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- /*
- FUSE: Filesystem in Userspace
- Copyright (C) 2001-2008 Miklos Szeredi <miklos@szeredi.hu>
- This program can be distributed under the terms of the GNU GPL.
- See the file COPYING.
- */
- #include "fuse_i.h"
- #include <linux/pagemap.h>
- #include <linux/file.h>
- #include <linux/fs_context.h>
- #include <linux/sched.h>
- #include <linux/namei.h>
- #include <linux/slab.h>
- #include <linux/xattr.h>
- #include <linux/iversion.h>
- #include <linux/posix_acl.h>
- static void fuse_advise_use_readdirplus(struct inode *dir)
- {
- struct fuse_inode *fi = get_fuse_inode(dir);
- set_bit(FUSE_I_ADVISE_RDPLUS, &fi->state);
- }
- #if BITS_PER_LONG >= 64
- static inline void __fuse_dentry_settime(struct dentry *entry, u64 time)
- {
- entry->d_fsdata = (void *) time;
- }
- static inline u64 fuse_dentry_time(const struct dentry *entry)
- {
- return (u64)entry->d_fsdata;
- }
- #else
- union fuse_dentry {
- u64 time;
- struct rcu_head rcu;
- };
- static inline void __fuse_dentry_settime(struct dentry *dentry, u64 time)
- {
- ((union fuse_dentry *) dentry->d_fsdata)->time = time;
- }
- static inline u64 fuse_dentry_time(const struct dentry *entry)
- {
- return ((union fuse_dentry *) entry->d_fsdata)->time;
- }
- #endif
- static void fuse_dentry_settime(struct dentry *dentry, u64 time)
- {
- struct fuse_conn *fc = get_fuse_conn_super(dentry->d_sb);
- bool delete = !time && fc->delete_stale;
- /*
- * Mess with DCACHE_OP_DELETE because dput() will be faster without it.
- * Don't care about races, either way it's just an optimization
- */
- if ((!delete && (dentry->d_flags & DCACHE_OP_DELETE)) ||
- (delete && !(dentry->d_flags & DCACHE_OP_DELETE))) {
- spin_lock(&dentry->d_lock);
- if (!delete)
- dentry->d_flags &= ~DCACHE_OP_DELETE;
- else
- dentry->d_flags |= DCACHE_OP_DELETE;
- spin_unlock(&dentry->d_lock);
- }
- __fuse_dentry_settime(dentry, time);
- }
- /*
- * FUSE caches dentries and attributes with separate timeout. The
- * time in jiffies until the dentry/attributes are valid is stored in
- * dentry->d_fsdata and fuse_inode->i_time respectively.
- */
- /*
- * Calculate the time in jiffies until a dentry/attributes are valid
- */
- static u64 time_to_jiffies(u64 sec, u32 nsec)
- {
- if (sec || nsec) {
- struct timespec64 ts = {
- sec,
- min_t(u32, nsec, NSEC_PER_SEC - 1)
- };
- return get_jiffies_64() + timespec64_to_jiffies(&ts);
- } else
- return 0;
- }
- /*
- * Set dentry and possibly attribute timeouts from the lookup/mk*
- * replies
- */
- void fuse_change_entry_timeout(struct dentry *entry, struct fuse_entry_out *o)
- {
- fuse_dentry_settime(entry,
- time_to_jiffies(o->entry_valid, o->entry_valid_nsec));
- }
- static u64 attr_timeout(struct fuse_attr_out *o)
- {
- return time_to_jiffies(o->attr_valid, o->attr_valid_nsec);
- }
- u64 entry_attr_timeout(struct fuse_entry_out *o)
- {
- return time_to_jiffies(o->attr_valid, o->attr_valid_nsec);
- }
- static void fuse_invalidate_attr_mask(struct inode *inode, u32 mask)
- {
- set_mask_bits(&get_fuse_inode(inode)->inval_mask, 0, mask);
- }
- /*
- * Mark the attributes as stale, so that at the next call to
- * ->getattr() they will be fetched from userspace
- */
- void fuse_invalidate_attr(struct inode *inode)
- {
- fuse_invalidate_attr_mask(inode, STATX_BASIC_STATS);
- }
- static void fuse_dir_changed(struct inode *dir)
- {
- fuse_invalidate_attr(dir);
- inode_maybe_inc_iversion(dir, false);
- }
- /**
- * Mark the attributes as stale due to an atime change. Avoid the invalidate if
- * atime is not used.
- */
- void fuse_invalidate_atime(struct inode *inode)
- {
- if (!IS_RDONLY(inode))
- fuse_invalidate_attr_mask(inode, STATX_ATIME);
- }
- /*
- * Just mark the entry as stale, so that a next attempt to look it up
- * will result in a new lookup call to userspace
- *
- * This is called when a dentry is about to become negative and the
- * timeout is unknown (unlink, rmdir, rename and in some cases
- * lookup)
- */
- void fuse_invalidate_entry_cache(struct dentry *entry)
- {
- fuse_dentry_settime(entry, 0);
- }
- /*
- * Same as fuse_invalidate_entry_cache(), but also try to remove the
- * dentry from the hash
- */
- static void fuse_invalidate_entry(struct dentry *entry)
- {
- d_invalidate(entry);
- fuse_invalidate_entry_cache(entry);
- }
- static void fuse_lookup_init(struct fuse_conn *fc, struct fuse_args *args,
- u64 nodeid, const struct qstr *name,
- struct fuse_entry_out *outarg)
- {
- memset(outarg, 0, sizeof(struct fuse_entry_out));
- args->opcode = FUSE_LOOKUP;
- args->nodeid = nodeid;
- args->in_numargs = 1;
- args->in_args[0].size = name->len + 1;
- args->in_args[0].value = name->name;
- args->out_numargs = 1;
- args->out_args[0].size = sizeof(struct fuse_entry_out);
- args->out_args[0].value = outarg;
- }
- /*
- * Check whether the dentry is still valid
- *
- * If the entry validity timeout has expired and the dentry is
- * positive, try to redo the lookup. If the lookup results in a
- * different inode, then let the VFS invalidate the dentry and redo
- * the lookup once more. If the lookup results in the same inode,
- * then refresh the attributes, timeouts and mark the dentry valid.
- */
- static int fuse_dentry_revalidate(struct dentry *entry, unsigned int flags)
- {
- struct inode *inode;
- struct dentry *parent;
- struct fuse_mount *fm;
- struct fuse_inode *fi;
- int ret;
- inode = d_inode_rcu(entry);
- if (inode && fuse_is_bad(inode))
- goto invalid;
- else if (time_before64(fuse_dentry_time(entry), get_jiffies_64()) ||
- (flags & LOOKUP_REVAL)) {
- struct fuse_entry_out outarg;
- FUSE_ARGS(args);
- struct fuse_forget_link *forget;
- u64 attr_version;
- /* For negative dentries, always do a fresh lookup */
- if (!inode)
- goto invalid;
- ret = -ECHILD;
- if (flags & LOOKUP_RCU)
- goto out;
- fm = get_fuse_mount(inode);
- forget = fuse_alloc_forget();
- ret = -ENOMEM;
- if (!forget)
- goto out;
- attr_version = fuse_get_attr_version(fm->fc);
- parent = dget_parent(entry);
- fuse_lookup_init(fm->fc, &args, get_node_id(d_inode(parent)),
- &entry->d_name, &outarg);
- ret = fuse_simple_request(fm, &args);
- dput(parent);
- /* Zero nodeid is same as -ENOENT */
- if (!ret && !outarg.nodeid)
- ret = -ENOENT;
- if (!ret) {
- fi = get_fuse_inode(inode);
- if (outarg.nodeid != get_node_id(inode) ||
- (bool) IS_AUTOMOUNT(inode) != (bool) (outarg.attr.flags & FUSE_ATTR_SUBMOUNT)) {
- fuse_queue_forget(fm->fc, forget,
- outarg.nodeid, 1);
- goto invalid;
- }
- spin_lock(&fi->lock);
- fi->nlookup++;
- spin_unlock(&fi->lock);
- }
- kfree(forget);
- if (ret == -ENOMEM)
- goto out;
- if (ret || fuse_invalid_attr(&outarg.attr) ||
- fuse_stale_inode(inode, outarg.generation, &outarg.attr))
- goto invalid;
- forget_all_cached_acls(inode);
- fuse_change_attributes(inode, &outarg.attr,
- entry_attr_timeout(&outarg),
- attr_version);
- fuse_change_entry_timeout(entry, &outarg);
- } else if (inode) {
- fi = get_fuse_inode(inode);
- if (flags & LOOKUP_RCU) {
- if (test_bit(FUSE_I_INIT_RDPLUS, &fi->state))
- return -ECHILD;
- } else if (test_and_clear_bit(FUSE_I_INIT_RDPLUS, &fi->state)) {
- parent = dget_parent(entry);
- fuse_advise_use_readdirplus(d_inode(parent));
- dput(parent);
- }
- }
- ret = 1;
- out:
- return ret;
- invalid:
- ret = 0;
- goto out;
- }
- #if BITS_PER_LONG < 64
- static int fuse_dentry_init(struct dentry *dentry)
- {
- dentry->d_fsdata = kzalloc(sizeof(union fuse_dentry),
- GFP_KERNEL_ACCOUNT | __GFP_RECLAIMABLE);
- return dentry->d_fsdata ? 0 : -ENOMEM;
- }
- static void fuse_dentry_release(struct dentry *dentry)
- {
- union fuse_dentry *fd = dentry->d_fsdata;
- kfree_rcu(fd, rcu);
- }
- #endif
- static int fuse_dentry_delete(const struct dentry *dentry)
- {
- return time_before64(fuse_dentry_time(dentry), get_jiffies_64());
- }
- /*
- * Create a fuse_mount object with a new superblock (with path->dentry
- * as the root), and return that mount so it can be auto-mounted on
- * @path.
- */
- static struct vfsmount *fuse_dentry_automount(struct path *path)
- {
- struct fs_context *fsc;
- struct fuse_mount *parent_fm = get_fuse_mount_super(path->mnt->mnt_sb);
- struct fuse_conn *fc = parent_fm->fc;
- struct fuse_mount *fm;
- struct vfsmount *mnt;
- struct fuse_inode *mp_fi = get_fuse_inode(d_inode(path->dentry));
- struct super_block *sb;
- int err;
- fsc = fs_context_for_submount(path->mnt->mnt_sb->s_type, path->dentry);
- if (IS_ERR(fsc)) {
- err = PTR_ERR(fsc);
- goto out;
- }
- err = -ENOMEM;
- fm = kzalloc(sizeof(struct fuse_mount), GFP_KERNEL);
- if (!fm)
- goto out_put_fsc;
- refcount_set(&fm->count, 1);
- fsc->s_fs_info = fm;
- sb = sget_fc(fsc, NULL, set_anon_super_fc);
- if (IS_ERR(sb)) {
- err = PTR_ERR(sb);
- fuse_mount_put(fm);
- goto out_put_fsc;
- }
- fm->fc = fuse_conn_get(fc);
- /* Initialize superblock, making @mp_fi its root */
- err = fuse_fill_super_submount(sb, mp_fi);
- if (err) {
- fuse_conn_put(fc);
- kfree(fm);
- sb->s_fs_info = NULL;
- goto out_put_sb;
- }
- down_write(&fc->killsb);
- list_add_tail(&fm->fc_entry, &fc->mounts);
- up_write(&fc->killsb);
- sb->s_flags |= SB_ACTIVE;
- fsc->root = dget(sb->s_root);
- /*
- * FIXME: setting SB_BORN requires a write barrier for
- * super_cache_count(). We should actually come
- * up with a proper ->get_tree() implementation
- * for submounts and call vfs_get_tree() to take
- * care of the write barrier.
- */
- smp_wmb();
- sb->s_flags |= SB_BORN;
- /* We are done configuring the superblock, so unlock it */
- up_write(&sb->s_umount);
- /* Create the submount */
- mnt = vfs_create_mount(fsc);
- if (IS_ERR(mnt)) {
- err = PTR_ERR(mnt);
- goto out_put_fsc;
- }
- mntget(mnt);
- put_fs_context(fsc);
- return mnt;
- out_put_sb:
- /*
- * Only jump here when fsc->root is NULL and sb is still locked
- * (otherwise put_fs_context() will put the superblock)
- */
- deactivate_locked_super(sb);
- out_put_fsc:
- put_fs_context(fsc);
- out:
- return ERR_PTR(err);
- }
- /*
- * Get the canonical path. Since we must translate to a path, this must be done
- * in the context of the userspace daemon, however, the userspace daemon cannot
- * look up paths on its own. Instead, we handle the lookup as a special case
- * inside of the write request.
- */
- static void fuse_dentry_canonical_path(const struct path *path,
- struct path *canonical_path)
- {
- struct inode *inode = d_inode(path->dentry);
- //struct fuse_conn *fc = get_fuse_conn(inode);
- struct fuse_mount *fm = get_fuse_mount_super(path->mnt->mnt_sb);
- FUSE_ARGS(args);
- char *path_name;
- int err;
- path_name = (char *)get_zeroed_page(GFP_KERNEL);
- if (!path_name)
- goto default_path;
- args.opcode = FUSE_CANONICAL_PATH;
- args.nodeid = get_node_id(inode);
- args.in_numargs = 0;
- args.out_numargs = 1;
- args.out_args[0].size = PATH_MAX;
- args.out_args[0].value = path_name;
- args.canonical_path = canonical_path;
- args.out_argvar = 1;
- err = fuse_simple_request(fm, &args);
- free_page((unsigned long)path_name);
- if (err > 0)
- return;
- default_path:
- canonical_path->dentry = path->dentry;
- canonical_path->mnt = path->mnt;
- path_get(canonical_path);
- }
- const struct dentry_operations fuse_dentry_operations = {
- .d_revalidate = fuse_dentry_revalidate,
- .d_delete = fuse_dentry_delete,
- #if BITS_PER_LONG < 64
- .d_init = fuse_dentry_init,
- .d_release = fuse_dentry_release,
- #endif
- .d_automount = fuse_dentry_automount,
- .d_canonical_path = fuse_dentry_canonical_path,
- };
- const struct dentry_operations fuse_root_dentry_operations = {
- #if BITS_PER_LONG < 64
- .d_init = fuse_dentry_init,
- .d_release = fuse_dentry_release,
- #endif
- };
- int fuse_valid_type(int m)
- {
- return S_ISREG(m) || S_ISDIR(m) || S_ISLNK(m) || S_ISCHR(m) ||
- S_ISBLK(m) || S_ISFIFO(m) || S_ISSOCK(m);
- }
- bool fuse_invalid_attr(struct fuse_attr *attr)
- {
- return !fuse_valid_type(attr->mode) ||
- attr->size > LLONG_MAX;
- }
- int fuse_lookup_name(struct super_block *sb, u64 nodeid, const struct qstr *name,
- struct fuse_entry_out *outarg, struct inode **inode)
- {
- struct fuse_mount *fm = get_fuse_mount_super(sb);
- FUSE_ARGS(args);
- struct fuse_forget_link *forget;
- u64 attr_version;
- int err;
- *inode = NULL;
- err = -ENAMETOOLONG;
- if (name->len > FUSE_NAME_MAX)
- goto out;
- forget = fuse_alloc_forget();
- err = -ENOMEM;
- if (!forget)
- goto out;
- attr_version = fuse_get_attr_version(fm->fc);
- fuse_lookup_init(fm->fc, &args, nodeid, name, outarg);
- err = fuse_simple_request(fm, &args);
- /* Zero nodeid is same as -ENOENT, but with valid timeout */
- if (err || !outarg->nodeid)
- goto out_put_forget;
- err = -EIO;
- if (!outarg->nodeid)
- goto out_put_forget;
- if (fuse_invalid_attr(&outarg->attr))
- goto out_put_forget;
- *inode = fuse_iget(sb, outarg->nodeid, outarg->generation,
- &outarg->attr, entry_attr_timeout(outarg),
- attr_version);
- err = -ENOMEM;
- if (!*inode) {
- fuse_queue_forget(fm->fc, forget, outarg->nodeid, 1);
- goto out;
- }
- err = 0;
- out_put_forget:
- kfree(forget);
- out:
- return err;
- }
- static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry,
- unsigned int flags)
- {
- int err;
- struct fuse_entry_out outarg;
- struct inode *inode;
- struct dentry *newent;
- bool outarg_valid = true;
- bool locked;
- if (fuse_is_bad(dir))
- return ERR_PTR(-EIO);
- locked = fuse_lock_inode(dir);
- err = fuse_lookup_name(dir->i_sb, get_node_id(dir), &entry->d_name,
- &outarg, &inode);
- fuse_unlock_inode(dir, locked);
- if (err == -ENOENT) {
- outarg_valid = false;
- err = 0;
- }
- if (err)
- goto out_err;
- err = -EIO;
- if (inode && get_node_id(inode) == FUSE_ROOT_ID)
- goto out_iput;
- newent = d_splice_alias(inode, entry);
- err = PTR_ERR(newent);
- if (IS_ERR(newent))
- goto out_err;
- entry = newent ? newent : entry;
- if (outarg_valid)
- fuse_change_entry_timeout(entry, &outarg);
- else
- fuse_invalidate_entry_cache(entry);
- if (inode)
- fuse_advise_use_readdirplus(dir);
- return newent;
- out_iput:
- iput(inode);
- out_err:
- return ERR_PTR(err);
- }
- /*
- * Atomic create+open operation
- *
- * If the filesystem doesn't support this, then fall back to separate
- * 'mknod' + 'open' requests.
- */
- static int fuse_create_open(struct inode *dir, struct dentry *entry,
- struct file *file, unsigned flags,
- umode_t mode)
- {
- int err;
- struct inode *inode;
- struct fuse_conn *fc = get_fuse_conn(dir);
- struct fuse_mount *fm = get_fuse_mount(dir);
- FUSE_ARGS(args);
- struct fuse_forget_link *forget;
- struct fuse_create_in inarg;
- struct fuse_open_out outopen;
- struct fuse_entry_out outentry;
- struct fuse_inode *fi;
- struct fuse_file *ff;
- /* Userspace expects S_IFREG in create mode */
- BUG_ON((mode & S_IFMT) != S_IFREG);
- forget = fuse_alloc_forget();
- err = -ENOMEM;
- if (!forget)
- goto out_err;
- err = -ENOMEM;
- ff = fuse_file_alloc(fm);
- if (!ff)
- goto out_put_forget_req;
- if (!fm->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.opcode = FUSE_CREATE;
- args.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(fm, &args);
- if (err)
- goto out_free_ff;
- err = -EIO;
- if (!S_ISREG(outentry.attr.mode) || invalid_nodeid(outentry.nodeid) ||
- fuse_invalid_attr(&outentry.attr))
- goto out_free_ff;
- ff->fh = outopen.fh;
- ff->nodeid = outentry.nodeid;
- ff->open_flags = outopen.open_flags;
- fuse_passthrough_setup(fc, ff, &outopen);
- 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(NULL, ff, flags);
- fuse_queue_forget(fm->fc, forget, outentry.nodeid, 1);
- err = -ENOMEM;
- goto out_err;
- }
- kfree(forget);
- d_instantiate(entry, inode);
- fuse_change_entry_timeout(entry, &outentry);
- fuse_dir_changed(dir);
- err = finish_open(file, entry, generic_file_open);
- if (err) {
- fi = get_fuse_inode(inode);
- fuse_sync_release(fi, 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 err;
- struct fuse_conn *fc = get_fuse_conn(dir);
- struct dentry *res = NULL;
- if (fuse_is_bad(dir))
- return -EIO;
- 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 */
- file->f_mode |= FMODE_CREATED;
- if (fc->no_create)
- goto mknod;
- err = fuse_create_open(dir, entry, file, flags, mode);
- 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_mount *fm, struct fuse_args *args,
- struct inode *dir, struct dentry *entry,
- umode_t mode)
- {
- struct fuse_entry_out outarg;
- struct inode *inode;
- struct dentry *d;
- int err;
- struct fuse_forget_link *forget;
- if (fuse_is_bad(dir))
- return -EIO;
- forget = fuse_alloc_forget();
- if (!forget)
- return -ENOMEM;
- memset(&outarg, 0, sizeof(outarg));
- args->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(fm, args);
- if (err)
- goto out_put_forget_req;
- err = -EIO;
- if (invalid_nodeid(outarg.nodeid) || fuse_invalid_attr(&outarg.attr))
- 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(fm->fc, forget, outarg.nodeid, 1);
- return -ENOMEM;
- }
- kfree(forget);
- d_drop(entry);
- d = d_splice_alias(inode, entry);
- if (IS_ERR(d))
- return PTR_ERR(d);
- if (d) {
- fuse_change_entry_timeout(d, &outarg);
- dput(d);
- } else {
- fuse_change_entry_timeout(entry, &outarg);
- }
- fuse_dir_changed(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_mount *fm = get_fuse_mount(dir);
- FUSE_ARGS(args);
- if (!fm->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.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(fm, &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_mount *fm = get_fuse_mount(dir);
- FUSE_ARGS(args);
- if (!fm->fc->dont_mask)
- mode &= ~current_umask();
- memset(&inarg, 0, sizeof(inarg));
- inarg.mode = mode;
- inarg.umask = current_umask();
- args.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(fm, &args, dir, entry, S_IFDIR);
- }
- static int fuse_symlink(struct inode *dir, struct dentry *entry,
- const char *link)
- {
- struct fuse_mount *fm = get_fuse_mount(dir);
- unsigned len = strlen(link) + 1;
- FUSE_ARGS(args);
- args.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(fm, &args, dir, entry, S_IFLNK);
- }
- void fuse_flush_time_update(struct inode *inode)
- {
- int err = sync_inode_metadata(inode, 1);
- mapping_set_error(inode->i_mapping, err);
- }
- void fuse_update_ctime(struct inode *inode)
- {
- if (!IS_NOCMTIME(inode)) {
- inode->i_ctime = current_time(inode);
- mark_inode_dirty_sync(inode);
- fuse_flush_time_update(inode);
- }
- }
- static int fuse_unlink(struct inode *dir, struct dentry *entry)
- {
- int err;
- struct fuse_mount *fm = get_fuse_mount(dir);
- FUSE_ARGS(args);
- if (fuse_is_bad(dir))
- return -EIO;
- args.opcode = FUSE_UNLINK;
- args.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(fm, &args);
- if (!err) {
- struct inode *inode = d_inode(entry);
- struct fuse_inode *fi = get_fuse_inode(inode);
- spin_lock(&fi->lock);
- fi->attr_version = atomic64_inc_return(&fm->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(&fi->lock);
- fuse_invalidate_attr(inode);
- fuse_dir_changed(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_mount *fm = get_fuse_mount(dir);
- FUSE_ARGS(args);
- if (fuse_is_bad(dir))
- return -EIO;
- args.opcode = FUSE_RMDIR;
- args.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(fm, &args);
- if (!err) {
- clear_nlink(d_inode(entry));
- fuse_dir_changed(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_mount *fm = get_fuse_mount(olddir);
- FUSE_ARGS(args);
- memset(&inarg, 0, argsize);
- inarg.newdir = get_node_id(newdir);
- inarg.flags = flags;
- args.opcode = opcode;
- args.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(fm, &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_dir_changed(olddir);
- if (olddir != newdir)
- fuse_dir_changed(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 (fuse_is_bad(olddir))
- return -EIO;
- if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
- 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_mount *fm = get_fuse_mount(inode);
- FUSE_ARGS(args);
- memset(&inarg, 0, sizeof(inarg));
- inarg.oldnodeid = get_node_id(inode);
- args.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(fm, &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(&fi->lock);
- fi->attr_version = atomic64_inc_return(&fm->fc->attr_version);
- if (likely(inode->i_nlink < UINT_MAX))
- inc_nlink(inode);
- spin_unlock(&fi->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(fc->user_ns, attr->uid);
- stat->gid = make_kgid(fc->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_mount *fm = get_fuse_mount(inode);
- FUSE_ARGS(args);
- u64 attr_version;
- attr_version = fuse_get_attr_version(fm->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.opcode = FUSE_GETATTR;
- args.nodeid = get_node_id(inode);
- args.in_numargs = 1;
- args.in_args[0].size = sizeof(inarg);
- args.in_args[0].value = &inarg;
- args.out_numargs = 1;
- args.out_args[0].size = sizeof(outarg);
- args.out_args[0].value = &outarg;
- err = fuse_simple_request(fm, &args);
- if (!err) {
- if (fuse_invalid_attr(&outarg.attr) ||
- inode_wrong_type(inode, outarg.attr.mode)) {
- fuse_make_bad(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;
- }
- static int fuse_update_get_attr(struct inode *inode, struct file *file,
- struct kstat *stat, u32 request_mask,
- unsigned int flags)
- {
- struct fuse_inode *fi = get_fuse_inode(inode);
- int err = 0;
- bool sync;
- if (flags & AT_STATX_FORCE_SYNC)
- sync = true;
- else if (flags & AT_STATX_DONT_SYNC)
- sync = false;
- else if (request_mask & READ_ONCE(fi->inval_mask))
- sync = true;
- else
- sync = time_before64(fi->i_time, get_jiffies_64());
- if (sync) {
- forget_all_cached_acls(inode);
- err = fuse_do_getattr(inode, stat, file);
- } else if (stat) {
- generic_fillattr(inode, stat);
- stat->mode = fi->orig_i_mode;
- stat->ino = fi->orig_ino;
- }
- return err;
- }
- int fuse_update_attributes(struct inode *inode, struct file *file)
- {
- /* Do *not* need to get atime for internal purposes */
- return fuse_update_get_attr(inode, file, NULL,
- STATX_BASIC_STATS & ~STATX_ATIME, 0);
- }
- int fuse_reverse_inval_entry(struct fuse_conn *fc, u64 parent_nodeid,
- u64 child_nodeid, struct qstr *name)
- {
- int err = -ENOTDIR;
- struct inode *parent;
- struct dentry *dir;
- struct dentry *entry;
- parent = fuse_ilookup(fc, parent_nodeid, NULL);
- if (!parent)
- return -ENOENT;
- inode_lock_nested(parent, I_MUTEX_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_dir_changed(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 current_in_userns(fc->user_ns);
- 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_mount *fm = get_fuse_mount(inode);
- FUSE_ARGS(args);
- struct fuse_access_in inarg;
- int err;
- BUG_ON(mask & MAY_NOT_BLOCK);
- if (fm->fc->no_access)
- return 0;
- memset(&inarg, 0, sizeof(inarg));
- inarg.mask = mask & (MAY_READ | MAY_WRITE | MAY_EXEC);
- args.opcode = FUSE_ACCESS;
- args.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(fm, &args);
- if (err == -ENOSYS) {
- fm->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_is_bad(inode))
- return -EIO;
- 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);
- u32 perm_mask = STATX_MODE | STATX_UID | STATX_GID;
- if (perm_mask & READ_ONCE(fi->inval_mask) ||
- 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 fuse_readlink_page(struct inode *inode, struct page *page)
- {
- struct fuse_mount *fm = get_fuse_mount(inode);
- struct fuse_page_desc desc = { .length = PAGE_SIZE - 1 };
- struct fuse_args_pages ap = {
- .num_pages = 1,
- .pages = &page,
- .descs = &desc,
- };
- char *link;
- ssize_t res;
- ap.args.opcode = FUSE_READLINK;
- ap.args.nodeid = get_node_id(inode);
- ap.args.out_pages = true;
- ap.args.out_argvar = true;
- ap.args.page_zeroing = true;
- ap.args.out_numargs = 1;
- ap.args.out_args[0].size = desc.length;
- res = fuse_simple_request(fm, &ap.args);
- fuse_invalidate_atime(inode);
- if (res < 0)
- return res;
- if (WARN_ON(res >= PAGE_SIZE))
- return -EIO;
- link = page_address(page);
- link[res] = '\0';
- return 0;
- }
- static const char *fuse_get_link(struct dentry *dentry, struct inode *inode,
- struct delayed_call *callback)
- {
- struct fuse_conn *fc = get_fuse_conn(inode);
- struct page *page;
- int err;
- err = -EIO;
- if (fuse_is_bad(inode))
- goto out_err;
- if (fc->cache_symlinks)
- return page_get_link(dentry, inode, callback);
- err = -ECHILD;
- if (!dentry)
- goto out_err;
- page = alloc_page(GFP_KERNEL);
- err = -ENOMEM;
- if (!page)
- goto out_err;
- err = fuse_readlink_page(inode, page);
- if (err) {
- __free_page(page);
- goto out_err;
- }
- set_delayed_call(callback, page_put_link, page);
- return page_address(page);
- out_err:
- return ERR_PTR(err);
- }
- 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, true);
- return 0;
- }
- static int fuse_dir_fsync(struct file *file, loff_t start, loff_t end,
- int datasync)
- {
- struct inode *inode = file->f_mapping->host;
- struct fuse_conn *fc = get_fuse_conn(inode);
- int err;
- if (fuse_is_bad(inode))
- return -EIO;
- if (fc->no_fsyncdir)
- return 0;
- inode_lock(inode);
- err = fuse_fsync_common(file, start, end, datasync, FUSE_FSYNCDIR);
- if (err == -ENOSYS) {
- fc->no_fsyncdir = 1;
- err = 0;
- }
- inode_unlock(inode);
- return err;
- }
- 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 fuse_conn *fc, 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(fc->user_ns, iattr->ia_uid);
- if (ivalid & ATTR_GID)
- arg->valid |= FATTR_GID, arg->gid = from_kgid(fc->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_inode *fi = get_fuse_inode(inode);
- BUG_ON(!inode_is_locked(inode));
- spin_lock(&fi->lock);
- BUG_ON(fi->writectr < 0);
- fi->writectr += FUSE_NOWRITE;
- spin_unlock(&fi->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_inode *fi = get_fuse_inode(inode);
- spin_lock(&fi->lock);
- __fuse_release_nowrite(inode);
- spin_unlock(&fi->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->opcode = FUSE_SETATTR;
- args->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_mount *fm = get_fuse_mount(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 (fm->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(fm->fc, &args, inode, &inarg, &outarg);
- return fuse_simple_request(fm, &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_mount *fm = get_fuse_mount(inode);
- struct fuse_conn *fc = fm->fc;
- 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);
- bool fault_blocked = false;
- if (!fc->default_permissions)
- attr->ia_valid |= ATTR_FORCE;
- err = setattr_prepare(dentry, attr);
- if (err)
- return err;
- if (attr->ia_valid & ATTR_SIZE) {
- if (WARN_ON(!S_ISREG(inode->i_mode)))
- return -EIO;
- is_truncate = true;
- }
- if (FUSE_IS_DAX(inode) && is_truncate) {
- down_write(&fi->i_mmap_sem);
- fault_blocked = true;
- err = fuse_dax_break_layouts(inode, 0, 0);
- if (err) {
- up_write(&fi->i_mmap_sem);
- return err;
- }
- }
- if (attr->ia_valid & ATTR_OPEN) {
- /* This is coming from open(..., ... | O_TRUNC); */
- WARN_ON(!(attr->ia_valid & ATTR_SIZE));
- WARN_ON(attr->ia_size != 0);
- if (fc->atomic_o_trunc) {
- /*
- * No need to send request to userspace, since actual
- * truncation has already been done by OPEN. But still
- * need to truncate page cache.
- */
- i_size_write(inode, 0);
- truncate_pagecache(inode, 0);
- goto out;
- }
- file = NULL;
- }
- /* Flush dirty data/metadata before non-truncate SETATTR */
- if (is_wb && S_ISREG(inode->i_mode) &&
- attr->ia_valid &
- (ATTR_MODE | ATTR_UID | ATTR_GID | ATTR_MTIME_SET |
- ATTR_TIMES_SET)) {
- err = write_inode_now(inode, true);
- if (err)
- return err;
- fuse_set_nowrite(inode);
- fuse_release_nowrite(inode);
- }
- 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(fc, 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(fm, &args);
- if (err) {
- if (err == -EINTR)
- fuse_invalidate_attr(inode);
- goto error;
- }
- if (fuse_invalid_attr(&outarg.attr) ||
- inode_wrong_type(inode, outarg.attr.mode)) {
- fuse_make_bad(inode);
- err = -EIO;
- goto error;
- }
- spin_lock(&fi->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 fi->lock */
- __fuse_release_nowrite(inode);
- }
- spin_unlock(&fi->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);
- out:
- if (fault_blocked)
- up_write(&fi->i_mmap_sem);
- return 0;
- error:
- if (is_truncate)
- fuse_release_nowrite(inode);
- clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
- if (fault_blocked)
- up_write(&fi->i_mmap_sem);
- 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_is_bad(inode))
- return -EIO;
- 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_is_bad(inode))
- return -EIO;
- if (!fuse_allow_current_process(fc)) {
- if (!request_mask) {
- /*
- * If user explicitly requested *nothing* then don't
- * error out, but return st_dev only.
- */
- stat->result_mask = 0;
- stat->dev = inode->i_sb->s_dev;
- return 0;
- }
- return -EACCES;
- }
- return fuse_update_get_attr(inode, NULL, stat, request_mask, flags);
- }
- 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)
- {
- struct fuse_inode *fi = get_fuse_inode(inode);
- inode->i_op = &fuse_dir_inode_operations;
- inode->i_fop = &fuse_dir_operations;
- spin_lock_init(&fi->rdc.lock);
- fi->rdc.cached = false;
- fi->rdc.size = 0;
- fi->rdc.pos = 0;
- fi->rdc.version = 0;
- }
- static int fuse_symlink_readpage(struct file *null, struct page *page)
- {
- int err = fuse_readlink_page(page->mapping->host, page);
- if (!err)
- SetPageUptodate(page);
- unlock_page(page);
- return err;
- }
- static const struct address_space_operations fuse_symlink_aops = {
- .readpage = fuse_symlink_readpage,
- };
- void fuse_init_symlink(struct inode *inode)
- {
- inode->i_op = &fuse_symlink_inode_operations;
- inode->i_data.a_ops = &fuse_symlink_aops;
- inode_nohighmem(inode);
- }
|