release, with inode = NULL, this will
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trigger a 'forget' request when the release is
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complete */
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fuse_send_release(fc, ff, outentry.nodeid, NULL, flags, 0);
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goto out_put_request;
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}
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fuse_put_request(fc, req);
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d_instantiate(entry, inode);
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fuse_change_timeout(entry, &outentry);
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file = lookup_instantiate_filp(nd, entry, generic_file_open);
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if (IS_ERR(file)) {
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ff->fh = outopen.fh;
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fuse_send_release(fc, ff, outentry.nodeid, inode, flags, 0);
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return PTR_ERR(file);
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}
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fuse_finish_open(inode, file, ff, &outopen);
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return 0;
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out_free_ff:
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fuse_file_free(ff);
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out_put_request:
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fuse_put_request(fc, req);
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out:
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return err;
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}
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/*
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* Code shared between mknod, mkdir, symlink and link
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*/
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static int create_new_entry(struct fuse_conn *fc, struct fuse_req *req,
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struct inode *dir, struct dentry *entry,
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int mode)
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{
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struct fuse_entry_out outarg;
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struct inode *inode;
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int err;
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req->in.h.nodeid = get_node_id(dir);
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req->inode = dir;
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req->out.numargs = 1;
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req->out.args[0].size = sizeof(outarg);
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req->out.args[0].value = &outarg;
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request_send(fc, req);
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err = req->out.h.error;
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if (err) {
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fuse_put_request(fc, req);
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return err;
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}
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err = -EIO;
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if (invalid_nodeid(outarg.nodeid))
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goto out_put_request;
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if ((outarg.attr.mode ^ mode) & S_IFMT)
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goto out_put_request;
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inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation,
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&outarg.attr);
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if (!inode) {
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fuse_send_forget(fc, req, outarg.nodeid, 1);
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return -ENOMEM;
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}
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fuse_put_request(fc, req);
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if (dir_alias(inode)) {
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iput(inode);
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return -EIO;
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}
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d_instantiate(entry, inode);
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fuse_change_timeout(entry, &outarg);
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fuse_invalidate_attr(dir);
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return 0;
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out_put_request:
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fuse_put_request(fc, req);
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return err;
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}
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static int fuse_mknod(struct inode *dir, struct dentry *entry, int mode,
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dev_t rdev)
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{
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struct fuse_mknod_in inarg;
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struct fuse_conn *fc = get_fuse_conn(dir);
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struct fuse_req *req = fuse_get_request(fc);
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if (!req)
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return -EINTR;
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memset(&inarg, 0, sizeof(inarg));
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inarg.mode = mode;
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inarg.rdev = new_encode_dev(rdev);
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req->in.h.opcode = FUSE_MKNOD;
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req->in.numargs = 2;
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req->in.args[0].size = sizeof(inarg);
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req->in.args[0].value = &inarg;
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req->in.args[1].size = entry->d_name.len + 1;
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req->in.args[1].value = entry->d_name.name;
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return create_new_entry(fc, req, dir, entry, mode);
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}
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static int fuse_create(struct inode *dir, struct dentry *entry, int mode,
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struct nameidata *nd)
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{
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if (nd && (nd->flags & LOOKUP_CREATE)) {
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int err = fuse_create_open(dir, entry, mode, nd);
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if (err != -ENOSYS)
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return err;
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/* Fall back on mknod */
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}
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return fuse_mknod(dir, entry, mode, 0);
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}
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static int fuse_mkdir(struct inode *dir, struct dentry *entry, int mode)
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{
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struct fuse_mkdir_in inarg;
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struct fuse_conn *fc = get_fuse_conn(dir);
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struct fuse_req *req = fuse_get_request(fc);
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if (!req)
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return -EINTR;
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memset(&inarg, 0, sizeof(inarg));
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inarg.mode = mode;
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req->in.h.opcode = FUSE_MKDIR;
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req->in.numargs = 2;
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req->in.args[0].size = sizeof(inarg);
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req->in.args[0].value = &inarg;
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req->in.args[1].size = entry->d_name.len + 1;
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req->in.args[1].value = entry->d_name.name;
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return create_new_entry(fc, req, dir, entry, S_IFDIR);
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}
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static int fuse_symlink(struct inode *dir, struct dentry *entry,
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const char *link)
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{
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struct fuse_conn *fc = get_fuse_conn(dir);
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unsigned len = strlen(link) + 1;
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struct fuse_req *req = fuse_get_request(fc);
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if (!req)
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return -EINTR;
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req->in.h.opcode = FUSE_SYMLINK;
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req->in.numargs = 2;
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req->in.args[0].size = entry->d_name.len + 1;
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req->in.args[0].value = entry->d_name.name;
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req->in.args[1].size = len;
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req->in.args[1].value = link;
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return create_new_entry(fc, req, dir, entry, S_IFLNK);
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}
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|
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static int fuse_unlink(struct inode *dir, struct dentry *entry)
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{
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int err;
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struct fuse_conn *fc = get_fuse_conn(dir);
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struct fuse_req *req = fuse_get_request(fc);
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if (!req)
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return -EINTR;
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req->in.h.opcode = FUSE_UNLINK;
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req->in.h.nodeid = get_node_id(dir);
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req->inode = dir;
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req->in.numargs = 1;
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req->in.args[0].size = entry->d_name.len + 1;
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req->in.args[0].value = entry->d_name.name;
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request_send(fc, req);
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err = req->out.h.error;
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fuse_put_request(fc, req);
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if (!err) {
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struct inode *inode = entry->d_inode;
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|
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/* Set nlink to zero so the inode can be cleared, if
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the inode does have more links this will be
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discovered at the next lookup/getattr */
|
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inode->i_nlink = 0;
|
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fuse_invalidate_attr(inode);
|
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fuse_invalidate_attr(dir);
|
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fuse_invalidate_entry_cache(entry);
|
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} else if (err == -EINTR)
|
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fuse_invalidate_entry(entry);
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return err;
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}
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|
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static int fuse_rmdir(struct inode *dir, struct dentry *entry)
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{
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int err;
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struct fuse_conn *fc = get_fuse_conn(dir);
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struct fuse_req *req = fuse_get_request(fc);
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if (!req)
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return -EINTR;
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|
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req->in.h.opcode = FUSE_RMDIR;
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req->in.h.nodeid = get_node_id(dir);
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req->inode = dir;
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req->in.numargs = 1;
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req->in.args[0].size = entry->d_name.len + 1;
|
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req->in.args[0].value = entry->d_name.name;
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request_send(fc, req);
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err = req->out.h.error;
|
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fuse_put_request(fc, req);
|
|
if (!err) {
|
|
entry->d_inode->i_nlink = 0;
|
|
fuse_invalidate_attr(dir);
|
|
fuse_invalidate_entry_cache(entry);
|
|
} else if (err == -EINTR)
|
|
fuse_invalidate_entry(entry);
|
|
return err;
|
|
}
|
|
|
|
static int fuse_rename(struct inode *olddir, struct dentry *oldent,
|
|
struct inode *newdir, struct dentry *newent)
|
|
{
|
|
int err;
|
|
struct fuse_rename_in inarg;
|
|
struct fuse_conn *fc = get_fuse_conn(olddir);
|
|
struct fuse_req *req = fuse_get_request(fc);
|
|
if (!req)
|
|
return -EINTR;
|
|
|
|
memset(&inarg, 0, sizeof(inarg));
|
|
inarg.newdir = get_node_id(newdir);
|
|
req->in.h.opcode = FUSE_RENAME;
|
|
req->in.h.nodeid = get_node_id(olddir);
|
|
req->inode = olddir;
|
|
req->inode2 = newdir;
|
|
req->in.numargs = 3;
|
|
req->in.args[0].size = sizeof(inarg);
|
|
req->in.args[0].value = &inarg;
|
|
req->in.args[1].size = oldent->d_name.len + 1;
|
|
req->in.args[1].value = oldent->d_name.name;
|
|
req->in.args[2].size = newent->d_name.len + 1;
|
|
req->in.args[2].value = newent->d_name.name;
|
|
request_send(fc, req);
|
|
err = req->out.h.error;
|
|
fuse_put_request(fc, req);
|
|
if (!err) {
|
|
fuse_invalidate_attr(olddir);
|
|
if (olddir != newdir)
|
|
fuse_invalidate_attr(newdir);
|
|
|
|
/* newent will end up negative */
|
|
if (newent->d_inode)
|
|
fuse_invalidate_entry_cache(newent);
|
|
} else if (err == -EINTR) {
|
|
/* If request was interrupted, DEITY only knows if the
|
|
rename actually took place. If the invalidation
|
|
fails (e.g. some process has CWD under the renamed
|
|
directory), then there can be inconsistency between
|
|
the dcache and the real filesystem. Tough luck. */
|
|
fuse_invalidate_entry(oldent);
|
|
if (newent->d_inode)
|
|
fuse_invalidate_entry(newent);
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
static int fuse_link(struct dentry *entry, struct inode *newdir,
|
|
struct dentry *newent)
|
|
{
|
|
int err;
|
|
struct fuse_link_in inarg;
|
|
struct inode *inode = entry->d_inode;
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_req *req = fuse_get_request(fc);
|
|
if (!req)
|
|
return -EINTR;
|
|
|
|
memset(&inarg, 0, sizeof(inarg));
|
|
inarg.oldnodeid = get_node_id(inode);
|
|
req->in.h.opcode = FUSE_LINK;
|
|
req->inode2 = inode;
|
|
req->in.numargs = 2;
|
|
req->in.args[0].size = sizeof(inarg);
|
|
req->in.args[0].value = &inarg;
|
|
req->in.args[1].size = newent->d_name.len + 1;
|
|
req->in.args[1].value = newent->d_name.name;
|
|
err = create_new_entry(fc, req, newdir, newent, inode->i_mode);
|
|
/* Contrary to "normal" filesystems it can happen that link
|
|
makes two "logical" inodes point to the same "physical"
|
|
inode. We invalidate the attributes of the old one, so it
|
|
will reflect changes in the backing inode (link count,
|
|
etc.)
|
|
*/
|
|
if (!err || err == -EINTR)
|
|
fuse_invalidate_attr(inode);
|
|
return err;
|
|
}
|
|
|
|
int fuse_do_getattr(struct inode *inode)
|
|
{
|
|
int err;
|
|
struct fuse_attr_out arg;
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_req *req = fuse_get_request(fc);
|
|
if (!req)
|
|
return -EINTR;
|
|
|
|
req->in.h.opcode = FUSE_GETATTR;
|
|
req->in.h.nodeid = get_node_id(inode);
|
|
req->inode = inode;
|
|
req->out.numargs = 1;
|
|
req->out.args[0].size = sizeof(arg);
|
|
req->out.args[0].value = &arg;
|
|
request_send(fc, req);
|
|
err = req->out.h.error;
|
|
fuse_put_request(fc, req);
|
|
if (!err) {
|
|
if ((inode->i_mode ^ arg.attr.mode) & S_IFMT) {
|
|
make_bad_inode(inode);
|
|
err = -EIO;
|
|
} else {
|
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
|
fuse_change_attributes(inode, &arg.attr);
|
|
fi->i_time = time_to_jiffies(arg.attr_valid,
|
|
arg.attr_valid_nsec);
|
|
}
|
|
}
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Calling into a user-controlled filesystem gives the filesystem
|
|
* daemon ptrace-like capabilities over the requester process. This
|
|
* means, that the filesystem daemon is able to record the exact
|
|
* filesystem operations performed, and can also control the behavior
|
|
* of the requester process in otherwise impossible ways. For example
|
|
* it can delay the operation for arbitrary length of time allowing
|
|
* DoS against the requester.
|
|
*
|
|
* For this reason only those processes can call into the filesystem,
|
|
* for which the owner of the mount has ptrace privilege. This
|
|
* excludes processes started by other users, suid or sgid processes.
|
|
*/
|
|
static int fuse_allow_task(struct fuse_conn *fc, struct task_struct *task)
|
|
{
|
|
if (fc->flags & FUSE_ALLOW_OTHER)
|
|
return 1;
|
|
|
|
if (task->euid == fc->user_id &&
|
|
task->suid == fc->user_id &&
|
|
task->uid == fc->user_id &&
|
|
task->egid == fc->group_id &&
|
|
task->sgid == fc->group_id &&
|
|
task->gid == fc->group_id)
|
|
return 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Check whether the inode attributes are still valid
|
|
*
|
|
* If the attribute validity timeout has expired, then fetch the fresh
|
|
* attributes with a 'getattr' request
|
|
*
|
|
* I'm not sure why cached attributes are never returned for the root
|
|
* inode, this is probably being too cautious.
|
|
*/
|
|
static int fuse_revalidate(struct dentry *entry)
|
|
{
|
|
struct inode *inode = entry->d_inode;
|
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
|
|
if (!fuse_allow_task(fc, current))
|
|
return -EACCES;
|
|
if (get_node_id(inode) != FUSE_ROOT_ID &&
|
|
time_before_eq(jiffies, fi->i_time))
|
|
return 0;
|
|
|
|
return fuse_do_getattr(inode);
|
|
}
|
|
|
|
static int fuse_access(struct inode *inode, int mask)
|
|
{
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_req *req;
|
|
struct fuse_access_in inarg;
|
|
int err;
|
|
|
|
if (fc->no_access)
|
|
return 0;
|
|
|
|
req = fuse_get_request(fc);
|
|
if (!req)
|
|
return -EINTR;
|
|
|
|
memset(&inarg, 0, sizeof(inarg));
|
|
inarg.mask = mask;
|
|
req->in.h.opcode = FUSE_ACCESS;
|
|
req->in.h.nodeid = get_node_id(inode);
|
|
req->inode = inode;
|
|
req->in.numargs = 1;
|
|
req->in.args[0].size = sizeof(inarg);
|
|
req->in.args[0].value = &inarg;
|
|
request_send(fc, req);
|
|
err = req->out.h.error;
|
|
fuse_put_request(fc, req);
|
|
if (err == -ENOSYS) {
|
|
fc->no_access = 1;
|
|
err = 0;
|
|
}
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Check permission. The two basic access models of FUSE are:
|
|
*
|
|
* 1) Local access checking ('default_permissions' mount option) based
|
|
* on file mode. This is the plain old disk filesystem permission
|
|
* modell.
|
|
*
|
|
* 2) "Remote" access checking, where server is responsible for
|
|
* checking permission in each inode operation. An exception to this
|
|
* is if ->permission() was invoked from sys_access() in which case an
|
|
* access request is sent. Execute permission is still checked
|
|
* locally based on file mode.
|
|
*/
|
|
static int fuse_permission(struct inode *inode, int mask, struct nameidata *nd)
|
|
{
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
|
|
if (!fuse_allow_task(fc, current))
|
|
return -EACCES;
|
|
else if (fc->flags & FUSE_DEFAULT_PERMISSIONS) {
|
|
int err = generic_permission(inode, mask, NULL);
|
|
|
|
/* If permission is denied, try to refresh file
|
|
attributes. This is also needed, because the root
|
|
node will at first have no permissions */
|
|
if (err == -EACCES) {
|
|
err = fuse_do_getattr(inode);
|
|
if (!err)
|
|
err = generic_permission(inode, mask, NULL);
|
|
}
|
|
|
|
/* Note: the opposite of the above test does not
|
|
exist. So if permissions are revoked this won't be
|
|
noticed immediately, only after the attribute
|
|
timeout has expired */
|
|
|
|
return err;
|
|
} else {
|
|
int mode = inode->i_mode;
|
|
if ((mask & MAY_EXEC) && !S_ISDIR(mode) && !(mode & S_IXUGO))
|
|
return -EACCES;
|
|
|
|
if (nd && (nd->flags & LOOKUP_ACCESS))
|
|
return fuse_access(inode, mask);
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
static int parse_dirfile(char *buf, size_t nbytes, struct file *file,
|
|
void *dstbuf, filldir_t filldir)
|
|
{
|
|
while (nbytes >= FUSE_NAME_OFFSET) {
|
|
struct fuse_dirent *dirent = (struct fuse_dirent *) buf;
|
|
size_t reclen = FUSE_DIRENT_SIZE(dirent);
|
|
int over;
|
|
if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX)
|
|
return -EIO;
|
|
if (reclen > nbytes)
|
|
break;
|
|
|
|
over = filldir(dstbuf, dirent->name, dirent->namelen,
|
|
file->f_pos, dirent->ino, dirent->type);
|
|
if (over)
|
|
break;
|
|
|
|
buf += reclen;
|
|
nbytes -= reclen;
|
|
file->f_pos = dirent->off;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int fuse_readdir(struct file *file, void *dstbuf, filldir_t filldir)
|
|
{
|
|
int err;
|
|
size_t nbytes;
|
|
struct page *page;
|
|
struct inode *inode = file->f_dentry->d_inode;
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_req *req;
|
|
|
|
if (is_bad_inode(inode))
|
|
return -EIO;
|
|
|
|
req = fuse_get_request(fc);
|
|
if (!req)
|
|
return -EINTR;
|
|
|
|
page = alloc_page(GFP_KERNEL);
|
|
if (!page) {
|
|
fuse_put_request(fc, req);
|
|
return -ENOMEM;
|
|
}
|
|
req->num_pages = 1;
|
|
req->pages[0] = page;
|
|
fuse_read_fill(req, file, inode, file->f_pos, PAGE_SIZE, FUSE_READDIR);
|
|
request_send(fc, req);
|
|
nbytes = req->out.args[0].size;
|
|
err = req->out.h.error;
|
|
fuse_put_request(fc, req);
|
|
if (!err)
|
|
err = parse_dirfile(page_address(page), nbytes, file, dstbuf,
|
|
filldir);
|
|
|
|
__free_page(page);
|
|
fuse_invalidate_attr(inode); /* atime changed */
|
|
return err;
|
|
}
|
|
|
|
static char *read_link(struct dentry *dentry)
|
|
{
|
|
struct inode *inode = dentry->d_inode;
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_req *req = fuse_get_request(fc);
|
|
char *link;
|
|
|
|
if (!req)
|
|
return ERR_PTR(-EINTR);
|
|
|
|
link = (char *) __get_free_page(GFP_KERNEL);
|
|
if (!link) {
|
|
link = ERR_PTR(-ENOMEM);
|
|
goto out;
|
|
}
|
|
req->in.h.opcode = FUSE_READLINK;
|
|
req->in.h.nodeid = get_node_id(inode);
|
|
req->inode = inode;
|
|
req->out.argvar = 1;
|
|
req->out.numargs = 1;
|
|
req->out.args[0].size = PAGE_SIZE - 1;
|
|
req->out.args[0].value = link;
|
|
request_send(fc, req);
|
|
if (req->out.h.error) {
|
|
free_page((unsigned long) link);
|
|
link = ERR_PTR(req->out.h.error);
|
|
} else
|
|
link[req->out.args[0].size] = '\0';
|
|
out:
|
|
fuse_put_request(fc, req);
|
|
fuse_invalidate_attr(inode); /* atime changed */
|
|
return link;
|
|
}
|
|
|
|
static void free_link(char *link)
|
|
{
|
|
if (!IS_ERR(link))
|
|
free_page((unsigned long) link);
|
|
}
|
|
|
|
static void *fuse_follow_link(struct dentry *dentry, struct nameidata *nd)
|
|
{
|
|
nd_set_link(nd, read_link(dentry));
|
|
return NULL;
|
|
}
|
|
|
|
static void fuse_put_link(struct dentry *dentry, struct nameidata *nd, void *c)
|
|
{
|
|
free_link(nd_get_link(nd));
|
|
}
|
|
|
|
static int fuse_dir_open(struct inode *inode, struct file *file)
|
|
{
|
|
return fuse_open_common(inode, file, 1);
|
|
}
|
|
|
|
static int fuse_dir_release(struct inode *inode, struct file *file)
|
|
{
|
|
return fuse_release_common(inode, file, 1);
|
|
}
|
|
|
|
static int fuse_dir_fsync(struct file *file, struct dentry *de, int datasync)
|
|
{
|
|
/* nfsd can call this with no file */
|
|
return file ? fuse_fsync_common(file, de, datasync, 1) : 0;
|
|
}
|
|
|
|
static void iattr_to_fattr(struct iattr *iattr, struct fuse_setattr_in *arg)
|
|
{
|
|
unsigned ivalid = iattr->ia_valid;
|
|
|
|
if (ivalid & ATTR_MODE)
|
|
arg->valid |= FATTR_MODE, arg->mode = iattr->ia_mode;
|
|
if (ivalid & ATTR_UID)
|
|
arg->valid |= FATTR_UID, arg->uid = iattr->ia_uid;
|
|
if (ivalid & ATTR_GID)
|
|
arg->valid |= FATTR_GID, arg->gid = iattr->ia_gid;
|
|
if (ivalid & ATTR_SIZE)
|
|
arg->valid |= FATTR_SIZE, arg->size = iattr->ia_size;
|
|
/* You can only _set_ these together (they may change by themselves) */
|
|
if ((ivalid & (ATTR_ATIME | ATTR_MTIME)) == (ATTR_ATIME | ATTR_MTIME)) {
|
|
arg->valid |= FATTR_ATIME | FATTR_MTIME;
|
|
arg->atime = iattr->ia_atime.tv_sec;
|
|
arg->mtime = iattr->ia_mtime.tv_sec;
|
|
}
|
|
if (ivalid & ATTR_FILE) {
|
|
struct fuse_file *ff = iattr->ia_file->private_data;
|
|
arg->valid |= FATTR_FH;
|
|
arg->fh = ff->fh;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Set attributes, and at the same time refresh them.
|
|
*
|
|
* Truncation is slightly complicated, because the 'truncate' request
|
|
* may fail, in which case we don't want to touch the mapping.
|
|
* vmtruncate() doesn't allow for this case. So do the rlimit
|
|
* checking by hand and call vmtruncate() only after the file has
|
|
* actually been truncated.
|
|
*/
|
|
static int fuse_setattr(struct dentry *entry, struct iattr *attr)
|
|
{
|
|
struct inode *inode = entry->d_inode;
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
|
struct fuse_req *req;
|
|
struct fuse_setattr_in inarg;
|
|
struct fuse_attr_out outarg;
|
|
int err;
|
|
int is_truncate = 0;
|
|
|
|
if (fc->flags & FUSE_DEFAULT_PERMISSIONS) {
|
|
err = inode_change_ok(inode, attr);
|
|
if (err)
|
|
return err;
|
|
}
|
|
|
|
if (attr->ia_valid & ATTR_SIZE) {
|
|
unsigned long limit;
|
|
is_truncate = 1;
|
|
limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
|
|
if (limit != RLIM_INFINITY && attr->ia_size > (loff_t) limit) {
|
|
send_sig(SIGXFSZ, current, 0);
|
|
return -EFBIG;
|
|
}
|
|
}
|
|
|
|
req = fuse_get_request(fc);
|
|
if (!req)
|
|
return -EINTR;
|
|
|
|
memset(&inarg, 0, sizeof(inarg));
|
|
iattr_to_fattr(attr, &inarg);
|
|
req->in.h.opcode = FUSE_SETATTR;
|
|
req->in.h.nodeid = get_node_id(inode);
|
|
req->inode = inode;
|
|
req->in.numargs = 1;
|
|
req->in.args[0].size = sizeof(inarg);
|
|
req->in.args[0].value = &inarg;
|
|
req->out.numargs = 1;
|
|
req->out.args[0].size = sizeof(outarg);
|
|
req->out.args[0].value = &outarg;
|
|
request_send(fc, req);
|
|
err = req->out.h.error;
|
|
fuse_put_request(fc, req);
|
|
if (!err) {
|
|
if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) {
|
|
make_bad_inode(inode);
|
|
err = -EIO;
|
|
} else {
|
|
if (is_truncate) {
|
|
loff_t origsize = i_size_read(inode);
|
|
i_size_write(inode, outarg.attr.size);
|
|
if (origsize > outarg.attr.size)
|
|
vmtruncate(inode, outarg.attr.size);
|
|
}
|
|
fuse_change_attributes(inode, &outarg.attr);
|
|
fi->i_time = time_to_jiffies(outarg.attr_valid,
|
|
outarg.attr_valid_nsec);
|
|
}
|
|
} else if (err == -EINTR)
|
|
fuse_invalidate_attr(inode);
|
|
|
|
return err;
|
|
}
|
|
|
|
static int fuse_getattr(struct vfsmount *mnt, struct dentry *entry,
|
|
struct kstat *stat)
|
|
{
|
|
struct inode *inode = entry->d_inode;
|
|
int err = fuse_revalidate(entry);
|
|
if (!err)
|
|
generic_fillattr(inode, stat);
|
|
|
|
return err;
|
|
}
|
|
|
|
static int fuse_setxattr(struct dentry *entry, const char *name,
|
|
const void *value, size_t size, int flags)
|
|
{
|
|
struct inode *inode = entry->d_inode;
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_req *req;
|
|
struct fuse_setxattr_in inarg;
|
|
int err;
|
|
|
|
if (fc->no_setxattr)
|
|
return -EOPNOTSUPP;
|
|
|
|
req = fuse_get_request(fc);
|
|
if (!req)
|
|
return -EINTR;
|
|
|
|
memset(&inarg, 0, sizeof(inarg));
|
|
inarg.size = size;
|
|
inarg.flags = flags;
|
|
req->in.h.opcode = FUSE_SETXATTR;
|
|
req->in.h.nodeid = get_node_id(inode);
|
|
req->inode = inode;
|
|
req->in.numargs = 3;
|
|
req->in.args[0].size = sizeof(inarg);
|
|
req->in.args[0].value = &inarg;
|
|
req->in.args[1].size = strlen(name) + 1;
|
|
req->in.args[1].value = name;
|
|
req->in.args[2].size = size;
|
|
req->in.args[2].value = value;
|
|
request_send(fc, req);
|
|
err = req->out.h.error;
|
|
fuse_put_request(fc, req);
|
|
if (err == -ENOSYS) {
|
|
fc->no_setxattr = 1;
|
|
err = -EOPNOTSUPP;
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static ssize_t fuse_getxattr(struct dentry *entry, const char *name,
|
|
void *value, size_t size)
|
|
{
|
|
struct inode *inode = entry->d_inode;
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_req *req;
|
|
struct fuse_getxattr_in inarg;
|
|
struct fuse_getxattr_out outarg;
|
|
ssize_t ret;
|
|
|
|
if (fc->no_getxattr)
|
|
return -EOPNOTSUPP;
|
|
|
|
req = fuse_get_request(fc);
|
|
if (!req)
|
|
return -EINTR;
|
|
|
|
memset(&inarg, 0, sizeof(inarg));
|
|
inarg.size = size;
|
|
req->in.h.opcode = FUSE_GETXATTR;
|
|
req->in.h.nodeid = get_node_id(inode);
|
|
req->inode = inode;
|
|
req->in.numargs = 2;
|
|
req->in.args[0].size = sizeof(inarg);
|
|
req->in.args[0].value = &inarg;
|
|
req->in.args[1].size = strlen(name) + 1;
|
|
req->in.args[1].value = name;
|
|
/* This is really two different operations rolled into one */
|
|
req->out.numargs = 1;
|
|
if (size) {
|
|
req->out.argvar = 1;
|
|
req->out.args[0].size = size;
|
|
req->out.args[0].value = value;
|
|
} else {
|
|
req->out.args[0].size = sizeof(outarg);
|
|
req->out.args[0].value = &outarg;
|
|
}
|
|
request_send(fc, req);
|
|
ret = req->out.h.error;
|
|
if (!ret)
|
|
ret = size ? req->out.args[0].size : outarg.size;
|
|
else {
|
|
if (ret == -ENOSYS) {
|
|
fc->no_getxattr = 1;
|
|
ret = -EOPNOTSUPP;
|
|
}
|
|
}
|
|
fuse_put_request(fc, req);
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size)
|
|
{
|
|
struct inode *inode = entry->d_inode;
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_req *req;
|
|
struct fuse_getxattr_in inarg;
|
|
struct fuse_getxattr_out outarg;
|
|
ssize_t ret;
|
|
|
|
if (fc->no_listxattr)
|
|
return -EOPNOTSUPP;
|
|
|
|
req = fuse_get_request(fc);
|
|
if (!req)
|
|
return -EINTR;
|
|
|
|
memset(&inarg, 0, sizeof(inarg));
|
|
inarg.size = size;
|
|
req->in.h.opcode = FUSE_LISTXATTR;
|
|
req->in.h.nodeid = get_node_id(inode);
|
|
req->inode = inode;
|
|
req->in.numargs = 1;
|
|
req->in.args[0].size = sizeof(inarg);
|
|
req->in.args[0].value = &inarg;
|
|
/* This is really two different operations rolled into one */
|
|
req->out.numargs = 1;
|
|
if (size) {
|
|
req->out.argvar = 1;
|
|
req->out.args[0].size = size;
|
|
req->out.args[0].value = list;
|
|
} else {
|
|
req->out.args[0].size = sizeof(outarg);
|
|
req->out.args[0].value = &outarg;
|
|
}
|
|
request_send(fc, req);
|
|
ret = req->out.h.error;
|
|
if (!ret)
|
|
ret = size ? req->out.args[0].size : outarg.size;
|
|
else {
|
|
if (ret == -ENOSYS) {
|
|
fc->no_listxattr = 1;
|
|
ret = -EOPNOTSUPP;
|
|
}
|
|
}
|
|
fuse_put_request(fc, req);
|
|
return ret;
|
|
}
|
|
|
|
static int fuse_removexattr(struct dentry *entry, const char *name)
|
|
{
|
|
struct inode *inode = entry->d_inode;
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_req *req;
|
|
int err;
|
|
|
|
if (fc->no_removexattr)
|
|
return -EOPNOTSUPP;
|
|
|
|
req = fuse_get_request(fc);
|
|
if (!req)
|
|
return -EINTR;
|
|
|
|
req->in.h.opcode = FUSE_REMOVEXATTR;
|
|
req->in.h.nodeid = get_node_id(inode);
|
|
req->inode = inode;
|
|
req->in.numargs = 1;
|
|
req->in.args[0].size = strlen(name) + 1;
|
|
req->in.args[0].value = name;
|
|
request_send(fc, req);
|
|
err = req->out.h.error;
|
|
fuse_put_request(fc, req);
|
|
if (err == -ENOSYS) {
|
|
fc->no_removexattr = 1;
|
|
err = -EOPNOTSUPP;
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static struct inode_operations fuse_dir_inode_operations = {
|
|
.lookup = fuse_lookup,
|
|
.mkdir = fuse_mkdir,
|
|
.symlink = fuse_symlink,
|
|
.unlink = fuse_unlink,
|
|
.rmdir = fuse_rmdir,
|
|
.rename = fuse_rename,
|
|
.link = fuse_link,
|
|
.setattr = fuse_setattr,
|
|
.create = fuse_create,
|
|
.mknod = fuse_mknod,
|
|
.permission = fuse_permission,
|
|
.getattr = fuse_getattr,
|
|
.setxattr = fuse_setxattr,
|
|
.getxattr = fuse_getxattr,
|
|
.listxattr = fuse_listxattr,
|
|
.removexattr = fuse_removexattr,
|
|
};
|
|
|
|
static struct file_operations fuse_dir_operations = {
|
|
.llseek = generic_file_llseek,
|
|
.read = generic_read_dir,
|
|
.readdir = fuse_readdir,
|
|
.open = fuse_dir_open,
|
|
.release = fuse_dir_release,
|
|
.fsync = fuse_dir_fsync,
|
|
};
|
|
|
|
static struct inode_operations fuse_common_inode_operations = {
|
|
.setattr = fuse_setattr,
|
|
.permission = fuse_permission,
|
|
.getattr = fuse_getattr,
|
|
.setxattr = fuse_setxattr,
|
|
.getxattr = fuse_getxattr,
|
|
.listxattr = fuse_listxattr,
|
|
.removexattr = fuse_removexattr,
|
|
};
|
|
|
|
static struct inode_operations fuse_symlink_inode_operations = {
|
|
.setattr = fuse_setattr,
|
|
.follow_link = fuse_follow_link,
|
|
.put_link = fuse_put_link,
|
|
.readlink = generic_readlink,
|
|
.getattr = fuse_getattr,
|
|
.setxattr = fuse_setxattr,
|
|
.getxattr = fuse_getxattr,
|
|
.listxattr = fuse_listxattr,
|
|
.removexattr = fuse_removexattr,
|
|
};
|
|
|
|
void fuse_init_common(struct inode *inode)
|
|
{
|
|
inode->i_op = &fuse_common_inode_operations;
|
|
}
|
|
|
|
void fuse_init_dir(struct inode *inode)
|
|
{
|
|
inode->i_op = &fuse_dir_inode_operations;
|
|
inode->i_fop = &fuse_dir_operations;
|
|
}
|
|
|
|
void fuse_init_symlink(struct inode *inode)
|
|
{
|
|
inode->i_op = &fuse_symlink_inode_operations;
|
|
}
|