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![Linus Torvalds](/assets/img/avatar_default.png)
Pull fuse update from Miklos Szeredi: "A bugfix and cleanups" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: fuse: release: private_data cannot be NULL fuse: cleanup fuse_file refcounting fuse: add missing FR_FORCE
1852 lines
45 KiB
C
1852 lines
45 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/file.h>
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#include <linux/sched.h>
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#include <linux/namei.h>
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#include <linux/slab.h>
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#include <linux/xattr.h>
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#include <linux/posix_acl.h>
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static bool fuse_use_readdirplus(struct inode *dir, struct dir_context *ctx)
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{
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struct fuse_conn *fc = get_fuse_conn(dir);
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struct fuse_inode *fi = get_fuse_inode(dir);
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if (!fc->do_readdirplus)
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return false;
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if (!fc->readdirplus_auto)
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return true;
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if (test_and_clear_bit(FUSE_I_ADVISE_RDPLUS, &fi->state))
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return true;
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if (ctx->pos == 0)
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return true;
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return false;
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}
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static void fuse_advise_use_readdirplus(struct inode *dir)
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{
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struct fuse_inode *fi = get_fuse_inode(dir);
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set_bit(FUSE_I_ADVISE_RDPLUS, &fi->state);
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}
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union fuse_dentry {
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u64 time;
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struct rcu_head rcu;
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};
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static inline void fuse_dentry_settime(struct dentry *entry, u64 time)
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{
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((union fuse_dentry *) entry->d_fsdata)->time = time;
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}
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static inline u64 fuse_dentry_time(struct dentry *entry)
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{
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return ((union fuse_dentry *) entry->d_fsdata)->time;
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}
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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_fsdata 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 u64 time_to_jiffies(u64 sec, u32 nsec)
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{
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if (sec || nsec) {
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struct timespec64 ts = {
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sec,
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min_t(u32, nsec, NSEC_PER_SEC - 1)
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};
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return get_jiffies_64() + timespec64_to_jiffies(&ts);
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} else
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return 0;
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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_entry_timeout(struct dentry *entry,
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struct fuse_entry_out *o)
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{
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fuse_dentry_settime(entry,
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time_to_jiffies(o->entry_valid, o->entry_valid_nsec));
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}
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static u64 attr_timeout(struct fuse_attr_out *o)
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{
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return time_to_jiffies(o->attr_valid, o->attr_valid_nsec);
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}
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static u64 entry_attr_timeout(struct fuse_entry_out *o)
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{
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return 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 = 0;
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}
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/**
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* Mark the attributes as stale due to an atime change. Avoid the invalidate if
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* atime is not used.
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*/
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void fuse_invalidate_atime(struct inode *inode)
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{
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if (!IS_RDONLY(inode))
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fuse_invalidate_attr(inode);
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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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void fuse_invalidate_entry_cache(struct dentry *entry)
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{
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fuse_dentry_settime(entry, 0);
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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_conn *fc, struct fuse_args *args,
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u64 nodeid, const struct qstr *name,
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struct fuse_entry_out *outarg)
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{
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memset(outarg, 0, sizeof(struct fuse_entry_out));
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args->in.h.opcode = FUSE_LOOKUP;
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args->in.h.nodeid = nodeid;
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args->in.numargs = 1;
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args->in.args[0].size = name->len + 1;
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args->in.args[0].value = name->name;
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args->out.numargs = 1;
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args->out.args[0].size = sizeof(struct fuse_entry_out);
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args->out.args[0].value = outarg;
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}
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u64 fuse_get_attr_version(struct fuse_conn *fc)
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{
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u64 curr_version;
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/*
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* The spin lock isn't actually needed on 64bit archs, but we
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* don't yet care too much about such optimizations.
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*/
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spin_lock(&fc->lock);
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curr_version = fc->attr_version;
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spin_unlock(&fc->lock);
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return curr_version;
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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, unsigned int flags)
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{
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struct inode *inode;
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struct dentry *parent;
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struct fuse_conn *fc;
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struct fuse_inode *fi;
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int ret;
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inode = d_inode_rcu(entry);
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if (inode && is_bad_inode(inode))
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goto invalid;
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else if (time_before64(fuse_dentry_time(entry), get_jiffies_64()) ||
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(flags & LOOKUP_REVAL)) {
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struct fuse_entry_out outarg;
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FUSE_ARGS(args);
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struct fuse_forget_link *forget;
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u64 attr_version;
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/* For negative dentries, always do a fresh lookup */
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if (!inode)
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goto invalid;
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ret = -ECHILD;
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if (flags & LOOKUP_RCU)
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goto out;
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fc = get_fuse_conn(inode);
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forget = fuse_alloc_forget();
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ret = -ENOMEM;
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if (!forget)
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goto out;
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attr_version = fuse_get_attr_version(fc);
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parent = dget_parent(entry);
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fuse_lookup_init(fc, &args, get_node_id(d_inode(parent)),
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&entry->d_name, &outarg);
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ret = fuse_simple_request(fc, &args);
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dput(parent);
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/* Zero nodeid is same as -ENOENT */
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if (!ret && !outarg.nodeid)
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ret = -ENOENT;
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if (!ret) {
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fi = get_fuse_inode(inode);
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if (outarg.nodeid != get_node_id(inode)) {
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fuse_queue_forget(fc, forget, outarg.nodeid, 1);
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goto invalid;
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}
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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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}
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kfree(forget);
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if (ret == -ENOMEM)
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goto out;
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if (ret || (outarg.attr.mode ^ inode->i_mode) & S_IFMT)
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goto invalid;
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forget_all_cached_acls(inode);
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fuse_change_attributes(inode, &outarg.attr,
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entry_attr_timeout(&outarg),
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attr_version);
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fuse_change_entry_timeout(entry, &outarg);
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} else if (inode) {
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fi = get_fuse_inode(inode);
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if (flags & LOOKUP_RCU) {
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if (test_bit(FUSE_I_INIT_RDPLUS, &fi->state))
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return -ECHILD;
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} else if (test_and_clear_bit(FUSE_I_INIT_RDPLUS, &fi->state)) {
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parent = dget_parent(entry);
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fuse_advise_use_readdirplus(d_inode(parent));
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dput(parent);
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}
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}
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ret = 1;
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out:
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return ret;
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invalid:
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ret = 0;
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goto out;
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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 int fuse_dentry_init(struct dentry *dentry)
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{
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dentry->d_fsdata = kzalloc(sizeof(union fuse_dentry), GFP_KERNEL);
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return dentry->d_fsdata ? 0 : -ENOMEM;
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}
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static void fuse_dentry_release(struct dentry *dentry)
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{
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union fuse_dentry *fd = dentry->d_fsdata;
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kfree_rcu(fd, rcu);
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}
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const struct dentry_operations fuse_dentry_operations = {
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.d_revalidate = fuse_dentry_revalidate,
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.d_init = fuse_dentry_init,
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.d_release = fuse_dentry_release,
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};
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const struct dentry_operations fuse_root_dentry_operations = {
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.d_init = fuse_dentry_init,
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.d_release = fuse_dentry_release,
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};
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int fuse_valid_type(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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int fuse_lookup_name(struct super_block *sb, u64 nodeid, const struct qstr *name,
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struct fuse_entry_out *outarg, struct inode **inode)
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{
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struct fuse_conn *fc = get_fuse_conn_super(sb);
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FUSE_ARGS(args);
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struct fuse_forget_link *forget;
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u64 attr_version;
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int err;
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*inode = NULL;
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err = -ENAMETOOLONG;
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if (name->len > FUSE_NAME_MAX)
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goto out;
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forget = fuse_alloc_forget();
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err = -ENOMEM;
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if (!forget)
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goto out;
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attr_version = fuse_get_attr_version(fc);
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fuse_lookup_init(fc, &args, nodeid, name, outarg);
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err = fuse_simple_request(fc, &args);
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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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goto out_put_forget;
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err = -EIO;
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if (!outarg->nodeid)
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goto out_put_forget;
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if (!fuse_valid_type(outarg->attr.mode))
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goto out_put_forget;
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*inode = fuse_iget(sb, outarg->nodeid, outarg->generation,
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&outarg->attr, entry_attr_timeout(outarg),
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attr_version);
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err = -ENOMEM;
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if (!*inode) {
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fuse_queue_forget(fc, forget, outarg->nodeid, 1);
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goto out;
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}
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err = 0;
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out_put_forget:
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kfree(forget);
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out:
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return err;
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}
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static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry,
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unsigned int flags)
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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;
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struct dentry *newent;
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bool outarg_valid = true;
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fuse_lock_inode(dir);
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err = fuse_lookup_name(dir->i_sb, get_node_id(dir), &entry->d_name,
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&outarg, &inode);
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fuse_unlock_inode(dir);
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if (err == -ENOENT) {
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outarg_valid = false;
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err = 0;
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}
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if (err)
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goto out_err;
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err = -EIO;
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if (inode && get_node_id(inode) == FUSE_ROOT_ID)
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goto out_iput;
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newent = d_splice_alias(inode, entry);
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err = PTR_ERR(newent);
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if (IS_ERR(newent))
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goto out_err;
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entry = newent ? newent : entry;
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if (outarg_valid)
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fuse_change_entry_timeout(entry, &outarg);
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else
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fuse_invalidate_entry_cache(entry);
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|
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fuse_advise_use_readdirplus(dir);
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return newent;
|
|
|
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out_iput:
|
|
iput(inode);
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out_err:
|
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return ERR_PTR(err);
|
|
}
|
|
|
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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,
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struct file *file, unsigned flags,
|
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umode_t mode, int *opened)
|
|
{
|
|
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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FUSE_ARGS(args);
|
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struct fuse_forget_link *forget;
|
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struct fuse_create_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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/* Userspace expects S_IFREG in create mode */
|
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BUG_ON((mode & S_IFMT) != S_IFREG);
|
|
|
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forget = fuse_alloc_forget();
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err = -ENOMEM;
|
|
if (!forget)
|
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goto out_err;
|
|
|
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err = -ENOMEM;
|
|
ff = fuse_file_alloc(fc);
|
|
if (!ff)
|
|
goto out_put_forget_req;
|
|
|
|
if (!fc->dont_mask)
|
|
mode &= ~current_umask();
|
|
|
|
flags &= ~O_NOCTTY;
|
|
memset(&inarg, 0, sizeof(inarg));
|
|
memset(&outentry, 0, sizeof(outentry));
|
|
inarg.flags = flags;
|
|
inarg.mode = mode;
|
|
inarg.umask = current_umask();
|
|
args.in.h.opcode = FUSE_CREATE;
|
|
args.in.h.nodeid = get_node_id(dir);
|
|
args.in.numargs = 2;
|
|
args.in.args[0].size = sizeof(inarg);
|
|
args.in.args[0].value = &inarg;
|
|
args.in.args[1].size = entry->d_name.len + 1;
|
|
args.in.args[1].value = entry->d_name.name;
|
|
args.out.numargs = 2;
|
|
args.out.args[0].size = sizeof(outentry);
|
|
args.out.args[0].value = &outentry;
|
|
args.out.args[1].size = sizeof(outopen);
|
|
args.out.args[1].value = &outopen;
|
|
err = fuse_simple_request(fc, &args);
|
|
if (err)
|
|
goto out_free_ff;
|
|
|
|
err = -EIO;
|
|
if (!S_ISREG(outentry.attr.mode) || invalid_nodeid(outentry.nodeid))
|
|
goto out_free_ff;
|
|
|
|
ff->fh = outopen.fh;
|
|
ff->nodeid = outentry.nodeid;
|
|
ff->open_flags = outopen.open_flags;
|
|
inode = fuse_iget(dir->i_sb, outentry.nodeid, outentry.generation,
|
|
&outentry.attr, entry_attr_timeout(&outentry), 0);
|
|
if (!inode) {
|
|
flags &= ~(O_CREAT | O_EXCL | O_TRUNC);
|
|
fuse_sync_release(ff, flags);
|
|
fuse_queue_forget(fc, forget, outentry.nodeid, 1);
|
|
err = -ENOMEM;
|
|
goto out_err;
|
|
}
|
|
kfree(forget);
|
|
d_instantiate(entry, inode);
|
|
fuse_change_entry_timeout(entry, &outentry);
|
|
fuse_invalidate_attr(dir);
|
|
err = finish_open(file, entry, generic_file_open, opened);
|
|
if (err) {
|
|
fuse_sync_release(ff, flags);
|
|
} else {
|
|
file->private_data = ff;
|
|
fuse_finish_open(inode, file);
|
|
}
|
|
return err;
|
|
|
|
out_free_ff:
|
|
fuse_file_free(ff);
|
|
out_put_forget_req:
|
|
kfree(forget);
|
|
out_err:
|
|
return err;
|
|
}
|
|
|
|
static int fuse_mknod(struct inode *, struct dentry *, umode_t, dev_t);
|
|
static int fuse_atomic_open(struct inode *dir, struct dentry *entry,
|
|
struct file *file, unsigned flags,
|
|
umode_t mode, int *opened)
|
|
{
|
|
int err;
|
|
struct fuse_conn *fc = get_fuse_conn(dir);
|
|
struct dentry *res = NULL;
|
|
|
|
if (d_in_lookup(entry)) {
|
|
res = fuse_lookup(dir, entry, 0);
|
|
if (IS_ERR(res))
|
|
return PTR_ERR(res);
|
|
|
|
if (res)
|
|
entry = res;
|
|
}
|
|
|
|
if (!(flags & O_CREAT) || d_really_is_positive(entry))
|
|
goto no_open;
|
|
|
|
/* Only creates */
|
|
*opened |= FILE_CREATED;
|
|
|
|
if (fc->no_create)
|
|
goto mknod;
|
|
|
|
err = fuse_create_open(dir, entry, file, flags, mode, opened);
|
|
if (err == -ENOSYS) {
|
|
fc->no_create = 1;
|
|
goto mknod;
|
|
}
|
|
out_dput:
|
|
dput(res);
|
|
return err;
|
|
|
|
mknod:
|
|
err = fuse_mknod(dir, entry, mode, 0);
|
|
if (err)
|
|
goto out_dput;
|
|
no_open:
|
|
return finish_no_open(file, res);
|
|
}
|
|
|
|
/*
|
|
* Code shared between mknod, mkdir, symlink and link
|
|
*/
|
|
static int create_new_entry(struct fuse_conn *fc, struct fuse_args *args,
|
|
struct inode *dir, struct dentry *entry,
|
|
umode_t mode)
|
|
{
|
|
struct fuse_entry_out outarg;
|
|
struct inode *inode;
|
|
int err;
|
|
struct fuse_forget_link *forget;
|
|
|
|
forget = fuse_alloc_forget();
|
|
if (!forget)
|
|
return -ENOMEM;
|
|
|
|
memset(&outarg, 0, sizeof(outarg));
|
|
args->in.h.nodeid = get_node_id(dir);
|
|
args->out.numargs = 1;
|
|
args->out.args[0].size = sizeof(outarg);
|
|
args->out.args[0].value = &outarg;
|
|
err = fuse_simple_request(fc, args);
|
|
if (err)
|
|
goto out_put_forget_req;
|
|
|
|
err = -EIO;
|
|
if (invalid_nodeid(outarg.nodeid))
|
|
goto out_put_forget_req;
|
|
|
|
if ((outarg.attr.mode ^ mode) & S_IFMT)
|
|
goto out_put_forget_req;
|
|
|
|
inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation,
|
|
&outarg.attr, entry_attr_timeout(&outarg), 0);
|
|
if (!inode) {
|
|
fuse_queue_forget(fc, forget, outarg.nodeid, 1);
|
|
return -ENOMEM;
|
|
}
|
|
kfree(forget);
|
|
|
|
err = d_instantiate_no_diralias(entry, inode);
|
|
if (err)
|
|
return err;
|
|
|
|
fuse_change_entry_timeout(entry, &outarg);
|
|
fuse_invalidate_attr(dir);
|
|
return 0;
|
|
|
|
out_put_forget_req:
|
|
kfree(forget);
|
|
return err;
|
|
}
|
|
|
|
static int fuse_mknod(struct inode *dir, struct dentry *entry, umode_t mode,
|
|
dev_t rdev)
|
|
{
|
|
struct fuse_mknod_in inarg;
|
|
struct fuse_conn *fc = get_fuse_conn(dir);
|
|
FUSE_ARGS(args);
|
|
|
|
if (!fc->dont_mask)
|
|
mode &= ~current_umask();
|
|
|
|
memset(&inarg, 0, sizeof(inarg));
|
|
inarg.mode = mode;
|
|
inarg.rdev = new_encode_dev(rdev);
|
|
inarg.umask = current_umask();
|
|
args.in.h.opcode = FUSE_MKNOD;
|
|
args.in.numargs = 2;
|
|
args.in.args[0].size = sizeof(inarg);
|
|
args.in.args[0].value = &inarg;
|
|
args.in.args[1].size = entry->d_name.len + 1;
|
|
args.in.args[1].value = entry->d_name.name;
|
|
return create_new_entry(fc, &args, dir, entry, mode);
|
|
}
|
|
|
|
static int fuse_create(struct inode *dir, struct dentry *entry, umode_t mode,
|
|
bool excl)
|
|
{
|
|
return fuse_mknod(dir, entry, mode, 0);
|
|
}
|
|
|
|
static int fuse_mkdir(struct inode *dir, struct dentry *entry, umode_t mode)
|
|
{
|
|
struct fuse_mkdir_in inarg;
|
|
struct fuse_conn *fc = get_fuse_conn(dir);
|
|
FUSE_ARGS(args);
|
|
|
|
if (!fc->dont_mask)
|
|
mode &= ~current_umask();
|
|
|
|
memset(&inarg, 0, sizeof(inarg));
|
|
inarg.mode = mode;
|
|
inarg.umask = current_umask();
|
|
args.in.h.opcode = FUSE_MKDIR;
|
|
args.in.numargs = 2;
|
|
args.in.args[0].size = sizeof(inarg);
|
|
args.in.args[0].value = &inarg;
|
|
args.in.args[1].size = entry->d_name.len + 1;
|
|
args.in.args[1].value = entry->d_name.name;
|
|
return create_new_entry(fc, &args, dir, entry, S_IFDIR);
|
|
}
|
|
|
|
static int fuse_symlink(struct inode *dir, struct dentry *entry,
|
|
const char *link)
|
|
{
|
|
struct fuse_conn *fc = get_fuse_conn(dir);
|
|
unsigned len = strlen(link) + 1;
|
|
FUSE_ARGS(args);
|
|
|
|
args.in.h.opcode = FUSE_SYMLINK;
|
|
args.in.numargs = 2;
|
|
args.in.args[0].size = entry->d_name.len + 1;
|
|
args.in.args[0].value = entry->d_name.name;
|
|
args.in.args[1].size = len;
|
|
args.in.args[1].value = link;
|
|
return create_new_entry(fc, &args, dir, entry, S_IFLNK);
|
|
}
|
|
|
|
void fuse_update_ctime(struct inode *inode)
|
|
{
|
|
if (!IS_NOCMTIME(inode)) {
|
|
inode->i_ctime = current_time(inode);
|
|
mark_inode_dirty_sync(inode);
|
|
}
|
|
}
|
|
|
|
static int fuse_unlink(struct inode *dir, struct dentry *entry)
|
|
{
|
|
int err;
|
|
struct fuse_conn *fc = get_fuse_conn(dir);
|
|
FUSE_ARGS(args);
|
|
|
|
args.in.h.opcode = FUSE_UNLINK;
|
|
args.in.h.nodeid = get_node_id(dir);
|
|
args.in.numargs = 1;
|
|
args.in.args[0].size = entry->d_name.len + 1;
|
|
args.in.args[0].value = entry->d_name.name;
|
|
err = fuse_simple_request(fc, &args);
|
|
if (!err) {
|
|
struct inode *inode = d_inode(entry);
|
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
|
|
|
spin_lock(&fc->lock);
|
|
fi->attr_version = ++fc->attr_version;
|
|
/*
|
|
* If i_nlink == 0 then unlink doesn't make sense, yet this can
|
|
* happen if userspace filesystem is careless. It would be
|
|
* difficult to enforce correct nlink usage so just ignore this
|
|
* condition here
|
|
*/
|
|
if (inode->i_nlink > 0)
|
|
drop_nlink(inode);
|
|
spin_unlock(&fc->lock);
|
|
fuse_invalidate_attr(inode);
|
|
fuse_invalidate_attr(dir);
|
|
fuse_invalidate_entry_cache(entry);
|
|
fuse_update_ctime(inode);
|
|
} else if (err == -EINTR)
|
|
fuse_invalidate_entry(entry);
|
|
return err;
|
|
}
|
|
|
|
static int fuse_rmdir(struct inode *dir, struct dentry *entry)
|
|
{
|
|
int err;
|
|
struct fuse_conn *fc = get_fuse_conn(dir);
|
|
FUSE_ARGS(args);
|
|
|
|
args.in.h.opcode = FUSE_RMDIR;
|
|
args.in.h.nodeid = get_node_id(dir);
|
|
args.in.numargs = 1;
|
|
args.in.args[0].size = entry->d_name.len + 1;
|
|
args.in.args[0].value = entry->d_name.name;
|
|
err = fuse_simple_request(fc, &args);
|
|
if (!err) {
|
|
clear_nlink(d_inode(entry));
|
|
fuse_invalidate_attr(dir);
|
|
fuse_invalidate_entry_cache(entry);
|
|
} else if (err == -EINTR)
|
|
fuse_invalidate_entry(entry);
|
|
return err;
|
|
}
|
|
|
|
static int fuse_rename_common(struct inode *olddir, struct dentry *oldent,
|
|
struct inode *newdir, struct dentry *newent,
|
|
unsigned int flags, int opcode, size_t argsize)
|
|
{
|
|
int err;
|
|
struct fuse_rename2_in inarg;
|
|
struct fuse_conn *fc = get_fuse_conn(olddir);
|
|
FUSE_ARGS(args);
|
|
|
|
memset(&inarg, 0, argsize);
|
|
inarg.newdir = get_node_id(newdir);
|
|
inarg.flags = flags;
|
|
args.in.h.opcode = opcode;
|
|
args.in.h.nodeid = get_node_id(olddir);
|
|
args.in.numargs = 3;
|
|
args.in.args[0].size = argsize;
|
|
args.in.args[0].value = &inarg;
|
|
args.in.args[1].size = oldent->d_name.len + 1;
|
|
args.in.args[1].value = oldent->d_name.name;
|
|
args.in.args[2].size = newent->d_name.len + 1;
|
|
args.in.args[2].value = newent->d_name.name;
|
|
err = fuse_simple_request(fc, &args);
|
|
if (!err) {
|
|
/* ctime changes */
|
|
fuse_invalidate_attr(d_inode(oldent));
|
|
fuse_update_ctime(d_inode(oldent));
|
|
|
|
if (flags & RENAME_EXCHANGE) {
|
|
fuse_invalidate_attr(d_inode(newent));
|
|
fuse_update_ctime(d_inode(newent));
|
|
}
|
|
|
|
fuse_invalidate_attr(olddir);
|
|
if (olddir != newdir)
|
|
fuse_invalidate_attr(newdir);
|
|
|
|
/* newent will end up negative */
|
|
if (!(flags & RENAME_EXCHANGE) && d_really_is_positive(newent)) {
|
|
fuse_invalidate_attr(d_inode(newent));
|
|
fuse_invalidate_entry_cache(newent);
|
|
fuse_update_ctime(d_inode(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 (d_really_is_positive(newent))
|
|
fuse_invalidate_entry(newent);
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
static int fuse_rename2(struct inode *olddir, struct dentry *oldent,
|
|
struct inode *newdir, struct dentry *newent,
|
|
unsigned int flags)
|
|
{
|
|
struct fuse_conn *fc = get_fuse_conn(olddir);
|
|
int err;
|
|
|
|
if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE))
|
|
return -EINVAL;
|
|
|
|
if (flags) {
|
|
if (fc->no_rename2 || fc->minor < 23)
|
|
return -EINVAL;
|
|
|
|
err = fuse_rename_common(olddir, oldent, newdir, newent, flags,
|
|
FUSE_RENAME2,
|
|
sizeof(struct fuse_rename2_in));
|
|
if (err == -ENOSYS) {
|
|
fc->no_rename2 = 1;
|
|
err = -EINVAL;
|
|
}
|
|
} else {
|
|
err = fuse_rename_common(olddir, oldent, newdir, newent, 0,
|
|
FUSE_RENAME,
|
|
sizeof(struct fuse_rename_in));
|
|
}
|
|
|
|
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 = d_inode(entry);
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
FUSE_ARGS(args);
|
|
|
|
memset(&inarg, 0, sizeof(inarg));
|
|
inarg.oldnodeid = get_node_id(inode);
|
|
args.in.h.opcode = FUSE_LINK;
|
|
args.in.numargs = 2;
|
|
args.in.args[0].size = sizeof(inarg);
|
|
args.in.args[0].value = &inarg;
|
|
args.in.args[1].size = newent->d_name.len + 1;
|
|
args.in.args[1].value = newent->d_name.name;
|
|
err = create_new_entry(fc, &args, 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) {
|
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
|
|
|
spin_lock(&fc->lock);
|
|
fi->attr_version = ++fc->attr_version;
|
|
inc_nlink(inode);
|
|
spin_unlock(&fc->lock);
|
|
fuse_invalidate_attr(inode);
|
|
fuse_update_ctime(inode);
|
|
} else if (err == -EINTR) {
|
|
fuse_invalidate_attr(inode);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static void fuse_fillattr(struct inode *inode, struct fuse_attr *attr,
|
|
struct kstat *stat)
|
|
{
|
|
unsigned int blkbits;
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
|
|
/* see the comment in fuse_change_attributes() */
|
|
if (fc->writeback_cache && S_ISREG(inode->i_mode)) {
|
|
attr->size = i_size_read(inode);
|
|
attr->mtime = inode->i_mtime.tv_sec;
|
|
attr->mtimensec = inode->i_mtime.tv_nsec;
|
|
attr->ctime = inode->i_ctime.tv_sec;
|
|
attr->ctimensec = inode->i_ctime.tv_nsec;
|
|
}
|
|
|
|
stat->dev = inode->i_sb->s_dev;
|
|
stat->ino = attr->ino;
|
|
stat->mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
|
|
stat->nlink = attr->nlink;
|
|
stat->uid = make_kuid(&init_user_ns, attr->uid);
|
|
stat->gid = make_kgid(&init_user_ns, attr->gid);
|
|
stat->rdev = inode->i_rdev;
|
|
stat->atime.tv_sec = attr->atime;
|
|
stat->atime.tv_nsec = attr->atimensec;
|
|
stat->mtime.tv_sec = attr->mtime;
|
|
stat->mtime.tv_nsec = attr->mtimensec;
|
|
stat->ctime.tv_sec = attr->ctime;
|
|
stat->ctime.tv_nsec = attr->ctimensec;
|
|
stat->size = attr->size;
|
|
stat->blocks = attr->blocks;
|
|
|
|
if (attr->blksize != 0)
|
|
blkbits = ilog2(attr->blksize);
|
|
else
|
|
blkbits = inode->i_sb->s_blocksize_bits;
|
|
|
|
stat->blksize = 1 << blkbits;
|
|
}
|
|
|
|
static int fuse_do_getattr(struct inode *inode, struct kstat *stat,
|
|
struct file *file)
|
|
{
|
|
int err;
|
|
struct fuse_getattr_in inarg;
|
|
struct fuse_attr_out outarg;
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
FUSE_ARGS(args);
|
|
u64 attr_version;
|
|
|
|
attr_version = fuse_get_attr_version(fc);
|
|
|
|
memset(&inarg, 0, sizeof(inarg));
|
|
memset(&outarg, 0, sizeof(outarg));
|
|
/* Directories have separate file-handle space */
|
|
if (file && S_ISREG(inode->i_mode)) {
|
|
struct fuse_file *ff = file->private_data;
|
|
|
|
inarg.getattr_flags |= FUSE_GETATTR_FH;
|
|
inarg.fh = ff->fh;
|
|
}
|
|
args.in.h.opcode = FUSE_GETATTR;
|
|
args.in.h.nodeid = get_node_id(inode);
|
|
args.in.numargs = 1;
|
|
args.in.args[0].size = sizeof(inarg);
|
|
args.in.args[0].value = &inarg;
|
|
args.out.numargs = 1;
|
|
args.out.args[0].size = sizeof(outarg);
|
|
args.out.args[0].value = &outarg;
|
|
err = fuse_simple_request(fc, &args);
|
|
if (!err) {
|
|
if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) {
|
|
make_bad_inode(inode);
|
|
err = -EIO;
|
|
} else {
|
|
fuse_change_attributes(inode, &outarg.attr,
|
|
attr_timeout(&outarg),
|
|
attr_version);
|
|
if (stat)
|
|
fuse_fillattr(inode, &outarg.attr, stat);
|
|
}
|
|
}
|
|
return err;
|
|
}
|
|
|
|
int fuse_update_attributes(struct inode *inode, struct kstat *stat,
|
|
struct file *file, bool *refreshed)
|
|
{
|
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
|
int err;
|
|
bool r;
|
|
|
|
if (time_before64(fi->i_time, get_jiffies_64())) {
|
|
r = true;
|
|
forget_all_cached_acls(inode);
|
|
err = fuse_do_getattr(inode, stat, file);
|
|
} else {
|
|
r = false;
|
|
err = 0;
|
|
if (stat) {
|
|
generic_fillattr(inode, stat);
|
|
stat->mode = fi->orig_i_mode;
|
|
stat->ino = fi->orig_ino;
|
|
}
|
|
}
|
|
|
|
if (refreshed != NULL)
|
|
*refreshed = r;
|
|
|
|
return err;
|
|
}
|
|
|
|
int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
|
|
u64 child_nodeid, struct qstr *name)
|
|
{
|
|
int err = -ENOTDIR;
|
|
struct inode *parent;
|
|
struct dentry *dir;
|
|
struct dentry *entry;
|
|
|
|
parent = ilookup5(sb, parent_nodeid, fuse_inode_eq, &parent_nodeid);
|
|
if (!parent)
|
|
return -ENOENT;
|
|
|
|
inode_lock(parent);
|
|
if (!S_ISDIR(parent->i_mode))
|
|
goto unlock;
|
|
|
|
err = -ENOENT;
|
|
dir = d_find_alias(parent);
|
|
if (!dir)
|
|
goto unlock;
|
|
|
|
name->hash = full_name_hash(dir, name->name, name->len);
|
|
entry = d_lookup(dir, name);
|
|
dput(dir);
|
|
if (!entry)
|
|
goto unlock;
|
|
|
|
fuse_invalidate_attr(parent);
|
|
fuse_invalidate_entry(entry);
|
|
|
|
if (child_nodeid != 0 && d_really_is_positive(entry)) {
|
|
inode_lock(d_inode(entry));
|
|
if (get_node_id(d_inode(entry)) != child_nodeid) {
|
|
err = -ENOENT;
|
|
goto badentry;
|
|
}
|
|
if (d_mountpoint(entry)) {
|
|
err = -EBUSY;
|
|
goto badentry;
|
|
}
|
|
if (d_is_dir(entry)) {
|
|
shrink_dcache_parent(entry);
|
|
if (!simple_empty(entry)) {
|
|
err = -ENOTEMPTY;
|
|
goto badentry;
|
|
}
|
|
d_inode(entry)->i_flags |= S_DEAD;
|
|
}
|
|
dont_mount(entry);
|
|
clear_nlink(d_inode(entry));
|
|
err = 0;
|
|
badentry:
|
|
inode_unlock(d_inode(entry));
|
|
if (!err)
|
|
d_delete(entry);
|
|
} else {
|
|
err = 0;
|
|
}
|
|
dput(entry);
|
|
|
|
unlock:
|
|
inode_unlock(parent);
|
|
iput(parent);
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Calling into a user-controlled filesystem gives the filesystem
|
|
* daemon ptrace-like capabilities over the current 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.
|
|
*/
|
|
int fuse_allow_current_process(struct fuse_conn *fc)
|
|
{
|
|
const struct cred *cred;
|
|
|
|
if (fc->allow_other)
|
|
return 1;
|
|
|
|
cred = current_cred();
|
|
if (uid_eq(cred->euid, fc->user_id) &&
|
|
uid_eq(cred->suid, fc->user_id) &&
|
|
uid_eq(cred->uid, fc->user_id) &&
|
|
gid_eq(cred->egid, fc->group_id) &&
|
|
gid_eq(cred->sgid, fc->group_id) &&
|
|
gid_eq(cred->gid, fc->group_id))
|
|
return 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int fuse_access(struct inode *inode, int mask)
|
|
{
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
FUSE_ARGS(args);
|
|
struct fuse_access_in inarg;
|
|
int err;
|
|
|
|
BUG_ON(mask & MAY_NOT_BLOCK);
|
|
|
|
if (fc->no_access)
|
|
return 0;
|
|
|
|
memset(&inarg, 0, sizeof(inarg));
|
|
inarg.mask = mask & (MAY_READ | MAY_WRITE | MAY_EXEC);
|
|
args.in.h.opcode = FUSE_ACCESS;
|
|
args.in.h.nodeid = get_node_id(inode);
|
|
args.in.numargs = 1;
|
|
args.in.args[0].size = sizeof(inarg);
|
|
args.in.args[0].value = &inarg;
|
|
err = fuse_simple_request(fc, &args);
|
|
if (err == -ENOSYS) {
|
|
fc->no_access = 1;
|
|
err = 0;
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static int fuse_perm_getattr(struct inode *inode, int mask)
|
|
{
|
|
if (mask & MAY_NOT_BLOCK)
|
|
return -ECHILD;
|
|
|
|
forget_all_cached_acls(inode);
|
|
return fuse_do_getattr(inode, NULL, NULL);
|
|
}
|
|
|
|
/*
|
|
* 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 fuse_conn *fc = get_fuse_conn(inode);
|
|
bool refreshed = false;
|
|
int err = 0;
|
|
|
|
if (!fuse_allow_current_process(fc))
|
|
return -EACCES;
|
|
|
|
/*
|
|
* If attributes are needed, refresh them before proceeding
|
|
*/
|
|
if (fc->default_permissions ||
|
|
((mask & MAY_EXEC) && S_ISREG(inode->i_mode))) {
|
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
|
|
|
if (time_before64(fi->i_time, get_jiffies_64())) {
|
|
refreshed = true;
|
|
|
|
err = fuse_perm_getattr(inode, mask);
|
|
if (err)
|
|
return err;
|
|
}
|
|
}
|
|
|
|
if (fc->default_permissions) {
|
|
err = generic_permission(inode, mask);
|
|
|
|
/* 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 && !refreshed) {
|
|
err = fuse_perm_getattr(inode, mask);
|
|
if (!err)
|
|
err = generic_permission(inode, mask);
|
|
}
|
|
|
|
/* 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 */
|
|
} else if (mask & (MAY_ACCESS | MAY_CHDIR)) {
|
|
err = fuse_access(inode, mask);
|
|
} else if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) {
|
|
if (!(inode->i_mode & S_IXUGO)) {
|
|
if (refreshed)
|
|
return -EACCES;
|
|
|
|
err = fuse_perm_getattr(inode, mask);
|
|
if (!err && !(inode->i_mode & S_IXUGO))
|
|
return -EACCES;
|
|
}
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static int parse_dirfile(char *buf, size_t nbytes, struct file *file,
|
|
struct dir_context *ctx)
|
|
{
|
|
while (nbytes >= FUSE_NAME_OFFSET) {
|
|
struct fuse_dirent *dirent = (struct fuse_dirent *) buf;
|
|
size_t reclen = FUSE_DIRENT_SIZE(dirent);
|
|
if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX)
|
|
return -EIO;
|
|
if (reclen > nbytes)
|
|
break;
|
|
if (memchr(dirent->name, '/', dirent->namelen) != NULL)
|
|
return -EIO;
|
|
|
|
if (!dir_emit(ctx, dirent->name, dirent->namelen,
|
|
dirent->ino, dirent->type))
|
|
break;
|
|
|
|
buf += reclen;
|
|
nbytes -= reclen;
|
|
ctx->pos = dirent->off;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int fuse_direntplus_link(struct file *file,
|
|
struct fuse_direntplus *direntplus,
|
|
u64 attr_version)
|
|
{
|
|
struct fuse_entry_out *o = &direntplus->entry_out;
|
|
struct fuse_dirent *dirent = &direntplus->dirent;
|
|
struct dentry *parent = file->f_path.dentry;
|
|
struct qstr name = QSTR_INIT(dirent->name, dirent->namelen);
|
|
struct dentry *dentry;
|
|
struct dentry *alias;
|
|
struct inode *dir = d_inode(parent);
|
|
struct fuse_conn *fc;
|
|
struct inode *inode;
|
|
DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
|
|
|
|
if (!o->nodeid) {
|
|
/*
|
|
* Unlike in the case of fuse_lookup, zero nodeid does not mean
|
|
* ENOENT. Instead, it only means the userspace filesystem did
|
|
* not want to return attributes/handle for this entry.
|
|
*
|
|
* So do nothing.
|
|
*/
|
|
return 0;
|
|
}
|
|
|
|
if (name.name[0] == '.') {
|
|
/*
|
|
* We could potentially refresh the attributes of the directory
|
|
* and its parent?
|
|
*/
|
|
if (name.len == 1)
|
|
return 0;
|
|
if (name.name[1] == '.' && name.len == 2)
|
|
return 0;
|
|
}
|
|
|
|
if (invalid_nodeid(o->nodeid))
|
|
return -EIO;
|
|
if (!fuse_valid_type(o->attr.mode))
|
|
return -EIO;
|
|
|
|
fc = get_fuse_conn(dir);
|
|
|
|
name.hash = full_name_hash(parent, name.name, name.len);
|
|
dentry = d_lookup(parent, &name);
|
|
if (!dentry) {
|
|
retry:
|
|
dentry = d_alloc_parallel(parent, &name, &wq);
|
|
if (IS_ERR(dentry))
|
|
return PTR_ERR(dentry);
|
|
}
|
|
if (!d_in_lookup(dentry)) {
|
|
struct fuse_inode *fi;
|
|
inode = d_inode(dentry);
|
|
if (!inode ||
|
|
get_node_id(inode) != o->nodeid ||
|
|
((o->attr.mode ^ inode->i_mode) & S_IFMT)) {
|
|
d_invalidate(dentry);
|
|
dput(dentry);
|
|
goto retry;
|
|
}
|
|
if (is_bad_inode(inode)) {
|
|
dput(dentry);
|
|
return -EIO;
|
|
}
|
|
|
|
fi = get_fuse_inode(inode);
|
|
spin_lock(&fc->lock);
|
|
fi->nlookup++;
|
|
spin_unlock(&fc->lock);
|
|
|
|
forget_all_cached_acls(inode);
|
|
fuse_change_attributes(inode, &o->attr,
|
|
entry_attr_timeout(o),
|
|
attr_version);
|
|
/*
|
|
* The other branch comes via fuse_iget()
|
|
* which bumps nlookup inside
|
|
*/
|
|
} else {
|
|
inode = fuse_iget(dir->i_sb, o->nodeid, o->generation,
|
|
&o->attr, entry_attr_timeout(o),
|
|
attr_version);
|
|
if (!inode)
|
|
inode = ERR_PTR(-ENOMEM);
|
|
|
|
alias = d_splice_alias(inode, dentry);
|
|
d_lookup_done(dentry);
|
|
if (alias) {
|
|
dput(dentry);
|
|
dentry = alias;
|
|
}
|
|
if (IS_ERR(dentry))
|
|
return PTR_ERR(dentry);
|
|
}
|
|
if (fc->readdirplus_auto)
|
|
set_bit(FUSE_I_INIT_RDPLUS, &get_fuse_inode(inode)->state);
|
|
fuse_change_entry_timeout(dentry, o);
|
|
|
|
dput(dentry);
|
|
return 0;
|
|
}
|
|
|
|
static int parse_dirplusfile(char *buf, size_t nbytes, struct file *file,
|
|
struct dir_context *ctx, u64 attr_version)
|
|
{
|
|
struct fuse_direntplus *direntplus;
|
|
struct fuse_dirent *dirent;
|
|
size_t reclen;
|
|
int over = 0;
|
|
int ret;
|
|
|
|
while (nbytes >= FUSE_NAME_OFFSET_DIRENTPLUS) {
|
|
direntplus = (struct fuse_direntplus *) buf;
|
|
dirent = &direntplus->dirent;
|
|
reclen = FUSE_DIRENTPLUS_SIZE(direntplus);
|
|
|
|
if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX)
|
|
return -EIO;
|
|
if (reclen > nbytes)
|
|
break;
|
|
if (memchr(dirent->name, '/', dirent->namelen) != NULL)
|
|
return -EIO;
|
|
|
|
if (!over) {
|
|
/* We fill entries into dstbuf only as much as
|
|
it can hold. But we still continue iterating
|
|
over remaining entries to link them. If not,
|
|
we need to send a FORGET for each of those
|
|
which we did not link.
|
|
*/
|
|
over = !dir_emit(ctx, dirent->name, dirent->namelen,
|
|
dirent->ino, dirent->type);
|
|
ctx->pos = dirent->off;
|
|
}
|
|
|
|
buf += reclen;
|
|
nbytes -= reclen;
|
|
|
|
ret = fuse_direntplus_link(file, direntplus, attr_version);
|
|
if (ret)
|
|
fuse_force_forget(file, direntplus->entry_out.nodeid);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int fuse_readdir(struct file *file, struct dir_context *ctx)
|
|
{
|
|
int plus, err;
|
|
size_t nbytes;
|
|
struct page *page;
|
|
struct inode *inode = file_inode(file);
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_req *req;
|
|
u64 attr_version = 0;
|
|
|
|
if (is_bad_inode(inode))
|
|
return -EIO;
|
|
|
|
req = fuse_get_req(fc, 1);
|
|
if (IS_ERR(req))
|
|
return PTR_ERR(req);
|
|
|
|
page = alloc_page(GFP_KERNEL);
|
|
if (!page) {
|
|
fuse_put_request(fc, req);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
plus = fuse_use_readdirplus(inode, ctx);
|
|
req->out.argpages = 1;
|
|
req->num_pages = 1;
|
|
req->pages[0] = page;
|
|
req->page_descs[0].length = PAGE_SIZE;
|
|
if (plus) {
|
|
attr_version = fuse_get_attr_version(fc);
|
|
fuse_read_fill(req, file, ctx->pos, PAGE_SIZE,
|
|
FUSE_READDIRPLUS);
|
|
} else {
|
|
fuse_read_fill(req, file, ctx->pos, PAGE_SIZE,
|
|
FUSE_READDIR);
|
|
}
|
|
fuse_lock_inode(inode);
|
|
fuse_request_send(fc, req);
|
|
fuse_unlock_inode(inode);
|
|
nbytes = req->out.args[0].size;
|
|
err = req->out.h.error;
|
|
fuse_put_request(fc, req);
|
|
if (!err) {
|
|
if (plus) {
|
|
err = parse_dirplusfile(page_address(page), nbytes,
|
|
file, ctx,
|
|
attr_version);
|
|
} else {
|
|
err = parse_dirfile(page_address(page), nbytes, file,
|
|
ctx);
|
|
}
|
|
}
|
|
|
|
__free_page(page);
|
|
fuse_invalidate_atime(inode);
|
|
return err;
|
|
}
|
|
|
|
static const char *fuse_get_link(struct dentry *dentry,
|
|
struct inode *inode,
|
|
struct delayed_call *done)
|
|
{
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
FUSE_ARGS(args);
|
|
char *link;
|
|
ssize_t ret;
|
|
|
|
if (!dentry)
|
|
return ERR_PTR(-ECHILD);
|
|
|
|
link = kmalloc(PAGE_SIZE, GFP_KERNEL);
|
|
if (!link)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
args.in.h.opcode = FUSE_READLINK;
|
|
args.in.h.nodeid = get_node_id(inode);
|
|
args.out.argvar = 1;
|
|
args.out.numargs = 1;
|
|
args.out.args[0].size = PAGE_SIZE - 1;
|
|
args.out.args[0].value = link;
|
|
ret = fuse_simple_request(fc, &args);
|
|
if (ret < 0) {
|
|
kfree(link);
|
|
link = ERR_PTR(ret);
|
|
} else {
|
|
link[ret] = '\0';
|
|
set_delayed_call(done, kfree_link, link);
|
|
}
|
|
fuse_invalidate_atime(inode);
|
|
return link;
|
|
}
|
|
|
|
static int fuse_dir_open(struct inode *inode, struct file *file)
|
|
{
|
|
return fuse_open_common(inode, file, true);
|
|
}
|
|
|
|
static int fuse_dir_release(struct inode *inode, struct file *file)
|
|
{
|
|
fuse_release_common(file, FUSE_RELEASEDIR);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int fuse_dir_fsync(struct file *file, loff_t start, loff_t end,
|
|
int datasync)
|
|
{
|
|
return fuse_fsync_common(file, start, end, datasync, 1);
|
|
}
|
|
|
|
static long fuse_dir_ioctl(struct file *file, unsigned int cmd,
|
|
unsigned long arg)
|
|
{
|
|
struct fuse_conn *fc = get_fuse_conn(file->f_mapping->host);
|
|
|
|
/* FUSE_IOCTL_DIR only supported for API version >= 7.18 */
|
|
if (fc->minor < 18)
|
|
return -ENOTTY;
|
|
|
|
return fuse_ioctl_common(file, cmd, arg, FUSE_IOCTL_DIR);
|
|
}
|
|
|
|
static long fuse_dir_compat_ioctl(struct file *file, unsigned int cmd,
|
|
unsigned long arg)
|
|
{
|
|
struct fuse_conn *fc = get_fuse_conn(file->f_mapping->host);
|
|
|
|
if (fc->minor < 18)
|
|
return -ENOTTY;
|
|
|
|
return fuse_ioctl_common(file, cmd, arg,
|
|
FUSE_IOCTL_COMPAT | FUSE_IOCTL_DIR);
|
|
}
|
|
|
|
static bool update_mtime(unsigned ivalid, bool trust_local_mtime)
|
|
{
|
|
/* Always update if mtime is explicitly set */
|
|
if (ivalid & ATTR_MTIME_SET)
|
|
return true;
|
|
|
|
/* Or if kernel i_mtime is the official one */
|
|
if (trust_local_mtime)
|
|
return true;
|
|
|
|
/* If it's an open(O_TRUNC) or an ftruncate(), don't update */
|
|
if ((ivalid & ATTR_SIZE) && (ivalid & (ATTR_OPEN | ATTR_FILE)))
|
|
return false;
|
|
|
|
/* In all other cases update */
|
|
return true;
|
|
}
|
|
|
|
static void iattr_to_fattr(struct iattr *iattr, struct fuse_setattr_in *arg,
|
|
bool trust_local_cmtime)
|
|
{
|
|
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 = from_kuid(&init_user_ns, iattr->ia_uid);
|
|
if (ivalid & ATTR_GID)
|
|
arg->valid |= FATTR_GID, arg->gid = from_kgid(&init_user_ns, iattr->ia_gid);
|
|
if (ivalid & ATTR_SIZE)
|
|
arg->valid |= FATTR_SIZE, arg->size = iattr->ia_size;
|
|
if (ivalid & ATTR_ATIME) {
|
|
arg->valid |= FATTR_ATIME;
|
|
arg->atime = iattr->ia_atime.tv_sec;
|
|
arg->atimensec = iattr->ia_atime.tv_nsec;
|
|
if (!(ivalid & ATTR_ATIME_SET))
|
|
arg->valid |= FATTR_ATIME_NOW;
|
|
}
|
|
if ((ivalid & ATTR_MTIME) && update_mtime(ivalid, trust_local_cmtime)) {
|
|
arg->valid |= FATTR_MTIME;
|
|
arg->mtime = iattr->ia_mtime.tv_sec;
|
|
arg->mtimensec = iattr->ia_mtime.tv_nsec;
|
|
if (!(ivalid & ATTR_MTIME_SET) && !trust_local_cmtime)
|
|
arg->valid |= FATTR_MTIME_NOW;
|
|
}
|
|
if ((ivalid & ATTR_CTIME) && trust_local_cmtime) {
|
|
arg->valid |= FATTR_CTIME;
|
|
arg->ctime = iattr->ia_ctime.tv_sec;
|
|
arg->ctimensec = iattr->ia_ctime.tv_nsec;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Prevent concurrent writepages on inode
|
|
*
|
|
* This is done by adding a negative bias to the inode write counter
|
|
* and waiting for all pending writes to finish.
|
|
*/
|
|
void fuse_set_nowrite(struct inode *inode)
|
|
{
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
|
|
|
BUG_ON(!inode_is_locked(inode));
|
|
|
|
spin_lock(&fc->lock);
|
|
BUG_ON(fi->writectr < 0);
|
|
fi->writectr += FUSE_NOWRITE;
|
|
spin_unlock(&fc->lock);
|
|
wait_event(fi->page_waitq, fi->writectr == FUSE_NOWRITE);
|
|
}
|
|
|
|
/*
|
|
* Allow writepages on inode
|
|
*
|
|
* Remove the bias from the writecounter and send any queued
|
|
* writepages.
|
|
*/
|
|
static void __fuse_release_nowrite(struct inode *inode)
|
|
{
|
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
|
|
|
BUG_ON(fi->writectr != FUSE_NOWRITE);
|
|
fi->writectr = 0;
|
|
fuse_flush_writepages(inode);
|
|
}
|
|
|
|
void fuse_release_nowrite(struct inode *inode)
|
|
{
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
|
|
spin_lock(&fc->lock);
|
|
__fuse_release_nowrite(inode);
|
|
spin_unlock(&fc->lock);
|
|
}
|
|
|
|
static void fuse_setattr_fill(struct fuse_conn *fc, struct fuse_args *args,
|
|
struct inode *inode,
|
|
struct fuse_setattr_in *inarg_p,
|
|
struct fuse_attr_out *outarg_p)
|
|
{
|
|
args->in.h.opcode = FUSE_SETATTR;
|
|
args->in.h.nodeid = get_node_id(inode);
|
|
args->in.numargs = 1;
|
|
args->in.args[0].size = sizeof(*inarg_p);
|
|
args->in.args[0].value = inarg_p;
|
|
args->out.numargs = 1;
|
|
args->out.args[0].size = sizeof(*outarg_p);
|
|
args->out.args[0].value = outarg_p;
|
|
}
|
|
|
|
/*
|
|
* Flush inode->i_mtime to the server
|
|
*/
|
|
int fuse_flush_times(struct inode *inode, struct fuse_file *ff)
|
|
{
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
FUSE_ARGS(args);
|
|
struct fuse_setattr_in inarg;
|
|
struct fuse_attr_out outarg;
|
|
|
|
memset(&inarg, 0, sizeof(inarg));
|
|
memset(&outarg, 0, sizeof(outarg));
|
|
|
|
inarg.valid = FATTR_MTIME;
|
|
inarg.mtime = inode->i_mtime.tv_sec;
|
|
inarg.mtimensec = inode->i_mtime.tv_nsec;
|
|
if (fc->minor >= 23) {
|
|
inarg.valid |= FATTR_CTIME;
|
|
inarg.ctime = inode->i_ctime.tv_sec;
|
|
inarg.ctimensec = inode->i_ctime.tv_nsec;
|
|
}
|
|
if (ff) {
|
|
inarg.valid |= FATTR_FH;
|
|
inarg.fh = ff->fh;
|
|
}
|
|
fuse_setattr_fill(fc, &args, inode, &inarg, &outarg);
|
|
|
|
return fuse_simple_request(fc, &args);
|
|
}
|
|
|
|
/*
|
|
* 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
|
|
* and the actual truncation by hand.
|
|
*/
|
|
int fuse_do_setattr(struct dentry *dentry, struct iattr *attr,
|
|
struct file *file)
|
|
{
|
|
struct inode *inode = d_inode(dentry);
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_inode *fi = get_fuse_inode(inode);
|
|
FUSE_ARGS(args);
|
|
struct fuse_setattr_in inarg;
|
|
struct fuse_attr_out outarg;
|
|
bool is_truncate = false;
|
|
bool is_wb = fc->writeback_cache;
|
|
loff_t oldsize;
|
|
int err;
|
|
bool trust_local_cmtime = is_wb && S_ISREG(inode->i_mode);
|
|
|
|
if (!fc->default_permissions)
|
|
attr->ia_valid |= ATTR_FORCE;
|
|
|
|
err = setattr_prepare(dentry, attr);
|
|
if (err)
|
|
return err;
|
|
|
|
if (attr->ia_valid & ATTR_OPEN) {
|
|
if (fc->atomic_o_trunc)
|
|
return 0;
|
|
file = NULL;
|
|
}
|
|
|
|
if (attr->ia_valid & ATTR_SIZE)
|
|
is_truncate = true;
|
|
|
|
if (is_truncate) {
|
|
fuse_set_nowrite(inode);
|
|
set_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
|
|
if (trust_local_cmtime && attr->ia_size != inode->i_size)
|
|
attr->ia_valid |= ATTR_MTIME | ATTR_CTIME;
|
|
}
|
|
|
|
memset(&inarg, 0, sizeof(inarg));
|
|
memset(&outarg, 0, sizeof(outarg));
|
|
iattr_to_fattr(attr, &inarg, trust_local_cmtime);
|
|
if (file) {
|
|
struct fuse_file *ff = file->private_data;
|
|
inarg.valid |= FATTR_FH;
|
|
inarg.fh = ff->fh;
|
|
}
|
|
if (attr->ia_valid & ATTR_SIZE) {
|
|
/* For mandatory locking in truncate */
|
|
inarg.valid |= FATTR_LOCKOWNER;
|
|
inarg.lock_owner = fuse_lock_owner_id(fc, current->files);
|
|
}
|
|
fuse_setattr_fill(fc, &args, inode, &inarg, &outarg);
|
|
err = fuse_simple_request(fc, &args);
|
|
if (err) {
|
|
if (err == -EINTR)
|
|
fuse_invalidate_attr(inode);
|
|
goto error;
|
|
}
|
|
|
|
if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) {
|
|
make_bad_inode(inode);
|
|
err = -EIO;
|
|
goto error;
|
|
}
|
|
|
|
spin_lock(&fc->lock);
|
|
/* the kernel maintains i_mtime locally */
|
|
if (trust_local_cmtime) {
|
|
if (attr->ia_valid & ATTR_MTIME)
|
|
inode->i_mtime = attr->ia_mtime;
|
|
if (attr->ia_valid & ATTR_CTIME)
|
|
inode->i_ctime = attr->ia_ctime;
|
|
/* FIXME: clear I_DIRTY_SYNC? */
|
|
}
|
|
|
|
fuse_change_attributes_common(inode, &outarg.attr,
|
|
attr_timeout(&outarg));
|
|
oldsize = inode->i_size;
|
|
/* see the comment in fuse_change_attributes() */
|
|
if (!is_wb || is_truncate || !S_ISREG(inode->i_mode))
|
|
i_size_write(inode, outarg.attr.size);
|
|
|
|
if (is_truncate) {
|
|
/* NOTE: this may release/reacquire fc->lock */
|
|
__fuse_release_nowrite(inode);
|
|
}
|
|
spin_unlock(&fc->lock);
|
|
|
|
/*
|
|
* Only call invalidate_inode_pages2() after removing
|
|
* FUSE_NOWRITE, otherwise fuse_launder_page() would deadlock.
|
|
*/
|
|
if ((is_truncate || !is_wb) &&
|
|
S_ISREG(inode->i_mode) && oldsize != outarg.attr.size) {
|
|
truncate_pagecache(inode, outarg.attr.size);
|
|
invalidate_inode_pages2(inode->i_mapping);
|
|
}
|
|
|
|
clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
|
|
return 0;
|
|
|
|
error:
|
|
if (is_truncate)
|
|
fuse_release_nowrite(inode);
|
|
|
|
clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
|
|
return err;
|
|
}
|
|
|
|
static int fuse_setattr(struct dentry *entry, struct iattr *attr)
|
|
{
|
|
struct inode *inode = d_inode(entry);
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct file *file = (attr->ia_valid & ATTR_FILE) ? attr->ia_file : NULL;
|
|
int ret;
|
|
|
|
if (!fuse_allow_current_process(get_fuse_conn(inode)))
|
|
return -EACCES;
|
|
|
|
if (attr->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID)) {
|
|
attr->ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID |
|
|
ATTR_MODE);
|
|
|
|
/*
|
|
* The only sane way to reliably kill suid/sgid is to do it in
|
|
* the userspace filesystem
|
|
*
|
|
* This should be done on write(), truncate() and chown().
|
|
*/
|
|
if (!fc->handle_killpriv) {
|
|
/*
|
|
* ia_mode calculation may have used stale i_mode.
|
|
* Refresh and recalculate.
|
|
*/
|
|
ret = fuse_do_getattr(inode, NULL, file);
|
|
if (ret)
|
|
return ret;
|
|
|
|
attr->ia_mode = inode->i_mode;
|
|
if (inode->i_mode & S_ISUID) {
|
|
attr->ia_valid |= ATTR_MODE;
|
|
attr->ia_mode &= ~S_ISUID;
|
|
}
|
|
if ((inode->i_mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) {
|
|
attr->ia_valid |= ATTR_MODE;
|
|
attr->ia_mode &= ~S_ISGID;
|
|
}
|
|
}
|
|
}
|
|
if (!attr->ia_valid)
|
|
return 0;
|
|
|
|
ret = fuse_do_setattr(entry, attr, file);
|
|
if (!ret) {
|
|
/*
|
|
* If filesystem supports acls it may have updated acl xattrs in
|
|
* the filesystem, so forget cached acls for the inode.
|
|
*/
|
|
if (fc->posix_acl)
|
|
forget_all_cached_acls(inode);
|
|
|
|
/* Directory mode changed, may need to revalidate access */
|
|
if (d_is_dir(entry) && (attr->ia_valid & ATTR_MODE))
|
|
fuse_invalidate_entry_cache(entry);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static int fuse_getattr(const struct path *path, struct kstat *stat,
|
|
u32 request_mask, unsigned int flags)
|
|
{
|
|
struct inode *inode = d_inode(path->dentry);
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
|
|
if (!fuse_allow_current_process(fc))
|
|
return -EACCES;
|
|
|
|
return fuse_update_attributes(inode, stat, NULL, NULL);
|
|
}
|
|
|
|
static const struct inode_operations fuse_dir_inode_operations = {
|
|
.lookup = fuse_lookup,
|
|
.mkdir = fuse_mkdir,
|
|
.symlink = fuse_symlink,
|
|
.unlink = fuse_unlink,
|
|
.rmdir = fuse_rmdir,
|
|
.rename = fuse_rename2,
|
|
.link = fuse_link,
|
|
.setattr = fuse_setattr,
|
|
.create = fuse_create,
|
|
.atomic_open = fuse_atomic_open,
|
|
.mknod = fuse_mknod,
|
|
.permission = fuse_permission,
|
|
.getattr = fuse_getattr,
|
|
.listxattr = fuse_listxattr,
|
|
.get_acl = fuse_get_acl,
|
|
.set_acl = fuse_set_acl,
|
|
};
|
|
|
|
static const struct file_operations fuse_dir_operations = {
|
|
.llseek = generic_file_llseek,
|
|
.read = generic_read_dir,
|
|
.iterate_shared = fuse_readdir,
|
|
.open = fuse_dir_open,
|
|
.release = fuse_dir_release,
|
|
.fsync = fuse_dir_fsync,
|
|
.unlocked_ioctl = fuse_dir_ioctl,
|
|
.compat_ioctl = fuse_dir_compat_ioctl,
|
|
};
|
|
|
|
static const struct inode_operations fuse_common_inode_operations = {
|
|
.setattr = fuse_setattr,
|
|
.permission = fuse_permission,
|
|
.getattr = fuse_getattr,
|
|
.listxattr = fuse_listxattr,
|
|
.get_acl = fuse_get_acl,
|
|
.set_acl = fuse_set_acl,
|
|
};
|
|
|
|
static const struct inode_operations fuse_symlink_inode_operations = {
|
|
.setattr = fuse_setattr,
|
|
.get_link = fuse_get_link,
|
|
.getattr = fuse_getattr,
|
|
.listxattr = fuse_listxattr,
|
|
};
|
|
|
|
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;
|
|
}
|